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1.
BMC Med Inform Decis Mak ; 24(1): 255, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39285367

RESUMEN

BACKGROUND: The aim is to develop and deploy an automated clinical alert system to enhance patient care and streamline healthcare operations. Structured and unstructured data from multiple sources are used to generate near real-time alerts for specific clinical scenarios, with an additional goal to improve clinical decision-making through accuracy and reliability. METHODS: The automated clinical alert system, named Smart Watchers, was developed using Apache NiFi and Python scripts to create flexible data processing pipelines and customisable clinical alerts. A comparative analysis between Smart Watchers and the legacy Elastic Watchers was conducted to evaluate performance metrics such as accuracy, reliability, and scalability. The evaluation involved measuring the time taken for manual data extraction through the electronic patient record (EPR) front-end and comparing it with the automated data extraction process using Smart Watchers. RESULTS: Deployment of Smart Watchers showcased a consistent time savings between 90% to 98.67% compared to manual data extraction through the EPR front-end. The results demonstrate the efficiency of Smart Watchers in automating data extraction and alert generation, significantly reducing the time required for these tasks when compared to manual methods in a scalable manner. CONCLUSIONS: The research underscores the utility of employing an automated clinical alert system, and its portability facilitated its use across multiple clinical settings. The successful implementation and positive impact of the system lay a foundation for future technological innovations in this rapidly evolving field.


Asunto(s)
Registros Electrónicos de Salud , Humanos , Registros Electrónicos de Salud/normas , Almacenamiento y Recuperación de la Información/métodos
2.
Eur Biophys J ; 52(4-5): 333-342, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37414903

RESUMEN

This study establishes the existence of substantial agreement between published results from traditional boundary spreading measurements (including synthetic boundary measurements in the analytical ultracenrifuge) on two globular proteins (bovine serum albumin, ovalbumin) and the concentration dependence of diffusion coefficient predicted for experiments conducted under the operative thermodynamic constraints of constant temperature and solvent chemical potential. Although slight negative concentration dependence of the translational diffusion coefficient is the experimentally observed as well as theoretically predicted, the extent of the concentration dependence is within the limits of experimental uncertainty inherent in diffusion coefficient measurement. Attention is then directed toward the ionic strength dependence of the concentration dependence coefficient ([Formula: see text]) describing diffusion coefficients obtained by dynamic light scattering, where, in principle, the operative thermodynamic constraints of constant temperature and pressure preclude consideration of results in terms of single-solute theory. Nevertheless, good agreement between predicted and published experimental ionic strength dependencies of [Formula: see text] for lysozyme and an immunoglobulin is observed by a minor adaptation of the theoretical treatment to accommodate the fact that thermodynamic activity is monitored on the molal concentration scale because of the constraint of constant pressure that pertains in dynamic light scattering experiments.


Asunto(s)
Racionalización , Albúmina Sérica Bovina , Dispersión Dinámica de Luz , Estudios Retrospectivos , Concentración Osmolar , Difusión , Dispersión de Radiación
3.
Eur Biophys J ; 52(4-5): 427-438, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37055656

RESUMEN

A recent investigation was aimed at obtaining structural information on a highly extended protein via SEC-MALS-SAXS. Significantly broadened elution peaks were observed, reminiscent of a phenomenon known as viscous fingering. This phenomenon is usually observed above 50 mg/mL for proteins like bovine serum albumin (BSA). Interestingly, the highly extended protein (Brpt5.5) showed viscous fingering at concentrations lower than 5 mg/mL. The current study explores this and other non-ideal behavior, emphasizing the presence of these effects at relatively low concentrations for extended proteins. BSA, Brpt5.5, and a truncated form of Brpt5.5 referred to as Brpt1.5 are studied systematically using size-exclusion chromatography (SEC), sedimentation velocity analytical ultracentrifugation (AUC), and viscosity. The viscous fingering effect is quantified using two approaches and is found to correlate well with the intrinsic viscosity of the proteins-Brpt5.5 exhibits the most severe effect and is the most extended protein tested in the study. By AUC, the hydrodynamic non-ideality was measured for each protein via global analysis of a concentration series. Compared to BSA, both Brpt1.5 and Brpt5.5 showed significant non-ideality that could be easily visualized at concentrations at or below 5 mg/mL and 1 mg/mL, respectively. A variety of relationships were examined for their ability to differentiate the proteins by shape using information from AUC and/or viscosity. Furthermore, these relationships were also tested in the context of hydrodynamic modeling. The importance of considering non-ideality when investigating the structure of extended macromolecules is discussed.


