Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Int J Mol Sci ; 24(2)2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36674489

RESUMEN

Chitosan is an interesting polymer to produce hydrogels suitable for the 3D printing of customized drug delivery systems. This study aimed at the achievement of chitosan-based scaffolds suitable for the incorporation of active components in the matrix or loaded into the pores. Several scaffolds were printed using different chitosan-based hydrogels. To understand which parameters would have a greater impact on printability, an optimization study was conducted. The scaffolds with the highest printability were obtained with a chitosan hydrogel at 2.5 wt%, a flow speed of 0.15 mm/s and a layer height of 0.41 mm. To improve the chitosan hydrogel printability, starch was added, and a design of experiments with three factors and two responses was carried out to find out the optimal starch supplementation. It was possible to conclude that the addition of starch (13 wt%) to the chitosan hydrogel improved the structural characteristics of the chitosan-based scaffolds. These scaffolds showed potential to be tested in the future as drug-delivery systems.


Asunto(s)
Quitosano , Drogas de Diseño , Andamios del Tejido/química , Quitosano/química , Hidrogeles/química , Sistemas de Liberación de Medicamentos , Impresión Tridimensional , Ingeniería de Tejidos
2.
Endocr Regul ; 56(2): 87-94, 2022 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-35489048

RESUMEN

Objective. Micromegaly describes a subgroup of patients with clinically evident acromegaly and elevated insulin-like growth factor I (IGF-I) with apparently normal basal growth hormone (bGH) and often a glucose-suppressed growth hormone (GH) of <1 ng/mL at diagnosis. It is controversial whether this condition is a distinct clinical entity or a classic acromegaly in early stages. The aim of the present article was to characterize the prevalence, clinical and biochemical characteristics, and therapeutic outcomes of micromegaly. Methods. A retrospective study of patients with an acromegaly followed ≥1 year at a tertiary center from 1995 to 2019. Patients without IGF-I or GH measurements at diagnosis were excluded. At diagnosis, bGH was considered normal if <2 ng/mL. Results. From 74 patients with acromegaly, 6 (8.1%) had normal bGH levels. There was no difference in the gender distribution, median diagnostic delay, and follow-up time between patients with normal bGH and elevated bGH. Patients with normal bGH were significantly older at time of the first acromegalic manifestation and diagnosis they had significantly lower nadir post-glucose GH and IGF-I levels, and tended to have a higher prevalence of obesity than patients with the elevated bGH. The frequency of acromegalic symptoms, signs, and other comorbidities than obesity was similar between groups. Five patients (83.3%) with normal bGH presented microadenomas. Post-operative remission and outcomes at last visit were comparable between patients with or without normal bGH. Conclusions. Normal bGH acromegaly is relatively uncommon in our patients. These patients showed differentiating characteristics from the classical acromegaly with elevated bGH. Further studies are needed to extend the knowledge about its clinical behavior, therapeutic outcomes, morbidity, and mortality.


Asunto(s)
Acromegalia , Hormona de Crecimiento Humana , Acromegalia/diagnóstico , Acromegalia/epidemiología , Acromegalia/terapia , Diagnóstico Tardío , Glucosa , Hormona del Crecimiento , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Obesidad , Estudios Retrospectivos , Resultado del Tratamiento
3.
Anal Bioanal Chem ; 413(16): 4311-4320, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34003328

RESUMEN

Biosurfactants have been investigated as potential alternatives for synthetic surfactants in several areas, for example, in environmental and pharmaceutical fields. In that regard, extensive research has been carried out with sophorolipids and rhamnolipids that also present various biological properties with therapeutic significance. These biosurfactants are obtained as complex mixtures of slightly different molecules, and thus when studying these microbial glycolipids, the ability to identify and purify the produced compounds is of extreme importance. This study aimed to develop improved methodologies for the identification, separation, and purification of sophorolipids and rhamnolipids. Therefore, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was modified to ensure faster characterization of both sophorolipids and rhamnolipids, enabling the identification and fragmentation pattern description of 10 and 13 congeners, respectively. The separation and purification of these biosurfactants was achieved with novel reversed-phase solid-phase extraction methods guaranteeing the isolation of different glycolipids, including those considered for their significant biological activity (e.g. antimicrobial, anticancer). It was possible to isolate sophorolipids and rhamnolipids with purity of 94% and 99%, respectively. The methods presented herein can be easily implemented and are expected to make purification of these biosurfactants easier, facilitating the study of their individual properties in further works.


