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1.
Artigo em Inglês | MEDLINE | ID: mdl-28784678

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) resistant to decolonization agents such as mupirocin and chlorhexidine increases the need for development of alternative decolonization molecules. The absence of reported severe adverse reactions and bacterial resistance to polyhexanide makes it an excellent choice as a topical antiseptic. In the present study, we evaluated the in vitro and in vivo capacity to generate strains with reduced polyhexanide susceptibility and cross-resistance with chlorhexidine and/or antibiotics currently used in clinic. Here we report the in vitro emergence of reduced susceptibility to polyhexanide by prolonged stepwise exposure to low concentrations in broth culture. Reduced susceptibility to polyhexanide was associated with genomic changes in the mprF and purR genes and with concomitant decreased susceptibility to daptomycin and other cell wall-active antibiotics. However, the in vitro emergence of reduced susceptibility to polyhexanide did not result in cross-resistance to chlorhexidine. During in vivo polyhexanide clinical decolonization treatment, neither reduced polyhexanide susceptibility nor chlorhexidine cross-resistance was observed. Together, these observations suggest that polyhexanide could be used safely for decolonization of carriers of chlorhexidine-resistant S. aureus strains; they also highlight the need for careful use of polyhexanide at low antiseptic concentrations.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos Locais/farmacologia , Biguanidas/farmacologia , Farmacorresistência Bacteriana/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Aminoaciltransferases/genética , Proteínas de Bactérias/genética , Parede Celular/efeitos dos fármacos , Clorexidina/farmacologia , Daptomicina/farmacologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Proteínas Repressoras/genética , Infecções Estafilocócicas/tratamento farmacológico
2.
BMC Cancer ; 17(1): 163, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28249598

RESUMO

BACKGROUND: Docetaxel based therapy is one of the first line chemotherapeutic agents for the treatment of metastatic castrate-resistant prostate cancer. However, one of the major obstacles in the treatment of these patients is docetaxel-resistance. Defining the mechanisms of resistance so as to inform subsequent treatment options and combinations represents a challenge for clinicians and scientists. Previous work by our group has shown complex changes in pro and anti-apoptotic proteins in the development of resistance to docetaxel. Targeting these changes individually does not significantly impact on the resistant phenotype but understanding the central signalling pathways and transcription factors (TFs) which control these could represent a more appropriate therapeutic targeting approach. METHODS: Using a number of docetaxel-resistant sublines of PC-3 cells, we have undertaken a transcriptomic analysis by expression microarray using the Affymetrix Human Gene 1.0 ST Array and in conjunction with bioinformatic analyses undertook to predict dysregulated TFs in docetaxel resistant prostate cancer. The clinical significance of this prediction was ascertained by performing immunohistochemical (IHC) analysis of an identified TF (SRF) in the metastatic sites from men who died of advanced CRPC. Investigation of the functional role of SRF was examined by manipulating SRF using SiRNA in a docetaxel-resistant PC-3 cell line model. RESULTS: The transcription factors identified include serum response factor (SRF), nuclear factor kappa-B (NFκB), heat shock factor protein 1 (HSF1), testicular receptor 2 & 4 (TR2 &4), vitamin-D and retinoid x receptor (VDR-RXR) and oestrogen-receptor 1 (ESR1), which are predicted to be responsible for the differential gene expression observed in docetaxel-resistance. IHC analysis to quantify nuclear expression of the identified TF SRF correlates with both survival from date of bone metastasis (p = 0.003), survival from androgen independence (p = 0.00002), and overall survival from prostate cancer (p = 0.0044). Functional knockdown of SRF by siRNA demonstrated a reversal of apoptotic resistance to docetaxel treatment in the docetaxel-resistant PC-3 cell line model. CONCLUSIONS: Our results suggest that SRF could aid in treatment stratification of prostate cancer, and may also represent a therapeutic target in the treatment of men afflicted with advanced prostate cancer.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Neoplasias da Próstata/genética , Fator de Resposta Sérica/genética , Neoplasias Ósseas/genética , Neoplasias Ósseas/secundário , Linhagem Celular Tumoral , Docetaxel , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Prognóstico , Neoplasias da Próstata/metabolismo , Fator de Resposta Sérica/metabolismo , Análise de Sobrevida , Taxoides/farmacologia , Fatores de Transcrição/genética , Ativação Transcricional
4.
J Antimicrob Chemother ; 71(7): 1841-4, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27121399