Asunto(s)
Hidrodinámica , Albúmina Sérica Bovina , Dispersión del Ángulo Pequeño , Difracción de Rayos X , Viscosidad , Sustancias Macromoleculares
4.
Eur Biophys J ; 52(4-5): 343-352, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37460663

RESUMEN

This investigation examines the source of the disparity between experimental values of the light scattering second virial coefficient [Formula: see text] (mL.mol/g2) for proteins and those predicted on the statistical mechanical basis of excluded volume. A much better theoretical description of published results for lysozyme is obtained by considering the experimental parameters to monitor the difference between the thermodynamic excluded volume term and its hydrodynamic counterpart. This involves a combination of parameters quantifying concentration dependence of the translational diffusion coefficient obtained from dynamic light scattering measurements. That finding is shown to account for observations of a strong correlation between [Formula: see text] (mL/g), where M2 is the molar mass (molecular weight) of the macromolecule and the diffusion concentration parameter [Formula: see text] (mL/g). On the grounds that [Formula: see text] is regarded as a hydrodynamic parameter, the same status should be accorded the light scattering second virial coefficient rather than its current incorrect thermodynamic designation as [Formula: see text] (mL.mol/g2), or just B, the osmotic second virial coefficient for protein self-interaction.


Asunto(s)
Hidrodinámica , Proteínas , Dispersión Dinámica de Luz , Sustancias Macromoleculares , Difusión , Soluciones , Luz , Dispersión de Radiación
5.
Eur Biophys J ; 52(4-5): 439-443, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37195494

RESUMEN

The solution properties of two different glycoforms of IgG1 (IgG1Cri and IgG1Wid) are compared using primarily sedimentation equilibrium analysis with two complementary analysis routines: SEDFIT-MSTAR and MULTISIG. IgGCri bears diantennary complex-type glycans on its Fc domain that are fully core fucosylated and partially sialylated, whilst on IgGWid, they are non-fucosylated, partially galactosylated and non-sialylated. IgGWid is also Fab glycosylated. Despite these differences, SEDFIT-MSTAR analysis shows similar weight average molar masses Mw of ~ (150 ± 5) kDa for IgGCri and ~ (154 ± 5) kDa for IgGWid and both glycoforms show evidence of the presence of a small fraction of dimer confirmed by MULTISIG analysis and also by sedimentation coefficient distributions from supportive sedimentation velocity measurements. The closeness of the sedimentation equilibrium behaviour and sedimentation coefficient distributions with a main peak sedimentation coefficient of ~ 6.4S for both glycoforms at different concentrations suggest that the different glycosylation profiles do not significantly impact on molar mass (molecular weight) nor conformation in solution.


Asunto(s)
Inmunoglobulina G , Polisacáridos , Glicosilación , Inmunoglobulina G/metabolismo , Fenómenos Físicos
6.
Eur Biophys J ; 49(8): 799-808, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33185715

RESUMEN

Aroma compounds are diverse low molecular weight organic molecules responsible for the flavour of food, medicines or cosmetics. Natural and artificial aroma compounds are manufactured and used by the industry to enhance the flavour and fragrance of products. While the low concentrations of aroma compounds present in food may leave no effect on the structural integrity of the mucosa, the effect of concentrated aroma volatiles is not well understood. At high concentrations, like those found in some flavoured products such as e-cigarettes, some aroma compounds are suggested to elicit a certain degree of change in the mucin glycoprotein network, depending on their functional group. These effects are particularly associated with carbonyl compounds such as aldehydes and ketones, but also phenols which may interact with mucin and other glycoproteins through other interaction mechanisms. This study demonstrates the formation of such interactions in vitro through the use of molecular hydrodynamics. Sedimentation velocity studies reveal that the strength of the carbonyl compound interaction is influenced by compound hydrophobicity, in which the more reactive short chain compounds show the largest increase in mucin-aroma sedimentation coefficients. By contrast, the presence of groups that increases the steric hindrance of the carbonyl group, such as ketones, produced a milder effect. The interaction effects were further demonstrated for hexanal using size exclusion chromatography light scattering (SEC-MALS) and intrinsic viscosity. In addition, phenolic aroma compounds were identified to reduce the sedimentation coefficient of mucin, which is consistent with interactions in the non-glycosylated mucin region.


