Investigating the functionalization of liposomes with NFL-TBS. 40-63 peptide as a promising drug delivery system

The NFL-peptide was discovered almost 20 years ago, and its targeting properties were assessed alone or in combination with lipid nanocapsules (LNC), magnetic porous silicon nanorods, or gold nanoparticles. Results highlighted a better targeting of cancer cells, in particular glioblastoma and pancreas cancer. Considering the large use of liposomes (LPs) as an hydrophilic drug delivery system, this study explored the possibility to functionalize liposomes with three different sequences of NFL-peptides: native (NFL-peptide), biotinylated (BIOT-NFL) and coupled to fluorescein (FAM-NFL). Dynamic Light Scattering (DLS) complemented by cryo-electron microscopy (CEM) showed a peculiar ultrastructural arrangement between NFL-peptides and liposomes. Based on this architectural interaction, we investigated the biological contribution of these peptides in LPs-DiD glioblastoma cellular uptake. Flow cytometry complemented by confocal microscopy experiments demonstrated a consequent and systematic increased uptake of LPs-DiD into F98 cells when their surface was decorated with NFL-peptides. The intra-cellular distribution of these liposomes via an organelle tracker indicated the presence of LPs-DiD in lysosomes after 4 h. Based on the properties of this NFL-peptide, we showed in this work the crucial role of NFL peptide as an effective and promising actor to potentiate nanoparticles entry in glioblastoma cell lines.

Cardiac features of MIS-C: MRI and Speckle-tracking data

Introduction

In November 2019, the first case of SARS-CoV-2 infection was reported in China, the first European case was declared 2 months later in January 2020. While the pediatric population seemed to be less affected by SARS-CoV-2, an alert was launched in April 2020 following multiple cases of multisystem inflammatory syndrome in children (MIS-C), secondary to SARS-CoV-2 infection. The presentation shares clinical features with Kawasaki disease but involves almost systematically cardiac dysfunction. Cardiac involvement is central in MIS-C and represents the main cause of morbidity.

Objective

In this study, we therefore aimed to assess the myocardial damage in patients with MIS-C using MRI during the acute phase as well as left ventricular and atrial longitudinal strain during the acute phase and after recovery.

Method

We performed a single-center prospective cohort and case-control study. Between September 2020 and January 2022, we included 39 patients hospitalized for MIS-C in our center. We performed left ventricular and atrial longitudinal 2D strain analysis on admission and during follow-up; the analysis was compared to a matched control population. Patients above 4 years old with increased troponin underwent cardiac MRI.

Results

Of 22 patients who underwent cardiac MRI, 14 (64%) presented myocardial edema and 6 (27%) late gadolinium enhancement, the latter being associated with myopericarditis and impaired LVEF (P < 0.001), older patients (P = 0.027) and elevated ferritin (P = 0.03). We found a decrease in left ventricular and atrial longitudinal strain on admission as compared to controls with a significant improvement at 1 month post-discharge (P < 0.0001). The alteration in LV strain persisted beyond one month according the comparison with the control population (P = 0.01).

Conclusion

Only little is known about the long-term follow-up and prognosis in MIS-C patients. Our study demonstrated the myocardial inflammation during the acute phase of MIS-C as well as the impaired LA and LV myocardial deformation that persists for at least several weeks after the acute phase. Thus, we believe MRI and LV/LA strain could help us individualize our MIS-C patients follow-up.

Patients asthmatiques hospitalisés pour infection à SARS-CoV-2 ou pour grippe : facteurs de risques de mauvais pronostic

Introduction

Lors de l’émergence du coronavirus SARS-CoV-2, les patients asthmatiques ont été initialement considérés comme des patients à risque, comme pour les virus respiratoires et notamment celui de la grippe. Par la suite, ce surisque n'a pas été retrouvé, avec des prévalences d'asthmatiques parmi les patients hospitalisés pour Covid-19 inférieures à la prévalence de l'asthme en population générale. L'objectif de ce travail a été de comparer la prévalence de l'asthme et les facteurs de risque associés à un mauvais pronostic chez des patients asthmatiques hospitalisés pour Covid-19 ou grippe.

Methodes

Cette étude rétrospective a été conduite à partir des données de l'Entrepôt de Données de Santé (EDS) de l'AP-HP, regroupant les données médico-administratives des séjours hospitaliers. Les patients adultes hospitalisés entre le 01/01/2020 et le 30/06/2020 avec une PCR SARS-CoV2 positive dans les 15 jours précédents le séjour ou au cours de leur séjour ont constitué la cohorte patients Covid-19. A partir des séjours hospitaliers ayant un code CIM-10 J09, J10 ou J11, deux cohortes de patients grippe ont été construites : cohorte grippe saison 2018-2019 (séjours ente le 01/11/2018 et le 31/03/2019) et cohorte grippe saison 2017-2018 (séjours ente le 1/11/2017 et le 31/03/2018). Les antécédents d'asthme et les autres comorbidités ont été recherchés dans les codages des séjours hospitaliers grippe ou Covid-19 et antérieurs. L'obésité et tabagisme ont été également recherchés spécifiquement par REGEX dans les compte-rendu. Les facteurs associés à un passage en réanimation ou à un décès hospitalier ont été recherchés par des régression logistiques multivariées, avec une sélection pas à pas descendante sur le critère AIC.

Resultats

9009 patients ont été hospitalisés à l'AP-HP pour Covid-19 entre 01/2020 et 06/2020, 3119 pour grippe pendant la saison 2017-2018, 3266 pendant le saison 2018-2019. La prévalence de l'asthme était significativement plus élevée parmi les patients hospitalisés pour grippe (n=283, 9.1%, IC95% [8.1 -10.1] en 2017-2018 et n=309, 9.5%, IC95% [8.5 - 10.5] en 2018-2019) contre 4.5% pour les patients Covid-19 (n=402, IC95% [4-4.9], p<0.001 pour les deux comparaisons). L'obésité a été retrouvée comme facteur de risque de mauvais pronostic chez les patients asthmatiques lors de la saison 2017-2018 de grippe (ORa=2.22, IC95%[1.25-3.96]), le tabagisme (ORa=2.95, IC95% [1.67- 5.39]) et l'insuffisance cardiaque pour la saison 2018-2019 (ORa= 2.05, IC95%[1.03-4.15]). Chez les asthmatiques Covid-19, le tabac et l'obésité étaient des facteurs de risque de forme grave (ORa=1.57, IC95% [1.03-2.40]) et ORa=1.55, IC95%[1.00-2.41] respectivement). Avoir plus de 70 ans (ORa=0.64 IC95%[0.42-0.97]) et le sexe féminin (ORa=0.38, IC95%[0.25-0.58]) étaient associés à un moindre risque de forme grave.

Conclusion

Nos résultats montrent une prévalence plus faible de l'asthme parmi les patients hospitalisés pour Covid-19 que parmi ceux hospitalisés pour grippe. Les facteurs de risque de forme grave, sauf l'obésité, diffèrent pour les 2 virus, et selon la saison grippale.Ceci pourrait être lié entre autres à une forte adhérence des patients asthmatiques aux mesures de confinement et des gestes barrières, mais également à une différence de susceptibilité aux virus respiratoires.

Mots clés Covid 19 ; Asthme ; Grippe ; Mortalité ; Réanimation

Déclaration de liens d'intérêts Camille Taillé déclare des rémunérations de la part de Novartis, GSK, sanofi, Astrazeneca, Chiesi, sans lien avec le travail présenté

Development and validation of a Patient-Reported Outcome in systemic sclerosis: the Hand scleroDerma lived Experience Scale (HAnDE Scale)

OBJECTIVES

to develop and validate a Patient Reported Outcome (PRO) scale-the HAnDE (Hand-ScleroDerma Disease lived Experience) scale-assessing the lived experience of hand involvement in patients with systemic sclerosis (SSc).

METHODS

explanatory sequential mixed-method study with two phases: 1) PRO development through an Inductive Process to analyze the Structure of lived Experience approach, involving 21 SSc patients, 2) PRO validation by assessing the psychometric properties of the scale among 105 SSc patients.

