Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 192
Filtrar
1.
Support Care Cancer ; 32(7): 424, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864894

RESUMO

PURPOSE: We conducted a systematic review to describe health-related quality of life (HRQOL) in rural cancer survivors (RCS), and compare HRQOL between RCS and urban cancer survivors (UCS). METHOD: We searched Medline, Embase, CINAHL Plus, and PsycINFO for studies with HRQOL in adult cancer survivors living in rural, regional, remote, and urban areas, who had completed definitive primary cancer treatment, without evidence of residual disease. Where available, we used normative and clinically important values to ascribe meaning to HRQOL data. FINDINGS: Fifteen studies (16 papers) were included. Most were from the US (n = 8) and reported on breast cancer survivors (n = 9). Six HRQOL instruments, collecting data across 16 domains, were used. Three instruments were specific to the survivorship phase. Normative and clinical data were available for 12 studies. Compared with normative populations, RCS had clinically worse physical HRQOL (6/12 studies), better social/family (5/7), and functional (3/6) HRQOL, and there were no differences in emotional or/mental HRQOL (9/12). In six studies with rural-urban comparator groups and normative and clinically important data, RCS and UCS had clinically worse physical (3/6 and 2/6, respectively) and better social/family (3/4 and 2/4 studies, respectively) HRQOL than normative populations. Functional HRQOL was better in RCS (2/4 studies) than UCS and normative populations. In 3/6 studies, there were no clinical differences in emotional or/mental HRQOL between RCS, UCS, and normative populations. CONCLUSION: Overall, HRQOL is not clearly better or worse in RCS than UCS. Future research should include different tumor types, rural residents, and survivorship-specific HRQOL instruments.


Assuntos
Sobreviventes de Câncer , Qualidade de Vida , População Rural , População Urbana , Humanos , Sobreviventes de Câncer/psicologia , População Rural/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Neoplasias/psicologia , Neoplasias/terapia
2.
Nature ; 562(7727): 386-390, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30305732

RESUMO

Despite considerable efforts over the past decade, only 34 fast radio bursts-intense bursts of radio emission from beyond our Galaxy-have been reported1,2. Attempts to understand the population as a whole have been hindered by the highly heterogeneous nature of the searches, which have been conducted with telescopes of different sensitivities, at a range of radio frequencies, and in environments corrupted by different levels of radio-frequency interference from human activity. Searches have been further complicated by uncertain burst positions and brightnesses-a consequence of the transient nature of the sources and the poor angular resolution of the detecting instruments. The discovery of repeating bursts from one source3, and its subsequent localization4 to a dwarf galaxy at a distance of 3.7 billion light years, confirmed that the population of fast radio bursts is located at cosmological distances. However, the nature of the emission remains elusive. Here we report a well controlled, wide-field radio survey for these bursts. We found 20, none of which repeated during follow-up observations between 185-1,097 hours after the initial detections. The sample includes both the nearest and the most energetic bursts detected so far. The survey demonstrates that there is a relationship between burst dispersion and brightness and that the high-fluence bursts are the nearby analogues of the more distant events found in higher-sensitivity, narrower-field surveys5.

3.
Methods Enzymol ; 588: 133-153, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28237097

RESUMO

Cancer cells undergoing starvation- and treatment-induced autophagy were found to exhibit reduced intracellular lactate, reduced rates of steady-state lactate excretion and reduced real-time pyruvate-lactate exchange rates, indicating that glycolytic metabolism was altered in autophagic cells. In this chapter, we describe the technical details of the use of 1H-magnetic resonance spectroscopy (MRS) to measure endogenous cellular concentrations of lactate and glucose in autophagic cells and tissues, how to measure the rate of steady-state lactate excretion and glucose uptake by 1H-MRS in autophagic cells, and details of the real-time measurement of [1-13C] pyruvate to lactate exchange in autophagic cells by 13C-MRS-DNP (dynamic nuclear polarization).


Assuntos
Autofagia , Glicólise , Espectroscopia de Ressonância Magnética/métodos , Animais , Isótopos de Carbono/análise , Isótopos de Carbono/metabolismo , Glucose/análise , Glucose/metabolismo , Humanos , Ácido Láctico/análise , Ácido Láctico/metabolismo , Ácido Pirúvico/análise , Ácido Pirúvico/metabolismo
4.
NMR Biomed ; 29(10): 1420-6, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27514007

RESUMO

(1) H MRS measurements of lactate are often confounded by overlapping lipid signals. Double-quantum (DQ) filtering eliminates lipid signals and permits single-shot measurements, which avoid subtraction artefacts in moving tissues. This study evaluated a single-voxel-localized DQ filtering method qualitatively and quantitatively for measuring lactate concentrations in the presence of lipid, using high-grade brain tumours in which the results could be compared with standard acquisition as a reference. Paired standard acquisition and DQ-filtered (1) H MR spectra were acquired at 3T from patients receiving treatment for glioblastoma, using fLASER (localization by adiabatic selective refocusing using frequency offset corrected inversion pulses) single-voxel localization. Data were acquired from 2 × 2 × 2 cm(3) voxels, with a repetition time of 1 s and 128 averages (standard acquisition) or 256 averages (DQ-filtered acquisition), requiring 2.15 and 4.3 min respectively. Of 37 evaluated data pairs, 20 cases (54%) had measureable lactate (fitted Cramér-Rao lower bounds ≤ 20%) in either the DQ-filtered or the standard acquisition spectra. The measured DQ-filtered lactate signal was consistently downfield of lipid (1.33 ± 0.03 ppm vs 1.22 ± 0.08 ppm; p = 0.002), showing that it was not caused by lipid breakthrough, and that it matched the lactate signal seen in standard measurements (1.36 ± 0.02 ppm). In the absence of lipid, similar lactate concentrations were measured by the two methods (mean ratio DQ filtered/standard acquisition = 1.10 ± 0.21). In 7/20 cases with measurable lactate, signal was not measureable in the standard acquisition owing to lipid overlap but was quantified in the DQ-filtered acquisition. Conversely, lactate was undetected in seven DQ-filtered acquisitions but visible using the standard acquisition. In conclusion, the DQ filtering method has proven robust in eliminating lipid and permits uncontaminated measurement of lactate. This is important validation prior to use in tissues outside the brain, which contain large amounts of lipid and which are often susceptible to motion.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Ácido Láctico/metabolismo , Imagem Molecular/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Processamento de Sinais Assistido por Computador , Algoritmos , Humanos , Imageamento por Ressonância Magnética/métodos , Gradação de Tumores , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Lab Anim ; 50(2): 108-18, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26162377

RESUMO

Intestinal mucositis is a frequent side-effect of chemotherapy treatment. Many oncological research programs aim to identify novel treatments for this distressing condition, and these programs frequently use rat models. Little is known about the presence and progression of pain in these models and how this can best be treated by analgesic therapy. We used a number of behaviour-based methods of pain assessment to determine which tools were best suited for pain identification. Baseline measures for behavioural assessment, rat grimace score and sociability were determined through analysis of continuously recorded video data and an applied social interaction test (n = 16). Mucositis was then induced by intraperitoneal injection of 5-fluorouracil (150 mg/kg) and further behavioural analyses undertaken. An assessment of enrichment interaction was also made by determining the mass of a plastic chew toy gnawed both pre- and post-chemotherapy injection. Behavioural scoring was performed 1, 6, 12, 24 and 48 h after injection, with facial expression being scored at the 12, 24 and 48 h time-points. Sociability testing was performed once during the post-injection period. No significant differences were found in grimace scores between baseline and later daily measures. Behaviours similar to those previously reported post-laparotomy were observed. Writhing, twitching and back-arching behaviours were most evident in rats affected by mucositis and were increased in frequency (respective P values: 0.002, 0.004 and 0.008) 48 h after chemotherapy injection compared with baseline, implying that pain onset occurred around this time-point. Social investigatory behaviour was also increased (P = 0.002) following disease onset. Each day, rats post-5FU injection gnawed a greater percentage of their Nylabone enrichment by weight than the saline-injected control rats (P = 0.046). These data suggest that, of the tools tested, behavioural assessment scoring may find greatest utility in rodent models of intestinal mucositis and should be investigated further.


Assuntos
Bem-Estar do Animal , Expressão Facial , Mucosite/fisiopatologia , Medição da Dor/métodos , Ratos/fisiologia , Comportamento Social , Animais , Fluoruracila/efeitos adversos , Injeções Intraperitoneais , Masculino , Mucosite/induzido quimicamente , Dor/induzido quimicamente , Dor/fisiopatologia , Ratos Sprague-Dawley , Fatores de Tempo
6.
Br J Cancer ; 112(7): 1206-14, 2015 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-25742484

RESUMO

BACKGROUND: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management. METHODS: Here we use human head and neck squamous cell carcinoma (HNSCC) models and nuclear magnetic resonance (NMR) spectroscopy to assess the metabolic changes that follow acquired resistance to EGFR tyrosine kinase inhibitors (TKIs), and which could serve as potential metabolic biomarkers of drug resistance. RESULTS: Comparison of NMR metabolite profiles obtained from control (CAL(S)) and EGFR TKI-resistant (CAL(R)) cells grown as 2D monolayers, 3D spheroids or xenograft tumours in athymic mice revealed a number of differences between the sensitive and drug-resistant models. In particular, we observed elevated levels of glycerophosphocholine (GPC) in CAL(R) relative to CAL(S) monolayers, spheroids and tumours, independent of the growth rate or environment. In addition, there was an increase in alanine, aspartate and creatine+phosphocreatine in resistant spheroids and xenografts, and increased levels of lactate, branched-chain amino acids and a fall in phosphoethanolamine only in xenografts. The xenograft lactate build-up was associated with an increased expression of the glucose transporter GLUT-1, whereas the rise in GPC was attributed to inhibition of GPC phosphodiesterase. Reduced glycerophosphocholine (GPC) and phosphocholine were observed in a second HNSCC model probably indicative of a different drug resistance mechanism. CONCLUSIONS: Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models. These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Receptores ErbB/antagonistas & inibidores , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Humanos , Camundongos , Camundongos Nus , Carcinoma de Células Escamosas de Cabeça e Pescoço , Ensaios Antitumorais Modelo de Xenoenxerto
7.
NMR Biomed ; 28(3): 338-43, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25586623

RESUMO

Lactate is a product of glucose metabolism. In tumour tissues, which exhibit enhanced glycolytic metabolism, lactate signals may be elevated, making lactate a potential useful tumour biomarker. Methods of lactate quantitation are complicated because of overlap between the lactate methyl doublet CH3 resonance and a lipid resonance at 1.3 ppm. This study presents the use of a selective homonuclear multiple quantum coherence transfer sequence (SelMQC-CSI), at 1.5 T, to better quantify lactate in the presence of lipids. Work performed on phantoms showed good lactate detection (49%) and lipid suppression (98%) efficiencies. To evaluate the method in the brain, the sequence was tested on a group of 23 patients with treated brain tumours, either glioma (N=20) or secondary metastases in the brain (N=3). Here it was proved to be of use in determining lactate concentrations in vivo. Lactate was clearly seen in SelMQC spectra of glioma, even in the presence of lipids, with high grade glioma (7.3 ± 1.9 mM, mean ± standard deviation) having higher concentrations than low grade glioma (1.9 ± 1.5 mM, p=0.048). Lactate was not seen in secondary metastases in the brain. SelMQC-CSI is shown to be a useful technique for measuring lactate in tumours whose signals are otherwise contaminated by lipid.


