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1.
Mol Pharm ; 14(7): 2378-2389, 2017 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-28605595

RESUMO

The novel self-assembling bottlebrush polyethylene glycol-polynorbornene-thiocresol block copolymers (PEG-PNB-TC) were synthesized by the ring opening metathesis polymerization (ROMP), followed by functionalization of the polymer backbone via the thio-bromo "click" postpolymerization strategy. The PEG-PNB-TC copolymers could easily self-assemble into the nanoscale core-shell polymeric micelles. The hydrophobic anticancer drugs, such as paclitaxel (PTX), could be loaded into their hydrophobic core to form a stable drug-loaded micelle with a superior drug loading capacity of up to ∼35% (w/w). The sustained drug release behavior of the PEG-PNB-TC micelles was observed under a simulated "sink condition". Compared with commercial PTX formulation (Taxol), the PTX-loaded PEG-PNB-TC micelles showed the enhanced in vitro cellular uptake and comparable cytotoxicity in the drug-sensitive cancer cells, while the copolymers were much safer than Cremophor EL, the surfactant used in Taxol. Furthermore, curcumin (CUR), a natural chemotherapy drug sensitizer, was successfully coloaded with PTX into the PEG-PNB-TC micelles. High drug loading capacity of the PEG-PNB-TC micelles allowed for easy adjustment of drug doses and the ratio of the coloaded drugs. The combination of PTX and CUR showed synergistic anticancer effect in both the drug mixture and drug coloaded micelles at high CUR/PTX ratio, while low CRU/PTX ratio only exhibited additive effects. The combinatorial effects remarkably circumvented the PTX resistance in the multidrug resistant (MDR) cancer cells. Due to the easy polymerization and functionalization, excellent self-assembly capability, high drug loading capability, and great stability, the PEG-PNB-TC copolymers might be a promising nanomaterial for delivery of the hydrophobic anticancer drugs, especially for combination drug therapy.


Assuntos
Antineoplásicos/farmacologia , Curcumina/farmacologia , Micelas , Paclitaxel/farmacologia , Polímeros/química , Células A549 , Antineoplásicos/administração & dosagem , Cromatografia Líquida de Alta Pressão , Curcumina/administração & dosagem , Células HeLa , Humanos , Paclitaxel/administração & dosagem , Plásticos/química
2.
BMC Genomics ; 17(1): 1048, 2016 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-27993130

RESUMO

BACKGROUND: Many gram-negative bacteria use type III secretion systems (T3SSs) to translocate effector proteins into host cells. T3SS effectors can give some bacteria a competitive edge over others within the same environment and can help bacteria to invade the host cells and allow them to multiply rapidly within the host. Therefore, developing efficient methods to identify effectors scattered in bacterial genomes can lead to a better understanding of host-pathogen interactions and ultimately to important medical and biotechnological applications. RESULTS: We used 21 genomic and proteomic attributes to create a precise and reliable T3SS effector prediction method called Genome Search for Effectors Tool (GenSET). Five machine learning algorithms were trained on effectors selected from different organisms and a trained (voting) algorithm was then applied to identify other effectors present in the genome testing sets from the same (GenSET Phase 1) or different (GenSET Phase 2) organism. Although a select group of attributes that included the codon adaptation index, probability of expression in inclusion bodies, N-terminal disorder, and G + C content (filtered) were better at discriminating between positive and negative sets, algorithm performance was better when all 21 attributes (unfiltered) were used. Performance scores (sensitivity, specificity and area under the curve) from GenSET Phase 1 were better than those reported for six published methods. More importantly, GenSET Phase 1 ranked more known effectors (70.3%) in the top 40 ranked proteins and predicted 10-80% more effectors than three available programs in three of the four organisms tested. GenSET Phase 2 predicted 43.8% effectors in the top 40 ranked proteins when tested on four related or unrelated organisms. The lower prediction rates from GenSET Phase 2 may be due to the presence of different translocation signals in effectors from different T3SS families. CONCLUSIONS: The species-specific GenSET Phase 1 method offers an alternative approach to T3SS effector prediction that can be used with other published programs to improve effector predictions. Additionally, our approach can be applied to predict effectors of other secretion systems as long as these effectors have translocation signals embedded in their sequences.


