166 research outputs found

    Alveolar fluid in acute respiratory distress syndrome promotes fibroblast migration: role of platelet-derived growth factor pathway

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    OBJECTIVES: Fibroblast migration is an initiating step in fibroproliferation; its involvement during acute lung injury and acute respiratory distress syndrome remains poorly understood. The aims of this study were: 1) to determine whether bronchoalveolar lavage fluids from patients with acute lung injury/acute respiratory distress syndrome modulate lung fibroblast migration; 2) to assess lung fibroblast migration\u27s clinical relevance; and 3) to evaluate the role of the platelet-derived growth factor pathway in this effect. DESIGN: Prospective cohort study. SETTING: Three intensive care units of a large tertiary referral center. PATIENTS: Ninety-three ventilated patients requiring bronchoalveolar lavage fluids were enrolled (48 with acute respiratory distress syndrome, 33 with acute lung injury, and 12 ventilated patients without acute lung injury/acute respiratory distress syndrome). INTERVENTIONS: After bronchoalveolar lavage fluids collection during standard care, the patients were followed up for 28 days and clinical outcomes were recorded. Migration assays were performed by using a Transwell model; bronchoalveolar lavage fluids platelet-derived growth factor and soluble platelet-derived growth factor receptor-alpha were characterized by Western blot and measured by ELISA. MEASUREMENTS AND MAIN RESULTS: Most of the bronchoalveolar lavage fluids inhibited basal fibroblast migration. Bronchoalveolar lavage fluids chemotactic index increased with severity of lung injury (28% in patients without acute lung injury/acute respiratory distress syndrome and with acute lung injury vs. 91% in acute respiratory distress syndrome patients; p = .016). In acute lung injury/acute respiratory distress syndrome patients, inhibition of basal fibroblast migration by bronchoalveolar lavage fluids below 52% was independently associated with a lower 28-day mortality (odds ratio [95% confidence interval] 0.313 [0.10-0.98], p = .046). Platelet-derived growth factor-related peptides and soluble platelet-derived growth factor-Ralpha were detected in all bronchoalveolar lavage fluids from acute lung injury/acute respiratory distress syndrome patients. The effect of bronchoalveolar lavage fluids stimulating migration was inhibited by a specific platelet-derived growth factor receptor inhibitor (AG1296). Bronchoalveolar lavage fluids inhibiting migration reversed the effect of rh-platelet-derived growth factor-BB and reduced by 40% the binding of 125I-platelet-derived growth factor-BB to fibroblast cell surface in favor of a role for platelet-derived growth factor-sRalpha. CONCLUSIONS: : Together, our results suggest that during acute lung injury, fibroblast migration is modulated by bronchoalveolar lavage fluids through a platelet-derived growth factor/platelet-derived growth factor-sRalpha balance. Migration is associated with clinical severity and patient 28-day mortality

    Phenotypic cha- racterization of pig genetic resources in the departments of Oueme and Plateau in Benin

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    L’élevage porcin est très pratiqué au Sud-Bénin et implique une diversité de races ou de populations. L’objectif de l’étude était de caractériser les différents porcs sur le plan morphométrique et phénotypique. Ainsi, les données phéno- typiques ont été collectées sur 149 porcs, dont 14 améliorés, 91 croisés et 44 locaux. Les porcs de type génétique local ont présenté des mesures morpho- logiques significativement inférieures (p < 0,05) à celles des porcs améliorés et des animaux issus des croisements entre les porcs améliorés et les porcs locaux. Les poils des porcs locaux étaient significativement plus courts (p < 0,05) que ceux des porcs améliorés et des croisés. La couleur de la robe a varié d’un type génétique à l’autre. La couleur la plus rencontrée a été le blanc uniforme, suivi du noir uniforme chez tous les types génétiques. Le profil de la tête était plus rectiligne chez les porcs locaux, et plus concave chez les porcs améliorés et chez les croisés. Les oreilles dressées étaient moins observées chez les croisés. Elles étaient orientées vers l’avant chez les porcs améliorés et chez les croisés alors qu’elles étaient dressées et orientées vers l’arrière chez les porcs locaux. La queue en tire-bouchon a été significativement (p < 0,05) plus présente chez les porcs améliorés que chez les porcs croisés, et elle a été plus présente chez ces derniers que chez les porcs locaux. La ligne dorsale droite a été davantage observée chez les porcs locaux et chez les croisés que chez les porcs amélio- rés chez lesquels la ligne était plus creuse. Les porcs croisés ont présenté une grande similarité avec les porcs améliorés

    Pilot Anopheles gambiae full-length cDNA study: sequencing and initial characterization of 35,575 clones

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    We describe the preliminary analysis of over 35,000 clones from a full-length enriched cDNA library from the malaria mosquito vector Anopheles gambiae. The clones define nearly 3,700 genes, of which around 2,600 significantly improve current gene definitions. An additional 17% of the genes were not previously annotated, suggesting that an equal percentage may be missing from the current Anopheles genome annotation

