RESUMEN
Motivation: Imaging demonstrates that preclinical and human tumors are heterogeneous, i.e. a single tumor can exhibit multiple regions that behave differently during both development and also in response to treatment. The large variations observed in control group, tumors can obscure detection of significant therapeutic effects due to the ambiguity in attributing causes of change. This can hinder development of effective therapies due to limitations in experimental design rather than due to therapeutic failure. An improved method to model biological variation and heterogeneity in imaging signals is described. Specifically, linear Poisson modeling (LPM) evaluates changes in apparent diffusion co-efficient between baseline and 72 h after radiotherapy, in two xenograft models of colorectal cancer. The statistical significance of measured changes is compared to those attainable using a conventional t-test analysis on basic apparent diffusion co-efficient distribution parameters. Results: When LPMs were applied to treated tumors, the LPMs detected highly significant changes. The analyses were significant for all tumors, equating to a gain in power of 4-fold (i.e. equivalent to having a sample size 16 times larger), compared with the conventional approach. In contrast, highly significant changes are only detected at a cohort level using t-tests, restricting their potential use within personalized medicine and increasing the number of animals required during testing. Furthermore, LPM enabled the relative volumes of responding and non-responding tissue to be estimated for each xenograft model. Leave-one-out analysis of the treated xenografts provided quality control and identified potential outliers, raising confidence in LPM data at clinically relevant sample sizes. Availability and implementation: TINA Vision open source software is available from www.tina-vision.net. Supplementary information: Supplementary data are available at Bioinformatics online.
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Biología Computacional/métodos , Modelos Estadísticos , Neoplasias/radioterapia , Programas Informáticos , Ensayos Antitumor por Modelo de Xenoinjerto/métodos , Animales , Línea Celular Tumoral , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/radioterapia , Neoplasias Colorrectales/terapia , Femenino , Células HCT116 , Humanos , Modelos Lineales , Imagen por Resonancia Magnética , Ratones , Neoplasias/diagnóstico por imagen , Neoplasias/patología , Neoplasias/terapia , Tamaño de la Muestra , Resultado del TratamientoRESUMEN
OBJECTIVES: Chronic venous disease (CVD) is common, affecting a quarter of the population. Current conservative methods of treatment aim to prevent progression of disease by reducing ambulatory venous pressure. Neuromuscular electrical stimulation (NMES) refers to the use of electrical impulses to elicit muscle contraction. This pilot randomised controlled trial investigates the effect of a footplate NMES device (REVITIVE) on venous flow parameters, limb oedema, and quality of life outcome measures in patients with CVD. METHODS: Twenty-two patients with Clinical Etiological Anatomical and Pathophysiological (CEAP) clinical class C2-C4 venous disease were randomised to receive a sham or test device. The recommended duration of use was for 30 minutes daily for 6 weeks. Venous flow parameters (duplex ultrasound), limb volume (optoelectric volumeter), and quality of life outcome measures were measured at baseline and after 6 weeks. RESULTS: The mean age of participants was 62 years, body mass index 28.6, with a 15:7 female preponderance. There was a significant difference in the percentage change in femoral vein flow parameters (from baseline) between the test and sham group while using the device (Week 0 time-averaged mean velocity 102.4% vs. -9.1%, p < .0001; volume flow 107.9% vs. -3.7%, p < .0001; peak velocity 377.7% vs. -6.7%, p < .0001). Limb volume was observed to increase significantly in the sham group (2.0% at Week 0 and 1.2% at Week 6; p < .01). This was prevented in the test group (+0.8% at Week 0 and 1.0% at Week 6; p = .06). There was a significant difference in the Aberdeen Varicose Vein Questionnaire between the two groups over the 6 weeks. CONCLUSIONS: This trial demonstrated a significant difference in venous flow parameters and prevention of orthostatic limb oedema with NMES. There was a positive effect on quality of life. Larger studies are required to determine the clinical significance of this in patients with venous disease.
