Literature search from ms 29/4/2010

Lang, U., G. Braems, et al. (1990). "Heart rate alterations in a fetus with Ondine's curse." Gynecologic & Obstetric Investigation 30(2): 124-6.

Langou, R. A., L. S. Cohen, et al. (1978). "Ondine's Curse: hemodynamic response to diaphragm pacing (electrophrenic respiration)." AMERICAN HEART JOURNAL 95(3): 295-300.

The hemodynamic response to diaphragm pacing was studied in eight patients with Ondine's Curse. It was shown that such pacing could lower the pulmonary artery pressure while correction of hypoxemia alone could not. It was demonstrated that on pacing, calculated pulmonary arteriolar resistance decreased and there was normalization of arterial blood gases. The mechanism for these changes was improved alveolar ventilation.
Latchaw, R. E., P. R. L'Heureux, et al. (1982). "Neuroblastoma presenting as central nervous system disease." Ajnr: American Journal of Neuroradiology 3(6): 623-30.

Neuroblastoma may be extremely difficult to recognize, particularly when the tumor presents as a primary central nervous system disease. Central nervous system involvement may be considered as primary intracerebral neuroblastoma, metastases to the cranium from an occult primary, primary intraorbital neuroblastoma originating in the ciliary ganglion, metastatic intraorbital neuroblastoma from an occult primary, primary intraspinal neuroblastoma originating in dorsal root ganglia, intraspinal metastatic disease, and distant effects such as myoclonic encephalopathy. Primary neuroblastoma within the ciliary ganglion and primary intraspinal neuroblastoma are extremely rare entities. Illustrative cases the demonstrate the broad spectrum of neurologic presentations are offered. The second known report of neuroblastoma in association with primary pulmonary hypoventilation (Ondine curse) is included.

Lavorini, F., G. A. Fontana, et al. (2007). "Fog-induced cough with impaired respiratory sensation in congenital central hypoventilation syndrome." AMERICAN JOURNAL OF RESPIRATORY & CRITICAL CARE MEDICINE 176(8): 825-32.

RATIONALE: Congenital central hypoventilation syndrome (CCHS) is a genetic disorder mainly characterized by failure of automatic control of breathing, causing alveolar hypoventilation. Little is known regarding cough in CCHS. Parental reports indicate that patients cough normally during airway infections; however, previous studies have demonstrated no cough response to fog inhalation. OBJECTIVES: To evaluate the sensory and motor components of cough, respiratory sensations, and changes in ventilation evoked by fog inhalation in children with CCHS and in sex- and age-matched control subjects. METHODS: Cough threshold was measured and cough intensity was indexed in terms of cough peak expiratory flow and integrated abdominal electromyographic activity. The pattern of breathing was recorded by inductive plethysmography. Respiratory sensations were also investigated. MEASUREMENTS AND MAIN RESULTS: All control subjects and six of seven patients coughed in response to fog inhalation. The seventh coughed with citric acid aerosol inhalation. Cough threshold values were similar in control subjects (range, 0.40-2.22 ml/min) and patients (range, 0.40-3.26 ml/min). Mean values of cough peak expiratory flow and of integrated abdominal electromyographic activity-related variables during coughing were also similar and corresponded to 80% of those recorded during maximum voluntary cough. Cough appearance was preceded by respiratory sensations and increases (P < 0.01) in ventilation in the control subjects but not in the patients. CONCLUSIONS: Children with CCHS have normal cough threshold and motor responses to fog inhalation. However, the lack of respiratory sensations and the likely related ventilatory changes typically elicited by tussigenic fog concentrations suggest a neural sensory deficit that may increase the risk of respiratory disease in these patients.

Lazarenko, R. M., T. A. Milner, et al. (2009). "Acid sensitivity and ultrastructure of the retrotrapezoid nucleus in Phox2b-EGFP transgenic mice." JOURNAL OF COMPARATIVE NEUROLOGY 517(1): 69-86.

