ABSTRACT
Midbrain dopamine (mDA) neurons play an essential role in cognitive and motor behaviours and are linked to different brain disorders. However, the molecular mechanisms underlying their development, and in particular the role of non-coding RNAs (ncRNAs), remain incompletely understood. Here, we establish the transcriptomic landscape and alternative splicing patterns of circular RNAs (circRNAs) at key developmental timepoints in mouse mDA neurons in vivo using fluorescence-activated cell sorting followed by short- and long-read RNA sequencing. In situ hybridisation shows expression of several circRNAs during early mDA neuron development and post-transcriptional silencing unveils roles for different circRNAs in regulating mDA neuron morphology. Finally, in utero electroporation and time-lapse imaging implicate circRmst, a circRNA with widespread morphological effects, in the migration of developing mDA neurons in vivo. Together, these data for the first time suggest a functional role for circRNAs in developing mDA neurons and characterise poorly defined aspects of mDA neuron development.
Subject(s)
Cell Movement , Dopaminergic Neurons , Gene Expression Regulation, Developmental , Mesencephalon , RNA, Circular , Animals , RNA, Circular/genetics , RNA, Circular/metabolism , Dopaminergic Neurons/metabolism , Dopaminergic Neurons/cytology , Mesencephalon/metabolism , Mesencephalon/cytology , Mesencephalon/embryology , Mice , Cell Movement/genetics , Neurogenesis/genetics , Female , Alternative Splicing , Mice, Inbred C57BL , TranscriptomeABSTRACT
This study extensively analyzed campylobacteriosis surveillance in Portugal from 2009 to 2021, aiming to investigate demographic shifts, seasonal variations, and antimicrobial resistance (AMR) within Campylobacter isolates. Surveillance network and sentinel laboratory-based system data revealed a substantial under-notification of campylobacteriosis cases, suggesting an underestimated disease burden. Notification rates exhibited a paradigm shift, with a notable prevalence among the pediatric population, particularly in children aged 1-4 years, diverging from European reports. Additionally, an emerging trend of Campylobacter infections in younger adults (15-44 years) was observed. The study unveiled a unique seasonal distribution of cases, defying typical summer peaks seen elsewhere. AMR analysis revealed high resistance to ciprofloxacin and tetracycline, in both C. jejuni (93.7% and 79.2%, respectively) and C. coli (96.5% and 93.2%, respectively), stable throughout the studied period (2013-2021). C. coli exhibited significantly higher resistance to erythromycin, gentamicin, ampicillin and ertapenem compared to C. jejuni (p < 0.001). Multilocus Sequence Typing (MLST) data demonstrated the distribution of resistance markers across diverse sequence types, challenging the notion of a clonal origin for multidrug-resistant isolates. In conclusion, the study highlights the need for enhanced surveillance and raises concerns about alarming AMR levels, recommending the implementation of whole-genome sequencing (WGS)-based surveillance for a deeper comprehension of disease patterns and an evolving AMR landscape.
ABSTRACT
For decades, cells of the Gram-positive bacterial pathogen Staphylococcus aureus were thought to lack a dedicated elongation machinery. However, S. aureus cells were recently shown to elongate before division, in a process that requires a shape elongation division and sporulation (SEDS)/penicillin-binding protein (PBP) pair for peptidoglycan synthesis, consisting of the glycosyltransferase RodA and the transpeptidase PBP3. In ovococci and rod-shaped bacteria, the elongation machinery, or elongasome, is composed of various proteins besides a dedicated SEDS/PBP pair. To identify proteins required for S. aureus elongation, we screened the Nebraska Transposon Mutant Library, which contains transposon mutants in virtually all non-essential staphylococcal genes, for mutants with modified cell shape. We confirmed the roles of RodA/PBP3 in S. aureus elongation and identified GpsB, SsaA, and RodZ as additional proteins involved in this process. The gpsB mutant showed the strongest phenotype, mediated by the partial delocalization from the division septum of PBP2 and PBP4, two penicillin-binding proteins that synthesize and cross-link peptidoglycan. Increased levels of these PBPs at the cell periphery versus the septum result in higher levels of peptidoglycan insertion/crosslinking throughout the entire cell, possibly overriding the RodA/PBP3-mediated peptidoglycan synthesis at the outer edge of the septum and/or increasing stiffness of the peripheral wall, impairing elongation. Consequently, in the absence of GpsB, S. aureus cells become more spherical. We propose that GpsB has a role in the spatio-temporal regulation of PBP2 and PBP4 at the septum versus cell periphery, contributing to the maintenance of the correct cell morphology in S. aureus. IMPORTANCE: Staphylococcus aureus is a Gram-positive clinical pathogen, which is currently the second cause of death by antibiotic-resistant infections worldwide. For decades, S. aureus cells were thought to be spherical and lack the ability to undergo elongation. However, super-resolution microscopy techniques allowed us to observe the minor morphological changes that occur during the cell cycle of this pathogen, including cell elongation. S. aureus elongation is not required for normal growth in laboratory conditions. However, it seems to be essential in the context of some infections, such as osteomyelitis, during which S. aureus cells apparently elongate to invade small channels in the bones. In this work, we uncovered new determinants required for S. aureus cell elongation. In particular, we show that GpsB has an important role in the spatio-temporal regulation of PBP2 and PBP4, two proteins involved in peptidoglycan synthesis, contributing to the maintenance of the correct cell morphology in S. aureus.
Subject(s)
Staphylococcal Infections , Staphylococcus aureus , Humans , Staphylococcus aureus/genetics , Bacterial Proteins/metabolism , Peptidoglycan/metabolism , Penicillin-Binding Proteins/metabolism , Staphylococcal Infections/microbiology , Morphogenesis , Cell Wall/metabolismABSTRACT
Resumo O estigma da obesidade, também popularmente chamado de gordofobia, é uma realidade atual e sua superação é um desafio complexo. As concepções negativas acerca do excesso de peso também se encontram presentes entre profissionais de saúde, prejudicando a assistência prestada e trazendo danos ainda maiores na saúde de pacientes com obesidade. O objetivo do artigo é apresentar o processo de desenvolvimento de uma intervenção para redução do estigma da obesidade voltada para profissionais de saúde, que utilizou como referencial teórico o protocolo Mapeamento de Intervenções. Descreveu-se como foi realizada a avaliação de necessidades e detalharam-se as etapas referentes ao desenho e à produção da intervenção, tendo como produto final um protocolo de intervenção para redução do estigma da obesidade em profissionais de saúde pronto para ser implementado. O protocolo tem carga horária total de 20h, organizado em dez módulos, cada um com a descrição do formato e duração, objetivo, conteúdo, estratégias pedagógicas, materiais, referências e resultados esperados. O produto final representa uma contribuição para a área de saúde, que tem a intervenção elaborada minuciosamente sobre um arcabouço teórico, passível de ser aplicada e reaplicada em diferentes contextos.
Abstract The stigma of obesity, also popularly called fatphobia, is a current reality and overcoming it is a complex challenge. Negative conceptions about being overweight are also present among health professionals, compromising the care provided and causing even greater damage to the health of obese patients. The article aims to present the process of developing an intervention to reduce the stigma of obesity aimed at health professionals, which used the Intervention Mapping protocol as a theoretical framework. It was described how the needs assessment was carried out and the steps relating to the design and production of the intervention were detailed, with the final product being an intervention protocol to reduce the stigma of obesity in healthcare professionals ready to be implemented. The protocol has a total workload of 20 hours, organized into ten modules, each with a description of the format and duration, objective, content, pedagogical strategies, materials, references and expected results. The final product represents a contribution to the health area, with the intervention being meticulously elaborated on a theoretical framework, capable of being applied and reapplied in different contexts.