Assuntos
Neoplasias Encefálicas/metabolismo , Ácido Láctico/análise , Imagens de Fantasmas , Teoria Quântica , Encéfalo/metabolismo , Encéfalo/patologia , Humanos , Ácido Láctico/metabolismo , Lipídeos/química , Imageamento por Ressonância Magnética , Metaboloma
8.
Phys Med Biol ; 60(4): 1681-96, 2015 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-25633183

RESUMO

A commercial active breathing coordinator (ABC) device, employed to hold respiration at a specific level for a predefined duration, was successfully adapted for magnetic resonance imaging (MRI) use for the first time. Potential effects of the necessary modifications were assessed and taken into account. Automatic MR acquisition during ABC breath holding was achieved. The feasibility of MR-ABC thoracic and abdominal examinations together with the advantages of imaging in repeated ABC-controlled breath holds were demonstrated on healthy volunteers. Five lung cancer patients were imaged under MR-ABC, visually confirming the very good intra-session reproducibility of organ position in images acquired with the same patient positioning as used for computed tomography (CT). Using identical ABC settings, good MR-CT inter-modality registration was achieved. This demonstrates the value of ABC, since application of T1, T2 and diffusion weighted MR sequences provides a wider range of contrast mechanisms and additional diagnostic information compared to CT, thus improving radiotherapy treatment planning and assessment.


Assuntos
Suspensão da Respiração , Imageamento por Ressonância Magnética/métodos , Técnicas de Imagem de Sincronização Respiratória/métodos , Humanos , Imageamento por Ressonância Magnética/instrumentação , Masculino , Posicionamento do Paciente , Técnicas de Imagem de Sincronização Respiratória/instrumentação , Transdutores
9.
Leukemia ; 29(1): 107-14, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24787488

RESUMO

Monoclonal antibodies (MAbs) form a central part of chronic lymphocytic leukaemia (CLL) treatment. We therefore evaluated whether complement defects in CLL patients reduced the induction of complement-dependent cytotoxicity (CDC) by using anti-CD20 MAbs rituximab (RTX) and ofatumumab (OFA). Ofatumumab elicited higher CDC levels than RTX in all CLL samples examined, particularly in poor prognosis cohorts (11q- and 17p-). Serum sample analyses revealed that 38.1% of patients were deficient in one or more complement components, correlating with reduced CDC responses. Although a proportion of patients with deficient complement levels initially induced high levels of CDC, on secondary challenge CDC activity in sera was significantly reduced, compared with that in normal human serum (NHS; P<0.01; n=52). In addition, a high CLL cell number contributed to rapid complement exhaustion. Supplementing CLL serum with NHS or individual complement components, particularly C2, restored CDC on secondary challenge to NHS levels (P<0.0001; n=9). In vivo studies revealed that complement components were exhausted in CLL patient sera post RTX treatment, correlating with an inability to elicit CDC. Supplementing MAb treatment with fresh-frozen plasma may therefore maintain CDC levels in CLL patients with a complement deficiency or high white blood cell count. This study has important implications for CLL patients receiving anti-CD20 MAb therapy.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígenos CD20/imunologia , Proteínas do Sistema Complemento/deficiência , Leucemia Linfocítica Crônica de Células B/terapia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados , Células Cultivadas , Humanos , Leucemia Linfocítica Crônica de Células B/sangue
10.
J R Coll Physicians Edinb ; 44(1): 36-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24995446

RESUMO

The full blood count (FBC) is perhaps the single most common investigation performed in medical patients. It has the potential, when interpreted carefully and in relation to the clinical history, to provide very useful information to assist in diagnosis and management. Clinicians are often alerted to the presence of a primary haematological disorder by abnormalities in the FBC. For the purpose of this review these diseases will not be discussed in detail but the reader will be alerted to pointers which might indicate primary blood disorders throughout the text. The haematology laboratory in large teaching hospitals will often provide up to 1,500 automated FBC analyses each day. These are individually checked for 'flags' provided by the analyser which indicate values outside the normal range. It is clearly essential that clinical information is provided with the request as this will influence how the result is handled by scientific and medical staff. Furthermore, significant abnormalities will generate a blood film request and the report will be most useful when interpreted in light of the patient's working diagnosis. In cases where a diagnosis is not yet known, even brief information on presentation, for example 'collapse with hypotension', 'fever on return to UK', 'weight loss and anorexia', can all be important and help the lab provide clinicians with guidance. This short review aims to provide physicians with a workable guide to the interpretation of some of the commoner findings in the full blood count. Some of these will be very familiar to you but some will not. This review is not meant to be exhaustive as the rare minutiae will obscure the essential core material. Your haematology colleagues are always happy to help and available for assistance in difficult or problematic cases. I have not specified normal ranges in relation to each entity as these will be defined by your local laboratory.


