Molecular characterization of three novel chemokine receptors in rainbow trout (Oncorhynchus mykiss).

Chemokines signal through a family of seven-transmembrane domain G-coupled receptors in order to regulate both leukocyte mobilization and activate the recruited cells. Although many chemokines have been identified in rainbow trout (Oncorhynchus mykiss), only a few chemokine receptors have been reported to date. In this work, we have cloned three novel chemokine receptors in rainbow trout. One of these receptors seems to be a clear orthologue of CCR6, while the second one constitutes a novel CCR9 gene different from the previous CCR9 reported in this species. This gene, which we have designated as CCR9B, represents another lineage of fish CCR9 genes, not previously identified. Finally, a deeper phylogenetic analysis of the third novel chemokine receptor gene, which had been identified on the basis of sequence similarity to CCR3, constitutes a novel lineage of CCR receptors which has no equivalent in humans and that may be teleost-specific. We have designated this novel gene as CCR13, to avoid any possible ascription to mammalian genes. Further transcriptional studies revealed that CCR6 was constitutively transcribed in thymus, gills, hindgut and peripheral blood leukocytes (PBLs), while CCR9B was strongly transcribed in thymus and PBLs but also in spleen, gills, hindgut and brain at lower levels. CCR13, on the other hand, was strongly detected in spleen, head kidney and PBLs and faintly in thymus, gills, brain and gonad. The data provided constitutes a step forward the identification of novel chemokine receptors that may contribute to a future understanding of chemokine signalling in fish.

Local allergic rhinitis in children: Clinical characteristics and role of basophil activation test as a diagnostic tool.

BACKGROUND: Local allergic rhinitis (LAR) is a condition involving a localized nasal allergic response in absence of systemic atopy. Most studies on LAR have been performed in adults. We aimed to describe clinical characteristics of LAR pediatric patients, its clinical evolution over a 7-year follow-up period and to study the role of basophil activation test (BAT), for its diagnosis. METHODS: Forty-four children with non-allergic rhinitis (NAR) were included (24 males, 20 females, aged under 15 years). Nasal allergen provocation test (NAPT) and BAT were performed with Dermatophagoides pteronyssinus and Phleum pratense. RESULTS: Seven patients (16%) were diagnosed of LAR. Six reacted to D pteronyssinus and one to P pratense. All LAR and 86% of NAR patients presented perennial symptoms. Fifty-seven percent of NAR and LAR patients referred persistent symptoms. Around half of NAR and LAR patients reported mild-moderate clinical manifestations. Three LAR patients associated conjunctival symptoms, proportionally more than NAR patients (19%, 7 out of 37). NAR patients presented bronchial asthma (n = 10) more frequently than LAR children (n = 1). More than half of LAR and NAR patients presented family history of atopy. BAT was negative in all LAR patients. On follow-up, 3 LAR patients and 10 of the 25 NAR patients who agreed to be retested, presented systemic sensitization. Dust mites were the most frequent allergen involved. CONCLUSIONS: LAR should be ruled out in children with NAR. Almost half of children with LAR develop systemic sensitization over time. BAT shows low sensitivity for the diagnosis of LAR in children.

Spatiotemporal pattern of glucose in a microfluidic device depend on the porosity and permeability of the medium: A finite element study.

