3,999 research outputs found

    Long-term prevention of renal insufficiency, excess matrix gene expression, and glomerular mesangial matrix expansion by treatment with monoclonal antitransforming growth factor-ß antibody in \u3ci\u3edb/db\u3c/i\u3e diabetic mice

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    Emerging evidence suggests that transforming growth factor-(TGF-β) is an important mediator of diabetic nephropathy. We showed previously that short-term treatment with a neutralizing monoclonal anti-TGF-antibody (αT) in streptozotocin-diabetic mice prevents early changes of renal hypertrophy and increased matrix mRNA. To establish that overactivity of the renal TGF-system mediates the functional and structural changes of the more advanced stages of nephropathy, we tested whether chronic administration of αT prevents renal insufficiency and glomerulosclerosis in the db/db mouse, model of type 2 diabetes that develops overt nephropathy. Diabetic db/db mice and nondiabetic db/m littermates were treated intraperitoneally with α or control IgG, 300 µg three times per week for 8 wk. Treatment with αT, but not with IgG, significantly decreased the plasma TGF-β1 concentration without decreasing the plasma glucose concentration. The IgG-treated db/db mice developed albuminuria, renal insufficiency, and glomerular mesangial matrix expansion associated with increased renal mRNAs encoding α 1(IV) collagen and fibronectin. On the other hand, treatment with α completely prevented the increase in plasma creatinine concentration, the decrease in urinary creatinine clearance, and the expansion of mesangial matrix in db/db mice. The increase in renal matrix mRNAs was substantially attenuated, but the excretion of urinary albumin factored for creatinine clearance was not significantly affected by α treatment. We conclude that chronic inhibition of the biologic actions of TGF-with neutralizing monoclonal antibody in db/db mice prevents the glomerulosclerosis and renal insufficiency resulting from type diabetes

    Clickable albumin nanoparticles for pretargeted drug delivery toward PD-L1 overexpressing tumors in combination immunotherapy

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    We present a simple methodology to design a pretargeted drug delivery system, based on clickable anti-programmed death ligand 1 (anti-PD-L1) antibodies (Abs) and clickable bovine serum albumin (BSA) nanoparticles (NPs). Pretargeted drug delivery is based on the decoupling of a targeting moiety and a drug-delivering vector which can then react in vivo after separate injections. This may be key to achieve active targeting of drug-delivering NPs toward cancerous tissue. In pretargeted approaches, drug-delivering NPs were observed to accumulate in a higher amount in the targeted tissue due to shielding-related enhanced blood circulation and size-related enhanced tissue penetration. In this work, BSA NPs were produced using the solvent precipitation methodology that renders colloidally stable NPs, which were subsequently functionalized with a clickable moiety based on chlorosydnone (Cl-Syd). Those reactive groups are able to specifically react with dibenzocyclooctyne (DBCO) groups in a click-type fashion, reaching second-order reaction rate constants as high as 1.9 M-1·s-1, which makes this reaction highly suitable for in vivo applications. The presence of reactive Cl-Syd was demonstrated by reacting the functionalized NPs with a DBCO-modified sulfo-cyanine-5 dye. With this reaction, it was possible to infer the number of reactive moieties per NPs. Finally, and with the aim of demonstrating the suitability of this system to be used in pretargeted strategies, functionalized fluorescent NPs were used to label H358 cells with a clickable anti-PD-L1 Ab, applying the reaction between Cl-Syd and DBCO as corresponding clickable groups. The results of these experiments demonstrate the bio-orthogonality of the system to perform the reaction in vitro, in a period as short as 15 mi

    Effects of high glucose and TGF-β1 on the expression of collagen IV and vascular endothelial growth factor in mouse podocytes