Asunto(s)
Glucolípidos/análisis , Ácidos Oléicos/análisis , Tensoactivos/análisis , Cromatografía Líquida de Alta Presión , Glucolípidos/aislamiento & purificación , Ácidos Oléicos/aislamiento & purificación , Pseudomonas aeruginosa/química , Saccharomycetales/química , Extracción en Fase Sólida , Tensoactivos/aislamiento & purificación , Espectrometría de Masas en Tándem
4.
Int J Mol Sci ; 21(15)2020 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-32751908

RESUMEN

This work reports the versatility of polydopamine (PD) when applied as a particle coating in a composite of polylactide (PLA). Polydopamine was observed to increase the particle-matrix interface strength and facilitate the adsorption of drugs to the material surface. Here, barium sulfate radiopaque particles were functionalized with polydopamine and integrated into a polylactide matrix, leading to the formulation of a biodegradable and X-ray opaque material with enhanced mechanical properties. Polydopamine functionalized barium sulfate particles also facilitated the adsorption and release of the antibiotic levofloxacin. Analysis of the antibacterial capacity of these composites and the metabolic activity and proliferation of human dermal fibroblasts in vitro demonstrated that these materials are non-cytotoxic and can be 3D printed to formulate complex biocompatible materials for bone fixation devices.


Asunto(s)
Sulfato de Bario/química , Materiales Biocompatibles , Indoles/química , Poliésteres/química , Polímeros/química , Ingeniería de Tejidos , Andamios del Tejido , Antibacterianos/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Portadores de Fármacos/química , Fibroblastos , Humanos , Levofloxacino/farmacología , Fenómenos Mecánicos
5.
J Mater Sci Mater Med ; 27(7): 123, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27300006

RESUMEN

Several types of biodegradable materials have been investigated for the treatment of osteomyelitis. Calcium phosphate (CaP) ceramics are among the most performing materials due to their resemblance to human hard tissues in terms of mineralogical composition, and proven ability to adsorb and deliver a number of drugs. This research work was intended to study the suitability of modified CaP powders loaded with a fluoroquinolone as drug delivery systems for osteomyelitis treatment. Levofloxacin (LEV) was chosen due to the well-recognized anti-staphylococcal activity and adequate penetration into osteoarticular tissues. Substituted CaP powders (5 mol% Sr(2+) or 5 mol% Mg(2+)) were synthesised through aqueous precipitation. The obtained powders were characterised by X-ray diffraction, SEM and FTIR analysis. The X-ray diffraction patterns confirmed the presence of HA and ß-tricalcium phosphates (ß-TCP) phases in doped compositions, especially in the case of Mg-doped system. The fixation of LEV at the surface of the particles occurred only by physisorption. Both the in vitro microbiological susceptibility, against Staphylococcus spp, and biocompatibility of LEV-loaded CaP powders have not been compromised.


Asunto(s)
Fosfatos de Calcio/química , Levofloxacino/química , Magnesio/química , Estroncio/química , Animales , Antibacterianos/química , Materiales Biocompatibles/química , Biopolímeros/química , Línea Celular , Cromatografía Líquida de Alta Presión , Escherichia coli , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Osteomielitis/tratamiento farmacológico , Osteomielitis/prevención & control , Polvos/química , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus/metabolismo , Staphylococcus aureus , Staphylococcus epidermidis , Difracción de Rayos X
6.
Bioprocess Biosyst Eng ; 39(12): 1825-1837, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27538771