Asunto(s)
Hidrocarburos Aromáticos/farmacología , Hidrodinámica , Mucinas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas/efectos de los fármacos , Mucinas/química , Fenoles/farmacología
7.
Eur Biophys J ; 47(7): 809-813, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30159596

RESUMEN

In establishing the sources of data variability within sedimentation velocity analysis in the analytical ultracentrifuge and their relative importance, recent studies have demonstrated that alignment of the sample cells to the centre of rotation is the most significant contributing factor to overall variability, particularly for the characterisation of low levels of protein aggregation. Accurate mechanical and optical alignment tools have been recently designed. In this study, we (1) confirm the effect of misalignment observed by others on the estimated amounts of bovine serum albumin (BSA) monomer and dimer, and the sedimentation coefficient value for the BSA dimer; and (2) demonstrate the high performance of a mechanical alignment tool and the usefulness of a simple and complementary enhanced manual alignment protocol which should be useful for situations where these tools are not available.


Asunto(s)
Fenómenos Mecánicos , Fenómenos Ópticos , Ultracentrifugación/métodos , Animales , Bovinos , Multimerización de Proteína , Estructura Cuaternaria de Proteína , Albúmina Sérica Bovina/análisis , Albúmina Sérica Bovina/química
8.
Sci Rep ; 13(1): 11367, 2023 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-37443326

RESUMEN

Glycopeptide antibiotics are regularly used in ophthalmology to treat infections of Gram-positive bacteria. Aggregative interactions of antibiotics with mucins however can lead to long exposure and increases the risk of resistant species. This study focuses on the evaluation of potential interactions of the last line of defence glycopeptide antibiotic teicoplanin with an ocular mucin model using precision matrix free hydrodynamic and microscopic techniques: sedimentation velocity in the analytical ultracentrifuge (SV-AUC), dynamic light scattering (DLS) and atomic force microscopy (AFM). For the mixtures of teicoplanin at higher doses (1.25 mg/mL and 12.5 mg/mL), it was shown to interact and aggregate with bovine submaxillary mucin (BSM) in the distributions of both sedimentation coefficients by SV-AUC and hydrodynamic radii by DLS. The presence of aggregates was confirmed by AFM for higher concentrations. We suggest that teicoplanin eye drop formulations should be delivered at concentrations of < 1.25 mg/mL to avoid potentially harmful aggregations.


Asunto(s)
Hidrodinámica , Teicoplanina , Animales , Bovinos , Mucinas , Antibacterianos/farmacología , Glicopéptidos
9.
Sci Rep ; 13(1): 1969, 2023 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-36737502

RESUMEN

The natural glycopeptide antibiotic teicoplanin is used for the treatment of serious Gram-positive related bacterial infections and can be administered intravenously, intramuscularly, topically (ocular infections), or orally. It has also been considered for targeting viral infection by SARS-CoV-2. The hydrodynamic properties of teicoplanin A2 (M1 = 1880 g/mol) were examined in phosphate chloride buffer (pH 6.8, I = 0.10 M) using sedimentation velocity and sedimentation equilibrium in the analytical ultracentrifuge together with capillary (rolling ball) viscometry. In the concentration range, 0-10 mg/mL teicoplanin A2 was found to self-associate plateauing > 1 mg/mL to give a molar mass of (35,400 ± 1000) g/mol corresponding to ~ (19 ± 1) mers, with a sedimentation coefficient s20, w = ~ 4.65 S. The intrinsic viscosity [[Formula: see text]] was found to be (3.2 ± 0.1) mL/g: both this, the value for s20,w and the hydrodynamic radius from dynamic light scattering are consistent with a globular macromolecular assembly, with a swelling ratio through dynamic hydration processes of ~ 2.


Asunto(s)
COVID-19 , Teicoplanina , Humanos , Hidrodinámica , SARS-CoV-2 , Antibacterianos , Glicopéptidos
10.
Food Chem ; 388: 133013, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-35483284

RESUMEN

This study aims to understand possible effects of flavour compounds on the structure and conformation of endogenous proteins. Using methyl anthranilate (a grape flavour compound added to drinks, confectionery, and vape-liquids) and bovine serum albumin (BSA, a model serum protein) we designed experimental investigations using analytical ultracentrifugation, size exclusion chromatography small angle X-ray scattering, and fluorescence spectroscopy to reveal that methyl anthranilate spontaneously binds to BSA (ΔG°, ca. -21 KJ mol-1) which induces a conformational compactness (ca. 10 %) in the monomer structure. Complementary molecular modelling and dynamics simulations suggested the binding occurs at Sudlow II of BSA via establishment of hydrogen bonds with arginine409, lysine413 and serine488 leading to an increased conformational order in domains IA, IIB and IIIB. This work aims to set the foundation for future research on flavour-protein interactions and offer new sets of opportunities for understanding the effects of small compounds on protein structure.


