The main objective of this study was to develop a polymeric drug delivery system for paclitaxel, intended to be intravenously administered, capable of improving the therapeutic index of the drug and devoid of the adverse effects of Cremophor EL. To achieve this goal paclitaxel (Ptx)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (Ptx-PLGA-Nps) were prepared by the interfacial deposition method. The influence of different experimental parameters on the incorporation efficiency of paclitaxel in the nanoparticles was evaluated. Our results demonstrate that the incorporation efficiency of paclitaxel in nanoparticles was mostly affected by the method of preparation of the organic phase and also by the organic phase/aqueous phase ratio. Our data indicate that the methodology of preparation allowed the formation of spherical nanometric (<200 nm), homogeneous and negatively charged particles which are suitable for intravenous administration. The release behaviour of paclitaxel from the developed Nps exhibited a biphasic pattern characterised by an initial fast release during the first 24 h, followed by a slower and continuous release. The in vitro anti-tumoral activity of Ptx-PLGA-Nps developed in this work was assessed using a human small cell lung cancer cell line (NCI-H69 SCLC) and compared to the in vitro anti-tumoral activity of the commercial formulation Taxol. The influence of Cremophor EL on cell viability was also investigated. Exposure of NCI-H69 cells to 25 microg/ml Taxol resulted in a steep decrease in cell viability. Our results demonstrate that incorporation of Ptx in nanoparticles strongly enhances the cytotoxic effect of the drug as compared to Taxol, this effect being more relevant for prolonged incubation times.
Strategies used to enhance liposome-mediated drug delivery in vivo include the enhancement of stability and circulation time in the bloodstream, targeting to specific tissues or cells, and facilitation of intracytoplasmic delivery. pH-sensitive liposomes have been developed to mediate the introduction of highly hydrophilic molecules or macromolecules into the cytoplasm. These liposomes destabilize under acidic conditions found in the endocytotic pathway, and usually contain phosphatidylethanolamine (PE) and titratable stabilizing amphiphiles. Formulations without PE have also been developed. Encapsulated compounds are thought to be transported into the cytoplasm through destabilization of or fusion with the endosome membrane. Incorporation of a low mole percentage of poly(ethylene glycol) (PEG)-conjugated lipids into pHsensitive liposomes confers prolonged circulation times to these liposomes, which are otherwise cleared rapidly. While the incorporation of PEG -lipids reduces the pH-dependent release of encapsulated fluorescent markers in vitro, it does not hinder the cytoplasmic delivery of the markers per cell-associated liposome. This suggests that intracellular delivery is not dictated simply by the destabilization of the liposomes. Antibodies or ligands to cell surface receptors can be coupled to pH-sensitive or sterically stabilized pH-sensitive liposomes for targeting. pH-sensitive liposomes have been used to deliver anticancer drugs, antibiotics, antisense oligonucleotides, ribozymes, plasmids, proteins and peptides to cells in culture or in vivo. D
We have demonstrated four novel mutations of the BSCL2 and AGPAT2 genes responsible for Berardinelli-Seip syndrome and Brunzell syndrome (AGPAT2-related syndrome).
Introduction: To report the first case of a serpiginous choroiditis presenting after SARS-CoV-2 infection in a previously healthy young woman. Case description: A 41-year-old woman reported blurry vision OS 1 month after a mild SARS-CoV-2 infection. Left eye fundus examination revealed multiple peripapillary atrophic lesions, adjacent to a larger diffuse, ill-defined, yellow-whitish deep amoeboid-like patch, involving the peripapillary region and extending temporally to the fovea. Multimodal imaging including fluorescein angiography, indocyanine-green angiography, fundus autofluorescence and optical coherence tomography was consistent with serpiginous choroiditis. A complete systemic work-up was performed to exclude potential infectious or inflammatory etiologies. The active choroidal lesions responded to high dose corticosteroids, with functional improvement. Immunomodulatory therapy with methotrexate was initiated for long-term management. Conclusion: Serpiginous choroiditis is a rare but important sight-threatening condition that has been previously associated to viral infections, which seem to have a role in the induction and/or perpetuation of choroidal inflammation. SARS-CoV-2 infection appears to have played a role as a possible trigger for intraocular inflammation in this case. Therefore, COVID-19 patients reporting visual symptoms should be carefully evaluated in order to obtain adequate ophthalmological management to avoid irreversible visual damage.
