478 research outputs found
Profiling the serum protein corona of fibrillar human islet amyloid polypeptide
Amyloids may be regarded as native nanomaterials that form in the presence of complex protein mixtures. By drawing an analogy with the physicochemical properties of nanoparticles in biological fluids, we hypothesized that amyloids should form a protein corona in vivo that would imbue the underlying amyloid with a modified biological identity. To explore this hypothesis we characterized the protein corona of human islet amyloid polypeptide (IAPP) fibrils in FBS using two complementary methodologies developed herein; quartz crystal microbalance and ‘centrifugal capture’, coupled with nano-liquid chromatography tandem mass spectroscopy. Clear evidence for a significant protein corona was obtained. No trends were identified for amyloid corona proteins based on their physicochemical properties, while strong binding with IAPP fibrils occurred for linear proteins or multi-domain proteins with structural plasticity. Proteomic analysis identified amyloid-enriched proteins that are known to play significant roles in mediating cellular machinery and processing, potentially leading to pathological outcomes and therapeutic targets
Inclusion Ideals Associated to Uniformly Increasing Hypergraphs
In this paper,we introduce the monomial ideals I(H) associated to a special
class of non uniform hypergraphs H(X; E; d) namely uniformly increasing
hypergraphs. These ideals are named as inclusion ideals. In this paper, we
discuss some algebraic properties of these inclusion ideals. In particular, we
give an upper bound of the Castlenouvo-Mumford regularity of the special dual
ideal I^[*](H) of the inclusion ideal.Comment: 6 pages, 1 figur
Metformin alleviates lung-endothelial hyperpermeability by regulating cofilin-1/PP2AC pathway
Background: Microvascular endothelial hyperpermeability is an earliest pathological hallmark in Acute Lung Injury (ALI), which progressively leads to Acute Respiratory Distress Syndrome (ARDS). Recently, vascular protective and anti-inflammatory effect of metformin, irrespective of glycemic control, has garnered significant interest. However, the underlying molecular mechanism(s) of metformin’s barrier protective benefits in lung-endothelial cells (ECs) has not been clearly elucidated. Many vascular permeability-increasing agents weakened adherens junctions (AJ) integrity by inducing the reorganization of the actin cytoskeleton and stress fibers formation. Here, we hypothesized that metformin abrogated endothelial hyperpermeability and strengthen AJ integrity via inhibiting stress fibers formation through cofilin-1-PP2AC pathway.Methods: We pretreated human lung microvascular ECs (human-lung-ECs) with metformin and then challenged with thrombin. To investigate the vascular protective effects of metformin, we studied changes in ECs barrier function using electric cell-substrate impedance sensing, levels of actin stress fibers formation and inflammatory cytokines IL-1β and IL-6 expression. To explore the downstream mechanism, we studied the Ser3-phosphorylation-cofilin-1 levels in scramble and PP2AC-siRNA depleted ECs in response to thrombin with and without metformin pretreatment.Results: In-vitro analyses showed that metformin pretreatment attenuated thrombin-induced hyperpermeability, stress fibers formation, and the levels of inflammatory cytokines IL-6 and IL-β in human-lung-ECs. We found that metformin mitigated Ser3-phosphorylation mediated inhibition of cofilin-1 in response to thrombin. Furthermore, genetic deletion of PP2AC subunit significantly inhibited metformin efficacy to mitigate thrombin-induced Ser3-phosphorylation cofilin-1, AJ disruption and stress fibers formation. We further demonstrated that metformin increases PP2AC activity by upregulating PP2AC-Leu309 methylation in human-lung-ECs. We also found that the ectopic expression of PP2AC dampened thrombin-induced Ser3-phosphorylation-mediated inhibition of cofilin-1, stress fibers formation and endothelial hyperpermeability.Conclusion: Together, these data reveal the unprecedented endothelial cofilin-1/PP2AC signaling axis downstream of metformin in protecting against lung vascular endothelial injury and inflammation. Therefore, pharmacologically enhancing endothelial PP2AC activity may lead to the development of novel therapeutic approaches for prevention of deleterious effects of ALI on vascular ECs
Bariatric Surgical Practice During the Initial Phase of COVID-19 Outbreak
There is no data on patients with severe obesity who developed coronavirus disease 2019 (COVID-19) after bariatric surgery. Four gastric bypass operations, performed in a 2-week period between Feb 24 and March 4, 2020, in Tehran, Iran, were complicated with COVID-19. The mean age and body mass index were 46 ± 12 years and 49 ± 3 kg/m2. Patients developed their symptoms (fever, cough, dyspnea, and fatigue) 1, 2, 4, and 14 days after surgery. One patient had unnoticed anosmia 2 days before surgery. Three patients were readmitted in hospital. All 4 patients were treated with hydroxychloroquine. In two patients who required admission in intensive care unit, other off-label therapies including antiretroviral and immunosuppressive agents were also administered. All patients survived. In conclusion, COVID-19 can complicate the postoperative course of patients after bariatric surgery. Correct diagnosis and management in the postoperative setting would be challenging. Timing of infection after surgery in our series would raise the possibility of hospital transmission of COVID-19: from asymptomatic patients at the time of bariatric surgery to the healthcare workers versus acquiring the COVID-19 infection by non-infected patients in the perioperative period. © 2020, Springer Science+Business Media, LLC, part of Springer Nature
Protocol for the development of a global core outcome set for the surgical treatment of differentiated thyroid cancer:a literature review and international Delphi survey
Introduction:There is a lack of consensus on the optimal surgical strategy for differentiated thyroid cancer (DTC), partly due to inconsistent reporting of outcomes. This limits the ability to compare study results, hindering the ability to draw conclusions regarding novel treatment strategies. The development of a core outcome set (COS) reduces heterogeneity in the selection and reporting of clinical trial outcomes. Currently, there is no COS for the surgical treatment of DTC. We aim to reach a global consensus among patients and physicians on the COS for the surgical treatment for patients with DTC of all ages. Methods and analysis: The DTC-COS development will consist of three phases: first, an extensive literature review will be performed to identify reported outcomes in studies regarding surgical treatment for DTC in patients of all ages. Second, a 2-step or 3-step Delphi procedure will be performed to identify a final set of core outcomes out of the selected outcomes from the literature review. For this Delphi survey, both healthcare professionals and patients will be invited. Third, an (online) expert meeting with participants from every stakeholder group is organised to ratify the final core outcome set. The final COS will be reported in accordance with the COS-Standards for Reporting statement. Ethics and dissemination: The medical research ethics committee of the Amsterdam UMC confirmed that the Dutch Medical Research Involving Human Subjects Act (WMO) does not apply to this study and that full approval by the committee is not required. The study is registered in the COMET initiative database (registration number 2597). Results will be presented in peer-reviewed academic journals and at (international) conferences.</p
The Definition of Recurrence of Differentiated Thyroid Cancer:A Systematic Review of the Literature
Background: Recurrence is a key outcome to evaluate the treatment effect of differentiated thyroid carcinoma (DTC). However, no consistent definition of recurrence is available in current literature or international guidelines. Therefore, the primary aim of this systematic review was to delineate the definitions of recurrence of DTC, categorized by total thyroidectomy with radioactive iodine ablation (RAI), total thyroidectomy without RAI and lobectomy, to assess if there is a generally accepted definition among these categories.Methods: This study adhered to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. In December 2023, a systematic literature search in MEDLINE and EMBASE was performed for studies reporting on the recurrence of DTC, from January 2018 to December 2023. Studies that did not provide a definition were excluded. Primary outcome was the definition of recurrence of DTC. Secondary outcome was whether studies differentiated between recurrence and persistent disease. Two independent investigators screened the titles and abstracts, followed by full-text assessment and data extraction. The study protocol was registered in PROSPERO, CRD42021291753.Results: In total, 1450 studies were identified. Seventy studies met the inclusion criteria, including 69 retrospective studies and 1 randomised controlled trial (RCT). Median number of patients in the included studies was 438 (range 25-2297). In total, 17 studies (24.3%) reported on lobectomy, 4 studies (5.7%) on total thyroidectomy without RAI, and 49 studies (70.0%) with RAI. All studies defined recurrence using one or a combination of four diagnostic modalities cytology/pathology, imaging studies, thyroglobulin (-antibodies), and a predetermined minimum tumor-free time span. The most common definition of recurrence following lobectomy was cytology/pathology-proven recurrence (47.1% of this subgroup), following total thyroidectomy with RAI was cytology/pathology-proven recurrence and/or anomalies detected on imaging studies (22.4% of this subgroup). No consistent definition was found following total thyroidectomy without RAI. Nine studies (12.9%) differentiated between recurrence and persistent disease.Conclusion: Our main finding is that there is no universally accepted definition for recurrence of DTC in the current studies across any of the treatment categories. The findings of this study will provide the basis for a future, international Delphi-based proposal to establish a universally accepted definition of recurrence of DTC. A uniform definition could facilitate global discussion and enhance the assessment of treatment outcomes regarding recurrence of DTC.</p
Basic fibroblast growth factor and vascular endothelial growth factor serum levels in breast cancer patients and healthy women: useful as diagnostic tools?
INTRODUCTION: The aim of the present study was to analyze the relationship between the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in breast cancer cells and the corresponding serum levels in individual patients. The study also evaluated the potential of serum levels of the two growth factors as diagnostic markers in a case–control study. METHODS: VEGF expression and bFGF expression were determined in 62 and 63 tumor samples, respectively. Serum VEGF and bFGF levels were determined in 54 and 65 healthy women and in 69 and 73 breast cancer patients, respectively, using a quantitative sandwich enzyme immunoassay technique. RESULTS: A direct correlation was observed between VEGF expression and bFGF expression in individual tumors (P = 0.001) and between serum levels (P = 0.038) in individual patients, but not between tumor cell expression and the corresponding serum level for either growth factor. Median values of serum levels in healthy women and breast cancer patients were not different for VEGF (P = 0.055), but were significantly different for bFGF (P < 0.001). The receiver operating characteristic curve identified a serum bFGF concentration of 1.0 pg/ml, with 84.9% sensitivity and 63.1% specificity, as the best cut-off value to discriminate between healthy women and breast cancer patients. An age-based subgroup analysis showed that serum values of patients older than 70 years of age mainly contributed to the high accuracy. CONCLUSIONS: Our data repropose bFGF as a noninvasive diagnostic tool for breast cancer
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