Host immune response in sepsis due to ventilator-associated pneumonia: how is it different?

Current evidence regarding potentially different host response mechanisms in sepsis according to the type of initiating infection is sporadic. It is possible that alterations in cell populations, variations in effector molecules, and the degree of apoptosis differ between sepsis caused by ventilator-associated pneumonia (VAP) and non-VAP sepsis. VAP is one of the most common infections and leading causes of sepsis in the intensive care unit, and mortality remains high. A better understanding of the unique pathophysiologic features of VAP is needed in order to develop interventions that target those specific pathways

Abstract Data Visualisation in Mobile VR Platforms

Data visualisation, as a key tool in data understanding, is widely used in science and everyday life. In order data visualisation to be effective, perceptual factors and the characteristics of the display interface play a crucial role. Virtual Reality is nowadays accepted as a valid medium for scientific visualisation, because of its inherent characteristics of real-world emulation and intuitive interaction. However, the use of VR in abstract data visualisation is still limited. In this research, I investigate the use and suitability of mobile phone-based Virtual Reality as a medium for abstract data visualisation. I develop a prototype VR Android application and visualise data using the Scatterplot and Parallel Coordinates methods. After that, I conduct a user study to compare the effectiveness of the mobile VR application compared to a similar screen-based one by implementing some data exploration scenarios. The study results, while not being statistically significant, show improved accuracy and speed in the mobile VR visualisation application. The main conclusions are two-fold: Virtual Reality is beneficial for abstract data visualisation, even in the case of limited processing power and display resolution. Mobile VR, an affordable alternative to expensive desktop VR set-ups can be utilized as a data visualisation platform

The kinetics of T regulatory cells in shock: beyond sepsis

During the past decade, there have been an increasing number of studies investigating the precise role of T regulatory cells in human disease. First recognized for their ability to prevent autoimmunity, T regulatory cells control effector CD4+ and CD8+ T lymphocytes and innate immune cells by several different suppressive mechanisms, like cell to cell contact, secretion of inhibitory cytokines and cytolysis. This suppressive function of T regulatory cells could contribute in a similar way to the profound immune dysfunction seen in critical illness whether the latter is due to sepsis or severe injury

Molecular basis of atheromatosis in children

Atheromatosis is a lifelong process that begins and develops silently even during fetal development and gen­erally shows clinical manifestations in adult life. The initiation and progressive formation of atheromatic lesions represents a complex interplay of both genetic and environmental factors. Over the last decades there have been numerous studies detecting atherosclerotic lesions in the coronary arteries of children and adolescents and demonstrating the early onset of this disease. Although more research is required in order to unravel the full genetic repertoire of atherogenesis, scientists have already made real progress towards understanding the molecular basis of early atheromatosis and the aetiopathogenesis of this complex disease involves genes related to inflammation, lipid metabolism, MMPs, epigenetic alterations of DNA and gene-environment interactions. Atheromatosis in children and adolescents is really a reversible process and anatomic changes observed in early atheromatosis are modifiable. Thus, primary prevention strategies beginning in childhood have great potential and might result in prevention of adult cardiovascular diseas

Heterotrophic bacterial growth and substrate utilization in the oligotrophic Eastern Mediterranean (Aegean Sea)

Heterotrophic bacterial growth and substrate utilization were studied in March and September of 1997 in the oligotrophic Aegean Sea. Maximum velocities of ectoproteolytic activity (ectoaminopeptidase ctivity, EAP), as well as amino acid assimilation and respiration rates (AA-A, AA-R) were measured along with bacterial production (protein synthesis). At the northern stations which are influenced by the input of the Black Sea waters, rates at 5 m depth of EAP, AA-A and bacterial production were 2 to 3 times higher than at southern stations. Influenced by the Black Sea water, mean bacterial numbers in the 0-100 m layer showed typical oceanic concentrations averaging 0.7 x 10 6 cells ml -1 . These values, along with low bacterial production rates (30 ng C l -1 h -1 ) implied slow growth for bacteria and/or that a large number among them were inactive. Neither bacterial abundance nor production were correlated with primary production. The percentage of amino acids respired was higher in September compared to March, particularly in the northern Aegean (mean 69 %). The enzyme kinetic analysis showed a biphasic model, the transition between the high and low affinity enzymes being obtained at 50 ΜM. Ectoaminopeptidase activity was weakly correlated with bacterial production (p < 0.05), but strongly correlated with respiration rates of amino acids (p < 0.001), suggesting that the substrate used was devoted to maintain energy requirements

