Sustained xanthophyll pigments-related photoprotective NPQ is involved in photoinhibition in the haptophyte Tisochrysis lutea.

Dynamic xanthophyll cycle (XC) related non-photochemical quenching (NPQd, also called qE) is present in most phototrophs. It allows dissipating excess light energy under adverse growing conditions. Generally, NPQd rapidly reverses for photosynthesis to resume when light intensity decreases back toward optimal intensity. Under certain environmental conditions and/or in some species, NPQ can be strongly sustained (NPQs showing hours-to-days relaxation kinetics). Tisochrysis lutea is a South Pacific haptophyte phytoplankton with a strong potential for aquaculture and biotechnology applications. It was previously reported to show a surprisingly low NPQd capacity while synthesizing large amounts of diatoxanthin (Dt), a pigment involved in the XC. In order to better understand this paradox, we investigated the characteristics of NPQ in T. lutea under various growth conditions of light and nutrient availability (different photoperiods, low and high light, nutrient starvations). We found a strong NPQs, unmeasurable with usual fluorometry protocols. Along with confirming the involvement of Dt in both NPQd and NPQs (by using the dithiothreitol inhibitor), we highlighted a strong relationship between Dt and the maximum quantum yield of photochemistry (Fv/Fm) across growing conditions and during relaxation experiments in darkness. It suggests that changes in Fv/Fm, usually attributed to the 'photoinhibitory' quenching (qI), are simultaneously largely impacted by photoprotective NPQ. The overlap of xanthophyll pigments-related photoprotective NPQ with several other mechanisms involved in the cell response (Photosystem II photoinactivation, changes in pigments composition, and detoxification by antioxidants) to energy unbalance is further discussed. Our findings question both how widespread NPQs is in the global ocean, particularly in nutrient starved environments (oligotrophic waters) and situations (post-bloom), and the use of adapted active fluorescence protocols (i.e. with extended NPQ relaxation period prior to measurement).

[Cutaneous manifestation of lymphoid variant of hypereosinophilic syndrome: One case]. / Un cas de manifestation cutanée d'un syndrome hyperéosinophilique lymphoïde.

INTRODUCTION: Lymphoid hypereosinophilic syndrome (HES) is a reactive HES, related to the presence of an abnormal circulating T cell clone. Cutaneous manifestations are frequent and sometimes inaugural, however few studies describe them specifically. CASE REPORT: We report the case of a 63-year old patient, in good general condition, with no previous history and taking no treatment, who was being followed for non-specific skin lesions. Blood and skin examinations showed hypereosinophilia, the presence of an aberrant CD3-CD4+ phenotype and a positive T-clonality test. There was no differential diagnosis or argument for a systemic lymphoma. CONCLUSION: Cutaneous manifestations of lymphoid HES are variable, non-specific, and may differ according to lymphocyte phenotype. The discovery of SHE requires an extension workup and the risk of evolution towards a systemic lymphoma justifies a close surveillance. Treatment is adapted to the severity of the symptoms.

Proactive treatment in childhood psoriasis.

Psoriasis affects 0.5% of children. The current therapeutic arsenal includes local treatments, phototherapies and systemic treatments (conventional systemic therapy and biotherapy), which, in most cases, are sufficient to control this skin disease. Subsequent management of these children should focus on maintaining therapeutic efficacy and preventing relapse by reducing any treatment-related toxicity in order to improve their quality of life. It would therefore appear useful to adopt a "proactive" attitude. To be proactive is to anticipate disease progression in order to limit both the severity and the incidence of new flare-ups. This approach must be distinguished from reactive support. Based on our experience of atopic dermatitis and data on adult psoriasis, in the absence of publications specific to childhood-onset psoriasis, herein we propose to provide an overview of this proactive approach in paediatric psoriasis. This proactive management approach concerns four key precepts: therapeutic education: explanation of the disease, its pathophysiology and the various possible therapeutic approaches; prevention of factors triggering flare-ups or worsening psoriatic infections, such as stress, trauma, diet (mainly reduction of obesity); a proactive approach to topical therapy: skin hygiene and use of emollients, but also limitation of active therapies, use of dosing intervals and "weekend therapy" to reduce the risk of relapse; a proactive approach to systemic therapies: improved therapeutic safety, reduced cumulative doses, through reduced doses, use of dosing intervals and weekend therapy. Care for children with psoriasis must be comprehensive and include their environment. The concept of "proactive" treatment in childhood-onset psoriasis can help limit the duration and severity of flare-ups while improving quality of life. Simple measures can in fact ensure effective maintenance of treatments over the long term.