RESULTS

1) Phase-1 enabled to generate the 18-item provisional scale. 2) The mean total score of the scale was 29,16 (SD 16,15). The item reduction process retained 16 items with 5 levels of answers (range 0-64). Internal consistency of the 16-item version was excellent (Cronbach-alpha coefficient=0,946). Construct validity was very good, the Principal Component Analysis being in favour of a unidimensional instrument, with one factor explaining 56% of the variance, and concurrent validity being confirmed: Cochin Hand Function Scale r=0,66; Health Assessment Questionnaire-Disability index r=0.58; Hospital Anxiety Depression, anxiety r=0,51, depression r=0,4; Mouth Handicap in Systemic Sclerosis r=0,61; SF-36, physical component r=-0,48, mental component r=-0,46; and Kapandji score r=-0,46. The correlations were statistically significant (p<0,05).

CONCLUSION

We propose, for future trials and clinical practice in SSc, a new PRO the HAnDE scale, that assesses all the dimensions -functional, aesthetic, relational, existential, and emotional- of the lived experience of hand involvement.

AB0401 CAN DUAL-ENERGY CT LUNG PERFUSION DETECT ABNORMALITIES AT THE LEVEL OF LUNG CIRCULATION IN SYSTEMIC SCLEROSIS (SSC)? PRELIMINARY EXPERIENCE IN 101 PATIENTS

Background:

Systemic sclerosis (SSc) is an autoimmune disorder that is characterized by a interplay of vascular abnormalities, immune system activation and an uncontrolled fibrotic response associated with interstitial lung disease affecting about 40% of patients. Identification of ILD relies on high-resolution CT that identify features suggestive of the histologic patterns of SSc(1). CT is used to determine pattern and extent of ILD and participates in the prediction of ILD progression(2).

All group of pulmonary hypertension (PH) may occur with an overall prevalence reported in up to one fifth of patient. Whereas extensive SSc-ILD can be responsible for PH, PH can also be seen as a consequence of myocardial abnormalities or as primarily affecting small pulmonary arteries and classified as pulmonary arterial hypertension.

Dual-energy CT introduction offers perspectives in the evaluation of SSc-related pulmonary manifestations. While these are not strictly perfusion images, they have been reported as adequate surrogate markers of lung perfusion (3). In the field of PH, detection of perfusion defects highly concordant with V/Q scintigraphic findings has been reported in the diagnostic approach of CTEPH but also in the differential diagnosis between PAH and peripheral forms of CTEPH (4).

Objectives:

To investigate lung perfusion abnormalities in patients with SSc.

Methods:

The study population included 101 patients who underwent dual-energy CT (DECT) angiography in the follow-up of SSc. CT examinations were obtained on a 3rd-generation dual-source CT system with reconstruction of morphologic and perfusion images. All patients underwent pulmonary function tests within two months of the follow-up CT scan. Fifteen patients had right heart catheterization-proven PH.

Results:

Our population included patients without SSc lung involvement (Group 1; n=37), patients with SSc-related ILD (Group 2; n=56) of variable extent (Group 2a: ≤10%: n=17; Group 2b: between 11-50%: n=31; Group 2c: >50%: n=8) and patients with PVOD/PCH (Group 3; n=8). Lung perfusion was abnormal in 8 patients in G 1 (21.6%), 14 patients in G 2 (25%) and 7 patients in G 3 (87.5%). Perfusion changes were mainly composed of bilateral perfusion defects, including patchy, PE-type perfusion defects and areas of hypoperfusion of variable size. In G 1 and G 2a (n=54): (a) patients with abnormal lung perfusion (n=14) had a significantly higher proportion of NYHA III/IV scores of dyspnea (p=0.031), a shorter mean walking distance at the 6MWT (p=0.042) and a trend towards lower mean DLCO% (p=0.055) when compared to patients with normal lung perfusion (n=40); (b) a negative albeit weak correlation was found between the iodine concentration in both lungs and the DLCO% (r=-0.27; p=0.059) whereas no correlation was found with PAPs (r=0.16; p=0.29) and walking distance during the 6MWT (r=-0.029; p=0.84).