RESUMO

OBJECTIVES: Tert-butyl benzoquinone (TBBQ) is the oxidation product of tert-butyl hydroquinone (TBHQ), an antimicrobial food additive with >40 years of safe use. TBBQ displays potent activity against Staphylococcus aureus biofilms in vitro. Here, we report on studies to further explore the action of TBBQ on staphylococcal biofilms, and provide a preliminary preclinical assessment of its potential for use as a topical treatment for staphylococcal infections involving a biofilm component. METHODS: The antibacterial properties of TBBQ were assessed against staphylococci growing in planktonic culture and as biofilms in the Calgary Biofilm Device. Established assays were employed to measure the effects of TBBQ on biofilm structure and bacterial membranes, and to assess resistance potential. A living-skin equivalent was used to evaluate the effects of TBBQ on human skin. RESULTS: TBBQ eradicated biofilms of S. aureus and other staphylococcal species at concentrations ≤64 mg/L. In contrast to other redox-active agents exhibiting activity against biofilms, TBBQ did not cause substantial destructuring of the biofilm matrix; instead, the antibiofilm activity of the compound was attributed to its ability to kill slow- and non-growing cells via membrane perturbation. TBBQ acted synergistically with gentamicin, did not damage a living-skin equivalent following topical application and exhibited low resistance potential. CONCLUSIONS: The ability of TBBQ to eradicate biofilms appears to result from its ability to kill bacteria regardless of growth state. Preliminary evaluation suggests that TBBQ represents a promising candidate for development as a topical antibiofilm agent.


Assuntos
Antibacterianos/metabolismo , Benzoquinonas/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Humanos , Viabilidade Microbiana/efeitos dos fármacos , Pele/microbiologia
5.
Clin Radiol ; 71(9): 863-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27345612

RESUMO

AIM: To assess if diffusion-weighted imaging (DWI) alone could be used for follow-up of neuroendocrine hepatic metastases. MATERIAL AND METHODS: This was a retrospective study, approved by the institutional review board. Twenty-two patients with neuroendocrine liver metastases who had undergone more than one liver magnetic resonance imaging (MRI) examination, (including DWI and using hepatocyte-specific contrast medium) were evaluated. Up to five metastases were measured at baseline and at each subsequent examination. The reference standard measurement was performed on the hepatocyte phase by one reader. Three independent readers separately measured the same lesions on DWI sequences alone, blinded to other sequences, and recorded the presence of any new lesions. RESULTS: The longest diameters of 317 liver metastases (91 on 22 baseline examinations and a further 226 measurements on follow-up) were measured on the reference standard by one reader and on three b-values by three other readers. The mean difference between DWI measurements and the reference standard measurement was between 0.01-0.08 cm over the nine reader/b-value combinations. Based on the width of the Bland and Altman interval containing approximately 95% of the differences between the reader observation and the mean of reference standard and DWI measurement, the narrowest interval over the nine reader/b-value combinations was -0.6 to +0.7 cm and the widest was -0.9 to 1 cm. In the evaluation of overall response using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria, the weighted kappa statistic was between 0.49 and 0.86, indicating moderate-to-good agreement between the reference standard and DWI. CONCLUSION: The visualisation and measurement of hepatic metastases using DWI alone are within acceptable limits for clinical use, allowing the use of this rapid technique to restage hepatic disease in patients with neuroendocrine metastases.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/secundário , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
J Antimicrob Chemother ; 70(2): 479-88, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25368206

