RESUMEN
OBJECTIVE: Hirschsprung disease (HSCR) is a severe congenital disorder affecting 1:5000 live births. HSCR results from the failure of enteric nervous system (ENS) progenitors to fully colonise the gastrointestinal tract during embryonic development. This leads to aganglionosis in the distal bowel, resulting in disrupted motor activity and impaired peristalsis. Currently, the only viable treatment option is surgical resection of the aganglionic bowel. However, patients frequently suffer debilitating, lifelong symptoms, with multiple surgical procedures often necessary. Hence, alternative treatment options are crucial. An attractive strategy involves the transplantation of ENS progenitors generated from human pluripotent stem cells (hPSCs). DESIGN: ENS progenitors were generated from hPSCs using an accelerated protocol and characterised, in detail, through a combination of single-cell RNA sequencing, protein expression analysis and calcium imaging. We tested ENS progenitors' capacity to integrate and affect functional responses in HSCR colon, after ex vivo transplantation to organotypically cultured patient-derived colonic tissue, using organ bath contractility. RESULTS: We found that our protocol consistently gives rise to high yields of a cell population exhibiting transcriptional and functional hallmarks of early ENS progenitors. Following transplantation, hPSC-derived ENS progenitors integrate, migrate and form neurons/glia within explanted human HSCR colon samples. Importantly, the transplanted HSCR tissue displayed significantly increased basal contractile activity and increased responses to electrical stimulation compared with control tissue. CONCLUSION: Our findings demonstrate, for the first time, the potential of hPSC-derived ENS progenitors to repopulate and increase functional responses in human HSCR patient colonic tissue.
Asunto(s)
Colon , Sistema Nervioso Entérico , Enfermedad de Hirschsprung , Enfermedad de Hirschsprung/cirugía , Enfermedad de Hirschsprung/terapia , Humanos , Células Madre Pluripotentes , Trasplante de Células Madre/métodos , Diferenciación CelularRESUMEN
Neuroepithelial cells balance tissue growth requirement with the morphogenetic imperative of closing the neural tube. They apically constrict to generate mechanical forces which elevate the neural folds, but are thought to apically dilate during mitosis. However, we previously reported that mitotic neuroepithelial cells in the mouse posterior neuropore have smaller apical surfaces than non-mitotic cells. Here, we document progressive apical enrichment of non-muscle myosin-II in mitotic, but not non-mitotic, neuroepithelial cells with smaller apical areas. Live-imaging of the chick posterior neuropore confirms apical constriction synchronised with mitosis, reaching maximal constriction by anaphase, before division and re-dilation. Mitotic apical constriction amplitude is significantly greater than interphase constrictions. To investigate conservation in humans, we characterised early stages of iPSC differentiation through dual SMAD-inhibition to robustly produce pseudostratified neuroepithelia with apically enriched actomyosin. These cultured neuroepithelial cells achieve an equivalent apical area to those in mouse embryos. iPSC-derived neuroepithelial cells have large apical areas in G2 which constrict in M phase and retain this constriction in G1/S. Given that this differentiation method produces anterior neural identities, we studied the anterior neuroepithelium of the elevating mouse mid-brain neural tube. Instead of constricting, mid-brain mitotic neuroepithelial cells have larger apical areas than interphase cells. Tissue geometry differs between the apically convex early midbrain and flat posterior neuropore. Culturing human neuroepithelia on equivalently convex surfaces prevents mitotic apical constriction. Thus, neuroepithelial cells undergo high-amplitude apical constriction synchronised with cell cycle progression but the timing of their constriction if influenced by tissue geometry.
Asunto(s)
Mitosis , Sistema Nervioso , Humanos , Animales , Ratones , Constricción , Ciclo Celular , Diferenciación Celular/fisiologíaRESUMEN
Digestive Chagas disease (DCD) is an enteric neuropathy caused by Trypanosoma cruzi infection. The mechanism of pathogenesis is poorly understood and the lack of a robust, predictive animal model has held back research. We screened a series of mouse models using gastrointestinal tracer assays and in vivo infection imaging systems to discover a subset exhibiting chronic digestive transit dysfunction and significant retention of faeces in both sated and fasted conditions. The colon was a specific site of both tissue parasite persistence, delayed transit and dramatic loss of myenteric neurons as revealed by whole-mount immunofluorescence analysis. DCD mice therefore recapitulated key clinical manifestations of human disease. We also exploited dual reporter transgenic parasites to home in on locations of rare chronic infection foci in the colon by ex vivo bioluminescence imaging and then used fluorescence imaging in tissue microdomains to reveal co-localisation of infection and enteric nervous system lesions. This indicates that long-term T. cruzi-host interactions in the colon drive DCD pathogenesis, suggesting that the efficacy of anti-parasitic chemotherapy against chronic disease progression warrants further pre-clinical investigation.