BACKGROUND: Glucose plays an important role as a source of nutrients and influence cellular processes such as differentiation, proliferation and migration. In vitro models based on microfluidic devices represent an alternative to study several biological processes in a more reproducible and controllable method compared to in vivo models. Glucose concentration across a microfluidic chip and its behavior in experimental conditions is not completely understood. OBJECTIVE: This paper investigated the spatiotemporal distribution of glucose across the hydrogel inside a microfluidic chip. The influence of different parameters, boundary and initial conditions of experiments on glucose concentration was studied. METHODS: A finite element model using a two dimensional geometry was developed. With this model, patterns of glucose concentration were investigated for different combinations of flow rate of culture medium, permeability and porosity of the medium. Patterns were also studied for two hydrogels made of collagen type I and fibrin with different initial and boundary conditions for pressure and glucose concentration. RESULTS: Porosity influenced significantly on the chemical gradients generated when interstitial fluid flow was null or neglectable. A difference in concentration lower than 15% was obtained at the input of microchamber and after 90 min, when porosity changed from 0.5 to 0.99. In addition, no significant effects of modifications in permeability were observed. Regarding the collagen and fibrin matrices, in the presence of a pressure gradient of 40 Pa, the permeability significantly influenced on the concentration gradients generated. CONCLUSIONS: Porosity influences importantly on patterns when diffusion is the main transport mechanism. Permeability is the most influencing parameter when a fluid flow is present. Common insertion rates of culture medium does not significantly modify the patterns of glucose inside the chips. Thus, new experiments must consider the impact of such parameters on the distribution and the time span that nutrients occupy the medium. To better contribute with experimental trials, other studies involving cell-cell and cell-extracellular matrix interactions, and different chip geometries should be developed. The results of the present work could assist to develop specific systems for experimentation, to design new experiments and to improve the analysis of the obtained results.

Effect of high-intensity ultrasound on the technofunctional properties and structure of jackfruit (Artocarpus heterophyllus) seed protein isolate.

The influence of high-intensity ultrasound (HIU) on the technofunctional properties and structure of jackfruit seed protein isolate (JSPI) was investigated. Protein solutions (10%, w/v) were sonicated for 15min at 20kHz to the following levels of power output: 200, 400, and 600W (pulse duration: on-time, 5s; off-time 1s). Compared with untreated JSPI, HIU at 200W and 400W improved the oil holding capacity (OHC) and emulsifying capacity (EC), but the emulsifying activity (EA) and emulsion stability (ES) increased at 400W and 600W. The foaming capacity (FC) increased after all HIU treatments, as opposed to the water holding capacity (WHC), least gelation concentration (LGC), and foaming stability (FS), which all decreased except at pH 4 for FS. Tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (Tricine-SDS-PAGE) showed changes in the molecular weight of protein fractions after HIU treatment. Scanning electron microscopy (SEM) demonstrated that HIU disrupted the microstructure of JSPI, exhibiting larger aggregates. Surface hydrophobicity and protein solubility of the JSPI dispersions were enhanced after ultrasonication, which increased the destruction of internal hydrophobic interactions of protein molecules and accelerated the molecular motion of proteins to cause protein aggregation. These changes in the technofunctional and structural properties of JSPI could meet the complex needs of manufactured food products.

Correlation between oxyhaemoglobin saturation by pulse oximetry and partial pressure of oxygen in patients with acute respiratory failure. / Correlación entre la saturación de oxihemoglobina por pulsioximetría y la presión arterial de oxígeno en pacientes con insuficiencia respiratoria aguda.

OBJECTIVES: To ascertain the correlation between the partial pressure of oxygen (PaO2) and oxyhaemoglobin saturation by pulse oximetry (SpO2) in patients who were admitted to the emergency department with suspected acute respiratory failure. MATERIAL AND METHODS: A prospective, observational multicentre study was conducted in the emergency departments of 3 Spanish hospitals. RESULTS: The study included 166 patients who presented mean±standard deviation PaO2, SpO2 and fraction of inspired oxygen (FiO2) values of 61.64±17.3mmHg, 87.61±8.8% and 0.28±0.15%, respectively. The median PaO2/FiO2 and SpO2/FiO2 ratios were 256.6 and 359.2, respectively. The correlation between PaO2/FiO2 and the SpO2/FiO2 was 0.745 (P<.001). CONCLUSIONS: The SpO2/FiO2 ratio can be used to calculate PaO2/FiO2 and determine the oxygenation state of patients with acute respiratory failure.

Evaluation of residual stresses due to bone callus growth: a computational study.