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Terapia por Estimulación Eléctrica/métodos , Enfermedades Vasculares/terapia , Anciano , Enfermedad Crónica , Edema/prevención & control , Terapia por Estimulación Eléctrica/instrumentación , Femenino , Vena Femoral/fisiología , Humanos , Extremidad Inferior/irrigación sanguínea , Masculino , Persona de Mediana Edad , Contracción Muscular/fisiología , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/fisiología , Cooperación del Paciente , Proyectos Piloto , Calidad de Vida , Flujo Sanguíneo RegionalRESUMEN
BACKGROUND: Pulmonary capillary hemangiomatosis is a rare, vascular obstructive disorder that uniformly causes pulmonary arterial hypertension. Clinically, pulmonary capillary hemangiomatosis is indistinguishable from primary pulmonary arterial hypertension and histology is required for definitive diagnosis. The distinctive histologic feature of pulmonary capillary hemangiomatosis is non-malignant extensive proliferation of capillaries in the alveolar septae. Vasodilator treatment of humans with primary arterial hypertension due to pulmonary capillary hemangiomatosis can result in fatal acute pulmonary edema. Computed tomography is thus critical to discern pulmonary capillary hemangiomatosis from other causes of pulmonary arterial hypertension prior to vasodilator therapy. This is the first report of a vasoproliferative process resembling pulmonary capillary hemangiomatosis in the feline species. CASE PRESENTATION: A 15-year-old, male castrated, domestic shorthair cat presented for persistent labored breathing presumptively due to congestive heart failure despite treatment with diuretics for 7 days. Echocardiography showed evidence of hypertrophic cardiomyopathy with severe pulmonary hypertension; however, a normal sized left atrium was not consistent with congestive heart failure. Thoracic computed tomography was performed and showed evidence of diffuse ill-defined nodular ground glass opacities, enlarged pulmonary arteries, and filling defects consistent with pulmonary thromboembolism. The cat acutely decompensated after a single dose of sildenafil and was euthanized. Histopathology of the lungs showed severe multifocal alveolar capillary proliferation with respiratory bronchiolar infiltration, marked type II pneumocyte hyperplasia and multifocal pulmonary arterial thrombosis. CONCLUSION: This is the first description in a cat of a vasoproliferative disorder resembling pulmonary capillary hemangiomatosis complicated by multifocal pulmonary arterial thrombosis. Inspiratory and expiratory ventilator-driven breath holds with angiography revealed lesions predominantly characterized by ground glass opacification and vascular filling defects with absence of air trapping. The results from this report suggest that, as in humans, the cat can develop a pulmonary capillary hemangiomatosis-like disease in which vasodilator therapy to address pulmonary hypertension may lead to fatal pulmonary edema.
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Enfermedades de los Gatos/diagnóstico , Hemangioma Capilar/veterinaria , Hipertensión Pulmonar/veterinaria , Animales , Capilares/patología , Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/veterinaria , Gatos , Diagnóstico Diferencial , Resultado Fatal , Hemangioma Capilar/diagnóstico , Hipertensión Pulmonar/diagnóstico , Pulmón/irrigación sanguínea , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/veterinaria , MasculinoRESUMEN
BACKGROUND: Peripheral arterial disease (PAD) is common and symptoms can be debilitating and lethal. Risk management, exercise, radiological and surgical intervention are all valuable therapies, but morbidity and mortality rates from this disease are increasing. Circulatory enhancement can be achieved using simple medical electronic devices, with claims of minimal adverse side effects. The evidence for these is variable, prompting a review of the available literature. METHODS: Embase and Medline were interrogated for full text articles in humans and written in English. Any external medical devices used in the management of peripheral arterial disease were included if they had objective outcome data. RESULTS: Thirty-one papers met inclusion criteria, but protocols were heterogenous. The medical devices reported were intermittent pneumatic compression (IPC), electronic nerve (NMES) or muscle stimulators (EMS), and galvanic electrical dressings. In patients with intermittent claudication, IPC devices increase popliteal artery velocity (49-70 %) and flow (49-84 %). Gastrocnemius EMS increased superficial femoral artery flow by 140 %. Over 4.5-6 months IPC increased intermittent claudication distance (ICD) (97-150 %) and absolute walking distance (AWD) (84-112 %), with an associated increase in quality of life. NMES of the calf increased ICD and AWD by 82 % and 61-150 % at 4 weeks, and 26 % and 34 % at 8 weeks. In patients with critical limb ischaemia IPC reduced rest pain in 40-100 % and was associated with ulcer healing rates of 26 %. IPC had an early limb salvage rate of 58-83 % at 1-3 months, and 58-94 % at 1.5-3.5 years. No studies have reported the use of EMS or NMES in the management of CLI. CONCLUSION: There is evidence to support the use of IPC in the management of claudication and CLI. There is a building body of literature to support the use of electrical stimulators in PAD, but this is low level to date. Devices may be of special benefit to those with limited exercise capacity, and in non-reconstructable critical limb ischaemia. Galvanic stimulation is not recommended.
