BACKGROUNDObstructive sleep apnea affects up to 2.9% of children. This study was to determine demographic and clinical characteristics of a group of children with obstructive sleep apnea syndrome (OSAS) as defined by sleep polysomnography (PSG).

METHODSA prospective study was conducted in a public-funded general hospital in Hong Kong of China. Children confirmed to have OSAS by PSG were followed up between January 1997 and December 1998. Tonsillectomy and adenoidectomy (T&A) was offered to those with moderate to severe OSAS, and medication was offered to those with mild OSAS. All children were followed up regularly in the sleep clinic and sleep PSG was repeated for those with marked relapse in symptoms.

RESULTSEighty-nine children (64 boys and 25 girls, mean age 7 years) were confirmed to have OSAS out of 352 children who underwent PSG during the study period. The most common symptoms of OSAS were snoring (100%) and sweating (81%) during sleep and nasal blockage (61%) and sleepiness (34%) during daytime. Severe OSAS occurred in 15 children. Moderate OSAS occurred in 33 children. Forty-one children had mild OSAS. Forty-nine children underwent T&A, 5 (boys, < 5 years) out of whom were found to have recurrent OSAS within 1 year.

CONCLUSIONA male predominance has been found in a group of Hong Kong children with OSAS. Boys undergoing T&A at an early age (< 5 years) will be more likely to develop repeated OSAS.

Adenoidectomy ; Adolescent ; Child ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Male ; Prospective Studies ; Recurrence ; Sleep Apnea, Obstructive ; surgery ; Tonsillectomy

INTRODUCTIONAdults with obstructive sleep apnoea (OSA) are well documented to be at high risk for cardiovascular abnormalities. Growing evidence suggests that OSA is also associated with cardiovascular consequences in children. The purpose of this review is to examine the available data on this association in children.

METHODSPrimary studies were extracted from a MEDLINE search limited to those published between 1970 and 2008. The keywords used included child, sleep disordered breathing, sleep apnoea, snoring, blood pressure and hearts. The relevant articles were selected by consensus between 2 authors.

RESULTSThe results suggested that OSA was consistently associated with hypertension. Meta-analysis of risk of hypertension in those with high apnoea-hypopnoea index was undertaken. A combined odds ratio equal to 3.15 was found (95% confidence interval, 2.01 to 4.93). There was evidence for increased sympathetic activation, decreased arterial distensibility and ventricular hypertrophy in children with OSA.

CONCLUSIONChildhood OSA is associated with blood pressure dysregulation. The association of OSA with other cardiovascular morbidities requires further study in view of the limited data available currently.

Atherosclerosis ; physiopathology ; Blood Pressure ; physiology ; Cardiovascular System ; physiopathology ; Cerebral Arteries ; physiopathology ; Child ; Endothelium, Vascular ; physiopathology ; Heart Rate ; physiology ; Humans ; Hypertension ; physiopathology ; Hypertrophy, Left Ventricular ; physiopathology ; Pulmonary Heart Disease ; physiopathology ; Regional Blood Flow ; Sleep Apnea, Obstructive ; complications ; physiopathology ; Ventricular Function

The availability of human stem cells heralds a new era for in vitro cell-based modeling of neurodevelopmental and neurodegenerative diseases. Adding to the excitement is the discovery that somatic cells of patients can be reprogrammed to a pluripotent state from which neural lineage cells that carry the disease genotype can be derived. These in vitro cell-based models of neurological diseases hold promise for monitoring of disease initiation and progression, and for testing of new drug treatments on the patient-derived cells. In this review, we focus on the prospective applications of different stem cell types for disease modeling and drug screening. We also highlight how the availability of patient-specific induced pluripotent stem cells (iPS cells) offers a unique opportunity for studying and modeling human neurodevelopmental and neurodegenerative diseases in vitro and for testing small molecules or other potential therapies for these disorders. Finally, the limitations of this technology from the standpoint of reprogramming efficiency and therapeutic safety are discussed.
Drug Evaluation, Preclinical ; Humans ; Induced Pluripotent Stem Cells ; cytology ; pathology ; Models, Neurological ; Nervous System Diseases ; physiopathology ; Neural Stem Cells ; pathology ; Neurodegenerative Diseases ; physiopathology

