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OBJECTIVE: To evaluate the cost-effectiveness of point-of-care duplex ultrasound (PAD-scan) and other bedside tests for the diagnosis of peripheral arterial disease (PAD) in people with diabetes. BACKGROUND: PAD is a risk factor for cardiovascular disease, diabetic foot ulceration (DFU), and amputation in diabetic patients. Diagnosis enables optimization of therapies to manage these risks. PAD-scan can be performed by frontline staff and has been shown to be the most accurate bedside test. However, its cost-effectiveness has not been investigated. METHODS: A Markov model was constructed to estimate the health outcomes and costs over 5 years of different testing strategies applied to a cohort of diabetic patients. Bedside tests investigated were PAD-scan, ankle-brachial pressure index, toe-brachial pressure index, audible and visual Doppler, transcutaneous pressure of oxygen, and pulse palpation. Health outcomes were incidence of new DFU, major cardiovascular events, amputation, death, and DFU healing rates. Sensitivity analyses were performed. RESULTS: PAD-scan was the most cost-effective bedside test with an incremental cost-effectiveness ratio of £11,391/quality-adjusted life years. PADscan had the highest probability (78.7%) of having the greatest net benefit at a willingness to pay threshold of £20,000 per quality-adjusted life years. It reduced the number of amputations by 24% and the number of cardiovascular deaths by 10% over 5 years, compared to toe-brachial pressure index (next best alternative). PAD-scans superiority in incremental cost-effectiveness ratio occurred at a PAD prevalence threshold of 0.24. DISCUSSION: PAD-scan is a cost-effective test for the detection of PAD in patients with diabetes.
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Diabetes Mellitus , Pé Diabético , Doença Arterial Periférica , Humanos , Análise Custo-Benefício , Doença Arterial Periférica/terapia , Pé Diabético/diagnóstico , Pé Diabético/terapia , Fatores de Risco , Amputação CirúrgicaRESUMO
Master splicing regulator MBNL1 shapes large transcriptomic changes that drive cellular differentiation during development. Here we demonstrate that MBNL1 is a suppressor of tumor dedifferentiation. We surveyed MBNL1 expression in matched tumor/normal pairs across The Cancer Genome Atlas and found that MBNL1 was down-regulated in several common cancers. Down-regulation of MBNL1 predicted poor overall survival in breast, lung, and stomach adenocarcinomas and increased relapse and distant metastasis in triple-negative breast cancer. Down-regulation of MBNL1 led to increased tumorigenic and stem/progenitor-like properties in vitro and in vivo. A discrete set of alternative splicing events (ASEs) are shared between MBNL1-low cancers and embryonic stem cells including a MAP2K7∆exon2 splice variant that leads to increased stem/progenitor-like properties via JNK activation. Accordingly, JNK inhibition is capable of reversing MAP2K7∆exon2-driven tumor dedifferentiation in MBNL1-low cancer cells. Our work elucidates an alternative-splicing mechanism that drives tumor dedifferentiation and identifies biomarkers that predict enhanced susceptibility to JNK inhibition.
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MAP Quinase Quinase 4/metabolismo , MAP Quinase Quinase 7/genética , MAP Quinase Quinase 7/metabolismo , Neoplasias/metabolismo , Proteínas de Ligação a RNA/metabolismo , Diferenciação Celular , Humanos , MAP Quinase Quinase 4/genética , Neoplasias/genética , Neoplasias/fisiopatologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Splicing de RNA , Proteínas de Ligação a RNA/genéticaRESUMO
BACKGROUND: Venous disease is the most common cause of leg ulceration. Although compression therapy improves venous ulcer healing, it does not treat the underlying causes of venous hypertension. Treatment of superficial venous reflux has been shown to reduce the rate of ulcer recurrence, but the effect of early endovenous ablation of superficial venous reflux on ulcer healing remains unclear. METHODS: In a trial conducted at 20 centers in the United Kingdom, we randomly assigned 450 patients with venous leg ulcers to receive compression therapy and undergo early endovenous ablation of superficial venous reflux within 2 weeks after randomization (early-intervention group) or to receive compression therapy alone, with consideration of endovenous ablation deferred until after the ulcer was healed or until 6 months after randomization if the ulcer was unhealed (deferred-intervention group). The primary outcome was the time to ulcer healing. Secondary outcomes were the rate of ulcer healing at 24 weeks, the rate of ulcer recurrence, the length of time free from ulcers (ulcer-free time) during the first year after randomization, and patient-reported health-related quality of life. RESULTS: Patient and clinical characteristics at baseline were similar in the two treatment groups. The time to ulcer healing was shorter in the early-intervention group than in the deferred-intervention group; more patients had healed ulcers with early intervention (hazard ratio for ulcer healing, 1.38; 95% confidence interval [CI], 1.13 to 1.68; P=0.001). The median time to ulcer healing was 56 days (95% CI, 49 to 66) in the early-intervention group and 82 days (95% CI, 69 to 92) in the deferred-intervention group. The rate of ulcer healing at 24 weeks was 85.6% in the early-intervention group and 76.3% in the deferred-intervention group. The median ulcer-free time during the first year after trial enrollment was 306 days (interquartile range, 240 to 328) in the early-intervention group and 278 days (interquartile range, 175 to 324) in the deferred-intervention group (P=0.002). The most common procedural complications of endovenous ablation were pain and deep-vein thrombosis. CONCLUSIONS: Early endovenous ablation of superficial venous reflux resulted in faster healing of venous leg ulcers and more time free from ulcers than deferred endovenous ablation. (Funded by the National Institute for Health Research Health Technology Assessment Program; EVRA Current Controlled Trials number, ISRCTN02335796 .).