ABSTRACT
Patients with lower limb fractures require rehabilitation but often struggle with adherence to interventions. Adding motivational strategies to rehabilitation programs can increase patient adherence and enhance outcomes. This review aims to identify the motivational strategies used by health professionals in the rehabilitation of people with lower limb fractures. We used Arksey and O'Malley's methodological framework to structure and conduct this scoping review. The literature search was performed using the Scopus, CINAHL, MEDLINE, Nursing & Allied Health, and Cochrane Central Register of Controlled Trials databases. The final search was conducted in February 2023. A total of 1339 articles were identified. After selecting and analyzing the articles, twelve studies were included in this review. Health professionals use several strategies to motivate patients with lower limb fractures to adhere to rehabilitation programs. These strategies include building a therapeutic alliance, increasing patients' health literacy, setting achievable goals, personalizing the rehabilitation program, managing unpleasant sensations of exercise, using persuasion, providing positive reinforcement, avoiding negative emotional stimulation, and helping to seek support. The motivational strategies identified may help professionals to increase patient adherence to rehabilitation for lower limb fractures. This knowledge will allow these professionals to help patients overcome barriers to rehabilitation, enhance their motivation, and ultimately improve their recovery outcomes.
Subject(s)
Fractures, Bone , Motivation , Humans , Patient Compliance , Exercise , Lower ExtremityABSTRACT
Assessment of cold stability is essential for manufacture and commercialization of biotherapeutics. Storage stability is often estimated by measuring accelerated rates at elevated temperature and using mathematical models (as the Arrhenius equation). Although, this strategy often leads to an underestimation of protein aggregation during storage. In this work, we measured the aggregation rates of two antibodies in a broad temperature range (from 60 °C to -25 °C), using an isochoric cooling method to prevent freezing of the formulations below 0 °C. Both antibodies evidenced increasing aggregation rates when approaching extreme temperatures, because of hot and cold denaturation. This behavior was modelled using Arrhenius and Gibbs-Helmholtz equations, which enabled to deconvolute the contribution of unfolding from the protein association kinetics. This approach made possible to model the aggregation rates at refrigeration temperature (5 °C) in a relatively short timeframe (1-2 weeks) and using standard characterization techniques (SEC-HPLC and DLS).
Subject(s)
Antibodies , Cold Temperature , Protein Stability , Temperature , Freezing , Protein DenaturationABSTRACT
Mesial temporal lobe epilepsy (mTLE) is a chronic disease characterized by recurrent seizures that originate in the temporal lobes of the brain. Anti-epileptic drugs (AEDs) are the standard treatment for managing seizures in mTLE patients, but are frequently ineffective. Resective surgery is an option for some patients, but does not guarantee a postoperative seizure-free period. Therefore, further insight is needed into the pathogenesis of mTLE to enable the design of new therapeutic strategies. Circular RNAs (circRNAs) have been identified as important regulators of neuronal function and have been implicated in epilepsy. However, the mechanisms through which circRNAs contribute to epileptogenesis remain unknown. Here, we determine the circRNA transcriptome of the hippocampus and cortex of mTLE patients by using RNA-seq. We report 333 differentially expressed (DE) circRNAs between healthy individuals and mTLE patients, of which 23 circRNAs displayed significant adjusted p-values following multiple testing correction. Interestingly, hippocampal expression of circ_Satb1, a circRNA derived from special AT-rich sequence binding protein 1 (SATB1), is decreased in both mTLE patients and in experimental epilepsy. Our work shows that circ_Satb1 displays dynamic patterns of neuronal expression in vitro and in vivo. Further, circ_Satb1-specific knockdown using CRISPR/CasRx approaches in hippocampal cultures leads to defects in dendritic spine morphology, a cellular hallmark of mTLE. Overall, our results identify a novel epilepsy-associated circRNA with disease-specific expression and previously unidentified cellular effects that are relevant for epileptogenesis.
