Vitamin D receptor (VDR) polymorphisms and severe RSV bronchiolitis: a systematic review and meta-analysis.

Background: A number of small studies have suggested a relationship between vitamin D status and severe acute lower respiratory tract infection (ALRI), including RSV-bronchiolitis. The objective of this study was to evaluate the relationship between vitamin D receptor (VDR) polymorphism and severe RSV-bronchiolitis through a systemic literature review and meta-analysis.

Methods: A comprehensive electronic literature search was conducted to identify all studies published before January 2013.

Ethics application protocols for multicentre clinical studies in Canada: A paediatric rheumatology experience.

Introduction: Individual institutions govern research ethics applications and each must administer and regulate their own protocols. Variations in ethics review procedures and expectations among centres impose impediments to efficiently conducting multicentre studies.

Methods: Observations relating to preparing multisite ethics documents for a study conducted by Canadian paediatric rheumatology investigators are described.

Use of monocyte/endothelial cell co-cultures (in vitro) and a subcutaneous implant mouse model (in vivo) to evaluate a degradable polar hydrophobic ionic polyurethane.

Potential benefits of co-culturing monocytes (MC) with vascular smooth muscle cells have been reported on for tissue engineering applications with a degradable, polar, hydrophobic, and ionic polyurethane (D-PHI). Since the interaction of MC and endothelial cells (EC) within the blood vessel endothelium is also a process of wound repair it was of interest to investigate their function when cultured on the synthetic D-PHI materials, prior to considering the materials' use in vascular engineering. The co-culture (MC/EC) in vitro studies were carried out on films in 96 well plates and porous scaffold disks were prepared for implant studies in an in vivo subcutaneous mouse model.

Vitamin D deficiency in young children with severe acute lower respiratory infection.

Rationale: Acute lower respiratory infection (ALRI) is one of the most common reasons for hospitalization and intensive care unit admission among children. Season related decreases in the immunomodulatory molecule, vitamin D, remain an unexplored factor that might contribute to the increased occurrence of ALRI in children.

Objective: To investigate a possible association between vitamin D deficiency and respiratory infection by comparing serum 25 hydroxyvitamin D [25(OH)D] levels in a group of young children with ALRI to an age-matched group without respiratory infection.

Effect of polyurethane chemistry and protein coating on monocyte differentiation towards a wound healing phenotype macrophage.

Tissue regeneration alternatives for peripheral vascular disease are actively being investigated; however, few studies in this area have probed the role of the wound healing monocyte-derived macrophage (MDM). Inflammatory MDMs transition to wound healing MDMs as the relative levels of tumor necrosis factor-alpha (TNF-alpha) decrease and IL-10 increase. TNF-alpha has been linked to the regulation of HMGB1 (high mobility group box 1 protein), a nuclear protein that upon macrophage stimulation can be secreted and act as a pro-inflammatory cytokine.

The effects of phorbol ester activation and reactive oxygen species scavengers on the macrophage-mediated foreign body reaction to polyurethanes.

Phorbol myristate acetate, a protein kinase C activator, inhibited monocyte-derived macrophage (MDM)-mediated degradation of aliphatic (HDI) polycarbonate-based polyurethanes but not degradation of the aromatic polycarbonate-based polyurethane (MDI). The objectives of this study were to determine if reactive oxygen species are involved in the phorbol myristate acetate effect on esterase activity and MDM-mediated polycarbonate-based polyurethane degradation and to find a good marker of material-initiated activation of MDM. The phorbol myristate acetate-dependent effects of the material chemistry on cell activation and degradation were evaluated by adding reactive oxygen species scavengers, catalase plus superoxide dismutase to MDM and assaying possible markers of MDM activation: esterase activity, acid phosphatase activity, and high molecular weight group box 1 protein (HMGB1).

Efficient mitochondrial targeting relies on co-operation of multiple protein signals in plants.

To date, the most prevalent model for transport of pre-proteins to plant mitochondria is based on the activity of an N-terminal extension serving as a targeting peptide. Whether the efficient delivery of proteins to mitochondria is based exclusively on the action of the N-terminal extension or also on that of other protein determinants has yet to be defined. A novel mechanism is reported here for the targeting of a plant protein, named MITS1, to mitochondria.

Epidemiologic considerations in unexplained pediatric arthralgia: the role of season, school, and stress.

Objective: To determine demographic and epidemiologic characteristics in children with unexplained joint pain.

Methods: The study population included 730 children (< 18 yrs of age) referred between 1981 and 2007 to the Saskatchewan Pediatric Rheumatology Program, University of Saskatchewan, because of arthralgia. Parents and patients completed a questionnaire at the time of initial presentation, and a diagnosis of unexplained arthralgia was assigned based on clinical assessment.

