Adenotonsillectomy in the context of obstructive sleep apnoea.

Adenotonsillectomy (T&A) is a common surgical procedure. Its frequency is highest in the paediatric age range and its most common current indication is obstructive sleep apnoea (OSA). Sleep studies are used to document the presence and severity of OSA.

Normalization and backscatter spectral analysis of human carotid arterial data acquired using a clinical linear array ultrasound imaging system.

The risk of plaque rupture in carotid atherosclerotic disease is associated more closely with the composition of plaque rather than the severity of stenosis. The constituents of plaque can be determined from ultrasonic spectral parameters obtained from normalized backscatter tissue data. Calibration of the data is done using echoes off a specular reflector which removes the system response of an ultrasound transducer, Terason (Teratech Corporation), from the backscatter data.

Macrophage responses to silica nanoparticles are highly conserved across particle sizes.

Concerns about the potential adverse health effects of engineered nanoparticles stems in part from the possibility that some materials display unique chemical and physical properties at nanoscales which could exacerbate their biological activity. However, studies that have assessed the effect of particle size across a comprehensive set of biological responses have not been reported. Using a macrophage cell model, we demonstrate that the ability of unopsonized amorphous silica particles to stimulate inflammatory protein secretion and induce macrophage cytotoxicity scales closely with the total administered particle surface area across a wide range of particle diameters (7-500 nm).

Identifying efficacious approaches to chemoprevention with chlorophyllin, purified chlorophylls and freeze-dried spinach in a mouse model of transplacental carcinogenesis.

The carcinogenic potential of dibenzo[a,l]pyrene (DBP) has been well characterized in numerous animal models. We have previously documented that a single dose of 15 mg/Kg DBP to pregnant mice late in gestation (GD 17) produces an aggressive T-cell lymphoma as well as lung and liver cancer in offspring. The current study examines the chemopreventative properties of chlorophyllin (CHL) and chlorophyll (Chl) in this transplacental carcinogenesis model.

Serotoninergic receptor 1A in the sudden infant death syndrome brainstem medulla and associations with clinical risk factors.

The immunoreactivity of the serotoninergic receptor subtype 1A (5HT(1A)R) was quantitatively analyzed in the human infant brainstem medulla (caudal and rostral levels). We hypothesized that immunoreactivity of 5HT(1A)R would be reduced in infants diagnosed with sudden infant death syndrome (SIDS). In particular that those infants with known clinical risk factors (including cigarette smoke exposure, bed sharing and sleep position) would have greater changes than those without clinical risks.

Selective dopamine D4 receptor agonist (A-412997) improves cognitive performance and stimulates motor activity without influencing reward-related behaviour in rat.

Current therapies for attention deficit hyperactivity disorder comprise psychostimulants, which block the dopamine transporter and/or stimulate the release of dopamine, leading to a global elevation in extrasynaptic dopamine. These drugs are, however, associated with a series of unwanted side effects such as insomnia, anorexia, headache, stomach problems and potential drug abuse. Recent evidence suggests that the dopamine D4 receptor may represent a selective dopamine target that could mediate cognitive as well as striatal motor processes.

Investigating the correspondence between transcriptomic and proteomic expression profiles using coupled cluster models.

Motivation: Modern transcriptomics and proteomics enable us to survey the expression of RNAs and proteins at large scales. While these data are usually generated and analyzed separately, there is an increasing interest in comparing and co-analyzing transcriptome and proteome expression data. A major open question is whether transcriptome and proteome expression is linked and how it is coordinated.

Modification of ilmenite surface chemistry for enhancing surfactants adsorption and bubble attachment.

In this study, microwave irradiation is used to modify ilmenite surface chemistry to enhance the adsorption of surfactants and the air bubble attachment. The results indicate that microwave irradiation can increase ilmenite flotation recovery by 20%. A positron emission particle tracking technique is used to study the dynamic behaviour of ilmenite particles in a Denver cell.

Evaluation of the pro-cognitive effects of the AMPA receptor positive modulator, 5-(1-piperidinylcarbonyl)-2,1,3-benzoxadiazole (CX691), in the rat.