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    Effects of high glucose and TGF-β1 on the expression of collagen IV and vascular endothelial growth factor in mouse podocytes.BackgroundThe podocyte takes center stage in the pathogenesis of glomerular basement membrane (GBM) thickening and proteinuria in diabetic glomerulopathy. In part, GBM thickening may occur when the podocyte synthesizes increased amounts of collagen IV. Proteinuria may develop if the podocyte secretes excessive amounts of vascular endothelial growth factor (VEGF), which may increase the glomerular permeability to macromolecules. The augmented production of collagen IV and VEGF may be caused by metabolic mediators of diabetes such as hyperglycemia and transforming growth factor-β (TGF-β).MethodsThe effects of high glucose and exogenous TGF-β1 were examined on a mouse podocyte cell line that retains its differentiated phenotype. The gene expression and protein production of certain alpha chains of collagen IV, the major isoforms of VEGF, and components of the TGF-β system were assayed. An inhibitor of TGF-β signaling was used to determine whether some of the high glucose effects might be mediated by the TGF-β system.ResultsCompared with normal glucose (5.5 mmol/L), high glucose (HG, 25 mmol/L) for 14 days stimulated [3H]-proline incorporation, a measure of collagen production, by 1.8-fold, and exogenous TGF-β1 (2 ng/mL) for 24 hours stimulated proline incorporation by 2.4-fold. Northern analysis showed that exposure to HG for 14 days increased the mRNA level of α1(IV) collagen by 51% and α5(IV) by 90%, whereas treatment with TGF-β1 (2 ng/mL) for 24 hours decreased the mRNA level of α1(IV) by 36% and α5(IV) by 40%. Consistent with these effects on mRNA expression, Western blotting showed that HG increased α1(IV) protein by 44% and α5(IV) by 28%, while TGF-β1 decreased α1(IV) protein by 29% and α5(IV) by 7%. In contrast to their opposing actions on α1 and α5(IV), both HG and exogenous TGF-β1 increased α3(IV) collagen and VEGF, with TGF-β1 having the greater effect. An inhibitor of the TGF-β type I receptor (ALK5) was able to prevent the stimulation of α3(IV) and VEGF proteins by HG. Unlike in other renal cell types, HG did not increase TGF-β1 mRNA or protein in the podocyte, but HG did induce the expression of the ligand-binding TGF-β type II receptor (TβRII). Because HG had up-regulated TβRII after two weeks, the addition of physiological-dose TGF-β1 (0.010 ng/mL) for 24 hours stimulated the production of α3(IV) and VEGF proteins to a greater extent in high than in normal glucose. Up-regulation of TβRII in the podocyte was corroborated by immunohistochemistry of the kidney cortex in the db/db mouse, a model of type 2 diabetes.ConclusionsHigh glucose and exogenous TGF-β1 exert disparate effects on the expression of α1 and α5(IV) collagen. However, high glucose and TGF-β1 coordinately induce the production of α3(IV) collagen and VEGF in the podocyte. The HG-induced increases in α3(IV) collagen and VEGF proteins are mediated by the TGF-β system. By increasing the expression of TβRII, high glucose may augment the response of the podocyte to ambient levels of TGF-β1

    Adjustable near-infrared fluorescence lifetime emission of biocompatible rare-earth-doped nanoparticles for in vivo multiplexing

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    Rare-earth-doped inorganic nanocrystals are an important class of nanoparticles for bioimaging applications due to the facility of providing them with tailored emissions in the visible and near-infrared regions of the electromagnetic spectrum. Recently it has become of interest to engineer the dopant composition of these materials in order to enable multiplexed lifetime imaging for autofluorescence-free in vivo bioimaging. Herein we report a simple approach to obtain different fluorescence lifetimes for the Yb3+emission (2F5/2 → 2F7/2) in Nd3+, Yb3+, Tm3+ co-doped NaGdF4 nanoparticles by only changing their crystal size while keeping their hydrodynamic diameter constant. This allowed straightforward transformation of infrared images in the time domain into lifetime maps. The particles were then deployed as in vivo contrast agents for near-infrared imaging in a mouse demonstrating their multiplexing capabilityThis work was financed by the Spanish Ministerio de Ciencia e Inovación under projects PID2019-106211RB-I00 and PID2020-118878RB-I00, by the Instituto de Salud Carlos III (PI19/00565), by the Comunidad Autónoma de Madrid (CAM) S2017/ BMD3867 RENIM-CM grant and co-financed by the European structural and investment fund. Additional funding was provided by the European Union Horizon 2020 FETOpen project NanoTBTech (801305), the CAM young investigator project SI3/PJI/2021-00211 the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal project IMP21_A4 (2021/0427), and also by COST action CA17140. R. M. acknowledges the support of the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 797945 (LANTERNS). J.Y. acknowledges the support from the China Scholarship Council (CSC File No.201704910867

    2018 consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary

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    Cancer of unknown primary (CUP) is defned as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They difer from other primary tumours in their biological features and how they spread, which means that they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, CUP can account for 2–9% of all cancer patients, mostly 60–75 years old. This article reviews the main clinical, pathological, and molecular studies conducted to analyse and determine the origin of CUP.The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.The authors are grateful for the editorial assistance of Dr. Fernando Sánchez-Barbero of HealthCo (Madrid, Spain) in the production of this manuscript. SEOM and SEAP are grateful for the fnancial support for this project in the form of unrestricted grants from Ferrer Diagnostic, OncoDNA and Foundation Medicine/Roche