Dynamic organization of COPII coat proteins at endoplasmic reticulum export sites in plant cells.

Protein export from the endoplasmic reticulum (ER) is mediated by the accumulation of COPII proteins such as Sar1, Sec23/24 and Sec13/31 at specialized ER export sites (ERES). Although the distribution of COPII components in mammalian and yeast systems is established, a unified model of ERES dynamics has yet to be presented in plants. To investigate this, we have followed the dynamics of fluorescent fusions to inner and outer components of the coat, AtSec24 and AtSec13, in three different plant model systems: tobacco and Arabidopsis leaf epidermis, as well as tobacco BY-2 suspension cells.

Capillary blood sampling as an alternative to venipuncture in the assessment of serum 25 hydroxyvitamin D levels.

This study compared 25-hydroxyvitamin D [25(OH)D] measurements in capillary and venous blood samples collected, respectively by fingerprick and venipuncture. Capillary blood for measuring 25(OH)D has potential advantages by reducing blood volume required (2mL versus 0.3mL for venipuncture and capillary sampling, respectively), facilitating blood collection for those populations in whom venipuncture is difficult (e.

Assessment of sample collection and storage methods for multicenter immunologic research in children.

Multicenter studies involving both large and small centers separated by significant distances pose unique challenges to biological sample collection. The objective of this study was to evaluate protocols for determining inflammatory biomarkers that are cost and manpower efficient for handling blood destined for a sample repository. Tempus (Applied Biosystems) and Paxgene (Qiagen) blood collection systems were evaluated for RNA isolation.

Plant Sar1 isoforms with near-identical protein sequences exhibit different localisations and effects on secretion.

In plants, differentiation of subdomains of the endoplasmic reticulum (ER) dedicated to protein export, the ER export sites (ERES), is influenced by the type of export-competent membrane cargo to be delivered to the Golgi. This raises a fundamental biological question: is the formation of transport intermediates at the ER for trafficking to the Golgi always regulated in the same manner? To test this, we followed the distribution and activity of two plant Sar1 isoforms. Sar1 is the small GTPase that regulates assembly of COPII (coat protein complex II) on carriers that transport secretory cargo from ER to Golgi.

Correct targeting of plant ARF GTPases relies on distinct protein domains.

Indispensable membrane trafficking events depend on the activity of conserved small guanosine triphosphatases (GTPases), anchored to individual organelle membranes. In plant cells, it is currently unknown how these proteins reach their correct target membranes and interact with their effectors. To address these important biological questions, we studied two members of the ADP ribosylation factor (ARF) GTPase family, ARF1 and ARFB, which are membrane anchored through the same N-terminal myristoyl group but to different target membranes.

Studying protein export from the endoplasmic reticulum in plants.

Understanding the mechanisms of protein sorting and targeting through the plant secretory pathway has become the focus of many research laboratories. The development of a model system whereby recombinant genes can be transiently expressed in protoplasts has facilitated the study of protein transport signals. Experimental strategies combining a protoplast expression system with endoglycosidase H, vacuole purification, and pulse-chase analyses are used to investigate aspects of specific proteins as they pass through the secretory system.

Is cell culture stressful? Effects of degradable and nondegradable culture surfaces on U937 cell function.

In vitro cell culture has become one of the most widely used techniques in biological and health sciences research, with the most common culture supports being either tissue culture grade polystyrene (TCPS) or polydimethylsiloxane (PDMS). It has previously been shown that monocyte-derived macrophages (MDMs) respond to material surface chemistry, synthesizing and releasing degradative activities that could produce products, which alter the cell's response. In this study, functional parameters of differentiated U937 macrophage-like cells were compared when cultured on nondegradable standard control surfaces versus models of biomaterials (polycarbonate-based polyurethanes) used in the manufacture of medical devices previously shown to degrade and/or elicit pathways of inflammation.

Post-Golgi protein traffic in the plant secretory pathway.

The Golgi apparatus in plants is organized as a multitude of individual stacks that are motile in the cytoplasm and in close association with the endoplasmic reticulum (ER) (Boevink et al. in Plant J 15:441-447, 1998). These stacks operate as a sorting centre for cargo molecules, providing modification and redirection to other organelles as appropriate.

De novo formation of plant endoplasmic reticulum export sites is membrane cargo induced and signal mediated.

The plant endoplasmic reticulum (ER) contains functionally distinct subdomains at which cargo molecules are packed into transport carriers. To study these ER export sites (ERES), we used tobacco (Nicotiana tabacum) leaf epidermis as a model system and tested whether increased cargo dosage leads to their de novo formation. We have followed the subcellular distribution of the known ERES marker based on a yellow fluorescent protein (YFP) fusion of the Sec24 COPII coat component (YFP-Sec24), which, differently from the previously described ERES marker, tobacco Sar1-YFP, is visibly recruited at ERES in both the presence and absence of overexpressed membrane cargo.