[Severity scores for childhood psoriasis: A systematic literature review]. / Scores de sévérité dans le psoriasis de l'enfant : revue systématique de la littérature.

BACKGROUND: Psoriasis affects 0.5 to 1 % of children in Europe. It has a significant impact on quality of life. Recently, systemic treatments have been licensed for children with moderate-to-severe psoriasis. While scores to assess the severity of the disease are thus important for the management of these children, there is no standardization or consensus concerning their use in childhood psoriasis. The aim of this study was to examine the use of clinical severity scores and quality of life in children with psoriasis. PATIENTS AND METHODS: A systematic literature review was conducted on PubMed and Embase. Further research was carried out using the bibliographic references in selected articles. The following keywords were used: "psoriasis" with "pediatric", "childhood", "infant", "child" or "adolescent", and "Severity of Illness Index", "sickness impact profile", "quality of life", "index", "measure" or "score". A first selection was made from the titles and abstracts of the selected articles. RESULTS: After evaluating 1712 articles on Medline and 233 on Embase, 78 were finally selected. The Psoriasis Area Severity Index (PASI: 74.4 %) was the most frequently found score followed by the Body Surface Area (BSA: 48.7 %) and the Physician's Global Assessment (PGA: 29.5 %). Recourse to systemic therapies and failure of topical treatments were also used as severity criteria. Over half the studies did not define a severity threshold. We also observed extensive heterogeneity in the definition of psoriasis severity. The same scores were often used regardless of psoriasis type or patient age. Regarding quality of life, most studies used the Children's Dermatology Life Quality Index (CDLQI: 23.1 %) and DLQI (5.1 %). Non-specific quality-of-life scores for psoriasis were also used, such as the Pediatric Quality of Life Inventory (Peds-QL: 6.4 %) and Skindex (2.6 %). Here again, no severity threshold was defined for these scores. DISCUSSION: Severity scores are chiefly used by analogy with adults but without validation in the pediatric population. They do not consider pediatric specificities such as progression of BSA according to age, clinical aspect, clinical types, etc. Severity thresholds are rarely defined in children, whether in terms of clinical score or quality of life. This can constitute a limitation in terms of both prescription of systemic treatments and comparison between different studies. Our study demonstrates the need to validate severity and quality-of-life scores and to define child-specific thresholds.

Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms.

Photoacclimation by strains of Haslea "blue" diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction-recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m-2 s-1 photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σPSII') or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σPSII' in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. QA- oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction-recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment.

Electrochemotherapy guided by intraoperative fluorescence imaging for the treatment of inoperable peritoneal micro-metastases.

Surgery is often the first therapeutic indication in cancer. Patient survival essentially depends on the completeness of tumor resection. This is a major challenge, particularly in patients with peritoneal carcinomatosis (PC), where tumors are widely disseminated in the large peritoneal cavity. These small tumors can be difficult to visualize and are often positioned in delicate locations, further increasing the risk of producing serious tissue/organ damage during their ablation. We propose an innovative therapeutic approach based on intraoperative fluorescence (IF) guided electrochemotherapy (ECT) for the treatment of peritoneal micro-metastases. ECT combines the effects of tissue electro-permeabilization (EP) with the administration of an antimitotic agent (bleomycin) that has poor permeability across intact membranes. IF significantly improves the detection of small tumor lesions. ECT is clinically validated for the treatment of cutaneous tumors in animals and humans, but this is the first time that it has been used along with IF imaging for the targeted treatment of peritoneal metastases in a preclinical model. We set up a murine model of PC that develops secondarily to the resection of a distant primary tumor. Tumor growth and metastasis were finely monitored by non-invasive multimodal imaging (bioluminescence and 3D fluorescence/microCT). Once metastases were detected, mice were randomized into three groups: the ECT group (bleomycin injected intravenously followed by EP) and 2 control groups (bleomycin alone and EP alone). Twenty four hours after the intravenous injection of the tumor targeting agent Angiostamp™700, mice in all groups underwent an abdominal surgery for metastases exploration assisted by fluorescence imaging with the Fluobeam®700 portative device. EP was applied to every nodule detected by IF, except in the bleomycin control group. After surgery, the metastatic invasion was tracked by bioluminescence imaging. In mice treated with bleomycin or EP alone, the metastatic load progressed very rapidly and mice showed no significant difference in lifespan compared to non-operated mice (median lifespan: 27days vs. 25days, respectively). In contrast, the mice treated with ECT displayed a decreased metastatic load and an increased survival rate (median lifespan: 34days). These results provide evidence that IF guided ECT is an effective approach for the treatment of inoperable intraperitoneal micro-metastases.