RESUMO

OBJECTIVES: To investigate the antistaphylococcal/antibiofilm activity and mode of action (MOA) of a panel of redox-active (RA) compounds with a history of human use and to provide a preliminary preclinical assessment of their potential for topical treatment of staphylococcal infections, including those involving a biofilm component. METHODS: Antistaphylococcal activity was evaluated by broth microdilution and by time-kill studies with growing and slow- or non-growing cells. The antibiofilm activity of RA compounds, alone and in combination with established antibacterial agents, was assessed using the Calgary Biofilm Device. Established assays were used to examine the membrane-perturbing effects of RA compounds, to measure penetration into biofilms and physical disruption of biofilms and to assess resistance potential. A living skin equivalent model was used to assess the effects of RA compounds on human skin. RESULTS: All 15 RA compounds tested displayed antistaphylococcal activity against planktonic cultures (MIC 0.25-128 mg/L) and 7 eradicated staphylococcal biofilms (minimum biofilm eradication concentration 4-256 mg/L). The MOA of all compounds involved perturbation of the bacterial membrane, whilst selected compounds with antibiofilm activity caused destructuring of the biofilm matrix. The two most promising agents [celastrol and nordihydroguaiaretic acid (NDGA)] in respect of antibacterial potency and selective toxicity against bacterial membranes acted synergistically with gentamicin against biofilms, did not damage artificial skin following topical application and exhibited low resistance potential. CONCLUSIONS: In contrast to established antibacterial drugs, some RA compounds are capable of eradicating staphylococcal biofilms. Of these, celastrol and NDGA represent particularly attractive candidates for development as topical antistaphylococcal biofilm treatments.


Assuntos
Antibacterianos/farmacologia , Oxirredução/efeitos dos fármacos , Staphylococcus/efeitos dos fármacos , Staphylococcus/fisiologia , Antibacterianos/administração & dosagem , Anti-Infecciosos Locais/administração & dosagem , Anti-Infecciosos Locais/farmacologia , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Mutação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/fisiologia
7.
Clin Exp Immunol ; 179(3): 477-84, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25204207

RESUMO

Infection and inflammation can be antecedents of neonatal encephalopathy (NE) and increase the risk of neurological sequelae. Activated protein C (APC) has anti-coagulant and anti-inflammatory effects and provides neuroprotection in brain and spinal cord injury. We examined neutrophil and monocyte responses to lipopolysaccharide (LPS) in infants with NE compared with healthy adult and neonatal controls, and also studied the effect of APC. Whole blood was incubated with LPS and APC and Toll-like receptor (TLR)-4 (LPS recognition), CD11b expression (activation) and intracellular reactive oxygen intermediate (ROI; function) release from neutrophils and monocytes was examined by flow cytometry serially from days 1 to 7. We found a significant increase in neutrophil ROI in infants with NE on day 3 following LPS compared to neonatal controls and this augmented response was reduced significantly by APC. Neutrophil and monocyte CD11b expression was increased significantly on day 1 in infants with NE compared to neonatal controls. LPS-induced neutrophil TLR-4 expression was increased significantly in infants with NE on days 3 and 7 and was reduced by APC. LPS-induced monocyte TLR-4 was increased significantly in infants with NE on day 7. Neutrophil and monocyte activation and production of ROIs may mediate tissue damage in infants with NE. APC modified LPS responses in infants with NE. APC may reduce the inflammatory responses in NE and may ameliorate multi-organ dysfunction. Further study of the immunomodulatory effects of protein C may be warranted using mutant forms with decreased bleeding potential.


Assuntos
Anticoagulantes/farmacologia , Encéfalo/efeitos dos fármacos , Inflamação/tratamento farmacológico , Deficiência Intelectual Ligada ao Cromossomo X/tratamento farmacológico , Monócitos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Proteína C/farmacologia , Adulto , Encéfalo/patologia , Antígeno CD11b/genética , Antígeno CD11b/metabolismo , Células Cultivadas , Feminino , Humanos , Recém-Nascido , Inflamação/imunologia , Lipopolissacarídeos/imunologia , Masculino , Deficiência Intelectual Ligada ao Cromossomo X/imunologia , Monócitos/imunologia , Fármacos Neuroprotetores , Neutrófilos/imunologia , Espécies Reativas de Oxigênio/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Regulação para Cima/efeitos dos fármacos , Adulto Jovem
8.
Med Teach ; 37(6): 585-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25155281

RESUMO

BACKGROUND: There are a number of approaches to teaching high-risk clinical skills, such as a large bore chest drain insertion, although effectiveness is limited and realism is only achieved at great expense. Summary of work: In response to a training needs' analysis of practitioners in remote and rural areas in Scotland, training in chest drains was identified as an urgent priority need. Subsequently, the Clinical Skills Managed Educational Network (CSMEN) developed an evidence-based multi-professional clinical skills pack. This e-learning resource encompasses all aspects of chest drain management, both pre and in-hospital. The pack and an interactive workshop is used to deliver 'blended' chest drain training on a mobile clinical skills unit. Evaluation confirms that the chest drain training is a valuable resource and has been widely used to deliver skills training in remote and rural areas. Feedback from all professional groups is positive. CONCLUSIONS: Developing shared national resources, with standardised workshops taught in local contexts via a mobile skills unit is one approach to the challenges associated with delivering high-risk clinical skills education.