RESUMEN

Sophorolipids (SLs) were produced by Starmerella bombicola. The separation and purification of SLs are a complex process, since they are produced as a mixture of compounds with few structural differences. Solvent extraction is commonly used in downstream processing. In this work, an environmental friendly approach was developed for SLs recovery and purification, based on neutral polymeric sorbents, Amberlite XAD16NTM, XAD18TM, and XAD1600NTM. In batch microassays, key parameters of sorption/desorption process (e.g., contact time, temperature, sorbents, and SLs concentrations) were optimized for separation of acidic and lactonic SLs. Sorption equilibrium was reached after 2-3 h, for all the sorbents tested. Among them XAD1600NTM showed a higher sorption capacity (q max 230 mg g-1), a higher removal (≈100 %) of acidic and lactonic SLs [1 and 2.5 % (w/v)], and the best selectivity. Methanol, ethanol, and acetone were suitable for SLs elution. A selective desorption of SLs was attained with acetonitrile aqueous solutions (v/v): (1) 25 % led to 88.3 % of acidic SLs and (2) 55 % followed by methanol solution (100 %) led to 93.2 % of purified lactonic SLs. This achievement was particularly important regarding SLs potential therapeutic applications, since acidic and lactonic SLs show different biologic activities. In fact, acid SLs show higher virucidal and pro-inflammatory cytokine activity, while lactonic SLs show stronger spermicidal and anti-cancer activity.


Asunto(s)
Antineoplásicos , Medios de Cultivo/química , Lípidos , Saccharomycetales/crecimiento & desarrollo , Espermicidas , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Lípidos/biosíntesis , Lípidos/química , Lípidos/aislamiento & purificación , Espermicidas/química , Espermicidas/aislamiento & purificación
7.
Orbit ; 35(4): 175-80, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27192038

RESUMEN

Periorbital cellulitis is a relatively common ocular disease in the pediatric population. Early diagnosis of this disease with a prompt intervention is critical to avoid vision and life-threatening complications. In the last years, medical therapy has been expanding for the treatment of orbital cellulitis, instead of the standard surgical approach. The purpose of this study was to describe the outcome of treatment with intravenous antibiotic of periorbital cellulitis in children. A retrospective review of all children admitted with periorbital cellulitis in our hospital between January 2002 and July 2013 was conducted. Cases were divided in two subgroups, pre-septal and post-septal infection. The demographics, clinical findings, treatment and outcomes were analyzed. In total 110 children were included, 93 with pre-septal and 17 with post-septal cellulitis. The mean age was 3.5 years in children with pre-septal cellulitis and 5.5 years in those with post-septal cellulitis (p = 0.149). For both subgroups the most common predisposing factor was sinusitis. Intravenous antibiotic therapy was successful in all except one patient with an orbital abscess who required surgical intervention. In our study complete recovery was achieve in all (except for one) children with periorbital cellulitis treated with intravenous antibiotics only.


Asunto(s)
Antibacterianos/uso terapéutico , Celulitis Orbitaria/tratamiento farmacológico , Adolescente , Antibacterianos/administración & dosificación , Niño , Preescolar , Femenino , Humanos , Lactante , Infusiones Intravenosas , Tiempo de Internación/estadística & datos numéricos , Masculino , Celulitis Orbitaria/etiología , Estudios Retrospectivos , Factores de Riesgo
8.
J Mol Recognit ; 28(3): 155-65, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25647712

RESUMEN

Sophorolipids (SLs) are glycolipid biosurfactants, produced as a mixture of several compounds by some nonpathogenic yeast. In the current study, separation of individual SLs from mixtures with further evaluation of their surface properties and biologic activity on MDA-MB-321 breast cancer cell line were investigated. SLs were biosynthesized by Starmerella bombicola in a culture media supplemented with borage oil. A reverse-phase flash chromatography method with an automated system coupled with a prepacked cartridge was used to separate and purify the main SLs. Compositional analysis of SLs was performed by high-performance liquid chromatography with electrospray ionization mass spectrometry and tandem mass spectrometry. The following diacetylated lactonic SLs were isolated and purified: C18:0, C18:1, C18:2, and C18:3. The critical micelle concentration (CMC) and surface tension at CMC (γCMC ) of the purified SLs showed an increase with the number of double bonds. High cytotoxic effect against MDA-MB-231 cells was observed with C18:0 and C18:1 lactonic SLs. The cytotoxic effects of C18:3 lactonic SL on cancerous cells were for the first time studied. This cytotoxic effect was considerably higher than the promoted by acidic SLs; however, it induced a lower effect than the previously mentioned SLs, C18:0 and C18:1. To our knowledge, for the first time, C18:1 lactonic SL, in selected concentrations, proved to be able to inhibit MDA-MB-231 cell migration without compromising cell viability and to increase intracellular reactive oxygen species.


