67 research outputs found
Selection of aptamers against triple negative breast cancer cells using high throughput sequencing
Triple-negative breast cancer is the most aggressive subtype of invasive breast cancer with a poor prognosis and no approved targeted therapy. Hence, the identification of new and specific ligands is essential to develop novel targeted therapies. In this study, we aimed to identify new aptamers that bind to highly metastatic breast cancer MDA-MB-231 cells using the cell-SELEX technology aided by high throughput sequencing. After 8 cycles of selection, the aptamer pool was sequenced and the 25 most frequent sequences were aligned for homology within their variable core region, plotted according to their free energy and the key nucleotides possibly involved in the target binding site were analyzed. Two aptamer candidates, Apt1 and Apt2, binding specifically to the target cells with Kd values of 44.3 ± 13.3 nM and 17.7 ± 2.7 nM, respectively, were further validated. The binding analysis clearly showed their specificity to MDA-MB-231 cells and suggested the targeting of cell surface receptors. Additionally, Apt2 revealed no toxicity in vitro and showed potential translational application due to its affinity to breast cancer tissue sections. Overall, the results suggest that Apt2 is a promising candidate to be used in triple-negative breast cancer treatment and/or diagnosis. © 2021, The Author(s).Tis study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of
the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004)
funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional
Regional do Norte. Débora Ferreira (DF) is the recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020—Programa Operacional Regional do Norte. Joaquim Barbosa (JB) and Diana A. Sousa (DAS) acknowledge FCT for the Grants SFRH/BD/51109/2010 and PD/BD/139083/2018, respectively.info:eu-repo/semantics/publishedVersio
Foraminifera as health bioindicators in nearshore and offshore Brazilian coral reef sediments
Abstrac
Anopheles aquasalis transcriptome reveals autophagic responses to Plasmodium vivax midgut invasion
BACKGROUND: Elimination of malaria depends on mastering transmission and understanding the biological basis of Plasmodium infection in the vector. The first mosquito organ to interact with the parasite is the midgut and its transcriptomic characterization during infection can reveal effective antiplasmodial responses able to limit the survival of the parasite. The vector response to Plasmodium vivax is not fully characterized, and its specificities when compared with other malaria parasites can be of fundamental interest for specific control measures. METHODS: Experimental infections were performed using a membrane-feeding device. Three groups were used: P. vivax-blood-fed, blood-fed on inactivated gametocytes, and unfed mosquitoes. Twenty-four hours after feeding, the mosquitoes were dissected and the midgut collected for transcriptomic analysis using RNAseq. Nine cDNA libraries were generated and sequenced on an Illumina HiSeq2500. Readings were checked for quality control and analysed using the Trinity platform for de novo transcriptome assembly. Transcript quantification was performed and the transcriptome was functionally annotated. Differential expression gene analysis was carried out. The role of the identified mechanisms was further explored using functional approaches. RESULTS: Forty-nine genes were identified as being differentially expressed with P. vivax infection: 34 were upregulated and 15 were downregulated. Half of the P. vivax-related differentially expressed genes could be related to autophagy; therefore, the effect of the known inhibitor (wortmannin) and activator (spermidine) was tested on the infection outcome. Autophagic activation significantly reduced the intensity and prevalence of infection. This was associated with transcription alterations of the autophagy regulating genes Beclin, DRAM and Apg8. CONCLUSIONS: Our data indicate that P. vivax invasion of An. aquasalis midgut epithelium triggers an autophagic response and its activation reduces infection. This suggests a novel mechanism that mosquitoes can use to fight Plasmodium infection.publishersversionpublishe
The Portfolio as an Evaluation Tool: an Analysis of its Use in an Undergraduate Nursing Program
This qualitative study was carried out between April and August 2007. It analyzed the use of portfolios in the academic community. A total of nine full-time professors and 119 students enrolled in their third semester were interviewed through a semi-structured interview. Content analysis was used to analyze data. Learning evaluations are seen as a verification of knowledge and efficacy of pedagogical method, and also as an incentive to study. Evaluations are procedural, that is, evaluation is continuous, or one-time, e.g. semester end tests. The portfolio is defined as a gradual and continuous evaluation tool. The faculty members and students need to accept the use of portfolios and evaluate the possibilities of this resource. This study is a first attempt to appraise the evaluation process of an undergraduate program, and the use of portfolios and other strategies needs to be consolidated in order to improve the educational process in undergraduate nursing programs.Se trata de un estudio cualitativo, realizado en el período de abril a agosto de 2007. El objetivo fue analizar la utilización del portafolio por la comunidad académica. Se entrevistó a través de un guión a nueve docentes efectivos y 119 discentes matriculados a partir del tercer período. En el análisis de datos se utilizó el análisis de contenido. La evaluación del aprendizaje es considerada como verificación del conocimiento, como eficacia del método pedagógico e incentivo al estudio. Con relación al tipo de evaluación son procesuales y puntuales. El portafolio es definido como un instrumento de evaluación gradual y continuo. Es necesario que el cuerpo docente y discente acepte experimentar la utilización del portafolio y así evaluar las posibilidades de este recurso. Representa una primera aproximación al proceso de evaluación en la graduación y de esa forma el portafolio y otras estrategias necesitan ser consolidadas de forma a mejorar el proceso de formación en la graduación de enfermería.Este é um estudo qualitativo, realizado no período de abril a agosto de 2007. O objetivo foi analisar a utilização do portfólio pela comunidade acadêmica. Entrevistaram-se, através de um roteiro, nove docentes efetivos e 119 discentes matriculados a partir do terceiro período. Na análise de dados utilizou-se da análise de conteúdo. A avaliação da aprendizagem é considerada como verificação do conhecimento, como eficácia do método pedagógico e incentivo ao estudo. Com relação aos tipos de avaliação são eles processuais e pontuais. O portfólio é definido como instrumento de avaliação gradual e contínuo. É necessário que o corpo docente e discente aceite experimentar a utilização do portfólio e assim avaliar as possibilidades desse recurso. Representa a primeira aproximação ao processo de avaliação na graduação e, dessa forma, o portfólio e outras estratégias precisam ser consolidadas de forma a melhorar o processo de formação na graduação de enfermagem
Glutamine dipeptide supplementation improves clinical responses in patients with diabetic foot syndrome
ABSTRACT The effect of glutamine dipeptide (GDP) supplementation in patients with diabetic foot syndrome was evaluated. A total of 22 patients took part in the study. GDP was supplied in 10 g sachets, and was dissolved in water immediately before use, with ingestion once a day, after lunch or after dinner (20 g/day) over a period of 30 days. Quantification of foot insensitive areas, oxidative stress, blood cytokines, and biochemical, hematological and toxicological parameters was performed before and after GDP supplementation. We observed an increase in blood levels of interferon-α (P=0.023), interferon-γ (P=0.038), interleukin-4 (P=0.003), interleukin-6 (P=0.0025), interleukin-7 (P=0.028), interleukin-12 p40 (P=0.017), interleukin-13 (P=0.001), leukocytes (P=0.037), eosinophils (P=0.049), and typical lymphocytes (P<0.001) due to GDP administration. In addition, we observed a reduced number (P=0.048) of insensitive areas on the foot, and reduction (P=0.047) of fasting hyperglycemia. Patients also showed increased blood high density lipoprotein (P<0.01) and protein thiol groups (P=0.004). These favorable results were associated with the absence of renal and hepatic toxicity. These results are of clinical relevance, since supplementation with GDP over 30 days improved clinical responses in patients with diabetic foot syndrome
A cyclopalladated complex interacts with mitochondrial membrane thiol-groups and induces the apoptotic intrinsic pathway in murine and cisplatin-resistant human tumor cells
<p>Abstract</p> <p>Background</p> <p>Systemic therapy for cancer metastatic lesions is difficult and generally renders a poor clinical response. Structural analogs of cisplatin, the most widely used synthetic metal complexes, show toxic side-effects and tumor cell resistance. Recently, palladium complexes with increased stability are being investigated to circumvent these limitations, and a biphosphinic cyclopalladated complex {Pd<sub>2 </sub>[<it>S<sub>(-)</sub></it>C<sup>2</sup>, N-dmpa]<sub>2 </sub>(μ-dppe)Cl<sub>2</sub>} named C7a efficiently controls the subcutaneous development of B16F10-Nex2 murine melanoma in syngeneic mice. Presently, we investigated the melanoma cell killing mechanism induced by C7a, and extended preclinical studies.</p> <p>Methods</p> <p>B16F10-Nex2 cells were treated <it>in vitro </it>with C7a in the presence/absence of DTT, and several parameters related to apoptosis induction were evaluated. Preclinical studies were performed, and mice were endovenously inoculated with B16F10-Nex2 cells, intraperitoneally treated with C7a, and lung metastatic nodules were counted. The cytotoxic effects and the respiratory metabolism were also determined in human tumor cell lines treated <it>in vitro </it>with C7a.</p> <p>Results</p> <p>Cyclopalladated complex interacts with thiol groups on the mitochondrial membrane proteins, causes dissipation of the mitochondrial membrane potential, and induces Bax translocation from the cytosol to mitochondria, colocalizing with a mitochondrial tracker. C7a also induced an increase in cytosolic calcium concentration, mainly from intracellular compartments, and a significant decrease in the ATP levels. Activation of effector caspases, chromatin condensation and DNA degradation, suggested that C7a activates the apoptotic intrinsic pathway in murine melanoma cells. In the preclinical studies, the C7a complex protected against murine metastatic melanoma and induced death in several human tumor cell lineages <it>in vitro</it>, including cisplatin-resistant ones. The mitochondria-dependent cell death was also induced by C7a in human tumor cells.</p> <p>Conclusions</p> <p>The cyclopalladated C7a complex is an effective chemotherapeutic anticancer compound against primary and metastatic murine and human tumors, including cisplatin-resistant cells, inducing apoptotic cell death via the intrinsic pathway.</p
Brazilian Morus nigra
Morus nigra has been used popularly for several proposes, including diabetic. In an attempt to support medicinal value, the acute hypoglycemic, hypolipidemic, and antioxidant effects of the ethanolic extract of Morus nigra (EEMn 200 or 400 mg/kg b.w.) were evaluated in normal and alloxan-induced diabetic treated for 14 days. Serum biochemical and antioxidant analysis were performed at the end of experiment. Oral glucose tolerance test was performed at 10th and 15th days. Chromatographic analysis by HPLC-DAD of EEMn was performed. Insulin was used as positive control to glycemic metabolism as well as fenofibrate to lipid metabolism. EEMn (400 mg/kg/day) reduced fasting and postprandial glycaemia, improved oral glucose tolerance, and reduced lipolysis and proteolysis in diabetic rats. EEMn decreased the blood levels of total cholesterol and increased HDL level when compared to the diabetic control rats. At higher levels, EEMn reduced triglycerides and VLDL levels in diabetic rats. Also, EEMn reduced malondialdehyde and increased the reduced glutathione levels in liver of diabetic rats. Chromatographic analysis identified the presence of the flavonoids rutin, isoquercetin, and kaempferitrin. Acute EEMn treatment reduced hyperglycemia, improved oral glucose tolerance, and minimized dyslipidemia and oxidative stress leading to a reduction in atherogenic index in alloxan-induced diabetic rats
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