Asunto(s)
Enfermedad de Chagas/complicaciones , Modelos Animales de Enfermedad , Tracto Gastrointestinal/parasitología , Seudoobstrucción Intestinal/patología , Trypanosoma cruzi/patogenicidad , Animales , Enfermedad de Chagas/parasitología , Enfermedad Crónica , Femenino , Seudoobstrucción Intestinal/etiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones SCIDRESUMEN
AIMS: This study aims to determine whether intraoperative intravenous (IV) tranexamic acid (TXA) affects blood loss following the surgical management of femoral fragility fractures (FFF). METHODS: This was a single centre (university teaching hospital) non-randomised case-control study. There were 361 consecutive patients with FFF admitted over a 4-month period were included (mean age 81.4yrs; mean BMI 23.5; 73.7% female). Patient demographics, comorbidities, preoperative anticoagulation use, surgical management, intravenous TXA use, perioperative haemoglobin (Hb) and haematocrit, and requirement for blood transfusion were recorded. The primary outcome was postoperative blood transfusion requirement. Secondary outcomes included postoperative day one calculated blood loss (CBL) (using the Nadler and Gross formulae) and fall in Hb (percentage) from preoperative levels; and the incidence of thrombotic events and mortality up to 30 days. RESULTS: Groups were well matched in terms of patient demographics, comorbidities, preoperative anticoagulation use, injury types and surgical management. Intravenous TXA 1 g given at the beginning of surgery at the discretion of the operating team: 178 (49%) received TXA and 183 (51%) did not. The requirement for postoperative blood transfusion was significantly less in the TXA group: 15/178 (8.4%) compared to 58/183 (31.7%) (p < 0.001; Chi square). TXA significantly reduced both the percentage fall in Hb (mean difference 4.3%, p < 0.001) and the CBL (mean difference -222 ml, p < 0.001). There was no difference in VTE (2 vs 1, p = 0.620) or other thrombotic events (2 vs 0, p = 0.244) between groups. CONCLUSION: 1 g of intraoperative intravenous TXA during the surgical management of FFF was associated with reduced rate of transfusion, CBL and the percentage drop in HB. The use of TXA in this study was not randomised, so there could be un-quantifiable bias in the patient selection.
Asunto(s)
Fracturas del Fémur , Ácido Tranexámico , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Administración Intravenosa , Anticoagulantes , Pérdida de Sangre Quirúrgica/prevención & control , Transfusión Sanguínea , Estudios de Casos y Controles , Hospitales de EnseñanzaRESUMEN
BACKGROUND & AIMS: The enteric nervous system (ENS) is the largest branch of the peripheral nervous system, comprising complex networks of neurons and glia, which are present throughout the gastrointestinal tract. Although development of a fully functional ENS is required for gastrointestinal motility, little is known about the ontogeny of ENS function in humans. We studied the development of neuronal subtypes and the emergence of evoked electrical activity in the developing human ENS. METHODS: Human fetal gut samples (obtained via the MRC-Wellcome Trust Human Developmental Biology Resource-UK) were characterized by immunohistochemistry, calcium imaging, RNA sequencing, and quantitative real-time polymerase chain reaction analyses. RESULTS: Human fetal colon samples have dense neuronal networks at the level of the myenteric plexus by embryonic week (EW) 12, with expression of excitatory neurotransmitter and synaptic markers. By contrast, markers of inhibitory neurotransmitters were not observed until EW14. Electrical train stimulation of internodal strands did not evoke activity in the ENS of EW12 or EW14 tissues. However, compound calcium activation was observed at EW16, which was blocked by the addition of 1 µmol/L tetrodotoxin. Expression analyses showed that this activity was coincident with increases in expression of genes encoding proteins involved in neurotransmission and action potential generation. CONCLUSIONS: In analyses of human fetal intestinal samples, we followed development of neuronal diversity, electrical excitability, and network formation in the ENS. These processes are required to establish the functional enteric circuitry. Further studies could increase our understanding of the pathogenesis of a range of congenital enteric neuropathies.
