Suchergebnisse

Nisha A Shah, Dustin M Albert, Noah M Hall, Fouad J Moawad Department of Medicine, Gastroenterology Service, Walter Reed National Military Medical Center, Bethesda, MD, USA Abstract: Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated condition defined by symptoms of esophageal dysfunction and dense eosinophilic infiltration of the esophageal mucosa. Therapies consist of anti-eosinophilic medications and specialized diets aimed to decrease the progression of EoE and alleviate its symptoms, namely, dysphagia and food impaction. Assessing response to therapy remains challenging, as treatment end points are not well defined and currently consist of clinical, histologic, and endoscopic features. Newer validated measures may help standardize treatment end points. Emerging data support the use of maintenance therapy, which may reduce disease progression. Optimal dosages, delivery techniques, and duration of treatment need to be determined. When features of fibrostenosis develop, esophageal dilation is a safe and effective adjunctive strategy for improving symptoms. In EoE cases refractory to conventional treatments, newer therapies targeting inflammatory mediators and cytokines are on the horizon. Keywords: eosinophilic esophagitis, esophagitis, eosinophilia, dysphagia, allergy, corticosteroids, dietary treatment, dilation

A case of a canine oral eosinophilic granuloma in a 14-year-old female crossbred is described. The dog was presented with a history of ptyalism, halitosis, local pain, decreased appetite, and blood staining noted on food and water bowls. Clinical, hematologic, and biochemical examinations, abdominal ultrasonography, and 3-view chest radiographs were performed, and no metastases were found. Histopathologic examination of two 6 mm punch biopsies from the oral lesion revealed the presence of eosinophilic granulomatous lesions in the submucosa. After treatment with corticosteroids and wide spectrum antibiotics no significant changes in clinical signs and lesion size were observed. Electrochemotherapy (ECT), a novel tumor treatment routinely used for cutaneous and subcutaneous tumors in human patients in the European Union since 2006, was used to treat the eosinophilic granuloma. The procedure was performed under general anesthesia, followed by intravenous administration of bleomycin. Six weeks after treatment a complete response with disappearance of the mass and improvement of clinical signs were observed. ; Fil: Tellado, Matías Nicolás. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina ; Fil: Michinski, Sebastián Diego. Instituto Tecnológico de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina ; Fil: Olaiz, Nahuel Manuel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina ; Fil: Maglietti, Felipe Horacio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina ; Fil: Marshall, Guillermo Ricardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Abstract
Mammalian hosts combat bacterial infections through the production of defensive cationic antimicrobial peptides (CAPs). These immune factors are capable of directly killing bacterial invaders; however, many pathogens have evolved resistance evasion mechanisms such as cell surface modification, CAP sequestration, degradation, or efflux. We have discovered that several pathogenic and commensal proteobacteria, including the urgent human threat Neisseria gonorrhoeae, secrete a protein (lactoferrin-binding protein B, LbpB) that contains a low-complexity anionic domain capable of inhibiting the antimicrobial activity of host CAPs. This study focuses on a cattle pathogen, Moraxella bovis, that expresses the largest anionic domain of the LbpB homologs. We used an exhaustive biophysical approach employing circular dichroism, biolayer interferometry, cross-linking mass spectrometry, microscopy, size-exclusion chromatography with multi-angle light scattering coupled to small-angle X-ray scattering (SEC–MALS-SAXS), and NMR to understand the mechanisms of LbpB-mediated protection against CAPs. We found that the anionic domain of this LbpB displays an α-helical secondary structure but lacks a rigid tertiary fold. The addition of antimicrobial peptides derived from lactoferrin (i.e. lactoferricin) to the anionic domain of LbpB or full-length LbpB results in the formation of phase-separated droplets of LbpB together with the antimicrobial peptides. The droplets displayed a low rate of diffusion, suggesting that CAPs become trapped inside and are no longer able to kill bacteria. Our data suggest that pathogens, like M. bovis, leverage anionic intrinsically disordered domains for the broad recognition and neutralization of antimicrobials via the formation of biomolecular condensates.

