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1.
Artigo em Inglês | MEDLINE | ID: mdl-38833673

RESUMO

INTRODUCTION: Current guidelines recommend pneumococcal vaccination in individuals who are over the age of 65 or are immunosuppressed due to a disease or treatment. The objective of this study was to assess vaccine uptake rates in people with inflammatory arthritis for the pneumococcal, influenza and Covid-19 vaccines and factors determining uptake. METHODS: We conducted a retrospective single centre cohort study in the UK of individuals with rheumatoid arthritis, psoriatic arthritis and axial spondylarthritis between October and December 2023. Data were collected for age, gender, co-morbidities, immunosuppressive therapies, and dates of vaccines. Logistic regression was used to evaluate predictors of vaccine uptake, with adjustments for demographic and clinical factors. RESULTS: 906 individuals were identified. 46% were receiving treatment with csDMARD, 26% on biologic monotherapy, and 23% were on both biologic and csDMARDs. 316 individuals (35%) received a pneumococcal vaccine, lower than uptake for influenza (63%) and Covid-19 (87%) vaccines. Predictors of pneumococcal vaccine uptake included age, with older patients more likely to be vaccinated (odds ratio [OR] for age ≥ 65 years: 1.67, 95% CI 1.21-2.29). Those on biological therapy demonstrated higher likelihood of vaccination (OR for biologic therapy: 1.81, 95% CI 1.33-2.47). Additional Joint committee for immunisation and vaccination (JCVI) Green Book indicators also positively influenced vaccine uptake (OR: 1.67, 95% CI 1.19-2.33). CONCLUSION: Pneumococcal vaccine uptake in inflammatory rheumatic diseases is low, especially in younger patients and those not on biological therapy. The study highlights the need for a focused approach, distinct from strategies for other vaccines, to address this public health challenge.

2.
Equine Vet J ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38689566

RESUMO

BACKGROUND: There is no objective information reporting the effect of unilateral laser ventriculocordectomy (VeC) on arytenoid abduction or stability. OBJECTIVES: To evaluate arytenoid stability and abduction in horses with severe recurrent laryngeal neuropathy (RLN) before and after unilateral laser VeC. STUDY DESIGN: Prospective cohort. METHODS: Eight horses with grade C or D exercising laryngeal function that underwent unilateral laser VeC were included. Exercising endoscopy was performed before and ≥6 weeks after left-sided laser VeC. Arytenoid stability at maximal exercise was calculated by measuring the left-to-right quotient angle ratio (LRQ) of the corniculate processes at the points of maximal arytenoid abduction (expiration) and maximal arytenoid collapse (inspiration). For each horse, means of measurements obtained for four breaths pre- and post-operatively were used for statistical analysis. RESULTS: The difference in LRQ between inspiration and expiration was lower post-operatively (median 0.039; interquartile range [IQR] 0.032-0.047) compared with pre-operatively (median 0.158; IQR 0.083-0.249; p = 0.01) confirming the left arytenoid was more stable following unilateral laser VeC. The degree of improvement was significantly greater for grade D horses compared with grade C horses (p = 0.04). The LRQ measured on maximal abduction was also lower post-operatively (median 0.467; IQR 0.444-0.506) compared with pre-operatively (median 0.578; IQR 0.554-0.655; p = 0.02) indicating the left arytenoid was less abducted following surgery. MAIN LIMITATIONS: The sample size was small, no racehorses were included and post-operative assessment was conducted at a variable time after surgery. CONCLUSION: Unilateral laser VeC in grade C and D RLN-affected horses results in slightly reduced left arytenoid abduction but increased arytenoid stability.

3.
Phys Rev E ; 109(4-1): 044112, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38755820

RESUMO

We study the equilibrium thermodynamics of quantum hard spheres in the infinite-dimensional limit, determining the boundary between liquid and glass phases in the temperature-density plane by means of the Franz-Parisi potential. We find that as the temperature decreases from high values, the effective radius of the spheres is enhanced by a multiple of the thermal de Broglie wavelength, thus increasing the effective filling fraction and decreasing the critical density for the glass phase. Numerical calculations show that the critical density continues to decrease monotonically as the temperature decreases further, suggesting that the system will form a glass at sufficiently low temperatures for any density. The methods used in this paper can be extended to more general potentials, and also to other transitions such as the Kauzman/Replica Symmetry Breaking (RSB) transition, the Gardner transition, and potentially even jamming.