The retrotrapezoid nucleus (RTN) contains noncholinergic noncatecholaminergic glutamatergic neurons that express the transcription factor Phox2b (chemically coded or "cc" RTN neurons). These cells regulate breathing and may be central chemoreceptors. Here we explore their ultrastructure and their acid sensitivity by using two novel BAC eGFPPhox2b transgenic mice (B/G, GENSAT JX99) in which, respectively, 36% and 100% of the cc RTN neurons express the transgene in complete or partial anatomical isolation from other populations of eGFP neurons. All but one of the eGFP-labeled RTN neurons recorded in these mice were acid activated in slices. These cells contained VGLUT2 mRNA, and 50% contained preprogalanin mRNA (determined by single-cell PCR in the B/G mouse). Two neuronal subgroups were revealed, which differed in discharge rate at pH 7.3 (type I [similar to]2; type II [similar to]4 Hz) and the degree of alkalization that silenced the cells (type I 7.4-7.6, type II 7.8-8.0). Medial to the RTN, C1 neurons recorded in a tyrosine hydroxylase-GFP mouse were pH insensitive between pH 6.9 and pH 7.5. Ultrastructural studies demonstrated that eGFP-labeled RTN neurons were surrounded by numerous capillaries and were often in direct contact with glial cells, pericytes, and the basement membrane of capillaries. Terminals contacting large proximal eGFP dendrites formed mainly symmetric, likely inhibitory, synapses. Terminals on more distal eGFP dendrites formed preferentially asymmetric, presumably excitatory, synapses. In sum, C1 cells are pH insensitive, whereas cc RTN neurons are uniformly acid sensitive. The RTN neurons receive inhibitory and excitatory synaptic inputs and may have unfettered biochemical interactions with glial cells and the local microvasculature. copyright 2009 Wiley-Liss, Inc.

Lebel, A., R. Pampalon, et al. (2009). "The geography of overweight in Quebec: a multilevel perspective." Canadian Journal of Public Health Revue Canadienne de Sante Publique. 100(1): 18-23.

OBJECTIVES: Explore the contextual aspects of overweight in Quebec through multilevel modelling, using a purposely designed set of spatial units and a few area-based characteristics. METHODS: Data came from the Canadian Community Health Survey (CCHS Cycle 2.1). Multilevel logistic regressions were performed to test for the presence of an independent contextual effect on overweight and obesity (BMI > or = 25 kg/m2), separately for men and women. Modelling considered individual attributes, including some lifestyle aspects, and contextual characteristics. A geographic grid integrating spatial elements related to overweight and obesity in the literature was developed. Also, an area-level residuals analysis was carried out to identify spatial units presenting higher or lower odds of being overweight. RESULTS: After accounting for individual and area-level characteristics, there remain significant geographic variations in overweight in Quebec. Although this contextual effect is small for men and women, many spatial units differ significantly from the provincial average. There are differences between the geography of overweight in men and women which suggest that socio-economic mechanisms and land use patterns underlying overweight might be different between genders. Also, there is considerable variability within rural and urban areas. CONCLUSION: A complex geography of overweight is revealed. Small-scale studies, as well as methodological and data developments, are needed to deepen our understanding of this geography.

Lee, H., J.-S. Lee, et al. (2005). "Differential expression of a poplar copper chaperone gene in response to various abiotic stresses." Tree Physiology 25(4): 395-401.