Assuntos
Anemia/diagnóstico , Contagem de Células Sanguíneas , Anemia/sangue , Diagnóstico Diferencial , Humanos , Policitemia/sangue , Policitemia/diagnóstico , Valores de Referência
11.
Br J Cancer ; 111(2): 375-85, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24892448

RESUMO

BACKGROUND: Dichloroacetate (DCA) has been found to have antitumour properties. METHODS: We investigated the cellular and metabolic responses to DCA treatment and recovery in human colorectal (HT29, HCT116 WT and HCT116 Bax-ko), prostate carcinoma cells (PC3) and HT29 xenografts by flow cytometry, western blotting, electron microscopy, (1)H and hyperpolarised (13)C-magnetic resonance spectroscopy. RESULTS: Increased expression of the autophagy markers LC3B II was observed following DCA treatment both in vitro and in vivo. We observed increased production of reactive oxygen species (ROS) and mTOR inhibition (decreased pS6 ribosomal protein and p4E-BP1 expression) as well as increased expression of MCT1 following DCA treatment. Steady-state lactate excretion and the apparent hyperpolarised [1-(13)C] pyruvate-to-lactate exchange rate (k(PL)) were decreased in DCA-treated cells, along with increased NAD(+)/NADH ratios and NAD(+). Steady-state lactate excretion and k(PL) returned to, or exceeded, control levels in cells recovered from DCA treatment, accompanied by increased NAD(+) and NADH. Reduced k(PL) with DCA treatment was found in HT29 tumour xenografts in vivo. CONCLUSIONS: DCA induces autophagy in cancer cells accompanied by ROS production and mTOR inhibition, reduced lactate excretion, reduced k(PL) and increased NAD(+)/NADH ratio. The observed cellular and metabolic changes recover on cessation of treatment.


Assuntos
Autofagia/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Ácido Dicloroacético/farmacologia , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Feminino , Células HCT116 , Células HT29 , Humanos , Ácido Láctico/metabolismo , Camundongos , Camundongos Nus , Microscopia Eletrônica , NAD/metabolismo , Distribuição Aleatória , Espécies Reativas de Oxigênio/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores
12.
Br J Radiol ; 86(1030): 20130281, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23995873

RESUMO

OBJECTIVE: To determine the prognostic value of pre-treatment apparent diffusion coefficient (ADC) of colorectal liver metastases in predicting disease response, progression-free survival (PFS) and overall survival (OS). METHODS: We retrospectively reviewed 102 patients who underwent pre-treatment diffusion-weighted MRI using a breath-hold (b=0, 150, 500) or a free-breathing (b=0, 50, 100, 250, 500, 750) technique. The mean ADC (b=0-500) and mean flow-insensitive ADC (ADChigh) values (breath-hold: b=150 and 500; free-breathing: b=100 and 500) of up to three hepatic lesions were evaluated in each patient. Clinical and laboratory parameters were recorded. Tumour response was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) criteria at 12 weeks after treatment. Associations between tumour response, ADC values and clinical/laboratory parameters were examined by one-way analysis of variance. The relationship of ADC with PFS and OS was determined by Kaplan-Meier analysis. RESULTS: 62 patients responded to chemotherapy at 12 weeks. The pre-treatment mean ADC and mean ADChigh were higher in the non-responding group than in the responding group (1.55 vs 1.36, p=0.033; 1.40 vs 1.16, p=0.024). However, the PFS and OS of the two groups of patients stratified by the median of mean ADC values or threshold derived by receiver operating characteristic analysis were not statistically significant. By multivariate Cox regression analysis, patients with ≤2 metastases and response to chemotherapy showed better PFS; white cell count ≤10 and surgical treatment were associated with better OS. CONCLUSION: Colorectal liver metastasis with higher pre-treatment mean ADC and mean ADChigh was associated with poorer response to chemotherapy. However, ADC and ADChigh values did not predict the patient outcome in this study cohort. ADVANCES IN KNOWLEDGE: High mean ADC values of colorectal liver metastases on pre-treatment diffusion-weighted MRI is associated with poorer response to chemotherapy.