Assuntos
Biologia Computacional , Genoma Bacteriano , Genômica , Sistemas de Secreção Tipo III , Algoritmos , Composição de Bases , Biologia Computacional/métodos , Genômica/métodos , Bactérias Gram-Negativas/genética , Reprodutibilidade dos Testes
3.
BMC Bioinformatics ; 15: 344, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25359149

RESUMO

BACKGROUND: A typical affinity purification coupled to mass spectrometry (AP-MS) experiment includes the purification of a target protein (bait) using an antibody and subsequent mass spectrometry analysis of all proteins co-purifying with the bait (aka prey proteins). Like any other systems biology approach, AP-MS experiments generate a lot of data and visualization has been challenging, especially when integrating AP-MS experiments with orthogonal datasets. RESULTS: We present Circular Interaction Graph for Proteomics (CIG-P), which generates circular diagrams for visually appealing final representation of AP-MS data. Through a Java based GUI, the user inputs experimental and reference data as file in csv format. The resulting circular representation can be manipulated live within the GUI before exporting the diagram as vector graphic in pdf format. The strength of CIG-P is the ability to integrate orthogonal datasets with each other, e.g. affinity purification data of kinase PRPF4B in relation to the functional components of the spliceosome. Further, various AP-MS experiments can be compared to each other. CONCLUSIONS: CIG-P aids to present AP-MS data to a wider audience and we envision that the tool finds other applications too, e.g. kinase - substrate relationships as a function of perturbation. CIG-P is available under: http://sourceforge.net/projects/cig-p/


Assuntos
Espectrometria de Massas/métodos , Mapeamento de Interação de Proteínas/métodos , Proteínas Quinases/metabolismo , Proteômica/métodos , Cromatografia de Afinidade/métodos , Gráficos por Computador , Humanos
4.
BMC Pediatr ; 14: 128, 2014 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-24884914

RESUMO

BACKGROUND: There is uncertainty about the nature and specificity of physical signs following anal child sexual abuse. The study investigates the extent to which physical findings discriminate between children with and without a history of anal abuse. METHODS: Retrospective case note review in a paediatric forensic unit. CASES: all eligible cases from 1990 to 2007 alleging anal abuse. CONTROLS: all children examined anally from 1998 to 2007 with possible physical abuse or neglect with no identified concern regarding sexual abuse. Fisher's exact test (two-tailed) was performed to ascertain the significance of differences for individual signs between cases and controls. To explore the potential role of confounding, logistic regression was used to produce odds ratios adjusted for age and gender. RESULTS: A total of 184 cases (105 boys, 79 girls), average age 98.5 months (range 26 to 179) were compared with 179 controls (94 boys, 85 girls) average age 83.7 months (range 35-193). Of the cases 136 (74%) had one or more signs described in anal abuse, compared to 29 (16%) controls. 79 (43%) cases and 2 (1.1%) controls had >1 sign. Reflex anal dilatation (RAD) and venous congestion were seen in 22% and 36% of cases but <1% of controls (likelihood ratios (LR) 40, 60 respectively), anal fissure in 14% cases and 1.1% controls (LR 13), anal laxity in 27% cases and 3% controls (LR 10).Novel signs seen significantly more commonly in cases were anal fold changes, swelling and twitching. Erythema, swelling and fold changes were seen most commonly within 7 days of last reported contact; RAD, laxity, venous congestion, fissure and twitching were observed up to 6 months after the alleged assault. CONCLUSIONS: Anal findings are more common in children alleging anal abuse than in those presenting with physical abuse or neglect with no concern about sexual abuse. Multiple signs are rare in controls and support disclosed anal abuse.