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Técnicas de Ablação , Úlcera Varicosa/terapia , Técnicas de Ablação/efeitos adversos , Técnicas de Ablação/métodos , Idoso , Ablação por Cateter , Feminino , Seguimentos , Humanos , Terapia a Laser , Masculino , Pessoa de Meia-Idade , Escleroterapia , Resultado do Tratamento , Úlcera Varicosa/cirurgia , CicatrizaçãoRESUMO
PURPOSE: To compare clinical outcomes between transtibial drilling and anteromedial portal techniques for anterior cruciate ligament (ACL) reconstruction using soft-tissue grafts secured with expandable fixation. METHODS: Patients undergoing soft-tissue ACL reconstruction using expandable fixation between 2007 and 2011 were reviewed for inclusion in this study. Revision ACL cases were excluded. All surgeries were performed by 1 of 2 sports medicine fellowship-trained surgeons (T.S.D., K.D.M.). A total of 128 patients (67 comprising transtibial cohort and 61 comprising anteromedial portal cohort) had a minimum of 24 months' follow-up (mean, 27 months) and met the inclusion criteria. The patients were divided into 2 groups based on the method used for creation of the femoral tunnel. At final follow-up, outcomes were assessed with KT-1000 (MEDmetric, San Diego, CA) measurements, as well as International Knee Documentation Committee, Lysholm, and Tegner scores. Data were screened for normality and skew before use of parametric statistics and were transformed if necessary. Data were analyzed by 1-way analysis of variance with post hoc paired comparisons using the Bonferroni approximation. RESULTS: No differences in demographic characteristics were observed between the 2 groups. There was no significant difference in postoperative KT-1000 measurements between the 2 cohorts (1.571 ± 0.2275 mm in transtibial cohort [n = 35] and 1.246 ± 0.09249 mm in anteromedial cohort [n = 61], P = .1259). A significant improvement in International Knee Documentation Committee scores was observed in the anteromedial cohort, increasing from 41 ± 16 to 89 ± 7.4 (mean ± SD) (P < .0001). Similar changes were observed for the Lysholm score. There was no significant difference between cohorts for any postoperative scores measured (P > .2). CONCLUSIONS: Our data show comparable KT-1000 measurements for both anteromedial and transtibial femoral drilling techniques when using a soft-tissue graft with expandable fixation. LEVEL OF EVIDENCE: Level IV, therapeutic case series.
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Reconstrução do Ligamento Cruzado Anterior/métodos , Fêmur/cirurgia , Ligamentos/transplante , Osteotomia/métodos , Tíbia/cirurgia , Adolescente , Adulto , Ligamento Cruzado Anterior/cirurgia , Lesões do Ligamento Cruzado Anterior , Estudos de Coortes , Feminino , Humanos , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
Blood vessel leakiness is an early, transient event in acute inflammation but can also persist as vessels undergo remodeling in sustained inflammation. Angiopoietin/Tie2 signaling can reduce the leakiness through changes in endothelial cells. The role of pericytes in this action has been unknown. We used the selective PDGF-B-blocking oligonucleotide aptamer AX102 to determine whether disruption of pericyte-endothelial crosstalk alters vascular leakiness or remodeling in the airways of mice under four different conditions: i) baseline, ii) acute inflammation induced by bradykinin, iii) sustained inflammation after 7-day infection by the respiratory pathogen Mycoplasma pulmonis, or iv) leakage after bradykinin challenge in the presence of vascular stabilization by the angiopoietin-1 (Ang1) mimic COMP-Ang1 for 7 days. AX102 reduced pericyte coverage but did not alter the leakage of microspheres from tracheal blood vessels at baseline or after bradykinin; however, AX102 exaggerated leakage at 7 days after M. pulmonis infection and increased vascular remodeling and disease severity at 14 days. AX102 also abolished the antileakage effect of COMP-Ang1 at 7 days. Together, these findings show that pericyte contributions to endothelial stability have greater dependence on PDGF-B during the development of sustained inflammation, when pericyte dynamics accompany vascular remodeling, than under baseline conditions or in acute inflammation. The findings also show that the antileakage action of Ang1 requires PDGF-dependent actions of pericytes in maintaining endothelial stability.