Assuntos
Cateterismo/métodos , Tubos Torácicos , Serviços de Saúde Rural , Treinamento por Simulação/métodos , Competência Clínica , Medicina Baseada em Evidências , Humanos , Avaliação de Programas e Projetos de Saúde , Escócia
9.
Br J Cancer ; 111(6): 1241-8, 2014 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-25117820

RESUMO

BACKGROUND: Bevacizumab has broad anti-tumour activity, but substantial risk of hypertension. No reliable markers are available for predicting bevacizumab-induced hypertension. METHODS: A genome-wide association study (GWAS) was performed in the phase III bevacizumab-based adjuvant breast cancer trial, ECOG-5103, to evaluate for an association between genotypes and hypertension. GWAS was conducted in those who had experienced systolic blood pressure (SBP) >160 mm Hg during therapy using binary analysis and a cumulative dose model for the total exposure of bevacizumab. Common toxicity criteria (CTC) grade 3-5 hypertension was also assessed. Candidate SNP validation was performed in the randomised phase III trial, ECOG-2100. RESULTS: When using the phenotype of SBP>160 mm Hg, the most significant association in SV2C (rs6453204) approached and met genome-wide significance in the binary model (P=6.0 × 10(-8); OR=3.3) and in the cumulative dose model (P=4.7 × 10(-8); HR=2.2), respectively. Similar associations with rs6453204 were seen for CTC grade 3-5 hypertension but did not meet genome-wide significance. Validation study from ECOG-2100 demonstrated a statistically significant association between this SNP and grade 3/4 hypertension using the binary model (P-value=0.037; OR=2.4). CONCLUSIONS: A genetic variant in SV2C predicted clinically relevant bevacizumab-induced hypertension in two independent, randomised phase III trials.


Assuntos
Inibidores da Angiogênese/efeitos adversos , Anticorpos Monoclonais Humanizados/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Hipertensão/induzido quimicamente , Hipertensão/genética , Glicoproteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Bevacizumab , Biomarcadores , Pressão Sanguínea , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único
10.
Psychol Med ; 44(7): 1553-66, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23985155

RESUMO

BACKGROUND: Central nervous system (CNS) dysfunction is a prominent feature of the functional gastrointestinal (GI) disorder, irritable bowel syndrome (IBS). However, the neurobiological and cognitive consequences of key pathophysiological features of IBS, such as stress-induced changes in hypothalamic-pituitary-adrenal (HPA)-axis functioning, is unknown. Our aim was to determine whether IBS is associated with cognitive impairment, independently of psychiatric co-morbidity, and whether cognitive performance is related to HPA-axis function. METHOD: A cross-sectional sample of 39 patients with IBS, a disease control group of 18 patients with Crohn's disease (CD) in clinical remission and 40 healthy age- and IQ-matched control participants were assessed using the Paired Associates Learning (PAL), Intra-Extra Dimensional Set Shift (IED) and Spatial Working Memory (SWM) tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and a computerized Stroop test. HPA-axis function was determined by measuring the cortisol awakening response (CAR). RESULTS: IBS patients exhibited a subtle visuospatial memory deficit at the PAL six- pattern stage (p = 0.03), which remained after psychiatric co-morbidity was controlled for (p = 0.04). Morning cortisol levels were lower in IBS (p = 0.04) and significantly associated with visuospatial memory performance within IBS only (p = 0.02). CONCLUSIONS: For the first time, altered cognitive function on a hippocampal-mediated test of visuospatial memory, which was related to cortisol levels and independent of psychiatric co-morbidity, has been identified in IBS. Visuospatial memory impairment may be a common, but currently neglected, component of IBS. Further elucidation of the nature of this impairment may lead to a greater understanding of the underlying pathophysiology of IBS, and may provide novel therapeutic approaches.