A histidine-based gemini cationic lipid, which had already demonstrated its efficiency as a plasmid DNA (pDNA) nanocarrier, has been used in this work to transfect a small interfering RNA (siRNA) into cancer cells. In combination with the helper lipid monoolein glycerol (MOG), the cationic lipid was used as an antiGFP-siRNA nanovector in a multidisciplinary study. Initially, a biophysical characterization by zeta potential (ζ) and agarose gel electrophoresis experiments was performed to determine the lipid effective charge and confirm siRNA compaction. The lipoplexes formed were arranged in Lα lamellar lyotropic liquid crystal phases with a cluster-type morphology, as cryo-transmission electron microscopy (cryo-TEM) and small-angle X-ray scattering (SAXS) studies revealed. Additionally, in vitro experiments confirmed the high gene knockdown efficiency of the lipid-based nanovehicle as detected by flow cytometry (FC) and epifluorescence microscopy, even better than that of Lipofectamine2000*, the transfecting reagent commonly used as a positive control. Cytotoxicity assays indicated that the nanovector is non-toxic to cells. Finally, using nano-liquid chromatography tandem mass spectrometry (nanoLC-MS/MS), apolipoprotein A-I and A-II followed by serum albumin were identified as the proteins with higher affinity for the surface of the lipoplexes. This fact could be beyond the remarkable silencing activity of the histidine-based lipid nanocarrier herein presented ; This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (Grant RTI2018-095844-B-I00 and CTQ2017-88948-P), the University Complutense of Madrid (Spain) (project number UCMA05-33-010), and the Regional Government of Madrid (Grant P2018/NMT-4389). P.T. thanks Agencia Estatal de Investigación (AEI) through the Project MAT2016-80266-R and Xunta de Galicia (Grupo de Referencia Competitiva ED431C 2018/26; Agrupación Estratégica en Materiales-AEMAT ED431E 2018/08). ERDF funds are all greatly acknowledged. The proteomic ...

A histidine-based gemini cationic lipid, which had already demonstrated its efficiency as a plasmid DNA (pDNA) nanocarrier, has been used in this work to transfect a small interfering RNA (siRNA) into cancer cells. In combination with the helper lipid monoolein glycerol (MOG), the cationic lipid was used as an antiGFP-siRNA nanovector in a multidisciplinary study. Initially, a biophysical characterization by zeta potential (ζ) and agarose gel electrophoresis experiments was performed to determine the lipid effective charge and confirm siRNA compaction. The lipoplexes formed were arranged in Lα lamellar lyotropic liquid crystal phases with a cluster-type morphology, as cryo-transmission electron microscopy (cryo-TEM) and small-angle X-ray scattering (SAXS) studies revealed. Additionally, in vitro experiments confirmed the high gene knockdown efficiency of the lipid-based nanovehicle as detected by flow cytometry (FC) and epifluorescence microscopy, even better than that of Lipofectamine2000*, the transfecting reagent commonly used as a positive control. Cytotoxicity assays indicated that the nanovector is non-toxic to cells. Finally, using nano-liquid chromatography tandem mass spectrometry (nanoLC-MS/MS), apolipoprotein A-I and A-II followed by serum albumin were identified as the proteins with higher affinity for the surface of the lipoplexes. This fact could be beyond the remarkable silencing activity of the histidine-based lipid nanocarrier herein presented. ; This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (Grant RTI2018-095844-B-I00 and CTQ2017-88948-P), the University Complutense of Madrid (Spain) (project number UCMA05-33-010), and the Regional Government of Madrid (Grant P2018/NMT-4389). P.T. thanks Agencia Estatal de Investigación (AEI) through the Project MAT2016-80266-R and Xunta de Galicia (Grupo de Referencia Competitiva ED431C 2018/26; Agrupación Estratégica en Materiales-AEMAT ED431E 2018/08). ERDF funds are all greatly acknowledged. The proteomic analysis was performed in the Proteomics Unit of Complutense University of Madrid, a member of ProteoRed and is supported by grant PT17/0019, of the PE I+D+i 2013-2016, funded by ISCIII and ERDF. ; Peer reviewed

BACKGROUND: Eosinophilic esophagitis is a complex disease with an increasing prevalence. Multidisciplinary teams are often needed to manage this difficult-to-treat condition. OBJECTIVE: To observe the clinical and histologic outcomes of patients with eosinophilic esophagitis after management in a multidisciplinary clinic. METHODS: An observational, retrospective chart review was conducted to include all patients referred to the Walter Reed National Military Medical Center multidisciplinary eosinophilic esophagitis clinic between August 2012 and February 2021. Only patients who had at least one esophagogastroduodenoscopy before referral, one or more visits and endoscopy after multidisciplinary management, and documented clinical symptoms were included. Statistical analysis was performed by using McNemar and Wilcoxon tests. RESULTS: A total of 103 patients were included in the study, with a mean age at diagnosis of 17.9 years. Management in the multidisciplinary clinic was associated with a reduction in solid-food dysphagia by 70.9%, poor growth by 70.8%, and emesis or regurgitation by 87.5%. We observed that 48.5% and 62.1% had histologic remission (<15 eosinophils/hpf) on the initial and any post-multidisciplinary endoscopy, respectively. Only seven patients (5.8%) with two or more visits and endoscopies did not achieve histologic remission. More than two-thirds of the patients (68.9%) required combination therapy to achieve remission. CONCLUSION: Although an observational study, these findings may suggest that the management of patients with eosinophilic esophagitis in a multidisciplinary clinic may improve the likelihood of clinical and histologic remission. Targeted management with a multidisciplinary approach may reduce overall morbidity and slow disease progression; however, more research is needed.

Wolfgang Hohenforst-Schmidt,1 Andreas Riedel,1 Paul Zarogoulidis,2,3 Christian Franke,4 Andreas Gschwendtner,5 Haidong Huang,6 Nikolaos Machairiotis,2 Vasiliki Dramba,2 Konstantinos Zarogoulidis,2 Johnannes Brachmann11II Medical Clinic, Coburg Clinic, University of Würzburg, Coburg, Germany; 2Pulmonary Department, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 3Pulmonary Department–Interventional Unit, University of Duisburg-Essen, Essen, Germany; 4Pulmonary Department, Sonneberg, Germany; 5Institute for Pathology, Coburg Clinic, University of Würzburg, Coburg, Germany; 6Department of Respiratory Diseases, Changhai Hospital, Second Military Medical University, Shanghai, ChinaAbstract: Pulmonary eosinophilia comprises a heterogeneous group of diseases that are defined by eosinophilia in pulmonary infiltrates or in tissue. Drugs can cause almost all histopathologic patterns of interstitial pneumonias, such as cellular and fibrotic nonspecific interstitial pneumonia, pulmonary infiltrates and eosinophilia, organizing pneumonia, lymphocytic interstitial pneumonia, desquamative interstitial pneumonia, a pulmonary granulomatosis-like reaction, and a usual interstitial pneumonia-like pattern. We present a very rare case of chronic eosinophilic pneumonia due to radiographic contrast infusion diagnosed with video-assisted thoracoscopy. The patient after 1 year is still under corticosteroid treatment with the disease stabilized.Keywords: interstitial lung disease, radiographic contrast, orphan disease

The antibody crystallizable fragment (Fc) is recognized by effector proteins as part of the immune system. Pathogens produce proteins that bind Fc in order to subvert or evade the immune response. The structural characterization of the determinants of Fc–protein association is essential to improve our understanding of the immune system at the molecular level and to develop new therapeutic agents. Furthermore, Fc-binding peptides and proteins are frequently used to purify therapeutic antibodies. Although several structures of Fc–protein complexes are available, numerous others have not yet been determined. Protein–protein docking could be used to investigate Fc–protein complexes; however, improved approaches are necessary to efficiently model such cases. In this study, a docking-based structural bioinformatics approach is developed for predicting the structures of Fc–protein complexes. Based on the available set of X-ray structures of Fc–protein complexes, three regions of the Fc, loosely corresponding to three turns within the structure, were defined as containing the essential features for protein recognition and used as restraints to filter the initial docking search. Rescoring the filtered poses with an optimal scoring strategy provided a success rate of approximately 80% of the test cases examined within the top ranked 20 poses, compared to approximately 20% by the initial unrestrained docking. The developed docking protocol provides a significant improvement over the initial unrestrained docking and will be valuable for predicting the structures of currently undetermined Fc–protein complexes, as well as in the design of peptides and proteins that target Fc. ; This work was supported by grant number BIO2013‐48213‐R from Spanish Government. M.A. is a recipient of an NHMRC Early Career Fellowship (GNT1054245). We acknowledge the computational resources provided by the Australian Government through the Victorian Life Sciences Computational Initiative under the National Computational Merit Allocation Scheme (project dq3). The authors gratefully acknowledge the contribution toward this study fromthe VictorianOperational Infrastructure Support Program received by the Burnet Institute. ; Peer Reviewed ; Postprint (author's final draft)

The antibody crystallizable fragment (Fc) is recognized by effector proteins as part of the immune system. Pathogens produce proteins that bind Fc in order to subvert or evade the immune response. The structural characterization of the determinants of Fc–protein association is essential to improve our understanding of the immune system at the molecular level and to develop new therapeutic agents. Furthermore, Fc-binding peptides and proteins are frequently used to purify therapeutic antibodies. Although several structures of Fc–protein complexes are available, numerous others have not yet been determined. Protein–protein docking could be used to investigate Fc–protein complexes; however, improved approaches are necessary to efficiently model such cases. In this study, a docking-based structural bioinformatics approach is developed for predicting the structures of Fc–protein complexes. Based on the available set of X-ray structures of Fc–protein complexes, three regions of the Fc, loosely corresponding to three turns within the structure, were defined as containing the essential features for protein recognition and used as restraints to filter the initial docking search. Rescoring the filtered poses with an optimal scoring strategy provided a success rate of approximately 80% of the test cases examined within the top ranked 20 poses, compared to approximately 20% by the initial unrestrained docking. The developed docking protocol provides a significant improvement over the initial unrestrained docking and will be valuable for predicting the structures of currently undetermined Fc–protein complexes, as well as in the design of peptides and proteins that target Fc. ; This work was supported by grant number BIO2013‐48213‐R from Spanish Government. M.A. is a recipient of an NHMRC Early Career Fellowship (GNT1054245). We acknowledge the computational resources provided by the Australian Government through the Victorian Life Sciences Computational Initiative under the National Computational Merit Allocation Scheme (project dq3). The authors gratefully acknowledge the contribution toward this study fromthe VictorianOperational Infrastructure Support Program received by the Burnet Institute. ; Peer Reviewed ; Postprint (author's final draft)