ABSTRACT
Mesial temporal lobe epilepsy (mTLE) is a common form of epilepsy and is characterized by recurrent spontaneous seizures originating from the temporal lobe. The majority of mTLE patients develop pharmacoresistance to available anti-epileptic drugs (AEDs) while exhibiting severe pathological changes that can include hippocampal atrophy, neuronal death, gliosis and chronic seizures. The molecular mechanisms leading to mTLE remain incompletely understood, but are known to include defects in post-transcriptional gene expression regulation, including in non-coding RNAs (ncRNAs). Circular RNAs (circRNAs) are a class of recently rediscovered ncRNAs with high levels of expression in the brain and proposed roles in diverse neuronal processes. To explore a potential role for circRNAs in epilepsy, RNA-sequencing (RNA-seq) was performed on hippocampal tissue from a rat perforant pathway stimulation (PPS) model of TLE at different post-stimulation time points. This analysis revealed 218 differentially expressed (DE) circRNAs. Remarkably, the majority of these circRNAs were changed at the time of the occurrence of the first spontaneous seizure (DOFS). The expression pattern of two circRNAs, circ_Arhgap4 and circ_Nav3, was further validated and linked to miR-6328 and miR-10b-3p target regulation, respectively. This is the first study to examine the regulation of circRNAs during the development of epilepsy. It reveals an intriguing link between circRNA deregulation and the transition of brain networks into the state of spontaneous seizure activity. Together, our results provide a molecular framework for further understanding the role and mechanism-of-action of circRNAs in TLE.
ABSTRACT
Long non-coding RNAs (lncRNAs) are RNAs that exceed 200 nucleotides in length and that are not translated into proteins. Thousands of lncRNAs have been identified with functions in processes such as transcription and translation regulation, RNA processing, and RNA and protein sponging. LncRNAs show prominent expression in the nervous system and have been implicated in neural development, function and disease. Recent work has begun to report on the expression and roles of lncRNAs in motor neurons (MNs). The cell bodies of MNs are located in cortex, brainstem or spinal cord and their axons project into the brainstem, spinal cord or towards peripheral muscles, thereby controlling important functions such as movement, breathing and swallowing. Degeneration of MNs is a pathological hallmark of diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. LncRNAs influence several aspects of MN development and disruptions in these lncRNA-mediated effects are proposed to contribute to the pathogenic mechanisms underlying MN diseases (MNDs). Accumulating evidence suggests that lncRNAs may comprise valuable therapeutic targets for different MNDs. In this review, we discuss the role of lncRNAs (including circular RNAs [circRNAs]) in the development of MNs, discuss how lncRNAs may contribute to MNDs and provide directions for future research.
Subject(s)
Motor Neuron Disease/genetics , Motor Neurons/physiology , RNA, Long Noncoding/genetics , RNA, Long Noncoding/physiology , Animals , Humans , Motor Neuron Disease/physiopathologyABSTRACT
Introdução: A pesquisa teve como objetivo propor e avaliar um programa cognitivo-comportamental de educação nutricional para mulheres com excesso de peso e identificar fatores que interferem na adesão. Métodos: estudo qualiquantitativo, quase experimental, com mulheres com excesso de peso, alocadas em dois grupos: um que participou de um programa em grupo baseado no modelo cognitivo-comportamental e outro que recebeu acompanhamento individual. Foram comparados dados antropométricos e bioquímicos, além de fatores relacionados à adesão. Resultados: Os dados antropométricos e bioquímicos não diferiram significativamente entre os grupos. A análise qualitativa evidenciou mudanças relevantes em relação à qualidade e quantidade da alimentação ingerida. Discussão: As estratégias utilizadas permitiram a elaboração de recursos cognitivos relevantes para perda de peso. Conclusões: O programa auxiliou em mudanças nos hábitos alimentares, o que pode repercutir em alterações antropométricas e bioquímicas relevantes no médio prazo.
Introduction: The objective of this research was to propose and evaluate a cognitive behavioral nutrition education program for overweight women and to identify factors that interfere with adherence. Methods: A quasi-experimental, qualitative and quantitative study, were performed. Overweight women were separated in two groups: one who participated in a group program based on the cognitive behavioral model and the other who received individual follow-up. Anthropometric and biochemical data were compared, as well as factors related to adherence. Results: Anthropometric and biochemical data did not differ significantly between groups. The qualitative analysis showed important changes in relation to the quality and quantity of the food ingested. Discussion: The strategies used allowed the elaboration of relevant cognitive resources for weight loss. Conclusions: The program assisted in changes in eating habits, which may impact on relevant anthropometric and biochemical changes in the medium term.