Assuntos
Síndrome do Intestino Irritável/psicologia , Transtornos da Memória/etiologia , Memória Espacial/fisiologia , Estresse Psicológico/complicações , Adulto , Transtornos Cognitivos/etiologia , Doença de Crohn/complicações , Doença de Crohn/psicologia , Feminino , Humanos , Síndrome do Intestino Irritável/complicações , Masculino
11.
Clin Radiol ; 69(12): 1219-27, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25308238

RESUMO

AIMS: To study the differences in the imaging features of spread from the three cancer cell lines, namely epithelial, sarcomatoid, and lymphoid, resulting in peritoneal carcinomatosis, peritoneal sarcomatosis, and peritoneal lymphomatosis, respectively. MATERIALS AND METHODS: In this institutional review board-approved Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study, an electronic radiology database was searched to identify patients with peritoneal tumour spread who underwent CT imaging at Dana-Farber Cancer Institute, a tertiary cancer institution, between January 2011 and December 2012. Out of 1214 patients with possible peritoneal tumour spread on the radiology reports, 122 patients were included with histopathologically confirmed peritoneal disease (50 randomly selected patients with peritoneal carcinomatosis and sarcomatosis each, and all 22 patients with lymphomatosis). Two blinded, fellowship-trained radiologists in consensus reviewed the CT images in random order and recorded the imaging findings of peritoneal tumour spread. The statistical analysis was performed in two steps: the first comparing incidence of various features in each group and the second step was a pairwise analysis between each cohort. RESULTS: Peritoneal carcinomatosis more frequently had ascites, peritoneal thickening, and omental cake (all p ≤ 0.001). Measurable nodules were less common in peritoneal carcinomatosis (p < 0.001), and when present, were ill-defined and had an irregular outline (p ≤ 0.002). Peritoneal sarcomatosis more often had discrete nodules that were well defined and had a smooth outline and less frequently had ascites, peritoneal thickening, omental caking, serosal implants, and lymphadenopathy (all p ≤ 0.005). Peritoneal lymphomatosis frequently involved the omentum and mesentery, and often had associated lymphadenopathy and splenomegaly (all p ≤ 0.002). CONCLUSION: Peritoneal carcinomatosis, sarcomatosis, and lymphomatosis have distinctive patterns on imaging, which can help the radiologists to differentiate between them.


Assuntos
Carcinoma/diagnóstico por imagem , Linfoma/diagnóstico por imagem , Neoplasias Peritoneais/diagnóstico por imagem , Sarcoma/diagnóstico por imagem , Centros de Atenção Terciária , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Peritônio/diagnóstico por imagem , Estudos Retrospectivos
12.
Br J Cancer ; 108(2): 319-26, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23322198

RESUMO

BACKGROUND: Sunitinib (Su), a tyrosine kinase inhibitor of VEGFR, is effective at producing tumour response in clear cell renal cell carcinoma (cRCC), but resistance to therapy is inevitable. As COX-2 is a known mediator of tumour growth, we explored the potential benefit of COX-2 inhibition in combination with VEGFR inhibition in attempts at delaying tumour progression on Su. METHODS: COX-2 expression was compared with areas of hypoxia in tumours that progressed on Su vs untreated tumours. Mice bearing human cRCC xenografts were treated with Su and the COX-2 inhibitor, celecoxib, and the effects on tumour growth were assessed. Sequential vs concurrent regimens were compared. RESULTS: COX-2 expression was increased in cRCC xenografts in areas of tumour hypoxia. The combination of Su and celecoxib achieved longer times to tumour progression compared to treatment with either agent alone or to untreated control animals in four models. This effect was seen with concurrent but not with sequential therapy. CONCLUSION: COX-2 inhibition can extend the effectiveness of VEGFR inhibition. This effect is dependent on the timing of therapy. Clinical trials combining Su and COX-2 inhibitors should be considered as a means delaying time to progression on sunitinib in patients with metastatic cRCC.