The capability of the central vestibular system in utilizing cues arising from the inner ear determines the ability of animals to acquire the sense of head orientations in the three-dimensional space and to shape postural movements. During development, neurons in the vestibular nucleus (VN) show significant changes in their electrophysiological properties. An age-dependent enhancement of membrane excitability is accompanied by a progressive increase in firing rate and discharge regularity. The coding of horizontal and vertical linear motions also exhibits developmental refinement in VN neurons. Further, modification of cell surface receptors, such as glutamate receptors, of developing VN neurons are well-orchestrated in the course of maturation, thereby regulating synaptic efficacy and spatial coding capacity of these neurons in local circuits. Taken together, these characteristic features of VN neurons contribute to developmental establishment of space-centered coordinates within the brain.
Animals ; Ear, Inner ; physiology ; Electrophysiological Phenomena ; Movement ; Neurons ; physiology ; Rats ; Receptors, Cell Surface ; physiology ; Vestibular Nuclei ; physiology

Epstein-Barr virus (EBV) infection is closely associated with undifferentiated nasopharyngeal carcinoma (NPC), strongly implicating a role for EBV in NPC pathogenesis; conversely, EBV infection is rarely detected in normal nasopharyngeal epithelial tissues. In general, EBV does not show a strong tropism for infecting human epithelial cells, and EBV infection in oropharyngeal epithelial cells is believed to be lytic in nature. To establish life-long infection in humans, EBV has evolved efficient strategies to infect B cells and hijack their cellular machinery for latent infection. Lytic EBV infection in oropharyngeal epithelial cells, though an infrequent event, is believed to be a major source of infectious EBV particles for salivary transmission. The biological events associated with nasopharyngeal epithelial cells are only beginning to be understood with the advancement of EBV infection methods and the availability of nasopharyngeal epithelial cell models for EBV infection studies. EBV infection in human epithelial cells is a highly inefficient process compared to that in B cells, which express the complement receptor type 2 (CR2) to mediate EBV infection. Although receptor(s) on the epithelial cell surface for EBV infection remain(s) to be identified, EBV infection in epithelial cells could be achieved via the interaction of glycoproteins on the viral envelope with surface integrins on epithelial cells, which might trigger membrane fusion to internalize EBV in cells. Normal nasopharyngeal epithelial cells are not permissive for latent EBV infection, and EBV infection in normal nasopharyngeal epithelial cells usually results in growth arrest. However, genetic alterations in premalignant nasopharyngeal epithelial cells, including p16 deletion and cyclin D1 overexpression, could override the growth inhibitory effect of EBV infection to support stable and latent EBV infection in nasopharyngeal epithelial cells. The EBV episome in NPC is clonal in nature, suggesting that NPC develops from a single EBV-infected nasopharyngeal epithelial cell, and the establishment of persistent and latent EBV infection in premalignant nasopharyngeal epithelium may represent an early and critical event for NPC development.
Carcinoma ; Cell Transformation, Neoplastic ; Cells, Cultured ; Epithelial Cells ; Epstein-Barr Virus Infections ; Herpesvirus 4, Human ; Humans ; Nasopharyngeal Neoplasms ; Nasopharynx ; Precancerous Conditions

OBJECTIVEThe literature has shown that cognitive and emotional changes may occur after chronic treatment with glucocorticoids. This might be caused by the suppressive effect of glucocorticoids on hippocampal neurogenesis and cell proliferation. Paroxetine, a selective serotonin reuptake transporter, is a commonly used antidepressant for alleviation of signs and symptoms of clinical depression. It was discovered to promote hippocampal neurogenesis in the past few years and we wanted to investigate its interaction with glucocorticoid in this study.

METHODSAdult rats were given vehicle, corticosterone, paroxetine, or both corticosterone and paroxetine for 14 d. Cell proliferation in the dentate gyrus was quantified using 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry.