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Angiopoietina-1/metabolismo , Inflamação/patologia , Pericitos/patologia , Traqueia/irrigação sanguínea , Traqueia/patologia , Actinas/metabolismo , Animais , Aptâmeros de Nucleotídeos/farmacologia , Bradicinina/farmacologia , Contagem de Células , Forma Celular/efeitos dos fármacos , Desmina/metabolismo , Inflamação/complicações , Camundongos , Camundongos Endogâmicos C57BL , Microesferas , Infecções por Mycoplasma/complicações , Infecções por Mycoplasma/patologia , Mycoplasma pulmonis/efeitos dos fármacos , Mycoplasma pulmonis/fisiologia , Pericitos/efeitos dos fármacos , Pericitos/microbiologia , Proteínas Proto-Oncogênicas c-sis/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-sis/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Traqueia/microbiologiaRESUMO
PURPOSE: To prove that the assessment of osteochondral graft perpendicularity with magnetic resonance imaging (MRI) will allow for a precise measurement of graft perpendicularity and for an improved comparison of arthroscopic versus mini-open harvest techniques. METHODS: Ten fresh cadaveric knees (mean age, 39.4 years) underwent harvest of 6-mm osteochondral plugs using the Osteochondral Autograft Transfer System (OATS; Arthrex, Naples, FL). A total of 8 plugs were harvested per knee from 3 donor sites: the lateral supracondylar ridge, the medial supracondylar ridge, and the lateral intercondylar notch. Two surgeons performed the graft harvest, alternating between mini-open (5 specimens) and arthroscopic (5 specimens) techniques to minimize bias. The osteochondral plugs were labeled and plated by a novel agar plating technique and then underwent MRI for measurement of graft perpendicularity. The data were analyzed to look for a significant difference in perpendicularity between the 2 harvest techniques, as well as overall graft acceptability. RESULTS: One specimen in the open harvest technique group was unable to undergo optimal MRI because of difficulties encountered with the novel agar plating system resulting in graft movement during imaging. When we compared the mini-open and arthroscopic harvest techniques, the mean angle of perpendicularity at the lateral intercondylar notch harvest site was 84.1° and 84.2°, respectively (P = .958). At the medial supracondylar ridge harvest site, the mean angle of perpendicularity for the mini-open and arthroscopic techniques was 88.4° and 81.0°, respectively, with a mean difference of 7.4° (P = .006). At the lateral supracondylar ridge harvest site, the mean angle of perpendicularity for the mini-open and arthroscopic techniques was 85.7° and 87.1°, respectively (P = .237). CONCLUSIONS: A significant difference in osteochondral autograft perpendicularity was noted at the medial supracondylar ridge when we compared the mini-open and arthroscopic harvesting techniques. This suggests that when one is harvesting autologous osteochondral grafts from the medial supracondylar ridge, the mini-open technique may be preferred. CLINICAL RELEVANCE: When harvesting autologous osteochondral grafts from the medial supracondylar ridge of the knee, the mini-open technique will potentially allow for a more perpendicular graft for implantation.
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Artroscopia/métodos , Cartilagem Articular/anatomia & histologia , Articulação do Joelho , Coleta de Tecidos e Órgãos/métodos , Adulto , Cadáver , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Transplante AutólogoRESUMO
Epithelial to mesenchymal transition (EMT) plays a dual role in tumor progression. It enhances metastasis of tumor cells by increasing invasive capacity and promoting survival, and it decreases tumor cell sensitivity to epithelial cell-targeting agents such as epithelial growth factor receptor kinase inhibitors. In order to study EMT in tumor cells, we have characterized 3 new models of ligand-driven EMT: the CFPAC1 pancreatic tumor model and the H358 and H1650 lung tumor models. We identified a diverse set of ligands that drives EMT in these models. Hepatocyte growth factor and oncostatin M induced EMT in all models, while transforming growth factor-ß induced EMT in both lung models. We observed morphologic, marker and phenotypic changes in response to chronic ligand treatment. Interestingly, stimulation with 2 ligands resulted in more pronounced EMT compared with single-ligand treatment, demonstrating a spectrum of EMT states induced by parallel signaling, such as the JAK and PI3K pathways. The EMT changes observed in response to the ligand were reversed upon ligand withdrawal, demonstrating the 'metastable' nature of these models. To study the impact of EMT on cell morphology and invasion in a 3D setting, we cultured cells in a semisolid basement membrane extract. Upon stimulation with EMT ligands, the colonies exhibited changes to EMT markers and showed phenotypes ranging from modest differences in colony architecture (CFPAC1) to complex branching structures (H358, H1650). Collectively, these 3 models offer robust cell systems with which to study the roles that EMT plays in cancer progression.