Assuntos
Carcinoma de Células Renais/tratamento farmacológico , Ciclo-Oxigenase 2/metabolismo , Indóis/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Pirazóis/uso terapêutico , Pirróis/uso terapêutico , Sulfonamidas/uso terapêutico , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Celecoxib , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Feminino , Humanos , Indóis/administração & dosagem , Indóis/farmacologia , Camundongos , Pirazóis/farmacologia , Pirróis/administração & dosagem , Pirróis/farmacologia , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Sulfonamidas/farmacologia , Sunitinibe , Ensaios Antitumorais Modelo de Xenoenxerto
13.
J Antimicrob Chemother ; 68(6): 1297-304, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23463211

RESUMO

OBJECTIVES: The antioxidant tert-butylhydroquinone (TBHQ) is a food additive reported to have antibacterial activity, and may therefore have application in the healthcare setting. This study sought to characterize the antibacterial activity and mode of action of TBHQ and its oxidation product, tert-butylbenzoquinone (TBBQ). METHODS: The stability of TBHQ/TBBQ was studied in buffer. Susceptibility testing was performed by broth microdilution, and killing and lytic activity were evaluated by viable counting and culture turbidity measurements. Mode of action studies included following the incorporation of radiolabelled precursors into macromolecules. The effect of TBHQ/TBBQ upon bacterial and mammalian membranes was assessed using the BacLight(TM) assay and by monitoring the haemolysis of equine erythrocytes. RESULTS: TBHQ underwent oxidation in solution to form TBBQ. When oxidation was prevented, TBHQ lacked useful antibacterial activity, indicating that TBBQ is responsible for the antibacterial activity attributed to TBHQ. TBBQ demonstrated activity against Staphylococcus aureus SH1000 (MIC 8 mg/L) and against a panel of clinical S. aureus isolates (MIC90 16 mg/L). TBBQ at 4× MIC caused a >4 log10 drop in cell viability within 6 h without lysis, and eradicated staphylococcal biofilms at 8× MIC. TBBQ did not display preferential inhibition of any single macromolecular synthetic pathway, but caused loss of staphylococcal membrane integrity without haemolytic activity. CONCLUSIONS: TBBQ is responsible for the antibacterial activity previously ascribed to TBHQ. TBBQ prompts loss of staphylococcal membrane integrity; it is rapidly and extensively bactericidal, but is non-lytic. In view of the potent and selective bactericidal activity of TBBQ, this compound warrants further investigation as a candidate antistaphylococcal agent.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Hidroquinonas/farmacologia , Animais , Antibacterianos/química , Proteínas de Bactérias/biossíntese , Biofilmes/efeitos dos fármacos , Meios de Cultura , DNA Bacteriano/biossíntese , Estabilidade de Medicamentos , Eritrócitos/efeitos dos fármacos , Cavalos , Hidroquinonas/química , Testes de Sensibilidade Microbiana , Oxirredução , RNA Bacteriano/biossíntese
14.
Nanotechnology ; 24(33): 335702, 2013 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-23883614

RESUMO

A study to analyse beam damage, image quality and edge contrast in the helium ion microscope (HIM) has been undertaken. The sample investigated was graphene. Raman spectroscopy was used to quantify the disorder that can be introduced into the graphene as a function of helium ion dose. The effects of the dose on both freestanding and supported graphene were compared. These doses were then correlated directly to image quality by imaging graphene flakes at high magnification. It was found that a high magnification image with a good signal to noise ratio will introduce very significant sample damage. A safe imaging dose of the order of 10(13) He(+) cm(-2) was established, with both graphene samples becoming highly defective at doses over 5 × 10(14) He(+) cm(-2).The edge contrast of a freestanding graphene flake imaged in the HIM was then compared with the contrast of the same flake observed in a scanning electron microscope and a transmission electron microscope. Very strong edge sensitivity was observed in the HIM. This enhanced edge sensitivity over the other techniques investigated makes the HIM a powerful nanoscale dimensional metrology tool, with the capability of both fabricating and imaging features with sub-nanometre resolution.

15.
Radiography (Lond) ; 29 Suppl 1: S128-S136, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36907794

RESUMO

INTRODUCTION: Radiotherapy is a major component of cancer care and treatment is delivered almost exclusively by therapeutic radiographers/radiation therapists (RTTs). Numerous government and professional guidance publications have recommended a person-centred approach to healthcare through communication and collaboration between professionals, agencies, and users. With approximately half of patients undergoing radical radiotherapy experiencing some degree of anxiety and distress, RTTs are uniquely placed as frontline cancer professionals to engage with patients regarding their experience. This review seeks to map the available evidence of patient reported views of their experience of being treated by RTTs and any impact, this treatment had on the patient's frame of mind or perception of treatment. METHODS: In line with the principles of the Preferred Reporting Items for Systematic and Meta-Analyses (PRISMA) systematic review methodology, a review of relevant literature was conducted. Electronic databases MEDLINE, PROQUEST, EMBASE and CINAHL were searched. RESULTS: Nine hundred and eighty-eight articles were identified. Twelve papers were included in the final review. CONCLUSION: Increased time with, and continuity of RTTs during treatment has a positive influence on patients' perspectives of RTTs. A positive patient perspective of their engagement with RTTs can be a strong predictor of overall satisfaction in radiotherapy. IMPLICATIONS FOR PRACTICE: RTTs should not underestimate the impact of their supportive role in guiding patients through treatment. A standardised method for integrating patients' experience and engagement with RTTs is lacking. Further RTT led research is required in this area.