Rationale: Positive allosteric modulators of the glutamatergic alpha-amino-3-hydroxy-5-methyl-4-isoazolepropionic acid (AMPA) receptor do not stimulate AMPA receptors directly but delay deactivation of the receptor and/or slow its desensitisation. This results in increased synaptic responses and enhanced long-term potentiation. Thus, it has been suggested that such compounds may have utility for the treatment of cognitive impairment.

Ultrasound monitoring of cartilaginous matrix evolution in degradable PEG hydrogels.

Ultrasound has potential as a non-destructive analytical technique to provide real-time online assessments of matrix evolution in cell-hydrogel constructs used in tissue engineering. In these studies, chondrocytes were encapsulated in poly(ethylene glycol) hydrogels, and gel degradation was manipulated to provide conditions with varying distribution of the large cartilage extracellular matrix molecule, collagen. Mechanical properties and matrix accumulations were simultaneously measured for each condition during 9.

Quantitative phosphoproteome analysis of lysophosphatidic acid induced chemotaxis applying dual-step (18)O labeling coupled with immobilized metal-ion affinity chromatography.

Reversible protein phosphorylation is a central cellular regulatory mechanism in modulating protein activity and propagating signals within cellular pathways and networks. Development of more effective methods for the simultaneous identification of phosphorylation sites and quantification of temporal changes in protein phosphorylation could provide important insights into molecular signaling mechanisms in various cellular processes. Here we present an integrated quantitative phosphoproteomics approach and its application for comparative analysis of Cos-7 cells in response to lysophosphatidic acid (LPA) gradient stimulation.

Are children just small adults? The differences between paediatric and adult sleep medicine.

Several important physiological and maturational changes occur in sleep development during the paediatric age range, particularly during infancy and in early childhood. As the pathology of sleep apnoea is superimposed onto a developing and often plastic physiological system, children often show a different pathophysiology to their adult counterparts. These factors need to be incorporated into the evaluation of a child's sleep problems.

Effects of directed gel degradation and collagenase digestion on the integration of neocartilage produced by chondrocytes encapsulated in hydrogel carriers.

Chondrocytes were encapsulated in non-degrading and partially degrading poly(ethylene glycol) (PEG) gels in apposition to native cartilage layers in order to examine the effects of gel degradation on the integration of regenerated cartilaginous matrix with native tissue. In addition, the effect of collagenase predigestion of the native cartilage surfaces on this integration was examined in studies with partially degrading co-polymer gels. Integration was quantitatively assessed by mechanical measurements of adhesive strength, and visualized by histological staining and non-destructive ultrasound analysis.

Interventions in the paediatric sleep laboratory: the use and titration of respiratory support therapies.

During sleep changes in central and peripheral neurological pathways and muscle tone result in unique vulnerabilities in the respiratory system. Abnormalities of the respiratory system that are not apparent in wakefulness can become evident during particular sleep states, making overnight polysomnography (PSG) a valuable diagnostic indicator of the source as well as the severity of the abnormality. In this review these respiratory disorders are grouped according to whether they are attributable to upper airway collapse, poor gas diffusion or inadequate ventilation (respiratory effort).

Brain-derived neurotrophic factor (BDNF) and TrkB in the piglet brainstem after post-natal nicotine and intermittent hypercapnic hypoxia.

Brain-derived neurotrophic factor (BDNF) and its receptor TrkB play a significant role in the regulation of cell growth, survival and death during central nervous system development. The expression of BDNF and TrkB is affected by noxious insults. Two insults during the early post-natal period that are of interest to our laboratory are exposure to nicotine and to intermittent hypercapnic hypoxia (IHH).

Effects of acute intermittent hypercapnic hypoxia on insulin sensitivity in piglets using euglycemic clamp.

Continuous hypoxia is associated with insulin resistance, altered glucose metabolism, and increased sympathetic nervous activity. This study examined the effect of 2 successive exposures to intermittent hypercapnic hypoxia (IHH) on glucose metabolism and insulin sensitivity in neonatal piglets. Piglets were assigned to 2 groups.