    Thin-film transducers for the detection and imaging of Brillouin oscillations in transmission on cultured cells

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    Mechanical imaging and characterisation of biological cells has been a subject of interest for the last twenty years. Ultrasonic imaging based on the scanning acoustic microscope (SAM) and mechanical probing have been extensively reported. Large acoustic attenuation at high frequencies and the use of conventional piezo-electric transducers limit the operational frequency of a SAM. This limitation results in lower resolution compared to an optical microscope. Direct mechanical probing in the form of applied stress by contacting probes causes stress to cells and exhibits poor depth resolution. More recently, laser ultrasound has been reported to detect ultrasound in the GHz range via Brillouin oscillations on biological cells. This technique offers a promising new high resolution acoustic cell imaging technique. In this work, we propose, design and apply a thin-film based opto-acoustic transducer for the detection in transmission of Brillouin oscillations on cells. The transducer is used to generate acoustic waves, protect the cells from laser radiation and enhance signal-to-noise ratio (SNR). Experimental traces are presented in water films as well as images of the Brillouin frequency of phantom and fixed 3T3 fibroblast cells

    Drug delivery to tumours using a novel 5-FU derivative encapsulated into lipid nanocapsules

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    In this work, a novel lipophilic 5-fluorouracil (5-FU) derivative was synthesised and encapsulated into lipid nanocapsules (LNC). 5-FU was modified with lauric acid to give a lipophilic mono-lauroyl-derivative (5-FU-C12, MW of about 342 g/mol, yield of reaction 70%). 5-FU-C12 obtained was efficiently encapsulated into LNC (encapsulation efficiency above 90%) without altering the physico-chemical characteristics of LNC. The encapsulation of 5-FU-C12 led to an increased stability of the drug when in contact with plasma being the drug detectable until 3 h following incubation. Cytotoxicity assay carried out using MTS on 2D cell culture showed that 5-FU-C12-loaded LNC had an enhanced cytotoxic effect on glioma (9L) and human colorectal (HTC-116) cancer cell line in comparison with 5-FU or 5-FU-C12. Then, HCT-116 tumour spheroids were cultivated and the reduction of spheroid volume was measured following treatment with drug-loaded LNC and drugs alone. Similar reduction on spheroids volume was observed following the treatment with drug-loaded LNC, 5-FU-C12 and 5-FU alone, while blank LNC displayed a reduction in cell viability only at high concentration. Globally, our data suggest that the encapsulation increased the activity of the 5-FU-C12. However, in-depth evaluations of LNC permeability into spheroids are needed to disclose the potential of these nanosystems for cancer treatment

    Interleukin 6, lipopolysaccharide-binding protein and interleukin 10 in the prediction of risk and etiologic patterns in patients with community-acquired pneumonia: results from the German competence network CAPNETZ

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    <p>Abstract</p> <p>Background</p> <p>The aim of our study was to investigate the predictive value of the biomarkers interleukin 6 (IL-6), interleukin 10 (IL-10) and lipopolysaccharide-binding protein (LBP) compared with clinical CRB and CRB-65 severity scores in patients with community-acquired pneumonia (CAP).</p> <p>Methods</p> <p>Samples and data were obtained from patients enrolled into the German CAPNETZ study group. Samples (blood, sputum and urine) were collected within 24 h of first presentation and inclusion in the CAPNETZ study, and CRB and CRB-65 scores were determined for all patients at the time of enrollment. The combined end point representative of a severe course of CAP was defined as mechanical ventilation, intensive care unit treatment and/or death within 30 days. Overall, a total of 1,000 patients were enrolled in the study. A severe course of CAP was observed in 105 (10.5%) patients.</p> <p>Results</p> <p>The highest IL-6, IL-10 and LBP concentrations were found in patients with CRB-65 scores of 3-4 or CRB scores of 2-3. IL-6 and LBP levels on enrollment in the study were significantly higher for patients with a severe course of CAP than for those who did not have severe CAP. In receiver operating characteristic analyses, the area under the curve values for of IL-6 (0.689), IL-10 (0.665) and LPB (0.624) in a severe course of CAP were lower than that of CRB-65 (0.764) and similar to that of CRB (0.69). The accuracy of both CRB and CRB-65 was increased significantly by including IL-6 measurements. In addition, higher cytokine concentrations were found in patients with typical bacterial infections compared with patients with atypical or viral infections and those with infection of unknown etiology. LBP showed the highest discriminatory power with respect to the etiology of infection.</p> <p>Conclusions</p> <p>IL-6, IL-10 and LBP concentrations were increased in patients with a CRB-65 score of 3-4 and a severe course of CAP. The concentrations of IL-6 and IL-10 reflected the severity of disease in patients with CAP. The predictive power of IL-6, IL-10 and LBP for a severe course of pneumonia was lower than that of CRB-65. Typical bacterial pathogens induced the highest LBP, IL-6 and IL-10 concentrations.</p