Assuntos
Canal Anal/lesões , Canal Anal/patologia , Abuso Sexual na Infância/diagnóstico , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Dilatação Patológica , Inglaterra , Eritema/patologia , Feminino , Fissura Anal/patologia , Medicina Legal , Humanos , Hiperemia/patologia , Masculino , Exame Físico , Reflexo Anormal , Estudos Retrospectivos
5.
Nanoscale ; 16(13): 6696-6707, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38487903

RESUMO

Two spherical nanoparticulate materials were prepared by base-catalyzed sol-gel hydrolysis/self-condensation of the bis-Cinchona alkaloid-phthalazine-based bridged bis(triethoxysilanes). For the purpose of comparing the catalytic properties, two compact materials were also prepared from the same precursors using a fluoride-catalyzed sol-gel process. All materials were characterized by SEM, TEM, solid-state 29Si NMR and 13C NMR, TGA, and FTIR. The prepared silsesquioxane-based materials were studied as potential heterogeneous catalysts for selected enantioselective reactions. The spherical material with regularly incorporated bis-quinine-phthalazine chiral units exhibited good to excellent enantioselectivities in osmium-catalyzed dihydroxylations of alkenes. Enantioselectivities observed in dihydroxylations of aromatic trans-alkenes were as excellent as those observed with the homogeneous catalyst (DHQ)2-PHAL. One compact and one nanoparticulate material was successfully recycled and reused five times without loss of enantioselectivity. Furthermore, both quinine-based and cinchonine-based materials were tested as heterogeneous organocatalysts for chlorolactonization of 4-arylpent-4-enoic acids. The materials showed only moderate enantioselectivities; however, these are the first heterogeneous catalysts for enantioselective chlorolactonization published so far.

6.
Bioorg Med Chem Lett ; 23(19): 5279-82, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23973169

RESUMO

A series of dipeptide derivatives of L-dopa were synthesized and investigated for their pharmacological activity using the unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rat as an experimental model of Parkinson's disease. Among them, (S)-isopropyl 2-(2-amino-2-methylpropanamido)-3-(3,4-dihydroxyphenyl)propanoate (4 g) was found to be the most active compound, with 106% AUC activity and 149% peak activity of L-dopa after oral administration.


Assuntos
Antiparkinsonianos/síntese química , Dipeptídeos/síntese química , Desenho de Fármacos , Levodopa/análogos & derivados , Levodopa/síntese química , Peptídeos , Animais , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/farmacologia , Dipeptídeos/administração & dosagem , Dipeptídeos/farmacologia , Modelos Animais de Doenças , Levodopa/administração & dosagem , Levodopa/farmacologia , Masculino , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , Peptídeos/administração & dosagem , Peptídeos/síntese química , Peptídeos/farmacologia , Ratos , Ratos Wistar
7.
Adv Biochem Eng Biotechnol ; 184: 285-356, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37468715

RESUMO

The human uses of mushrooms and cultured mycelium products for nutrition and medicine are detailed and supported by available human studies, which in many cases are clinical trials published in peer-reviewed journals. The major medically active immunomodulating compounds in the cell walls-chitin, beta-glucans, and glycoproteins, as well as lower weight molecules-nitrogen-containing compounds, phenolics, and terpenes-are discussed in relation to their current clinical uses. The nutritional content and foods derived from mushrooms, particularly related to their medical benefits, are discussed. High-quality major nutrients such as the high amounts of complete protein and prebiotic fibers found in edible and medicinal fungi and their products are presented. Mushrooms contain the highest amount of valuable medicinal fiber, while dried fruiting bodies of some fungi have up to 80% prebiotic fiber. These fibers are particularly complex and are not broken down in the upper gut, so they can diversify the microbiome and increase the most beneficial species, leading to better immune regulation and increasing normalizing levels of crucial neurotransmitters like serotonin and dopamine. Since the growth of medicinal mushroom products is expanding rapidly worldwide, attention is placed on reviewing important aspects of mushroom and mycelium cultivation and quality issues relating to adulteration, substitution, and purity and for maximizing medicinal potency. Common questions surrounding medicinal mushroom products in the marketplace, particularly the healing potential of fungal mycelium compared with fruiting bodies, extraction methods, and the use of fillers in products, are all explored, and many points are supported by the literature.


