Literature search from ms 29/4/2010

Nguyen, A. T., S. F. Anderson, et al. (1995). "Circumscribed choroidal hemangioma." JOURNAL OF THE AMERICAN OPTOMETRIC ASSOCIATION 66(10): 640-5.

BACKGROUND: Circumscribed or solitary choroidal hemangioma is a relatively rare, benign vascular tumor. Because its appearance may mimic more serious intraocular lesions, eye care practitioners should be familiar with differential diagnosis and treatment options. METHODS: A patient presented with an asymptomatic, elevated, red-orange lesion above the macula in the right eye and a history of longstanding unexplained visual acuity loss in the eye. Intraocular lesions such as amelanotic melanoma, metastatic tumor, choroidal osteoma, disciform scar, serous detachment, and central serous chorioretinopathy can appear similar to circumscribed choroidal hemangioma (CCH) on ophthalmoscopy, but may be differentially diagnosed with fluorescein angiography, ultrasonography, and periodic observation. RESULTS: CCH requires various therapeutic options. Until the patient becomes symptomatic from visual loss secondary to serous macular detachment or subretinal neovascular membrane formation, no treatment is necessary. Laser photocoagulation is the preferred therapeutic intervention, and most patients will require a minimum of two sessions. A small percentage of individuals will progress to complete retinal detachment with profound visual loss regardless of therapy. Most CCHs remain stable in size and do not undergo malignant transformation. CONCLUSIONS: CCHs may be overlooked because of their initial subtle clinical appearance with no associated cutaneous or systemic anomaly. Even though CCH is a benign tumor, it may mimic more serious intraocular lesions and require a combination of ancillary tests for proper diagnosis. Depending on visual symptoms or potential threat to vision, management options include periodic observation, laser photocoagulation, cryotherapy, microwave therapy, and possible enucleation. CCH has little or no growth potential, but visual prognosis remains guarded due to significant secondary retinal changes that can occur over the tumor's surface. CCH must be considered in the differential diagnosis of an elevated intraocular lesion.

Nguyen, C. T., L. Fournier, et al. (2005). "Correlates of depressive and anxiety disorders among young Canadians." Canadian Journal of Psychiatry - Revue Canadienne de Psychiatrie 50(10): 620-8.

OBJECTIVE: The current study presents data on the prevalence of depressive and anxiety disorders in the Canadian population aged between 15 and 24 years and examines their potential correlates. METHODS: The study is based on the 2002 Canadian Community Health Survey: Mental Health and Well-Being (CCHS 1.2). This survey was administered to a representative sample of 36,984 Canadians. A subsample of 5673 Canadians aged between 15 and 24 years was available for the analyses. We used descriptive analyses to calculate lifetime and 12-month prevalence of depressive and anxiety disorders, and we used logistic regressions to measure odds ratios. RESULTS: Among Canadian youths, 10.2% had suffered from depressive disorders during their lifetime, whereas 12.1% had suffered from anxiety disorders. For 12-month prevalence, the rates were 6.4% and 6.5% for depressive and anxiety disorders, respectively. Depressive disorders were more frequent among youth aged 20 to 24 years and among those no longer in school. Both disorders were more common among women and people under extreme stress. CONCLUSIONS: The prevalence rates found are comparable with other studies, and most of the correlates are concordant with the literature. Results indicate that there is a turning point for depression between late adolescence and adulthood that could be crucial for intervention planning.

Nielson, D. W. and P. G. Black (1990). "Mask ventilation in congenital central alveolar hypoventilation syndrome." PEDIATRIC PULMONOLOGY 9(1): 44-5.

Nishima, S., K. Tsuda, et al. (1982). "Primary alveolar hypoventilation syndrome (Ondine's curse) in a child. [Japanese]." Respiration Research 1(2): 266-269.

Primary alveloar hypoventilation syndrome, or Ondine's curse, is a very rare disease, which is characterized by disfunction of respiratory chemoreceptors. We report a girl with sleep apnea and cyanosis throughout 4 year old. The sensitivity to carbon dioxide, measured by mouth-occlusion pressure (P0.1) is abnormal even on asymptomatic period. The value of transcutaneous PC0₂ is elevated to more than 120mmHg in oxygen inhalation during sleep.
Nolte, D. and H. G. Lasch (1974). "[Primary hypoventilation syndrome (Ondine's curse syndrome) (author's transl)]." Klinische Wochenschrift 52(16): 781-6.

Nord, M., M. D. Hooper, et al. (2008). "Household-level income-related food insecurity is less prevalent in Canada than in the United States." Journal of Hunger and Environmental Nutrition 3(1): 17-35.