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Transição Epitelial-Mesenquimal/fisiologia , Fator de Crescimento de Hepatócito/metabolismo , Neoplasias Pulmonares/metabolismo , Oncostatina M/metabolismo , Neoplasias Pancreáticas/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Western Blotting , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/genética , Imunofluorescência , Fator de Crescimento de Hepatócito/genética , Humanos , Neoplasias Pulmonares/genética , Microscopia Confocal , Oncostatina M/genética , Neoplasias Pancreáticas/genética , Reação em Cadeia da Polimerase , Fator de Crescimento Transformador beta/genéticaRESUMO
INTRODUCTION: Personalised nutrition (PN) has great potential for disease prevention, particularly if coupled with the power and accessibility of mobile technology. However, success of PN interventions will depend on the willingness of users to subscribe. This study investigates the factors associated with potential users' perceived value of PN and heterogeneity in these values. METHODS: A discrete choice experiment was carried out in a representative sample (N = 429 valid responses) from the adult population in Spain. The results were analysed in line with McFadden's Random Utility Theory, using conditional and mixed logit models in addition to a latent class logit model. RESULTS: The conditional and mixed logit models revealed the existence of a significant preference and willingness to pay for personalised nutrition, but the effect on average was not large for the highest level of personalisation. The latent class logit revealed four classes of respondent: those who would be likely to pay for a high level of personalised nutrition service, those who would use it if it were heavily subsidised, those who would use only a basic nutrition service, and those who would not be willing to engage. These results could be useful for the design and targeting of effective personalised nutrition services. CONCLUSIONS: Over half of adults currently perceive some individual benefit in a high level of PN, which may justify some degree of public subsidy in investment and delivery of such a service.
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Comportamento do Consumidor , Adulto , Humanos , EspanhaRESUMO
The mechanism of acquisition of tumorigenic properties by somatic cells at the onset of cancer and later during relapse is a question of paramount importance in cancer biology. We have recently discovered a Muscleblind like-1 (MBNL1)-driven alternative-splicing mediated mechanism of tumorigenic de-differentiation that is associated with poor prognosis, relapse and metastasis in common cancer types.
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A subset of Wnt-addicted cancers are sensitive to targeted therapies that block Wnt secretion or receptor engagement. RNF43 loss-of-function (LOF) mutations that increase cell surface Wnt receptor abundance cause sensitivity to Wnt inhibitors. However, it is not clear which of the clinically identified RNF43 mutations affect its function in vivo. We assayed 119 missense and 45 truncating RNF43 mutations found in human cancers using a combination of cell-based reporter assays, genome editing, flow cytometry, and immunofluorescence microscopy. Five common germline variants of RNF43 exhibited wild-type activity. Cancer-associated missense mutations in the RING ubiquitin ligase domain and a subset of mutations in the extracellular domain hyperactivate Wnt/ß-catenin signaling through formation of inactive dimers with endogenous RNF43 or ZNRF3. RNF43 C-terminal truncation mutants, including the common G659fs mutant are LOF specifically when endogenous mutations are examined, unlike their behavior in transient transfection assays. Patient-derived xenografts and cell lines with C-terminal truncations showed increased cell surface Frizzled and Wnt/ß-catenin signaling and were responsive to porcupine (PORCN) inhibition in vivo, providing clear evidence of RNF43 impairment. Our study provides potential guidelines for patient assignment, as virtually all RNF43 nonsense and frameshift mutations, including those in the C-terminal domain and a large number of patient-associated missense mutations in the RING domain and N-terminal region compromise its activity, and therefore predict response to upstream Wnt inhibitors in cancers without microsatellite instability. This study expands the landscape of actionable RNF43 mutations, extending the benefit of these therapies to additional patients. SIGNIFICANCE: Systematic examination of patient-derived RNF43 mutations identifies rules to guide patient selection, including that truncation or point mutations in well-defined functional domains sensitize cancers to PORCN inhibitors.