Introducción: La investigación tuvo como objetivo proponer y evaluar un programa educativo de nutrición cognitiva conductual para mujeres con sobrepeso e identificar factores que interfieren con la adherencia. Métodos: Un estudio cualitativo y cuantitativo, cuasi-experimental, de mujeres con sobrepeso que fueron asignadas en dos grupos: uno que participó en un programa grupal basado en el modelo cognitivo conductual y el otro que recibió un seguimiento individual. Se compararon datos antropométricos y bioquímicos, así como factores relacionados con la adherencia. Resultados: Los datos antropométricos y bioquímicos no difirieron significativamente entre los grupos. El análisis cualitativo mostró cambios en relación con la calidad y cantidad de los alimentos ingeridos. Discusión: Las estrategias utilizadas permitieron la elaboración de recursos cognitivos relevantes para la pérdida de peso. Conclusiones: El programa ayudó a los cambios en los hábitos alimenticios, lo que puede afectar los cambios antropométricos y bioquímicos relevantes en el mediano plazo.
ABSTRACT
O número de pessoas com alterações do foro neurológico, com idade superior a 65 anos de idade tem vindo a aumentar ao longo dos anos. A intervenção do enfermeiro de reabilitação visa a capacitação da pessoa para a execução dos seus autocuidados e a demonstração dos resultados sensíveis aos cuidados de enfermagem de reabilitação, permitindo comprovar a qualidade dos cuidados prestados. Este relatório desenvolveu-se através da aplicação de uma proposta estruturada de intervenção dos cuidados de enfermagem de reabilitação, seguindo a metodologia qualitativa de Robert Yin (estudos de caso múltiplos), a teoria de médio alcance de Lopes e o modelo de Fonseca e Lopes, baseado na teoria do défice do autocuidado de Orem. A intervenção realizada mostrou os ganhos sensíveis aos cuidados da enfermagem de reabilitação. Este relatório permitiu a demonstração da aquisição de competências na área de especialidade de enfermagem de reabilitação e de mestre em enfermagem.
The number of people with neurological changes, over the age of 65 has been increasing over the years. The intervention of the rehabilitation nurse aims at training the person to perform their self-care and a demonstration of the results obtained in the rehabilitation nursing care, allowing to prove the quality of the care provided. This report is revealed through the application of a structured intervention proposal for rehabilitation nursing care, following the qualitative methodology of Robert Yin (multiple case studies), the medium-range theory Lopes and the model de Fonseca and Lopes, based on Orem's self-care deficit theory. The intervention shown in the gains associated with nursing. This report complements the demonstration of the acquisition of skills in the area of specialty of rehabilitation nursing and master in nursing.
Subject(s)
Self Care , Rehabilitation Nursing , Nervous System Diseases , Aged , Patient Education as TopicABSTRACT
Bottles and carboys are used for frozen storage and transport of biopharmaceutical formulations under a wide range of conditions. The quality of freezing and thawing in these systems has been questioned due to the formation of heterogeneous ice structures and deformation of containers. This work shows that during freezing of bulk protein solutions, the liquid at the air-liquid interface freezes first, forming an ice crust and enclosing the liquid phase. As the enclosed liquid freezes, internal pressure rises, pushing the liquid phase through the porous ice crust towards the air interface, leading to interfacial stress and protein aggregation. The aggregation of bovine serum albumin was more intense in the foam-like ice mound that was formed at the top, where bubbles were entrapped. This was characterized experimentally with the assistance of magnetic resonance imaging (MRI). An isothermal cover is proposed to prevent the early freezing of the liquid at the air interface, attenuating substantially interfacial stress to proteins and releasing hydrostatic pressure, preserving the shape and integrity of the containers.
Subject(s)
Freezing , Heating , Serum Albumin, Bovine/chemistry , Stress, Mechanical , Porosity , Pressure , SolutionsABSTRACT
Optimization of protein formulations at subzero temperatures is required for many applications such as storage, transport, and lyophilization. Using isochoric cooling (constant volume) is possible to reach subzero temperatures without freezing aqueous solutions. This accelerates protein damage as protein may unfold by cold denaturation and diffusional and conformational freedom is still present. The use of isochoric cooling to faster protein formulations was first demonstrated for the biomedical relevant protein disulfide isomerase A1. Three osmolytes, sucrose, glycerol, and l-arginine, significantly increased the stability of protein disulfide isomerase A1 at -20°C with all tested under isochoric cooling within the short time frame of 700 h. The redox green fluorescent protein 2 was used to evaluate the applicability of isochoric cooling for stability analysis of highly stable proteins. This derivative of GFP is 2.6-fold more stable than the highly stable GFP ß-barrel structure. Nevertheless, it was possible to denature a fraction of roGFP2 at -20°C and to assign a stabilizing effect to sucrose. Isochoric cooling was further applied to insulin. Protein damage was evaluated through a signaling event elicited on human hepatocyte carcinoma cells. Insulin at -20°C under isochoric cooling lost 22% of its function after 15 days and 0.6M sucrose prevented insulin deactivation.