Fetal RHD genotyping by maternal plasma analysis

Determination of the fetal RhD typing using free fetal DNA in maternal plasma, is beginning to gain widespread acceptance in Europe and may allow genetic analysis without the use of invasive techniques. The purpose of this study was to extract DNA from maternal plasma and determine the accuracy of the non-invasive prenatal determination of fetal RhD genotyping with the use of real-time PCR. We analyzed 48 RhD-negative pregnant women in the 16th to 40th weeks of pregnancy using real-time PCR, primers and probes targeting the RHD gene. Results were compared with serologic RhD typing of the newborns. Among the 48 pregnant women who participated in the study, 9 were in the second trimester of pregnancy and 39 in the third trimester. Twenty nine fetuses genotyped as RhD positive and 19 as RhD negative. Neither false-negative nor false-positive results were observed. The present report demonstrates that a reliable fetal RHD genotype determination can be achieved with 100% accuracy. It is therefore possible to considerthat such an assay could be systematically proposed to all RhD-negative pregnant women in order to use RhD prophylaxis more effectively

The fate of biogenic iron during a phytoplankton bloom induced by natural fertilisation: Impact of copepod grazing

International audienceThe impact of copepod grazing on Fe regeneration was investigated in a naturally iron fertilised area during KEOPS (Kerguelen Ocean and Plateau compared Study, Jan.-Feb. 2005). 55Fe labelled natural plankton assemblages (< 200 μm) were offered as food to copepod predators sampled in the field (Calanus propinquus, Rhincalanus gigas, Metridia lucens and Oithona frigida). Diatoms (Eucampia antarctica, Corethron inerme and Navicula spp.) constituted the bulk of the protists whereas microzooplankton (i.e. ciliates and dinoflagellates) were in very low abundance. Copepod grazing on phytoplankton ranged from 0.3 to 2.6 µgC ind-1 d-1 and reflected low utilisation of the food stocks (1-10% of total Chlorophyll a d-1) and low daily rations (0.2-3.3 % body C d-1). Copepod grazing resulted in a 1.7-2.3-fold increase in Fe regeneration. Fe speciation determined by extraction onto C18 columns showed that less than 1% of the regenerated Fe was complexed with hydrophobic organic ligands. This suggests that Fe was regenerated as inorganic species and/or bound to freely soluble organic ligands. The biogenic Fe budget established from our study and literature based data indicates that most of the primary production is recycled through the detrital pool, which represents the largest Fe pool (49% of total Fe). Our iron budget further indicates that mesozooplankton and diatoms represent the dominant Fe biomasses above the Kerguelen plateau. The rate of Fe regeneration accounts for half of the Fe demand, strengthening the need for new Fe sources to sustain the massive phytoplankton bloom above the Kerguelen plateau

Εφαρμογή πρωτοκόλλου τροποποίησης του τρόπου ζωής σε παιδιά με αυξημένο σωματικό βάρος: συσχετίσεις με βιοδείκτες και παραμέτρους σχετιζόμενες με το στρες και εκτίμηση της κατάστασης υγείας μέσω του ευστασιομέτρου