Assuntos
Participação do Paciente , Radioterapia (Especialidade) , Humanos , Pacientes , Pessoal Técnico de Saúde , Comunicação
16.
Radiography (Lond) ; 29 Suppl 1: S32-S39, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36889995

RESUMO

INTRODUCTION: Radiotherapy is delivered almost exclusively by therapeutic radiographers/radiation therapist (RTTs). Patient's perspectives of RTTs affect levels of trust and confidence in the profession and can have a significant impact on overall radiotherapy experience. The study reports patients' perspectives of RTTs from their experience of undergoing radiotherapy. Four partner sites collaborated in this research and included Malta, Poland, Portugal, and the UK (lead site). METHODS: A survey was developed to gather information from patients receiving radiotherapy or who had had radiotherapy within the previous 24 months. Participants ranked their responses to 23 statements relating to person-centred care on a 5-point scale of 1 (strongly disagree) to 5 (strongly agree). Mann-Whitney or Kruskal Wallis tests were applied to test differences in responses to 5 key statements for patient characteristics including gender, age group, diagnosis, country, time spent with RTTs and number of fractions remaining at survey completion. RESULTS: Three hundred and forty-seven surveys are included. Patients report a positive perception of RTTs (95.4% agree with 'I feel cared for'). Statistically significant differences in responses were found between gender, diagnosis, country, time spent with RTTs and fractions of radiotherapy remaining. Patients who had more time with RTTs and completed their surveys during radiotherapy had a more positive perception of RTTs. CONCLUSION: This study suggests that sufficient time with RTTs is key to ensuring a positive radiotherapy patient experience. RTTs being attentive, understanding, and informative are most predictive of a positive overall patient experience. Timing of survey completion can influence responses. IMPLICATIONS FOR PRACTICE: RTT education programmes should incorporate training on person-centred care at all levels. Further research into patient experience of RTTs is warranted.


Assuntos
Relações Médico-Paciente , Radioterapia (Especialidade) , Radiologistas , Inquéritos e Questionários , Radioterapia (Especialidade)/estatística & dados numéricos , Radiologistas/normas , Radiologistas/estatística & dados numéricos , Europa (Continente) , Fatores de Tempo , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade
17.
Nat Biomed Eng ; 7(4): 559-575, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36266536

RESUMO

Electrical neurostimulation is effective in the treatment of neurological disorders, but associated recording artefacts generally limit its applications to open-loop stimuli. Real-time and continuous closed-loop control of brain activity can, however, be achieved by pairing concurrent electrical recordings and optogenetics. Here we show that closed-loop optogenetic stimulation with excitatory opsins enables the precise manipulation of neural dynamics in brain slices from transgenic mice and in anaesthetized non-human primates. The approach generates oscillations in quiescent tissue, enhances or suppresses endogenous patterns in active tissue and modulates seizure-like bursts elicited by the convulsant 4-aminopyridine. A nonlinear model of the phase-dependent effects of optical stimulation reproduced the modulation of cycles of local-field potentials associated with seizure oscillations, as evidenced by the systematic changes in the variability and entropy of the phase-space trajectories of seizures, which correlated with changes in their duration and intensity. We also show that closed-loop optogenetic neurostimulation could be delivered using intracortical optrodes incorporating light-emitting diodes. Closed-loop optogenetic approaches may be translatable to therapeutic applications in humans.