Copper chaperone (CCH) is upregulated during Arabidopsis (Arabidopsis thaliana L. Columbia) leaf senescence, suggesting that it mobilizes certain metal ions in leaves and transports them to other growing parts of the plants. The CCHs are also involved in defense mechanisms against oxidative stress in Arabidopsis and tomato (Lycopersicon esculentum Mill. cv. 'Ailsa Craig'). To elucidate the functions of CCH in poplar, we cloned a CCH gene (PoCCH) from Populus (Populus alba x P. tremula var. glandulosa) suspension cells and tested its expression in response to various treatments including heavy metals, plant growth regulators and abiotic stresses. The PoCCH cDNA is 540 bp in length, including a 55-bp 5' noncoding domain, a 258-bp open reading frame (ORF), and 227-bp 3' termination region. The coding region of PoCCH represents a putative 85-amino-acid protein with a molecular weight of 8.9 kDa. The deduced amino acid sequence of the PoCCH gene product is 87 and 78% identical to those of tomato and Arabidopsis, respectively, with a high degree of conservation in both the metal-binding and lysine-rich regions. However, the PoCCH gene product lacks the C-terminal extension identified in Arabidopsis CCH. Southern blot analysis suggested that the PoCCH gene is present in low copy numbers in poplar. The expression of PoCCH increased under copper deprivation conditions. The expression of PoCCH was down-regulated by high concentrations of copper, whereas some metals, such as aluminum and zinc, markedly induced PoCCH, and others including cadmium, cobalt and lead had little effect on PoCCH expression. The plant growth regulator jasmonic acid caused an increase in PoCCH transcript whereas abscisic acid, salicylic acid and gibberellic acid did not. The gene was highly induced when cells were exposed to physical stress by high-speed agitation on a gyratory shaker. Other effective inducers of PoCCH expression in suspension culture were methyl viologen and NaCl. Thus, PoCCH does not respond to all stresses, but responds specifically to certain metals and abiotic stresses that induce oxidative damage. Our results suggest that JA is involved in regulating PoCCH expression in poplar cells.

Lee, P., Y.-N. Su, et al. (2009). "PHOX2B mutation-confirmed congenital central hypoventilation syndrome in a Chinese family: presentation from newborn to adulthood." CHEST 135(2): 537-44.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is characterized by compromised chemoreflexes resulting in sleep hypoventilation. We report a Chinese family with paired-like homeobox 2B (PHOX2B) mutation-confirmed CCHS, with a clinical spectrum from newborn to adulthood, to increase awareness of its various manifestations. METHODS: After identifying central hypoventilation in an adult man (index case), clinical evaluation was performed on the complete family, which consisted of the parents, five siblings, and five offspring. Pulmonary function tests, overnight polysomnography, arterial blood gas measurements, hypercapnia ventilatory response, and PHOX2B gene mutation screening were performed on living family members. Brain MRI, 24-h Holter monitoring, and echocardiography were performed on members with clinically diagnosed central hypoventilation. RESULTS: The index patient and four offspring manifested clinical features of central hypoventilation. The index patients had hypoxia and hypercapnia while awake, polycythemia, and hematocrit levels of 70%. The first and fourth children had frequent cyanotic spells, and both died of respiratory failure. The second and third children remained asymptomatic until adulthood, when they experienced impaired hypercapnic ventilatory response. The third child had nocturnal hypoventilation with nadir pulse oximetric saturation of 59%. Adult-onset CCHS with PHOX2B gene mutation of the + 5 alanine expansions were confirmed in the index patient and the second and third children. The index patient and the third child received ventilator support system bilevel positive airway pressure treatment, which improved the hypoxemia, hypercapnia, and polycythemia without altering their chemosensitivity. CONCLUSIONS: Transmission of late-onset CCHS is autosomal-dominant. Genetic screening of family members of CCHS probands allows for early diagnosis and treatment.

Lemstra, M., C. Neudorf, et al. (2009). "Suicidal ideation: the role of economic and aboriginal cultural status after multivariate adjustment." Canadian Journal of Psychiatry - Revue Canadienne de Psychiatrie 54(9): 589-95.