Asunto(s)
Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Glucolípidos/biosíntesis , Glucolípidos/farmacología , Saccharomycetales/fisiología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Cromatografía Liquida/métodos , Medios de Cultivo/química , Femenino , Humanos , Aceites de Plantas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem , Ácido gammalinolénico/farmacología
9.
Int Ophthalmol ; 35(2): 275-9, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25649259

RESUMEN

A 59-year-old man who complained of binocular vertical diplopia after an exploratory laparotomy, complicated by cardiorespiratory arrest during anesthetic induction, was found to have Collier's sign, anisocoria, complete paralysis of upward vertical gaze associated with convergence-retraction nystagmus on attempted upgaze and skew deviation with hypertropia in the left eye without ptosis, and an absent Bielschowsky sign. Magnetic resonance imaging of the brain showed a small lesion in the left paramedian midbrain compatible with microvascular ischemic sequelae. This patient was diagnosed with Parinaud's syndrome (dorsal midbrain syndrome) associated with a vertical strabismus from an unilateral vascular ischemic paramedian midbrain lesion.


Asunto(s)
Isquemia Encefálica/complicaciones , Diplopía/etiología , Trastornos de la Motilidad Ocular/etiología , Humanos , Masculino , Persona de Mediana Edad , Síndrome
10.
Rev Port Cardiol ; 2024 Jul 12.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-39004141

RESUMEN

INTRODUCTION AND OBJECTIVES: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in Portugal, thus it is important to identify individuals at risk. Patients with hypertension have an increased risk of adverse cardiovascular (CV) events. The role of LDL cholesterol (LDL-C) in atherosclerotic CVD is well-established. SCORE2, a new CV risk calculation tool, is used to predict the 10-year risk of fatal or non-fatal CVD. The aim of this study was to understand the impact of SCORE2 on CV risk assessment in a population with hypertension from a moderate risk country, compared to the previously used SCORE. METHODS: This observational cross-sectional study analyzed a population census of 3146 patients diagnosed with hypertension without complications (K86). After applying inclusion and exclusion criteria, 654 patients were included. Data from medical records were collected to calculate and compare SCORE and SCORE2 categories and LDL-C targets. RESULTS: Patients were classified into SCORE categories: 188 (28.75%) low, 448 (68.5%) moderate, 17 (2.6%) high and 1 (0.15%) very high risk. Using SCORE2, individuals in the SCORE low risk category were reclassified, requiring new targets: 149 individuals (80%) as low to moderate and 39 (20%) as high risk. These differences became more evident when considering SCORE moderate and high-risk categories, where 358 patients (77%) received a higher CV risk categorization, and therefore a lower LDL-C target. There was a significant increase in individuals failing to meet the target when using SCORE2, compared to SCORE (p<0.001). CONCLUSION: These findings support the importance of CV risk assessment using SCORE2 algorithm in patients with hypertension.

11.
Strabismus ; 32(2): 115-120, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38801053

RESUMEN

Results: The study cohort comprised five patients, each presenting with unilateral high axial myopia and classic clinical features of HES, including large angle esotropia, hypotropia, and restricted abduction and supraduction. All patients displayed evident superotemporal globe prolapse on MRI imaging, corresponding to the downward displacement of the LR muscle and medial shift of the SR muscle.Following the surgical procedure, all patients demonstrated significant improvements in both vertical and horizontal deviations, effectively addressing the primary clinical manifestations of HES.Conclusions: In the management of HES, several surgical approaches have been explored, yielding mixed results. Our study, employing the technique of partial muscle splitting and scleral fixation, offers a promising avenue for effectively addressing this challenging condition. By adapting the full loop myopexy technique originally proposed by Yokoyama et al. we achieved satisfactory ocular alignment in all five patients. Notably, this approach mitigates the risk of anterior segment ischemia by preserving the unsecured portions of the SR and LR muscles along with MR retroequatorial myopexy.These findings support the consideration of this surgical technique as a safe and effective option for managing HES, providing both cosmetic and functional improvements to afflicted individuals.