Asunto(s)
Colon/inervación , Sistema Nervioso Entérico/fisiología , Potenciales Evocados , Red Nerviosa/fisiología , Neurogénesis , Neuronas/fisiología , Señalización del Calcio , Colon/embriología , Estimulación Eléctrica , Sistema Nervioso Entérico/efectos de los fármacos , Sistema Nervioso Entérico/embriología , Potenciales Evocados/efectos de los fármacos , Femenino , Regulación del Desarrollo de la Expresión Génica , Edad Gestacional , Humanos , Red Nerviosa/efectos de los fármacos , Red Nerviosa/embriología , Neurogénesis/efectos de los fármacos , Neurogénesis/genética , Neuronas/efectos de los fármacos , Neurotransmisores/farmacología , Fenotipo , Embarazo , Segundo Trimestre del Embarazo , Transmisión SinápticaRESUMEN
Current methods to replace damaged upper airway epithelium with exogenous cells are limited. Existing strategies use grafts that lack mucociliary function, leading to infection and the retention of secretions and keratin debris. Strategies that regenerate airway epithelium with mucociliary function are clearly desirable and would enable new treatments for complex airway disease.Here, we investigated the influence of the extracellular matrix (ECM) on airway epithelial cell adherence, proliferation and mucociliary function in the context of bioengineered mucosal grafts. In vitro, primary human bronchial epithelial cells (HBECs) adhered most readily to collagen IV. Biological, biomimetic and synthetic scaffolds were compared in terms of their ECM protein content and airway epithelial cell adherence.Collagen IV and laminin were preserved on the surface of decellularised dermis and epithelial cell attachment to decellularised dermis was greater than to the biomimetic or synthetic alternatives tested. Blocking epithelial integrin α2 led to decreased adherence to collagen IV and to decellularised dermis scaffolds. At air-liquid interface (ALI), bronchial epithelial cells cultured on decellularised dermis scaffolds formed a differentiated respiratory epithelium with mucociliary function. Using in vivo chick chorioallantoic membrane (CAM), rabbit airway and immunocompromised mouse models, we showed short-term preservation of the cell layer following transplantation.Our results demonstrate the feasibility of generating HBEC grafts on clinically applicable decellularised dermis scaffolds and identify matrix proteins and integrins important for this process. The long-term survivability of pre-differentiated epithelia and the relative merits of this approach against transplanting basal cells should be assessed further in pre-clinical airway transplantation models.
Asunto(s)
Colágeno , Matriz Extracelular , Laminina , Mucosa Respiratoria , Andamios del Tejido , Animales , Bronquios , Células Cultivadas , Células Epiteliales , Humanos , ConejosRESUMEN
AIMS AND OBJECTIVES: Children suffering from intestinal failure (IF) endure considerable morbidity and overall have poor survival rates, complicated by the shortage of organs available for transplantation. Therefore, new therapeutic approaches are pivotal if outcomes are to be improved. Over the past years, tissue engineering (TE) has emerged as a possible alternative treatment for many congenital and acquired conditions. TE aims at creating bioengineered organs by means of combining scaffolds with appropriate cell types, which in the intestine are organised within a multilayer structure. In order to generate functional intestine, this cellular diversity and organisation will need to be recreated. While the cells for the epithelial, neural and vascular compartments have been well defined, so far, less attention has been put on the muscular compartment. More recently, mesoangioblasts (MABs) have been identified as a novel source for tissue regeneration since they are able to give rise to vascular and other mesodermal derivatives. To date MABs have not been successfully isolated from intestinal tissue. Therefore, our aim was to demonstrate the possibility of isolating MABs from adult mouse small intestine. MATERIALS AND METHODS: All experiments were carried out using small intestinal tissues from C57BL/6J mice. We applied an established protocol for MAB isolation from the isolated neuromuscular layer of the small intestine. Cultured cells were stained for Ki67 to assess proliferation rates as well as for a panel of pericyte markers to determine their phenotype. RESULTS: Cells were successfully isolated from gut biopsies. Cultured cells showed good proliferative capacity and positivity for at least three pericytes markers found in vessels of the gut neuromuscular wall: neuron-glial antigen 2, alkaline phosphatase and platelet-derived growth factor ß. CONCLUSION: This proof-of-principle study lays the foundation for further characterization of MABs as a possible cell source for intestinal smooth muscle regeneration and TE.
Asunto(s)
Mesodermo/citología , Pericitos/citología , Ingeniería de Tejidos/métodos , Animales , Biomarcadores/metabolismo , Diferenciación Celular/fisiología , Células Cultivadas , Humanos , Mesodermo/metabolismo , Ratones , Ratones Endogámicos C57BL , Modelos Animales , Pericitos/metabolismoRESUMEN
Spinal cord injury (SCI) causes paralysis, multisystem impairment and reduced life expectancy, as yet with no cure. Stem cell therapy can potentially replace lost neurons, promote axonal regeneration and limit scar formation, but an optimal stem cell source has yet to be found. Enteric neural stem cells (ENSC) isolated from the enteric nervous system (ENS) of the gastrointestinal (GI) tract are an attractive source. Here, we used the chick embryo to assess the potential of ENSC to integrate within the developing spinal cord. In vitro, isolated ENSC formed extensive cell connections when co-cultured with spinal cord (SC)-derived cells. Further, qRT-PCR analysis revealed the presence of TuJ1+ neurons, S100+ glia and Sox10+ stem cells within ENSC neurospheres, as well as expression of key neuronal subtype genes, at levels comparable to SC tissue. Following ENSC transplantation to an ablated region of chick embryo SC, donor neurons were found up to 12 days later. These neurons formed bridging connections within the SC injury zone, aligned along the anterior/posterior axis, and were immunopositive for TuJ1. These data provide early proof of principle support for the use of ENSCs for SCI, and encourage further research into their potential for repair.
Asunto(s)
Células-Madre Neurales/trasplante , Regeneración de la Medula Espinal/fisiología , Médula Espinal , Trasplante de Células Madre/métodos , Animales , Embrión de Pollo , Sistema Nervioso Entérico/citologíaRESUMEN
BACKGROUND: The N-Myc Downstream-Regulated Gene (NDRG) family comprises four members that function in cellular processes like proliferation and differentiation. While NDRG1 and NDRG2 are extensively studied, knowledge regarding NDRG3 and NDRG4, despite its recognition as a well-established early-detection marker for colorectal cancer (Cologuard®), is sparse. SCOPE OF REVIEW: To summarize expression, biomarker potential and functional mechanisms of the NDRGs in the developing, mature and cancerous gut, we combine current literature and in silico analyses from the TCGA-database, GTEX Project, E14.5 mouse intestine and enteric neural crest cells, and an RNA-sequencing time-series of human embryonic colonic samples. MAJOR CONCLUSIONS: This study reveals that all members display a differential expression pattern in the gut and that NDRG1, NDRG2 and NDRG4 (1) can serve as biomarker for colorectal cancer and (2) have tumor suppressive properties mainly affecting cell proliferation and epithelial-mesenchymal transition. GENERAL SIGNIFICANCE: Similar effects of the NDRGs on the key-hallmarks of cancer, could implicate analogous functions in other tissue/cancer types.
Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Transición Epitelial-Mesenquimal , Neoplasias Gastrointestinales/patología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Musculares/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Simulación por Computador , Neoplasias Gastrointestinales/metabolismo , Humanos , Literatura de Revisión como AsuntoRESUMEN
Over the last 20 years, there has been increasing focus on the development of novel stem cell based therapies for the treatment of disorders and diseases affecting the enteric nervous system (ENS) of the gastrointestinal tract (so-called enteric neuropathies). Here, the idea is that ENS progenitor/stem cells could be transplanted into the gut wall to replace the damaged or absent neurons and glia of the ENS. This White Paper sets out experts' views on the commonly used methods and approaches to identify, isolate, purify, expand and optimize ENS stem cells, transplant them into the bowel, and assess transplant success, including restoration of gut function. We also highlight obstacles that must be overcome in order to progress from successful preclinical studies in animal models to ENS stem cell therapies in the clinic.
Asunto(s)
Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Sistema Nervioso Entérico/patología , Tracto Gastrointestinal/patología , Enfermedad de Hirschsprung/terapia , Seudoobstrucción Intestinal/terapia , Células-Madre Neurales/trasplante , Trasplante de Células Madre , Animales , Modelos Animales de Enfermedad , Tracto Gastrointestinal/inervación , Guías como Asunto , Enfermedad de Hirschsprung/patología , Humanos , Seudoobstrucción Intestinal/patologíaRESUMEN
OBJECTIVES: As workload increases, surgical care for patients with bone metastases is increasingly decentralised, with a shift in management away from primary bone tumour units to local centres. We must ensure that patients have similar outcomes regardless of where they receive their treatment. The aim was to develop and validate a set of quality outcome indicators (QOIs) to evaluate treatment success for patients undergoing surgery for bone metastases. METHODS: Outcome recommendations were adapted from the literature and field tested in a retrospective patient cohort to determine feasibility. The provisional outcome indicators were assessed during a modified RAND/Delphi consensus process by a group of patients, relatives and healthcare professionals with validated targets added. RESULTS: 1534 articles were reviewed. 38 quality objectives were extracted and assessed for feasibility using clinical records for 117 patients. 28 provisional outcome indicators proceeded to expert consensus and were reviewed by a group of 22 panellists including 10 patients and 4 relatives/carers. After two rounds, 15 QOIs were generated, with validated targets based on expert consensus. These included specific statements such as 'surgery improves pain and reduces the need for morphine, target: at follow-up, pain is documented in 80% of individuals and 50% of these have reduced need for morphine'. CONCLUSIONS: The published evidence and guidelines were adapted into a set of outcome indicators validated by patients, their family/carers and healthcare professionals. These can be used to compare care between centres and identify units of excellence in maximising good outcome after surgery for bone metastases.
RESUMEN
Digestive Chagas disease (DCD) is an enteric neuropathy caused by Trypanosoma cruzi infection. There is a lack of evidence on the mechanism of pathogenesis and rationales for treatment. We used a female C3H/HeN mouse model that recapitulates key clinical manifestations to study how infection dynamics shape DCD pathology and the impact of treatment with the front-line, anti-parasitic drug benznidazole. Curative treatment 6 weeks post-infection resulted in sustained recovery of gastrointestinal transit function, whereas treatment failure led to infection relapse and gradual return of DCD symptoms. Neuro/immune gene expression patterns shifted from chronic inflammation to a tissue repair profile after cure, accompanied by increased cellular proliferation, glial cell marker expression and recovery of neuronal density in the myenteric plexus. Delaying treatment until 24 weeks post-infection led to partial reversal of DCD, suggesting the accumulation of permanent tissue damage over the course of chronic infection. Our study shows that murine DCD pathogenesis is sustained by chronic T. cruzi infection and is not an inevitable consequence of acute stage denervation. The risk of irreversible enteric neuromuscular tissue damage and dysfunction developing highlights the importance of prompt diagnosis and treatment. These findings support the concept of treating asymptomatic, T. cruzi-infected individuals with benznidazole to prevent DCD development.
Asunto(s)
Enfermedad de Chagas , Modelos Animales de Enfermedad , Sistema Nervioso Entérico , Ratones Endogámicos C3H , Nitroimidazoles , Tripanocidas , Trypanosoma cruzi , Animales , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad de Chagas/parasitología , Femenino , Tripanocidas/farmacología , Tripanocidas/uso terapéutico , Nitroimidazoles/farmacología , Nitroimidazoles/uso terapéutico , Trypanosoma cruzi/efectos de los fármacos , Ratones , Sistema Nervioso Entérico/efectos de los fármacos , Regeneración Nerviosa/efectos de los fármacosRESUMEN
BACKGROUND AND PURPOSE: Symptomatic arrhythmia is common following radiotherapy for non-small cell lung cancer (NSCLC), frequently resulting in morbidity and hospitalization. Modern treatment planning technology theoretically allows sparing of cardiac substructures. Atrial fibrillation (AF) comprises the majority of post-radiotherapy arrhythmias, but efforts to prevent this cardiotoxicity have been limited as the causative cardiac substructure is not known. In this study we investigated if incidental radiation dose to the pulmonary veins (PVs) is associated with AF. MATERIAL AND METHODS: A single-centre study of patients completing contemporary (chemo)radiation for NSCLC, with modern planning techniques. Oncology, cardiology and death records were examined, and AF events were verified by a cardiologist. Cardiac substructures were contoured on planning scans for retrospective dose analysis. RESULTS: In 420 eligible patients with NSCLC treated with intensity-modulated (70%) or 3D-conformal (30%) radiotherapy with a median OS of 21.8 months (IQR 10.8-35.1), there were 26 cases of new AF (6%). All cases were grade 3 except two cases of grade 4. Dose metrics for both the left (V55) and right (V10) PVs were associated with the incidence of new AF. Metrics remained statistically significant after accounting for the competing risk of death and cardiovascular covariables for both the left (HR 1.02, 95%CI 1.00-1.03, p = 0.005) and right (HR 1.01 (95%CI 1.00-1.02, p = 0.033) PVs. CONCLUSION: Radiation dose to the PVs during treatment of NSCLC was associated with the onset of AF. Actively sparing the PVs during treatment planning could reduce the incidence of AF during follow-up, and screening for AF may be warranted for select cases.
Asunto(s)
Fibrilación Atrial , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Venas Pulmonares , Humanos , Fibrilación Atrial/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Estudios Retrospectivos , Neoplasias Pulmonares/radioterapia , Resultado del TratamientoRESUMEN
The development of a 3D printed sensor for direct incorporation within stoma pouches is described. Laser induced graphene scribed on either side of polyimide film served as the basis of a 2 electrode configuration that could be integrated within a disposable pouch sensor for the periodic monitoring of ileostomy fluid pH. The graphene sensors were characterised using electron microscopy, Raman spectroscopy, DekTak profilometry with the electrochemical properties investigated using both cyclic and square wave voltammetry. Adsorbed riboflavin was employed as a biocompatible redox probe for the voltammetric measurement of pH. The variation in peak position with pH was found to be linear over pH 3-8 with a sub Nernstian response (43 mV/pH). The adsorbed probe was found to be reversible and exhibited minimal leaching through repeated scanning. The performance of the system was assessed in a heterogeneous bacterial fermentation mixture simulating ileostomy fluid with the pH recorded before and after 96 h incubation. The peak profile in the bacterial medium provided an unambiguous signal free from interference with the calculated pH before and after incubation (pH 5.3 to 3.66) in good agreement with that obtained with commercial pH probes. Supplementary Information: The online version contains supplementary material available at 10.1007/s10853-023-08881-x.
RESUMEN
INTRODUCTION: Radiation cardiotoxicity is a dose-limiting toxicity and major survivorship issue for patients with non-small cell lung cancer (NSCLC) completing curative-intent radiotherapy, however patients' cardiovascular baseline is not routinely optimised prior to treatment. In this study we examined the impact of statin therapy on overall survival and post-radiotherapy cardiac events. METHODS: Patients treated between 2015-2020 at a regional center were identified. Clinical notes were interrogated for baseline patient, tumor and cardiac details, and both follow-up cancer control and cardiac events. Three cardiologists verified cardiac events. Radiotherapy planning scans were retrieved for application of validated deep learning-based autosegmentation. Pre-specified Cox regression analyses were generated with varying degrees of adjustment for overall survival. Fine and Gray regression for the risk of cardiac events, accounting for the competing risk of death and cardiac covariables was undertaken. RESULTS: Statin therapy was prescribed to 59% of the 478 included patients. The majority (88%) of patients not prescribed a statin had at least one indication for statin therapy according to cardiovascular guidelines. In total, 340 patients (71%) died and 79 patients (17%) experienced a cardiac event. High-intensity (HR 0.68, 95%CI 0.50-0.91, p = 0.012) and medium-intensity (HR 0.70, 95%CI 0.51-0.97, p = 0.033) statin therapy were associated with improved overall survival after adjustment for patient, cancer, treatment, response and cardiovascular clinical factors. There were no consistent differences in the rate or grade of cardiac events according to statin intensity. CONCLUSIONS: Statin therapy is associated with improved overall survival in patients receiving curative-intent radiotherapy for NSCLC, and there is evidence of a dose-response relationship. This study highlights the importance of a pre-treatment cardiovascular risk assessment in this cohort. Further studies are needed to examine if statin therapy is cardioprotective in patients undergoing treatment for NSCLC with considerable incidental cardiac radiation dose and a low baseline cardiac risk.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Cardiotoxicidad/etiología , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/radioterapia , Corazón , Estudios RetrospectivosRESUMEN
BACKGROUND AND PURPOSE: Cardiac arrhythmia is a recognised potential complication of thoracic radiotherapy, but the responsible cardiac substructures for arrhythmogenesis have not been identified. Arrhythmogenic tissue is commonly located in the pulmonary veins (PVs) of cardiology patients with arrhythmia, however these structures are not currently considered organs-at-risk during radiotherapy planning. A standardised approach to their delineation was developed and evaluated. MATERIALS AND METHODS: The gross and radiological anatomy relevant to atrial fibrillation was derived from cardiology and radiology literature by a multidisciplinary team. A region of interest and contouring instructions for radiotherapy computed tomography scans were iteratively developed and subsequently evaluated. Radiation oncologists (n = 5) and radiation technologists (n = 2) contoured the PVs on the four-dimensional planning datasets of five patients with locally advanced lung cancer treated with 1.8-2.75 Gy fractions. Contours were compared to reference contours agreed by the researchers using geometric and dosimetric parameters. RESULTS: The mean dose to the PVs was 35% prescription dose. Geometric and dosimetric similarity of the observer contours with reference contours was fair, with an overall mean Dice of 0.80 ± 0.02. The right superior PV (mean DSC 0.83 ± 0.02) had better overlap than the left (mean DSC 0.80 ± 0.03), but the inferior PVs were equivalent (mean DSC of 0.78). The mean difference in mean dose was 0.79 Gy ± 0.71 (1.46% ± 1.25). CONCLUSION: A PV atlas with multidisciplinary approval led to reproducible delineation for radiotherapy planning, supporting the utility of the atlas in future clinical radiotherapy cardiotoxicity research encompassing arrhythmia endpoints.
Asunto(s)
Venas Pulmonares , Humanos , Venas Pulmonares/diagnóstico por imagen , Planificación de la Radioterapia Asistida por Computador/métodos , Corazón , Tomografía Computarizada por Rayos X/métodos , Arritmias Cardíacas , Órganos en RiesgoRESUMEN
The mechanisms underlying slow-transit constipation (STC) are unclear. In 50% of patients with STC, some form of outlet obstruction has been reported; also an elongated colon has been linked to patients with STC. Our aims were 1) to develop a murine model of STC induced by partial outlet obstruction and 2) to determine whether this leads to colonic elongation and, consequently, activation of the inhibitory "occult reflex," which may contribute to STC in humans. Using a purse-string suture, we physically reduced the maximal anal sphincter opening in C57BL/6 mice. After 4 days, the mice were euthanized (acutely obstructed), the suture was removed (relieved), or the suture was removed and replaced repeatedly (chronically obstructed, over 24-31 days). In partially obstructed mice, we observed increased cyclooxygenase (COX)-2 levels in muscularis and mucosa, an elongated impacted large bowel, slowed transit, nonpropagating colonic migrating motor complexes (CMMCs), a lack of mucosal reflexes, a depolarized circular muscle with slow-wave activity due to a lack of spontaneous inhibitory junction potentials, muscle hypertrophy, and CMMCs in mucosa-free preparations. Elongation of the empty obstructed colon produced a pronounced occult reflex. Removal of the obstruction or addition of a COX-2 antagonist (in vitro and in vivo) restored membrane potential, spontaneous inhibitory junction potentials, CMMC propagation, and mucosal reflexes. We conclude that partial outlet obstruction increases COX-2 leading to a hyperexcitable colon. This hyperexcitability is largely due to suppression of only descending inhibitory nerve pathways by prostaglandins. The upregulation of motility is suppressed by the occult reflex activated by colonic elongation.
Asunto(s)
Estreñimiento , Motilidad Gastrointestinal , Intestino Grueso , Reflejo de Estiramiento/fisiología , Animales , Estreñimiento/etiología , Estreñimiento/metabolismo , Estreñimiento/fisiopatología , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa 2/farmacología , Modelos Animales de Enfermedad , Motilidad Gastrointestinal/efectos de los fármacos , Motilidad Gastrointestinal/fisiología , Humanos , Mucosa Intestinal/inervación , Mucosa Intestinal/metabolismo , Obstrucción Intestinal/complicaciones , Obstrucción Intestinal/metabolismo , Obstrucción Intestinal/fisiopatología , Intestino Grueso/metabolismo , Intestino Grueso/fisiopatología , Potenciales de la Membrana/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Músculo Liso/inervación , Músculo Liso/metabolismo , Plexo Mientérico/metabolismo , Complejo Mioeléctrico Migratorio/efectos de los fármacosRESUMEN
AIMS: Intravenous administration of adenosine after a pulmonary vein (PV) isolation procedure can unmask residual, so-called 'dormant', conduction that would otherwise remain unnoticed. Elimination of these dormant potentials is challenging because of the transient effect of adenosine, often requiring repeated injections. We tested the hypothesis that dipyridamole, a drug which inhibits adenosine deamination, can provoke longer-lasting unmasking of dormant conduction. METHODS AND RESULTS: In 191 patients with drug refractory paroxysmal atrial fibrillation, a bolus of 12-24 mg of adenosine was administered after all 764 PVs were isolated. In the case of transient dormant conduction, a short infusion of dipyridamole 50 mg was given and a bolus of adenosine was repeated. In all cases, re-isolation was attempted guided by the activation pattern in the PV on a circular mapping catheter. Duration of adenosine-induced dormant conduction before and after dipyridamole was recorded as the time between administration of adenosine and cessation of dormant conduction either spontaneously or by catheter ablation. Transient dormant conduction was re-established by a single bolus of adenosine in 24 of 191 patients (12.6%). Mean duration of adenosine-induced dormant conduction before dipyridamole was 13.1 ± 6.4 s, whereas it was significantly longer at 218.9 ± 165.6 s after dipyridamole (P < 0.0001). Eighteen of the 24 PVs were re-isolated by catheter ablation before spontaneous cessation of dormant conduction, and in 6 cases dormant conduction disappeared spontaneously before PV re-isolation was achieved. CONCLUSION: Dipyridamole significantly prolongs the effect of adenosine to unmask dormant conduction after PV isolation and may thus facilitate its elimination by catheter ablation.
Asunto(s)
Adenosina , Fibrilación Atrial/cirugía , Ablación por Catéter , Dipiridamol , Técnicas Electrofisiológicas Cardíacas , Venas Pulmonares/cirugía , Adenosina/administración & dosificación , Anciano , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Distribución de Chi-Cuadrado , Dipiridamol/administración & dosificación , Electrocardiografía , Femenino , Humanos , Infusiones Intravenosas , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Venas Pulmonares/fisiopatología , Factores de Tiempo , Resultado del TratamientoRESUMEN
The majority of the enteric nervous system is formed by vagal neural crest cells which enter the foregut and migrate rostrocaudally to colonise the entire length of the gastrointestinal tract. Absence of enteric ganglia from the distal colon are the hallmark of Hirschsprung disease, a congenital disorder characterised by severe intestinal dysmotility. Mutations in the receptor tyrosine kinase RET have been identified in approximately 50% of familial cases of Hirschsprung disease but the cellular processes misregulated in this condition remain unclear. By lineage tracing neural crest cells in mice homozygous for a knock-in allele of Ret (Ret51/51), we demonstrate that normal activity of this receptor is required in vivo for the migration of enteric nervous system progenitors throughout the gut. In mutant mice, progenitors of enteric neurons fail to colonise the distal colon, indicating that failure of colonisation of the distal intestine is a major contributing factor for the pathogenesis of Hirschsprung disease. Enteric nervous system progenitors in the ganglionic proximal guts of mutant mice are also characterised by reduced proliferation and differentiation. These findings suggest that the functional abnormalities in Hirschsprung disease result from a combination of colonic aganglionosis and deficits in neuronal circuitry of more proximal gut segments. The reduced neurogenesis in the gut of Ret51/51 mutants was reproduced in the multilineage enteric nervous system progenitors isolated from these animals. Correction of the molecular defects of such progenitors fully restored their neurogenic potential in culture. These observations enhance our understanding of the pathogenesis of Hirschsprung disease and highlight potential approaches for its treatment.
RESUMEN
AIM: The Edinburgh Trauma Triage clinic (TTC) is an established form of Virtual Fracture clinic (VFC) that permits the direct discharge of simple, isolated fractures from the Emergency Department (ED). Small, short-term cohort studies of similar systems have been published, but to detect low rates of complications requires a large study sample and longer-term follow-up. This study details the outcomes of all patients with injuries suitable for a direct discharge protocol over a four-year period, reviewed at a minimum of three years after attendance. PATIENTS: All TTC records between February 2014 and December 2017 were collated from a prospective database. Fractures of the radial head, little finger metacarpal, fifth metatarsal, toe phalanges and mallet finger injuries were included. TTC outcome, including any deviations from a well-established direct discharge protocol, were noted. All records were re-assessed at a minimum of 36 months after TTC triage (mean 54 months) to ascertain which injuries attended the trauma clinic after initial discharge. Reasons for attendance, the source of referral and any subsequent surgical procedures were identified. RESULTS: There were 6688 patients with fractures of the radial head (1861), little finger metacarpal (1621), fifth metatarsal (1916), toe phalanges (920) and mallet finger injuries (370). 298 (6%) patients were re-referred after direct discharge and attended trauma clinic at a mean time after injury of 11.9 weeks, of whom 11 (0.2%) underwent a surgical intervention. Serious adverse events, defined as those in which a patient may not have come to harm if early clinical review had been undertaken, occurred in 1 patient (0.01%). CONCLUSION: Intervention after direct discharge of simple pre-defined injuries of the elbow, hand and foot is low. Within a TTC system, patients with these injuries can be safely discharged without routine follow-up.