Conclusion:

DECT lung perfusion provides complementary information to HRCT scans, depicting perfusion changes in SSc patients with normal or minimally infiltrated lung parenchyma.

References:

[1]Kim EA, Lee KS, Johkoh T, Kim TS, Suh GY, Kwon OJ, et al. Interstitial lung diseases associated with collagen vascular diseases: radiologic and histopathologic findings. Radiogr Rev Publ Radiol Soc N Am Inc. 2002 Oct;22 Spec No:S151-165.

[2]Goh NSL, Desai SR, Veeraraghavan S, Hansell DM, Copley SJ, Maher TM, et al. Interstitial lung disease in systemic sclerosis: a simple staging system. Am J Respir Crit Care Med. 2008 Jun 1;177(11):1248–54.

[3]Fuld MK, Halaweish AF, Haynes SE, Divekar AA, Guo J, Hoffman EA. Pulmonary perfused blood volume with dual-energy CT as surrogate for pulmonary perfusion assessed with dynamic multidetector CT. Radiology. 2013 Jun;267(3):747–56.

[4]Giordano J, Khung S, Duhamel A, Hossein-Foucher C, Bellèvre D, Lamblin N, et al. Lung perfusion characteristics in pulmonary arterial hypertension and peripheral forms of chronic thromboembolic pulmonary hypertension: Dual-energy CT experience in 31 patients. Eur Radiol. 2017 Apr;27(4):1631–9.

Disclosure of Interests:

None declared

Faire face au COVID-19, mise en place de novo d’une unité mutualisée « COVID-19 non réanimatoire » : organisation et résultats

Introduction

La pandémie à COVID-19 a touché presque tous les pays du monde, dont la France. Tous les départements français ont ouvert des unités dédiées pour la gestion de la phase aiguë de l’épidémie. Au sein de notre site, notre structure a été la seule à accueillir une unité pour gérer des patients confirmés COVID-19 positifs. En l’absence de soins intensifs sur place, ces patients étaient triés au SAU et ne venaient que les patients sans indication de soins intensifs en raison du bénéfice/risque attendu (âge, comorbidités). Pour activer cette unité, une équipe mutualisée a été mise en place que ce soit au niveau du personnel médical PM (seniors, internes, externes) que personnel non médical (PNM) détachés des services de médecine interne, pédiatrie, médecine du sport, consultation, endocrinologie, hépatologie de notre CHU. Un support psychologique a été proposé aux soignants et aux familles par une équipe mobile de psychiatrie. L’activité quotidienne a été réorganisée après la création de plusieurs binômes junior-senior, en service de 8 h à 19 h, 7 j/7. La continuité des soins a été assurée chaque jour par 3 staffs pour permettre respectivement les transmissions de la nuit entre PM et PNM ; l’état des lieux après la visite du matin ; les projets pour le lendemain. Tous les patients ont été réévalués chaque jour et réorientés selon une échelle de gravité structurée par 5 codes-couleurs. Les externes ont eu pour mission de contacter les familles du fait de la limitation des visites, ainsi que les médecins traitants afin d’améliorer la gestion après le RAD. Les patients ont été traités par oxygénothérapie et protocoles d’antibiothérapie et morphine.

Matériels et méthodes

Analyse descriptive des données personnelles, de la mortalité brute et des issues de l’hospitalisation.

Résultats

Entre le 13 mars et le 19 mai, 147 patients, 56 % d’eux de sexe féminin, ont été hospitalisés dans cette unité d’une capacité maximale de 25 lits. L’âge moyen était de 69 ans [18 ; 97]. La durée moyenne du séjour a été de 5 jours [0 : 29]. La mortalité totale était du 20,4 %, dont 51 % des patients sont rentrés vers leur domicile ou vers des EHPAD. Ensuite, 14,3 % des patients ont été transférés vers un autre service de médecine aiguë, et 12,2 % des patients a poursuit les soins dans un SSR.