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Terapia por Estimulación Eléctrica/métodos , Claudicación Intermitente/terapia , Aparatos de Compresión Neumática Intermitente , Enfermedad Arterial Periférica/terapia , Trombosis de la Vena/terapia , Manejo de la Enfermedad , Arteria Femoral/patología , Humanos , Claudicación Intermitente/patología , Enfermedad Arterial Periférica/patología , Calidad de Vida , Transductores de Presión , Trombosis de la Vena/patologíaRESUMEN
INTRODUCTION: The prevention and management of venous disease is a therapeutic challenge. Movement of blood through the venous system is augmented by the action of muscles on the deep veins, and can be achieved through the application of electrical current. The efficacy of currently available clinical devices for this purpose is unknown, and is investigated here. METHODS: A literature search of the EMBASE and Medline databases was performed, and studies were included if they were full text articles, written in english, pertaining to venous disease and neuromuscular electrical stimulation (NMES). RESULTS: NMES devices increase venous haemodynamic parameters such as peak velocity and volume flow. Studies report them to be non-inferior to intermittent pneumatic compression. They are effective in the prevention of venous thromboembolism, though inferior to low molecular weight heparin. NMES can reduce symptoms of chronic venous disease. DISCUSSION: NMES is an important tool in the prevention and management of venous disease, and avoids the significant risks associated with heparin administration. Data explored here is heterogenous in device, protocol, and reported end-points, therefore should be interpreted with care. Long term effects of treatment with NMES have not been explored.
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Estimulación Eléctrica , Tromboembolia Venosa/terapia , Trombosis de la Vena/terapia , Hemodinámica , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Músculo Liso Vascular/fisiología , Unión Neuromuscular/fisiología , Medias de Compresión , Resultado del Tratamiento , Venas/patología , Tromboembolia Venosa/patología , Tromboembolia Venosa/prevención & control , Trombosis de la Vena/patología , Trombosis de la Vena/prevención & controlRESUMEN
Positron emission tomography (PET) and fluorescence labelling have been used to assess the pharmacokinetics, biodistribution and eventual fate of a hydrogel-forming nonapeptide, FEFKFEFKK (F9), in healthy mice, using 18 F-labelled and fluorescein isothiocyanate (FITC)-labelled F9 analogues. F9 was site-specifically radiolabelled with 2-[18 F]fluoro-3-pyridinecarboxaldehyde ([18 F]FPCA) via oxime bond formation. [18 F]FPCA-F9 in vivo fate was evaluated both as a solution, following intravenous administration, and as a hydrogel when subcutaneously injected. The behaviour of FITC-F9 hydrogel was assessed following subcutaneous injection. [18 F]FPCA-F9 demonstrated high plasma stability and primarily renal excretion; [18 F]FPCA-F9 when in solution and injected into the bloodstream displayed prompt bladder uptake (53.4 ± 16.6 SUV at 20 minutes postinjection) and rapid renal excretion, whereas [18 F]FPCA-F9 hydrogel, formed by co-assembly of [18 F]FPCA-F9 monomer with unfunctionalised F9 peptide and injected subcutaneously, showed gradual bladder accumulation of hydrogel fragments (3.8 ± 0.4 SUV at 20 minutes postinjection), resulting in slower renal excretion. Gradual disaggregation of the F9 hydrogel from the site of injection was monitored using FITC-F9 hydrogel in healthy mice (60 ± 3 over 96 hours), indicating a biological half-life between 1 and 4 days. The in vivo characterisation of F9, both as a gel and a solution, highlights its potential as a biomaterial.
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Radioisótopos de Flúor/uso terapéutico , Hidrogeles/química , Oligopéptidos/química , Oligopéptidos/uso terapéutico , Tomografía de Emisión de Positrones , Secuencia de Aminoácidos , Animales , Estabilidad de Medicamentos , Semivida , Ratones , Oligopéptidos/metabolismo , Oligopéptidos/farmacocinética , Conformación Proteica en Lámina beta , Distribución TisularRESUMEN
Hypoxia, a hallmark of most solid tumours, is a negative prognostic factor due to its association with an aggressive tumour phenotype and therapeutic resistance. Given its prominent role in oncology, accurate detection of hypoxia is important, as it impacts on prognosis and could influence treatment planning. A variety of approaches have been explored over the years for detecting and monitoring changes in hypoxia in tumours, including biological markers and noninvasive imaging techniques. Positron emission tomography (PET) is the preferred method for imaging tumour hypoxia due to its high specificity and sensitivity to probe physiological processes in vivo, as well as the ability to provide information about intracellular oxygenation levels. This review provides an overview of imaging hypoxia with PET, with an emphasis on the advantages and limitations of the currently available hypoxia radiotracers.