Multiple roles of ADP-ribosylation factor 1 in plant cells include spatially regulated recruitment of coatomer and elements of the Golgi matrix.

Recent evidence indicates that ADP-ribosylation factor 1 (ARF1) carries out multiple roles in plant cells that may be independent from the established effector complex COPI. To investigate potential COPI-independent functions, we have followed the dynamics of ARF1 and a novel putative effector, the plant golgin GRIP-related ARF-binding domain-containing Arabidopsis (Arabidopsis thaliana) protein 1 (GDAP1) in living plant cells. We present data that ascribe a new role to ARF1 in plant cell membrane traffic by showing that the GTPase functions to recruit GDAP1 to membranes.

Differential effects of uniaxial and biaxial strain on U937 macrophage-like cell morphology: influence of extracellular matrix type proteins.

Tissue engineering concepts have expanded in the last decade to consider the importance of biochemical signaling from extracellular matrix (ECM) proteins adhered to substrates such as polymeric and ceramic scaffolds. This study investigated combined ECM/mechanical factors on the key signaling cells (macrophages) for wound healing, since previously, mechanical strain and ECM proteins have only been considered separately for their effects on macrophage morphology. Human U937 macrophage-like cells were cultured on a model elastomeric membrane, coated with either collagen type I or poly-RGD peptide (ProNectin).

The functional response of U937 macrophage-like cells is modulated by extracellular matrix proteins and mechanical strain.

Extracellular matrix proteins (ECMs) play a significant role in the transfer of mechanical strain to monocyte-derived macrophages (MDMs) affecting morphological changes in a foreign body reaction. This study investigated how the functional responses of U937 macrophage-like cells differed when subjected to 2 dynamic strain types (nonuniform biaxial or uniform uniaxial strain) while cultured on siloxane membranes coated with either collagen type I or RGD peptide repeats (ProNectin). Biaxial strain caused an increase in intracellular esterase and acid phosphatase (AP) activities, as well as monocyte-specific esterase (MSE) protein levels in cells that were seeded on either uncoated surfaces (shown previously) or collagen, but not ProNectin.

Traffic between the plant endoplasmic reticulum and Golgi apparatus: to the Golgi and beyond.

Significant advances have been made in recent years that have increased our understanding of the trafficking to and from membranes that are functionally linked to the Golgi apparatus in plants. New routes from the Golgi to organelles outside the secretory pathway are now being identified, revealing the importance of the Golgi apparatus as a major sorting station in the plant cell. This review discusses our current perception of Golgi structure and organization as well as the molecular mechanisms that direct traffic in and out of the Golgi.

Seeking a way out: export of proteins from the plant endoplasmic reticulum.

The functionality of the secretory pathway relies on the efficient transfer of cargo molecules from their site of synthesis in the endoplasmic reticulum (ER) to successive compartments within the pathway. Although transport mechanisms of secretory proteins have been studied in detail in various non-plant systems, it is only recently that our knowledge of secretory routes in plants has expanded dramatically. This review focuses on exciting new findings concerning the exit mechanisms of cargo proteins from the plant ER and the role of ER export sites in this process.

Polycarbonate-urethane hard segment type influences esterase substrate specificity for human-macrophage-mediated biodegradation.

Previous studies have shown that esterase activity can degrade a variety of polyurethanes (PUs), including polycarbonate-based PUs (PCNUs). When cultured on PCNUs, differing in their chemistries, monocyte-derived macrophages (MDM) synthesized and secreted different amounts of both cholesterol esterase (CE) and monocyte-specific esterase (MSE). MDM were seeded on PCNUs synthesized with hexane diisocyanate (HDI) or 4,4'-methylene-bis-phenyl diisocyanate (MDI), PCN and [14C]butanediol (BD) in the ratio 3:2:1 (referred to as HDI321 or MDI321).

Cyclic biaxial strain affects U937 macrophage-like morphology and enzymatic activities.

As monocytes migrate to the site of a foreign body and differentiate into mature monocyte-derived macrophages (MDMs), the cells undergo a morphological transformation that involves mechanical stimulation via membrane stretch. Because the site of many cardiovascular implant devices includes substrates that are also undergoing mechanical change, it is of interest to assess the effect of such dynamic conditions on cellular-biomaterial responses. This study investigated the influence of cyclic (0.

Characterization of the Flexcell Uniflex cyclic strain culture system with U937 macrophage-like cells.

Mechanical forces alter many cell functions in a variety of cell types. It has been recognized that stimulation of cells in culture may be more representative of some physiologic conditions. Although there are commercially available systems for the study of cells cultured in a mechanical environment, very little has been documented on the validation techniques for these devices.