Asunto(s)
Albúmina Sérica Bovina , ortoaminobenzoatos , Dicroismo Circular , Conformación Molecular , Unión Proteica , Conformación Proteica , Albúmina Sérica Bovina/química , Espectrometría de Fluorescencia , Termodinámica
11.
Biophys Rev ; 13(2): 273-288, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33936319

RESUMEN

This retrospective investigation has established that the early theoretical attempts to directly incorporate the consequences of radial dilution into expressions for variation of the sedimentation coefficient as a function of the loading concentration in sedimentation velocity experiments require concentration distributions exhibiting far greater precision than that achieved by the optical systems of past and current analytical ultracentrifuges. In terms of current methods of sedimentation coefficient measurement, until such improvement is made, the simplest procedure for quantifying linear s-c dependence (or linear concentration dependence of 1/s) for dilute systems therefore entails consideration of the sedimentation coefficient obtained by standard c(s), g*(s) or G(s) analysis) as an average parameter ( s ¯ ) that pertains to the corresponding mean plateau concentration (following radial dilution) ( c ¯ ) over the range of sedimentation velocity distributions used for the determination of s ¯ . The relation of this with current descriptions of the concentration dependence of the sedimentation and translational diffusion coefficients is considered, together with a suggestion for the necessary improvement in the optical system.

12.
NPJ Digit Med ; 4(1): 35, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33627748

RESUMEN

Analyses of search engine and social media feeds have been attempted for infectious disease outbreaks, but have been found to be susceptible to artefactual distortions from health scares or keyword spamming in social media or the public internet. We describe an approach using real-time aggregation of keywords and phrases of freetext from real-time clinician-generated documentation in electronic health records to produce a customisable real-time viral pneumonia signal providing up to 4 days warning for secondary care capacity planning. This low-cost approach is open-source, is locally customisable, is not dependent on any specific electronic health record system and can provide an ensemble of signals if deployed at multiple organisational scales.

13.
Sci Rep ; 11(1): 1737, 2021 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-33462295

RESUMEN

This study concerns glulisine, a rapid-acting insulin analogue that plays a fundamental role in diabetes management. We have applied a combination of methods namely X-ray crystallography, and biophysical characterisation to provide a detailed insight into the structure and function of glulisine. X-ray data provided structural information to a resolution of 1.26 Å. Crystals belonged to the H3 space group with hexagonal (centred trigonal) cell dimensions a = b = 82.44 and c = 33.65 Å with two molecules in the asymmetric unit. A unique position of D21Glu, not present in other fast-acting analogues, pointing inwards rather than to the outside surface was observed. This reduces interactions with neighbouring molecules thereby increasing preference of the dimer form. Sedimentation velocity/equilibrium studies revealed a trinary system of dimers and hexamers/dihexamers in dynamic equilibrium. This new information may lead to better understanding of the pharmacokinetic and pharmacodynamic behaviour of glulisine which might aid in improving formulation regarding its fast-acting role and reducing side effects of this drug.


Asunto(s)
Hipoglucemiantes/química , Insulina/análogos & derivados , Fenómenos Biofísicos , Cristalografía por Rayos X/métodos , Humanos , Hipoglucemiantes/análisis , Insulina/análisis , Insulina/química , Multimerización de Proteína , Elementos Estructurales de las Proteínas , Relación Estructura-Actividad
14.
Sci Rep ; 10(1): 20855, 2020 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-33257785

RESUMEN

Consumer sensory evaluation, aroma release analysis and biophysical protein analysis were used to investigate the effect of ethanol on the release and perception of flavour in beer (lager and stout) at different ethanol levels (0 and 5% ABV). Consumer study results showed no significant differences in orthonasal perception, yet retronasal results showed that 0% lager was perceived as maltier with reduced fruitiness, sweetness, fullness/body and alcohol warming sensation (p < 0.05). Whilst ethanol alone decreases the aroma release regardless of LogP, the presence of α-amylase selectively reduces the headspace concentration of hydrophobic compounds. It was found that ethanol has a subtle inhibitory effect on the binding of hydrophobic compounds to α-amylase, thereby increasing their headspace concentration in the 5% ABV as compared to the 0% beers. This synergistic ethanol * saliva effect is attributed to the changes in the conformation of α-amylase due to ethanol-induced denaturation. It is hypothesised that the partially unfolded protein structures have a lower number of hydrophobic pockets, leading to a lower capacity to entrap hydrophobic aroma compounds. This supports the hypothesis that ethanol * saliva interactions directly impact the sensory and flavour properties of beer, which would provide a basis for further investigations in reformulation of 0% ABV drinks.

