Melanoma is a malignant tumour with a poorer prognosis in stage III and IV patients. Development of effective therapies for the treatment of advanced melanoma has led to an improvement in survival. Furthermore, the French population is ageing, and treatment of melanoma in this population has several specific limitations.
View Article and Find Full Text PDFDiatoms are a diverse group of phytoplankton usually dominating areas characterized by rapidly shifting light conditions. Because of their high growth rates and interesting biochemical profile, their biomass is considered for various commercial applications. This study aimed at identifying strains with superior growth in a photobioreactor (PBR) by screening the natural intraspecific diversity of ecotypes isolated from different habitats.
View Article and Find Full Text PDFIt has long been hypothesized that benthic motile pennate diatoms use phototaxis to optimize photosynthesis and minimize photoinhibitory damage by adjusting their position within vertical light gradients in coastal benthic sediments. However, experimental evidence to test this hypothesis remains inconclusive, mainly due to methodological difficulties in studying cell behavior and photosynthesis over realistic spatial microscale gradients of irradiance and cell position. In this study, a novel experimental approach was developed and used to test the hypothesis of photosynthesis optimization through motility, based on the combination of single-cell in vivo chlorophyll fluorometry and microfluidic chips.
View Article and Find Full Text PDFDiatoms, the main eukaryotic phytoplankton of the polar marine regions, are essential for the maintenance of food chains specific to Arctic and Antarctic ecosystems, and are experiencing major disturbances under current climate change. As such, it is fundamental to understand the physiological mechanisms and associated molecular basis of their endurance during the long polar night. Here, using the polar diatom Fragilariopsis cylindrus, we report an integrative analysis combining transcriptomic, microscopic and biochemical approaches to shed light on the strategies used to survive the polar night.
View Article and Find Full Text PDFDynamic 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.
View Article and Find Full Text PDFIn aquatic ecosystems, microalgae are exposed to light fluctuations at different frequencies due to daily and seasonal changes. Although concentrations of herbicides are lower in Arctic than in temperate regions, atrazine and simazine, are increasingly found in northern aquatic systems because of long-distance aerial dispersal of widespread applications in the south and antifouling biocides used on ships. The toxic effects of atrazine on temperate microalgae are well documented, but very little is known about their effects on Arctic marine microalgae in relation to their temperate counterparts after light adaptation to variable light intensities.
View Article and Find Full Text PDFPolar ecosystems play an important role in global primary production. Microalgae have adaptations that enable them to live under low temperature environments where irradiance and day length change drastically. Their adaptations, leading to different ecophysiological characteristics relative to temperate species, could also alter their sensitivity to pollutants such as pesticides.
View Article and Find Full Text PDFCarotenoid xanthophyll pigments are receiving growing interest in various industrial fields due to their broad and diverse bioactive and health beneficial properties. Fucoxanthin (Fx) and the inter-convertible couple diadinoxanthin-diatoxanthin (Ddx+Dtx) are acknowledged as some of the most promising xanthophylls; they are mainly synthesized by diatoms (Bacillariophyta). While temperate strains of diatoms have been widely investigated, recent years showed a growing interest in using polar strains, which are better adapted to the natural growth conditions of Nordic countries.
View Article and Find Full Text PDFIntroduction: 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.
The effects of herbicide diuron on photosynthesis and vertical migration of intertidal microphytobenthos (MPB) assemblages were investigated using chlorophyll fluorometry. The results shown diuron ≤ 60 μg L had no obvious effect on MPB vertical migration during 24 h indicated by consistent rhythm. Low concentration of 10 μg L diuron had no significant influence on MPB photosynthesis throughout, however, high concentrations of 40, 50, and 60 μg L had significant impacts exhibited by decreased parameters of maximum relative electron transport rate (rETR), maximal PS II quantum yield (F/F) and non-photochemical quenching (NPQ).
View Article and Find Full Text PDFmolecular imaging in preclinical animal models is a tool of choice for understanding the pathophysiological mechanisms involved in cancer development and for conducting drug development research. Moreover, combining several imaging modalities can provide multifaceted, complementary and cross-validated information. Photoacoustic imaging (PAI) is a promising imaging modality that can reflect blood vasculature and tissue oxygenation as well as detect exogenous molecules, but one shortcoming of PAI is a lack of organic photoacoustic contrast agents capable of providing tumor contrast.
View Article and Find Full Text PDFDiatoms are major primary producers in polar environments where they can actively grow under extremely variable conditions. Integrative modeling using a genome-scale model (GSM) is a powerful approach to decipher the complex interactions between components of diatom metabolism and can provide insights into metabolic mechanisms underlying their evolutionary success in polar ecosystems. We developed the first GSM for a polar diatom, , which enabled us to study its metabolic robustness using sensitivity analysis.
View Article and Find Full Text PDFBackground: Cutaneous squamous cell carcinoma (cSCC) is the second most frequent non-melanoma skin cancer. Treatment options for inoperable advanced cSCC cases are limited. The efficacy of anti-programmed cell death-1 (PD-1) monoclonal antibodies (mAb) has been reported recently in some patients with cSCC.
View Article and Find Full Text PDFXanthophyll cycle-related nonphotochemical quenching (NPQ), which is present in most photoautotrophs, allows dissipation of excess light energy. Xanthophyll cycle-related NPQ depends principally on xanthophyll cycle pigments composition and their effective involvement in NPQ. Xanthophyll cycle-related NPQ is tightly controlled by environmental conditions in a species-/strain-specific manner.
View Article and Find Full Text PDFPsoriasis 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.
View Article and Find Full Text PDFDiatoms possess an impressive capacity for rapidly inducible thermal dissipation of excess absorbed energy (qE), provided by the xanthophyll diatoxanthin and Lhcx proteins. By knocking out the Lhcx1 and Lhcx2 genes individually in Phaeodactylum tricornutum strain 4 and complementing the knockout lines with different Lhcx proteins, multiple mutants with varying qE capacities are obtained, ranging from zero to high values. We demonstrate that qE is entirely dependent on the concerted action of diatoxanthin and Lhcx proteins, with Lhcx1, Lhcx2 and Lhcx3 having similar functions.
View Article and Find Full Text PDFBreast cancer with bone metastasis is essentially incurable with current anticancer therapies. The bone morphogenetic protein (BMP) pathway is an attractive therapeutic candidate, as it is involved in the bone turnover and in cancer cell formation and their colonization of distant organs such as the bone. We previously reported that in breast cancer cells, the ZNF217 oncogene drives BMP pathway activation, increases the metastatic growth rate in the bone, and accelerates the development of severe osteolytic lesions in mice.
View Article and Find Full Text PDFAnn Dermatol Venereol
December 2019
Background: Psoriasis affects 0.5 to 1 % of children in Europe. It has a significant impact on quality of life.
View Article and Find Full Text PDF