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Neoplasias/diagnóstico por imagen , Neoplasias/metabolismo , Hipoxia de la Célula , Humanos , Nitroimidazoles , Tomografía de Emisión de Positrones , Radiofármacos , Planificación de la Radioterapia Asistida por ComputadorRESUMEN
Escherichia coli O157 is a human pathogen carried asymptomatically by cattle and shed in their faeces. Infection can occur from the consumption of contaminated beef or by direct contact. Large variations of E. coli O157 shedding in cattle exist and vary in the number of cattle positive for E. coli O157 and the amount of bacteria (c.f.u./g faeces) shed by positive animals. To investigate E. coli O157 shedding and super-shedding (>104 c.f.u./g) we used daily sampling over two 8-day periods; in January 2013 (n = 12) and February 2013 (n = 21). Samples were tested by direct faecal culture for enumeration and by immunomagnetic separation to detect lower levels of shedding. We identified three patterns of shedding, similar to previously observed descriptions: intermittent, transient and consistent. The most commonly observed pattern was intermittent shedding and variation in the level of shedding could be large. This extreme variation is demonstrated by a heifer from which E. coli O157 could be not detected one day, was super-shedding E. coli O157 the next and was detected as shedding >100 c.f.u./g the following day. Recto-anal mucosal swab testing did not predict super-shedding in this cohort of heifers. The variable individual patterns of shedding suggest that a common mechanism of infection may not operate within such a herd when considering previously described patterns and the inferred mechanisms. The sporadic and intermittent nature of shedding is a challenge to identifying risk factors and potential intervention strategies.
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Derrame de Bacterias , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/epidemiología , Animales , Bovinos , Estudios de Cohortes , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/aislamiento & purificación , Heces/microbiología , Femenino , Nueva Gales del Sur/epidemiología , Factores de TiempoRESUMEN
We undertook a longitudinal study within a cohort of 52 dairy heifers maintained under constant management systems and sampled weekly to investigate a comprehensive range of risk factors which may influence shedding or super-shedding of E. coli O157 (detected by direct faecal culture and immunomagnetic separation). E. coli O157 was detected from 416/933 (44.6%) samples (faeces and recto-anal mucosal swabs) and 32 (3.4%) samples enumerated at >10000 c.f.u./g. Weekly point prevalence ranged from 9.4% to 94.3%. Higher temperature (P < 0.001), rainfall (P = 0.02), relative humidity (P < 0.001), pasture growth (P = 0.013) and body score (P = 0.029) were positively associated with increased shedding. Higher rainfall (P < 0.001), hide contamination (P = 0.002) and increased faecal consistency (P = 0.023) were positively associated with super-shedding. Increased solar exposure had a negative effect on both shedding and super-shedding within bivariate analyses but in the final multivariate model for shedding demonstrated a positive effect (P = 0.017). Results suggest that environmental factors are important in E. coli O157 shedding in cattle.
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Derrame de Bacterias , Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157 , Humedad , Lluvia , Temperatura , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Infecciones por Escherichia coli/epidemiología , Heces/microbiología , Femenino , Estudios Longitudinales , Análisis Multivariante , Prevalencia , Factores de RiesgoRESUMEN
Progressive lung fibrosis in humans, typified by idiopathic pulmonary fibrosis (IPF), is a serious cause of morbidity and mortality in people. Similar diseases have been described in dogs, cats, and horses. The cause and pathogenesis of such diseases in all species is poorly understood. There is growing evidence in human medicine that IPF is a manifestation of abnormal wound repair in response to epithelial injury. Because viruses can contribute to epithelial injury, there is increasing interest in a possible role of viruses, particularly gammaherpesviruses, in the pathogenesis of pulmonary fibrosis. This review provides background information on progressive fibrosing lung disease in human and veterinary medicine and summarizes the evidence for an association between gammaherpesvirus infection and pulmonary fibrosis, especially Epstein-Barr virus in human pulmonary fibrosis, and equine herpesvirus 5 in equine multinodular pulmonary fibrosis. Data derived from experimental lung infection in mice with the gammaherpesvirus murine herpesvirus are presented, emphasizing the host and viral factors that may contribute to lung fibrosis. The experimental data are considered in the context of the pathogenesis of naturally occurring pulmonary fibrosis in humans and horses.