Food security-consistent access to enough food for an active, healthy life-is essential for health and good nutrition. We examine differences between Canada and the United States in the prevalence and distribution of household-level, income-related food insecurity as a step toward understanding effects of economic, policy, and program factors on food security. We use nationally representative data on the food security of Canadian households from the 2004 Canadian Community Health Survey Cycle 2.2 (CCHS 2.2) and United States households from the 2003, 2004, and 2005 Current Population Survey Food Security Supplements (CPS-FSS). The two surveys used the same 18-item Household Food Security Survey Module, but Health Canada and the United States Department of Agriculture combined responses in somewhat different ways to determine the food security status of households. We examine effects of the methodological differences. Then, applying the Health Canada classification protocol to the data from both countries, we compare Canadian and US food insecurity rates nationally and for selected subpopulations. Food insecurity was substantially less prevalent in Canada than in the United States (9.0% vs 14.1% using the Canadian adult food security measure). The difference was larger in households with children, for which the prevalence rate of food insecurity in Canada was about half that in the United States. These differences reflected primarily differences in food insecurity prevalence rates within each income adequacy range rather than differences in income distribution between the two countries. copyright 2008 by The Haworth Press.
Normand, J., J. F. Brule, et al. (1990). "Diaphragmatic paralysis. Diagnosis, prognostic evaluation, phrenic nerve stimulation. [French]." Annales de readaptation et de medecine physique 33(2): 151-157.

Electromyography and phrenic nerve stimulation are helpful for studying diaphragmatic paralysis. In unilateral paralysis, those investigations confirm the phrenic nerve damage. They are useful in prognostic evaluation. Sometimes, they allow a recovery to be found before fluoroscopy. In bilateral paralysis, the electrophysiological state of phrenic nerve function is determined by an assessment of the conduction time, the diaphragm muscle action potential and the strength of contraction of the diaphragm at fluoroscopy, in patients who are evaluated as candidates for diaphragm pacing. The main indications are: - respiratory paralysis after cervical spinal cord injury above the origin of the phrenic motor neurons, - the chronic central hypoventilation syndrome (sleep apnea or Ondine's Curse). These patients can become partially or completely independent of conventional respirators.

Nowak, L. G., M. H. J. Munk, et al. (1999). "Cross-correlation study of the temporal interactions between areas V1 and V2 of the macaque monkey." JOURNAL OF NEUROPHYSIOLOGY 81(3): 1057-1074.

Cross-correlation studies performed in cat visual cortex have shown that neurons in different cortical areas of the same hemisphere or in corresponding areas of opposite hemispheres tend to synchronize their activities. The presence of synchronization may be related to the parallel organization of the cat visual system, in which different cortical areas can be activated in parallel from the lateral geniculate nucleus. We wanted to determine whether interareal synchronization of firing can also be observed in the monkey, in which cortical areas are thought to be organized in a hierarchy spanning different levels. Cross-correlation histograms (CCHs) were calculated from pairs of single or pairs of multiunit activities simultaneously recorded in areas V1 and V2 of paralyzed and anesthetized macaque monkeys. Moving bars and flashed bars were used as stimuli. The shift predictor was calculated and subtracted from the raw CCH to reveal interactions of neuronal origin in isolation. Significant CCH peaks, indicating interactions of neuronal origin, were obtained in 11% of the dual single-unit recordings and 46% of the dual multiunit recordings with moving bars. The incidence of nonflat CCHs with flashed bars was 29 and 78%, respectively. For the pairs of recording sites where both flashed and moving stimuli were used, the incidences of significant CCHs were very similar. Three types of peaks were distinguished on the basis of their width at half- height: T (< 16 ms), C (between 16 and 180 ms), and H peaks (>180 ms). T peaks were very rarely observed (<1% in single-unit recordings). H peaks were observed in 7-16% of the single-unit CCHs, and C peaks in 6-16%, depending on the stimulus used. C and H peaks were observed more often when the receptive fields were overlapping or distant by <2degrees. To test for the presence of synchronization between neurons in areas V1 and V2, we measured the position of the CCH peak with respect to the origin of the time axis of the CCH. Only in the case of a few T peaks did we find displaced peaks, indicating a possible drive of the V2 neuron by the simultaneously recorded V1 cell. All the other peaks were either centered on the origin or overlapped the origin of time with their upper halves. Thus similarly to what has been reported for the cat, neurons belonging to different cortical areas in the monkey tend to synchronize the time of emission of their action potentials with three different levels of temporal precision. For peaks calculated from flashed stimuli, we compared the peak position with the difference between latencies of V1 and V2 neurons. There was a clear correlation for single-unit pairs in the case of C peaks. Thus the position of a C peak on the time axis appears to reflect the order of visual activation of the correlated neurons. The coupling strength for H peaks was smaller during visual drive compared with spontaneous activity. On the contrary, C peaks were seen more often and were stronger during visual stimulation than during spontaneous activity. This suggests that C-type synchronization is associated with the processing of visual information. The origin of synchronized activity in a serially organized system is discussed.
Nowak, L. G., M. H. J. Munk, et al. (1995). "Structural basis of cortical synchronization. I. Three types of interhemispheric coupling." JOURNAL OF NEUROPHYSIOLOGY 74(6): 2379-2400.

