Implémentation et vérification de la méthode zonale à coefficients d'absorption multiples

Presentation available online at http://www.sft.asso.fr/Local/sft/dir/user-3775/documents/actes/congres_2011/Communications/167.pdfNational audienceLa méthode zonale à coefficients d'absorption multiples (MACZM) pour la modélisation des facteurs de transferts radiatifs dans les milieux transparents et semi-transparents est implémentée et validée numériquement. Les calculs sont améliorés par l'utilisation de réseaux de neurones artificiels. Une autre méthode efficace de calcul des facteurs de transferts radiatifs, la méthode des flux plans, est aussi décrite. Les deux méthodes sont appliquées simultanément pour le calcul des facteurs d'échanges radiatifs dans un four de réchauffage sidérurgique de brames d'acier et les résultats sont comparés. La validité deMACZM est ainsi démontrée et des temps de calcul réduits de plus de cent fois sont obtenus

Essential oils modulate gene expression and ochratoxin a production in Aspergillus carbonarius

Ochratoxin A (OTA) is a mycotoxin, mainly produced on grapes by Aspergillus carbonarius, that causes massive health problems for humans. This study aims to reduce the occurrence of OTA by using the ten following essential oils (E.Os): fennel, cardamom, anise, chamomile, celery, cinnamon, thyme, taramira, oregano and rosemary at 1 µL/mL and 5 µL/mL for each E.O. As a matter of fact, their effects on the OTA production and the growth of A. carbonarius S402 cultures were evaluated, after four days at 28 C on a Synthetic Grape Medium (SGM). Results showed that A. carbonarius growth was reduced up to 100%, when cultured with the E.Os of cinnamon, taramira, and oregano at both concentrations and the thyme at 5 µL/mL. As for the other six E.Os, their effect on A. carbonarius growth was insignificant, but highly important on the OTA production. Interestingly, the fennel E.O at 5 µL/mL reduced the OTA production up to 88.9% compared to the control, with only 13.8% of fungal growth reduction. We further investigated the effect of these E.Os on the expression levels of the genes responsible for the OTA biosynthesis (acOTApks and acOTAnrps along with the acpks gene) as well as the two regulatory genes laeA and vea, using the quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) method. The results revealed that these six E.Os reduced the expression of the five studied genes, where the ackps was downregulated by 99.2% (the highest downregulation in this study) with 5 µL/mL of fennel E.O. As for the acOTApks, acOTAnrps, veA and laeA, their reduction levels ranged between 10% and 96% depending on the nature of the E.O and its concentration in the medium

Exosomes on the border of species and kingdom intercommunication

Centro de Medicina RegenerativaOver the last decades exosomes have become increasingly popular in the field of medicine. While until recently they were believed to be involved in the removal of obsolete particles from the cell, it is now known that exosomes are key players in cellular communication, carrying source-specific molecules such as proteins, growth factors, miRNA/mRNA, among others. The discovery that exosomes are not bound to intraspecies interactions, but are also capable of interkingdom communication, has once again revolutionized the field of exosomes research. A rapidly growing body of literature is shedding light at novel sources and participation of exosomes in physiological or regenerative processes, infection and disease. For the purpose of this review we have categorized 6 sources of interest (animal products, body fluids, plants, bacteria, fungus and parasites) and linked their innate roles to the clinics and potential medical applications, such as cell-based therapy, diagnostics or drug delivery

Antifungal and Antiochratoxigenic Activities of Essential Oils and Total Phenolic Extracts: A Comparative Study

This study is intended to prevent ochratoxin A (OTA) production by Aspergillus carbonarius S402 using essential oils (EOs) and total phenolic compounds extracted from plants and herbs. The EOs used in this study are the following: bay leaves, cumin, fenugreek, melissa, mint, and sage. As for the phenolic compounds, they were extracted from bay leaves, cumin, fenugreek, melissa, mint, sage, anise, chamomile, fennel, rosemary, and thyme. The experiments were conducted on Synthetic Grape Medium (SGM) medium at 28 °C for 4 days. OTA was extracted from the medium with methanol and quantified using HPLC (High Performance Liquid Chromatography). Results showed that EOs had a greater impact than the total phenolic extracts on the OTA production. Reduction levels ranged between 25% (sage) and 80% (melissa) for the EOs at 5 µL mL-1, and 13% (thyme) and 69% (mint) for the phenolic extracts. Although they did not affect the growth of A. carbonarius, total phenolic extracts and EOs were capable of partially reducing OTA production. Reduction levels depended on the nature of the plants and the concentration of the EOs. Reducing OTA with natural extracts could be a solution to prevent OTA production without altering the fungal growth, thus preserving the natural microbial balance

Ability of Soil Isolated Actinobacterial Strains to Prevent, Bind and Biodegrade Ochratoxin A

Ochratoxin A (OTA) is one of the most important mycotoxins, and contaminates several agricultural products, particularly cereals, grapes, maize, barley, spices and coffee. The aim of this project was to reduce the levels of OTA by supplementing the artificially contaminated solutions with seven strains of actinobacteria (AT10, AT8, SN7, MS1, ML5, G10 and PT1) in order to evaluate their capacity for binding and metabolizing the OTA, as well as their ability to reduce the expression of the genes responsible for its production in A. carbonarius. In the first part of this study, we evaluated the capacity of Streptomyces strains for binding OTA on their surfaces after 0, 30 and 60 min of incubation with PBS solution supplemented with OTA. In the second part, we tested the ability of these strains, as well as their supernatants, to detoxify the ISP2 medium. Finally, we studied the effect of the Streptomyces cocultured with Aspergillus carbonarius on the expression of OTA biosynthesis genes. Results showed that, among the strains co-cultured with A. carbonarius, the strain G10 was able to reduce the expression of acpks, acOTApks, acOTAnrps and vea genes, thus reducing OTA from solid PDA medium to 13.50% of reduction. This strain was remarkably able to detoxify and bind OTA up to 47.07%. Strain AT8 was stronger in detoxifying OTA (52.61%), but had no significant effect on the studied gene expression

Artificial Mitochondria Transfer: Current Challenges, Advances, and Future Applications

The objective of this review is to outline existing artificial mitochondria transfer techniques and to describe the future steps necessary to develop new therapeutic applications in medicine. Inspired by the symbiotic origin of mitochondria and by the cell’s capacity to transfer these organelles to damaged neighbors, many researchers have developed procedures to artificially transfer mitochondria from one cell to another. The techniques currently in use today range from simple coincubations of isolated mitochondria and recipient cells to the use of physical approaches to induce integration. These methods mimic natural mitochondria transfer. In order to use mitochondrial transfer in medicine, we must answer key questions about how to replicate aspects of natural transport processes to improve current artificial transfer methods. Another priority is to determine the optimum quantity and cell/tissue source of the mitochondria in order to induce cell reprogramming or tissue repair, in both in vitro and in vivo applications. Additionally, it is important that the field explores how artificial mitochondria transfer techniques can be used to treat different diseases and how to navigate the ethical issues in such procedures. Without a doubt, mitochondria are more than mere cell power plants, as we continue to discover their potential to be used in medicine.</jats:p

Human CD34+ CD133+ Hematopoietic Stem Cells Cultured with Growth Factors Including Angptl5 Efficiently Engraft Adult NOD-SCID Il2rγ−/− (NSG) Mice

Increasing demand for human hematopoietic stem cells (HSCs) in clinical and research applications necessitates expansion of HSCs in vitro. Before these cells can be used they must be carefully evaluated to assess their stem cell activity. Here, we expanded cord blood CD34+ CD133+ cells in a defined medium containing angiopoietin like 5 and insulin-like growth factor binding protein 2 and evaluated the cells for stem cell activity in NOD-SCID Il2rg−/− (NSG) mice by multi-lineage engraftment, long term reconstitution, limiting dilution and serial reconstitution. The phenotype of expanded cells was characterized by flow cytometry during the course of expansion and following engraftment in mice. We show that the SCID repopulating activity resides in the CD34+ CD133+ fraction of expanded cells and that CD34+ CD133+ cell number correlates with SCID repopulating activity before and after culture. The expanded cells mediate long-term hematopoiesis and serial reconstitution in NSG mice. Furthermore, they efficiently reconstitute not only neonate but also adult NSG recipients, generating human blood cell populations similar to those reported in mice reconstituted with uncultured human HSCs. These findings suggest an expansion of long term HSCs in our culture and show that expression of CD34 and CD133 serves as a marker for HSC activity in human cord blood cell cultures. The ability to expand human HSCs in vitro should facilitate clinical use of HSCs and large-scale construction of humanized mice from the same donor for research applications.Singapore-MIT Alliance for Research and Technology ( Infectious Diseases research grant

