Literature search from ms 29/4/2010

Gorber, S. C. and M. S. Tremblay (2010). "The bias in self-reported obesity from 1976 to 2005: a Canada-US comparison." Obesity 18(2): 354-61.

The objective of this study was to determine whether the bias in self-reported estimates of obesity has changed over time and followed different patterns in Canada and the United States. Using age-standardized data from three waves of the National Health and Nutrition Examination Survey (NHANES) in the United States and the Canadian Community Health Survey (CCHS) and the Canadian Heart Health Survey (CHHS) in Canada, discrepancies were compared between reported and measured estimates of height, weight, and obesity (based on the BMI) from 1976 to 2005. Results indicated that obesity increased in both countries, but rates were higher in the United States. The discrepancy between self-reported and measured obesity was small in the United States with reported data underestimating measured prevalence by about 3%; this stayed relatively constant over time. In Canada, the discrepancy was large and doubled in the past decade (from 4 to 8%). In the United States, self-reported data may be more accurate in monitoring changes in obesity over time, as the estimates have consistently remained about 3% below the measured estimates, whereas in Canada, monitoring obesity based solely on self-reported height and weight may produce inaccurate estimates because of the increasing discrepancy between self-reported and measured data.

Gozal, D. (1998). "Congenital central hypoventilation syndrome: an update." PEDIATRIC PULMONOLOGY 26(4): 273-82.

Awareness of the existence of CCHS has led to increasingly frequent reports of such patients from all over the world. However, the exact pathophysiologic mechanisms underlying the clinical manifestations of this congenital disease entity remain unknown. For the respiratory physiologist, CCHS can be viewed as an experiment of nature that provides an important and unique window into central cardiorespiratory regulation. For the pediatrician, CCHS children represent an unique clinical challenge in coordinating the diagnostic and therapeutic procedures required to enhance the patients' quality of life. [References: 102]

Gozal, D. (2004). "New concepts in abnormalities of respiratory control in children." CURRENT OPINION IN PEDIATRICS 16(3): 305-8.

PURPOSE OF REVIEW: Respiratory control disorders such as apnea of prematurity, apparent life-threatening events, sudden infant death syndrome, and central hypoventilation are relatively frequent conditions in the pediatric age range and are associated with substantial morbidity and mortality. The explosion of technological breakthroughs in biology and medicine has facilitated our understanding of the fundamental mechanisms that govern the development of brain regions underlying respiratory control functions. RECENT FINDINGS: Recent critically important discoveries encompass the identification of neurons that constitute the central respiratory rhythm generator in the brainstem, the conceptual framework allowing for many neurons located in multiple strategic regions within the brain to coordinate central chemosensitivity, the discovery of long-term and short-term plasticity in hypoxic ventilatory regulation, and the recent uncovering of specific gene mutations in children affected with congenital central hypoventilation syndrome. SUMMARY: While the developmental aspects of control breathing are only now being actively explored in the context of our current understanding, it is likely that such efforts will yield important novel approaches to the clinical and pharmacologic management of these disorders in the near future. [References: 47]

Gozal, D. and R. M. Harper (1999). "Novel insights into congenital hypoventilation syndrome." CURRENT OPINION IN PULMONARY MEDICINE 5(6): 335-8.

Congenital central hypoventilation syndrome (CCHS) is a rare and unique condition that may prompt unparalleled approaches to the discovery of genes involved in development of cardiorespiratory control and gas exchange homeostasis. Its higher risk of recurrence in families and its association with Hirschsprung's disease suggest that an underlying genetic mechanism is involved. However, screening for mutations of the receptor tyrosine kinase RET and endothelin 3 has revealed only occasional patients affected by these mutations, therefore suggesting that CCHS may result from disruption of more than a single gene. In recent years, three principal issues have become apparent: 1) the autonomic nervous system is involved universally in CCHS cases, albeit to a varying extent; 2) the use of novel functional imaging approaches incorporating refined stimulus paradigms may provide essential research and clinical insights into localization and assessment of neural sites underlying the phenotypic expression of this syndrome; and 3) efforts to transition patients' nocturnal respiratory support to a noninvasive ventilatory modality should be critically evaluated and pursued, when appropriate, to improve the quality of life for patients and families. [References: 47]

Gozal, D., C. L. Marcus, et al. (1993). "Peripheral chemoreceptor function in children with the congenital central hypoventilation syndrome." JOURNAL OF APPLIED PHYSIOLOGY 74(1): 379-87.