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Gammaherpesvirinae/fisiología , Infecciones por Herpesviridae/virología , Enfermedades de los Caballos/virología , Fibrosis Pulmonar/virología , Animales , Animales Domésticos , Modelos Animales de Enfermedad , Infecciones por Herpesviridae/patología , Enfermedades de los Caballos/patología , Caballos , Humanos , Pulmón/patología , Pulmón/virología , Ratones , Fibrosis Pulmonar/patologíaRESUMEN
BACKGROUND: Small-cell lung cancer (SCLC) has a very aggressive clinical course with early metastasis. This study investigated how the distinctive neuroendocrine characteristics contribute to disease progression and invasion in human SCLC. METHODS: The neuroendocrine phenotype (pro-opiomelanocortin (POMC)) was quantified by ELISA in blood samples from 43 SCLC patients. The neuroendocrine (POMC, chromogranin A, neuron-specific enolase, NCAM) and epithelial (cytokeratin and E-cadherin) phenotypes were investigated, using ELISA and immunocytochemistry/immunohistochemistry. RESULTS: In SCLC patients, 16% had elevated circulating POMC, which was associated with significantly worse survival (P=0.02) and liver metastases (P=0.004). In addition, POMC correlated with epithelial-positive circulating tumour cells (P=0.0002). In a panel of SCLC cell lines, all POMC-secreting cell lines expressed cytokeratin (40% of total). Even after cloning, DMS 79 cells expressed both neuroendocrine and epithelial markers. DMS 79 xenografts secreted POMC into the blood, which mirrored the tumour volume. These xenografts expressed both neuroendocrine and epithelial phenotypes in all tumours, with both phenotypes prevalent in cells invading the surrounding tissue. CONCLUSION: Both neuroendocrine and epithelial phenotypes coexist in human SCLC tumours in vitro and in vivo and this persists in invading tumour cells. In patients, POMC secretion predicts poor survival and liver metastases, suggesting a crucial role of the neuroendocrine phenotype.
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Carcinoma de Células Pequeñas/sangre , Carcinoma de Células Pequeñas/patología , Células Epiteliales/patología , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/patología , Células Neuroendocrinas/patología , Proopiomelanocortina/sangre , Animales , Cadherinas/biosíntesis , Ensayo de Inmunoadsorción Enzimática , Células Epiteliales/metabolismo , Humanos , Queratinas/biosíntesis , Neoplasias Hepáticas/sangre , Neoplasias Hepáticas/secundario , Ratones , Ratones Desnudos , Metástasis de la Neoplasia , Células Neoplásicas Circulantes/patología , Células Neuroendocrinas/metabolismo , Fenotipo , Tasa de Supervivencia , Trasplante HeterólogoRESUMEN
REASONS FOR PERFORMING THE STUDY: Exercise-induced pulmonary haemorrhage (EIPH) occurs in nearly all strenuously exercising horses. Recent studies have attempted to identify the role of free blood within the airspaces, in the lung fibrosis that develops within the lungs of EIPH horses. HYPOTHESIS: Repeated exposure of the equine lung to autologous blood results in lung fibrosis similar to that observed in spontaneous EIPH. METHODS: Forty ml of autologous blood from the jugular vein was instilled into preselected lung regions of 6 horses one, 2, 3, 4 or 5 times at 2 week intervals, with 40 ml of saline instilled into the contralateral lung serving as a control. The time interval between instillation of the first blood and euthanasia ranged from 2-10 weeks. The lung from each instillation site was harvested, and the histopathology was scored from each region based upon the presence and abundance of blood, haemosiderin and interstitial collagen. Consequently, at the time of euthanasia, the time since instillation of the first blood ranged from 2-10 weeks. RESULTS: Beyond retention of blood, and the accumulation of haemosiderin, there was no visible increase in perivascular and interstitial collagen within the blood-instilled lung sites. In a small number of regions, there were foci of bronchiolitis obliterans organising pneumonia with collagen accumulation within these foci, but no collagen accumulation with the characteristic perivascular and interstitial histological distribution seen in EIPH. CONCLUSIONS: Free blood within the airways of horses does not result in a qualitative increase in the amount of interstitial collagen within 8-10 weeks, and is therefore an unlikely aetiological factor in the lung collagen accumulation that occurs in EIPH. POTENTIAL RELEVANCE: This study emphasises the efficiency of the equine lung in clearing blood from the airspaces. Further, it suggests that the aetiopathogenesis of EIPH is not driven by events within the airspace lumen, but rather emanates from within the vasculature and lung interstitium.