Mechanical environment in callus is determinant for the evolution of bone healing. However, recent mechanobiological computational works have underestimated the effect that growth exerts on the mechanical environment of callus. In the present work, we computationally evaluate the significance of growth-induced stresses, commonly called residual stresses, in callus. We construct a mechanobiological model of a callus in the metatarsus of a sheep in two different stages: one week and four weeks after fracture. The magnitude of stresses generated during callus growth is compared with the magnitude of stresses when only external loads are applied to the callus. We predict that residual stresses are relevant in some areas, mainly located at the periosteal side far from the fracture gap. Therefore, the inclusion of these residual stresses could represent a significant impact on the callus growth and predict a different evolution of biological processes occurring during bone healing.

[Beneficial effects of chocolate on cardiovascular health]. / Efectos beneficiosos del chocolate en la salud cardiovascular.

Since ancient times, numerous health beneficial effects have been attributed to chocolate, closing up its consumption to a therapeutic use. The present study reviews some relevant studies about chocolate (and its bioactive compounds) on some cardiovascular risk factors and stresses the need of future studies. The consumption of cocoa/ chocolate (i) increases plasma antioxidant capacity, (ii) diminishes platelet function and inflammation, and (iii) decreases diastolic and systolic arterial pressures. Data currently available indicate that daily consumption of cocoa-rich chocolate (rich in polyphenols) may at least partially lower cardiovascular disease risk. Further studies are required in order to establish the bioavailability and mechanisms of action of bioactive compounds in chocolate. The study of the interaction of chocolate and its components with candidate genes will also supply necessary information regarding the individuals best suited to benefit from a potential cardiovascular disease treatment with chocolate.

Monitoring in vivo load transmission through an external fixator.

This work presents a portable non-invasive external fixator to assess and monitor fracture healing in real time. To evaluate the potential of this fixator, a transverse osteotomy was performed in the tibia of six adult sheep (mean age 3+/-0.5 years and weight 63+/-5 kg). The fractures were stabilized by a specially designed unilateral external fixator, which was instrumented by means of a set of strain gauges. Strains in the external surface of the fixator were monitored during all the healing process. A wireless, remote monitoring of the implant was developed through a specially designed external telemetric device. The strain gauges were arranged in two different half-bridge Wheatstone configurations, allowing easy post-processing of the signal. Thus, bending loads were measured in two planes of the external fixator acting as a load cell. The load through the fixator was evaluated for the gait cycle during all the healing process. Full weight bearing of the injured leg was observed from the beginning. The load transmission mechanism in the fixator was quite similar in all operated tibias and radiographic images showed a successful healing in all animals. Although the fixator has only been tested in an animal model, after further testing this system may have clinical potential.

Influence of the frequency of the external mechanical stimulus on bone healing: a computational study.

The mechanical environment considerably affects the evolution of the bone healing process. However, the effect of an external cyclic stimulation on the process has not yet been fully clarified. The aim of the present work is to evaluate the distribution of different mechanical variables in the fracture callus when an external cyclic stimulation is applied at different frequencies, in order to investigate those stimuli most likely to regulate bone healing. To perform this analysis an axisymmetric poroelastic finite element model of a sheep metatarsus fracture has been developed and several mechanical variables quantified within the callus: deviatoric strain, octahedral strain, pore pressure and fluid flow velocity. The applied mechanical stimulus corresponds to a compression displacement of 0.02 mm at frequencies of 1, 50 and 100Hz. The fluid flow velocity experiences considerable variations in amplitude and peak value when the frequency of the external stimulus changes, while the rest of the mechanical variables are not significatively modified. We conclude that the change in the frequency of the external mechanical stimulus directly affects the interstitial fluid flow velocity in the fracture callus. This change in the fluid flow velocity may induce movement of wastes, feeds or growth factors, as well as stimulating cellular differentiation and proliferation by means of changes in the mechanical environment of the callus. In addition, the results of this work suggest that, to obtain a more significant effect of cyclic stimulation, higher frequencies with lower amplitude than those normally used in previous experimental works are needed.