Conclusion

L’organisation de ce service montre comme une équipe de PM et PNM avec fonds de travail différentes peut être rapidement mise en place pendant une période de crise. La présence d’un service dédié à la gestion des cas de COVID-19 sans indication à soins intensifs peut soulager des autres services au sein d‘un groupe hospitalier qui travaille en coordination. La mortalité des patients hospitalisés dans ce service reste baisse considérant les comorbidités et l’âge des patients. La durée courte du séjour a permis d’accueillir un grand nombre de patients et de garantir de places en médecine aiguë standard au sein du GH.

SAT0244 PROGNOSIS OF LARGE VESSEL INVOLVEMENT IN LARGE VESSEL VASCULITIS

Background:

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are the two main forms of large vessels vasculitis (LVV). Vessel inflammation leads to aneurysms, wall thickening, stenosis, and, in some cases, complete occlusion of the artery. Due to the wide variation in the course of LVV, predicting outcome is challenging. To our knowledge, data regarding prognosis factors of LVI in LVV patients and comparison of outcome of LVI in GCA and TAK are lacking. An early identification of patients with higher mortality could help to prevent deaths and vascular complications.

Objectives:

To assess prognosis factors and outcome of large vessel involvement (LVI) in large vessels vasculitis (LVV) patients.

Methods:

Retrospective multicenter study of characteristics and outcomes of 417 patients with LVI including 299 Takayasu arteritis (TAK) and 118 Giant cell arteritis (GCA-LVI) were analyzed. Logistic regression analysis assessed prognosis factors in LVV patients. Outcome of LVI among TAK and GCA-LVI patients (ischemic complications, aneurysms complications, relapses and revascularization) were assessed.

Results:

In multivariable analysis, stroke/transient ischemic attack [HR: 3.63 (1.46 - 9.04), p=0.006] was independently associated with vascular complications in LVV. The 10-years aneurysm free survival was significantly lower [67% (48 – 93) vs 89% (84 – 95), p=0.02] in GCA-LVI compare to TAK patients. The 5-years relapse free survival was significantly lower [47% (37 – 60) vs 69% (63 – 75), p<0.001,] in GCA-LVI compare to TAK patients. The 10-years revascularization free survival was significantly lower [55% (48 – 64) vs 76% (59 – 99), p<0.001] in TAK compare to GCA-LVI patients. After a median follow-up of 5 years, 16 (5.4%) TAK and 7 (5.9%) GCA-LVI patients died, mainly of aneurysm (26%) and ischemic complications (26%).

Conclusion:

This large nationwide cohort of LVI provided prognosis factors of vascular complications in LVV patients. TAK and GCA-LVI have different long-term outcome in term of aneurysm development, relapse and revascularization.

Disclosure of Interests:

None declared

[Tick-borne relapsing fever : An unrecognized cause of fever in travellers]

INTRODUCTION

Tick-borne relapsing fever is a usual cause of fever in West Africa. Except relapsing febrile episodes, there are no pathognomonic signs and diagnosis is difficult because Borrelia density in patient's blood is low.

CASE REPORTS

Tick-borne relapsing fever was revealed by the presence of spirochetes in a blood sample to search malaria in two men, 24 and 31 year-old, returned from Mali.

CONCLUSION

This diagnosis should be evocated in patients having fever after a trip in infested area, as malaria, both infections can be associated.

Stage IV cutaneous squamous cell carcinoma: treatment outcomes in a series of 42 patients

BACKGROUND

The prevalence and incidence of cutaneous squamous cell carcinoma (cSCC) are increasing due to the ageing of the population and sun exposure. Advanced cSCC forms (locally advanced and/or locoregional metastatic and/or distant metastatic) account for approximately 3% of cSCC and can result in death.

OBJECTIVE

Analysis of the clinical characteristics and treatment outcomes in stage IV cSCC with unresectable locoregional extension and/or the presence of metastases.

METHODS

A retrospective study was conducted at a single-centre university hospital for stage IV cSCC patients followed between 1 January 2008 and 31 December 2015. Descriptive analyses (demographic, anatomo-clinical characteristics, treatment sequences, response to treatment and survival analysis) were performed.