OBJECTIVE: To determine if Aboriginal (in this paper, First Nations and Metis people) cultural status is independently associated with lifetime suicidal ideation in the Saskatoon Health Region after controlling for other covariates, particularly income status. METHODS: Data collected by Statistics Canada in all 3 cycles of the Canadian Community Health Survey (CCHS) were merged with identical questions asked in February 2007 by the Saskatoon Health Region. The health outcome was lifetime suicidal ideation. The risk indicators included demographics, socioeconomic status, cultural status, behaviours, life stress, health care use, and other health problems. RESULTS: Participants (n = 5948) completed the survey with a response rate of 81.1%. The prevalence of lifetime suicidal ideation was 11.9%. After stratification, it was found that high-income Aboriginal people have similar low levels of suicidal ideation, compared with high-income Caucasian people. The risk-hazard model demonstrated a larger independent effect of income status in explaining the association between Aboriginal cultural status and lifetime suicidal ideation, compared with the independent effect of age. After full multivariate adjustment, Aboriginal cultural status had a substantially reduced association with lifetime suicidal ideation. The odds of lifetime suicidal ideation for Aboriginal people reduced from 3.28 to 1.99 after multivariate adjustment for household income alone. CONCLUSION: The results of this study suggest reductions in lifetime suicidal ideation can be observed in Aboriginal people in Canada by adjusting levels of household income.

Lemstra, M., C. Neudorf, et al. (2008). "Implications of a public smoking ban." Canadian Journal of Public Health Revue Canadienne de Sante Publique. 99(1): 62-5.

OBJECTIVES: Legislation to ban smoking in public places is currently a major area of interest across Canada. The main objectives of the study were to 1) determine the effect of the smoking ban on incidence of acute myocardial infarction, 2) determine if the new legislation altered population-based smoking prevalence, and 3) measure public support for the public smoking ban. METHODS: The city of Saskatoon initiated a public smoking ban on July 1, 2004. We retrospectively reviewed all hospital discharges for acute MI from July 2000 to June 2005. We reviewed CCHS survey information on smoking prevalence for Saskatoon, Saskatchewan and Canada from 2003 to 2005. We prospectively contacted 1,255 Saskatoon residents by telephone to determine support for the public smoking ban. RESULTS: The age-standardized incidence rate of acute MI fell from 176.1 (95% CI 165.3-186.8) cases per 100,000 population (July 1, 2000 to June 30, 2004) to 152.4 (95% CI 135.3-169.3) cases per 100,000 population (July 1, 2004 to June 30, 2005). Smoking prevalence in Saskatoon fell from 24.1% in 2003 (95% CI 20.4-27.7) to 18.2% in 2005 (95% CI 15.7-20.9) while smoking prevalence in Saskatchewan remained unchanged at 23.8% (95% CI 22.6-25.3) and Canada reduced from 22.9% (95% CI 22.5-23.3) to 21.3% (95% CI 20.8-21.8). Seventy-nine percent of Saskatoon residents believed the smoking ban was a good idea. INTERPRETATION: The public smoking ban in Saskatoon, Canada, is associated with reduced incidence rates of acute MI, lower smoking prevalence and high levels of public support.

Leon, T. Y. Y., E. S. W. Ngan, et al. (2009). "Transcriptional regulation of RET by Nkx2-1, Phox2b, Sox10, and Pax3." JOURNAL OF PEDIATRIC SURGERY 44(10): 1904-12.

BACKGROUND: The rearranged during transfection (RET) gene encodes a single-pass receptor whose proper expression and function are essential for the development of enteric nervous system. Mutations in RET regulatory regions are also associated with Hirschsprung disease (HSCR) (aganglionosis of the colon). We previously showed that 2 polymorphisms in RET promoter are associated with the increased risk of HSCR. These single nucleotide polymorphisms overlap with the NK2 homeobox 1 (Nkx2-1) binding motif interrupting the physical interaction of NKX2-1 with the RET promoter and result in reduced RET transcription. In this study, we further delineated Nkx2-1-mediated RET Transcription. METHODS AND RESULTS: First, we demonstrated that PHOX2B, like SOX10 and NKX2-1, is expressed in the mature enteric ganglions of human gut by immunohistochemistry. Second, subsequent dual-luciferase-reporter studies indicated that Nkx2-1 indeed works coordinately with Phox2b and Sox10, but not Pax3, to mediate RET transcription. In addition, identification of Phox2b responsive region in RET promoter further provides solid evidence of the potential functional interaction between Phox2b and RET. CONCLUSION: In sum, Phox2b and Sox10 act together with Nkx2.1 to modify RET signaling and this interaction may also contribute to HSCR susceptibility.