Asunto(s)
Imagen por Resonancia Magnética , Músculos Oculomotores , Procedimientos Quirúrgicos Oftalmológicos , Humanos , Músculos Oculomotores/cirugía , Músculos Oculomotores/fisiopatología , Femenino , Masculino , Procedimientos Quirúrgicos Oftalmológicos/métodos , Adulto , Persona de Mediana Edad , Resultado del Tratamiento , Esotropía/cirugía , Esotropía/fisiopatología , Movimientos Oculares/fisiología , Miopía Degenerativa/cirugía , Miopía Degenerativa/fisiopatología , Miopía Degenerativa/complicaciones
12.
Appl Microbiol Biotechnol ; 97(5): 1875-87, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23064480

RESUMEN

Microtiter plates were used as minireactors to study Starmerella bombicola growth and sophorolipid (SL) production. Compositional analysis of SL mixtures by liquid chromatography with electrospray ionization tandem mass spectrometry showed similar results on SLs produced using the laboratory scale (shake flask) and the microscale (24-well microtiter plates (MTP)) approach. MTP suitability on SL production was proven, being this approach, especially advantageous on SL screening. Several hydrophilic carbon sources, hydrophobic co-substrates and nitrogen sources were supplied to culture media, and their influence on SL production was evaluated. The selection of specific hydrophobic co-substrate and nitrogen sources influenced the ratio acidic/lactonic SLs. In fact, it was observed that the production of acidic C18:1 diacetylated hydroxy fatty acid SLs was favoured when culture media was supplied with avocado, argan, sweet almond and jojoba oil or when NaNO(3) was supplied instead of urea. This last case was observed after 144 h of cultivation. A new SL, lactonic C18:3 hydroxy fatty acid diacetylated SL, was detected when borage and onagra oils were used individually as co-substrates. Overall results indicated the potential of the selective production of different and new sophorolipids by Starmerella bombicola based on the selection of carbon and nitrogen sources to culture media.


Asunto(s)
Ascomicetos/crecimiento & desarrollo , Ascomicetos/metabolismo , Medios de Cultivo/química , Glucolípidos/metabolismo , Carbono/metabolismo , Cromatografía Liquida , Ensayos Analíticos de Alto Rendimiento/métodos , Nitrógeno/metabolismo , Aceites de Plantas/metabolismo , Espectrometría de Masas en Tándem
13.
Eur J Case Rep Intern Med ; 10(6): 003905, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37305007

RESUMEN

We report a case of a 19-year-old young male presenting with thyrotoxicosis with inappropriately elevated TSH. Magnetic resonance imaging revealed a pituitary adenoma (8.2 × 9.7 mm), TRH stimulation test showed abnormal blunted TSH response, and serum glycoprotein hormone alpha-sub-unit was elevated. He had no family history of thyroid disease and TRß genetic testing excluded resistance to thyroid hormone action. The diagnosis of thyrotropin-secreting pituitary adenoma (TSHoma) was presumed and long-acting somatostatin analogue was promptly initiated. After two months of octreotide treatment, serum TSH and FT3 returned to within normal ranges. Tumour resection by transsphenoidal surgery was performed and, ten days after surgery, clinical hypothyroidism was achieved, despite detectable TSH levels (TSH 1.02 µU/ml[RR 0.27-4.2]). Although the patient remained euthyroid for the following three years, there was a gradual biochemical elevation in the levels of TSH, FT4, and FT3 over time, reaching serum values above the normal limit in the third year after surgery. Imaging did not show neoplasm recurrence at this point. After two years, the patient presented with clinical manifestations of re-onset thyrotoxicosis, with MRI revealing a T2 hypersignal oval area compatible with a pituitary adenoma. Adenectomy was performed. Histopathological and immunohistochemical analyses revealed a pituitary adenoma with transcription factor PIT1 expression and positivity for TSH and PRL. TSHoma treatment may not be always effective in the first therapeutic approach and recurrences are a possibility, making follow-up essential. The present case highlights the heterogeneity of post-treatment cure criteria and their limitations. LEARNING POINTS: Thyrotropin-secreting pituitary adenomas are rare benign tumours. Proper diagnosis can be challenging, requiring TSH autonomous production and differentiation from resistance to thyroid hormone action (RTH).Undetectable TSH levels one week after surgery and/or positive T3 suppression test or no response to TRH stimulation test seem to be the criteria with the best prognostic value post-treatment.Close clinical, biochemical and imaging follow-up is crucial to detect TSHoma recurrence.