Assuntos
Agaricales , Produtos Biológicos , Humanos , Produtos Biológicos/farmacologia
8.
Eur J Pediatr ; 171(5): 751-5, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22069148

RESUMO

UNLABELLED: Child sexual abuse is increasingly recognised in all societies, affecting boys and girls alike in all age groups and often involving oral, anal and vaginal penetration. The presence of physical evidence following suspected child sexual abuse is important in confirming the diagnosis and providing legal corroboration that abuse has occurred. Whilst many children have no physical evidence, its presence should be carefully sought and documented by skilled examination, regardless of the time interval between any suspected abuse and the examination. When examination is close to the time of the abuse, forensic sampling may be required. Although many children have no physical findings, understanding the significance of physical findings has increased with both experience and research, although certainty and agreement is lacking in some areas. There are few case control studies of abused and non-abused children where standard terminology, examination method and description allow for meaningful comparison. CONCLUSIONS: Physical findings rarely provide conclusive evidence of sexual abuse in isolation but may offer important pieces of the diagnostic "jigsaw picture".


Assuntos
Abuso Sexual na Infância/diagnóstico , Genitália Feminina/lesões , Genitália Masculina/lesões , Exame Físico/métodos , Criança , Feminino , Humanos , Masculino , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/transmissão
9.
J Org Chem ; 76(2): 523-33, 2011 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21192646

RESUMO

The design of functional soluble polyolefins for use as supports for salen ligands and metal complexes is described. Examples and applications that use both polyisobutylene (PIB)- and polyethylene (PE(Olig))-bound recoverable/recyclable salen ligands/metal complexes are detailed. In the case of using PIB as a support, the polymer-bound complexes can be recovered through the use of latent biphasic or a thermomorphic mixed solvent systems. In the case of PE(Olig)-supported complexes, the thermomorphic PE(Olig)-bound salen species can be dissolved in "hot" solvents and quantitatively recovered as solids upon cooling to room temperature. Both the PIB- and PE(Olig)-bound salen catalysts were shown to catalyze the ring-opening of epoxides with various nucleophiles. Both sorts of polyolefin-bound catalysts can be recycled and reused with no observed loss in activity. However, limitations of catalyst concentration make chiral versions of these complexes uncompetitive in comparison to conventional chiral salen catalysts that can be used in neat substrate at higher concentration to produce high enantioselectivity in the ring-opening products. The preparation of a PIB-bound "half-salen" catalyst was also briefly examined.

10.
J Org Chem ; 76(16): 6912-7, 2011 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-21714575

RESUMO

Phosphines are important as catalysts or reagents in synthesis but must be separated from products after a reaction. This report shows that polyisobutylene (PIB)-bound alkyldiaryl- and triarylphosphines are useful as catalysts in addition and allylic amination reactions or as reagents in aza-Wittig and Mitsunobu reactions. Heptane solutions of such phosphines and their oxidized byproducts can be easily separated from polar solutions of organic products, and PIB-phosphine oxides formed during a reaction can readily be reduced to PIB-phosphines for reuse.

11.
J Acoust Soc Am ; 127(6): 3347-55, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20550235

RESUMO

Human perception of sonic booms is a major impediment to commercial supersonic flight. Shaping, which reduces the audible shock waves of a boom, can make outdoor perception of booms acceptable. Perception of sonic booms experienced indoors is of concern, and it is not yet established whether shaped booms offer benefit to indoor listeners. A better understanding of the transmission of shaped booms into building structures is needed. In the authors' earlier work the vibration response of house elements subjected to different sonic boom wave shapes was evaluated using a single degree of freedom model. This paper expands that approach with a modal analysis model. The acceleration of building elements and the resulting sound pressure inside a room are computed in the time and frequency domains. Analytical results are compared with experimental data measured by NASA during sonic boom tests conducted at Edwards Air Force Base in 2007. The effects of wave signature parameters on transmission are studied to evaluate the advantages of various kinds of minimized boom shapes.


