RESUMO
Realization of topological superconductors (TSCs) hosting Majorana fermions is a central challenge in condensed-matter physics. One approach is to use the superconducting proximity effect (SPE) in heterostructures, where a topological insulator contacted with a superconductor hosts an effective p-wave pairing by the penetration of Cooper pairs across the interface. However, this approach suffers a difficulty in accessing the topological interface buried deep beneath the surface. Here, we propose an alternative approach to realize topological superconductivity without SPE. In a Pb(111) thin film grown on TlBiSe2, we discover that the Dirac-cone state of substrate TlBiSe2 migrates to the top surface of Pb film and obtains an energy gap below the superconducting transition temperature of Pb. This suggests that a Bardeen-Cooper-Schrieffer superconductor is converted into a TSC by the topological proximity effect. Our discovery opens a route to manipulate topological superconducting properties of materials.
Assuntos
Cicatriz/imunologia , Doença de Crohn/tratamento farmacológico , Dermatoses Faciais/imunologia , Doenças Nasais/imunologia , Inibidores do Fator de Necrose Tumoral/efeitos adversos , Adulto , Cicatriz/induzido quimicamente , Cicatriz/diagnóstico , Doença de Crohn/imunologia , Dermatoses Faciais/induzido quimicamente , Dermatoses Faciais/complicações , Dermatoses Faciais/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Nasais/induzido quimicamente , Doenças Nasais/complicações , Doenças Nasais/diagnósticoRESUMO
BACKGROUND: Standard high-volume polyethylene glycol [PEG] bowel preparations [PEG-4L] are recommended for patients with inflammatory bowel disease [IBD] undergoing colonoscopy. However, low-volume preparations [≤2 L of active volume] are often used in clinical practice. The aim of this study was to evaluate the efficacy, tolerability, and safety of the various bowel preparations for patients with IBD, including low-volume preparations. METHODS: We conducted a French prospective multicentre observational study over a period of 1 month. Patients aged 18-75 years with IBD with an indication of colonoscopy independent of the study were enrolled. The choice of the preparation was left to the investigators, as per their usual protocol. The patients' characteristics, disease, and colonoscopy characteristics were recorded, and they were given self-reported questionnaires. RESULTS: Twenty-five public and private hospitals enrolled 278 patients. Among them, 46 had a disease flare and 41 had bowel stenoses. Bowel preparations for colonoscopy were as follows: 42% received PEG-2L, 29% received sodium picosulfate [Pico], 15% received PEG-4L, and 14% had other preparations. The preparation did not reach the Boston's score efficacy outcome in the PEG-4L group in 51.2% of the patients [p = 0.0011]. The preparation intake was complete for 59.5% in the PEG-4L group, compared with 82.9% in the PEG-2L group and 93.8% in the Pico group [p < 0.0001]. Tolerability, as assessed by the patients' VAS, was significantly better for both Pico and PEG-2L compared with PEG-4L, and better for Pico compared with PEG-2L [p = 0.008; p = 0.0003]. In multivariate analyses, low-volume preparations were independent factors of efficacy and tolerability. Adverse events occurred in 4.3% of the patients. CONCLUSIONS: Preparations with PEG-2L and Pico were equally safe, with better efficacy and tolerability outcomes compared with PEG-4L preparations. The best efficacy/tolerance/safety profile was achieved with the Pico preparation.
Assuntos
Catárticos , Colonoscopia/métodos , Doenças Inflamatórias Intestinais/diagnóstico , Polietilenoglicóis , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Catárticos/administração & dosagem , Catárticos/efeitos adversos , Citratos/administração & dosagem , Citratos/efeitos adversos , Colite Ulcerativa/diagnóstico , Colonoscopia/efeitos adversos , Doença de Crohn/diagnóstico , Feminino , Humanos , Doenças Inflamatórias Intestinais/patologia , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/efeitos adversos , Picolinas/administração & dosagem , Picolinas/efeitos adversos , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/efeitos adversos , Estudos Prospectivos , Adulto JovemRESUMO
BACKGROUND: Neuroplastic changes in the enteric nervous system (ENS) observed during IBD might participate in physiopathological processes. Vasoactive intestinal polypeptide has been shown to be involved in intestinal inflammation and barrier functions. We aimed to investigate the modulation of VIP expression in colonic biopsies of IBD patient, the ability of soluble factors from biopsies to reproduce in vitro these modulations and identify soluble factors responsible. METHODS: VIP and cytokines mRNA expressions were assessed in colonic biopsies of healthy subjects (HS) and IBD patients from inflamed (I) and non-inflamed areas (NI). Supernatants (SUP) of biopsies were applied to primary culture of ENS and VIP and cytokines mRNA expressions were assessed. The role of cytokines in SUP induced changes in VIP expression was evaluated. KEY RESULTS: VIP mRNA expression was lower in biopsies of patients with Crohn's disease (CD) than Ulcerative Colitis (UC) but unchanged as compared to HS. VIP mRNA and protein expression were lower in primary culture of ENS incubated with SUP-CD than with SUP-UC. Furthermore, in CD but not UC, SUP-I reduced VIP expression in the ENS as compared to SUP-NI. Next, IL-6 but not IL-5, IL-10, IL-17, IFN-γ or TNF-α reduced VIP expression in the ENS. Finally, in CD, SUP-I incubated with anti-IL-6 antibody increased VIP expression as compared to SUP-I alone. CONCLUSIONS & INFERENCES: Mucosal soluble factors from IBD induce VIP neuroplastic changes in the ENS. IL-6 was identified as a putative soluble factor responsible in part for changes in VIP expression in CD.
Assuntos
Colo/metabolismo , Doença de Crohn/metabolismo , Sistema Nervoso Entérico/metabolismo , Interleucina-6/metabolismo , Neurônios/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo , Adolescente , Adulto , Animais , Biópsia , Doença de Crohn/patologia , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cultura Primária de Células , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Adulto JovemRESUMO
Capsule endoscopy (CE) is a safe, non-invasive diagnostic tool to evaluate small bowel lesions. CE, like conventional endoscopy, can detect focal and small-ulcerated lesions along the entire length of the small bowel, which are not identified by other imaging techniques. Meta-analysis has shown that CE is better than any other radiological technique to detect small bowel lesions in patients with suspected or known Crohn's disease (CD). In unclassified colitis, CE is also useful in distinguishing CD and ulcerative colitis (UC). In established CD, CE may be used to detect post-operative recurrence, determine the extent of small bowel lesions and link ulcerated lesions with clinical symptoms. Although CE is well tolerated there is a theoretical risk of capsule impaction in general and in CD in particular. To avoid capsule impaction, a new option called the "patency capsule" is available especially in patients with symptoms suggesting small bowel obstruction. However, few data are available about this new device and its use in clinical practice needs to be clarified.
Assuntos
Endoscopia por Cápsula , Doenças Inflamatórias Intestinais/diagnóstico , Mucosa Intestinal/patologia , Algoritmos , Endoscopia por Cápsula/efeitos adversos , Endoscopia por Cápsula/métodos , Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , Diagnóstico Diferencial , Humanos , Doenças Inflamatórias Intestinais/terapia , Metanálise como Assunto , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de DoençaRESUMO
The synthesis of antiviral beta-chemokines has joined cytolysis as a potential mechanism for the control of HIV-1 infection by CD8(+) T cells. Recent evidence suggests that these two effector functions can diverge in some individuals infected with HIV-1; however, little is known about the CD8(+) T cell subsets in normal individuals that synthesize antiviral beta-chemokines. In this report, we have used mutliparameter flow cytometry to characterize the T cell subsets that secrete the antiviral beta-chemokine macrophage inflammatory protein (MIP)-1beta. These studies have shown: (i) CD8(+) cells are the predominant T cell subset that synthesizes MIP-1beta; (ii) MIP-1beta and IFN-gamma are synthesized congruently in most CD8(+) T cells; however, significant numbers of these cells synthesize only one of these effector molecules; (iii) approximately 60% of the CD8(+) T cells that synthesize MIP-1beta lack perforin; (iv) MIP-1beta is synthesized with approximately equal frequency by CD28(+) and CD28(-) subpopulations of CD8(+) T cells; (v) MIP-1beta is synthesized by three distinct CD8(+) T cell subsets defined by the expression of CD45R0 and CD62L; and (vi) MIP-1beta is not synthesized in short-term cultures of naive CD8(+) T cells. These results demonstrate substantial subset heterogeneity of MIP-1beta synthesis among CD8(+) T cells and suggest that these subsets should be evaluated as correlates of protective immunity against HIV-1.