In children with the congenital central hypoventilation syndrome (CCHS), some patients require mechanical ventilation during sleep, whereas others need respiratory assistance even when awake. The cause of this disparity is unclear. We hypothesized that differences in peripheral chemoreceptor response (PCR) could provide an explanatory mechanism for this disparity in clinical manifestations. PCR was measured in five children with CCHS and five sex- and age-matched controls by measuring the ventilatory responses induced by 100% O2 breathing, five tidal breaths of 100% N2, and vital capacity breaths of 5% and 15% CO2 in O2 and 5% CO2-95% N2. Tidal breathing of 100% O2 resulted in similar ventilatory responses in CCHS patients and controls with various changes dependent on the method of analysis of response used. Acute hypoxia by N2 tidal breathing resulted in a 39.2 +/- 22% increase in respiratory rate in CCHS patients and a 15.1 +/- 11.1% increase in controls (P < 0.05), with similar increases in minute ventilation (VE) of 124 +/- 69% and 85 +/- 11%, respectively. Vital capacity breaths of each of the CO2-containing gas mixtures induced similar increases in VE in CCHS patients and controls. The changes in VE obtained with 15% CO2-85% O2 and with 5% CO2-95% N2 were significantly greater than those with 5% CO2-95% O2, suggesting a dose-dependent response as well as additive effects of hypercapnic and hypoxic stimuli. We conclude that the PCR, when assessed by acute hypoxia, hyperoxia, or hypercapnia, is present and intact in CCHS children who are able to sustain adequate ventilation during wakefulness.(ABSTRACT TRUNCATED AT 250 WORDS)

Gozal, D., C. L. Marcus, et al. (1996). "Ventilatory responses to passive leg motion in children with congenital central hypoventilation syndrome." AMERICAN JOURNAL OF RESPIRATORY & CRITICAL CARE MEDICINE 153(2): 761-8.

During exercise, children with congenital central hypoventilation syndrome (CCHS) demonstrate coupling of VE to exercise load, despite the absence of a VE response to changes in FICO2. To assess the effect of movement on VE, we studied six CCHS patients and six matched controls during passive motion in a motor-driven ergocycle at pedaling frequencies (PF) of 6 to 60 rpm. VE, VO2, VCO2, VT, heart rate, respiratory rate, SPO2, and PETCO2 were measured. During steady-state conditions, VE was constant at PF of 0 to 30 rpm, but increased at PF > or = 40 rpm in both controls and CCHS patients (p < 0.005). The increase in respiratory rate in CCHS patients was greater than in controls (p < 0.05) whereas VT increased similarly in both groups. At 60 rpm, VO2 increased in both groups, but VE/VO2 and VE/VCO2 increased in the CCHS patients and remained constant in the controls (P < 0.03; p < 0.04). From PF of 0 to 60, PETCO2 decreased from 47 +/- 7 to 41 +/- 6 mm Hg in the CCHS patients (p < 0.001) but remained unchanged in the controls (38 +/- 3 mm Hg; p = NS). An analysis of on-transient responses at 60 rpm revealed that VE increased immediately with the first breath after onset of motion in both groups, and that comparable differences in ventilatory patterns persisted in the two groups. We conclude that passive leg motion at PF > or = 40 increases VE in both CCHS patients and controls. In controls, VE was tightly coupled to VO2 and VCO2. However, in CCHS patients, passive leg motion elicited normalization of PETCO2.

Gozal, D. and N. Simakajornboon (2000). "Passive motion of the extremities modifies alveolar ventilation during sleep in patients with congenital central hypoventilation syndrome." AMERICAN JOURNAL OF RESPIRATORY & CRITICAL CARE MEDICINE 162(5): 1747-51.

Passive motion of lower extremities (PMLE) elicits significant increases in alveolar ventilation (V A) in awake children with congenital central hypoventilation syndrome (CCHS), who have absent or near absent ventilatory responses to hypercapnia. We hypothesized that PMLE would improve V A during non-rapid eye movement (NREM) sleep. To study this, six patients with CCHS (0.2 to 7 yr of age) were disconnected from mechanical ventilatory support during Stage III-IV NREM, and their feet were passively moved at the ankle, either manually or with a motorized device strapped to their feet at 40 to 50 strokes/min. Holding of the feet without motion served as control (C). From a total of 74 successful trials not associated with sleep state changes, PET(CO(2)) decreased from 58.9 +/- 3.5 to 40.9 +/- 2.6 mm Hg with PMLE (n = 58; p < 0.001), whereas end-tidal carbon dioxide (PET(CO(2))) increased in C (n = 16; 58.8 +/- 3.1 to 60.3 +/- 3.7 mm Hg; PMLE versus C: p < 0.001). PMLE increased respiratory frequency from 10.2 +/- 1.9 to 21.2 +/- 2.7 breaths/min (p < 0.0001). We conclude that PMLE during NREM increases V A possibly via activation of mechanoreceptor-afferent pathways rather than by respiratory entrainment. We speculate that such effect may provide future noninvasive ventilatory support strategies in patients with CCHS and mild phenotypic expression of their disease.