    Relating circulating thyroid hormone concentrations to serum interleukins-6 and -10 in association with non-thyroidal illnesses including chronic renal insufficiency

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    <p>Abstract</p> <p>Background</p> <p>Because of the possible role of cytokines including interleukins (IL) in systemic non-thyroidal illnesses' (NTI) pathogenesis and consequently the frequently associated alterations in thyroid hormone (TH) concentrations constituting the euthyroid sick syndrome (ESS), we aimed in this research to elucidate the possible relation between IL-6 & IL-10 and any documented ESS in a cohort of patients with NTI.</p> <p>Methods</p> <p>Sixty patients and twenty healthy volunteers were recruited. The patients were subdivided into three subgroups depending on their underlying NTI and included 20 patients with chronic renal insufficiency (CRI), congestive heart failure (CHF), and ICU patients with myocardial infarction (MI). Determination of the circulating serum levels of IL-6 and IL-10, thyroid stimulating hormone (TSH), as well as total T4 and T3 was carried out.</p> <p>Results</p> <p>In the whole group of patients, we detected a significantly lower T3 and T4 levels compared to control subjects (0.938 ± 0.477 vs 1.345 ± 0.44 nmol/L, p = 0.001 and 47.9 ± 28.41 vs 108 ± 19.49 nmol/L, p < 0.0001 respectively) while the TSH level was normal (1.08+0.518 μIU/L). Further, IL-6 was substantially higher above controls' levels (105.18 ± 72.01 vs 3.35 ± 1.18 ng/L, p < 0.00001) and correlated negatively with both T3 and T4 (r = -0.620, p < 0.0001 & -0.267, p < 0.001, respectively). Similarly was IL-10 level (74.13 ± 52.99 vs 2.64 ± 0.92 ng/ml, p < 0.00001) that correlated negatively with T3 (r = -0.512, p < 0.0001) but not T4. Interestingly, both interleukins correlated positively (r = 0.770, p = <0.001). Moreover, IL-6 (R<sup>2 </sup>= 0.338, p = 0.001) and not IL-10 was a predictor of low T3 levels with only a borderline significance for T4 (R<sup>2 </sup>= 0.082, p = 0.071).</p> <p>By subgroup analysis, the proportion of patients with subnormal T3, T4, and TSH levels was highest in the MI patients (70%, 70%, and 72%, respectively) who displayed the greatest IL-6 and IL-10 concentrations (192.5 ± 45.1 ng/L & 122.95 ± 46.1 ng/L, respectively) compared with CHF (82.95 ± 28.9 ng/L & 69.05 ± 44.0 ng/L, respectively) and CRI patients (40.05 ± 28.9 ng/L & 30.4 ± 10.6 ng/L, respectively). Surprisingly, CRI patients showed the least disturbance in IL-6 and IL-10 despite the lower levels of T3, T4, and TSH in a higher proportion of them compared to CHF patients (40%, 45%, & 26% vs 35%, 25%, & 18%, respectively).</p> <p>Conclusion</p> <p>the high prevalence of ESS we detected in NTI including CRI may be linked to IL-6 and IL-10 alterations. Further, perturbation of IL-6 and not IL-10 might be involved in ESS pathogenesis although it is not the only key player as suggested by our findings in CRI.</p

    SNARE Protein Mimicry by an Intracellular Bacterium

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    Many intracellular pathogens rely on host cell membrane compartments for their survival. The strategies they have developed to subvert intracellular trafficking are often unknown, and SNARE proteins, which are essential for membrane fusion, are possible targets. The obligate intracellular bacteria Chlamydia replicate within an intracellular vacuole, termed an inclusion. A large family of bacterial proteins is inserted in the inclusion membrane, and the role of these inclusion proteins is mostly unknown. Here we identify SNARE-like motifs in the inclusion protein IncA, which are conserved among most Chlamydia species. We show that IncA can bind directly to several host SNARE proteins. A subset of SNAREs is specifically recruited to the immediate vicinity of the inclusion membrane, and their accumulation is reduced around inclusions that lack IncA, demonstrating that IncA plays a predominant role in SNARE recruitment. However, interaction with the SNARE machinery is probably not restricted to IncA as at least another inclusion protein shows similarities with SNARE motifs and can interact with SNAREs. We modelled IncA's association with host SNAREs. The analysis of intermolecular contacts showed that the IncA SNARE-like motif can make specific interactions with host SNARE motifs similar to those found in a bona fide SNARE complex. Moreover, point mutations in the central layer of IncA SNARE-like motifs resulted in the loss of binding to host SNAREs. Altogether, our data demonstrate for the first time mimicry of the SNARE motif by a bacterium
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