Assuntos
Acústica , Aeronaves , Arquitetura , Habitação , Modelos Teóricos , Ruído dos Transportes , Algoritmos , Percepção Auditiva , Humanos , Pressão , Software , Design de Software , Fatores de Tempo , Estados Unidos , United States National Aeronautics and Space Administration
12.
Polymers (Basel) ; 12(6)2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32486087

RESUMO

This communication describes our recent efforts to utilize Wittig olefination reactions for the post-polymerization modification of polynorbornene derivatives prepared through ring opening metathesis polymerization (ROMP). Polymerizing α-bromo ester-containing norbornenes provides polymers that can undergo facile substitution with triphenylphosphine. The resulting polymeric phosphonium salt is then deprotonated to form an ylide that undergoes reaction with various aryl aldehydes in a one-pot fashion to yield the respective cinnamates. These materials can undergo further modification through photo-induced [2 + 2] cycloaddition cross-linking reactions.

13.
Chempluschem ; 85(5): 876-888, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32391654

RESUMO

Cyclodextrins, which are glucose-based cyclic oligosaccharides, are materials that can act inherently as chiral selectors, with many reports of the application of cyclodextrins in enantioseparation. However, many studies have encountered the problem of insufficient enantioselective performance of the chiral selector. One of the main reasons is due to low surface concertation's, whereby interaction between the chiral selector and analyte usually occurs at a surface. Thus, scientists have been trying for the last two decades to overcome this problem, with the incorporation of nanomaterials being promising as they possess a large surface area which allows for the accommodation of a higher concentration of the chiral selectors. Herein, we outline nanomaterial-cyclodextrin conjugates that work in tandem to achieve or enhance enantioselectivity through various methods such as chromatography, adsorption, and removal using magnetic nanoparticles, or enantiorecognition using electrochemical techniques.

14.
Pharmaceutics ; 12(12)2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339452

RESUMO

Nonviral vectors offer a safe alternative to viral vectors for gene therapy applications, albeit typically exhibiting lower transfection efficiencies. As a result, there remains a significant need for the development of a nonviral delivery system with low cytotoxicity and high transfection efficacy as a tool for safe and transient gene delivery. This study assesses MgAl-NO3 layered double hydroxide (LDH) as a nonviral vector to deliver nucleic acids (pDNA, miRNA and siRNA) to mesenchymal stromal cells (MSCs) in 2D culture and using a 3D tissue engineering scaffold approach. Nanoparticles were formulated by complexing LDH with pDNA, microRNA (miRNA) mimics and inhibitors, and siRNA at varying mass ratios of LDH:nucleic acid. In 2D monolayer, pDNA delivery demonstrated significant cytotoxicity issues, and low cellular transfection was deemed to be a result of the poor physicochemical properties of the LDH-pDNA nanoparticles. However, the lower mass ratios required to successfully complex with miRNA and siRNA cargo allowed for efficient delivery to MSCs. Furthermore, incorporation of LDH-miRNA nanoparticles into collagen-nanohydroxyapatite scaffolds resulted in successful overexpression of miRNA in MSCs, demonstrating the development of an efficacious miRNA delivery platform for gene therapy applications in regenerative medicine.

15.
Biomaterials ; 239: 119833, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32062479

RESUMO

Engineering a pro-regenerative immune response following scaffold implantation is integral to functional tissue regeneration. The immune response to implanted biomaterials is determined by multiple factors, including biophysical cues such as material stiffness, topography and particle size. In this study we developed an immune modulating scaffold for bone defect healing containing bone mimetic nano hydroxyapatite particles (BMnP). We first demonstrate that, in contrast to commercially available micron-sized hydroxyapatite particles, in-house generated BMnP preferentially polarize human macrophages towards an M2 phenotype, activate the transcription factor cMaf and specifically enhance production of the anti-inflammatory cytokine, IL-10. Furthermore, nano-particle treated macrophages enhance mesenchymal stem cell (MSC) osteogenesis in vitro and this occurs in an IL-10 dependent manner, demonstrating a direct pro-osteogenic role for this cytokine. BMnPs were also capable of driving pro-angiogenic responses in human macrophages and HUVECs. Characterization of immune cell subsets following incorporation of functionalized scaffolds into a rat femoral defect model revealed a similar profile, with micron-sized hydroxyapatite functionalized scaffolds eliciting pro-inflammatory responses characterized by infiltrating T cells and elevated expression of M1 macrophages markers compared to BMnP functionalized scaffolds which promoted M2 macrophage polarization, tissue vascularization and increased bone volume. Taken together these results demonstrate that nano-sized Hydroxyapatite has immunomodulatory potential and is capable of directing anti-inflammatory innate immune-mediated responses that are associated with tissue repair and regeneration.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Animais , Regeneração Óssea , Interleucina-10 , Ativação de Macrófagos , Macrófagos , Ratos , Alicerces Teciduais
16.
Pediatr Radiol ; 39(5): 457-60, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19198825