Gravel, R. and Y. Beland (2005). "The Canadian Community Health Survey: mental health and well-being." Canadian Journal of Psychiatry - Revue Canadienne de Psychiatrie 50(10): 573-9.

As part of the Canadian Community Health Survey (CCHS) biennial strategy, the provincial survey component of the first CCHS cycle (Cycle 1.2) focused on different aspects of the mental health and well-being of Canadians living in private dwellings. Moreover, the survey collected data on prevalences of specific mental disorders and problems, use of mental health services, and economic and personal costs of having a mental illness. Data collection began in May 2002 and extended over 8 months. More than 85% of all interviews were conducted face-to-face and used a computer-assisted application. The survey obtained a national response rate of 77%. This paper describes several key aspects of the questionnaire content, the sample design, interviewer training, and data collection procedures. A brief overview of the CCHS regional component (Cycle 1.1) is also given.

Green, S., R. Buchbinder, et al. (2003) Physiotherapy interventions for shoulder pain. Cochrane Database of Systematic Reviews Volume, DOI: 10.1002/14651858.CD004258

BACKGROUND: The prevalence of shoulder disorders has been reported to range from seven to 36% of the population (Lundberg 1969) accounting for 1.2% of all General Practitioner encounters in Australia (Bridges Webb 1992). Substantial disability and significant morbidity can result from shoulder disorders. While many treatments have been employed in the treatment of shoulder disorders, few have been proven in randomised controlled trials. Physiotherapy is often the first line of management for shoulder pain and to date its efficacy has not been established. This review is one in a series of reviews of varying interventions for shoulder disorders, updated from an earlier Cochrane review of all interventions for shoulder disorder. OBJECTIVES: To determine the efficacy of physiotherapy interventions for disorders resulting in pain, stiffness and/or disability of the shoulder. SEARCH STRATEGY: MEDLINE, EMBASE, the Cochrane Clinical Trials Regiter and CINAHL were searched 1966 to June 2002. The Cochrane Musculoskeletal Review Group's search strategy was used and key words gained from previous reviews and all relevant articles were used as text terms in the search. SELECTION CRITERIA: Each identified study was assessed for possible inclusion by two independent reviewers. The determinants for inclusion were that the trial be of an intervention generally delivered by a physiotherapist, that treatment allocation was randomised; and that the study population be suffering from a shoulder disorder, excluding trauma and systemic inflammatory diseases such as rheumatoid arthritis. DATA COLLECTION AND ANALYSIS: The methodological quality of the included trials was assessed by two independent reviewers according to a list of predetermined criteria, which were based on the PEDro scale specifically designed for the assessment of validity of trials of physiotherapy interventions. Outcome data was extracted and entered into Revman 4.1. Means and standard deviations for continuous outcomes and number of events for binary outcomes were extracted where available from the published reports. All standard errors of the mean were converted to standard deviation. For trials where the required data was not reported or not able to be calculated, further details were requested from first authors. If no further details were provided, the trial was included in the review and fully described, but not included in the meta-analysis. Results were presented for each diagnostic sub group (rotator cuff disease, adhesive capsulitis, anterior instability etc) and, where possible, combined in meta-analysis to give a treatment effect across all trials. MAIN RESULTS: Twenty six trials met inclusion criteria. Methodological quality was variable and trial populations were generally small (median sample size = 48, range 14 to 180). Exercise was demonstrated to be effective in terms of short term recovery in rotator cuff disease (RR 7.74 (1.97, 30.32), and longer term benefit with respect to function (RR 2.45 (1.24, 4.86). Combining mobilisation with exercise resulted in additional benefit when compared to exercise alone for rotator cuff disease. Laser therapy was demonstrated to be more effective than placebo (RR 3.71 (1.89, 7.28) for adhesive capsulitis but not for rotator cuff tendinitis. Both ultrasound and pulsed electromagnetic field therapy resulted in improvement compared to placebo in pain in calcific tendinitis (RR 1.81 (1.26, 2.60) and RR 19 (1.16, 12.43) respectively). There is no evidence of the effect of ultrasound in shoulder pain (mixed diagnosis), adhesive capsulitis or rotator cuff tendinitis. When compared to exercises, ultrasound is of no additional benefit over and above exercise alone. There is some evidence that for rotator cuff disease, corticosteroid injections are superior to physiotherapy and no evidence that physiotherapy alone is of benefit for Adhesive Capsulitis AUTHORS' CONCLUSIONS: The small sample sizes, variable methodological quality and heterogeneity in terms of population studied, physiotherapy intervention employed and length of follow up of randomised controlled trials of physiotherapy interventions results in little overall evidence to guide treatment. There is evidence to support the use of some interventions in specific and circumscribed cases. There is a need for trials of physiotherapy interventions for specific clinical conditions associated with shoulder pain, for shoulder pain where combinations of physiotherapy interventions, as well as, physiotherapy interventions as an adjunct to other, non physiotherapy interventions are compared. This is more reflective of current clinical practice. Trials should be adequately powered and address key methodological criteria such as allocation concealment and blinding of outcome assessor. SOME PHYSIOTHERAPY INTERVENTIONS ARE EFFECTIVE FOR SHOULDER PAIN IN SOME CASES.: There is a high prevalence of shoulder disorders in the community. Shoulder disorders can result in considerable pain and disability. Physiotherapy is often the first line of treatment for shoulder disorder. Twenty-six trials presented sufficient data to be included in meta-analysis. There is some evidence from methodologically weak trials to indicate that some physiotherapy interventions are effective for some specific shoulder disorders. The results overall provide little evidence to guide treatment. There is a clear need for further high quality trials of physiotherapy interventions, including trials using combinations of modalities, in the treatment of shoulder disorders.
Gregoire, M. J., C. Pernot, et al. (1983). "[Chromosome 11 and cancer]." Journal de Genetique Humaine 31(1): 31-6.