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Mutação , Neoplasias/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , Aciltransferases/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Endocitose/fisiologia , Receptores Frizzled/metabolismo , Regulação Neoplásica da Expressão Gênica , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Proteínas de Membrana/antagonistas & inibidores , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Multimerização Proteica , Via de Sinalização Wnt/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Importance: One-year outcomes from the Early Venous Reflux Ablation (EVRA) randomized trial showed accelerated venous leg ulcer healing and greater ulcer-free time for participants who are treated with early endovenous ablation of lower extremity superficial reflux. Objective: To evaluate the clinical and cost-effectiveness of early endovenous ablation of superficial venous reflux in patients with venous leg ulceration. Design, Setting, and Participants: Between October 24, 2013, and September 27, 2016, the EVRA randomized clinical trial enrolled 450 participants (450 legs) with venous leg ulceration of less than 6 months' duration and superficial venous reflux. Initially, 6555 patients were assessed for eligibility, and 6105 were excluded for reasons including ulcer duration greater than 6 months, healed ulcer by the time of randomization, deep venous occlusive disease, and insufficient superficial venous reflux to warrant ablation therapy, among others. A total of 426 of 450 participants (94.7%) from the vascular surgery departments of 20 hospitals in the United Kingdom were included in the analysis for ulcer recurrence. Surgeons, participants, and follow-up assessors were not blinded to the treatment group. Data were analyzed from August 11 to November 4, 2019. Interventions: Patients were randomly assigned to receive compression therapy with early endovenous ablation within 2 weeks of randomization (early intervention, n = 224) or compression with deferred endovenous treatment of superficial venous reflux (deferred intervention, n = 226). Endovenous modality and strategy were left to the preference of the treating clinical team. Main Outcomes and Measures: The primary outcome for the extended phase was time to first ulcer recurrence. Secondary outcomes included ulcer recurrence rate and cost-effectiveness. Results: The early-intervention group consisted of 224 participants (mean [SD] age, 67.0 [15.5] years; 127 men [56.7%]; 206 White participants [92%]). The deferred-intervention group consisted of 226 participants (mean [SD] age, 68.9 [14.0] years; 120 men [53.1%]; 208 White participants [92%]). Of the 426 participants whose leg ulcer had healed, 121 (28.4%) experienced at least 1 recurrence during follow-up. There was no clear difference in time to first ulcer recurrence between the 2 groups (hazard ratio, 0.82; 95% CI, 0.57-1.17; P = .28). Ulcers recurred at a lower rate of 0.11 per person-year in the early-intervention group compared with 0.16 per person-year in the deferred-intervention group (incidence rate ratio, 0.658; 95% CI, 0.480-0.898; P = .003). Time to ulcer healing was shorter in the early-intervention group for primary ulcers (hazard ratio, 1.36; 95% CI, 1.12-1.64; P = .002). At 3 years, early intervention was 91.6% likely to be cost-effective at a willingness to pay of £20â¯000 ($26â¯283) per quality-adjusted life year and 90.8% likely at a threshold of £35â¯000 ($45â¯995) per quality-adjusted life year. Conclusions and Relevance: Early endovenous ablation of superficial venous reflux was highly likely to be cost-effective over a 3-year horizon compared with deferred intervention. Early intervention accelerated the healing of venous leg ulcers and reduced the overall incidence of ulcer recurrence. Trial Registration: ClinicalTrials.gov identifier: ISRCTN02335796.
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Procedimentos Endovasculares , Custos de Cuidados de Saúde , Úlcera Varicosa/cirurgia , Idoso , Idoso de 80 Anos ou mais , Análise Custo-Benefício , Procedimentos Endovasculares/economia , Feminino , Humanos , Terapia a Laser , Masculino , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , Ablação por Radiofrequência , Recidiva , Fatores de Tempo , Úlcera Varicosa/economia , Úlcera Varicosa/terapia , CicatrizaçãoRESUMO
Comprehensive understanding of aberrant splicing in gastric cancer is lacking. We RNA-sequenced 19 gastric tumor-normal pairs and identified 118 high-confidence tumor-associated (TA) alternative splicing events (ASEs) based on high-coverage sequencing and stringent filtering, and also identified 8 differentially expressed splicing factors (SFs). The TA ASEs occurred in genes primarily involved in cytoskeletal organization. We constructed a correlative network between TA ASE splicing ratios and SF expression, replicated it in independent gastric cancer data from The Cancer Genome Atlas and experimentally validated it by knockdown of the nodal SFs (PTBP1, ESRP2 and MBNL1). Each SF knockdown drove splicing alterations in several corresponding TA ASEs and led to alterations in cellular migration consistent with the role of TA ASEs in cytoskeletal organization. We have therefore established a robust network of dysregulated splicing associated with tumor invasion in gastric cancer. Our work is a resource for identifying oncogenic splice forms, SFs and splicing-generated tumor antigens as biomarkers and therapeutic targets.
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Inhibition of platelet derived growth factor (PDGF) can increase the efficacy of other cancer therapeutics, but the cellular mechanism is incompletely understood. We examined the cellular effects on tumor vasculature of a novel DNA oligonucleotide aptamer (AX102) that selectively binds PDGF-B. Treatment with AX102 led to progressive reduction of pericytes, identified by PDGF receptor beta, NG2, desmin, or alpha-smooth muscle actin immunoreactivity, in Lewis lung carcinomas. The decrease ranged from 35% at 2 days, 63% at 7 days, to 85% at 28 days. Most tumor vessels that lacked pericytes at 7 days subsequently regressed. Overall tumor vascularity decreased 79% over 28 days, without a corresponding decrease in tumor size. Regression of pericytes and endothelial cells led to empty basement membrane sleeves, which were visible at 7 days, but only 54% remained at 28 days. PDGF-B inhibition had a less pronounced effect on pancreatic islet tumors in RIP-Tag2 transgenic mice, where pericytes decreased 47%, vascularity decreased 38%, and basement membrane sleeves decreased 21% over 28 days. Taken together, these findings show that inhibition of PDGF-B signaling can lead to regression of tumor vessels, but the magnitude is tumor specific and does not necessarily retard tumor growth. Loss of pericytes in tumors is an expected direct consequence of PDGF-B blockade, but reduced tumor vascularity is likely to be secondary to pericyte regression.
