A model of epileptogenesis in rhinal cortex-hippocampus organotypic slice cultures

Copyright © 2021 JoVE Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported LicenseOrganotypic slice cultures have been widely used to model brain disorders and are considered excellent platforms for evaluating a drug's neuroprotective and therapeutic potential. Organotypic slices are prepared from explanted tissue and represent a complex multicellular ex vivo environment. They preserve the three-dimensional cytoarchitecture and local environment of brain cells, maintain the neuronal connectivity and the neuron-glia reciprocal interaction. Hippocampal organotypic slices are considered suitable to explore the basic mechanisms of epileptogenesis, but clinical research and animal models of epilepsy have suggested that the rhinal cortex, composed of perirhinal and entorhinal cortices, play a relevant role in seizure generation. Here, we describe the preparation of rhinal cortex-hippocampus organotypic slices. Recordings of spontaneous activity from the CA3 area under perfusion with complete growth medium, at physiological temperature and in the absence of pharmacological manipulations, showed that these slices depict evolving epileptic-like events throughout time in culture. Increased cell death, through propidium iodide uptake assay, and gliosis, assessed with fluorescence-coupled immunohistochemistry, was also observed. The experimental approach presented highlights the value of rhinal cortex-hippocampus organotypic slice cultures as a platform to study the dynamics and progression of epileptogenesis and to screen potential therapeutic targets for this brain pathology.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement Nº 952455, Fundação para a Ciência e Tecnologia (FCT) through Project PTDC/MEDFAR/30933/2017, and Faculdade de Medicina da Universidade de Lisboainfo:eu-repo/semantics/publishedVersio

Consortin, a trans-Golgi network cargo receptor for the plasma membrane targeting and recycling of connexins

Targeting of numerous transmembrane proteins to the cell surface is thought to depend on their recognition by cargo receptors that interact with the adaptor machinery for anterograde traffic at the distal end of the Golgi complex. We report here on consortin, a novel integral membrane protein that is predicted to be intrinsically disordered, i.e. that contains large segments whose native state is unstructured. We identified consortin as a binding partner of connexins, the building blocks of gap junctions. Consortin is located at the trans-Golgi network (TGN), in tubulovesicular transport organelles, and at the plasma membrane. It directly interacts with the TGN clathrin adaptors GGA1 and GGA2, and disruption of this interaction by expression of a consortin mutant lacking the acidic cluster-dileucine (DXXLL) GGA interaction motif causes an intracellular accumulation of several connexins. RNA interference-mediated silencing of consortin expression in HeLa cells blocks the cell surface targeting of these connexins, which accumulate intracellularly, whereas partial depletion and redistribution of the consortin pool slows down the intracellular degradation of gap junction plaques. Altogether, our results show that, by studying connexin trafficking, we have identified the first TGN cargo receptor for the targeting of transmembrane proteins to the plasma membrane. The identification of consortin provides in addition a potential target for therapies aimed at diseases in which connexin traffic is altered, including cardiac ischemia, peripheral neuropathies, cataracts and hearing impairment. Sequence accession numbers. GenBank: Human CNST cDNA, NM_152609; mouse Cnst cDNA, NM_14610

Analytical and clinical validation of a blood progranulin ELISA in frontotemporal dementias

OBJECTIVES: Heterozygous mutations in the granulin (GRN) gene may result in haploinsufficiency of progranulin (PGRN), which might lead to frontotemporal dementia (FTD). In this study, we aimed to perform analytical and clinical validation of a commercial progranulin kit for clinical use. METHODS: Analytical validation parameters including assay precision, selectivity, measurement range, dilution linearity, interferences and sample stability were tested according to previously described procedures. For clinical validation, PGRN levels were measured in plasma from 32 cognitively healthy individuals, 52 confirmed GRN mutation carriers, 25 C9orf72 mutation carriers and 216 patients with different neurodegenerative diseases of which 70 were confirmed as non-mutation carriers. RESULTS: Among the analytical validation parameters, assay precision and repeatability were very stable (coefficients of variation <7 %). Spike recovery was 96 %, the measurement range was 6.25-400 μg/L and dilution linearity ranged from 1:50-1:200. Hemolysis did not interfere with progranulin levels, and these were resistant to freeze/thaw cycles and storage at different temperatures. For the clinical validation, the assay was capable of distinguishing GRN mutation carriers from controls and non-GRN mutation carriers with very good sensitivity and specificity at a cut-off of 57 μg/L (97 %, 100 %, respectively). CONCLUSIONS: In this study, we demonstrate robust analytical and diagnostic performance of this commercial progranulin kit for implementation in clinical laboratory practice. This easy-to-use test allows identification of potential GRN mutation carriers, which may guide further evaluation of the patient. This assay might also be used to evaluate the effect of novel PGRN-targeting drugs and therapies