Two cases with chromosome 11 anomaly related to cancer are reported. The first one has a pericentric inversion (inv. p14 q12) with sympathoblastoma and Ondine's curse. The second one has a deletion (11p13) with aniridia and catalase deficiency but without Wilms tumor at two year of age. Retinoblastoma, nephroblastoma and sympathoblastoma may be related to genome modification. The mechanism of oncogenesis are discussed.

Gremmo, G., R. Mettey, et al. (1988). "Congenital alveolar hypoventilation of central origin or Ondine's curse. [French]." Medecine Infantile 95(2): 109-118+120-122.

Grigg-Damberger, M. and A. Wells (2009). "Central congenital hypoventilation syndrome: changing face of a less mysterious but more complex genetic disorder." Seminars in Respiratory & Critical Care Medicine 30(3): 262-74.

Central congenital hypoventilation syndrome (CCHS) is a disorder in which affected individuals fail to breathe during sleep despite progressive hypercapnia and hypoxia. Discovery of the genetic link between PHOX2B gene mutations and CCHS represents a breakthrough in the diagnosis of CCHS, identification of patients with late-onset central hyperventilation syndrome (LO-CHS), association of mutated alleles with disease severity, and clues to the pathophysiology responsible for the disorder. CCHS is a neurocristopathy, and affected individuals are more likely to have disorders of the autonomic nervous system, Hirschsprung disease, and neural crest tumors. Most CCHS patients harbor sporadic mutations, but identification of an affected individual should trigger evaluation of family members because inherited mutations are transmitted in an autosomal dominant fashion. Management of CCHS and LO-CHS is primarily directed at optimizing respiratory status, most often with nighttime mechanical ventilatory support and monitoring with polysomnography. Multidisciplinary care is also necessary to promote better outcomes and long-term survival. [References: 76]
Grillet, N., V. Dubreuil, et al. (2003). "Dynamic Expression of RGS4 in the Developing Nervous System and Regulation by the Neural Type-Specific Transcription Factor Phox2b." JOURNAL OF NEUROSCIENCE 23(33): 10613-10621.