Διερευνήσαμε τις σχέσεις μεταξύ πολλαπλών δεικτών στρες, φλεγμονής και μεταβολισμού και παραμέτρων σύστασης σώματος σε 121 (43 αγόρια, 78 κορίτσια) παιδιά και εφήβους , ηλικίας 5 έως 15 ετών. Οι συμμετέχοντες χωρίστηκαν σε 2 ομάδες: συμμετέχοντες με φυσιολογικό σωματικό βάρος (N=40, BMI z-score = -0.1923 ± 0.6), και συμμετέχοντες με υπερβάλλον βάρος και παχυσαρκία (N=81, BMI z-score= 2.1947 ± 1.4). Όλοι οι συμμετέχοντες συμπλήρωσαν το ερωτηματολόγιο εκτίμησης άγχους για παιδιά STAIC και το ερωτηματολόγιο CDI που εκτιμά τα συμπτώματα κατάθλιψης. Παράλληλα, σε όλα τα παιδιά έγινε εκτίμηση του κιρκάδιου ρυθμού έκκρισης κορτιζόλης σιέλου, μέτρηση της κορτιζόλης τρίχας, της κορτιζόλης ορού, της C-αντιδρώσας πρωτεΐνης υψηλής ευαισθησίας (HsCRP), της φερριτίνης, αλλά και δείκτες μεταβολισμού , όπως είναι τα λιπίδια και η ινσουλίνη. Η σύσταση σώματος εκτιμήθηκε με την μέθοδο της εξελιγμένης βιοηλεκτρικής εμπέδησης, ενώ η εκτίμηση της διακύμανσης καρδιακής συχνότητας έγινε με χρήση φωτοπληθυσμογράφου του ευστασιομέτρου. Οι συμμετέχοντες με υπερβάλλον σωματικό βάρος ή παχυσαρκία εμφάνισαν υψηλότερο σκορ στο ερωτηματολόγιο STAIC, υψηλότερο BMI z-score και υψηλότερο ποσοστό σωματικού λίπους συνολικά και ενδοσπλαχνικά. Η διακύμανση καρδιακής συχνότητας δεν διέφερε μεταξύ των ομάδων. Στο σύνολο του δείγματος παρατηρήθηκε σημαντική συσχέτιση των επιπέδων HsCRP, φερριτίνης, δεικτών φλεγμονής και δεικτών ινσουλινοαντίστασης. Παρατηρήθηκε επίσης μια ισχυρή συσχέτιση κορτιζόλης τρίχας και HsCRP, υποδεικνύοντας την σχέση χρόνιου στρες και φλεγμονής, ενώ η συσσώρευση σωματικού λίπους στα παιδιά και τους εφήβους φάνηκε να συσχετίζεται με κλινικούς και εργαστηριακούς δείκτες στρες, φλεγμονής και ινσουλινοαντίστασης. Επιπρόσθετα, μελετήθηκαν ξεχωριστά οι παραπάνω δείκτες σε 50 προεφηβικά κορίτσια, εκ των οποίων τα 24 είχαν φυσιολογικό σωματικό βάρος και τα 26 είχαν διάγνωση παχυσαρκίας. Σε αυτό το μικρότερο δείγμα της μελέτης παρατηρήθηκε ότι τα κορίτσια με παχυσαρκία είχαν υψηλότερα επίπεδα κορτιζόλης τρίχας και κορτιζόλης σιέλου όπως αυτή εκτιμάται με το εμβαδό κάτω από την καμπύλη (Area under the curve with respect to the ground- AUCg) (p &lt; 0.001 and p &lt; 0.002, αντίστοιχα) σε σχέση με τα κορίτσια με φυσιολογικό σωματικό βάρος. Παρατηρήθηκε επίσης θετική συσχέτιση μεταξύ κορτιζόλης τρίχας και BMI Z-score (rho = 0.327, p&lt; 0.025), ενώ αναδείχθηκε μια θετική συσχέτιση κορτιζόλης τρίχας και κορτιζόλης σιέλου (rho=0.3, p&lt;0.048). Συμπερασματικά η κορτιζόλη τρίχας είναι ένας ευαίσθητος δείκτης για την ανίχνευση του χρόνιου στρες, ενώ η παχυσαρκία στα παιδιά φαίνεται να σχετίζεται με την απορρύθμιση της έκκρισης κορτιζόλης. Τέλος, προχωρήσαμε στην ανάλυση του FGF21 σε ένα δείγμα 78 κοριτσιών από το αρχικό δείγμα σε όλα τα στάδια εφηβείας (50 κορίτσια με υπερβάλλον σωματικό βάρος ή παχυσαρκία και 28 κορίτσια με φυσιολογικό σωματικό βάρος). Στα κορίτσια με φυσιολογικό σωματικό βάρος παρατηρήθηκε μια σημαντική συσχέτιση των επιπέδων FGF21 και της κορτιζόλης τρίχας (r=0.54, p&lt;0.006) αλλά και της κορτιζόλης σιέλου (r= 0.463, p&lt; 0.020). Ο FGF21 φαίνεται να επιδρά στον άξονα του στρες και να διαμεσολαβεί την σχέση παχυσαρκίας και στρες.We examined the associations between multiple indices of stress, inflammation and metabolism vs. body composition parameters in 121 (43 boys, 78 girls) children and adolescents, aged 5-15 y. Participants were divided into 2 groups: normal weight (N=40, BMI z-score = -0.1923 ± 0.6), and overweight/obese (N=81, BMI