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Enfermedades de los Caballos/patología , Fibrosis Pulmonar/veterinaria , Animales , Bronquiolitis Obliterante/patología , Bronquiolitis Obliterante/veterinaria , Caballos , Fibrosis Pulmonar/patologíaRESUMEN
BACKGROUND: Metastases cause most cancer-related deaths. We investigated the use of hypoxia-selective cytotoxins as adjuvants to radiotherapy in the control of metastatic tumour growth. METHODS: The NLCQ-1, RB6145 and tirapazamine were assessed against the spontaneously metastasising KHT model. Subcutaneous KHT tumours (250 mm(3)) were irradiated with 25 Gy (single fraction) to control primary growth. Equitoxic drug treatments (NLCQ-1 (10 mg kg(-1)) once daily; RB6145 (75 mg kg(-1)) and tirapazamine (13 mg kg(-1)) twice daily) were administered 3-6 days post-radiotherapy when hypoxic cells were evident in lung micrometastases. Mice were culled when 50% of controls exhibited detrimental signs of lung metastases. RESULTS: In total, 95% of control mice presented with lung disease. This was significantly reduced by NLCQ-1 (33%; P=0.0002) and RB6145 (60%; P=0.02). Semi-quantitative grading of lung disease revealed a significant improvement with all treatments, with NLCQ-1 proving most efficacious (median grades: control, 4; NLCQ, 0 (P<0.0001); RB6145, 1 (P<0.001), tirapazamine, 3 (P=0.007)). Positron emission tomography (PET) was evaluated as a non-invasive means of assessing metastatic development. Primary and metastatic KHT tumours showed robust uptake of [(18)F]fluorodeoxyglucose ([(18)F]FDG). Metastatic burden discernable by [(18)F]FDG PET correlated well with macroscopic and histological lung analysis. CONCLUSION: The hypoxia-selective cytotoxin NLCQ-1 controls metastatic disease and may be a successful adjuvant to radiotherapy in the clinical setting.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Hipoxia de la Célula/efectos de los fármacos , Imidazoles/administración & dosificación , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/secundario , Quinolinas/administración & dosificación , Sarcoma/tratamiento farmacológico , Sarcoma/secundario , Animales , Línea Celular Tumoral , Quimioterapia Adyuvante , Terapia Combinada , Esquema de Medicación , Evaluación Preclínica de Medicamentos , Ratones , Ratones Endogámicos C3H , Metástasis de la Neoplasia , Nitroimidazoles/administración & dosificación , Tirapazamina , Triazinas/administración & dosificaciónRESUMEN
BACKGROUND: Hypoxia is as an indicator of poor treatment outcome. Consistently, hypoxic HCT116 colorectal cancer cells are resistant to oxaliplatin, although the mechanistic basis is unclear. This study sought to investigate the relative contribution of HIF-1 (hypoxia-inducible factor-1)-mediated gene expression and drug penetrance to oxaliplatin resistance using three-dimensional spheroids. METHODS: Hypoxia-inducible factor-1alpha function was suppressed by the stable expression of a dominant-negative form in HCT116 cells (DN). Cells were drug exposed as monolayer or multicellular spheroid cultures. Cells residing at differing oxygenation status were isolated from Hoechst 33342-treated spheroids using flow cytometry. Sub-populations were subjected to clonogenic survival assays and to Inductively-Coupled Plasma Mass Spectroscopy to determine oxaliplatin uptake. RESULTS: In spheroids, a sensitivity gradient (hypoxicAsunto(s)
Antineoplásicos/farmacología
, Neoplasias Colorrectales/tratamiento farmacológico
, Factor 1 Inducible por Hipoxia/fisiología
, Compuestos Organoplatinos/farmacología
, Hipoxia de la Célula
, Supervivencia Celular/efectos de los fármacos
, Neoplasias Colorrectales/metabolismo
, Neoplasias Colorrectales/patología
, Resistencia a Antineoplásicos
, Células HCT116
, Humanos
, Compuestos Organoplatinos/farmacocinética
, Oxaliplatino
, Esferoides Celulares
RESUMEN
The female hybrid hare (Lepus timidus x Lepus europaeus) is heterozygous for electrophoretically separable, X-linked isoenzymes of glucose-6-phosphate dehydrogenase. The isoenzymes of this animal have been used as cellular markers in the study of the clonal origins of experimentally induced atherosclerotic lesions. Aortic lesions produced in the hybrid hare by feeding cholesterol and injuring the aortic wall with a catheter have been shown to have polyclonal characteristics and in this way are fundamentally different from atherosclerotic fibrous plaques in man.