JUSTIFICATIVA E OBJETIVOS: Apesar da investigação contínua e do desenvolvimento de novos fármacos e técnicas, as náuseas e vômitos no pós-operatório (NVPO) são CONCLUSÕES: Embora o manuseio de NVPO tenha m e l h o r a d o n o s ú l t i m o s a n o s , e s t e s a i n d a o c o r r e m
Background Uveal melanoma (UM) is the most common intraocular tumor in adults. Despite good primary tumor control, up to 50% of patients develop metastasis, which is lethal. UM often presents asymptomatically and is usually diagnosed by clinical examination and imaging, making it one of the few cancer types diagnosed without a biopsy. Hence, alternative diagnostic tools are needed. Circulating tumor DNA (ctDNA) has shown potential as a liquid biopsy target for cancer screening and monitoring. The aim of this study was to evaluate the feasibility and clinical utility of ctDNA detection in UM using specific UM gene mutations. Methods We used the highly sensitive digital droplet PCR (ddPCR) assay to quantify UM driver mutations (GNAQ, GNA11, PLCβ4 and CYSTLR2) in cell-free DNA (cfDNA). cfDNA was analyzed in six well established human UM cell lines with known mutational status. cfDNA was analyzed in the blood and aqueous humor of an UM rabbit model and in the blood of patients. Rabbits were inoculated with human UM cells into the suprachoroidal space, and mutated ctDNA was quantified from longitudinal peripheral blood and aqueous humor draws. Blood clinical specimens were obtained from primary UM patients (n = 14), patients presenting with choroidal nevi (n = 16) and healthy individuals (n = 15). Results The in vitro model validated the specificity and accuracy of ddPCR to detect mutated cfDNA from UM cell supernatant. In the rabbit model, plasma and aqueous humor levels of ctDNA correlated with tumor growth. Notably, the detection of ctDNA preceded clinical detection of the intraocular tumor. In human specimens, while we did not detect any trace of ctDNA in healthy controls, we detected ctDNA in all UM patients. We observed that UM patients had significantly higher levels of ctDNA than patients with nevi, with a strong correlation between ctDNA levels and malignancy. Noteworthy, in patients with nevi, the levels of ctDNA highly correlated with the presence of clinical risk factors. Conclusions We report, for the first time, compelling evidence from in vitro assays, and in vivo animal model and clinical specimens for the potential of mutated ctDNA as a biomarker of UM progression. These findings pave the way towards the implementation of a liquid biopsy to detect and monitor UM tumors.
-Background -Protein-calorie malnutrition is common in chronic liver disease (CLD) but adequate clinical tools for nutritional assessment are not defined. Objective -In CLD patients, it was aimed: 1. Characterize protein-calorie malnutrition; 2. Compare several clinical, anthropometric and functional tools; 3. Study the association malnutrition/CLD severity and malnutrition/outcome. Methods -Observational, prospective study. Consecutive CLD ambulatory/hospitalised patients were recruited from 01-03-2012 to 31-08-2012, studied according with age, gender, etiology, alcohol consumption and CLD severity defined by Child-Turcotte-Pugh. Nutritional assessment used subjective global assessment, anthropometry, namely body-mass index (BMI), triceps skinfold, mid upper arm circumference, mid arm muscular circumference and handgrip strength. Patients were followed during two years and survival data was recorded. Results -A total of 130 CLD patients (80 men), aged 22-89 years (mean 60 years) were included. Most suffered from alcoholic cirrhosis (45%). Hospitalised patients presented more severe disease (P<0.001) and worst nutritional status defined by BMI (P=0.002), mid upper arm circumference (P<0.001), mid arm muscular circumference (P<0.001), triceps skinfold (P=0.07) and subjective global assessment (P<0.001). A third presented deficient/low handgrip strength. Alcohol consumption (P=0.03) and malnutrition detected by BMI (P=0.03), mid upper arm circumference (P=0.001), triceps skinfold (P=0.06), mid arm muscular circumference (P=0.02) and subjective global assessment (P<0.001) were associated with CLD severity. From 25 patients deceased during follow-up, 17 patients were severely malnourished according with triceps skinfold. Malnutrition defined by triceps skinfold predicted mortality (P<0.001). Conclusion -Protein-calorie malnutrition is common in CLD patients and alcohol plays an important role. Triceps skinfold is the most efficient anthropometric parameter and is associated with mortality. Nutritional assessment should be considered mandatory in the routine care of CLD patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.