Previous studies have shown that members of the family of regulators of G-protein signaling (RGS), including RGS4, have a discrete expression pattern in the adult brain (Gold et al., 1997). Here, we describe for RGS4 a distinct, mostly transient phase of neuronal expression, during embryonic development: transcription of RGS4 occurs in a highly dynamic manner in a small set of peripheral and central neuronal precursors. This expression pattern overlaps extensively with that of the paired-like homeodomain protein Phox2b, a determinant of neuronal identity. In embryos deficient for Phox2b, RGS4 expression is downregulated in the locus coeruleus, sympathetic ganglia, and cranial motor and sensory neurons. Moreover, Phox2b cooperates with the basic helix-loop-helix protein Mash1 to transiently switch on RGS4 after ectopic expression in the chicken spinal cord. Intriguingly, we also identify a heterotrimeric G-protein alpha-subunit, gustducin, as coexpressed with RGS4 in developing facial motor neurons, also under the control of Phox2b. Altogether, these data identify components of the heterotrimeric G-protein signaling pathway as part of the type-specific program of neuronal differentiation.

Gronli, J. O., B. A. Santucci, et al. (2008). "Congenital central hypoventilation syndrome: PHOX2B genotype determines risk for sudden death." PEDIATRIC PULMONOLOGY 43(1): 77-86.

OBJECTIVE: Children with Congenital Central Hypoventilation Syndrome (CCHS) have cardiovascular symptoms consistent with the autonomic nervous system dysregulation/dysfunction (ANSD) phenotype. We hypothesized that children with CCHS would have a relationship between PHOX2B genotype and two clinically applicable cardiovascular measures of ANSD: duration of longest r-r interval and longest corrected QT interval (QTc). MATERIALS AND METHODS: We studied 501 days of Holter recordings from 39 individuals with PHOX2B mutation-confirmed CCHS, and analyzed longest r-r and QTc intervals with respect to PHOX2B genotype. RESULTS: We determined that longest r-r interval varied by genotype (P=0.001), with a positive correlation between repeat number and longest r-r interval duration (P=0.0007). Number of children with a longest r-r interval value>or=3 sec varied by genotype (P<0.0001): 0% with the 20/25 genotype, 19% with the 20/26 genotype, and 83% with the 20/27 genotype. Though longest QTc interval did not vary by genotype (P=0.09), all children with CCHS had at least one Holter with a QTc interval>450 msec, and percent of time with QTc>450 msec exceeded published values. The proportion of subjects who received a cardiac pacemaker due to prolonged r-r interval was greater for the children with the 20/27 genotype (67%) than the 20/25 (0%) or 20/26 genotype (25%) (P=0.01). Among three children who did not receive a cardiac pacemaker, but who had r-r intervals>or=3 sec, two died suddenly. CONCLUSIONS: These results confirm a disturbance of cardiac autonomic regulation in CCHS, indicate that PHOX2B genotype is related to the severity of dysregulation, predict the need for cardiac pacemaker, and offer the clinician the potential to avert sudden death. Copyright (c) 2007 Wiley-Liss, Inc.

Guilleminault, C., J. McQuitty, et al. (1982). "Congenital central alveolar hypoventilation syndrome in six infants." PEDIATRICS 70(5): 684-94.

Six infants with congenital alveolar hypoventilation syndrome (CCHS) were seen and observed over several years. Two had an association of CCHS with Hirchsprung's disease. All infants were treated by tracheostomy and mechanical ventilation. Three infants have survived (including one with CCHS and Hirchsprung's disease). However, all survivors have required frequent rehospitalization. The infant with the longest survival (now 4 years of age) has developed significant daytime problems involving the "behavioral control" of ventilation. One infant was considered as a "near miss for sudden infant death syndrome" and became significantly symptomatic after establishment of delta (stage 3-4 non-rapid eye movement) sleep, which normally develops between 2 and 4 months of age. CCHS involves autonomic nervous system dysfunction, and the question of a defect involving the integration of chemoreceptor information more than a direct defect of the central chemoreceptor is discussed.

Guo, S., J. Brush, et al. (1999). "Development of noradrenergic neurons in the zebrafish hindbrain requires BMP, FGF8, and the homeodomain protein soulless/Phox2a." NEURON 24(3): 555-566.

We report that the zebrafish mutation soulless, in which the development of locus coeruleus (LC) noradrenergic (NA) neurons failed to occur, disrupts the homeodomain protein Phox2a. Phox2a is not only necessary but also sufficient to induce Phox2b⁺ dopamine-beta-hydroxylase⁺ and tyrosine hydroxylase⁺ NA neurons in ectopic locations. Phox2a is first detected in LC progenitors in the dorsal anterior hindbrain, and its expression there is dependent on FGF8 from the mid/hindbrain boundary and on optimal concentrations of BMP signal from the epidermal ectoderm/future dorsal neural plate junction. These findings suggest that Phox2a coordinates the specification of LC in part through the induction of Phox2b and in response to cooperating signals that operate along the mediolateral and anteroposterior axes of the neural plate.