Subject(s)
Green Fluorescent Proteins/chemistry , Recombinant Proteins/chemistry , Cold Temperature , Drug Compounding , Drug Stability , Freezing , Hemoglobins/chemistry , Hep G2 Cells , Humans , Insulin/chemistry , Insulin/pharmacology , Phase Transition , Procollagen-Proline Dioxygenase/chemistry , Protein Denaturation , Protein Disulfide-Isomerases/chemistry , Protein Refolding , Protein Stability , ThermodynamicsABSTRACT
The adsorption of intact liposomes on surfaces is of great importance for the development of sensors and drug delivery systems and, also, strongly dependent on the surface roughness where the liposomes are adsorbed. In this paper, we analyzed, by using atomic force microscopy in liquid, the evolution of the morphology of gold surfaces and of poly(allylamine hydrochloride) (PAH) surfaces with different roughness during the adsorption of liposomes prepared with the synthetic phospholipid 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)]. Our results reveal the following. On smooth surfaces of Au only and Au with PAH, the liposomes open and deploy on the substrate, creating a supported-lipid bilayer, with the opening process being faster on the Au/PAH surface. On rough substrates of Au coated with polyelectrolyte multilayers, the liposomes were adsorbed intact on the surface. This was corroborated by power spectral density analysis that demonstrates the presence of superstructures with an average lateral size of 43 and 87 nm, in accordance with two and four times the mean liposome hydrodynamic diameter of about 21 nm. In addition, this work presents an adequate and effective methodology for analysis of adsorption phenomena of liposomes on rough surfaces.
Subject(s)
Gold/chemistry , Liposomes/chemistry , Microscopy, Atomic Force/methods , Phosphatidylglycerols/chemistry , Adsorption , Drug Delivery Systems , Fractals , Kinetics , Lipid Bilayers , Models, Structural , Molecular Structure , Polyamines/chemistry , Surface PropertiesABSTRACT
Cystic fibrosis (CF), the most common inherited disease in Caucasians, is caused by mutations in the CFTR chloride channel, the most frequent of which is Phe508del. Phe508del causes not only intracellular retention and premature degradation of the mutant CFTR protein, but also defective channel gating and decreased half-life when experimentally rescued to the plasma membrane (PM). Despite recent successes in the functional rescue of several CFTR mutations with small-molecule drugs, the folding-corrector/gating-potentiator drug combinations approved for Phe508del-CFTR homozygous patients have shown only modest benefit. Several factors have been shown to contribute to this outcome, including an unexpected intensification of corrector-rescued Phe508del-CFTR PM instability after persistent co-treatment with potentiator drugs. We have previously shown that acute co-treatment with hepatocyte growth factor (HGF) can significantly enhance the chemical correction of Phe508del-CFTR. HGF coaxes the anchoring of rescued channels to the actin cytoskeleton via induction of RAC1 GTPase signalling. Here, we demonstrate that a prolonged, 15-day HGF treatment also significantly improves the functional rescue of Phe508del-CFTR by the VX-809 corrector/VX-770 potentiator combination, in polarized bronchial epithelial monolayers. Importantly, we found that HGF treatment also prevented VX-770-mediated destabilization of rescued Phe508del-CFTR and enabled further potentiation of the rescued channels. Most strikingly, prolonged HGF treatment prevented previously unrecognized epithelial dedifferentiation effects of sustained exposure to VX-809. This was observed in epithelium-like monolayers from both lung and intestinal origin, representing the two systems most affected by adverse symptoms in patients treated with VX-809 or the VX-809/VX-770 combination. Taken together, our findings strongly suggest that co-administration of HGF with corrector/potentiator drugs could be beneficial for CF patients.