RESULTS

The study included 42 patients (median age = 75.5 years) with a diagnosis of stage IV cSCC who were treated with at least one line of chemotherapy and/or cetuximab. At the time of diagnosis, 85.7% of the patients had locoregional extension (19% of locally advanced and 67% of locoregional metastatic) and 14.3% had distant metastatic disease. Regarding treatment, 40% and 36% of patients received no more than 1 and 2 systemic treatment lines, respectively. The 4-year overall survival was 6%, and the median follow-up was 18.6 months. The objective response rate was 55% after the first line of treatment with a median progression-free survival (PFS) of 6.18 months and 12% after the second line with a median PFS of 6.51 months. Grade 3 and 4 adverse events were observed for 33% of patients.

CONCLUSION

Our study confirms a very poor prognosis of stage IV cSCC and a poor response to conventional therapies, indicating that the stage IV cSCC patient population remains with unmet medical needs.

P1838Thrombocytopenia under ECMO and Shear-induced shedding of platelet receptor Glycoprotein-(GP)Ialpha

Background

Several mechanisms are suspected to thrombocytopenia under Extracorporeal Membrane Oxygenation (ECMO) such as platelet-consumption or sepsis. Shedding of glycoprotein-(GP)Ibα is a recently identified mechanism of platelet clearance. ECMO generates high shear stress forces that could impact GPIbα-shedding. We hypothesized that ECMO continuous-flow devices could directly induce thrombocytopenia through shear-induced GPIbα-shedding.

Aims

Determine if ECMO induce GpIb-shedding in vitro and in vivo and determinates the kinetic evolution of platelet-count and GpIb-shedding after patient's implantation.

Methods

Platelet GPIbα-shedding was first investigated in vitro using a high-shear pump loop model. Plasma with normal platelet count (plasma-NPC) was obtained by dilution of platelet-rich plasma obtained from healthy donors in fresh-frozen-plasma. Samples were collected before and after (5, 30, 60 and 180 min) perfusion at 37°C of plasma-NPC at intermediate and high speed (2.6 and 3.6 L min–1 respectively, n=4 each). Platelet count and GPIbα-shedding were next investigated in 20 ECMO patients before/after implantation (WITECMO trial) and in 20 healthy volunteers. The geometric mean-fluorescence-intensity (gMFI) of platelet GPIbα (PE-staining) and GPIX (FITC-staining) was measured with a Navios flow cytometer (Beckman Coulter, Miami, FL). Results are expressed as GPIbα/GPIX gMFI-ratio.

Results

A significant time-dependent loss of GPIbα/GPIX gMFI-ratio was already apparent after 30 min in vitro and was significantly more pronounced at high-speed compared to intermediate-speed (pANOVA<0.001 and p<0.01 at 180 min respectively). GPIbα/GPIX gMFI-ratio was significantly increased in ECMO patients compared to healthy subjects 1- and 24-hour after implantation (p<0.001). A significantly lower platelet count was observed 1 hour after ECMO implantation (−23% vs baseline, p<0.01) with a further significant decrease at 24-hours (−53% vs baseline, p<0.0001).

Figure 1. A. Significant time-dependent loss of platelet GPIbα/GPIX gMFI-ratio (pANOVA <0.001) assessed by flow-cytometry after 30 min of perfusion at 3.6 L/min with a high-shear continuous-flow device in vitro. B. Representative experiment showing the apparition of a platelet sub-population with loss of GPIbα expression after 30 min of perfusion at 3.6 L/minwith a high-shear continuous-flow device in vitro.

[Staphylococcal toxic shock syndrome should be considered in the event of diffuse erythema with fever and shock]

BACKGROUND

Toxic shock syndrome (TSS) was first described by Todd in 1978. The relevant Lancet publication reported 7 cases of children with fever, exanthema, hypotension and diarrhoea associated with multiple organ failure. An association between TSS and use of hyper-absorbent tampons in menstruating women was discovered in the 1980s. Following the market withdrawal of such tampons, TSS virtually disappeared. Herein we report a new case of TSS in a 15-year-old girl.