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Arteriosclerosis/patología , Células Clonales/patología , Modelos Animales de Enfermedad , Animales , Arteriosclerosis/enzimología , Cateterismo/métodos , Células Clonales/enzimología , Dieta Aterogénica , Glucosafosfato Deshidrogenasa/metabolismo , Isoenzimas/metabolismo , ConejosRESUMEN
REASONS FOR PERFORMING STUDY: Regional veno-occlusive remodelling of pulmonary veins in EIPH-affected horses, suggests that pulmonary veins may be central to pathogenesis. The current study quantified site-specific changes in vein walls, collagen and haemosiderin accumulation, and pleural vascular profiles in the lungs of horses suffering EIPH. HYPOTHESIS: In the caudodorsal lung regions of EIPH-affected horses, there is veno-occlusive remodelling with haemosiderosis, angiogenesis and fibrosis of the interstitium, interlobular septa and pleura. METHODS: Morphometric methods were used to analyse the distribution and accumulation of pulmonary collagen and haemosiderin, and to count pleural vascular profiles in the lungs of 5 EIPH-affected and 2 control horses. RESULTS: Vein wall thickness was greatest in the dorsocaudal lung and significantly correlated with haemosiderin accumulation. Increased venous, interstitial, pleural and septal collagen; lung haemosiderin; and pleural vascular profiles occurred together and changes were most pronounced in the dorsocaudal lung. Further, haemosiderin accumulation colocalised with decreased pulmonary vein lumen size. Vein wall thickening, haemosiderin accumulation and histological score were highly correlated and these changes occurred only in the caudodorsal part of the lung. CONCLUSION: The colocalisation of these changes suggests that regional (caudodorsal) venous remodelling plays an important role in the pathogenesis of EIPH. POTENTIAL RELEVANCE: The results support the hypothesis that repeated bouts of venous hypertension during strenuous exercise cause regional vein wall remodelling and collagen accumulation, venous occlusion and pulmonary capillary hypertension. Subjected to these high pressures, there is capillary stress failure, bleeding, haemosiderin accumulation and, subsequently, lung fibrosis.
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Colágeno/metabolismo , Hemorragia/veterinaria , Hemosiderina/metabolismo , Enfermedades de los Caballos/patología , Enfermedades Pulmonares/veterinaria , Condicionamiento Físico Animal/efectos adversos , Animales , Hemorragia/etiología , Hemorragia/patología , Enfermedades de los Caballos/etiología , Caballos , Pulmón/irrigación sanguínea , Pulmón/metabolismo , Enfermedades Pulmonares/etiología , Enfermedades Pulmonares/patología , Venas Pulmonares/patologíaRESUMEN
Active flow control using automated gates and weirs aims to utilise available dispersed storage within sewer systems to alleviate the severity and frequency of localised flooding incidents. Whilst a previous study has demonstrated its potential, a key operational concern before implementation was sedimentation. An experimental programme was designed to investigate the sediment deposition created when using a flow control device. Tests were also undertaken to examine the potential for rapid gate opening to flush away any resulting deposits. In catchments dominated by fine material in suspension, the use of an active flow control device can result in a uniformly thick deposit upstream of the gate. Rapid gate opening results in deposited material eroding in large sections starting at the gate and moving in an upstream direction. Granular sediment forms a series of discrete bedforms which are fairly uniform regardless of the flow conditions and a larger deposit further upstream. The potential for flushing granular deposits is limited and modification of the operation of the gate has shown little potential for increasing the effectiveness. Therefore, active flow control using a single downstream gate may only be suitable in systems with fine material moving in suspension during dry weather flow and not where there is significant granular sediment.
Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos/métodos , Movimientos del AguaRESUMEN
BACKGROUND: The DREAMtherapy (Dual REctal Angiogenesis MEK inhibition radiotherapy) trial is a novel intertwined design whereby two tyrosine kinase inhibitors (cediranib and selumetinib) were independently evaluated with rectal chemoradiotherapy (CRT) in an efficient manner to limit the extended follow-up period often required for radiotherapy studies. PATIENTS AND METHODS: Cediranib or selumetinib was commenced 10 days before and then continued with RT (45 Gy/25#/5 wks) and capecitabine (825 mg/m2 twice a day (BID)). When three patients in the cediranib 15-mg once daily (OD) cohort were in the surveillance period, recruitment to the selumetinib cohort commenced. This alternating schedule was followed throughout. Three cediranib (15, 20 and 30 mg OD) and two selumetinib cohorts (50 and 75 mg BID) were planned. Circulating and imaging biomarkers of inflammation/angiogenesis were evaluated. RESULTS: In case of cediranib, dose-limiting diarrhoea, fatigue and skin reactions were seen in the 30-mg OD cohort, and therefore, 20 mg OD was defined as the maximum tolerated dose. Forty-one percent patients achieved a clinical or pathological complete response (7/17), and 53% (9/17) had an excellent clinical or pathological response (ECPR). Significantly lower level of pre-treatment plasma tumour necrosis factor alpha (TNFα) was found in patients who had an ECPR. In case of selumetinib, the 50-mg BID cohort was poorly tolerated (fatigue and diarrhoea); a reduced dose cohort of 75-mg OD was opened which was also poorly tolerated, and further recruitment was abandoned. Of the 12 patients treated, two attained an ECPR (17%). CONCLUSIONS: This novel intertwined trial design is an effective way to independently investigate multiple agents with radiotherapy. The combination of cediranib with CRT was well tolerated with encouraging efficacy. TNFα emerged as a potential predictive biomarker of response and warrants further evaluation.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quimioradioterapia/métodos , Neoplasias del Recto/terapia , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Bencimidazoles/administración & dosificación , Biomarcadores de Tumor , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Pronóstico , Quinazolinas/administración & dosificación , Neoplasias del Recto/patología , Distribución TisularRESUMEN
INTRODUCTION: Rates of overweight among US children have been rising over the past three decades. Changes in lifestyle behaviors, including dietary and physical activity habits, have been examined thoroughly to identify correlates of weight status in children. Youth in rural US Appalachia are at a disproportionately greater risk for obesity and related health complications. Inadequate physical activity and poor dietary habits are two primary causes of obesity that have been noted in West Virginia adolescents. Few existing data describes the decisional balance in performing lifestyle behaviors, nor the perceptions of these youth regarding their beliefs about weight. The purpose of this study was to identify the perceptions of a healthy weight in rural Appalachian adolescents. METHODS: Ninth grade students were recruited from classroom presentations in four high schools throughout West Virginia. Interested parent-caregiver pairs returned forms to indicate interest in participation. Separate focus group interviews were conducted concurrently with adolescent and parents or caregivers to identify the cultural perceptions of a healthy weight. Questions were developed using grounded theory to explore how a healthy weight was defined, what factors dictate body weight, the perceived severity of the obesity issue, and the social or health ramifications of the condition. Verbatim transcripts were analyzed to identify dominant themes, and content analysis provided text segments to describe the themes. This article describes the data obtained from the adolescent focus groups. RESULTS: When asked what defined a healthy weight, the adolescents who participated in the focus groups placed great value on physical appearance and social acceptability. Students believed there was a particular number, either an absolute weight or body mass index value that determined a healthy weight. These numbers were usually conveyed by a physician; however, there was also a general acceptance of being 'thick' or a reliance on 'feeling healthy' as a determinant of maintaining a healthy weight. Despite these beliefs, many teens had unrealistic and unhealthy perceptions of weight. Female participants were more concerned with weight than males, some to the point of obsession. Both males and females expressed a social stigma associated with overweight. Issues of guilt and diminished self-esteem were prevalent. When asked about the extensiveness of the problem of childhood overweight, the students indicated that a degree of familiarity with being overweight has developed and 'you just get used to [seeing] it.' Because of the rising rates of chronic disease in this region, a fear was evident in these youth about the increased risk of developing these conditions in those who are overweight. Experiences with family members with diabetes and cardiovascular disease fueled these concerns, which instilled a fear of becoming overweight in many of the students. Many perceptions of healthy weight and appropriate body size were shaped by the media and entertainment industry. Additionally, some participants admitted to performing unsafe practices to reduce body mass, such as very low calorie diets or fasting. CONCLUSIONS: Youth in rural Appalachia present similar perceptions about weight as other children; however, differences in perceived healthy lifestyle habits and a general acceptance of a higher average body weight present additional challenges to addressing the increasing problem of child overweight. Despite the relative isolation of many of these communities, the media has a profound impact on weight valuation that has been intertwined with school-based health education and cultural values of health. These data will provide valuable information for the development of obesity prevention programs in rural Appalachia.