1. Single-unit and multiunit activities were recorded at the area 17-18 border of each cortical hemisphere in paralyzed cats anesthetized with nitrous oxide supplemented with halothane. Cross-correlation histograms (CCHs) were computed between 86 pairs of single units and 99 pairs of multiunit activities. Visually evoked peaks in the CCHs were removed by subtracting the shift predictor. 2. Three types of CCH peaks were observed: T peaks with narrow widths (4-28 ms), C peaks with intermediate widths (30100 ms), and H peaks with large widths (100-1,000 ms). Osciliatory coupling was observed rarely. This tripartite distribution of CCH peaks is similar to that reported in an earlier study on the temporal coupling between areas 17 and 18. Different types of peaks occurred in isolation or in combination. Combination of different peak types was more often observed in multiunit recordings. 3. CCH peaks of all types were usually centered, meaning that units in opposite hemispheres tend to synchronize their discharges. 4. T peaks were observed almost exclusively for units with overlapping receptive fields and preferentially for units with similar optimal orientations. No dependence on receptive field position or optimal orientation was observed for the encounter rate of C and H peaks. 5. A new method, called the peristimulus CCH, was developed to study the time course of the temporal coupling. This showed that H peaks can occur during visual stimulation and that their time course follows that of the visual responses of the coupled neurons. 6. Using one single bar or two simultaneously presented light bars as stimuli, we studied the effect of visual stimulation on the strength of H coupling. This showed that H coupling observed under stimulation with a single moving light bar can be completely abolished, with little change in visual responses, when the stimulus is changed to two noncoherently moving bars. This was related to a strong decrease of the H peaks in the autocorrelograms. 7. These results demonstrate that T, C, and H peaks constitute, together with high-frequency oscillations, universal forms of temporal coupling between neurons located in different cortical areas. The following paper reports on the effects of cortical lesions on the encounter rate and strength of these different types of coupling.

O'Brien, L. M., C. R. Holbrook, et al. (2005). "Autonomic function in children with congenital central hypoventilation syndrome and their families." CHEST 128(4): 2478-84.

STUDY OBJECTIVES: Congenital central hypoventilation syndrome (CCHS) is a genetic disorder characterized by failure of automatic control of breathing in the absence of obvious anatomic lesions. There have been several reports suggesting that CCHS patients display autonomic dysregulation. Pulse arterial tonometry (PAT) is a novel technique that provides noninvasive moment-to-moment measurements of sympathetic tone changes to the cutaneous vascular bed. We hypothesized that autonomic function as measured by PAT would be altered in children with CCHS. DESIGN: Prospective study. SETTING: CCHS Family Conference, Orlando, FL, and the local community in Louisville, KY. PARTICIPANTS: Nineteen CCHS patients and 31 parents as well as 24 control children and 15 adult control subjects. INTERVENTIONS: Children with CCHS and their parents underwent sympathetic challenges (vital capacity sigh and cold hand pressor test) and a test of reactive hyperemia (brachial artery occlusion) while PAT was continuously monitored from the right hand. Control children and control adults underwent the same procedure. MEASUREMENTS AND RESULTS: The maximal change of the PAT signal compared to the preceding baseline was averaged and expressed as percentage change for each of the challenges. The magnitude of sympathetic discharge-induced attenuation of PAT signal following a sigh was reduced in CCHS children compared to control subjects for both the vital capacity sighs and the cold hand pressor test. There were no differences observed in the magnitude of PAT attenuation between parents of children with CCHS and control adults. No differences were observed between either CCHS and control subjects or CCHS parents and adult control subjects for the brachial artery occlusion test. CONCLUSION: CCHS patients show an attenuated response to endogenous sympathetic stimulation, supporting the presence of autonomic nervous system dysfunction as a consistent feature of this condition. No differences were found in parents of children with CCHS compared to control adults, consistent with the finding that CCHS is primarily the result of a de novo gene mutation.