A cohort mortality study of chemical laboratory workers at Department of Energy Nuclear Plants.

Objective: This study evaluates the mortality experience of 6,157 chemical laboratory workers employed at United States Department of Energy facilities.

Methods: All cause, all cancer and cause-specific standardized mortality ratios were calculated. Cox regression analyses were conducted to further evaluate the relation between chemical exposure and mortality risk due to selected cancers.

Introduction to the special issue on diagnostic and therapeutic applications of ultrasound in bone--Part I.

The 13 papers and one item of correspondence in this special issue focus on diagnostic and therapeutic applications of ultrasound in bone. In Part I manuscripts discuss instrumentation, numerical modeling, applications, and guided waves.

A support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics.

Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry (MS/MS) studies. It would be advantageous, with respect to both accuracy and cost, to only search for those peptides that are detectable by MS (proteotypic).

Results: We present a support vector machine (SVM) model that uses a simple descriptor space based on 35 properties of amino acid content, charge, hydrophilicity and polarity for the quantitative prediction of proteotypic peptides.

Bone growth and turnover in progesterone receptor knockout mice.

The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and microcomputed tomography analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 wk of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR.

Experimental determination of phase velocity of perfluorocarbons: applications to targeted contrast agents.

Targeted acoustic contrast agents are designed to enhance the sensitivity and specificity of ultrasonic diagnoses. We have previously developed a ligand targeted ultrasonic contrast system that is a lipid-encapsulated, liquid-perfluorocarbon emulsion. The emulsion particles are small (250 nm) and have inherently low echogenicity unless bound to a surface by a pretargeted ligand through avidin-biotin interactions.

The identification of children with cleft palate and sleep disordered breathing using a referral system.

Background: Cleft palate is associated with an increased risk of sleep disordered breathing (SDB) but the magnitude of this risk and specific risk factors are unclear. A better understanding of these components of risk will aid the early identification of SDB in this group of children.

Objective: To describe the clinical characteristics and results of sleep studies undertaken in a cohort of children with cleft palate.

The mammary epithelial cell secretome and its regulation by signal transduction pathways.

Extracellular proteins released by mammary epithelial cells are critical mediators of cell communication, proliferation, and organization, yet the actual spectrum of proteins released by any given cell (the secretome) is poorly characterized. To define the set of proteins secreted by human mammary epithelial cells (HMEC), we combined analytical and computational approaches to define a secretome protein set based upon probable biological significance. Analysis of HMEC-conditioned medium by liquid chromatography-mass spectrometry resulted in identification of 889 unique proteins, of which 151 were found to be specifically enriched in the extracellular compartment when compared with a database of proteins expressed in whole HMEC lysates.

Tissue fixation effects on immunohistochemical staining of caspase-3 in brain tissue.

Fixation methods for tissue often vary amongst clinical and research laboratories. To evaluate the effects of fixation method on studies of brain tissue, we examined immunohistochemical outcomes amongst 2 fixatives, 4 caspase-3 antibodies, and 2 species (human infants and piglets). Fixatives were 10% neutral buffered formalin (NBF) or 10% NBF and glacial acetic acid (FAA).

Neuronal cell death in the Sudden Infant Death Syndrome brainstem and associations with risk factors.

Immunoreactive expression of three cell death markers was quantitatively analysed in the human infant brainstem medulla. We assessed active caspase-3, TUNEL and single-stranded DNA (ssDNA) in a cohort of 92 infants, and analysed for: (i) variations in the immunoreactive expression with development; (ii) comparison of infants diagnosed with the Sudden Infant Death Syndrome (SIDS, n = 67) to infants who died suddenly with another diagnosis (non-SIDS, n = 25); and (iii) correlations with known clinical risk factors for SIDS. Five nuclei from the brainstem medulla (caudal and rostral levels) were studied, including the hypoglossal (XII), dorsal motor nucleus of the vagus (DMNV), the dorsal column nuclei (gracile and cuneate) and the arcuate nucleus.