Biology subjects

Martins, P.

Publications and source records attributed to Martins, P..

4 recordsLinked to original sources

bioRxiv2025

Real-Time Viability Assessment of Ex Vivo Mouse Kidneys for Transplant Applications Using Dynamic Optical Coherence Tomography

Kidney transplantation remains the preferred treatment for patients with end-stage kidney disease. However, the ongoing shortage of donor organs continues to limit the availability of transplant treatments. Existing evaluation methods, such as the kidney donor profile index (KDPI) and pre-transplant donor biopsy (PTDB), have various limitations, including low discriminative power, invasiveness, and sampling errors, which reduce their effectiveness in organ quality assessment and contribute to the risk of unnecessary organ discard. In this study, we explored the dynamic optical coherence tomography (DOCT) as a real-time, non-invasive approach to monitor the viability of ex vivo mouse kidneys during static cold storage over 48 hours. The dynamic metrics logarithmic intensity variance (LIV), early OCT correlation decay speed (OCDSe), and late OCT correlation decay speed (OCDSl) were extracted from OCT signal fluctuations to quantify temporal and spatial tissue activity and deterioration. Our results demonstrate that DOCT provides complementary functional information to morphological assessment offered by conventional OCT imaging, showing potential to improve pre-transplant organ evaluation and clinic decision-making.

bioengineering↗

bioRxiv2024

Photoprotective mechanisms in Elysia species hosting Acetabularia chloroplasts shed light on host-donor compatibility in photosynthetic sea slugs

Sacoglossa sea slugs have garnered attention due to their ability to retain intracellular functional chloroplasts from algae, while degrading other algal cell components. While protective mechanisms that limit oxidative damage under excessive light are well documented in plants and algae, the photoprotective strategies employed by these photosynthetic sea slugs remain unresolved. Species within the genus Elysia are known to retain chloroplasts from various algal sources, but the extent to which the metabolic processes from the donor algae can be sustained by the sea slugs is unclear. By comparing their responses to high light conditions through kinetic analyses, molecular techniques, and biochemical assays, this study highlights significant differences between two photosynthetic Elysia species with chloroplasts derived from the green alga Acetabularia acetabulum. Notably, Elysia timida displayed remarkable tolerance to high light stress and sophisticated photoprotective mechanisms such as an active xanthophyll cycle, efficient D1 protein recycling, accumulation of heat-shock proteins and -tocopherol. In contrast, Elysia crispata exhibited absence or limitations in these photoprotective strategies. Our findings emphasize the intricate relationship between the host animal and the stolen chloroplasts, highlighting different capacities to protect the photosynthetic organelle from oxidative damage.

plant biology↗

bioRxiv2018

Isavuconazole therapeutic drug monitoring associated to a pharmacogenetic exploration is far from being a pharmacologists’ whim

Isavuconazole is a new antifungal prodrug to treat invasive aspergillosis and mucormycosis, theoretically not requiring drug monitoring. However, we reported 4 clinical cases with toxic concentrations. Based on Desais population pharmacokinetic model, we estimated patients kinetic profile. Clearance was abnormally low, likely related to CYP3A4/5 polymorphisms. Thus, we recommend to collect blood sample just before the first maintenance dose to estimate pharmacokinetic profile and individualized dose. For patients presenting high concentrations, pharmacogenetics can be done.

pharmacology and toxicology↗

bioRxiv2017

Vermont: a multi-perspective visual interactiveplatform for mutational analysis

BackgroundA huge amount of data about genomes and sequence variation is available and continues to grow on a large scale, which makes experimentally characterizing these mutations infeasible regarding disease association and effects on protein structure and function. Therefore, reliable computational approaches are needed to support the understanding of mutations and their impacts. Here, we present VERMONT 2.0, a visual interactive platform that combines sequence and structural parameters with interactive visualizations to make the impact of protein point mutations more understandable.\n\nResultsWe aimed to contribute a novel visual analytics oriented method to analyze and gain insight on the impact of protein point mutations. To assess the ability of VERMONT to do this, we visually examined a set of mutations that were experimentally characterized to determine if VERMONT could identify damaging mutations and why they can be considered so.\n\nConclusionsVERMONT allowed us to understand mutations by interpreting position-specific structural and physicochemical properties. Additionally, we note some specific positions we believe have an impact on protein function/structure in the case of mutation.

bioinformatics↗