O'Brien, M. J., L. A. Van Eykern, et al. (1987). "Transcutaneous respiratory electromyographic monitoring." CRITICAL CARE MEDICINE 15(4): 294-299.

The integrated diaphragm electromyogram (EMG) signal reflects function from the inspiratory centers to the neuromuscular junction. The feasibility and potential value of transcutaneous diaphragm electromyography (tcEMG) was confirmed in a group of infants using two prototype respiratory EMG monitors. Infants were monitored continuously for periods ranging from hours to days. One hundred were monitored for clinical reasons, looking for disordered respiratory behavior, while 47 were studied for technical/experimental reasons. Reliable measurements of diaphragm EMG activity were obtained, provided fully shielded electrode cables were used. Measurements in 28 ventilated infants and one adult confirmed that, unlike impedance and other nonelectrophysiologic measures, tcEMG monitoring is not contaminated by ventilator-induced respiratory movements. The potential value of tcEMG monitoring in ventilated subjects is exemplified by illustrations of: 1) diaphragmatic inactivity from phrenic nerve injury, inadequate central drive, and neuromuscular block; 2) augmented expiratory muscle activity; and 3) progressive increase in inspiratory diaphragmatic activity in the presence of a tension pneumothorax. TcEMG monitoring should prove a worthwhile addition to the available noninvasive respiratory monitoring techniques.

Ochoa-Sepulveda, J. J. and J. J. Ochoa-Amor (2005). "Ondine's curse during pregnancy." Journal of Neurology, Neurosurgery & Psychiatry 76(2): 294.

O'Dell, K., E. Staren, et al. (1987). "Total colonic aganglionosis (Zuelzer-Wilson syndrome) and congenital failure of automatic control of ventilation (Ondine's curse)." JOURNAL OF PEDIATRIC SURGERY 22(11): 1019-20.

We report a case of the rare concurrence of total colonic aganglionosis and central hypoventilation. The relevant literature regarding the association of these syndromes, the reversal of male to female predominance in total colonic aganglionosis v Hirschsprung's disease, their association with pheochromocytoma and neuroblastoma, and the possible etiologic role of cessation of neural crest cell migration, are discussed.
Ogawa, T., M. Kojo, et al. (1993). "Cardio-respiratory control in an infant with Ondine's curse: a multivariate autoregressive modelling approach." JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 42(1): 41-52.

We applied spectral analysis through multivariant autoregressive model fitting [1] to RR interval (RRI) and respiratory (RES) oscillation obtained during quiet sleep in an infant with congenital central hypoventilation syndrome (Ondine's curse), a child with obstructive sleep apnea, and two healthy children. Power spectra, impulse response and noise contribution ratio between RRI and RES oscillation were calculated by using a minicomputer PFU-1200 (FACOM) to determine the structure of the feedback system between RRI and RES within the central nervous system. We found that the respiratory noise contribution ratio to RRI was significantly smaller in Ondine's curse (37 +/- 7.7%, at 0.23 Hz) than in obstructive sleep apnea (90 +/- 6.7%, at 0.39 Hz) and healthy subjects. We postulate that the result shows disturbance of the central autonomic control of breathing and heart rate in Ondine's curse.

Olbrich, H. M., D. Zerbin, et al. (1987). "Auditory brainstem response (ABR) in congenital central alveolar hypoventilation." NEUROPEDIATRICS 18(1): 51-3.

Auditory brainstem responses (ABRs) were studied in a child with congenital central alveolar hypoventilation showing marked depression of respiratory drive during sleep. During wakefulness and normoventilation no ABR abnormalities were found, either at the age of 14 months or five years. ABR recordings during sleep at 14 months of age showed marked wave V latency and wave I to wave V interpeak latency prolongation of about 0.4 ms both for periods of hypoventilation and normoxic hypercapnia. ABR findings of this and other studies carried out in sleep apneas are discussed with respect to brainstem dysfunction associated with varied sleep apnea syndromes.

Olson, T. S., G. E. Woodson, et al. (1992). "Upper airway function in Ondine's curse." Archives of Otolaryngology -- Head & Neck Surgery 118(3): 310-2.

Congenital central alveolar hypoventilation (Ondine's curse) is a rare disorder with absence of automatic control of ventilation but preservation of voluntary breathing. Phrenic pacing, used to treat this condition, is usually not successful without a tracheotomy. We performed fiberoptic videoendoscopy on an affected infant airway. During wakefulness and ventilation by a negative pressure ventilator, the airway was normal, but with sleep onset, passive inspiration produced phasic epiglottic collapse. This case demonstrates the importance of central control in maintaining upper airway patency.

O'Neill, P., R. B. McCole, et al. (2007). "A molecular analysis of neurogenic placode and cranial sensory ganglion development in the shark, Scyliorhinus canicula." DEVELOPMENTAL BIOLOGY 304(1): 156-181.

In order to gain insight into the evolution of the genetic control of the development of cranial neurogenic placodes and cranial sensory ganglia in vertebrates, we cloned and analysed the spatiotemporal expression pattern of six transcription factor genes in a chondrichthyan, the shark Scyliorhinus canicula (lesser-spotted dogfish/catshark). As in other vertebrates, NeuroD is expressed in all cranial sensory ganglia. We show that Pax3 is expressed in the profundal placode and ganglion, strongly supporting homology between the separate profundal ganglion of elasmobranchs and basal actinopterygians and the ophthalmic trigeminal placode-derived neurons of the fused amniote trigeminal ganglion. We show that Pax2 is a conserved pan-gnathostome marker for epibranchial and otic placodes, and confirm that Phox2b is a conserved pan-gnathostome marker for epibranchial placode-derived neurons. We identify Eya4 as a novel marker for the lateral line system throughout its development, expressed in lateral line placodes, sensory ridges and migrating primordia, neuromasts and electroreceptors. We also identify Tbx3 as a specific marker for lateral line ganglia in shark embryos. We use the spatiotemporal expression pattern of these genes to characterise the development of neurogenic placodes and cranial sensory ganglia in the dogfish, with a focus on the epibranchial and lateral line placodes. Our findings demonstrate the evolutionary conservation across all gnathostomes of at least some of the transcription factor networks underlying neurogenic placode development. copyright 2006 Elsevier Inc. All rights reserved.

Onimaru, H., K. Ikeda, et al. (2008). "CO2-sensitive preinspiratory neurons of the parafacial respiratory group express Phox2b in the neonatal rat." JOURNAL OF NEUROSCIENCE 28(48): 12845-12850.

Phox2b protein is a specific marker for neurons in the parafacial region of the ventral medulla, which are proposed to play a role in central chemoreception and postnatal survival. Mutations of PHOX2B cause congenital central hypoventilation syndrome. However, there have been no reports concerning electrophysiological characteristics of these Phox2b-expressing neurons in the parafacial region of the neonate immediately after birth. This region overlaps with the parafacial respiratory group (pFRG) composed predominantly of preinspiratory (Pre-I) neurons that are involved in respiratory rhythm generation. We studied (1) whether pFRG neurons are Phox2b immunoreactive or not and (2) whether they show intrinsic CO2 chemosensitivity. We found that most pFRG/Pre-I neurons were Phox2b immunoreactive and depolarized upon increase in CO2 concentration under condition of action potential-dependent synaptic transmission blockade by tetrodotoxin. We also confirmed that these pFRG neurons expressed neurokinin-1 receptor. They were tyrosine hydroxylase negative and presumed to be glutamatergic. Our findings suggest that Phox2b-expressing parafacial neurons play a role in respiratory rhythm generation as well as central chemoreception and thus are essential for postnatal survival. Copyright copyright 2008 Society for Neuroscience.

Onimaru, H., K. Ikeda, et al. (2009). "Phox2b, RTN/pFRG neurons and respiratory rhythmogenesis." Respiratory Physiology and Neurobiology 168(1-2): 13-18.

Phox2b-expressing cells in the parafacial region of the ventral medulla are proposed to play a role in central chemoreception and postnatal survival. Recent findings in the adult rat and neonatal mouse suggest that the Phox2b-immunoreactive (ir) cell cluster in the rostral ventrolateral medulla is composed of glutamatergic neurons and expresses neurokinin 1 receptor (NK1R), indicating that the cluster may be identical to the retrotrapezoid nucleus. This region overlaps at least partly with the parafacial respiratory group (pFRG) composed predominantly of pre-inspiratory (Pre-I) neurons that are involved in respiratory rhythm generation. Recently, we showed that Pre-I neurons in the parafacial region (pFRG/Pre-I) in neonatal rats are indeed expressing Phox2b and are postsynaptically CO2 sensitive. Our findings suggest that Phox2b-expressing pFRG/Pre-I neurons play a role in respiratory rhythm generation as well as central chemoreception and thus are essential for postnatal survival. In this brief review, we focused on these recent findings and discuss the functional role of pFRG/Pre-I neurons. copyright 2009 Elsevier B.V. All rights reserved.