Explore the vast range of titles available.

Purpose The purpose of this study was to determine the clinical utility of three bony tubercles: fibular obscure tubercle, talar obscure tubercle and tuberculum ligamenti calcaneofibularis, to serve as anatomical landmarks for defining the precise location of the origins and insertions of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL). Methods Twelve lower extremity cadaveric specimens were procured. The detectability of the tubercles was tested using palpation and fluoroscopy with subsequent confirmation after dissection. If the tubercles were present, then distances from the identified tubercles to the footprint centres and the intersection of the ATFL and CFL were measured to allow precise localization of the ATFL and CFL origin and intersection sites. Further, if the tubercles were not detectable, then an attempt to provide an alternative means of localizing ATFL and CFL origin and insertion sites was made by measuring distances between alternative landmarks and other important structures. All the measurements were performed by two researchers, and the results were averaged. Results The fibular obscure tubercle existed and was detectable in all specimens. It was located 1.3 mm proximal to the articular tip of the fibula, 2.7 mm to the intersection of the ATFL and CFL, 3.7 mm distal to the ATFL and 4.9 mm proximal to the CFL origins. The talar obscure tubercle existed 58 % of specimens and was detectable in 57 %. The talar obscure tubercle was located 1.4 mm to the ATFL. The ATFL insertion point was located 60 % of the distance from the inferolateral corner to the anterolateral corner of the of talar body along the anterior border of the talar lateral articular facet. The tuberculum ligamenti calcaneofibularis existed in 33 % of specimens and was detectable in 8 %. The CFL inserted 17 mm on a perpendicular projected line distal from the subtalar joint. Conclusions The fibular obscure tubercle was clinically relevant and reliable bony landmark of the ATFL and CFL origin location. However, the talar obscure tubercle was less reliable and the tuberculum ligamenti calcaneofibularis was rarely available and as such alternative landmarks for the ATFL and CFL insertion location should be utilized. The present study describes the utility of clinically relevant bony landmarks that may assist in identifying the origins and insertions of the ATFL and CFL to facilitate minimally invasive ankle stabilization surgery.

Inducible nitric oxide synthase (iNOS), which produce large amounts of nitric oxide (NO), is induced in macrophages and microglia in response to inflammatory mediators such as LPS and cytokines. Although iNOS is mainly expressed by microglia that become activated in different pathological and experimental situations, it was recently reported that undifferentiated amoeboid microglia can also express iNOS during normal development. The aim of this study was to investigate the pattern of iNOS expression in microglial cells during normal development and after their activation with LPS by using the quail retina as model. iNOS expression was analyzed by iNOS immunolabeling, western-blot, and RT-PCR. NO production was determined by using DAR-4M AM, a reliable fluorescent indicator of subcellular NO production by iNOS. Embryonic, postnatal, and adult in situ quail retinas were used to analyze the pattern of iNOS expression in microglial cells during normal development. iNOS expression and NO production in LPS-treated microglial cells were investigated by an in vitro approach based on organotypic cultures of E8 retinas, in which microglial cell behavior is similar to that of the in situ retina, as previously demonstrated in our laboratory. We show here that amoeboid microglia in the quail retina express iNOS during normal development. This expression is stronger in microglial cells migrating tangentially in the vitreal part of the retina and is downregulated, albeit maintained, when microglia differentiate and become ramified. LPS treatment of retina explants also induces changes in the morphology of amoeboid microglia compatible with their activation, increasing their lysosomal compartment and upregulating iNOS expression with a concomitant production of NO. Taken together, our findings demonstrate that immature microglial cells express iNOS during normal development, suggesting a certain degree of activation. Furthermore, LPS treatment induces overactivation of amoeboid microglia, resulting in a significant iNOS upregulation.

Microglia are the tissue-resident macrophages of the central nervous parenchyma. In mammals, microglia are thought to originate from yolk sac precursors and posteriorly maintained through the entire life of the organism. However, contribution of microglial cells from other sources should also be considered. In addition to “true” or “bona-fide” microglia, which are of embryonic origin, the so-called “microglia-like cells” are hematopoietic cells of bone marrow origin that can engraft the mature brain mainly under pathological conditions. These cells implement great parts of the microglial immune phenotype, but they do not completely adopt the “true microglia” features. Because of their pronounced similarity, true microglia and microglia-like cells are usually considered together as one population. In this review, we discuss the origin and development of these two distinct cell types and their differences. We will also review the factors determining the appearance and presence of microglia-like cells, which can vary among species. This knowledge might contribute to the development of therapeutic strategies aiming at microglial cells for the treatment of diseases in which they are involved, as for example neurodegenerative disorders like Alzheimer´s and Parkinson´s diseases.

The molecular processes that determine the outcome of influenza virus infection in humans are multifactorial and involve a complex interplay between host, viral and bacterial factors 1 . However, it is generally accepted that a strong innate immune dysregulation known as ‘cytokine storm’ contributes to the pathology of infections with the 1918 H1N1 pandemic or the highly pathogenic avian influenza viruses of the H5N1 subtype 2 – 4 . The RNA sensor retinoic acid-inducible gene I (RIG-I) plays an important role in sensing viral infection and initiating a signalling cascade that leads to interferon expression 5 . Here, we show that short aberrant RNAs (mini viral RNAs (mvRNAs)), produced by the viral RNA polymerase during the replication of the viral RNA genome, bind to and activate RIG-I and lead to the expression of interferon-β. We find that erroneous polymerase activity, dysregulation of viral RNA replication or the presence of avian-specific amino acids underlie mvRNA generation and cytokine expression in mammalian cells. By deep sequencing RNA samples from the lungs of ferrets infected with influenza viruses, we show that mvRNAs are generated during infection in vivo. We propose that mvRNAs act as the main agonists of RIG-I during influenza virus infection. Aberrant mini viral RNAs, which are produced by erroneous RNA polymerase activity during the replication of the viral RNA genome, act as the main agonists of RIG-I during influenza virus infection.

The role of microglia during neurodegeneration remains controversial. We investigated whether microglial cells have a neurotoxic or neuroprotective function in the retina. Retinal explants from 10-day-old mice were treated in vitro with minocycline to inhibit microglial activation, with LPS to increase microglial activation, or with liposomes loaded with clodronate (Lip-Clo) to deplete microglial cells. Flow cytometry was used to assess the viability of retinal cells in the explants and the TUNEL method to show the distribution of dead cells. The immunophenotypic and morphological features of microglia and their distribution were analyzed with flow cytometry and immunocytochemistry. Treatment of retinal explants with minocycline reduced microglial activation and simultaneously significantly decreased cell viability and increased the presence of TUNEL-labeled cell profiles. This treatment also prevented the migration of microglial cells towards the outer nuclear layer, where cell death was most abundant. The LPS treatment increased microglial activation but had no effect on cell viability or microglial distribution. Finally, partial microglial removal with Lip-Clo diminished the cell viability in the retinal explants, showing a similar effect to that of minocycline. Hence, cell viability is diminished in retinal explants cultured in vitro when microglial cells are removed or their activation is inhibited, indicating a neurotrophic role for microglia in this system.

Subtalar instability remains a topic of debate, and its precise cause is still unknown. The mechanism of injury and clinical symptoms of ankle and subtalar instabilities largely overlap, resulting in many cases of isolated or combined subtalar instability that are often misdiagnosed. Neglecting the subtalar instability may lead to failure of conservative or surgical treatment and result in chronic ankle instability. Understanding the accurate anatomy and biomechanics of the subtalar joint, their interplay, and the contributions of the different subtalar soft tissue structures is fundamental to correctly diagnose and manage subtalar instability. An accurate diagnosis is crucial to correctly identify those patients with instability who may require conservative or surgical treatment. Many different nonsurgical and surgical approaches have been proposed to manage combined or isolated subtalar instability, and the clinician should be aware of available treatment options to make an informed decision. In this current concepts narrative review, we provide a comprehensive overview of the current knowledge on the anatomy, biomechanics, clinical and imaging diagnosis, nonsurgical and surgical treatment options, and outcomes after subtalar instability treatment.

During development microglia colonize the central nervous system (CNS) and play an important role in programmed cell death, not only because of their ability to remove dead cells by phagocytosis, but also because they can promote the death of neuronal and glial cells. To study this process, we used as experimental systems the developing in situ quail embryo retina and organotypic cultures of quail embryo retina explants (QEREs). In both systems, immature microglia show an upregulation of certain inflammatory markers, e.g., inducible NO synthase (iNOS), and nitric oxide (NO) under basal conditions, which can be further enhanced with LPS-treatment. Hence, we investigated in the present study the role of microglia in promoting ganglion cell death during retinal development in QEREs. Results showed that LPS-stimulation of microglia in QEREs increases (i) the percentage of retinal cells with externalized phosphatidylserine, (ii) the frequency of phagocytic contacts between microglial and caspase-3-positive ganglion cells, (iii) cell death in the ganglion cell layer, and (iv) microglial production of reactive oxygen/nitrogen species, such as NO. Furthermore, iNOS inhibition by L-NMMA decreases cell death of ganglion cells and increases the number of ganglion cells in LPS-treated QEREs. These data demonstrate that LPS-stimulated microglia induce ganglion cell death in cultured QEREs by a NO-dependent mechanism. The fact that phagocytic contacts between microglial and caspase-3-positive ganglion cells increase suggests that this cell death might be mediated by microglial engulfment, although a phagocytosis-independent mechanism cannot be excluded.

Poly(ADP-ribose)polymerases (PARPs) are a family of NAD+ consuming enzymes that play a crucial role in many cellular processes, most clearly in maintaining genome integrity. Here, we present an extensive analysis of the alteration of mitochondrial morphology and the relationship to PARPs activity after oxidative stress using an in vitro model of human hepatic cells. The following outcomes were observed: reactive oxygen species (ROS) induced by oxidative treatment quickly stimulated PARPs activation, promoted changes in mitochondrial morphology associated with early mitochondrial fragmentation and energy dysfunction and finally triggered apoptotic cell death. Pharmacological treatment with specific PARP-1 (the major NAD+ consuming poly(ADP-ribose)polymerases) and PARP-1/PARP-2 inhibitors after the oxidant insult recovered normal mitochondrial morphology and, hence, increased the viability of human hepatic cells. As the PARP-1 and PARP-1/PARP-2 inhibitors achieved similar outcomes, we conclude that most of the PARPs effects were due to PARP-1 activation. NAD+ supplementation had similar effects to those of the PARPs inhibitors. Therefore, PARPs activation and the subsequent NAD+ depletion are crucial events in decreased cell survival (and increased apoptosis) in hepatic cells subjected to oxidative stress. These results suggest that the alterations in mitochondrial morphology and function seem to be related to NAD+ depletion, and show for the first time that PARPs inhibition abrogates mitochondrial fragmentation. In conclusion, the inhibition of PARPs may be a valuable therapeutic approach for treating liver diseases, by reducing the cell death associated with oxidative stress.

Antioxidant defenses in biological systems ensure redox homeostasis, regulating baseline levels of reactive oxygen and nitrogen species (ROS and RNS). Oxidative stress (OS), characterized by a lack of antioxidant defenses or an elevation in ROS and RNS, may cause a modification of biomolecules, ROS being primarily absorbed by proteins. As a result of both genome and environment interactions, proteomics provides complete information about a cell’s proteome, which changes continuously. Besides measuring protein expression levels, proteomics can also be used to identify protein modifications, localizations, the effects of added agents, and the interactions between proteins. Several oxidative processes are frequently used to modify proteins post-translationally, including carbonylation, oxidation of amino acid side chains, glycation, or lipid peroxidation, which produces highly reactive alkenals. Reactive alkenals, such as 4-hydroxy-2-nonenal, are added to cysteine (Cys), lysine (Lys), or histidine (His) residues by a Michael addition, and tyrosine (Tyr) residues are nitrated and Cys residues are nitrosylated by a Michael addition. Oxidative and nitrosative stress have been implicated in many neurodegenerative diseases as a result of oxidative damage to the brain, which may be especially vulnerable due to the large consumption of dioxygen. Therefore, the current methods applied for the detection, identification, and quantification in redox proteomics are of great interest. This review describes the main protein modifications classified as chemical reactions. Finally, we discuss the importance of redox proteomics to health and describe the analytical methods used in redox proteomics.

Background: Patients with B-lymphocyte malignancies (BCMs) receiving B-lymphocyte-targeted therapies have increased risk of severe COVID-19 outcomes and impaired antibody response to SARS-CoV-2 mRNA vaccination in comparison to non-hematologic oncologic patients or general population. Consequently, it is vital to explore vaccine-induced T-lymphocyte responses in patients referred for the understanding of immune protection against SARS-CoV2 infections. The objective of the present study was to analyze the recall immune responses carried out by T lymphocytes after two COVID-19 mRNA vaccine doses. Methods: We enrolled 40 patients with BCMs and 10 healthy controls (HCs) after 4 weeks from the second mRNA vaccine dose. Spike (S)-specific T-lymphocyte responses were assessed in peripheral blood mononuclear lymphocytes (PBMCs) by intracellular IFN-γ staining combined with flow cytometry. Furthermore, the humoral response was assessed with the measurement of anti-spike antibodies. Results: From March to July 2021, 40 patients (median age 68) received mRNA vaccines. The overall antibody response for BCMs was 52.5% versus 100% for the healthy controls (p = 0.008). The antibody response was different across BCMs: 18.75% for non-Hodgkin lymphoma, 54.5% for chronic lymphocytic leukemia, and 92.3% for multiple myeloma. Responses varied by malignancy type and treatment, with anti-CD20 therapies showing the lowest response (6.7%). T-lymphocyte analysis revealed reduced numbers and altered differentiation stages in patients compared to the controls. However, the vaccine-induced T response was generally robust, with variations in specific T subpopulations. Conclusions: mRNA vaccines induced significant humoral and cellular immune responses in B-cell lymphoid malignancy patients, although responses varied by treatment type and malignancy. Further research is needed to optimize vaccination strategies in this population.