RESULTSThe corticosterone treatment suppressed while paroxetine treatment increased hippocampal cell proliferation. More importantly, paroxetine treatment could reverse the suppressive effect of corticosterone on hippocampal cell proliferation.

CONCLUSIONThis may have clinic application in preventing hippocampal damage after glucocorticoid treatment.

Analysis of Variance ; Animals ; Bromodeoxyuridine ; metabolism ; Cell Count ; Cell Proliferation ; drug effects ; Corticosterone ; pharmacology ; Drug Interactions ; Hippocampus ; cytology ; Male ; Neural Inhibition ; drug effects ; Neurons ; drug effects ; Paroxetine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Serotonin Uptake Inhibitors ; pharmacology

PURPOSE: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. METHODS: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. RESULTS: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. CONCLUSION: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.
Aneurysm ; Angiography ; Computer Simulation ; Endovascular Procedures ; Hydrodynamics ; Intracranial Aneurysm* ; Stents ; Ultrasonography ; Ultrasonography, Doppler* ; Ultrasonography, Doppler, Color

No abstract available.
Hong Kong* ; Rehabilitation* ; Stroke*

BACKGROUNDThe neurogenesis in retina of adult mammals is generally abolished, and this renders the retina lack of regenerative capacity. Despite this, there is a small population of nestin-positive cells in the ciliary epithelium which retains neurogenic potential. The present study aimed at investigating the effect of two drugs, corticosterone and paroxetine, on the cell proliferation of the ciliary body.

METHODSAdult Sprague-Dawley rats were given vehicle, corticosterone, paroxetine, or both corticosterone and paroxetine treatment for 14 days. Cell proliferation in the ciliary body was quantified using 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry. Co-labelling of BrdU and stem cell marker was used to phenotype the BrdU immunoreactive cells.

RESULTSCorticosterone treatment suppressed while paroxetine treatment increased the cell proliferation of the ciliary body. Co-labelling with cell markers revealed that the BrdU positive cells also showed nestin expression but not glial fibrillary acidic protein (GFAP).

CONCLUSIONSThe results illustrate that proliferation of retinal progenitor cells situated in ciliary body are subjected to regulation by selective serotonin reuptake inhibitors (SSRI) and corticosteroid, which is similar to our previous findings in neurogenic regions in central nervous system (CNS). Paroxetine treatment could reverse the suppressive effect of corticosterone on ciliary body cell proliferation. This provides information for future investigation of retinal stem cell biology and potential treatment of retinal degenerative diseases.

Adrenal Glands ; drug effects ; pathology ; Animals ; Body Weight ; drug effects ; Cell Proliferation ; drug effects ; Ciliary Body ; cytology ; drug effects ; Corticosterone ; pharmacology ; Immunohistochemistry ; In Vitro Techniques ; Male ; Organ Size ; drug effects ; Paroxetine ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo establish an assay for screening chromosome 22q11 microdeletion efficiently, and apply it for detecting del22q11 in patients with non-syndromic congenital heart defects (CHD).

METHODSSeventy nine patients with non-syndromic CHD and 84 normal controls were genotyped for 8 short tandem repeat (STR) markers located in 22q11 region, by using quantitative fluorescence polymerase chain reaction (QF-PCR).

RESULTSThe average heterozygosity of the STR markers in patients and controls was 0.76 and 0.79, respectively. One patient with Tetralogy of Fallot (TOF) from the 79 CHD cases (1.3%) was found to have a deletion within chromosome 22q11.2, which was confirmed by multiplex ligation-dependent probe amplification (MLPA).

CONCLUSIONThe QF-PCR assay developed in this study was a reliable and an efficient alterative approach to screen for 22q11 microdeletion in clinical diagnosis and genetic counseling.

Case-Control Studies ; Chromosome Deletion ; Chromosomes, Human, Pair 22 ; genetics ; Fluorescence ; Heart Defects, Congenital ; diagnosis ; genetics ; Humans ; Microsatellite Repeats ; Polymerase Chain Reaction ; instrumentation ; methods