    2018 consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary

    Get PDF
    Cancer of unknown primary (CUP) is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means that they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, CUP can account for 2-9% of all cancer patients, mostly 60-75years old. This article reviews the main clinical, pathological, and molecular studies conducted to analyse and determine the origin of CUP. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed

    Mural Endocarditis: The GAMES Registry Series and Review of the Literature

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    Introduction: Mural infective endocarditis (MIE) is a rare type of endovascular infection. We present a comprehensive series of patients with mural endocarditis. Methods: Patients with infectious endocarditis (IE) from 35 Spanish hospitals were prospectively included in the GAMES registry between 2008 and 2017. MIEs were compared to non-MIEs. We also performed a literature search for cases of MIE published between 1979 and 2019 and compared them to the GAMEs series. Results: Twenty-seven MIEs out of 3676 IEs were included. When compared to valvular IE (VIE) or device-associated IE (DIE), patients with MIE were younger (median age 59 years, p < 0.01). Transplantation (18.5% versus 1.6% VIE and 2% DIE, p < 0.01), hemodialysis (18.5% versus 4.3% VIE and 4.4% DIE, p = 0.006), catheter source (59.3% versus 9.7% VIE and 8.8% DIE, p < 0.01) and Candida etiology (22.2% versus 2% DIE and 1.2% VIE, p < 0.01) were more common in MIE, whereas the Charlson Index was lower (4 versus 5 in non-MIE, p = 0.006). Mortality was similar. MIE from the literature shared many characteristics with MIE from GAMES, although patients were younger (45 years vs. 56 years, p < 0.001), the Charlson Index was lower (1.3 vs. 4.3, p = 0.0001), catheter source was less common (13.9% vs. 59.3%) and there were more IVDUs (25% vs. 3.7%). S. aureus was the most frequent microorganism (50%, p = 0.035). Systemic complications were more common but mortality was similar. Conclusion: MIE is a rare entity. It is often a complication of catheter use, particularly in immunocompromised and hemodialysis patients. Fungal etiology is common. Mortality is similar to other IEs

    Dedifferentiation of Immortalized Human Podocytes in Response to Transforming Growth Factor-β: A Model for Diabetic Podocytopathy

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    OBJECTIVE: Diabetic nephropathy is associated with dedifferentiation of podocytes, losing the specialized features required for efficient glomerular function and acquiring a number of profibrotic, proinflammatory, and proliferative features. These result from tight junction and cytoskeletal rearrangement, augmented proliferation, and apoptosis. RESEARCH DESIGN AND METHODS: Experiments were performed in conditionally immortalized human podocytes developed by transfection with the temperature-sensitive SV40-T gene. Cells were then cultured in the presence of transforming growth factor (TGF)-β1 or angiotensin II in the presence or absence of a selective inhibitor of the TGF-β type I receptor kinase, SB-431542. Gene and protein expression were then examined by real-time RT-PCR and immunofluorescence, and correlated with changes observed in vivo in experimental diabetes. RESULTS: Treatment of cells with TGF-β1 resulted in dynamic changes in their morphology, starting with retraction and shortening of foot processes and finishing with the formation of broad and complex tight junctions between adjacent podocytes. This dedifferentiation was also associated with dose- and time-dependent reduction in the expression of glomerular epithelial markers (nephrin, p-cadherin, zonnula occludens-1) and increased expression of mesenchymal markers (α-smooth muscle actin, vimentin, nestin), matrix components (fibronectin, collagen I, and collagen IV α3), cellular proliferation, and apoptosis. The induction of diabetes in mice was also associated with similar changes in morphology, protein expression, and proliferation in glomerular podocytes. CONCLUSIONS: In response to TGF-β and other TGF-dependent stimuli, mature podocytes undergo dedifferentiation that leads to effacement of foot processes, morphologic flattening, and increased formation of intercellular tight junctions. This simplification of their phenotype to a more embryonic form is also associated with reentry of mature podocytes into the cell cycle, which results in enhanced proliferation and apoptosis. These "pathoadaptive" changes are seen early in the diabetic glomerulus and ultimately contribute to albuminuria, glomerulosclerosis, and podocytopenia

    f(R) theories

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    Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom
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