4.
Vaccines (Basel) ; 12(1)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38250882

RESUMO

BACKGROUND: Vaccination against pneumococcus reduces the risk of infective events, hospitalisation, and death in individual with inflammatory arthritis, particularly in those on immunomodulating therapy who are at risk of worse outcomes from pneumococcal disease. The objective of this study was to investigate the serological protection following vaccination against pneumococcal serovars over time. Methods: This was a single centre, retrospective cohort study of individuals with rheumatoid arthritis, psoriatic arthritis, or axial spondylarthritis who had previously received the PPSV23 polysaccharide pneumococcal vaccine (Pneumovax). Data were retrieved between January 2021 to August 2023. Dates of previous pneumococcal vaccination were identified using linked primary care records. Serum serotype levels were collected. The primary outcome was serological response defined as a titre ≥0.35 mcg/mL in at least five from a total of 12 evaluated pneumococcal serovars, examined using a Luminex platform. Multivariate logistic regression models adjusting for age, gender, ethnicity, co-morbidities, and the use of prednisolone, conventional synthetic and biological DMARDs were used to determine the odds of a sustained serological response according to time categorised into ≤5 years, 5-10 years, and ≥10 years since vaccination. Results: Serological response was measured in 296 individuals with inflammatory arthritis, with rheumatoid arthritis the most common diagnosis (74% of patients). The median time between pneumococcal vaccine administration and serological assessment was 6 years (interquartile range 2.4 to 9.9). A positive serological response to at least 5 serovars was present in 195/296 (66%) of patients. Time since vaccination did not significantly associate with serological protection compared with those vaccinated <5 years, the adjusted ORs of vaccine response was 1.15 (95% CI 0.64 to 2.07) in those 5-10 years and 1.26 (95% CI: 0.64 to 2.48) in those vaccinated over 10 years ago. No individual variable from the multivariate model reached statistical significance as an independent predictor of vaccine response, although steroid use at the time of vaccine had a consistent detrimental impact on serological immunity. Conclusions: We demonstrated that antibody titres following vaccination against pneumococcal serovars do not appear to wane over time. It appears more critical to focus on maximising the initial vaccine response, which is known to be diminished in this patient population.

5.
Equine Vet J ; 2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37787374

RESUMO

BACKGROUND: Mesodiverticular bands (MDBs) are an embryonic remnant of the vitelline artery. Information about the clinical significance of equine MDBs is currently limited. OBJECTIVES: To report the clinical features, surgical findings and outcomes of horses undergoing exploratory laparotomy where a MDB was identified. STUDY DESIGN: Retrospective case series. METHODS: Case records of horses undergoing exploratory laparotomy for colic over a 14-year period (2009-2022) were reviewed. MDBs identified at laparotomy were classified as the primary or contributory cause of abdominal pain, or as incidental. RESULTS: MDBs were identified in 40/1943 horses (2.1%) and 15 were primary (32.5%), 10 contributory (25%) and 15 incidental (32.5%). Horses with primary MDBs (median 2 years, IQR 1-12) were significantly younger than horses with incidental MDBs (median 8 years, IQR 6-16; P = 0.01). MDBs were more likely to be incidental if located in the mid-jejunum (5/5) (P < 0.001) or where a mesenteric pocket was absent (11/15) (P = 0.01). Primary MDBs caused extra-mural obstruction due to mesenteric shortening (n = 4), small intestinal entrapment within the MDB pocket (n = 5) or in an adjacent mesenteric rent (n = 4), and volvulus around the MDB (n = 2), with intestinal resection required in 8/15 cases. For horses with primary MDBs, survival to hospital discharge was 60% overall (9/15) and 75% for horses that stood following anaesthesia (9/12) with 88.9% of cases discharged from hospital (8/9) surviving >1 year. Excision of MDB tissue was not associated with complications but 3/4 non-incidental MDBs left in situ required relaparotomy to treat MDB-associated colic. MAIN LIMITATIONS: Retrospective single centre data. CONCLUSIONS: Most MDBs in horses undergoing surgical treatment of colic in this population were not incidental. MDB-associated colic was most commonly classified as strangulating obstruction, but non-strangulating extra-mural compression was also identified. Excision of MDB tissue should be undertaken where possible, particularly in non-incidental cases.

6.
Angew Chem Int Ed Engl ; 61(30): e202205054, 2022 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-35595679

RESUMO

N-alkanoyl-N-methylglucamides (MEGAs) are non-toxic surfactants widely used as commercial ingredients, but more sustainable syntheses towards these compounds are highly desirable. Here, we present a biocatalytic route towards MEGAs and analogues using a truncated carboxylic acid reductase construct tailored for amide bond formation (CARmm-A). CARmm-A is capable of selective amide bond formation without the competing esterification reaction observed in lipase catalysed reactions. A kinase was implemented to regenerate ATP from polyphosphate and by thorough reaction optimisation using design of experiments, the amine concentration needed for amidation was significantly reduced. The wide substrate scope of CARmm-A was exemplified by the synthesis of 24 commercially relevant amides, including selected examples on a preparative scale. This work establishes acyl-phosphate mediated chemistry as a highly selective strategy for biocatalytic amide bond formation in the presence of multiple competing alcohol functionalities.


Assuntos
Aminas , Tensoativos , Amidas/química , Aminas/química , Biocatálise , Lipase/metabolismo
7.
Vet Surg ; 51(1): 202-213, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34724242

RESUMO

OBJECTIVE: (1) To describe the computed tomography (CT) and gross anatomy of the equine extensor carpi radialis sheath (ECRS) and common digital extensor sheath (CDETS); (2) to describe a single-portal endoscopic examination of the ECRS and CDETS. STUDY DESIGN: Ex vivo experimental. SAMPLE POPULATION: Thirty clinically normal cadaver thoracic equine limbs severed at the humeral diaphysis. METHODS: Ten limbs underwent plain and intrathecal contrast CT examinations and gross dissection of the ECRS and CDETS. Single-portal endoscopic examination of ECRS and CDETS was attempted in 4 limbs and endoscopic examination was performed on 16 limbs. Endoscopic video recordings were reviewed by 3 observers for quality of visualization before dissection and examination for iatrogenic damage. Interobserver agreement for ECRS and CDETS visualization was determined with Fleiss' κ agreement. RESULTS: Extensor carpi radialis sheath and CDETS anatomy was consistent between gross dissection and CT examinations. The ECRS endoscopic portal was medial at the level of the intersection between the extensor carpi obliquus and extensor carpi radialis tendon. The CDETS endoscopic portal was lateral, 5 cm proximal to the lateral styloid process of the ulna. The ECRS and CDETS were well visualized and interobserver agreement was substantial (κ = .73; P < .0001) and moderate (κ = .53; P < .0001), respectively. CONCLUSION: Computed tomography examinations provided useful anatomical information, consistent with gross dissection of the ECRS and CDETS. The described single-portal endoscopic techniques allowed consistent tenoscopic examination of the majority of the ECRS and CDETS. CLINICAL SIGNIFICANCE: Awareness of the intrathecal anatomy of the ECRS and CDETS should facilitate the treatment of these tendon sheaths. The proposed portals provide good to excellent single-site endoscopic visualization of the majority of the ECRS and CDETS.


Assuntos
Doenças dos Cavalos , Tendões , Animais , Cadáver , Endoscopia/veterinária , Cavalos , Tendões/diagnóstico por imagem , Tomografia Computadorizada por Raios X/veterinária , Ulna
8.
Phys Rev Lett ; 127(16): 160401, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34723583

RESUMO

The Lieb-Robinson theorem states that information propagates with a finite velocity in quantum systems on a lattice with nearest-neighbor interactions. What are the speed limits on information propagation in quantum systems with power-law interactions, which decay as 1/r^{α} at distance r? Here, we present a definitive answer to this question for all exponents α>2d and all spatial dimensions d. Schematically, information takes time at least r^{min{1,α-2d}} to propagate a distance r. As recent state transfer protocols saturate this bound, our work closes a decades-long hunt for optimal Lieb-Robinson bounds on quantum information dynamics with power-law interactions.

9.
BJPsych Bull ; : 1-4, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34348830

RESUMO

SUMMARY: Strands of thought in the philosophy of mind offer another way of looking at the nature of mental illness and how it arises from intense emotional states. Analysing the phenomenon of wonder is suggested as a novel approach to explaining delusions and variations in insight.

10.
Angew Chem Int Ed Engl ; 60(34): 18660-18665, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-33856106

RESUMO

A key aim of biocatalysis is to mimic the ability of eukaryotic cells to carry out multistep cascades in a controlled and selective way. As biocatalytic cascades get more complex, reactions become unattainable under typical batch conditions. Here a number of continuous flow systems were used to overcome batch incompatibility, thus allowing for successful biocatalytic cascades. As proof-of-principle, reactive carbonyl intermediates were generated in situ using alcohol oxidases, then passed directly to a series of packed-bed modules containing different aminating biocatalysts which accordingly produced a range of structurally distinct amines. The method was expanded to employ a batch incompatible sequential amination cascade via an oxidase/transaminase/imine reductase sequence, introducing different amine reagents at each step without cross-reactivity. The combined approaches allowed for the biocatalytic synthesis of the natural product 4O-methylnorbelladine.


Assuntos
Oxirredutases do Álcool/metabolismo , Aminas/metabolismo , Produtos Biológicos/metabolismo , Aminas/química , Biocatálise , Produtos Biológicos/química , Estrutura Molecular
11.
Phys Rev Lett ; 126(7): 070505, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33666474

RESUMO

Quantum annealing (QA) and the quantum approximate optimization algorithm (QAOA) are two special cases of the following control problem: apply a combination of two Hamiltonians to minimize the energy of a quantum state. Which is more effective has remained unclear. Here we analytically apply the framework of optimal control theory to show that generically, given a fixed amount of time, the optimal procedure has the pulsed (or "bang-bang") structure of QAOA at the beginning and end but can have a smooth annealing structure in between. This is in contrast to previous works which have suggested that bang-bang (i.e., QAOA) protocols are ideal. To support this theoretical work, we carry out simulations of various transverse field Ising models, demonstrating that bang-anneal-bang protocols are more common. The general features identified here provide guideposts for the nascent experimental implementations of quantum optimization algorithms.

12.
Angew Chem Weinheim Bergstr Ger ; 133(34): 18808-18813, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-38505092

RESUMO

A key aim of biocatalysis is to mimic the ability of eukaryotic cells to carry out multistep cascades in a controlled and selective way. As biocatalytic cascades get more complex, reactions become unattainable under typical batch conditions. Here a number of continuous flow systems were used to overcome batch incompatibility, thus allowing for successful biocatalytic cascades. As proof-of-principle, reactive carbonyl intermediates were generated in situ using alcohol oxidases, then passed directly to a series of packed-bed modules containing different aminating biocatalysts which accordingly produced a range of structurally distinct amines. The method was expanded to employ a batch incompatible sequential amination cascade via an oxidase/transaminase/imine reductase sequence, introducing different amine reagents at each step without cross-reactivity. The combined approaches allowed for the biocatalytic synthesis of the natural product 4O-methylnorbelladine.

13.
Proc Natl Acad Sci U S A ; 117(41): 25396-25401, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33024018

RESUMO

Quantum computers and simulators may offer significant advantages over their classical counterparts, providing insights into quantum many-body systems and possibly improving performance for solving exponentially hard problems, such as optimization and satisfiability. Here, we report the implementation of a low-depth Quantum Approximate Optimization Algorithm (QAOA) using an analog quantum simulator. We estimate the ground-state energy of the Transverse Field Ising Model with long-range interactions with tunable range, and we optimize the corresponding combinatorial classical problem by sampling the QAOA output with high-fidelity, single-shot, individual qubit measurements. We execute the algorithm with both an exhaustive search and closed-loop optimization of the variational parameters, approximating the ground-state energy with up to 40 trapped-ion qubits. We benchmark the experiment with bootstrapping heuristic methods scaling polynomially with the system size. We observe, in agreement with numerics, that the QAOA performance does not degrade significantly as we scale up the system size and that the runtime is approximately independent from the number of qubits. We finally give a comprehensive analysis of the errors occurring in our system, a crucial step in the path forward toward the application of the QAOA to more general problem instances.

14.
Chem Commun (Camb) ; 56(57): 7949-7952, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32531011

RESUMO

Multi-enzyme cascades utilising variants of galactose oxidase and imine reductase led to the successful conversion of N-Cbz-protected l-ornithinol and l-lysinol to l-3-N-Cbz-aminopiperidine and l-3-N-Cbz-aminoazepane respectively, in up to 54% isolated yield. Streamlining the reactions into one-pot prevented potential racemisation of key labile intermediates and led to products with high enantiopurity.


Assuntos
Azepinas/metabolismo , Galactose Oxidase/metabolismo , Iminas/metabolismo , Oxirredutases/metabolismo , Piperidinas/metabolismo , Azepinas/química , Estrutura Molecular , Piperidinas/química
15.
RSC Adv ; 10(33): 19501-19505, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35515476

RESUMO

The generation of immobilised oxidase biocatalysts allowing multifunctional oxidation of valuable chemicals using molecular oxygen is described. Engineered galactose oxidase (GOase) variants M1 and M3-5, an engineered choline oxidase (AcCO6) and monoamine oxidase (MAO-N D9) displayed long-term stability and reusability over several weeks when covalently attached on a solid support, outperforming their free counterparts in terms of stability (more than 20 fold), resistance to heat at 60 °C, and tolerance to neat organic solvents such as hexane and toluene. These robust heterogenous oxidation catalysts can be recovered after each reaction and be reused multiple times for the oxidation of different substrates.

16.
Soft Matter ; 12(10): 2676-87, 2016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26742483

RESUMO

The cytoskeleton, despite comprising relatively few building blocks, drives an impressive variety of cellular phenomena ranging from cell division to motility. These building blocks include filaments, motor proteins, and static crosslinkers. Outside of cells, these same components can form novel materials exhibiting active flows and nonequilibrium contraction or extension. While dipolar extensile or contractile active stresses are common in nematic motor-filament systems, their microscopic origin remains unclear. Here we study a minimal physical model of filaments, crosslinking motors, and static crosslinkers to dissect the microscopic mechanisms of stress generation in a two-dimensional system of orientationally aligned rods. We demonstrate the essential role of filament steric interactions which have not previously been considered to significantly contribute to active stresses. With this insight, we are able to tune contractile or extensile behavior through the control of motor-driven filament sliding and crosslinking. This work provides a roadmap for engineering stresses in active liquid crystals. The mechanisms we study may help explain why flowing nematic motor-filament mixtures are extensile while gelled systems are contractile.


Assuntos
Citoesqueleto/química , Cristais Líquidos/química , Microtúbulos/química , Proteínas Motores Moleculares/química , Animais , Anisotropia , Movimento Celular , Simulação por Computador , Humanos , Modelos Biológicos , Modelos Moleculares
17.
J Phys Chem Lett ; 5(8): 1347-54, 2014 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-26269978

RESUMO

A consequence of thermal diffusion is that heat, even when applied to a localized region of space, has the tendency to produce a temperature change that is spatially uniform throughout a material with a thermal conductivity that is much larger than that of its environment. This implies that the degree of spatial correlation between the heat power supplied and the temperature change that it induces is likely to be small. Here, we show, via theory and simulation, that through a Fano interference, temperature changes can be both localized and controllably directed within certain plasmon-supporting metal nanoparticle assemblies. This occurs even when all particles are composed of the same material and contained within the same diffraction-limited spot. These anomalous thermal properties are compared and contrasted across three different nanosystems, the coupled nanorod-antenna, the heterorod dimer, and the nanocube on a substrate, known to support both spatial and spectral Fano interferences. We conclude that the presence of a Fano resonance is not sufficient by itself to induce a controllably nanolocalized temperature change. However, when present in a nanosystem of the right composition and morphology, temperature changes can be manipulated with nanoscale precision, despite thermal diffusion.

18.
Mol Immunol ; 54(2): 227-32, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23291145

RESUMO

The aetiology of Pigeon Fanciers' Lung (PFL) is believed to include immune complex formation between inhaled pigeon antigens and antibodies generated against them. However it is unclear why some fanciers are asymptomatic despite the presence of high levels of anti-avian antigen antibodies in their serum. In this study we investigated whether qualitative differences in specific antibodies might contribute to disease. IgG responses among pigeon fanciers were determined by ELISA and the functional affinity of IgG1 and IgG2 against a range of pigeon antigens was determined by inhibition ELISA and Isothermal Titration Calorimetry (ITC). The median titres of IgG1 and IgG2 against all the pigeon antigens tested was higher in asymptomatic than symptomatic fanciers and these differences were significant for anti-pigeon serum IgG1 (P=0.04), anti-fresh pigeon droppings (PDF) IgG2 (P=0.028), anti-old pigeon droppings (PDO) IgG2 (P=0.04) and anti-pigeon intestinal scrapings IgG2 (P=0.03). The functional affinity of IgG1 and IgG2 against PDO was higher in symptomatic individuals (P=0.006 and P=0.002, respectively) whilst the functional affinity of anti-PDF IgG2 was also significantly higher in these patients (P≤0.001). Symptomatic fanciers were also significantly more likely to have a high reaction enthalphy (ΔH) as measured by ITC and thus had higher affinity antibodies against PDO (P=0.044). This data confirms previous studies showing that the magnitude alone of the antibody response to pigeon antigens cannot determine the presence of PFL, but that antibody affinity may be important. ITC is a rapid method of measuring antibody affinity and has diagnostic potential in PFL, and may be of use in other situations where antibody affinity is important.


Assuntos
Anticorpos/imunologia , Antígenos/imunologia , Pulmão do Criador de Aves/imunologia , Adulto , Idoso , Animais , Anticorpos/sangue , Afinidade de Anticorpos/imunologia , Columbidae/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
19.
Mar Environ Res ; 70(5): 368-73, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20727579

RESUMO

Monitoring effects of contaminants at lower levels of biological organisation (e.g. biochemical and cellular) allows for mechanistic evaluation of effects of contaminant exposure through laboratory exposures. However, higher level organism effects (e.g. physiological and behavioural) are deemed more ecologically-relevant. In the present study, cellular (cell viability and immune function), physiological (cardiac activity) and behavioural (foraging behaviour) responses were evaluated in field-collected shore crabs Carcinus maenas from three estuaries [a 'relatively' (polycyclic aromatic hydrocarbon) PAH-contaminated site (Plym Estuary) and two 'comparatively clean' field sites (Avon and Yealm Estuaries)] and compared with responses of crabs exposed in the laboratory to a model organic contaminant (PAH) pyrene (200 µg l(-1) for 28 days). The hypothesis that behavioural indicators may be more sensitive than other more traditional methods was tested. No significant impacts were observed at the cellular or physiological level in Plym-collected crabs (the 'relatively' contaminated site), but foraging behaviour was significantly altered (increased prey handling time) compared to individuals collected from the 'relatively' uncontaminated sites (Avon and Yealm). When given a cockle as a prey item, both Plym-collected and laboratory-exposed crabs took longer to handle and break into cockle shells. Therefore, ecologically-relevant behavioural observations may serve as valuableindicators of environmental quality.


Assuntos
Comportamento Animal/efeitos dos fármacos , Braquiúros/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Animais , Sobrevivência Celular , Comportamento Alimentar/efeitos dos fármacos , Masculino , Pirenos/toxicidade
20.
Ann Plast Surg ; 62(1): 92-6, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19131729

RESUMO

Topical negative pressure is an effective technique to promote wound healing and the integration of skin graft and synthetic dermal equivalents. We describe an in vitro model to investigate the effect of negative pressure on angiogenesis, a pivotal step. Dermal fibroblasts or human microvascular endothelial cells were cultured on Integra and subjected to intermittent or continuous negative pressure. At fixed intervals of over 120 hours, the Integra was fixed and assessed for cell migration (microscopy), cell viability (MTS assay), and cell proliferation (Ki67 immunostaining). Under control conditions, endothelial cells formed a monolayer and failed to ingress, whereas fibroblasts migrated throughout the Integra within 24 hours. Negative pressure switches endothelial cell to a migratory and proliferative phenotype. Ingress is greatest with intermittent rather than continuous negative pressure. It has no effect on dermal fibroblast function. This study identifies an important, potential pro-angiogenic mechanism by which topical negative pressure promotes wound healing.


Assuntos
Movimento Celular , Proliferação de Células , Sulfatos de Condroitina , Colágeno , Células Endoteliais/fisiologia , Tratamento de Ferimentos com Pressão Negativa , Cicatrização , Células Cultivadas , Endotélio Vascular/citologia , Fibroblastos/fisiologia , Humanos
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