Assuntos
Optogenética , Convulsões , Camundongos , Animais , Camundongos Transgênicos , Primatas , Encéfalo
18.
Radiography (Lond) ; 29 Suppl 1: S117-S127, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36959043

RESUMO

INTRODUCTION: The role of the Therapy Radiographer/Radiation Therapist (TR/RTT) is to provide radiotherapy to patients with a cancer diagnosis. This includes, not only administration of treatment, but also management of side-effects and provision of support/care. Despite this role being consistent throughout Europe, there is currently no standardisation of education for TRs/RTTs. The SAFE EUROPE project aims to standardize TR/RTT education to enable 'safe and free exchange' of TRs/RTTs across Europe. Consequently, this study aims to explore patients' perspectives regarding the current skills and competencies of TRs/RTTs. METHODS: From May 2021 to February 2022, semi-structured interviews were conducted with patients who had recently received radiotherapy in the UK, Malta and Portugal. Ethical approval for this study was granted by the NHS Research Ethics Committee with additional local approvals obtained. RESULTS: Forty-eight participants from the UK (n = 18), Portugal (n = 19), and Malta (n = 11) completed interviews. Participants described high satisfaction with TRs'/RTTs' competence and skills in all three countries. The main theme arising from the analysis was the importance of trust building with TRs/RTTs. Six factors were identified as influencing levels of trust: communication; side-effect management; team consistency; relational skills; patient dignity; and competence. A small number of patients reported feeling rushed and not having their physical and emotional needs met by TRs/RTTs. CONCLUSION: This multicentre study demonstrated that patients perceive TRs/RTTs in the UK, Malta and Portugal as highly competent and skilled. Practical recommendations are provided to address identified deficits in practice, which can be addressed through adaptation of TR/RTT education/training and clinical practice. IMPLICATIONS FOR PRACTICE: Recommendations arising from this study are important to ensure that TRs/RTTs have transferable skills that provide consistently high quality care to patients throughout Europe.


Assuntos
Radioterapia (Especialidade) , Humanos , Portugal , Malta , Europa (Continente) , Reino Unido
19.
Antimicrob Agents Chemother ; 56(1): 579-81, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21986827

RESUMO

The genetic basis of tolerance to inhibitors of peptidoglycan biosynthesis in Staphylococcus aureus was investigated by generating tolerant mutants in vitro and characterizing them by comparative genome sequencing. Two independently selected tolerant mutants harbored nonsynonymous mutations in gdpP, a gene encoding a putative membrane-located signaling protein. Insertional inactivation of gdpP also conferred tolerance. Our findings further implicate altered signal transduction as a route to antibiotic tolerance in S. aureus.


Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Glicopeptídeos/farmacologia , Staphylococcus aureus/genética , beta-Lactamas/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , DNA Bacteriano , Inativação Gênica , Testes de Sensibilidade Microbiana , Mutagênese Insercional , Mutação , Estrutura Terciária de Proteína , Transdução de Sinais/genética , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/metabolismo
20.
Ann Oncol ; 23(2): 331-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21821545

RESUMO

BACKGROUND: E2104 was designed to evaluate the safety of two different strategies incorporating bevacizumab into anthracycline-containing adjuvant therapy as a precursor to a definitive randomized phase III trial. PATIENTS AND METHODS: Patients were sequentially assigned to one of two treatment arms. In addition to dose-dense doxorubicin and cyclophosphamide followed by paclitaxel (Taxol) (ddAC→T), all patients received bevacizumab (10 mg/kg every 2 weeks × 26) initiated either concurrently with AC (Arm A: ddBAC→BT→B) or with paclitaxel (Arm B: ddAC→BT→B). The primary end point was incidence of clinically apparent cardiac dysfunction (CHF). RESULTS: Patients enrolled were 226 in number (Arm A 104, Arm B 122). Grade 3 hypertension, thrombosis, proteinuria and hemorrhage were reported for 12, 2, 2 and <1% of patients, respectively. Two patients developed grade 3 or more cerebrovascular ischemia. Three patients in each arm developed CHF. There was no significant difference between arms in the proportion of patients with an absolute decrease in left ventricular ejection fraction of >15% or >10% to below the lower limit of normal post AC or post bevacizumab. CONCLUSIONS: Incorporation of bevacizumab into anthracycline-containing adjuvant therapy does not result in prohibitive cardiac toxicity. The definitive phase III trial (E5103) was activated with systematic and extensive cardiac monitoring to define the true impact of bevacizumab on cardiac function.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Cardiopatias/induzido quimicamente , Adulto , Idoso , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Projetos Piloto
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