24 research outputs found
Convolutional Neural Network for Segmentation and Classification of Glaucoma
Glaucoma is an eye disease that is caused by elevated intraocular pressure and commonly leads to optic nerve damage. Thanks to its vital role in transmitting visual signals from the eye to the brain, the optic nerve is essential for maintaining good and clear vision. Glaucoma is considered one of the leading causes of blindness. Accordingly, the earlier doctors can diagnose and detect the disease, the more feasible its treatment becomes. Aiming to facilitate this task, this study proposes a method for detecting diseases by analyzing images of the interior of the eye using a convolutional neural network. This method consists of segmentation based on a modified U-Net architecture and classification using the DenseNet-201 technique. The proposed model utilized the DRISHTI-GS and RIM-ONE datasets to evaluate glaucoma images. These datasets served as valuable sources of diverse and representative glaucoma-related images, enabling a thorough evaluation of the model’s performance. Finally, the results were highly promising after subjecting the model to a thorough evaluation process. The segmentation accuracy reached 96.65%, while the classification accuracy reached 96.90%. This means that the model excelled in accurately delineating and isolating the relevant regions of interest within the eye images, such as the optical disc and optical cup, which are crucial for diagnosing glaucoma
Targeting Splicing in the Treatment of Human Disease
The tightly regulated process of precursor messenger RNA (pre-mRNA) alternative splicing (AS) is a key mechanism in the regulation of gene expression. Defects in this regulatory process affect cellular functions and are the cause of many human diseases. Recent advances in our understanding of splicing regulation have led to the development of new tools for manipulating splicing for therapeutic purposes. Several tools, including antisense oligonucleotides and trans-splicing, have been developed to target and alter splicing to correct misregulated gene expression or to modulate transcript isoform levels. At present, deregulated AS is recognized as an important area for therapeutic intervention. Here, we summarize the major hallmarks of the splicing process, the clinical implications that arise from alterations in this process, and the current tools that can be used to deliver, target, and correct deficiencies of this key pre-mRNA processing event. Keywords: alternative splicing, precursor messenger RNA, therapy, genetic diseas
Cholesteryl oleate-loaded cationic solid lipid nanoparticles as carriers for efficient gene-silencing therapy
Background: Cationic solid lipid nanoparticles (SLNs) have been given considerable attention for therapeutic nucleic acid delivery owing to their advantages over viral and other nanoparticle delivery systems. However, poor delivery efficiency and complex formulations hinder the clinical translation of SLNs. Aim: The aim of this study was to formulate and characterize SLNs incorporating the cholesterol derivative cholesteryl oleate to produce SLN-nucleic acid complexes with reduced cytotoxicity and more efficient cellular uptake. Methods: Five cholesteryl oleate-containing formulations were prepared. Laser diffraction and laser Doppler microelectrophoresis were used to evaluate particle size and zeta potential, respectively. Nanoparticle morphology was analyzed using electron microscopy. Cytotoxicity and cellular uptake of lipoplexes were evaluated using flow cytometry and fluorescence microscopy. The gene inhibition capacity of the lipoplexes was assessed using siRNAs to block constitutive luciferase expression. Results: We obtained nanoparticles with a mean diameter of approximately 150-200 nm in size and zeta potential values of 25-40 mV. SLN formulations with intermediate concentrations of cholesteryl oleate exhibited good stability and spherical structures with no aggregation. No cell toxicity of any reference SLN was observed. Finally, cellular uptake experiments with DNAand RNA-SLNs were performed to select one reference with superior transient transfection efficiency that significantly decreased gene activity upon siRNA complexation. Conclusion: The results indicate that cholesteryl oleate-loaded SLNs are a safe and effective platform for nonviral nucleic acid delivery
Improved synthesis and characterization of cholesteryl oleate-loaded cationic solid lipid nanoparticles with high transfection efficiency for gene therapy applications
The development of new nanoparticle formulations that are capable of high transfection efficiency without toxicity is essential to provide new tools for gene therapy. However, the issues of complex, poorly reproducible manufacturing methods, and low efficiencies during in vivo testing have prevented translation to the clinic. We have previously reported the use of cholesteryl oleate as a novel excipient for solid lipid nanoparticles (SLNs) for the development of highly efficient and nontoxic nucleic acid delivery carriers. Here, we performed an extensive characterization of this novel formulation to make the scale up under Good Manufacturing Practice (GMP) possible. We also describe the complete physicochemical and biological characterization of cholesteryl oleate-loaded SLNs to ensure the reproducibility of this formula and the preservation of its characteristics before and after the lyophilization process. We defined the best manufacturing method and studied the influence of some parameters on the obtained nanoparticles using the Quality by Design (ICH Q8) guideline to obtain cholesteryl oleate-loaded SLNs that remain stable during storage and guarantee in vitro nucleic acid delivery efficacy. Our results indicate that this improved formulation is suitable for gene therapy with the possibility of scale-up the manufacturing of nanoparticles under GMP conditions
Interfacial rheology testing of molten polymer systems: Effect of molecular weight and temperature on the interfacial properties
International audienc
Probing the elongational rheological behaviour at interfaces of immiscible polymer melts using dilational tensiometry: effect of viscosity and temperature on the interfacial properties
International audienc
Recent Advances in the Interfacial Shear and Dilational Rheology of Polymer Systems: From Fundamentals to Applications