RESUMO

Radiologists play a key role in the recognition of child abuse. In the last century, radiologists pioneered the identification of nonaccidental injuries, including fractures and brain injury, and together with colleagues in paediatrics advocated the protection of children from abuse. Prevalence studies in many countries have revealed the widespread and hidden nature of child maltreatment. New and complex forms of abuse, e.g. fabricated or induced illness, have been recognized. Physical abuse affects 7-9% of children in the UK, although fewer suffer the severe or life-threatening injuries seen by radiologists. A high index of suspicion of nonaccidental trauma is required where known patterns of injury or inconsistencies of presentation and history are detected. In many cases the diagnosis is readily made, although some cases remain contentious or controversial and consume much clinical time and energy. Differences of view between doctors are tested in the courts. Adverse publicity has made this work unpopular in the UK. Knowledge of the differential diagnosis of unexplained or apparent injury is essential for accurate diagnosis, vital where errors in either direction can be disastrous. New UK radiological guidelines will assist radiologists in achieving best evidence-based practice.


Assuntos
Maus-Tratos Infantis/diagnóstico , Maus-Tratos Infantis/estatística & dados numéricos , Diagnóstico por Imagem/métodos , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/epidemiologia , Acidentes , Criança , Maus-Tratos Infantis/prevenção & controle , Humanos , Incidência , Pediatria/métodos , Ferimentos e Lesões/prevenção & controle
17.
Polymers (Basel) ; 11(2)2019 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-30960208

RESUMO

It would be difficult to imagine how modern life across the globe would operate in the absence of synthetic polymers. Although these materials (mostly in the form of plastics) have revolutionized our daily lives, there are consequences to their use, one of these being their high levels of flammability. For this reason, research into the development of flame retardant (FR) additives for these materials is of tremendous importance. However, many of the FRs prepared are problematic due to their negative impacts on human health and the environment. Furthermore, their preparations are neither green nor sustainable since they require typical organic synthetic processes that rely on fossil fuels. Because of this, the need to develop more sustainable and non-toxic options is vital. Many research groups have turned their attention to preparing new bio-based FR additives for synthetic polymers. This review explores some of the recent examples made in this field.

18.
Biomaterials ; 197: 405-416, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30708184

RESUMO

The bone infection osteomyelitis (typically by Staphylococcus aureus) usually requires a multistep procedure of surgical debridement, long-term systemic high-dose antibiotics, and - for larger defects - bone grafting. This, combined with the alarming rise in antibiotic resistance, necessitates development of alternative approaches. Herein, we describe a one-step treatment for osteomyelitis that combines local, controlled release of non-antibiotic antibacterials with a regenerative collagen-based scaffold. To maximise efficacy, we utilised bioactive glass, an established osteoconductive material with immense capacity for bone repair, as a delivery platform for copper ions (proven antibacterial, angiogenic, and osteogenic properties). Multifunctional collagen-copper-doped bioactive glass scaffolds (CuBG-CS) were fabricated with favourable microarchitectural and mechanical properties (up to 1.9-fold increase in compressive modulus over CS) within the ideal range for bone tissue engineering. Scaffolds demonstrated antibacterial activity against Staphylococcus aureus (up to 66% inhibition) whilst also enhancing osteogenesis (up to 3.6-fold increase in calcium deposition) and angiogenesis in vitro. Most significantly, when assessed in a chick embryo in vivo model, CuBG-CS not only demonstrated biocompatibility, but also a significant angiogenic and osteogenic response, consistent with in vitro studies. Collectively, these results indicate that the CuBG-CS developed here show potential as a one-step osteomyelitis treatment: reducing infection, whilst enhancing bone healing.


Assuntos
Indutores da Angiogênese/administração & dosagem , Antibacterianos/administração & dosagem , Colágeno/química , Cobre/administração & dosagem , Osteogênese/efeitos dos fármacos , Alicerces Teciduais/química , Indutores da Angiogênese/farmacologia , Animais , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Linhagem Celular , Embrião de Galinha , Cobre/farmacologia , Sistemas de Liberação de Medicamentos , Vidro/química , Camundongos , Neovascularização Fisiológica/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos
19.
Proteins ; 73(4): 929-40, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18536014

RESUMO

SH2 domains provide fundamental recognition sites in tyrosine kinase-mediated signaling pathways which, when aberrant, give rise to disease states such as cancer, diabetes, and immune deficiency. Designing specific inhibitors that target the SH2 domain-binding site, however, have presented a major challenge. Despite well over a decade of intensive research, clinically useful SH2 domain inhibitors have yet to become available. A better understanding of the structural, dynamic, and thermodynamic contributions to ligand binding of individual SH2 domains will provide some insight as to whether inhibitor development is possible. We report the first high resolution solution structure of the apo-v-Src SH2 domain. This is accompanied by the analysis of backbone dynamics and pK(a) values within the apo- and peptide-bound states. Our results indicate that the phosphotyrosine (pY) pocket is tightly structured and hence not adaptable to exogenous ligands. On the other hand, the pocket which accommodates residues proximal and C-terminal of the pY (pY + 3) or so-called specificity determining region, is a large dynamic-binding surface. This appears to allow a high level of promiscuity in binding. Binding of a series of synthetic, phosphotyrosyl, peptidomimetic compounds designed to explore interactions in the pY + 3 pocket further demonstrates the ability of the SH2 domain to accommodate diverse ligands. The thermodynamic parameters of these interactions show dramatic enthalpy/entropy compensation. These data suggest that the v-Src SH2 domain does not have a highly specific secondary-binding site, which clearly presents a major hurdle to design selective inhibitors.


Assuntos
Desenho de Fármacos , Proteína Oncogênica pp60(v-src)/química , Proteína Oncogênica pp60(v-src)/metabolismo , Amidas/química , Sequência de Aminoácidos , Sítios de Ligação , Calorimetria , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Ligantes , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Peptídeos/química , Fosfotirosina/química , Ligação Proteica , Estrutura Secundária de Proteína , Soluções , Termodinâmica , Domínios de Homologia de src
20.
Laryngoscope ; 118(3): 459-63, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18043489

RESUMO

BACKGROUND: Human papillomavirus (HPV) is known to infect the epithelium of the upper aerodigestive tract; however, major questions regarding prevalence and persistence of infection, and their relation to local immune response, remain unanswered. OBJECTIVES: To evaluate the tonsil T cell immune response to HPV and compare this to the frequency of detectable virus at this site. STUDY DESIGN: A cross-sectional study of cancer-free adults undergoing routine tonsillectomy. METHODS: Mucosal immune responses to recombinant HPV16 L2E6E7 and HPV6 L2E7 antigens were measured by tonsillar T-lymphocyte proliferation assay in 13 subjects. HPV deoxyribonucleic acid (DNA) was assessed by PCR and reverse line-blot hybridization in an expanded population of 44 subjects. RESULTS: Proliferative T-cell responses to HPV16 and HPV6 were identified in all patients. The presence of a CD45RO+ T cell population responsive to HPV6 L2E7 was confirmed in three of six subjects tested. There were no CD45RO+ responses to HPV16 L2E6E7 and no evidence of current or latent HPV infection of the tonsil. CONCLUSIONS: T cell memory to human papillomavirus can be identified in tonsil tissue from an adult population in the absence of concurrent HPV infection. How novel HPV vaccines might augment this preexisting cell-mediated immunity is an essential area for investigation.


Assuntos
Papillomavirus Humano 16/imunologia , Papillomavirus Humano 6/imunologia , Tonsila Palatina/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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