Valorization of wine‐making by‐products’ extracts in cosmetics

The increased demand for conscious, sustainable and beneficial products by the consumers has pushed researchers from both industries and universities worldwide to search for smart strategies capable of reducing the environmental footprint, especially the ones connected with industrial wastes. Among various by-products, generally considered as waste, those obtained by winemaking industries have attracted the attention of a wide variety of companies, other than the vineries. In particular, grape pomaces are considered of interest due to their high content in bioactive molecules, especially phenolic compounds. The latter can be recovered from grape pomace and used as active ingredients in easily marketable cosmetic products. Indeed, phenolic compounds are well known for their remarkable beneficial properties at the skin level, such as antioxidant, antiaging, anti-hyperpigmentation and photoprotective effects. The exploitation of the bioactives contained in grape pomaces to obtain high value cosmetics may support the growing of innovative start-ups and expand the value chain of grapes. This review aims to describe the strategies for recovery of polyphenols from grape pomace, to highlight the beneficial potential of these extracts, both in vitro and in vivo, and their potential utilization as active ingredients in cosmetic products

Value of chemotherapy post immunotherapy in stage IV non-small cell lung cancer (NSCLC)

Background: Lung cancer is the number one cause of mortality among all types of cancer worldwide. Its treatment landscape has shifted from the classic chemotherapy alone to newer regimens based on the discovery of new immunotherapy and targeted therapy drugs. However, chemotherapy is still an option for treatment of advanced non-small cell lung cancer (NSCLC) after progression on immunotherapy alone or in combination with first-line chemotherapy. Methods: This is a retrospective study based on chart review of patients diagnosed with advanced NSCLC cases who received Docetaxel as second or third line after being treated by immunotherapy and/or chemotherapy in previous lines. The data was collected from the medical records of physicians’ clinics in three different hospital centers in Lebanon over the period of 5 years from July 2015 until December 2020. February 2021 was data analysis cut off time. The main aim was to assess the role of Docetaxel post-chemoimmunotherapy for patients with diagnosed NSCLC. Results: A total of 21 patients were included in this study. The majority of our patients were males (81%). As for histologic type, most patients had non-squamous lung cancer (67%) as compared to 33% who had squamous lung cancer. Overall, our study reported a 24% response rate to Docetaxel including stable disease and partial response and a median progression free survival (PFS) of 3 months. The mean time interval elapsed from diagnosis to the initiation of Docetaxel was 11.5 months. Conclusion: New therapeutic options should be validated for the treatment of NSCLC in the second and subsequent lines of therapy considering the poor prognosis of this disease. The chemotherapy in second and third line may keep an important role in the treatment after progression on newer agents, but it needs more evidence in prospective studies including a larger number of patients. Copyright: © 2023 Assi et al

Case report of epithelioid osteoblastoma of the mandible: findings on positron emission tomography/computed tomography and review of the literature

Epithelioid osteoblastoma is a clinically aggressive subtype of osteoblastoma that favors the mandible and the maxilla. Its histologic features lie on a spectrum between conventional osteoblastoma and low-grade osteosarcoma, thus making it difficult at times to confirm the diagnosis. It is known to have a high risk of recurrence after surgical resection, but it is a benign entity and does not have the propensity to metastasize. To our knowledge, there are no published reports on findings of epithelioid osteoblastoma on positron emission tomography/computed tomography (PET/CT). We report a case of a 25-year-old male patient with a diagnosis of epithelioid osteoblastoma of the mandible. The lesion exhibited significantly increased fluorodeoxyglucose uptake on PET/CT with a maximum standardized uptake value of 5.5. PET/CT is not specific in differentiating between malignant and benign bone lesions but may be necessary to rule out distant lesions when a confirmed diagnosis of epithelioid osteoblastoma cannot be obtained through histologic examination. © 2018 Elsevier Inc