PATIENTS AND METHODS

A 15-year-old patient was admitted to intensive care for severe sepsis and impaired consciousness associated with diffuse abdominal pain. Dermatological examination revealed diffuse macular exanthema. Laboratory tests showed hepatic cytolysis (ASAT 101 U/L, ALAT 167 U/L, total bilirubin 68μmol/L) and an inflammatory syndrome. Lumbar puncture and blood cultures were sterile while thoraco-abdomino-pelvic and brain scans were normal. The patient was menstruating and had been using a tampon over the previous 24hours. Vaginal sampling and tampon culture revealed TSST-1 toxin-producing S. aureus. Management consisted of intensive care measures and treatment with amoxicillin-clavulanic acid and clindamycin for 10 days.

CONCLUSION

In case of septic shock associated with diffuse macular exanthema a diagnosis of TSS must be envisaged, particularly in menstruating women.

Live-cell imaging of new polyene sterols for improved analysis of intracellular cholesterol transport

Analysis of intracellular cholesterol transport by fluorescence microscopy requires suitable fluorescent analogues of cholesterol. Most existing cholesterol analogues contain lipophilic dyes which can compromise the sterol properties in membranes. An alternative strategy is to introduce additional double bonds into the sterol ring system resulting in intrinsic fluorescence, while at the same time keeping the cholesterol-like properties of the analogues. Existing polyene sterols, such as dehydroergosterol (DHE) or cholestatrienol (CTL), however, contain only three double bonds and suffer from low brightness, significant photobleaching and excitation/emission in the ultraviolet region. Thus, special equipment is required to image such sterols. Here, we describe synthesis, characterization and intracellular imaging of new polyene sterols containing four conjugated double bonds in the sterol ring system. We show that such analogues have red-shifted excitation and emission by ∼20 nm compared to DHE or CTL. The red shift was even more pronounced when preventing keto-enol tautomer equilibration by protecting the 3'-hydroxy group with acetate. We show that the latter analogue can be imaged on a conventional wide field microscope with a DAPI/filipin filter cube. The new polyene sterols show reduced photobleaching compared to DHE or CTL allowing for improved deconvolution microscopy of sterol containing cellular membranes.

[Methods of data selection from the French medical information system program for trauma patient's analysis: Burns and traumatic brain injuries]

BACKGROUND

Data from the French medical information system program in medicine, surgery, obstetrics and dentistry can be adapted in some cases and under certain conditions, to account for hospitalizations for injuries. Two areas have been explored: burn and traumatic brain injury victims.

METHODS

An algorithm selecting data from the Medical information system program was established and implemented for several years for the study of burn victims. The methods of selection of stays for traumatic brain injuries, which are the subject of a more recent exploration, are described.

RESULTS

Production of results in routine on the hospitalization for burns. Expected production of results on the hospitalization for traumatic brain injuries.

CONCLUSION

In both cases, the knowledge obtained from these utilizations of the Medical information system program contributes to epidemiological surveillance and prevention and are useful for health care organization.

[French residents' training in instrumental deliveries: A national survey]

OBJECTIVES

To evaluate French residents in Obstetrics and Gynaecology's training in instrumental deliveries in 2015.

PATIENTS AND METHODS

We conducted a national descriptive survey among 758 residents between December 2014 and January 2015. Respondents were invited by email to specify their University Hospital, their current university term, the number of instrumental deliveries performed by vacuum extractor, forceps or spatulas, and whether they made systematic ultrasound exams before performing the extraction.

RESULTS

Response rate was 34.7 % (n=263). There were important differences between regions in terms of type of instruments used. Vacuum extractor was the most commonly used instrument for instrumental deliveries by French residents (56.9 %), more than forceps (25.2 %) and spatulas (17.9 %). At the end of the residency, all the residents had been trained in instrumental deliveries with at least two instruments.

CONCLUSION

The training of difficult techniques as well as their perfect control is required for instrumental deliveries. Yet, we are forced to note that there are substantial differences in the French residents' training in instrumental deliveries depending on their region. So, teaching at least two techniques seems essential as well as improving the training capacities and standardizing practices. A greater systematization of the teaching of the mechanics and obstetric techniques might be a solution to be considered too.