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Aptâmeros de Nucleotídeos/farmacologia , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Endotélio Vascular/patologia , Insulinoma/tratamento farmacológico , Pericitos/patologia , Proteínas Proto-Oncogênicas c-sis/antagonistas & inibidores , Células 3T3 , Animais , Carcinoma Pulmonar de Lewis/irrigação sanguínea , Carcinoma Pulmonar de Lewis/patologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Insulinoma/irrigação sanguínea , Insulinoma/patologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/patologia , Camundongos , Camundongos Transgênicos , Neovascularização Patológica/prevenção & controle , Pericitos/efeitos dos fármacos , Pericitos/metabolismo , Proteínas Proto-Oncogênicas c-sis/genética , Proteínas Proto-Oncogênicas c-sis/metabolismoRESUMO
BACKGROUND: Venous ulceration is a common and costly health-care issue worldwide, with poor healing rates greatly affecting patient quality of life. Compression bandaging has been shown to improve healing rates and reduce recurrence, but does not address the underlying cause, which is often superficial venous reflux. Surgical correction of the reflux reduces ulcer recurrence; however, the effect of early endovenous ablation of superficial venous reflux on ulcer healing is unclear. OBJECTIVES: To determine the clinical effectiveness and cost-effectiveness of compression therapy with early endovenous ablation of superficial venous reflux compared with compression therapy with deferred endovenous ablation in patients with venous ulceration. DESIGN: A pragmatic, two-arm, multicentre, parallel-group, open randomised controlled trial with a health economic evaluation. SETTING: Secondary care vascular centres in England. PARTICIPANTS: Patients aged ≥ 18 years with a venous leg ulcer of between 6 weeks' and 6 months' duration and an ankle-brachial pressure index of ≥ 0.8 who could tolerate compression and were deemed suitable for endovenous ablation of superficial venous reflux. INTERVENTIONS: Participants were randomised 1 : 1 to either early ablation (compression therapy and superficial endovenous ablation within 2 weeks of randomisation) or deferred ablation (compression therapy followed by endovenous ablation once the ulcer had healed). MAIN OUTCOME MEASURES: The primary outcome measure was time from randomisation to ulcer healing, confirmed by blinded assessment. Secondary outcomes included 24-week ulcer healing rates, ulcer-free time, clinical success (in addition to quality of life), costs and quality-adjusted life-years (QALYs). All analyses were performed on an intention-to-treat basis. RESULTS: A total of 450 participants were recruited (224 to early and 226 to deferred superficial endovenous ablation). Baseline characteristics were similar between the two groups. Time to ulcer healing was shorter in participants randomised to early superficial endovenous ablation than in those randomised to deferred ablation [hazard ratio 1.38, 95% confidence interval (CI) 1.13 to 1.68; p = 0.001]. Median time to ulcer healing was 56 (95% CI 49 to 66) days in the early ablation group and 82 (95% CI 69 to 92) days in the deferred ablation group. The ulcer healing rate at 24 weeks was 85.6% in the early ablation group, compared with 76.3% in the deferred ablation group. Median ulcer-free time was 306 [interquartile range (IQR) 240-328] days in the early ablation group and 278 (IQR 175-324) days in the deferred endovenous ablation group (p = 0.002). The most common complications of superficial endovenous ablation were pain and deep-vein thrombosis. Differences in repeated measures of Aberdeen Varicose Vein Questionnaire scores (p < 0.001), EuroQol-5 Dimensions index values (p = 0.03) and Short Form questionnaire-36 items body pain (p = 0.05) over the follow-up period were observed, in favour of early ablation. The mean difference in total costs between the early ablation and deferred ablation groups was £163 [standard error (SE) £318; p = 0.607]; however, there was a substantial and statistically significant gain in QALY over 1 year [mean difference between groups 0.041 (SE 0.017) QALYs; p = 0.017]. The incremental cost-effectiveness ratio of early ablation at 1 year was £3976 per QALY, with a high probability (89%) of being more cost-effective than deferred ablation at conventional UK decision-making thresholds (currently £20,000 per QALY). Sensitivity analyses using alternative statistical models give qualitatively similar results. LIMITATIONS: Only 7% of screened patients were recruited, treatment regimens varied significantly and technical success was assessed only in the early ablation group. CONCLUSIONS: Early endovenous ablation of superficial venous reflux, in addition to compression therapy and wound dressings, reduces the time to healing of venous leg ulcers, increases ulcer-free time and is highly likely to be cost-effective. FUTURE WORK: Longer-term follow-up is ongoing and will determine if early ablation will affect recurrence rates in the medium and long term. TRIAL REGISTRATION: Current Controlled Trials ISRCTN02335796. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 24. See the NIHR Journals Library website for further project information.
Venous leg ulcers are open wounds occurring on the legs of patients with venous disease. They are common, painful and distressing and reduce patient quality of life. Leg ulcers often result from valves in the leg veins not working properly. The valves normally force blood back up towards the heart; however, blood can flow backwards (reflux) when valves do not work properly, and this can cause swelling and ulceration. Compression therapy (wrapping bandages around the legs) has been shown to help ulcers heal, but it does not treat the underlying reflux problem with the veins. Newer, less invasive, techniques (known as endovenous ablation) have taken over from surgery to correct venous reflux and are more acceptable to patients as they can be performed quickly under local anaesthetic. The aim of the trial was to find out if treating patients with leg ulcers by early endovenous ablation (within 2 weeks) and standard compression therapy can increase ulcer healing compared with standard compression therapy and delayed endovenous ablation once the ulcer has healed. In total, 450 people agreed to take part in this study and were treated in 20 hospitals across England. Participants were randomly allocated to either early or delayed endovenous ablation and followed up for 12 months. The trial found that treating the veins early resulted in quicker ulcer healing than delaying treatment until the ulcer had healed. The trial also showed that participants had more time without an ulcer if the treatment was performed early rather than after ulcer healing. No safety issues with early intervention were identified. There is some evidence that quality of life was better in the early treatment group and that people in this group had less body pain. Treating ulcers early appears likely to be more cost-effective (i.e. a better use of NHS resources) than delayed treatment. Future work will focus on collecting longer-term follow-up data to find out if early endovenous ablation also reduces the chances of the ulcer coming back.
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Técnicas de Ablação , Bandagens Compressivas , Resultado do Tratamento , Úlcera Varicosa/cirurgia , Cicatrização , Adulto , Análise Custo-Benefício , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , RecidivaRESUMO
The specific down-regulation of gene expression in cells is a powerful method for elucidating a gene's function. A common method for suppressing gene expression is the elimination of mRNA by RNAi or antisense. Alternatively, oligonucleotide-derived aptamers have been used as protein-directed agents for the specific knock-down of both intracellular and extracellular protein activity. Protein-directed methods offer the advantage of more closely mimicking small molecule therapeutics' mechanism of activity. Furthermore, protein-directed methods may synergize with RNA-directed methods since the two methods attack gene expression at different levels. Here we have knocked down a well-characterized intracellular protein's activity, NFkappaB, by expressing either aptamers or small interfering RNAs (siRNAs). Both methods can diminish NFkappaB's activity to similar levels (from 29 to 64%). Interestingly, expression of both aptamers and siRNAs simultaneously, suppressed NFkappaB activity better than either method alone (up to 90%). These results demonstrate that the expression of intracellular aptamers is a viable alternative to siRNA knock-down. Furthermore, for the first time, we show that the use of aptamers and siRNA together can be the most effective way to achieve maximal knock-down of protein activity.
Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Subunidade p50 de NF-kappa B/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Aptâmeros de Nucleotídeos/química , Sequência de Bases , Linhagem Celular , Células HeLa , Humanos , Dados de Sequência Molecular , NF-kappa B/metabolismo , Subunidade p50 de NF-kappa B/genética , Subunidade p50 de NF-kappa B/metabolismoRESUMO
BACKGROUND: Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years. OBJECTIVE: To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention. DESIGN: Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2. SETTING: Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004. PARTICIPANTS: Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding. INTERVENTIONS: EVAR, OR or no intervention. MAIN OUTCOME MEASURES: The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness. RESULTS: In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality. LIMITATIONS: Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009. CONCLUSIONS: EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign. FUTURE WORK: To find easier ways to monitor sac expansion to trigger timely reintervention. TRIAL REGISTRATION: Current Controlled Trials ISRCTN55703451. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.
Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Procedimentos Endovasculares/economia , Procedimentos Endovasculares/métodos , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Análise Custo-Benefício , Procedimentos Endovasculares/efeitos adversos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Modelos de Riscos Proporcionais , Anos de Vida Ajustados por Qualidade de Vida , Avaliação da Tecnologia Biomédica , Tomografia Computadorizada por Raios X , Reino UnidoRESUMO
The standard decision rules of cost-effectiveness analysis either require the decision maker to set a threshold willingness to pay for additional health care or to set an overall fixed budget. In practice, neither are generally taken, but instead an arbitrary decision rule is followed that may not be consistent with the overall budget, lead to an allocation of resources that is less than optimal, and is unable to identify the program that should be displaced at the margin. Recent work has shown how mathematical programming can be used as a generalization of the standard decision rules. The authors extend the use of mathematical programming, first to incorporate more complex budgetary rules about when expenditure can be incurred, and show the opportunity loss, in terms of health benefit forgone, of each budgetary policy. Second, the authors demonstrate that indivisibility in a patient population can be regarded as essentially a concern for horizontal equity and represent this and other equity concerns as constraints in the program. Third, the authors estimate the different opportunity costs of a range of equity concerns applied to particular patient populations, and when imposed on all patient populations. They apply this framework of analysis to a realistic and policy-relevant problem.
Assuntos
Orçamentos , Modelos Econométricos , Alocação de Recursos/economia , Eficiência Organizacional , Gastos em Saúde , Política de Saúde/economia , Humanos , Anos de Vida Ajustados por Qualidade de VidaRESUMO
Achieving robust cancer-specific lethality is the ultimate clinical goal. Here, we identify a compound with dual-inhibitory properties, named a131, that selectively kills cancer cells, while protecting normal cells. Through an unbiased CETSA screen, we identify the PIP4K lipid kinases as the target of a131. Ablation of the PIP4Ks generates a phenocopy of the pharmacological effects of PIP4K inhibition by a131. Notably, PIP4Ks inhibition by a131 causes reversible growth arrest in normal cells by transcriptionally upregulating PIK3IP1, a suppressor of the PI3K/Akt/mTOR pathway. Strikingly, Ras activation overrides a131-induced PIK3IP1 upregulation and activates the PI3K/Akt/mTOR pathway. Consequently, Ras-transformed cells override a131-induced growth arrest and enter mitosis where a131's ability to de-cluster supernumerary centrosomes in cancer cells eliminates Ras-activated cells through mitotic catastrophe. Our discovery of drugs with a dual-inhibitory mechanism provides a unique pharmacological strategy against cancer and evidence of cross-activation between the Ras/Raf/MEK/ERK and PI3K/AKT/mTOR pathways via a Ras˧PIK3IP1˧PI3K signaling network.
Assuntos
Acrilonitrila/análogos & derivados , Indóis/farmacologia , Isoquinolinas/farmacologia , Proteínas de Membrana/metabolismo , Mitose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Acrilonitrila/farmacologia , Acrilonitrila/uso terapêutico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Indóis/uso terapêutico , Peptídeos e Proteínas de Sinalização Intracelular , Isoquinolinas/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Inibidores de Proteínas Quinases/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/metabolismoRESUMO
Aptamers (protein binding oligonucleotides) have potential as a new class of targeted therapeutics. For applications requiring chronic systemic administration, aptamers must achieve high-affinity target binding while simultaneously retaining high in vivo stability, tolerability, and ease of chemical synthesis. To this end, we describe a method for generating aptamers composed entirely of 2'-O-methyl nucleotides (mRmY). We present conditions under which 2'-O-methyl transcripts can be generated directly and use these conditions to select a fully 2'-O-methyl aptamer from a library of 3 x 10(15) unique 2'-O-methyl transcripts. This aptamer, ARC245, is 23 nucleotides in length, binds to vascular endothelial growth factor (VEGF) with a Kd of 2 nM, and inhibits VEGF activity in cellular assays. Notably, ARC245 is so stable that degradation cannot be detected after 96 hr in plasma at 37 degrees C or after autoclaving at 125 degrees C. We believe ARC245 has considerable potential as an antiangiogenesis therapeutic.
Assuntos
Oligonucleotídeos/farmacologia , Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/química , Inibidores da Angiogênese/metabolismo , Inibidores da Angiogênese/farmacologia , Animais , RNA Polimerases Dirigidas por DNA/metabolismo , Endotélio Vascular/efeitos dos fármacos , Biblioteca Gênica , Humanos , Hidrólise , Camundongos , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Fatores de Tempo , Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Conventional wisdom holds that methylation of RTKs should be restricted to intracellular sites. Alterations--such as deletion, mutation, and proteolytic cleavage events--to the extracellular ligand binding and dimer interface domains of the EGFR can induce EGFR dimer formation, leading to aberrant receptor activation and oncogenic activity. Recently, the extracellular domain of EGFR was also shown to be methylated, suggesting that posttranslational protein methylation events directed to the extracellular dimer interface provide another mechanism to regulate the EGFR activation state by modulating receptor dimerization. Critically, these methylation events abrogate response to conformation-specific therapeutic antibodies such as cetuximab. In this issue of the JCI, Liao et al. investigate the role of protein arginine methyltransferase I (PRMT1) in regulating EGFR function in colorectal cancer. The authors provide evidence that methylation of R198 and R200 within the dimer interface enhances growth factor ligand binding and cetuximab resistance through induction and stabilization of the active EGFR dimer conformation. Delineation of these and other subtleties involved in oncogenic RTK activation and their response to targeted therapies should facilitate the development of improved antibody-based treatments.