22 research outputs found

    Does mesenchymal stem cell improve the liver regeneration after the 70% hepatectomy?]

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    Purpose: To evaluate the effects of mesenchymal stem cells on liver regeneration in rats following a 70% hepatectomy. Methods: Forty rats were subjected to 70% hepatectomy and then similar to 10(6) mesenchymal stem cells (test group), or saline solution (control group), were infused into their livers via the portal vein. Each treatment group was divided into early and late subgroups (euthanized 3 d and 5 d following the operation, respectively). Group comparisons of Albumin, aminotransaminases (AST, ALT), and Alcaline Phosphatase (AP) levels, proliferative index (ki-67+ straining), and mitotic cell counts were conducted. Results: No significant differences in liver regeneration rate, number of mitoses, proliferative index, or serum levels of albumin, AST, or AP were observed. ALT levels were higher in the test group than in the control group (p<.05). Conclusions: Mesenchymal stem-cell therapy did not improve liver regeneration rate 3 d or 5 d after 70% hepatectomy in rats. Likewise, the therapy appeared not to affect liver function, proliferative index, or number of mitoses significantly.Univ Fed Sao Paulo UNIFESP, Postgrad Program Interdisciplinary Surg Sci, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Pathol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Surg, Div Surg Gastroenterol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Postgrad Program Interdisciplinary Surg Sci, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Pathol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Surg, Div Surg Gastroenterol, Sao Paulo, SP, BrazilWeb of Scienc

    SARS-CoV-2 Variants and Vaccines.

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    Viral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based

    Preclinical safety and the regulatory implications for design and development of polymer therapeutics

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    Since the early 1990s polymer-protein conjugates (included PEGylated enzymes and cytokines), polymeric drugs and polymeric sequestrants have been entering the market as innovative polymer-based therapeutics. Initially these products were most frequently developed as novel anticancer agents; indeed they can be considered first generation "nanomedicines". More recently, a much broader range of life-threatening and debilitating diseases (e.g. viral infections, arthritis, multiple sclerosis and hormone abnormalities) have been targeted via intravenous (i.v.), subcutaneous (s.c.) or oral routes of administration. Given the increasing novelty of polymeric materials proposed for development as second-generation polymer therapeutics (with increasing complexity of conjugate composition), and the growing debate as to the safety of nanomedicines per se, the need for evolution of an appropriate regulatory framework is at the forefront of the scientific discussion. The adequacy of the current tests and models used to define safety are also constantly being reviewed. Here we describe the current status and future challenges in relation to these issues. (C) 2009 Elsevier B.V. All rights reserved.. - EPSRC [EP/C 013220/1]. - RG would like to thank iMed.UL and FCT for financial support. RD would like to acknowledge support from EPSRC platform grant No. EP/C 013220/1

    Optimization of protein loaded PLGA nanoparticles manufacturing parameters following a quality-by-design approach

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    V. Sainz, et al, 'Optimization of protein loaded PLGA nanoparticle manufacturing parameters following a quality-by-design approach', RSC Advances, Vol 6 (106): 104502-104512, October 2016, available online at doi: 10.1039/C6RA19092H. Published by the Royal Society of Chemistry.Development of a multivariate-based regression model for estimating the critical attributes for establishing a design-space for poly(lactic-co-glycolic acid) (PLGA) nanoparticles formulated by a double emulsion-solvent evaporation method. Three-level, full factorial experimental design to assess the impact of three different manufacturing conditions (polymer viscosity, surfactant concentration and amount of model antigen ovalbumin) on five critical particle attributes (zeta potential, polydispersity index, hydrodynamic diameter, loading capacity and entrapment efficiency). The optimized formulation was achieved with a viscosity of 0.6 dl/g, surfactant concentration of 11 % (w/v) in the internal phase and 2.5 % (w/w) of ovalbumin. The design-space that is satisfied for nanoparticles with the targeted attributes was obtained with a polymer viscosity between 0.4 and 0.9 dl/g, surfactant concentration ranging from 8 to 15 % (w/v) and 2.5 % (w/w) of ovalbumin. The nanoparticles were spherical and homogenous and were extensively taken up by JAWS II murine immature dendritic cells without affecting the viability of these phagocytic cells. Better understanding was achieved by multivariate regression to control process manufacturing to optimize PLGA nanoparticle formulation. Utilization of multivariate regression with a defined control space is a good tool to meet product specifications, particularly over a narrow variation range.Peer reviewe

    Cloreto de sódio a 0,9%, adicionado ou não de dexametasona, intrapleural, na prevenção de aderências pulmonares após toracotomia intercostal em cães

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    Pulmonary adhesions in dogs are a common sequel after surgical intervention, undermining any interventions. This study aimed to determine in dogs, the efficacy of sodium chloride solution 0.9% with or without dexamethasone in order to prevent adhesions after intercostal thoracotomy. Fifteen dogs were separated into three groups of five animals, A, B and C and underwent thoracotomy in the fifth left intercostal space. Three other dogs were submitted to a previous study. In the dogs of Group A it was performed only a thoracotomy and thoracorraphy; in group B, it was performed a thoracotomy, thoracorraphy and injection into the pleural cavity of isotonic sodium chloride (10ml) and dexamethasone (1mg kg-1). In the dogs of the group C, it was performed the thoracotomy thoracorraphy and injected isotonic sodium chloride (10ml kg-1) into the pleural cavity. After 15 days of thoracotomy, it was performed transdiaphragmatic thoracocospy to determine the presence and score of adhesions between the lung and chest wall. The results demonstrated the presence of adhesions in the majority of group A and reduced or no adhesions in the other groups. For statistical evaluation, it was pplied the chi-square test with significance level of 5% (P≤0.05). The sodium chloride solution 0.9% with or without dexamethasone in the pleural space prevented or reduced lung adhesions after intercostal thoracotomy
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