Assuntos
Neoplasias Colorretais/patologia , Imagem de Difusão por Ressonância Magnética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Imagem de Difusão por Ressonância Magnética/métodos , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Estudos Retrospectivos , Análise de Sobrevida
13.
Br J Cancer ; 109(6): 1562-9, 2013 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-23942066

RESUMO

BACKGROUND: Non-invasive imaging biomarkers underpin the development of molecularly targeted anti-cancer drugs. This study evaluates tumour apparent diffusion coefficient (ADC), measured by diffusion-weighted magnetic resonance imaging (DW-MRI), as a biomarker of response to the MEK1/2 inhibitor selumetinib (AZD6244, ARRY-142886) in human tumour xenografts. METHODS: Nude mice bearing human BRAF(V600D) WM266.4 melanoma or BRAF(V600E) Colo205 colon carcinoma xenografts were treated for 4 days with vehicle or selumetinib. DW-MRI was performed before and 2 h after the last dose and excised tumours analysed for levels of phospho-ERK1/2, cleaved caspase 3 (CC3) and necrosis. RESULTS: Selumetinib treatment induced tumour stasis and reduced ERK1/2 phosphorylation in both WM266.4 and Colo205 tumour xenografts. Relative to day 0, mean tumour ADC was unchanged in the control groups but was significantly increased by up to 1.6-fold in selumetinib-treated WM266.4 and Colo205 tumours. Histological analysis revealed a significant increase in necrosis in selumetinib-treated WM266.4 and Colo205 xenografts and CC3 staining in selumetinib-treated Colo205 tumours relative to controls. CONCLUSION: Changes in ADC following treatment with the MEK1/2 inhibitor selumetinib in responsive human tumour xenografts were concomitant with induction of tumour cell death. ADC may provide a useful non-invasive pharmacodynamic biomarker for early clinical assessment of response to selumetinib and other MEK-ERK1/2 signalling-targeted therapies.


Assuntos
Benzimidazóis/farmacologia , Neoplasias do Colo/tratamento farmacológico , Imagem de Difusão por Ressonância Magnética/métodos , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Melanoma/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/enzimologia , Feminino , Humanos , Melanoma/enzimologia , Camundongos , Camundongos Nus , Terapia de Alvo Molecular , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Eur Radiol ; 23(2): 428-34, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23052642

RESUMO

OBJECTIVE: To determine the measurement reproducibility of perfusion fraction f, pseudodiffusion coefficient D and diffusion coefficient D in colorectal liver metastases and normal liver. METHODS: Fourteen patients with known colorectal liver metastases were examined twice using respiratory-triggered echo-planar DW-MRI with eight b values (0 to 900 s/mm(2)) 1 h apart. Regions of interests were drawn around target metastasis and normal liver in each patient to derive ADC (all b values), ADC(high) (b values ≥ 100 s/mm(2)) and intravoxel incoherent motion (IVIM) parameters f, D and D by least squares data fitting. Short-term measurement reproducibility of median ADC, ADC(high), f, D and D values were derived from Bland-Altman analysis. RESULTS: The measurement reproducibility for ADC, ADC(high) and D was worst in colorectal liver metastases (-21 % to +25 %) compared with liver parenchyma (-6 % to +8 %). Poor measurement reproducibility was observed for the perfusion-sensitive parameters of f (-75 % to +241 %) and D (-89 % to +2,120 %) in metastases, and to a lesser extent the f (-24 % to +25 %) and D (-31 % to +59 %) of liver. CONCLUSIONS: Estimates of f and D derived from the widely used least squares IVIM fitting showed poor measurement reproducibility. Efforts should be made to improve the measurement reproducibility of perfusion-sensitive IVIM parameters.


