Browsing by Author "Marques-Ramos, Ana"
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- Cytotoxicity assessment of nanoplastics and plasticizers exposure in in vitro lung cell culture systems: a systematic reviewPublication . Clérigo, Fabiana; Ferreira, Sandra; Ladeira, Carina; Marques-Ramos, Ana; Almeida-Silva, M.; Mendes, L. A.Emerging contaminants such as nanoplastics (NPs), as well as manufacturing by-products such as plasticizers, have gained global attention and concern due to their limited biodegradability and their potential impact on human health, in particular the effects on respiratory tissue. In parallel, in vitro cell culture techniques are key to the assessment and characterization of toxic effects and cellular mechanisms in different types of tissues and should provide relevant information to understand the hazardous potential of these emergent contaminants. This systematic review presents the main results of the current knowledge of the effects of NPs and plasticizers on lung cells, as assessed with the use of in vitro cell culture techniques. From the selected studies (n = 10), following the PRISMA approach, it was observed that cell viability was the most frequently assessed endpoint and that most studies focused on epithelial cells and exposures to polystyrene (PS). It was observed that exposure to NPs or plasticizers induces cytotoxicity in a dose-dependent manner, regardless of the size of the NPs. Furthermore, there is evidence that the characteristics of NPs can affect the toxic response by promoting the association with other organic compounds. As such, further in vitro studies focusing on the combination of NPs with plasticizers will be essential for the understanding of the mechanisms of NPs toxicity.
- Detection of Helicobacter pylori in extragastric tissues: association of infection with carcinogenesisPublication . Faria, L. M.; Almeida, M. S.; Amaral, M. R.; Marques-Ramos, AnaIntroduction: Helicobacter pylori (HP) is a gram-negative microaerophilic bacterium that has been described as the main pathogen of several benign and malignant diseases of the digestive tract, such as gastric and duodenal ulcers, chronic gastritis, hepatobiliary diseases, gastric lymphoma, and carcinoma. HP was classified as class I human carcinogen in 1994. The relationship between HP infection and extragastric diseases has been investigated over the years with contradictory conclusions. The objective of this work is to perform a bibliographic review on the association between HP infection and the development of extragastric pathologies, particularly of pancreatic carcinoma. It is also intended to determine the best method for the detection of the bacterium. Materials and methods: work was based on the literature from the following databases: b-on, PubMed, SciELO, Wiley Online Library and Scientific Repository of the Polytechnic Institute of Lisbon, under the terms “Helicobacter spp.”, “Helicobacter pylori”, “pancreatic cancer”, “extragastric diseases”, “risk of pancreatic cancer” and “CagA”. From a total of 32 analyzed articles, 18 were selected, excluding those with dubious methods and results that were not performed in human samples and meta-analysis. Results: In the selected studies the presence of HP DNA was detected by Polymerase Chain Reaction (PCR) in more than 50% of the pancreatic and hepatocellular cancer samples. There was also an association between the presence of this bacterium and colonic cancer, primary sclerosing cholangitis, primary biliary cirrhosis, cholecystitis and biliary tract carcinoma. However, detection by enzyme-linked immunosorbent assay provided ambiguous results, with 2 of the studies showing no association between infection and pancreatic cancer, while others showed positive results below 50%. There are also 3 studies that related the seroconversion of cytotoxin-associated gene A negative to pancreatic carcinoma. Other methods like histochemical and immunocytochemistry (ICQ) techniques were compared to each other and the results demonstrated that ICQ had the greatest consistency. Conclusions: The majority of the studies demonstrated an association between HP infection and the development of extragastric diseases. Therefore, HP is a potential risk factor for the etiology of these pathologies. Comparing previous methods, it was possible to observe that PCR was the most sensitive and specific technique for HP detection.
- Determinação da eficiência de obtenção de DNA a partir de secções histológicas submetidas a técnicas histoquímicasPublication . Pote, Alexandra; Freitas, Beatriz; Boghenco, Otília; Marques-Ramos, AnaIntrodução: Devido à deteção precoce de lesões, as amostras para análise molecular são cada vez mais reduzidas e a quantidade DNA pode não ser suficiente para obter resultados, tornando-se necessário extrair DNA diretamente de tecidos corados. Apesar da influência das colorações na obtenção de DNA já ter sido estudada, esta é uma área pouco explorada. Objetivo do estudo: Apresentar a recolha de dados referentes à influência de técnicas histoquímicas na integridade do DNA.
- Development of an indexed score to identify the most suitable biological material to assess SARS-CoV-2Publication . Almeida-Silva, Marina; Cervantes, Renata; Ribeiro, Edna; Marques-Ramos, AnaIntroduction: The rapidly contagious process of respiratory viruses such as SARS-CoV-2 makes it urgent to multiply testing for diagnostics to identify the active viral shedding cases (current infection, carriage state, or, residual viral RNA) and decrease the risk of transmission to other patients and healthcare professionals. Although nasopharyngeal swabs (NPSs) are the most common specimen type used for COVID-19 diagnosis, they require supervision by a professional, and concerns have been raised regarding healthcare personnel exposure, difficulty in collection, and patient discomfort. Viral RNA can also be detected in specimens such as saliva, blood, bronchoalveolar lavage fluid, sputum, faeces, and urine. This study aimed to provide updated information about the most suitable biological material to diagnose SARS-CoV-2, considering the risk assessment, specialization needed, test cost, complexity of the collection, and sample treatment associated with the different types of specimens. Methods: An extensive search of scientific review articles were made to collect information about the biological specimens to identify SARS-CoV-2 in the urine, sputum, nasopharyngeal, oropharyngeal, bronchoalveolar (BAL), saliva, faeces, and blood. For this purpose, an index score was developed based on seven categories: Materials and Equipment; Infection Risk for the Health Professional; Infection Risk for the Patient; Collection; Cost; Specialized HR; and RNA Extraction Type. Results and Discussion: Each criterion from the index score was quoted from 1.0 to 5.0, and a sum was made to classify which specimen is the best choice to diagnose SARS-CoV-2, according to the chosen parameters. Data indicated that urine specimens are the most elementary biological sample to access. Regarding RNA extraction, NPSs, OPS, and BAL presented the maximum score. However, BAL has the lowest score regarding associated costs. Concerning sputum and saliva, all the aspects were evaluated with a score of 5.0 except for the RNA Extraction Type in sputum. Regarding the total scores of the multiple specimens, the lowest corresponds to BAL with a score of 1.7, followed by blood with 3.1 and NPSs and OPS with 3.6 and 3.7, respectively. Urine and faeces have the same value, 4.4, sputum has 4.9, and the highest and maximum possible value corresponds to saliva with 5.0, making this last specimen the most suitable for all considered parameters. Conclusion: Although OPS and NPSs are the most used specimens, there are better alternatives. Among all the specimens of the respiratory system, saliva is the most cost-effective specimen for performing SARS-CoV-2 diagnosis. Even though these infections are usually diagnosed clinically based on symptoms and local epidemiology, identification of the specific pathogen may affect clinical management and be crucial for containing potential outbreaks.
- Effects of apigenin on gastric cancer cellsPublication . Pratas, Ana; Malhão, Beatriz; Palma, Raquel; Mendonça, Paula; Cervantes, Renata; Marques-Ramos, AnaGastric Cancer (GC) is one of the most prevalent cancers worldwide. As the currently available therapeutic options are invasive, new and more benign options are being explored. One of which is Apigenin (Api), a natural flavonoid found in fruits and vegetables, such as celery, parsley, garlic, bell pepper, and chamomile tea. Api has known anti-inflammatory, -oxidant, and -proliferative properties in several diseases, and its potential as an anticancer compound has been explored. Here we systematize the available data regarding the effects of Api on GC cells, in terms of cell proliferation, apoptosis, Helicobacter pylori (H. pylori) infection, and molecular targets. From the literature, it is possible to conclude that Api inhibits cell growth in a dose- and time-dependent manner, which is accompanied by the reduction of clone formation and induction of apoptosis. This occurs through the Akt/Bad/Bcl2/Bax axis that activates the mitochondrial pathway of apoptosis, resulting in the restriction of cell proliferation. Additionally, it seems that the anti-proliferative potential of Api on GC cells is particularly relevant in a more aggressive GC phenotype but can also affect normal gastric cells. This indicates that this flavonoid must be used in low-to-moderate doses to avoid side effects induced by disturbance of the normal epithelium. In H. Pylori-infected cells, the literature demonstrates that Api reduces inflammation by diminishing the levels of H. pylori colonization, preventing NF-kB activation, and diminishing the production of reactive oxygen specimens (ROS). Accordingly, GC Api seems to regulate different hallmarks of cancer, such as cell proliferation, apoptosis, cell migration, inflammation, and oxidative stress, demonstrating its potential as an anti-GC compound.
- Expression of mTOR in normal and pathological conditionsPublication . Marques-Ramos, Ana; Cervantes, RenataThe mechanistic/mammalian target of rapamycin (mTOR), a protein discovered in 1991, integrates a complex pathway with a key role in maintaining cellular homeostasis. By comprising two functionally distinct complexes, mTOR complex 1 (mTORC1) and mTORC2, it is a central cellular hub that integrates intra- and extracellular signals of energy, nutrient, and hormone availability, modulating the molecular responses to acquire a homeostatic state through the regulation of anabolic and catabolic processes. Accordingly, dysregulation of the mTOR pathway has been implicated in a variety of human diseases. While major advances have been made regarding the regulators and effectors of the mTOR signaling pathway, insights into the regulation of mTOR gene expression are beginning to emerge. Here, we present the currently available data regarding the mTOR expression regulation at the level of transcription, translation, and mRNA stability and systematize the current knowledge about the fluctuations of mTOR expression observed in several diseases, both cancerous and non-cancerous. In addition, we discuss whether mTOR expression changes can be used as a biomarker for diagnosis, disease progression, prognosis, and/or response to therapeutics. We believe that our study will contribute to the implementation of new disease biomarkers based on mTOR as it gives an exhaustive perspective on the regulation of mTOR gene expression in both normal and pathological conditions.
- GASMoC method: a phenol-free technique to detect acid-fast bacilliPublication . Gomes, A.; Amaral, P.; Santos, R.; Santos, S.; Tortosa, F.; Mendonça, Paula; Marques-Ramos, AnaThe genre Mycobacterium includes a series of pathological species, such as M. tuberculosis, which is important for pathology laboratories to detect for a correct diagnosis. The Ziehl-Neelsen technique (ZNT) is the most common histochemical method used to detect these bacilli and uses a heated mixture of carbol-fuchsine, which contains basic fuchsine and phenol. Whereas the former component is responsible for the pinkish staining of acid-fast mycobacteria, the role of phenol is not completely understood and it has been suggested that its exclusion does not impact the detection ability of the ZNT. Since phenol is highly toxic and induces several injuries, the goal of this study is to determine the detection capacity of mycobacteria through a method that excludes the use of phenol. Accordingly, the GASMoC method, a modified ZNT that employs a solution of aqueous basic fuchsine heated at 37 °C, was tested on histological samples positive for mycobacteria and the results were compared to that of the ZNT. Data demonstrated that the GASMoC method was able to detect acid-fast bacilli (AFB) in all analyzed cases. Remarkably, microscopic inspection of mycobacteria was easier when the GASMoC method was applied. In conclusion, our study demonstrates that AFB detection does not require phenol and that the GASMoC method, a phenol-free technique, may substitute the ZNT in pathology laboratories.
- Impact of particles on pulmonary endothelial cellsPublication . Almeida-Silva, Marina; Cardoso, Jéssica; Alemão, Catarina; Santos, Sara; Monteiro, Ana; Manteigas, Vítor; Marques-Ramos, AnaAccording to the WHO, air quality affects around 40 million people, contributing to around 21,000 premature deaths per year. Severe respiratory diseases, such as asthma and chronic obstructive pulmonary disorder, can be promoted by air pollution, which has already been documented; this is one of the reasons why air quality is a very relevant factor for human health and well-being. Aerosols are an aggregation of solid or liquid particles dispersed in the air and can be found in the form of dust or fumes. Aerosols can be easily inhaled or absorbed by the skin, leading to adverse health effects according to their sizes ranging from the nanometre to the millimeter scale. Based on the PRISMA methodology and using the Rayyan QCRI platform, it was possible to assess more than four hundred research articles. This systematic review study aimed to understand the impact of particles on pulmonary endothelial cells, namely particulate matter in different sizes, cigarette smoke, diesel exhaust particles, and carbon black. The main conclusions were that particles induce multiple health effects on endothelial cells, namely endothelial dysfunction, which can lead to apoptosis and necrosis, and it may also cause necroptosis in lung structure.
- Impacto do uso de fucsina básica aquosa na detecção de bacilos álcool-ácido resistentesPublication . Gomes, A.; Amaral, P.; Santos, R.; Santos, S.; Tortosa, F.; Mendonça, Paula; Marques-Ramos, AnaTuberculose - Infeção com maior mortalidade a nível mundial em 2016, causada pelo bacilo de Kock ou Mycobacterium tuberculosis. Técnica de Ziehl-Neelsen (ZN) - Evidenciar bacilos álcool-ácido resistentes (BAAR). Carbol-fucsina - Solução composta por fenol e fucsina básica. Objetivo geral do estudo - Determinar a capacidade de deteção da técnica de Ziehl-Neelsen sem o uso de fenol. Hipótese investigacional - Tendo por base dois estudos já realizados, é possível suprimir o fenol na técnica de ZN, através do uso de fucsina básica aquosa, sem afetar a capacidade de deteção de BAAR.
- Imunoterapia finalPublication . Marques-Ramos, AnaSistema Imunitário. Reconhecimento tumoral. Cancer Imunoediting. Evasão à imunidade inata. Evasão à imunidade adaptativa. Estratégias imunoterapia em cancro. CTLA-4. PD-1. Bloqueio dos checkpoints imunes. Regulação das células T. Anticorpos. Adoptive cell therapy. TIL. T cells expressing novel TCRs. Chimeric antigen receptor (CAR-T cells). Citoquinas. Vacinas. Vacinas com células dendríticas. Vacinas personalizadas com neoantigénios. Vacinas oncolíticas. Monitorização do sistema imunitário. Sangue periférico.
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