15.
NPJ Sci Food ; 4: 15, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33083547

RESUMEN

Food flavour ingredients are required by law to obtain prior approval from regulatory bodies, such as the U.S. Food and Drug Administration (FDA) or the European Food Safety Authority (EFSA) in terms of toxicological data and intended use levels. However, there are no regulations for labelling the type and concentration of flavour additives on the product, primarily due to their low concentration in food and generally recognised as safe (GRAS) status determined by the flavour and extract manufacturers' association (FEMA). Their status for use in e-cigarettes and other vaping products challenges these fundamental assumptions, because their concentration can be over ten-thousand times higher than in food, and the method of administration is through inhalation, which is currently not evaluated by the FEMA expert panel. This work provides a review of some common flavour ingredients used in food and vaping products, their product concentrations, inhalation toxicity and aroma interactions reported with different biological substrates. We have identified several studies, which suggest that the high concentrations of flavour through inhalation may pose a serious health threat, especially in terms of their cytotoxicity. As a result of the wide range of possible protein-aroma interactions reported in our diet and metabolism, including links to several non-communicable diseases, we suggest that it is instrumental to update current flavour- labelling regulations, and support new strategies of understanding the effects of flavour uptake on the digestive and respiratory systems, in order to prevent the onset of future non-communicable diseases.

16.
Polymers (Basel) ; 12(10)2020 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-33023220

RESUMEN

Hyaluronic acid (HA) has been commonly used in eyedrop formulations due to its viscous lubricating properties even at low concentration, acting as a supplement for ocular mucin (principally MUC5AC) which diminishes with aging in a condition known as Keratoconjunctivitis sicca or "dry eye". A difficulty has been its short residence time on ocular surfaces due to ocular clearance mechanisms which remove the polysaccharide almost immediately. To prolong its retention time, tamarind seed gum polysaccharide (TSP) is mixed as a helper biopolymer with HA. Here we look at the hydrodynamic characteristics of HA and TSP (weight average molar mass Mw and viscosity ) and then explore the compatibility of these polymers, including the possibility of potentially harmful aggregation effects. The research is based on a novel combination of three methods: sedimentation velocity in the analytical ultracentrifuge (SV-AUC), size-exclusion chromatography coupled to multiangle light scattering (SEC-MALS) and capillary viscometry. HA and TSP were found to have ) kg/mol and ) kg/mol respectively, and and ml/g, respectively. The structure of HA ranges from a rodlike molecule at lower molar masses changing to a random coil for Mw > 800 kg/mol, based on the Mark-Houwink-Kuhn-Sakurada (MHKS) coefficient. TSP, by contrast, is a random coil across the range of molar masses. For the mixed HA-TSP systems, SEC-MALS indicates a weak interaction. However, sedimentation coefficient (s) distributions obtained from SV-AUC measurements together with intrinsic viscosity demonstrated no evidence of any significant aggregation phenomenon, reassuring in terms of eye-drop formulation technology involving these substances.

17.
Carbohydr Polym ; 246: 116652, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32747284

RESUMEN

Polysaccharides are promising macromolecular platforms for use in the life sciences. Here, bioactive cellulose, pullulan, and dextran valproates are characterized hydrodynamically by sedimentation velocity and thermodynamically by sedimentation equilibrium analytical ultracentrifugation. Using sedimentation-diffusion analysis of sedimentation velocity experiments by numerical solution of the Lamm equation enabled the calculation of sedimentation and diffusion coefficients, and consequently molar masses. Sedimentation equilibrium experiments were then also used to determine the average molar masses. The corresponding set of data, with independently performed self-diffusion measurements by nuclear magnetic resonance spectroscopy, and together with size exclusion chromatography molar masses by coupling to refractive index-, viscometric-, and multi-angle laser light scattering detection, were subsequently correlated to each other by the hydrodynamic invariant and sedimentation parameter. We assess statistically most relevant average values of the molar masses of these polysaccharide valproates with relevant macromolecular conformational characteristics.