Subject(s)
Aminophenols/administration & dosage , Aminopyridines/administration & dosage , Benzodioxoles/administration & dosage , Chloride Channel Agonists/administration & dosage , Cystic Fibrosis Transmembrane Conductance Regulator/deficiency , Cystic Fibrosis/drug therapy , Hepatocyte Growth Factor/administration & dosage , Quinolones/administration & dosage , Cell Line , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Humans , Models, Biological , Mutant Proteins/genetics , Treatment OutcomeABSTRACT
Low drug bioavailability, which is mostly a result of poor aqueous drug solubilities and of inadequate drug dissolution rates, is one of the most significant challenges that pharmaceutical companies are currently facing, since this may limit the therapeutic efficacy of marketed drugs, or even result in the discard of potential highly effective drug candidates during developmental stages. Two of the main approaches that have been implemented in recent years to overcome poor drug solubility/dissolution issues have frequently involved drug particle size reduction (i.e., micronization/nanonization) and/or the modification of some of the physicochemical and structural properties of poorly water soluble drugs. A large number of particle engineering methodologies have been developed, tested, and applied in the synthesis and control of particle size/particle-size distributions, crystallinities, and polymorphic purities of drug micro- and nano-particles/crystals. In recent years pharmaceutical processing using supercritical fluids (SCF), in general, and supercritical carbon dioxide (scCO2), in particular, have attracted a great attention from the pharmaceutical industry. This is mostly due to the several well-known advantageous technical features of these processes, as well as to other increasingly important subjects for the pharmaceutical industry, namely their "green", sustainable, safe and "environmentally-friendly" intrinsic characteristics. In this work, it is presented a comprehensive state-of-the-art review on scCO2-based processes focused on the formation and on the control of the physicochemical, structural and morphological properties of amorphous/crystalline pure drug nanoparticles. It is presented and discussed the most relevant scCO2, scCO2-based fluids and drug physicochemical properties that are pertinent for the development of successful pharmaceutical products, namely those that are critical in the selection of an adequate scCO2-based method to produce pure drug nanoparticles/nanocrystals. scCO2-based nanoparticle formation methodologies are classified in three main families, and in terms of the most important role played by scCO2 in particle formation processes: as a solvent; as an antisolvent or a co-antisolvent; and as a "high mobility" additive (a solute, a co-solute, or a co-solvent). Specific particle formation methods belonging to each one of these families are presented, discussed and compared. Some selected amorphous/crystalline drug nanoparticles that were prepared by these methods are compiled and presented, namely those studied in the last 10-15â¯years. A special emphasis is given to the formation of drug cocrystals. It is also discussed the fundamental knowledge and the main mechanisms in which the scCO2-based particle formation methods rely on, as well as the current status and urgent needs in terms of reliable experimental data and of robust modeling approaches. Other addressed and discussed topics include the currently available and the most adequate physicochemical, morphological and biological characterization methods required for pure drug nanoparticles/nanocrystals, some of the current nanometrology and regulatory issues associated to the use of these methods, as well as some scale-up, post-processing and pharmaceutical regulatory subjects related to the industrial implementation of these scCO2-based processes. Finally, it is also discussed the current status of these techniques, as well as their future major perspectives and opportunities for industrial implementation in the upcoming years.
