443 research outputs found
Laccases stabilization with phosphatidylcholine liposomes
In recent years, there has been an upsurge of interest in enzyme treatment of textile fibres.
Enzymes are globular proteins whose catalytic function is due to their three dimensional structure. For this reason, stability strategies make use of compounds that avoid dismantling or distorting protein 3D structures. This study is concerned with the use of microencapsulation techniques to optimize enzyme stabilization. Laccases were embedded in phophatidylcholine
liposomes and their encapsulation capacity was assessed. Their enzymatic activity and stability were analyzed, comparing free-enzymes, enzymes in liposomes, and the lipid fraction separated from the aqueous fraction. An increase in their encapsulation efficiency was found at higher lipid/laccase ratios. Relative activity of enzyme-containing vesicles has also been shown
to be retained much more than that of free native enzymes. The loss of activity of laccases entrapped in the vesicles in the total stability process is lower than 10% compared with 40% to 60% of loss of free-laccases after heating the samples for 3 days. Laccase stabilization could
be of interest to future textile or cosmetic applications because of their potential for environmentally friendly oxidation technologies
Shock Following Subcutaneous Injections of Polymethylmethacrylate
info:eu-repo/semantics/publishedVersio
SÃndrome HemolÃtico Urémico AtÃpico en Cuidados Intensivos: Caso ClÃnico de un Adulto
info:eu-repo/semantics/publishedVersio
Ultrasound-assisted biosynthesis of novel methotrexate-conjugates
New methotrexate-acylglycerols and methotrexate-cyclodextrins (, and -CD) conjugates were obtained via esterification or transesterification reactions. All reactions were catalysed by esterases namely immobilized Lipase from Candida antarctica B and Lipase from Thermomyces lanuginosus. The use of ultrasound to assist the reactions revealed to be a key factor to obtain high conversion yields on both MTX conjugates. Transesterification reactions including long chain triacylglycerols were only successful when ultrasound was applied. In cyclodextrins esterification a higher number of MTX molecules was also linked to cyclodextrins when ultrasound was used. All the conjugates were characterized by MALDI-TOF and NMR spectroscopy.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Jennifer Noro also thanks to FCT – Fundação para a Ciência e a Tecnologia for funding her scholarship (SFRH/BD/121673/2016). This work has also received funding from the European Union Horizon 2020 research and innovation programme under grant agreement NMP-06-2015-683356 FOLSMART.info:eu-repo/semantics/publishedVersio
Clinical and Genetic Characterization of Portuguese Patients with Pseudohypoparathyroidism Type Ib
Patients with pseudohypoparathyroidism type Ib (PHP-Ib) present hypocalcemia and hyperphosphatemia, as a consequence of a resistance to PTH action, through its G-protein-coupled receptor, in the renal tubules. This resistance results from tissue-specific silencing of the G-protein alpha-subunit (G(s)α), due to imprinting disruption of its encoding locus--GNAS. In familial PHP-Ib, maternally inherited deletions at the STX16 gene are associated to a regional GNAS methylation defect. In sporadic PHP-Ib, broad methylation changes at GNAS arise from unknown genetic causes. In this study, we describe the clinical presentation of PHP-Ib in four Portuguese patients (two of whom were siblings), and provide further insight for the management of patients with this disease. The diagnosis of PHP-Ib was made after detection of GNAS imprinting defects in each of the cases. In the siblings, a regional GNAS methylation change resulted from a known 3.0 kb STX16 deletion. In the other two patients, the broad methylation defects at GNAS, which were absent in their relatives, resulted from genetic alterations that remain to be identified. We report the first clinical and genetic study of Portuguese patients with PHP-Ib. The genetic identification of a hereditary form of this rare disease allowed an early diagnosis, and may prevent hypocalcemia-related complications
Protein matrices for improved wound healing : elastase inhibition by a synthetic peptide model
The unique properties of silk fibroin were combined with keratin to develop new wound-dressing materials. Silk fibroin/keratin (SF/K) films were prepared to reduce high levels of elastase found on chronic wounds. This improved biological function was achieved by the incorporation of a small peptide synthesized based on the reactive-site loop of the Bowman−Birk Inhibitor (BBI) protein. In vitro degradation and release were evaluated using porcine pancreatic elastase (PPE) solution as a model of wound exudate. It was found that biological degradation and release rate are highly dependent on film composition. Furthermore, the level of PPE activity can be tuned by changing the film composition, thus showing an innovative way of controlling the elastase−antielastase imbalance found on chronic wounds.We would like to acknowledge FCT - Portuguese Foundation for Science and Technology for the scholarship concession; European project Lidwine, contract no. NMP2-CT-2006-026741, and Silvia Cappellozza from "Sezione Specializzata per la Bachicoltura" for the supply of silk cocoons
Prescribing-Assessment Tools for Long-Term Care Pharmacy Practice: Reaching Consensus through a Modified RAND/UCLA Appropriateness Method
Supplementary Materials - The following are available online at https://www.mdpi.com/article/10.3390/pharmacy9040194/s1, Table S1: Summary of the identified Prescribing-Assessment Tools.Medicines are the most used health technology in Long-Term Care. The prevalence of potentially inappropriate medicines amongst Long-Term Care patients is high. Pharmacists, assisted by prescribing-assessment tools, can play an important role in optimizing medication use at this level of care. Through a modified RAND/UCLA Appropriateness Method, 13 long-term care and hospital pharmacists assessed as ‘appropriate’, ‘uncertain’, or ‘inappropriate’ a collection of commonly used prescribing-assessment tools as to its suitability in assisting pharmacy practice in institutional long-term care settings. A qualitative analysis of written or transcribed comments of participants was pursued to identify relevant characteristics of prescribing-assessment tools and potential hinders in their use. From 24 different tools, pharmacists classified 9 as ‘appropriate’ for pharmacy practice targeted to long-term care patients, while 3 were classified as ‘inappropriate’. The tools feature most appreciated by study participants was the indication of alternatives to potentially inappropriate medication. Lack of time and/or pharmacists and limited access to clinical information seems to be the most relevant hinders for prescribing-assessment tools used in daily practice.info:eu-repo/semantics/publishedVersio
Protein micro- and nano-capsules for biomedical applications
Micro- and nano-scale systems have emerged as important tools for developing clinically useful drug delivery systems. In this tutorial review, we discuss the exploitation of biomacromolecules for this purpose, focusing on proteins, polypeptides, nucleic acids and polysaccharides and mixtures thereof as potential building blocks for novel drug delivery systems. We focus on the mechanisms of formation of micro- and nano-scale protein-based capsules and shells, as well as on the functionalization of such structures for use in targeted delivery of bioactive materials. We summarise existing methods for protein-based capsule synthesis and functionalization and highlight future challenges and opportunities for delivery strategies based on biomacromolecules.U.S. is grateful to Professor Aharon Gedanken, Chemistry Department, Bar-Ilan University, Israel, for his support and supervision during her PhD research work. G.J.L.B. is a Royal Society University Research Fellow at the Department of Chemistry, University of Cambridge and an Investigador FCT at the Instituto de Medicina Molecular, Lisboa. We thank Nuno Azoia assistance with the preparation of the figures. The authors thank the European Union Seventh Framework Programme (FP7/20072013) under grant agreement NMP4-LA-2009-228827 NANOFOL
Liposome formation with wool lipid extracts rich in ceramides
Internal wool lipids (IWLs) are rich in cholesterol, free fatty acids, cholesteryl sulfate, and, mainly, ceramides.
The repairing effect of these lipids structured as liposomes was demonstrated by reinforcing the
skin-barrier integrity and increasing the water-holding capacity when applied onto the skin. This work
was focused on the formation of liposomes with IWLs rich in ceramides, obtained at pilot plant level with
organic solvent extraction by using methanol and acetone. The lipid composition of the two extracts was
quantitatively analyzed. IWL extracts containing different amounts of sterol sulfate were used to form liposomes
at physiologic pH. Vesicle size distribution, polydispersity index, and zeta potential of all liposomes
were determined to characterize them and to study their stability. The results obtained showed that IWL
extract composition, which was different depending on the extraction methodologies used, greatly influences
the characteristics of the liposomes formed. Vesicular size and polydispersity index liposomes were
smaller when the extract composition contained a higher proportion of either free fatty acids or sterol
sulfate. Moreover, liposome stability was improved when some amount of sterol sulfate was added to the
composition of methanol and acetone extracts. This natural mixture with keratinaceous origin could have
a special interest for cosmetic or dermopharmaceutical companies.We acknowledge Mr. G. von Knorring for his expert technical assistance. We are also indebted to the DGICYT Program (PPQ 2002-94136-C02-01 and C02-02) for financial support
- …