Assessment of a polyelectrolyte multilayer film coating loaded with BMP-2 on titanium and PEEK implants in the rabbit femoral condyle.

UNLABELLED: The aim of this study was to evaluate the osseointegration of titanium implants (Ti-6Al-4V, noted here TA6V) and poly(etheretherketone) PEEK implants induced by a BMP-2-delivering surface coating made of polyelectrolyte multilayer films. The in vitro bioactivity of the polyelectrolyte film-coated implants was assessed using the alkaline phosphatase assay. BMP-2-coated TA6V and PEEK implants with a total dose of 9.3µg of BMP-2 were inserted into the femoral condyles of New Zealand white rabbits and compared to uncoated implants. Rabbits were sacrificed 4 and 8weeks after implantation. Histomorphometric analyses on TA6V and PEEK implants and microcomputed tomography on PEEK implants revealed that the bone-to-implant contact and bone area around the implants were significantly lower for the BMP-2-coated implants than for the bare implants. This was confirmed by scanning electron microscopy imaging. This difference was more pronounced at 4weeks in comparison to the 8-week time point. However, bone growth inside the hexagonal upper hollow cavity of the screws was higher in the case of the BMP-2 coated implants. Overall, this study shows that a high dose of BMP-2 leads to localized and temporary bone impairment, and that the dose of BMP-2 delivered at the surface of an implant needs to be carefully optimized. STATEMENT OF SIGNIFICANCE: The presentation of growth factors from material surfaces currently presents significant challenges in academia, clinics and industry. Applying osteoinductive factors to different types of implants, made of metals or polymers, may improve bone repair in difficult situations. Here, we show the effects of an osteoinductive coating made of polyelectrolyte multilayer films on two widely used materials, titanium TA6V alloys and PEEK implants, which were implanted in the rabbit femoral condyle. We show that a too high dose of BMP-2 delivered from the screw surface has a negative short-term effect on bone regeneration in close vicinity of the screw surface. In contrast, bone formation was increased at early times in the empty spaces around the screw. These results highlight the need for future dose-dependence studies on bone formation in response to osteoinductive coatings.

Microspatial variability in community structure and photophysiology of calcified macroalgal microbiomes revealed by coupling of hyperspectral and high-resolution fluorescence imaging.

Calcifying coralline macroalgae provide biogenic habitats colonised by epiphytic microalgae that contribute significantly to community productivity. Georeferenced hyperspectral and high-resolution fluorescence imaging were coupled to microspatially mapped community composition and relative biomass of macroalgal host and epiphyte microalgal groups, and their weighted contributions to productivity within host fronds of Corallina officinalis on upper and lower zones of a rocky shore were determined. Lower shore epiphytes were dominated by filamentous diatoms (Bacillariophyta), confined to the apex of the frond structure, which were low light acclimated but retained a high capacity for photoprotective down regulation and contributed up to 51% of total community productivity. Upper shore epiphytes were dominated by green algae (Chlorophyta) and single-celled diatoms (principally Cocconeis spp.), which were high light acclimated but present at far lower relative biomass and contributed negligibly to productivity. The host, C. officinalis was the main primary producer. Variation in light environment resulting from differences in shore height and shading within the host macroalga, likely play a large role in determining patterns in epiphyte community structure, biomass and productivity observed. Additionally, microspatial gradients in photophysiological parameters along the host macroalga likely resulted from age-dependent variation in pigments as well as the gradient in light environment.

Noninvasive and quantitative assessment of in vivo fetomaternal interface angiogenesis using RGD-based fluorescence.

Angiogenesis is a key process for proper placental development and for the success of pregnancy. Although numerous in vitro methods have been developed for the assessment of this process, relatively few reliable in vivo methods are available to evaluate this activity throughout gestation. Here we report an in vivo technique that specifically measures placental neovascularization. The technique is based on the measurement of a fluorescent alpha v beta 3 (αvß3) integrin-targeting molecule called Angiolone-Alexa-Fluor 700. The αvß3 integrin is highly expressed by endothelial cells during the neovascularization and by trophoblast cells during their invasion of the maternal decidua. Angiolone was injected to gravid mice at 6.5 and 11.5 days post coitus (dpc). The fluorescence was analyzed one day later at 7.5 and 12.5 dpc, respectively. We demonstrated that (i) Angiolone targets αvß3 protein in the placenta with a strong specificity, (ii) this technique is quantitative as the measurement was correlated to the increase of the placental size observed with increasing gestational age, and (iii) information on the outcome is possible, as abnormal placentation could be detected early on during gestation. In conclusion, we report the validation of a new noninvasive and quantitative method to assess the placental angiogenic activity, in vivo.