Assuntos
Neoplasias Colorretais/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundário , Adulto , Idoso , Algoritmos , Estudos de Casos e Controles , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Perfusão , Estudos Prospectivos , Padrões de Referência , Reprodutibilidade dos Testes
15.
Eur Radiol ; 23(6): 1537-45, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23242002

RESUMO

OBJECTIVES: To investigate the effect of magnetic field heterogeneity in breast dynamic contrast-enhanced examinations with fat saturation (DCE-FS). METHODS: The magnetic field was mapped over the breasts in ten patients. DCE-FS was undertaken at 1.5 T with fast spoiled gradient echoes and spectrally selective fat saturation. Signal intensity was calculated for T1 values 25-1,200 ms both on and off resonance, and results were verified with a test object. Clinical examinations were evaluated for the predicted effects of field heterogeneity. RESULTS: Magnetic field was found to vary by 3.6 ± 1.2 ppm over the central transaxial slice and 5.1 ± 1.5 over the whole breast volume (mean ± standard deviation). Computer simulations predict a reduction in the dynamic range if field heterogeneity leads to unintended water suppression, and distortion to CA uptake curves due to fat suppression failure (for fat containing pixels). A compromise between dynamic range and fat saturation performance is required. Both water suppression and fat suppression failure are apparent in clinical examinations. CONCLUSION: Magnetic field heterogeneity is likely to reduce the sensitivity of DCE-FS by distorting the CA uptake curves because of fat suppression failure (for fat containing pixels) and by reducing the dynamic range because of unintended water suppression. KEY POINTS: • Magnetic field heterogeneity is significant in breast magnetic resonance. • Contrast-agent uptake curves are distorted by a non-uniform magnetic field. • Radiologist must be aware of possibility of distortion to interpret uptake curves correctly. • Compromise between fat suppression and dynamic range is required.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Mama/patologia , Meios de Contraste/farmacocinética , Tecido Adiposo/patologia , Algoritmos , Simulação por Computador , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Campos Magnéticos , Reprodutibilidade dos Testes , Água/química
16.
Exp Toxicol Pathol ; 65(4): 451-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22459205

RESUMO

Human liver cancer is in part associated with obesity and related metabolic diseases. The present study was undertaken in a mouse model of diet-induced obesity (DIO) and hepatic steatosis, conditions which can be associated with hepatic neoplasia, to determine whether the rates of cell proliferation or hepatocarcinogen bioactivation were altered in ways which could facilitate hepatocarcinogenesis. DIO mice were generated by feeding C57BL/6 (B6) male mice a high-fat diet beginning at 4 weeks of age; age-matched conventional lean (LEAN) B6 mice fed a low fat diet (10% Kcal from fat) were used for comparison. Groups of 28 week old DIO and LEAN mice were dosed with the bioactivation-dependent DNA-reactive hepatocarcinogen 2-acetylaminofluorene (AAF), at 2.24 or 22.4 mg/kg, given by gavage 3 times per week for 31 days, or received no treatment (DIO and LEAN control groups). Compared with the LEAN control group, the DIO control group had a higher mean body weight (16.5 g), higher mean absolute (1.4 g) and mean relative (25.5%) liver weights, higher (394%) liver triglyceride concentrations, and an increased incidence and severity of hepatocellular steatosis at the end of the dosing phase. The DIO control group also had a higher mean hepatocellular replicating fraction (31% increase, determined by proliferating cell nuclear antigen immunohistochemistry). Hepatocarcinogen bioactivation, based on formation of AAF DNA adducts as measured by nucleotide (32)P-postlabeling, was similar in both DIO and LEAN AAF-dosed groups. Thus, hepatocellular proliferation, but not hepatocarcinogen bioactivation, was identified as an alteration in livers of DIO mice which could contribute to their susceptibility to hepatocarcinogenesis.