14.
Membranes (Basel) ; 13(1)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36676888

RESUMEN

Glycolipid biosurfactants are the most prominent group of microbial biosurfactants, comprising rhamnolipids, sophorolipids and mannosylerythritol lipids (MELs). Usually, large amounts of hydrophobic substrates (e.g., vegetable oils) are used to achieve high titers (~200 g/L) of a crude product of low purity at values limited to 50-60%, contaminated with unconsumed triacylglycerol and residual free fatty acids and monoacylglycerides. The methods reported for the removal of these contaminants use a mixture of organic solvents, compromising solvent recyclability and increasing final process costs. This study reports, for the first time, an innovative downstream method for MELs, in which 90% of the triacylglycerols are separated from the crude MEL mixture in a first stage and the other lipid derivatives (free fatty acids, mono- and diacylglycerols) are removed by organic solvent nanofiltration (OSN). Three commercially available membranes (GMT-oNF-2, PuraMEm-600 and DuramMem-500) and several homemade membranes, casted from 22, 24 or 26% (w/v) polybenzimidazole (PBI) solutions, were assessed for crude MELs purification by diafiltration. A final purity of 87-90% in the MELs was obtained by filtering two diavolumes of methanol or ethyl acetate solutions through a PBI 26% membrane, resulting in MELs losses of 14.7 ± 6.1% and 15.3 ± 2.2%, respectively. Higher biosurfactant purities can be archived using the PBI 26% membrane at higher DV, but at the cost of higher product losses. Namely, in MeOH, the use of 6 DV leads to losses of 32% for MELs and 18% for sophorolipids. To obtain MELs at reagent grade with purities equal or higher than 97%, a two-sequential cascade filtration approach was implemented using the commercial membrane, GMT-oNF. In such a process, MELs with 98% purity was obtained at the cost of 11.6% MELs losses. Finally, decoloration, important in some applications, was successfully assessed using activated carbon. Overall, this study reports a unique solution for microbial biosurfactants production with minimal product losses, enabling solvent recycling and potentially reducing costs.

15.
Colloids Surf B Biointerfaces ; 230: 113486, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37572399

RESUMEN

Infections associated with the surfaces of medical devices represent a critical problem due to biofilm formation and the growing resistance towards antibacterial drugs. This is particularly relevant in commonly used invasive devices such as silicone-based ones where a demand for alternative antibiofilm surfaces is increasing. In this work, an antimicrobial chitosan-biosurfactant hydrogel mesh was produced by 3D-printing. The 3D structure was designed to coat polydimethylsiloxane-based medical devices for infection prevention. Additionally, the porous 3D structure allows the incorporation of customized bioactive components. For this purpose, two biosurfactants (surfactin and sophorolipids) were biosynthesized and tested for their antimicrobial activity. In addition, the printing of surfactant-chitosan-based coatings was optimized, and the resulting 3D structures were characterized (i.e., wettability, FTIR-ATR, antimicrobial activity, and biocompatibility). Compared with surfactin, the results showed a better yield and higher antibacterial activity against Gram-positive bacteria for sophorolipids (SLs). Thus, SLs were used to produce chitosan-based 3D-printed coatings. Overall, the SLs-impregnated coatings showed the best antibacterial activity against Staphylococcus aureus planktonic bacteria (61 % of growth inhibition) and antibiofilm activity (2 log units reduction) when compared to control. Furthermore, concerning biocompatibility, the coatings were cytocompatible towards human dermal fibroblasts. Finally, the coating presented a mesh suitable to be filled with a model bioactive compound (i.e., hyaluronic acid), paving the way to be used for customized therapeutics.