[Life-threatening event]. / Malaise grave du nourrisson.

Life-threatening event of infant is rare, but represents for parents or his family, a greater distress, because life of child seems threatened quickly. It is a savage event, that usually affects vital parameters of infant under six months' age. Knowing how to use the first gestures of aid before arrival of voluntary firemen, then that of Service mobile d'urgence et de réanimation (SMUR) team, who have been mobilized quickly after calling 15 (French 911), is the main aim of the practitioner. The hospitalization is obligatory to oversee infant (recurrence always possible) on clinical plan and adequate equipment in order to find the aetiology which caused the life-threatening event. In spite of deep explorations, sometimes aetiology remains unknown.

[A move meat beginning...and evolutive]. / Un début de repas mouvementé...et évolutif.

Food allergies are more and more numerous, and frequent in children at all ages. At any moment, a clinical manifestation, quickly evolutive and alarming, must need the help call at phone 15, and the intervention of a medical team of SMUR. The departmental, free, cell to 15 for all medical emergencies note a regular increase of these specific calls since ten years, as this following case report shows it.

Quantitative and qualitative evaluation of phytoplankton communities by trichromatic chlorophyll fluorescence excitation with special focus on cyanobacteria.

We present results that were obtained with a newly developed fluorometer, the 'PhytoSensor'. They are based on multi-wavelength excitation of chlorophyll fluorescence to detect the phytoplankton biomass and to identify main taxons (among cyanobacteria, green and brown microalgae). A method to evaluate the photosynthetic potential of the phytoplankton was established. Attention was focused on the measurement of the cyanobacterial biomass. A modelling to distinguish between the two spectral groups (blue and red) of cyanobacteria as a function of their pigments and physiological status is proposed. The main innovation of the device results in the recording of the fluorescence induction kinetics of the phytoplankton to confirm and refine the evaluation of the taxonomic composition. The PhytoSensor abilities were compared with pigment analysis, commercial fluorometers, particle and microscopic counting and identification. The PhytoSensor has been used with success to monitor the dynamics of phytoplankton in drinking-water supply reservoirs in Southeast Asia.

[Domestic animals and accidents in children]. / Animaux domestiques et accidents chez l'enfant.

Young French children have 45,000,000 domestic pets, cats and dogs being widely prevalent (40%). Injuries due to domestic animals, especially bites, in particular from dogs, represent 1.9% of all children's injuries. On the quality of first aid in the field, i.e., whether the treatment is the first line in surgical specialized service or not, if it is a vital emergency, will depend the possibility of immediate complications, which include local superinfection (15%), functionals and further aesthetic sequelae. Some injuries due to large animals carry a polytraumatism, which should be treated like all polytraumatisms, whatever the aetiology. Learning to know and respect animals and their needs should remain the priority of families to avoid unexpected injury. Families also need to take charge of the responsible animal.

[The pediatrician's emergency box]. / Trousse d'urgence en pédiatrie.

Every private pediatrician must be available to respond at pediatrics emergencies over thinking action in acute situations, which can quickly worsen. With his knowledge and a vigorous experience on field, he must possess minimum material and drugs, put in an emergency box to talking face up to distress's situations really or feeling like that by parents or in close circle of child. Private pediatrician is a link of a care chain and/or assistance, to be waiting that wounded arrive to hospital emergency unit or in a specialized service, when he will be taken in charge by SMUR team.

[Newborn asphyxia at term during delivery]. / Volume de recrutement, charge de travail et morbidité liés aux asphyxies per-partum à terme pour les services mobiles d'urgence et de réanimation (SMUR) pédiatriques.