Leonhardt, L. and S. Krause (1982). "Primary hypoventilation syndrome in pseudo Klinefelter's syndrome. [German]." Medizinische Welt 33(4): 135-136.

Interference with the central respiratory regulation can cause hypoventilation syndromes, e.g. the Pickwickian syndrome in adults and the Undine syndrome in children. Hypoparathyroidism can also be accompanied by hypoventilation. In the case of a patient with hypo-adrogenism, the hypoventilation syndrome was observed and the endocrine disorder seemed to have been accompanied by an insufficiency of the central respiratory regulation.

Lesser, D. J., S. L. D. Ward, et al. (2009). "Congenital hypoventilation syndromes." Seminars in Respiratory & Critical Care Medicine 30(3): 339-47.

Although rare, congenital hypoventilation syndromes profoundly impact affected patients and families. In some diseases, such as congenital central hypoventilation syndrome (CCHS), hypoventilation is a key presenting feature. Ventilatory abnormalities may not be immediately evident in other disease states. The clinical aspects of several pediatric hypoventilation syndromes, including CCHS, Chiari type II malformation, Prader-Willi syndrome, familial dysautonomia, and rapid onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation are presented. [References: 72]

Levard, G., N. Boige, et al. (1989). "[Neurocristopathy. The association of Hirschsprung's disease-ganglioneuroma with autonomic nervous system dysfunction in 2 children]." Archives Francaises de Pediatrie 46(8): 595-7.

Two children with the coexistence of long segment Hirschsprung's disease, ganglioneuroblastoma with Ondine's curse in one case and autonomic nervous system impairment in the other are presented. All lesions may be related to aberrations of neural crest cell growth, their migration, or differentiation. A genetic etiology, and the link between Hirschsprung's disease and multiple endocrine adenomatosis is discussed. The combination of Hirschsprung's disease and a neurocristopathy strongly suggests that exploration of the autonomic nervous system and APUD system be carried out.

Levy, R. B., A. D. Reyes, et al. (2008). "Cholinergic modulation of local pyramid-interneuron synapses exhibiting divergent short-term dynamics in rat sensory cortex." BRAIN RESEARCH 1215(C): 97-104.

Acetylcholine (ACh) influences attention, short-term memory, and sleep/waking transitions, through its modulatory influence on cortical neurons. It has been proposed that behavioral state changes mediated by ACh result from its selective effects on the intrinsic membrane properties of diverse cortical inhibitory interneuron classes. ACh has been widely shown to reduce the strength of excitatory (glutamatergic) synapses. But past studies using extracellular stimulation have not been able to examine the effects of ACh on local cortical connections important for shaping sensory processing. Here, using dual intracellular recording in slices of rat somatosensory cortex, we show that reduction of local excitatory input to inhibitory neurons by ACh is coupled to differences in the underlying short-term synaptic plasticity (STP). In synapses with short-term depression, where successive evoked excitatory postsynaptic potentials (EPSPs; > 5 Hz) usually diminish in strength (short-term depression), cholinergic agonist (5-10 muM carbachol (CCh)) reduced the amplitude of the first EPSP in an evoked train, but CCh's net effect on subsequent EPSPs rapidly diminished. In synapses where successive EPSPs increased in strength (facilitation), the effect of CCh on later EPSPs in an evoked train became progressively greater. The effect of CCh on both depressing and facilitating synapses was blocked by the muscarinic antagonist, 1-5 muM atropine. It is suggested that selective influence on STP contributes fundamentally to cholinergic "switching" between cortical rhythms that underlie different behavioral states. copyright 2008 Elsevier B.V. All rights reserved.