Asunto(s)
Antiinfecciosos , Quitosano , Humanos , Siliconas/química , Quitosano/farmacología , Quitosano/química , Antibacterianos/farmacología , Antibacterianos/química , Staphylococcus aureus , Impresión Tridimensional , Materiales Biocompatibles Revestidos/química , Biopelículas
16.
Int J Pharm ; 631: 122470, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36516927

RESUMEN

The high recurrence rate of common denture stomatitis after antifungal treatment is still concerning. This condition is caused by low patient compliance and incomplete local elimination of the main etiological factor - Candida albicans, often associated with other microorganisms, such as Streptococcus species. Impregnating denture materials with antimicrobials for local delivery is a strategy that can overcome the side effects and improve the efficacy of conventional treatments (topical and/or systemic). In this work, we describe the development of three hard autopolymerizing reline acrylic resins (Kooliner, Ufi Gel Hard, and Probase Cold) loaded with different percentages of chlorhexidine (CHX). The novel formulations were characterized based on their antimicrobial activity, mechanical, morphological and surface properties, in-vitro drug release profiles, and cytotoxicity. The addition of CHX in all resins did not change their chemical and mechanical structure. Among all the tested formulations, Probase Cold loaded with 5 wt% CHX showed the most promising results in terms of antimicrobial activity and lack of serious detrimental mechanical, morphological, surface, and biological properties.


Asunto(s)
Antiinfecciosos , Clorhexidina , Humanos , Ensayo de Materiales , Resinas Acrílicas/química
17.
Echo Res Pract ; 10(1): 7, 2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37076874

RESUMEN

Pregnancy is a dynamic process associated with profound hormonally mediated haemodynamic changes which result in structural and functional adaptations in the cardiovascular system. An understanding of the myocardial adaptations is important for echocardiographers and clinicians undertaking or interpreting echocardiograms on pregnant and post-partum women. This guideline, on behalf of the British Society of Echocardiography and United Kingdom Maternal Cardiology Society, reviews the expected echocardiographic findings in normal pregnancy and in different cardiac disease states, as well as echocardiographic signs of decompensation. It aims to lay out a structure for echocardiographic scanning and surveillance during and after pregnancy as well as suggesting practical advice on scanning pregnant women.

18.
J Mol Recognit ; 25(11): 630-40, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23108623

RESUMEN

Rhodotorula bogoriensis is known as the producer of longer chain acidic sophorolipids (SLs) with a unique hydroxylation position where the sophorose unit is linked to the 13-hydroxydocosanoic acid. The influence of initial inoculum concentration, hydrophilic and hydrophobic carbon, and nitrogen sources on R. bogoriensis growth and SL production was evaluated to obtain a selective SL production. Experiments took place in microtiter plates, used as minireactors, after the verification of its suitability compared with shake flasks. The common structure of SLs is the 13-[2'-O-ß-d-glucopyranosyl-ß-d-glucopyranosyloxy]-docosanoic acid SL. The analysis of the fermentation media using high-performance liquid chromatography with evaporative light scattering detector showed the production of four main SLs, respectively, in the following forms: (i) deacetylated (peak A) (C22:0 SL), (ii) 6″monoacetylated (peak B) (C22:0-6″Ac SL), (iii) 6'monoacetylated (peak C) (C22:0-6'Ac SL), and (iv) 6',6″ diacetylated (peak D) (C22:0-6',6″Ac SL). The identification of compounds in SL mixtures was performed by liquid chromatography with electrospray ionization mass spectrometry analysis, and no differences were observed. Besides the four compounds detected using high-performance liquid chromatography with evaporative light scattering detector chromatograms, three other SLs was identified, corresponding to mono- and diacetylated C24:0 hydroxy fatty acid SLs. To our knowledge, this work presents for the first time the production and identification of C24:0 SLs. A longer hydrophobic tail on SLs had an important role in the improvement of surface active properties. The selection of a specific time for fermentation end and the use of different carbon (e.g. glucose, fructose, mannose, lactose, galactose, xylose) and nitrogen (e.g. peptone, (NH(4))(2)SO(4) and NaNO(3)) sources led to a selective production of de-, mono-, and diacetylated SLs by R. bogoriensis.