Neurofilament light oligomers in neurodegenerative diseases: quantification by homogeneous immunoassay in cerebrospinal fluid

BACKGROUND: Neurofilament light (NfL) is a widely used biomarker for neurodegeneration. NfL is prone to oligomerisation, but available assays do not reveal the exact molecular nature of the protein variant measured. The objective of this study was to develop a homogeneous ELISA capable of quantifying oligomeric NfL (oNfL) in cerebrospinal fluid (CSF). METHODS: A homogeneous ELISA, based on the same capture and detection antibody (NfL21), was developed and used to quantify oNfL in samples from patients with behavioural variant frontotemporal dementia (bvFTD, n=28), non-fluent variant primary progressive aphasia (nfvPPA, n=23), semantic variant PPA (svPPA, n=10), Alzheimer's disease (AD, n=20) and healthy controls (n=20). The nature of NfL in CSF, and the recombinant protein calibrator, was also characterised by size exclusion chromatography (SEC). RESULTS: CSF concentration of oNfL was significantly higher in nfvPPA (p<0.0001) and svPPA patients (p<0.05) compared with controls. CSF oNfL concentration was also significantly higher in nfvPPA compared with bvFTD (p<0.001) and AD (p<0.01) patients. SEC data showed a peak fraction compatible with a full-length dimer (~135 kDa) in the in-house calibrator. For CSF, the peak was found in a fraction of lower molecular weight (~53 kDa), suggesting dimerisation of NfL fragments. CONCLUSIONS: The homogeneous ELISA and SEC data suggest that most of the NfL in both the calibrator and human CSF is present as a dimer. In CSF, the dimer appears to be truncated. Further studies are needed to determine its precise molecular composition

Effect of Maraviroc intensification on HIV-1-specific T cell immunity in recently HIV-1-infected individuals

BACKGROUND: The effect of maraviroc on the maintenance and the function of HIV-1-specific T cell responses remains unknown. METHODS: Subjects recently infected with HIV-1 were randomized to receive anti-retroviral treatment with or without maraviroc intensification for 48 weeks, and were monitored up to week 60. PBMC and in vitro-expanded T cells were tested for responses to the entire HIV proteome by ELISpot analyses. Intracellular cytokine staining assays were conducted to monitor the (poly)-functionality of HIV-1-specific T cells. Analyses were performed at baseline and week 24 after treatment start, and at week 60 (3 months after maraviroc discontinuation). RESULTS: Maraviroc intensification was associated with a slower decay of virus-specific T cell responses over time compared to the non-intensified regimen in both direct ex-vivo as well as in in-vitro expanded cells. The effector function profiles of virus-specific CD8⁺ T cells were indistinguishable between the two arms and did not change over time between the groups. CONCLUSIONS: Maraviroc did not negatively impact any of the measured parameters, but was rather associated with a prolonged maintenance of HIV-1-specific T cell responses. Maraviroc, in addition to its original effect as viral entry inhibitor, may provide an additional benefit on the maintenance of virus-specific T cells which may be especially important for future viral eradication strategies

EN-DALBACEN 2.0 Cohort: real-life study of dalbavancin as sequential/consolidation therapy in patients with infective endocarditis due to Gram-positive cocci