Subject(s)
Carbon Dioxide/chemistry , Chromatography, Supercritical Fluid , Nanoparticles/chemistry , Pharmaceutical Preparations/chemical synthesis , Humans , Pharmaceutical Preparations/chemistryABSTRACT
BACKGROUND: In this paper, various extra-virgin and virgin olive oils samples from different Portuguese markets were studied. For this purpose, a voltammetric electronic tongue (VE-tongue), consisting of two kinds of working electrode within the array, together with physicochemical analysis and headspace gas chromatography coupled with mass spectrometry (HS-GC-MS), were applied. In addition, preliminary considerations of relationships between physicochemical parameters and multisensory system were reported. RESULTS: The physicochemical parameters exhibit significant differences among the analyzed olive oil samples that define its qualities. Regarding the aroma profile, 14 volatile compounds were characterized using HS-GC-MS; among these, hex-2-enal, hexanal, acetic acid, hex-3-ene-1-ol acetate and hex-3-en-1-ol were semi-quantitatively detected as the main aroma compounds in the analyzed samples. Moreover, pattern recognition methods demonstrate the discrimination power of the proposed VE-tongue system. The results reveal the VE-tongue's ability to classify olive oil samples and to identify unknown samples based of built models. In addition, the correlation between VE-tongue and physicochemical analysis exhibits a remarkable prediction model aimed at anticipating carotenoid content. CONCLUSION: The preliminary results of this investigation indicate that physicochemical and HS-GC-MS analysis, together with multisensory system coupled with chemometric techniques, presented a satisfactory performance regarding olive oil sample discrimination and identification. © 2017 Society of Chemical Industry.
Subject(s)
Electrochemical Techniques/instrumentation , Food Analysis/methods , Gas Chromatography-Mass Spectrometry/methods , Olive Oil/chemistry , Volatile Organic Compounds/chemistry , Carotenoids , Chlorophyll , Fatty Acids, Nonesterified , Odorants , Portugal , Solid Phase MicroextractionABSTRACT
The eukaryotic initiation factor 3 (eIF3) is one of the most complex translation initiation factors in mammalian cells, consisting of several subunits (eIF3a to eIF3m). It is crucial in translation initiation and termination, and in ribosomal recycling. Accordingly, deregulated eIF3 expression is associated with different pathological conditions, including cancer. In this manuscript, we discuss the interactome and function of each subunit of the human eIF3 complex. Furthermore, we review how altered levels of eIF3 subunits correlate with neurodegenerative disorders and cancer onset and development; in addition, we evaluate how such misregulation may also trigger infection cascades. A deep understanding of the molecular mechanisms underlying eIF3 role in human disease is essential to develop new eIF3-targeted therapeutic approaches and thus, overcome such conditions.
Subject(s)
Eukaryotic Initiation Factor-3/genetics , Gene Expression Regulation/genetics , Molecular Targeted Therapy , Protein Biosynthesis , Humans , Neoplasms/genetics , Neoplasms/therapy , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/therapyABSTRACT
The aim of this work was focused on the development of carboxymethyl xylan (CMX) formulations with functional properties to produce edible films. Beechwood Xylan was firstly derivatized into carboxymethyl xylan and thereafter was blended with Agar (Ag), Ammonium zirconium carbonate (AZC) and linoleic acid (La) to produce CMX:Ag, CMX:AZC, CMX:Ag:La films. Mechanical, barrier, optical and thermal properties of the produced films and their antimicrobial activity against food pathogenic bacteria were evaluated. The obtained films were transparent and yellowish. Agar and AZC improved the tensile strength at break of the control CMX film from 4.79 to 27.67 and 20.95 MPa respectively, and the CMX:AZC film exhibited the greatest elastic modulus. Barrier properties of the films decreased when any of the components was incorporated into the CMX and all blended films were thermally more stable than control. The CMX:Ag:La film revealed a good antimicrobial activity against B. cereus and S. aureus.
ABSTRACT
Acinetobacter baumannii is an emerging pathogen associated with nosocomial infections that in addition has shown an increasing resistance to antibiotics. In this work the genetic diversity of A. baumannii isolates from a Portuguese hospital, their antibiotic resistance profiles and ability to form biofilms was studied. Seventy-nine clinical A. baumannii isolates were characterized by pulsed-field gel electrophoresis (PFGE) with 9 different PFGE profiles being obtained. Concerning the antimicrobial susceptibility, all A. baumannii isolates were resistant to 12 of the 17 tested antibiotics and classified as multidrug-resistant (MDR). In addition, 74.7% of the isolates showed biofilm formation ability, however no statistical significance with antibiotic resistance was observed. In contrast, urine samples isolates were more likely to form biofilms than strains isolated from other sources. Our findings highlight the high number of MDR A. baumannii isolates and the importance of the formation of biofilms as a potential virulence factor.