Asunto(s)
Carbono/metabolismo , Ácidos Grasos/química , Glucanos/química , Glucolípidos/biosíntesis , Nitrógeno/metabolismo , Rhodotorula/metabolismo , Cromatografía Líquida de Alta Presión , Medios de Cultivo , Ácidos Grasos/metabolismo , Fermentación , Glucanos/metabolismo , Glucolípidos/química , Glucolípidos/aislamiento & purificación , Espectrometría de Masa por Ionización de Electrospray
19.
Anesth Analg ; 114(1): 179-85, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22025490

RESUMEN

BACKGROUND: The infusion of local anesthetic in the surgical wound is helpful in the multimodal management of postoperative pain. We hypothesized that local anesthetic wound infusion after cesarean delivery would provide better pain control than epidural morphine analgesia. METHODS: Healthy, term women scheduled for elective cesarean delivery were included in this assessor-blinded, randomized study. Patients were randomly assigned to receive analgesia through a multiorifice wound catheter placed below the fascia and connected to a 5 mL/h ropivacaine 2 mg/mL infusion or an epidural bolus of morphine 2 mg every 12 hours. Both analgesic regimens were continued for 48 hours. The primary outcome was pain at rest at 24 hours postoperatively using the verbal rating score for pain (0-10 scale). Pain intensity, rescue analgesia consumption, and side effects were assessed at 2, 6, 24, and 48 hours after cesarean delivery by an observer blinded to group allocation. Three months after discharge, patient satisfaction, residual pain, and surgical wound complications were assessed. RESULTS: Fifty-eight women participated in the study. At 24 hours, the median rest verbal rating score for pain was 0 (interquartile range: 0-0) in the continuous infusion group and 3 in the epidural morphine group (interquartile range: 2-3; 95% confidence interval of difference: 1-3 units; P < 0.001). The median scores of the 2-, 6-, and 48-hour pain assessments at rest were also lower in the continuous wound infusion group than in the epidural morphine group, and at 2, 6, and 24 hours with movement (P < 0.001). The incidence of nausea, vomiting, pruritus, and urinary retention was significantly lower in the wound infusion group and time to recovery of bowel function was shorter. During the 48-hour follow-up evaluation, the median number of nurse visits attributed exclusively to the analgesic regimen was 1 (interquartile range: 1-2) in the continuous wound infusion group and 8 (interquartile range: 7-10) in the epidural morphine group (95% confidence interval of difference: 6-8 visits; P < 0.001). CONCLUSIONS: Continuous wound infusion with ropivacaine for 48 hours after cesarean delivery was associated with better analgesia, a lower incidence of side effects, less need for nursing care, and shorter duration of stay compared with epidural morphine analgesia.


Asunto(s)
Amidas/administración & dosificación , Analgesia Epidural , Analgesia Obstétrica/métodos , Analgésicos Opioides/administración & dosificación , Anestésicos Locales/administración & dosificación , Cesárea/efectos adversos , Morfina/administración & dosificación , Dolor Postoperatorio/prevención & control , Adolescente , Adulto , Amidas/efectos adversos , Analgesia Epidural/efectos adversos , Analgesia Obstétrica/efectos adversos , Analgésicos Opioides/efectos adversos , Anestésicos Locales/efectos adversos , Esquema de Medicación , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Tiempo de Internación , Persona de Mediana Edad , Morfina/efectos adversos , Dimensión del Dolor , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/etiología , Satisfacción del Paciente , Portugal , Embarazo , Ropivacaína , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
20.
Polymers (Basel) ; 14(22)2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36433095

RESUMEN

Packaging plays an important role in food quality and safety, especially regarding waste and spoilage reduction. The main drawback is that the packaging industry is among the ones that is highly dependent on plastic usage. New alternatives to conventional plastic packaging such as biopolymers-based type are mandatory. Examples are cellulose films and its derivatives. These are among the most used options in the food packaging due to their unique characteristics, such as biocompatibility, environmental sustainability, low price, mechanical properties, and biodegradability. Emerging concepts such as active and intelligent packaging provides new solutions for an extending shelf-life, and it fights some limitations of cellulose films and improves the properties of the packaging. This article reviews the available cellulose polymers and derivatives that are used as sustainable alternatives for food packaging regarding their properties, characteristics, and functionalization towards active properties enhancement. In this way, several types of films that are prepared with cellulose and their derivatives, incorporating antimicrobial and antioxidant compounds, are herein described, and discussed.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA