Antibody density on bacteria regulates C1q recruitment by monoclonal IgG but not IgM.

Antibodies that trigger the complement system play a pivotal role in the immune defense against pathogenic bacteria and offer potential therapeutic avenues for combating antibiotic-resistant bacterial infections, a rising global concern. To gain a deeper understanding of the key parameters regulating complement activation by monoclonal antibodies, we developed a novel bioassay for quantifying classical complement activation at the monoclonal antibody level, and employed this assay to characterize rare complement-activating antibacterial antibodies on the single-antibody level in postimmunization murine antibody repertoires. We characterized monoclonal antibodies from various antibody isotypes against specific pathogenic bacteria (Bordetella pertussis and Neisseria meningitidis) to broaden the scope of our findings.

A Guide to the Quantitation of Protein Secretion Dynamics at the Single-Cell Level.

Protein secretion is a key cellular functionality, particularly in immunology, where cells can display large heterogeneity in this crucial activity in addition to binary secretion behavior. However, few methods enable quantitative secretion rate measurements at the single-cell level, and these methods are mostly based on microfluidics systems. Here, we describe such a microfluidic single-cell method for precisely measuring protein secretion rates in detail, building on the published droplet-based microfluidic platform DropMap.

Transcriptomic Analysis of Extracellular Vesicles in the Search for Novel Plasma and Thrombus Biomarkers of Ischemic Stroke Etiologies.

Accurate etiologic diagnosis provides an appropriate secondary prevention and better prognosis in ischemic stroke (IS) patients; still, 45% of IS are cryptogenic, urging us to enhance diagnostic precision. We have studied the transcriptomic content of plasma extracellular vesicles (EVs) ( = 21) to identify potential biomarkers of IS etiologies. The proteins encoded by the selected genes were measured in the sera of IS patients ( = 114) and in hypertensive patients with ( = 78) and without atrial fibrillation (AF) ( = 20).

Role of factor XIII in ischemic stroke: a key molecule promoting thrombus stabilization and resistance to lysis.

Background: Active coagulation factor XIII (FXIII) catalyzing crosslinking of fibrin and other hemostatic factors plays a key role in clot stability and lysis.

Objectives: To evaluate the effect of FXIII inhibition in a mouse model of ischemic stroke (IS) and the role of activated FXIII (FXIIIa) in clot formation and lysis in patients with IS.

Methods: A ferric chloride IS murine model was performed before and after administration of a FXIIIa inhibitor (FXIIIinh).

Analysis of the prognostic value of emergency blood tests in ischaemic stroke.

Objectives: This study aims to evaluate the prognostic value of emergency blood test results in patients with acute ischaemic stroke.

Methods: We evaluated 592 prospectively patients with neuroimaging-confirmed ischaemic stroke admitted to our stroke unit between 2015 and 2018. We gathered emergency blood test results and calculated the neutrophil-to-lymphocyte ratio and the neutrophil-to-platelet ratio (neutrophils × 1.

Association of calprotectin with other inflammatory parameters in the prediction of mortality for ischemic stroke.

Background: Inflammatory response plays an important role in many processes related to acute ischemic stroke (AIS). Calprotectin (S100A8/S100A9), released by monocytes and neutrophils, is a key protein in the regulation of inflammation and thrombosis. The purpose of this study is to evaluate the association of circulating calprotectin with other inflammatory biomarkers and AIS prognosis, as well as the calprotectin content in stroke thrombi.

Inflammatory Response of Ischemic Tolerance in Circulating Plasma: Preconditioning-Induced by Transient Ischemic Attack (TIA) Phenomena in Acute Ischemia Patients (AIS).

Ischemic tolerance (IT) refers to a state where cells are resistant to the damaging effects caused by periods of ischemia. In a clinical scenario, the IT phenomenon would be activated by a recent transient ischemic attack (TIA) before an ischemic stroke (IS). The characterization of inflammatory protein expression patterns will contribute to improved understanding of IT.

Dynamic single-cell phenotyping of immune cells using the microfluidic platform DropMap.

Characterization of immune responses is currently hampered by the lack of systems enabling quantitative and dynamic phenotypic characterization of individual cells and, in particular, analysis of secreted proteins such as cytokines and antibodies. We recently developed a simple and robust microfluidic platform, DropMap, to measure simultaneously the kinetics of secretion and other cellular characteristics, including endocytosis activity, viability and expression of cell-surface markers, from tens of thousands of single immune cells. Single cells are compartmentalized in 50-pL droplets and analyzed using fluorescence microscopy combined with an immunoassay based on fluorescence relocation to paramagnetic nanoparticles aligned to form beadlines in a magnetic field.

Circular RNA expression profile in blood according to ischemic stroke etiology.

Background: The discovery of novel biomarkers of stroke etiology would be most helpful in management of acute ischemic stroke patients. Recently, circular RNAs (circRNAs) have been proposed as candidate biomarkers of neurological conditions due to its high stability. circRNAs function as sponges, sequestering miRNAs and are involved in most relevant biological functions.

Mass Spectrometry-Based Proteomic Profiling of Thrombotic Material Obtained by Endovascular Thrombectomy in Patients with Ischemic Stroke.

Thrombotic material retrieved from acute ischemic stroke (AIS) patients represents a valuable source of biological information. In this study, we have developed a clinical proteomics workflow to characterize the protein cargo of thrombi derived from AIS patients. To analyze the thrombus proteome in a large-scale format, we developed a workflow that combines the isolation of thrombus by endovascular thrombectomy and peptide chromatographic fractionation coupled to mass-spectrometry.

GRECOS Project (Genotyping Recurrence Risk of Stroke): The Use of Genetics to Predict the Vascular Recurrence After Stroke.

Background And Purpose: Vascular recurrence occurs in 11% of patients during the first year after ischemic stroke (IS) or transient ischemic attack. Clinical scores do not predict the whole vascular recurrence risk; therefore, we aimed to find genetic variants associated with recurrence that might improve the clinical predictive models in IS.

Methods: We analyzed 256 polymorphisms from 115 candidate genes in 3 patient cohorts comprising 4482 IS or transient ischemic attack patients.

[Reperfusion in acute ischaemic stroke: present and future].

Cerebral ischaemia is a dynamic process triggered when an intracranial artery is acutely occluded, normally due to an embolism from the heart or from arteriolosclerotic lesions of more proximal arteries. Urgent rerouting of these arteries and early reperfusion of the cerebral tissue, neuroprotector therapies that intervene in the ischaemic cascade and prevention of recurrence are the therapeutic aims in the acute phase of ischaemic stroke. Thrombolytic treatment pursues the lysis of the dot occluding the intracranial artery.

[Stroke in the XXI century. Emergency care].

Cerebrovascular diseases have reached epidemic proportions worldwide. They are the major cause of mortality in developed countries, accounting for over one-quarter of worldwide documented deaths, and the leading cause of severe disability in adults. Given that Spain will become one of the countries most affected by population ageing, an increase in the incidence of these diseases is expected in coming years.

[Involuntary movements in brainstem ischemic lesions].

Introduction: The appearance of movement disorders in vascular disease of the brainstem has hardly been described in the literature. Its frequency is probably underestimated due to their briefness and that they are often misinterpreted as epileptic seizures. Their pathophysiological mechanism is uncertain.

[Rhombencephalitis caused by Listeria: clinical-radiological correlation].

Rhombencephalitis due to Listeria is a serious and infrequent infection of the brainstem. It principally affects subjects who were previously healthy. It shows itself clinically in two phases: the first with unspecific symptoms, which could last one week, and the second with the appearance of focal neurologic signs at the level of the brainstem.

[Internal carotid stenosis and giant cell arteritis].

We report on the case of a 69-year-old man admitted with a transient ischemic attack preceded by a two months history of severe headache. Giant cell arteritis was diagnosed by means of temporal artery biopsy. Angiography showed an intra- and extracranial stenosis of the left internal carotid artery.

Acute carotid obliteration: a new vascular manifestation in POEMS syndrome.

The case of a 65-year-old woman with polyneuropathy, organomegaly, skin changes and monoclonal gammopathy of IgG-lambda type is described. This patient developed an acute carotid obliteration during oral anticoagulation and despite absence of vascular risk factors. Macroangiopathy has been described as a rare systemic manifestation of POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal spike and skin changes), affecting the coronary and lower limbs arteries.