Asunto(s)
Celulosa/química , Dextranos/química , Glucanos/química , Ácido Valproico/química , Cromatografía en Gel , Difusión , Hidrodinámica , Cinética , Espectroscopía de Resonancia Magnética , Peso Molecular , Soluciones , Relación Estructura-Actividad , Termodinámica , Ultracentrifugación
18.
Eur J Pharm Biopharm ; 152: 340-347, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32446962

RESUMEN

PURPOSE: Insulin, in typical use, undergoes multiple changes in temperature; from refrigerator, to room temperature, to body temperature. Although long-term storage temperature has been well-studied, the short term changes to insulin are yet to be determined. Insulin detemir (IDet) is a clinically available, slow-acting, synthetic analogue characterised by the conjugation of a C14 fatty acid. The function of this modification is to cause the insulin to form multi-hexameric species, thus retarding the pharmacokinetic rate of action. In this investigation, the temperature dependence properties of this synthetic analogue is probed, as well as expiration. METHODS: Dynamic light scattering (DLS) and viscometry were employed to assess the effect of temperature upon IDet. Mass spectrometry was also used to probe the impact of shelf-life and the presence of certain excipients. RESULTS: IDet was compared with eight other insulins, including human recombinant, three fast-acting analogues and two other slow-acting analogues. Of all nine insulins, IDet was the only analogue to show temperature dependent behaviour, between 20 °C and 37 °C, when probed with non-invasive backscatter dynamic light scattering. Upon further investigation, IDet observed significant changes in size related to temperature, direction of temperature (heated/cooled) and expiration with cross-correlation observed amongst all 4 parameters. CONCLUSIONS: These findings are critical to our understanding of the behaviour of this particular clinically relevant drug, as it will allow the development of future generations of peptide-based therapies with greater clinical efficacy.


Asunto(s)
Insulina Detemir/química , Almacenaje de Medicamentos , Excipientes/química , Hipoglucemiantes/química , Temperatura
19.
Sci Rep ; 10(1): 960, 2020 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-31969624

RESUMEN

Vancomycin, a branched tricyclic glycosylated peptide antibiotic, is a last-line defence against serious infections caused by staphylococci, enterococci and other Gram-positive bacteria. Orally-administered vancomycin is the drug of choice to treat pseudomembranous enterocolitis in the gastrointestinal tract. However, the risk of vancomycin-resistant enterococcal infection or colonization is significantly associated with oral vancomycin. Using the powerful matrix-free assay of co-sedimentation analytical ultracentrifugation, reinforced by dynamic light scattering and environmental scanning electron microscopy, and with porcine mucin as the model mucin system, this is the first study to demonstrate strong interactions between vancomycin and gastric and intestinal mucins, resulting in very large aggregates and depletion of macromolecular mucin and occurring at concentrations relevant to oral dosing. In the case of another mucin which has a much lower degree of glycosylation (~60%) - bovine submaxillary mucin - a weaker but still demonstrable interaction is observed. Our demonstration - for the first time - of complexation/depletion interactions for model mucin systems with vancomycin provides the basis for further study on the implications of complexation on glycopeptide transit in humans, antibiotic bioavailability for target inhibition, in situ generation of resistance and future development strategies for absorption of the antibiotic across the mucus barrier.


Asunto(s)
Antibacterianos/farmacología , Tracto Gastrointestinal/efectos de los fármacos , Mucinas/metabolismo , Agregado de Proteínas/efectos de los fármacos , Vancomicina/farmacología , Animales , Bovinos , Tracto Gastrointestinal/metabolismo , Unión Proteica/efectos de los fármacos , Porcinos
20.
Food Biophys ; 14(3): 278-286, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31402849

RESUMEN

Submaxillary mucin is a major component that defines the makeup and functionality of saliva. Understanding its structure and function during food intake is key to designing appropriate strategies for enhancing the delivery of flavour. In the present study, the hydrodynamic integrity of bovine submaxillary mucin was characterised under physiological and acidic conditions and it was shown to have a broad molecular weight distribution with species ranging from 100 kDa to over 2000 kDa, and a random coil type of conformation. A decrease in the pH of mucin appeared to result in aggregation and a broader molecular weight distribution, which was shown to correlate with a release of flavour compounds. Our study also provides indications that p-cresol may have an effect on the macromolecular integrity of mucin.

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