z-score= 2.1947 ± 1.4). All subjects completed the State-Trait Anxiety Inventory for Children (STAIC) and Children’s Depression Inventory (CDI), and had cortisol measured in hair, diurnal series of saliva, and morning serum. Circulating concentrations of high sensitivity C-reactive protein (hsCRP) and other inflammation biomarkers, such as ferritin, and metabolic indices, such as lipids and insulin, were also obtained. Body composition analysis was performed with a clinically validated, advanced bioimpedance apparatus (BIA), while heart rate variability (HRV) was measured as an additional stress biomarker by photoplethysmography (PPG) (eustasiometer). The overweight/obese group had a higher STAIC-state score, BMI-z score, waist-to-hip ratio, skeletal muscle mass, and total and abdominal fat mass, and a lower percent fat-free mass and bone density than the normal weight subjects. HRV did not differ between the two groups. In the entire population, percent fat mass correlated strongly with circulating hsCRP (r=0.397, p=0.001), ferritin, and other inflammatory biomarkers, as well as with indices of insulin resistance. A strong correlation between hair cortisol and serum hsCRP was also observed (r=0.777, p&lt;0.001), suggesting presence of interrelated chronic stress and inflammation. Thus, body fat accumulation in children and adolescents was associated with an elevation in clinical and laboratory biomarkers of stress, inflammation, and insulin resistance. However, unlike adults, neither HRV, nor skeletal muscle mass were influenced negatively by adiposity. -BIA-ACC and PPG can be used as a direct screening and monitoring tool for assessing overweight- and obesity -related health risks in children and adolescents. Moreover, we examined these associations in a smaller group including only 50 girls (tanner stage 1): 25 obese girls and 25 normalweighted, age-matched girls were enrolled. In this smaller part of the study both hair cortisol concentrations and salivary cortisol AUCs were higher in the obese than the normal-weight girls (p &lt; 0.001 and p &lt; 0.002, respectively). A positive correlation between hair cortisol and BMI Z-score was found (rho = 0.327, p&lt; 0.025), while hair cortisol correlated positively with salivary cortisol AUCg (rho = 0.3, p &lt; 0.048). We conclude that obese prepubertal girls have higher hair and salivary cortisol concentrations than their age-matched lean counterparts. Hair cortisol assessment seems to be a sensitive method of evaluating systemic cortisol exposure, which is supported by our finding that hair cortisol is associated with salivary concentrations of the hormone. Cortisol is the key hormone of the stress response. Childhood obesity has been associated with cortisol production dysregulation. Our findings suggest a positive association between obesity in prepubertal girls and elevated cortisol concentrations, measured in saliva and hair. Finally, in a group of 78 girls (50 girls with obesity or overweight and 28 normal-weight girls) from our sample we examined the associations between fibroblast growth factor 21 (FGF21) and the above mentioned stress, inflammation and body composition indices. In normal-weight girls we observed a correlation between hair cortisol concentration and FGF21 levels (r=0.54, p=0.006), as well as a correlation between salivary cortisol concentration and FGF21 levels (r=0.463, p=0.020). FGF 21 possibly plays an important role in the HPA axis activation