UNLABELLED: Recruitment, work load and morbidity linked to newborn asphyxia during delivery at term: a study from Pediatric Mobile Intensive Care Units. OBJECTIVE: In a population of term neonates transported by the mobile intensive care units (MICU), we aimed to determine the incidence of neonates with anoxic-ischemic encephalopathy related to asphyxia, to analyze in this population the difficulties of management, and to try to identify which of these newborns require new therapeutic strategies. METHODS: This retrospective study was performed over a 2-year period (2000 and 2001) in 3 paediatric MICU from the Ile de France area. During this period, 7,648 infants were transported including 3,301 newborns of more than 36 weeks of gestational age and less than 72 hours of life. These neonates came from 73 different hospitals. Among these 3,301 infants, 237 neonates (124 boys and 113 girls) with anoxic-ischemic encephalopathy related to asphyxia were selected in the present study. Inclusion criteria were association of one obligatory criterion of fetal distress during delivery and at least one criterion of neonatal asphyxia or one criterion of anoxic-ischemic encephalopathy. Data were compiled and analyzed with Epidata package and Epi info package, respectively. RESULTS: These 237 neonates with anoxic-ischemic represented 12% of MICU activity at the same gestational and postnatal ages. The mean gestational age was 39.5 + 1.5 weeks. The mean birth weight was 3,188 + 559 g. More than 50% of these neonates were born in level I maternities. Fifty-three percent of the infants were born by caesarean section. Eighty-three percent of the neonates had an Apgar score at 1 minute <3. Eighty-eight percent of the neonates received resuscitation care at 5 minutes of life and 34% of these had an Apgar score at 10 minutes <5. In 50% of the cases, the MICUs arrived at the maternity of delivery within 1 h 45 min of life and transportation of the neonates was completed after 3 hours of life. The neonates were transported to an intensive care unit in 88% of the cases (half to a polyvalent intensive care unit and half to a neonatal intensive care unit). Forty-four percent of transported neonates had no encephalopathy, 30% had a severe encephalopathy or seizures, 27% had multiple organ failure. Mortality reached 28% and encephalopathy accounted for two thirds of these deaths. Neonates who arrived in pediatric care units after 3 hours of life had more severe morbidity than neonates who arrived before 3 hours of life. CONCLUSION: Pediatric MICUs transport the most severely affected neonates. The initial clinical state is critical, and systemic and neurological complications are frequent and severe. Calls to the MICU should be made earlier in order to enable a better impact of new neuroprotective strategies.

In diatoms, a transthylakoid proton gradient alone is not sufficient to induce a non-photochemical fluorescence quenching.

Non-photochemical fluorescence quenching (NPQ) in diatoms is associated with a xanthophyll cycle involving diadinoxanthin (DD) and its de-epoxidized form, diatoxanthin (DT). In higher plants, an obligatory role of de-epoxidized xanthophylls in NPQ remains controversial and the presence of a transthylakoid proton gradient (DeltapH) alone may induce NPQ. We used inhibitors to alter the amplitude of DeltapH and/or DD de-epoxidation, and coupled NPQ. No DeltapH-dependent quenching was detected in the absence of DT. In diatoms, both DeltapH and DT are required for NPQ. The binding of DT to protonated antenna sites could be obligatory for energy dissipation.

[Severe bacterial infections in children. Survey by the pediatric mobile intensive care unit AP/HP in the Ile-de-France area]. / Infections bactériennes graves de l'enfant. Enquête des SMUR pédiatriques AP/HP de l'Ile-de-France (de 1998 au 1er quadrimestre 2001).

This study involves 106 infants (neonatal period ruled out), victims of severe bacterial infections managed from 1st january 1998 to 30 April 2001 by the four paediatric Mobile Intensive Care Unit (P.M.I.C.U.) teams AP-HP in Ile-de-France area. 46.2% of the whole infants are primary interventions (home, medical room, airport) and primary-secondary interventions (hospital emergencies) whereas 53.8% are related to secondary transports of infants who have been hospitalized and suffered from severe bacterial disorders complicating their original disease. 51% are meningitidis infections, rather due to streptococcus pneumoniae and meningococcis, associated with severe infectious purpura. 20.75% are toxic shock syndromes in patients suffering from chronic affections (sickle cell anemia), acquired or congenital immunodeficiencies; 19.8% of the cases are severe bacterial pneumonia (staphylococcal pleuro-pneumopathies, bordetella pertussis cough) or surinfected viral infections (VRS bronchiolitis, pneumonia due to mycoplasma pneumoniae and para-influenzae III). Authors study various characteristics of the two patient's groups, their immediate management by local medical team and by the P.M.I.C.U. team, their early term outcome. 65% of children recovered apparently without sequelae, 19% died, and 16% healed but with significant sequelaes, notably neurological damage. Meningitidis due to Streptococcus pneumoniae are particularly severe, because of their prognostic (10 deaths, 8 severe sequelae among the 26 cases). These observations prompted us to recommend early immunization of infants at 2-3 months post natal age by the new vaccine conjugated up to 7 valences such as "Prevenar". If this vaccine have been available for this patient series, may be avoided 8 deaths, 7 severe sequelae, with 1 septic shock syndrome due to streptococcus pneumoniae and another serious infection in a homozygous sickle cell disease.