The study of the viscoelastic properties of polymer systems containing huge internal two-dimensional interfacial areas, such as blends, foams and multilayer films, is of growing interest and plays a significant role in a variety of industrial fields. Hence, interfacial rheology can represent a powerful tool to directly investigate these complex polymer–polymer interfaces. First, the current review summarizes the theoretical basics and fundamentals of interfacial shear rheology. Particular attention has been devoted to the double-wall ring (DWR), bicone, Du Noüy ring and oscillating needle (ISR) systems. The measurement of surface and interfacial rheological properties requires a consideration of the relative contributions of the surface stress arising from the bulk sub-phases. Here, the experimental procedures and methodologies used to correct the numerical data are described considering the viscoelastic nature of the interface. Second, the interfacial dilational rheology is discussed, starting with the theory and underlying principles. In particular, the Langmuir trough method, the oscillating spinning drop technique and the oscillating pendant drop technique are investigated. The major pioneering studies and latest innovations dedicated to interfacial rheology in both shear and dilatation–compression are highlighted. Finally, the major challenges and limits related to the development of high-temperature interfacial rheology at the molten state are presented. The latter shows great potential for assessing the interfaces of polymer systems encountered in many high-value applications
Vigilance towards the use of artificial intelligence applications for breast cancer screening and early diagnosis
Breast cancer is a real public health problem in Morocco. It is the cause of a significant number of deaths caused by late diagnosis. Mammography plays an essential role in the detection of breast cancer and in the early management of its treatment. Despite the existence of screening programs, there are still high rates of false positives and false negatives. Indeed, women were called back for additional diagnoses based on suspicious results that eventually led to cancer. Artificial intelligence (AI) algorithms represent a promising solution to improve the accuracy of digital mammography offering, on the one hand, the possibility of better cancer detection, and, on the other hand, improved efficiency for radiologists for good decision-making.
In this work, through a review of the literature on the tools used to evaluate the performance of AI systems dedicated to early detection and diagnosis of breast cancer. We set out to answer the following questions: Is the ethics relating to patient data during the development phase of this software is respected? Do these tools take into consideration the specificities of the field? What about the specification, accuracy and limitations of these applications?
At the end, we show through this work recommendations to adapt these evaluation tools of AI applications for breast cancer screening for an optimized and rational consideration of the principle of health vigilance and compliance with the regulatory standards in force governing this field
Targeting Splicing in the Treatment of Human Disease
The tightly regulated process of precursor messenger RNA (pre-mRNA) alternative splicing (AS) is a key mechanism in the regulation of gene expression. Defects in this regulatory process affect cellular functions and are the cause of many human diseases. Recent advances in our understanding of splicing regulation have led to the development of new tools for manipulating splicing for therapeutic purposes. Several tools, including antisense oligonucleotides and trans-splicing, have been developed to target and alter splicing to correct misregulated gene expression or to modulate transcript isoform levels. At present, deregulated AS is recognized as an important area for therapeutic intervention. Here, we summarize the major hallmarks of the splicing process, the clinical implications that arise from alterations in this process, and the current tools that can be used to deliver, target, and correct deficiencies of this key pre-mRNA processing event.This work was supported by grants from the Spanish Ministry of Economy and
Competitiveness (grant number BFU2014-54660-R) and the Andalusian Government (Excellence Project
BIO-2515/2012) to Carlos Suñé and from the Spanish Ministry of Economy and Competitiveness (grant number
BFU2016-79699-P) and the Andalusian Government (Excellence Project CTS-6587) to Cristina Hernández-Munain
Support from the European Region Development Fund (ERDF (FEDER)) is also acknowledged. We apologize to
all researchers whose papers pertinent to this article we failed to citeWe acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)
Drosophila pre-mRNA processing factor Prp40 localizes to Histone Locus Body and regulates histone mRNA transcription
In eukaryotic cells, the nucleus is compartmentalized and contains several dynamic nonmembrane-
bound structures referred to as nuclear bodies, which are essential for correct
maintenance of nuclear architecture and the gene-regulatory processes that occur within the
nucleus. Several nuclear bodies are associated with specific gene loci and this association with a
specific nuclear function or activity may be important for their formation and activity. The
Histone Locus Body (HLB) is an example of a chromatin-associated nuclear body. The HLB
associates specifically with the replication-dependent histone gene clusters to coordinate the
transcription and 3Âż-end processing of histone pre-mRNA. In mammalian cells, a large amount
of histones must be synthesized during S phase of the cell cycle to package the newly
synthesized DNA into chromatin. Defects in the synthesis of histones result in genome
instability that can lead to disease.
Herein, we identified the pre-mRNA processing factor 40 (Prp40) ortholog in Drosophila and
identified a role for this protein in histone mRNA expression. We show that Prp40 localizes to
the Drosophila HLB after the incorporation of their primary founders and concomitant to the
activation of histone gene transcription during prophase. We demonstrate that Prp40 is essential
for Drosophila development. Moreover, Drosophila Prp40 and their human orthologs can
rescue the Prp40-mutant flies, demonstrating a functional conservation of eukaryotic Prp40
activities in vivo. Placing our data in a molecular context, we show that depletion of Prp40 from
fly cells inhibited histone mRNA transcription in vivo. The H3-H4-dependent transcription,
which is essential for HLB assembly and high-level histone gene expression, was rescued by
overexpressing Prp40 in the depleted cells. We also show that Prp40 is required for
transcription initiation and not for the elongation or 3Âż end maturation of histone mRNAs.
Together, our results identify a novel HLB-associated protein and provide evidence for a
relevant role of Prp40 in regulating histone mRN