Assuntos
Proliferação de Células/efeitos dos fármacos , Fígado Gorduroso/fisiopatologia , Hepatócitos/efeitos dos fármacos , Obesidade/complicações , 2-Acetilaminofluoreno/análogos & derivados , 2-Acetilaminofluoreno/toxicidade , Ração Animal , Animais , Carcinógenos/toxicidade , Adutos de DNA/análise , Adutos de DNA/biossíntese , Dieta com Restrição de Gorduras , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/fisiopatologia
17.
J R Coll Physicians Edinb ; 42(4): 317-21, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23240118

RESUMO

We describe a case of a delayed diagnosis of Sezary syndrome in a patient with longstanding generalised pruritus, erythroderma, alopecia and nail dystrophy. We highlight some of the difficulties in diagnosis despite the fact that all patients have a characteristic circulating malignant T-cell lymphocyte in peripheral blood. These cells with cerebriform nuclei should be sought in peripheral blood films and further evaluated using flow cytometry in all patients with an erythrodermatous presentation. We summarise current treatment options although, as with all rare diseases, there are few randomised controlled clinical trials to inform decisions on optimal therapy for each individual patient.


Assuntos
Síndrome de Sézary/diagnóstico , Síndrome de Sézary/tratamento farmacológico , Dermatopatias/diagnóstico , Dermatopatias/tratamento farmacológico , Idoso , Alopecia/diagnóstico , Núcleo Celular/patologia , Dermatite Esfoliativa/diagnóstico , Feminino , Citometria de Fluxo , Humanos , Unhas/patologia , Prurido/diagnóstico , Síndrome de Sézary/sangue , Síndrome de Sézary/patologia , Dermatopatias/sangue , Dermatopatias/patologia , Linfócitos T/metabolismo , Linfócitos T/patologia
19.
Eur Radiol ; 22(12): 2648-53, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22706913

RESUMO

OBJECTIVES: Silicone breast prostheses prove technically challenging when performing diffusion-weighted MR imaging in the breasts. We describe a combined fat and chemical suppression scheme to achieve dual suppression of fat and silicone, thereby improving the quality of diffusion-weighted images in women with breast implants. METHODS: MR imaging was performed at 3.0 and 1.5 T in women with silicone breast implants using short-tau inversion recovery (STIR) fat-suppressed echo-planar (EPI) diffusion-weighted MR imaging (DWI) on its own and combined with the slice-select gradient-reversal (SSGR) technique. Imaging was performed using dedicated breast imaging coils. RESULTS: Complete suppression of the fat and silicone signal was possible at 3.0 T using EPI DWI with STIR and SSGR, evaluated with dedicated breast coils. However, a residual silicone signal was still perceptible at 1.5 T using this combined approach. Nevertheless, a further reduction in silicone signal at 1.5 T could be achieved by employing thinner slice partitions and the addition of the chemical-selective fat-suppression (CHESS) technique. CONCLUSIONS: DWI using combined STIR and SSGR chemical suppression techniques is feasible to eliminate or reduce silicone signal from prosthetic breast implants. KEY POINTS: Breast magnetic resonance imaging (MRI) is frequently needed following breast implants. Unsuppressed signal from silicone creates artefacts on diffusion-weighted MR sequences. Dual fat/chemical suppression can eliminate signal from fat and silicone. STIR with slice selective gradient reversal can suppress fat and silicone signal.


Assuntos
Implantes de Mama , Imagem de Difusão por Ressonância Magnética/métodos , Tecido Adiposo/anatomia & histologia , Adulto , Artefatos , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Imagem Ecoplanar , Feminino , Humanos , Pessoa de Meia-Idade , Silicones/química , Software
20.
Eur Radiol ; 22(7): 1451-64, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22562143

RESUMO

Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. Key Points • Tumour vascular function is key to tumour development and treatment • Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess tumour vascular function • Thus DCE-MRI with pharmacokinetic models can assess novel treatments • Many recent developments are advancing the accuracy of and information from DCE-MRI • Establishing common methodology across multiple centres is challenging and requires accepted guidelines.


Assuntos
Ensaios Clínicos como Assunto/normas , Meios de Contraste/normas , Imageamento por Ressonância Magnética/normas , Neoplasias/patologia , Neovascularização Patológica/patologia , Guias de Prática Clínica como Assunto , Europa (Continente) , Humanos , Neoplasias/irrigação sanguínea , Padrões de Referência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA