Browsing by Author "Silva, Diana Dias da"
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- Influence of puncture devices on the accuracy of cyclophosphamide dosing for chemotherapy administrationPublication . Carvalho, Susana; Cardoso, Andreia; Ferreira, Débora; Silva, Diana Dias da; Moreira, Fernando; Moreira, Fernando; Dias da Silva, Diana CristinaCyclophosphamide is one of the most commonly used cytotoxic drugs in chemotherapy protocols. Its preparation in the hospital setting involves handling concentrated solutions, which pose occupational exposure risks and potential variations in the final dose administered. The aim of this study was to evaluate the effect of aspiration devices on the concentration of cyclophosphamide in reconstituted solutions. An analytical method was validated using high-performance liquid chromatography coupled to a diode-array detector (HPLC-DAD) for quality control. Cyclophosphamide solutions were prepared and aspirated using either a conventional needle or spike device with or without a filtration system. The validated method demonstrated linearity (R2 = 0.9999), high precision (0.22–4.59%) and accuracy (88.9–99.4%), with a limit of quantification of 4.03 µg/mL. Significant differences (p < 0.001) were observed between samples aspirated with a needle and those aspirated with a spike fitted with a 5 µm filter, with the latter showing lower cyclophosphamide concentrations, suggesting partial retention of the drug. No significant differences were found between the needle and filterless spike preparations. These results suggest that the choice of aspiration device influences the final drug concentration, potentially affecting therapeutic efficacy. Standardisation of preparation techniques and an awareness of device limitations are essential to ensure accurate chemotherapy dosing and patient safety.
- Mexican calea (Calea zacatechichi Schltdl.) interferes with cholinergic and dopaminergic pathways and causes neuroglial toxicityPublication . Garcia, Maria Rita; Gil-Izquierdo, Ángel; Ferreres, Federico; Andrade, Paula B.; Mineiro, Tiago; Seabra, Vítor; Videira, Romeu A.; Silva, Diana Dias da; Gomes, Nelson G.M.; Dias da Silva, Diana CristinaThe use of “Mexican calea” (Calea zacatechichi Schltdl.) in ritualistic ceremonies, due to its dream-inducing effects, was until recently limited to indigenous communities in Mexico. However, the plant has recently gained popularity in Western societies being commonly used in recreational settings. Despite the traditional and recreational uses, mechanisms underlying its reported oneirogenic effects remain unknown, with no data available on its neurotoxic profile. The scarcity of toxicological data and the unknown role of major neurotransmitter systems in the dream-inducing properties of the plant prompted us to investigate which neurotransmitters might be affected upon its consumption, as well as the potential cytotoxic effects on neurons and microglial cells. Furthermore, we aimed to explore a relationship between the recorded effects and specific constituents. Effects on cholinergic and monoaminergic pathways were investigated using enzymatic assays, with the latter also being conducted in neuronal SH-SY5Y cells along with the impact on glutamate-induced excitotoxicity. Investigation of the neurotoxic profile was approached in neuronal SH-SY5Y and microglial BV-2 cells, evaluating effects on metabolic performance and membrane integrity using MTT and LDH leakage assays, respectively. Potential interference with oxidative stress was monitored by assessing free radical's levels, as well as 5-lipoxygenase mediated lipid peroxidation. Phenolic constituents were identified through HPLC-DAD-ESI(Ion Trap)MSn analysis. Based on the significant inhibition upon acetylcholinesterase (p < 0.05) and tyrosinase (IC50 = 60.87 ± 7.3 μg/mL; p < 0.05), the aqueous extract obtained from the aerial parts of C. zacatechichi interferes with the cholinergic and dopaminergic systems, but has no impact against monoamine oxidase A. Additionally, a notable cytotoxic effect was observed in SH-SY5Y and BV-2 cells at concentrations as low as 125 and 500 μg/mL (p < 0.05), respectively, LDH leakage suggesting apoptosis may occur at these concentrations, with necroptosis observed at higher ones. Despite the neurocytotoxic profile, these effects appear to be independent of radical stress, as the C. zacatechichi extract scavenged nitric oxide and superoxide radicals at concentrations as low as 62.5 μg/mL, significantly inhibiting also 5-lipoxygenase (IC50 = 72.60 ± 7.3 μg/mL; p < 0.05). Qualitative and quantitative analysis using HPLC-DAD-ESI(Ion Trap)MSn enabled the identification of 28 constituents, with 24 of them being previously unreported in this species. These include a series of dicaffeoylquinic, caffeoylpentoside, and feruloylquinic acids, along with 8 flavonols not previously known to occur in the species, mainly 3-O-monoglycosylated derivatives of quercetin, kaempferol, and isorhamnetin. Our findings regarding the neuroglial toxicity elicited by C. zacatechichi emphasize the necessity for a thorough elucidation of the plant's toxicity profile. Additionally, evidence is provided that the aerial parts of the plant inhibit both acetylcholinesterase and tyrosinase, potentially linking its psychopharmacological effects to the cholinergic and dopaminergic systems, with an apparent contribution from specific phenolic constituents previously unknown to occur in the species. Collectively, our results lay the groundwork for a regulatory framework on the consumption of C. zacatechichi in recreational settings and contribute to elucidating previous contradictory findings regarding the mechanisms underlying the dream-inducing effects of the plant.
- Sequencing technologies in forensic microbiology: current trends and advancementsPublication . Oliveira, Manuela; Dias da Silva, Diana Cristina; Marszałek, Kamila; Kowalski, Michał; Frolova, Alina; Łabaj, Paweł P.; Branicki, Wojciech; Carvalho, Áurea Madureira; Silva, Diana Dias da; Oliveira, Ricardo Jorge DinisForensic microbiology is a subject of interest and research development across the forensic community. Studies of pathogen outbreaks, biocrime or bioterrorism attacks, and analyses of crime scenes fall within this field. Significant progress has been made in evolving DNA sequencing technologies in recent decades. These newly emerged transformative tools have become available to both biomedicine and forensics. Based on the published literature, this review provides an overview of the current trends and developments of NGS (next-generation sequencing) technologies applied to forensic microbiology. These new methods present numerous advantages over traditional sequencing technology and are useful in several practical applications within this forensic field. This article then examines the main challenges and limitations of this technology in forensics, providing a comprehensive review of NGS technology capabilities in expanding the precision and effectiveness of microbial forensic investigations—with the aim of inspiring scientists, forensic experts, lawyers, public health professionals, and policymakers alike to approach this newly powerful sequencing tool appropriately.