Ley, R. (1997). "The Ondine curse, false suffocation alarms, trait-state suffocation fear, and dyspnea-suffocation fear in panic attacks." ARCHIVES OF GENERAL PSYCHIATRY 54(7): 677-8.

Li, A., L. Emond, et al. (2008). "Brainstem catecholaminergic neurons modulate both respiratory and cardiovascular function." Integration in Respiratory Control: From Genes to Systems Advances in Experimental Medicine and Biology. 605: 371-376.

Catecholamine neurons (CA) located in the brainstem project widely in the forebrain, hindbrain and spinal cord to many regions involved in the control of respiratory and cardiovascular function. For example, A6 noradrenergic neurons provide a tonic excitatory stimulus that maintains breathing frequency while A5 neurons provide an inhibitory influence on both cardiovascular and respiratory function to slow breathing frequency and heart rate. Mice with genetic defects that include CA neurons have abnormal respiration and blood pressure. For example, mice heterozygous for Phox2b with CA neuron defects have sleep-disordered breathing, and DBH knockout mice with absent CA cells centrally and peripherally have hypotension. Our hypothesis is that widespread brainstem CA neuron lesions in adult rats would significantly affect cardiorespiratory functions including breathing, chemoreception, blood pressure and heart rate. We produced the widespread brainstem CA neuron lesion by injecting anti-dopamine-beta-hydroxylase-saporin (DBH-SAP) via the 4th ventricle. The lesioned group had a 64-84% loss of A5, A6 and A7 tyrosine hydroxylase immunoreactive (ir) neurons along with 56-64% loss of C1 and C2 phenyl ethanolamine-N methyltransferase (PNMT)-ir neurons over 2-3 weeks. The significant respiratory changes included: (1) a decreased breathing frequency during air and 7% CO2 breathing in both wakefulness and non-REM (NREM) sleep; (2) a reduced ventilatory response to 7% CO2 in wakefulness (-28%) and in NREM sleep (-26%); and (3) increased variability of breathing in REM sleep but not in wakefulness or NREM sleep. Significant cardiovascular changes at two weeks included: (1) an increased MAP by 11.7 mmHg in the room air resting condition; (2) an unaffected cardiovascular response to hypercapnia; and (3) a smaller decrease of MAP in response to hypoxia.Conclusions: Central CA neurons have a net excitatory effect on breathing and chemoreception but a net inhibitory effect on blood pressure. copyright 2008 Springer Science+Business Media, LLC.
Li, Z., Q. Doan, et al. (2010). "Determinants of influenza immunization uptake in Canadian youths." VACCINE 28(19): 3462-6.

OBJECTIVE: To describe rate and determinants of influenza vaccination among Canadian youths. METHODS: We conducted an analysis of cross-sectional data from the Canadian Community Health Survey (CCHS) cycle 3.1 collected by Statistics Canada in 2005. This is a population-based survey collecting information pertaining to the Canadian population health status, health care utilization and health determinants. The CCHS 3.1 included 12,170 respondents age 12-17 years old who answered questions pertaining to influenza vaccination. We used multivariate logistic regression to estimate the odds of having received the influenza vaccination in the last 12 months, adjusting for potential confounders. RESULTS: Less than a quarter of Canadian youth reported receiving the influenza vaccination in the previous year. The most common reason for not getting the vaccination was "did not think it was necessary" (40.82%). Having chronic illness, and being an immigrant was significantly associated with a higher odds of receiving the influenza vaccination, while having an allergy and increasing frequency of alcohol drinking was associated with lower odds of receiving influenza vaccination. Smoking status acted as an effect modifier for many variables except for immigration status. CONCLUSIONS: Influenza vaccination rate in Canadian youths is low. Judgement values on its necessity are a major factor in the decision to receive influenza vaccination. Strategies to involve youths in influenza vaccination programs and campaigns will be essential to achieve better national coverage. Copyright 2010 Elsevier Ltd. All rights reserved.