[Life-threatening Panton-Valentine leukocidin-associated staphylococcal infections in children. A broad spectrum of clinical presentations]

Panton-Valentine leukocidin (PVL) is a major toxic virulence factor secreted by community-acquired methicillin-sensitive or methicillin-resistant Staphylococcus aureus (SA). SA-PVL can be responsible for life-threatening infections in healthy children with a wide spectrum of clinical presentations involving lung, skin, and soft tissues or bones and joints. PVL production should always be considered in severe SA infections. The pediatric medicine community remains poorly informed regarding the therapeutic management of this infection, which should be early and aggressive. Intravenous empiric antibiotics against SA and its toxins must be given with early and sometimes iterative surgical procedures to drain abscesses and to stop bacterial proliferation and necrosis in the tissues. Here, we report the cases of three patients admitted for SA-PVL infections to the pediatric intensive care unit. Initial clinical presentation in the three patients was multifocal osteomyelitis associated with necrotizing pneumonia; severe skin infection with septic shock; and non-necrotic pneumonia with pleural and pericardial effusion. Appropriate treatments resulted in a good outcome in all cases. Following these illustrations, we describe a number of practical key points in the optimal medical and surgical management of severe SA-PVL infections, with a review of the literature.

Tracking image correlation: combining single-particle tracking and image correlation

The interactions and coordination of biomolecules are crucial for most cellular functions. The observation of protein interactions in live cells may provide a better understanding of the underlying mechanisms. After fluorescent labeling of the interacting partners and live-cell microscopy, the colocalization is generally analyzed by quantitative global methods. Recent studies have addressed questions regarding the individual colocalization of moving biomolecules, usually by using single-particle tracking (SPT) and comparing the fluorescent intensities in both color channels. Here, we introduce a new method that combines SPT and correlation methods to obtain a dynamical 3D colocalization analysis along single trajectories of dual-colored particles. After 3D tracking, the colocalization is computed at each particle's position via the local 3D image cross correlation of the two detection channels. For every particle analyzed, the output consists of the 3D trajectory, the time-resolved 3D colocalization information, and the fluorescence intensity in both channels. In addition, the cross-correlation analysis shows the 3D relative movement of the two fluorescent labels with an accuracy of 30 nm. We apply this method to the tracking of viral fusion events in live cells and demonstrate its capacity to obtain the time-resolved colocalization status of single particles in dense and noisy environments.

Paediatric community-acquired septic shock: results from the REPEM network study

INTRODUCTION AND PURPOSE OF THE STUDY: With this study we aimed to describe a "true world" picture of severe paediatric 'community-acquired' septic shock and establish the feasibility of a future prospective trial on early goal-directed therapy in children. During a 6-month to 1-year retrospective screening period in 16 emergency departments (ED) in 12 different countries, all children with severe sepsis and signs of decreased perfusion were included.

RESULTS

A 270,461 paediatric ED consultations were screened, and 176 cases were identified. Significant comorbidity was present in 35.8 % of these cases. Intensive care admission was deemed necessary in 65.7 %, mechanical ventilation in 25.9 % and vasoactive medications in 42.9 %. The median amount of fluid given in the first 6 h was 30 ml/kg. The overall mortality in this sample was 4.5 %. Only 1.2 % of the survivors showed a substantial decrease in Paediatric Overall Performance Category (POPC). 'Severe' outcome (death or a decrease ≥2 in POPC) was significantly related (p < 0.01) to: any desaturation below 90 %, the amount of fluid given in the first 6 h, the need for and length of mechanical ventilation or vasoactive support, the use of dobutamine and a higher lactate or lower base excess but not to any variables of predisposition, infection or host response (as in the PIRO (Predisposition, Infection, Response, Organ dysfunction) concept).

CONCLUSION

The outcome in our sample was very good. Many children received treatment early in their disease course, so avoiding subsequent intensive care. While certain variables predispose children to become septic and shocked, in our sample, only measures of organ dysfunction and concomitant treatment proved to be significantly related with outcome. We argue why future studies should rather be large multinational prospective observational trials and not necessarily randomised controlled trials.