Objectives: Infective endocarditis (IE) has high mortality and morbidity and requires long hospital stays to deliver the antibiotic treatment recommended in clinical practice guidelines. We aimed to analyse the health outcomes of the use of dalbavancin (DBV) in the consolidation treatment of IEs caused by Gram-positive cocci and to perform a pharmacoeconomic study. Materials and methods: This observational, retrospective, Spanish multicentre study in patients with IE who received DBV as part of antibiotic treatment in consolidation phase were followed for at least 12 months. The study was approved by the Provincial Committee of the coordinating centre. Results: The study included 124 subjects, 70.2% male, with a mean age of 67.4 years and median Charlson index of 4 (interquartile range: 2.5-6). Criteria for definite IE were met by 91.1%. Coagulase-negative staphylococci (38.8%), Staphylococcus aureus (22.6%), Enterococcus faecalis (19.4%), and Streptococcus Spp. (9.7%) were isolated more frequently, all susceptible to vancomycin. Before DVB administration, 91.2% had undergone surgery; 60.5% had received a second regimen for 24.5 d (16.6-56); and 20.2% had received a third regimen for 14.5 d (12-19.5). DBV was administered to facilitate discharge in 95.2% of cases. At 12 months, the effectiveness was of 95.9%, and there was 0.8% loss to follow-up, 0.8% IE-related death, and 3.2% relapse. Adverse events were recorded in 3.2%. The hospital stay was reduced by 14 d, and there was a mean savings of 5548.57 €/patient vs. conventional treatments. Conclusion: DBV is highly effective, safe, and cost-effective as consolidation therapy in patients with IE by Gram-positive cocci, with few adverse events

2016 Expert consensus document on prevention, diagnosis and treatment of short-term peripheral venous catheter-related infections in adult.

Aquest document també està publicat a: 'Cirugía Cardiovascular' http://dx.doi.org/10.1016/j.circv.2016.06.001The use of endovascular catheters is a routine practice in secondary and tertiary care level hospitals. Short peripheral catheters have been found to be associated with the risk of nosocomial bacteremia resulting in morbidity and mortality. Staphyloccus aureus is mostly associated with peripheral catheter insertion. This Consensus Document has been elaborated by a panel of experts of the Spanish Society of Cardiovascular Infections in cooperation with experts from the Spanish Society of Internal Medicine, Spanish Society of Chemotherapy and Spanish Society of Thoracic-Cardiovascular Surgery and aims at define and establish the norm for management of short duration peripheral vascular catheters. The document addresses the indications for insertion, catheter maintenance and registry, diagnosis and treatment of infection, indications for removal and stresses on continuous education as a driver for quality. Implementation of this norm will allow uniformity in usage thus minimizing the risk of infection and its complications

Multivalvular Endocarditis: A Rare Condition with Poor Prognosis.

Background. Infective endocarditis (IE) is a severe condition. Our aim was to describe the profile and prognosis of patients with multivalvular infective endocarditis (MIE) and compare them to single-valve IE (SIE). Methods. We used a retrospective analysis of the Spanish IE Registry (2008−2020). Results. From 4064 definite cases of valvular IE, 577 (14.2%) had MIE. In patients with MIE, the most common locations were mitral (552, 95.7%) and aortic (550, 95.3%), with mitral-aortic involvement present in 507 patients (87.9%). The most common etiologies were S. viridans (192, 33.3%) and S. aureus (113, 19.6%). MIE involved only native valves in 450 patients (78.0%). Compared with patients with SIE, patients with MIE had a similar age (69 vs. 67 years, respectively, p = 0.27) and similar baseline characteristics, but were more frequently men (67.1% vs. 72.9%, p = 0.005) and had a higher incidence of intracardiac complications (36.2% vs. 50.4%, p < 0.001), heart failure (42.7% vs. 52.9%, p < 0.001), surgical indication (67.7 vs. 85.1%, p < 0.001), surgery (46.3% vs. 56.3%), and in-hospital mortality (26.9% vs. 34.3%, p < 0.001). MIE was an independent predictor of in-hospital mortality (odds ratio (OR) 1.3, 95% confidence interval (CI) 1.1−1.7, p = 0.004) but did not have an independent association with 1-year mortality (OR 1.1, 95% CI 0.9−1.4, p = 0.43). Conclusions. About one-seventh of the valvular IE patients had MIE, mainly due to mitral-aortic involvement. MIE is associated with a poor in-hospital prognosis. An early diagnosis and treatment of IE might avoid its spread to a second valve