Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Mol Microbiol ; 121(3): 543-564, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38148574

RESUMO

The transmission of malaria parasites to mosquitoes is dependent on the formation of gametocytes. Once fully matured, gametocytes are able to transform into gametes in the mosquito's midgut, a process accompanied with their egress from the enveloping erythrocyte. Gametocyte maturation and gametogenesis require a well-coordinated gene expression program that involves a wide spectrum of regulatory proteins, ranging from histone modifiers to transcription factors to RNA-binding proteins. Here, we investigated the role of the CCCH zinc finger protein MD3 in Plasmodium falciparum gametocytogenesis. MD3 was originally identified as an epigenetically regulated protein of immature gametocytes and recently shown to be involved in male development in a barcode-based screen in P. berghei. We report that MD3 is mainly present in the cytoplasm of immature male P. falciparum gametocytes. Parasites deficient of MD3 are impaired in gametocyte maturation and male gametocytogenesis. BioID analysis in combination with co-immunoprecipitation assays unveiled an interaction network of MD3 with RNA-binding proteins like PABP1 and ALBA3, with translational initiators, regulators and repressors like elF4G, PUF1, NOT1 and CITH, and with further regulators of gametocytogenesis, including ZNF4, MD1 and GD1. We conclude that MD3 is part of a regulator complex crucial for post-transcriptional fine-tuning of male gametocytogenesis.


Assuntos
Parasitos , Plasmodium falciparum , Animais , Masculino , Plasmodium falciparum/metabolismo , Parasitos/metabolismo , Histonas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Dedos de Zinco
2.
Gastrointest Endosc ; 98(5): 877-878, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37863579
3.
Minim Invasive Ther Allied Technol ; 32(3): 103-111, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36825622

RESUMO

INTRODUCTION: Argon plasma coagulation (APC) is an electrosurgical procedure used, among other indications, for treatment of dysplastic Barrett's mucosa. Homogeneous and safe application can be compromised by varying distances and suboptimal angle of the probe to the tissue. In this study, we present ArgoCap, a novel endoscopic device developed to facilitate endoluminal APC treatment. Objectives of this preclinical study were to assess feasibility and safety and to determine suitable APC settings. MATERIAL AND METHODS: One-hundred and thirty-two APC treatments of predefined areas using various APC settings were performed ex vivo in the opened porcine esophagus. Depth of thermal injury was assessed histologically. Feasibility of APC treatment in different locations was examined in 20 explanted porcine esophagi and in first in vivo porcine applications. RESULTS: APC treatment in all quadrants of the esophagus was feasible. Histologically, thermal effects involving the whole thickness of the mucosa were visible with all settings. APC with pulsed mode resulted in deep thermal damage with all power settings. No lesions of the muscular layer occurred using precise (E8, E9) and forced (10 W, 20 W) mode. CONCLUSIONS: Esophageal APC using ArgoCap is feasible and safe. The device has the potential to improve APC treatment of larger mucosal areas.


Assuntos
Coagulação com Plasma de Argônio , Esôfago de Barrett , Animais , Suínos , Esôfago de Barrett/patologia , Esôfago de Barrett/cirurgia , Estudos de Viabilidade , Fotocoagulação a Laser/métodos , Esofagoscopia/métodos
4.
Gastrointest Endosc ; 97(4): 780-789.e4, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36410447

RESUMO

BACKGROUND AND AIMS: Endoscopic full-thickness resection (eFTR) is emerging as a minimally invasive alternative to surgery for complex colorectal lesions. Previous studies have demonstrated favorable safety results; however, large studies representing a generalizable estimation of adverse events (AEs) are lacking. Our aim was to provide further insight in AEs after eFTR. METHODS: Data from all registered eFTR procedures in the German and Dutch colorectal full-thickness resection device registries between July 2015 and March 2021 were collected. Safety outcomes included immediate and late AEs. RESULTS: Of 1892 procedures, the overall AE rate was 11.3% (213/1892). No AE-related mortality occurred. Perforations occurred in 2.5% (47/1892) of all AEs, 57.4% (27/47) of immediate AEs, and 42.6% (20/47) of delayed AEs. Successful endoscopic closure was achieved in 29.8% of cases (13 immediate and 1 delayed), and antibiotic treatment was sufficient in 4.3% (2 delayed). The appendicitis rate for appendiceal lesions was 9.9% (13/131), and 46.2% (6/13) could be treated conservatively. The severe AE rate requiring surgery was 2.2% (42/1892), including delayed perforations in .9% (17/1892) and immediate perforations in .7% (13/1892). Delayed perforations occurred between days 1 and 10 (median, 2) after eFTR, and 58.8% (10/17) were located on the left side. Other severe AEs were appendicitis (.4%, 7/1892), luminal stenosis (.1%, 2/1892), delayed bleeding (.1%, 1/1892), pain after eFTR close to the dentate line (.1%, 1/1892), and grasper entrapment in the clip (.1%, 1/1892). CONCLUSIONS: Colorectal eFTR is a safe procedure with a low risk for severe AEs in everyday practice and without AE-related mortality. These results further support the position of eFTR as an established minimally invasive technique for complex colorectal lesions.


Assuntos
Apendicite , Neoplasias Colorretais , Ressecção Endoscópica de Mucosa , Humanos , Resultado do Tratamento , Estudos Retrospectivos , Endoscopia , Ressecção Endoscópica de Mucosa/métodos , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/patologia
5.
Endoscopy ; 55(5): 415-422, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36323331

RESUMO

BACKGROUND: Risk stratification and recommendation for surgery for intraductal papillary mucinous neoplasm (IPMN) are currently based on consensus guidelines. Risk stratification from presurgery histology is only potentially decisive owing to the low sensitivity of fine-needle aspiration. In this study, we developed and validated a deep learning-based method to distinguish between IPMN with low grade dysplasia and IPMN with high grade dysplasia/invasive carcinoma using endoscopic ultrasound (EUS) images. METHODS: For model training, we acquired a total of 3355 EUS images from 43 patients who underwent pancreatectomy from March 2015 to August 2021. All patients had histologically proven IPMN. We used transfer learning to fine-tune a convolutional neural network and to classify "low grade IPMN" from "high grade IPMN/invasive carcinoma." Our test set consisted of 1823 images from 27 patients, recruiting 11 patients retrospectively, 7 patients prospectively, and 9 patients externally. We compared our results with the prediction based on international consensus guidelines. RESULTS: Our approach could classify low grade from high grade/invasive carcinoma in the test set with an accuracy of 99.6 % (95 %CI 99.5 %-99.9 %). Our deep learning model achieved superior accuracy in prediction of the histological outcome compared with any individual guideline, which have accuracies between 51.8 % (95 %CI 31.9 %-71.3 %) and 70.4 % (95 %CI 49.8-86.2). CONCLUSION: This pilot study demonstrated that deep learning in IPMN-EUS images can predict the histological outcome with high accuracy.


Assuntos
Adenocarcinoma Mucinoso , Carcinoma Ductal Pancreático , Aprendizado Profundo , Neoplasias Intraductais Pancreáticas , Neoplasias Pancreáticas , Humanos , Carcinoma Ductal Pancreático/patologia , Estudos Retrospectivos , Neoplasias Intraductais Pancreáticas/diagnóstico por imagem , Projetos Piloto , Adenocarcinoma Mucinoso/patologia , Neoplasias Pancreáticas/patologia
6.
Surg Endosc ; 37(3): 1854-1862, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36253626

RESUMO

BACKGROUND: Surgery or transcatheter arterial embolization or are both considered as standard treatment of peptic ulcer bleeding (PUB) refractory to endoscopic hemostasis. Over-The-Scope clips (OTSC) have shown superiority to standard endoscopic treatment but a comparison with surgery has not been performed, yet. PATIENTS AND METHODS: In this retrospective, multicenter study, 103 patients treated with OTSC (n = 66) or surgery (n = 37) for refractory PUB in four tertiary care centers between 2009 and 2019 were analyzed. Primary endpoint was clinical success (successful hemostasis and no rebleeding within seven days). Secondary endpoints were adverse events, length of ICU-stay and in-hospital mortality. Univariable and multivariable regression models were performed to define predictive factors for allocation to surgical therapy and for mortality. RESULTS: Age, comorbidities, anticoagulation therapy, number of pretreatments, ulcer location, and Rockall-Score were similar in both groups. In the surgical group, there were significantly more patients in shock at rebleeding (78.1% vs. 43.9%; p = 0.002), larger ulcers (18.6 ± 7.4 mm vs. 23.0 ± 9.4 mm; p = 0.017) and more FIa bleedings (64.9% vs. 19.7%; p < 0.001) were detected. Clinical success was comparable (74.2% vs. 83.8%; p = 0.329). In the surgical group, length of ICU-stay (16.2 ± 18.0 days vs. 4.7 ± 6.6 days; p < 0.001), severe adverse events (70.3% vs. 4.5%; p < 0.001) and in-hospital mortality (35.1% vs. 9.1%; p = 0.003) were significantly higher. Multivariable analysis defined shock at rebleeding as the main predictor for allocation to surgical therapy (OR 4.063, 95%CI {1.496-11.033}, p = 0.006). Postsurgical adverse events were the main reason for the in-hospital mortality (OR 5.167, 95% CI {1.311-20.363}, p = 0.019). CONCLUSION: In this retrospective study, OTSC compared to surgical treatment showed comparable clinical success but was associated with shorter ICU-stay, less severe adverse events and lower in-hospital mortality.


Assuntos
Embolização Terapêutica , Hemostase Endoscópica , Úlcera Péptica , Humanos , Estudos Retrospectivos , Úlcera Péptica Hemorrágica/cirurgia , Recidiva , Resultado do Tratamento
7.
Dig Endosc ; 35(2): 232-242, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35997598

RESUMO

Endoscopic full-thickness resection (EFTR) using the full-thickness resection device (FTRD) is an integral part of diagnostic and therapeutic endoscopy. Since its market launch in Europe in 2014, its safety and effectiveness have been proven in numerous studies. Adaptations in design as well as new techniques, such as hybrid EFTR, expand the spectrum of the FTRD system. The following review is intended to provide an overview of the clinical application and current evidence of EFTR with the FTRD system.


Assuntos
Endoscopia , Humanos , Resultado do Tratamento , Europa (Continente) , Estudos Retrospectivos
8.
Gastrointest Endosc ; 96(1): 1-8, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35143814

RESUMO

BACKGROUND AND AIMS: Self-expandable metal stent (SEMS) placement is routinely performed in a variety of benign and malignant GI diseases. One of the most frequent adverse events after esophageal SEMS placement is stent migration. We evaluated a novel over-the-scope clip device (stentfix OTSC; Ovesco Endoscopy, Tuebingen, Germany) designed and approved for SEMS fixation. METHODS: This single-center retrospective observational cohort study was performed to analyze stent migration rates before and after availability of the stentfix OTSC device. A cohort of patients who consecutively underwent SEMS fixation with the stentfix OTSC system (SF cohort) was compared with an historical cohort of patients who did not receive stentfix OTSC fixation or any other stent fixation method (NF cohort) before the stentfix OTSC system became available. Outcome variables including technical success, adverse events and clinical success were analyzed. RESULTS: Seventy-seven patients (SF cohort, 26; NF cohort, 51) underwent esophageal SEMS implantation for malignant (69%) and benign (31%) conditions. The technical success rate of stent fixation was 100%, and no procedure-related adverse events were observed. The stent migration rate was significantly lower in the SF cohort compared with the NF cohort (8.3% vs 35.4%, P < .001), indicating a relative risk reduction of 76.5% associated with stentfix OTSC application. Stent implantation across the gastroesophageal junction was identified as a predictor of stent migration. CONCLUSIONS: In patients with benign or malignant gastroesophageal diseases, there was a significantly lower stent migration rate in patients managed with the stentfix OTSC system compared with those without stent fixation. The application was technically successful in all cases, and no adverse events related to clip application or removal were observed.


Assuntos
Stents Metálicos Autoexpansíveis , Instrumentos Cirúrgicos , Endoscopia Gastrointestinal/métodos , Humanos , Estudos Retrospectivos , Stents Metálicos Autoexpansíveis/efeitos adversos , Stents , Resultado do Tratamento
9.
VideoGIE ; 6(6): 250-251, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34141963

RESUMO

Video 1We present a case of a 76 year old patient undergoing holmium laser enucleation of an esophageal leiomyoma in endoscopic tunnel technique.

10.
Front Immunol ; 10: 1679, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428084

RESUMO

Inducing T cell responses by therapeutic vaccination requires appropriate activation of antigen presenting cells (APCs). The use of virus-like particles (VLPs) containing Toll-like receptor (TLR) ligands has demonstrated remarkable potential in activating APCs and modulating the immune response both for prophylactic vaccines as well as immunotherapy. Here, we employed VLPs associated to TLR ligands as tools to modulate cytotoxic response mediated by CD8+ T cells and provide further insight in the development of T cell-based immunotherapy. We have investigated the in vivo transcriptional signature in dendritic cells (DCs) from mice immunized with VLPs containing distinct classes of nucleic acid and correlated the expression patterns with the efficiency of induced T cell responses. We identified key pathways activated in DCs that are involved in the appropriated induction of T cell responses and show evidence for the modulatory effect of CCL2 in CD8+ T cells responses. These insights shed light on immune networks that are pivotal for the induction of potent cytotoxic T cell responses and identify key genes for appropriate DC activation and subsequent modulation of the adaptive immune response.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Receptores Toll-Like/imunologia , Transcrição Gênica/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Apresentação de Antígeno/imunologia , Quimiocina CCL2 , Imunização/métodos , Imunoterapia/métodos , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T Citotóxicos/imunologia , Vacinação/métodos
11.
Gastrointest Endosc ; 90(3): 540, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31439142
13.
Gastrointest Endosc ; 89(6): 1180-1189.e1, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30653939

RESUMO

BACKGROUND AND AIMS: Current international guidelines recommend endoscopic resection for T1 colorectal cancer (CRC) with low-risk histology features and oncologic resection for those at high risk of lymphatic metastasis. Exact risk stratification is therefore crucial to avoid under-treatment as well as over-treatment. Endoscopic full-thickness resection (EFTR) has shown to be effective for treatment of non-lifting benign lesions. In this multicenter, retrospective study we aimed to evaluate efficacy, safety, and clinical value of EFTR for early CRC. METHODS: Records of 1234 patients undergoing EFTR for various indications at 96 centers were screened for eligibility. A total of 156 patients with histologic evidence of adenocarcinoma were identified. This cohort included 64 cases undergoing EFTR after incomplete resection of a malignant polyp (group 1) and 92 non-lifting lesions (group 2). Endpoints of the study were: technical success, R0-resection, adverse events, and successful discrimination of high-risk versus low-risk tumors. RESULTS: Technical success was achieved in 144 out of 156 (92.3%). Mean procedural time was 42 minutes. R0 resection was achieved in 112 of 156 (71.8%). Subgroup analysis showed a R0 resection rate of 87.5% in Group 1 and 60.9% in Group 2 (P < .001). Severe procedure-related adverse events were recorded in 3.9% of patients. Discrimination between high-risk versus low-risk tumor was successful in 155 of 156 cases (99.3%). In Group 1, 84.1% were identified as low-risk lesions, whereas 16.3% in group 2 had low-risk features. In total, 53 patients (34%) underwent oncologic resection due to high-risk features whereas 98 patients (62%) were followed endoscopically. CONCLUSIONS: In early colorectal cancer, EFTR is technically feasible and safe. It allows exact histological risk stratification and can avoid surgery for low-risk lesions. Prospective studies are required to further define indications for EFTR in malignant colorectal lesions and to evaluate long-term outcome.


Assuntos
Adenocarcinoma/cirurgia , Colonoscopia/métodos , Neoplasias Colorretais/cirurgia , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Medição de Risco , Resultado do Tratamento
14.
Chemistry ; 23(11): 2628-2634, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-27925694

RESUMO

We synthesized a novel green-light-responsive tetra-ortho-isopropoxy-substituted azobenzene (ipAzo). Cis-ipAzo forms a strong host-guest complex with γ-cyclo dextrin (γ-CD) whereas trans-ipAzo binds weakly. This new photoresponsive host-guest interaction is reverse to the well-known azobenzene (Azo)/α-cyclodextrin (α-CD) complex, which is strong only between trans-Azo and α-CD. By combining the UV-light-responsive Azo/α-CD and green-light-responsive ipAzo/γ-CD host-guest complexes, a photoresponsive orthogonal supramolecular system is developed.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA