Separating Actin-Dependent Chemokine Receptor Nanoclustering from Dimerization Indicates a Role for Clustering in CXCR4 Signaling and Function.

A current challenge in cell motility studies is to understand the molecular and physical mechanisms that govern chemokine receptor nanoscale organization at the cell membrane, and their influence on cell response. Using single-particle tracking and super-resolution microscopy, we found that the chemokine receptor CXCR4 forms basal nanoclusters in resting T cells, whose extent, dynamics, and signaling strength are modulated by the orchestrated action of the actin cytoskeleton, the co-receptor CD4, and its ligand CXCL12. We identified three CXCR4 structural residues that are crucial for nanoclustering and generated an oligomerization-defective mutant that dimerized but did not form nanoclusters in response to CXCL12, which severely impaired signaling. Overall, our data provide new insights to the field of chemokine biology by showing that receptor dimerization in the absence of nanoclustering is unable to fully support CXCL12-mediated responses, including signaling and cell function in vivo.

A progesterone derivative linked to a stable phospholipid activates breast cancer cell response without leaving the cell membrane.

In hormone-responsive breast cancer cells, progesterone (P4) has been shown to act via its nuclear receptor (nPR), a ligand-activated transcription factor. A small fraction of progesterone receptor is palmitoylated and anchored to the cell membrane (mbPR) forming a complex with estrogen receptor alpha (ERα). Upon hormone exposure, either directly or via interaction with ERα, mbPR activates the SRC/RAS/ERK kinase pathway leading to phosphorylation of nPR by ERK. Kinase activation is essential for P4 gene regulation, as the ERK and MSK1 kinases are recruited by the nPR to its genomic binding sites and trigger chromatin remodeling. An interesting open question is whether activation of mbPR can result in gene regulation in the absence of ligand binding to intracellular progesterone receptor (iPR). This matter has been investigated in the past using P4 attached to serum albumin, but the attachment is leaky and albumin can be endocytosed and degraded, liberating P4. Here, we propose a more stringent approach to address this issue by ensuring attachment of P4 to the cell membrane via covalent binding to a stable phospholipid. This strategy identifies the actions of P4 independent from hormone binding to iPR. We found that a membrane-attached progestin can activate mbPR, the ERK signaling pathway leading to iPR phosphorylation, initial gene regulation and entry into the cell cycle, in the absence of detectable intracellular progestin.

Stochastic particle unbinding modulates growth dynamics and size of transcription factor condensates in living cells.

Liquid-liquid phase separation (LLPS) is emerging as a key physical principle for biological organization inside living cells, forming condensates that play important regulatory roles. Inside living nuclei, transcription factor (TF) condensates regulate transcriptional initiation and amplify the transcriptional output of expressed genes. However, the biophysical parameters controlling TF condensation are still poorly understood. Here we applied a battery of single-molecule imaging, theory, and simulations to investigate the physical properties of TF condensates of the progesterone receptor (PR) in living cells. Analysis of individual PR trajectories at different ligand concentrations showed marked signatures of a ligand-tunable LLPS process. Using a machine learning architecture, we found that receptor diffusion within condensates follows fractional Brownian motion resulting from viscoelastic interactions with chromatin. Interestingly, condensate growth dynamics at shorter times is dominated by Brownian motion coalescence (BMC), followed by a growth plateau at longer timescales that result in nanoscale condensate sizes. To rationalize these observations, we extended on the BMC model by including the stochastic unbinding of particles within condensates. Our model reproduced the BMC behavior together with finite condensate sizes at the steady state, fully recapitulating our experimental data. Overall, our results are consistent with condensate growth dynamics being regulated by the escaping probability of PR molecules from condensates. The interplay between condensation assembly and molecular escaping maintains an optimum physical condensate size. Such phenomena must have implications for the biophysical regulation of other nuclear condensates and could also operate in multiple biological scenarios.

Prediction of acute neurovascular syndromes with prehospital clinical features witnessed by bystanders.

BACKGROUND: The prompt recognition of an acute neurovascular syndrome by the patient or a bystander witnessing the event can directly influence outcome. We aimed to study the predictive value of the medical history and clinical features recognized by the patients' bystanders to preclassify acute stroke syndromes in prehospital settings. METHODS: We analyzed 369 patients: 209 (56.6%) with acute ischemic stroke (AIS), 107 (29.0%) with intracerebral hemorrhage (ICH), and 53 (14.4%) with subarachnoid hemorrhage (SAH). All patients had neuroimaging as diagnostic gold standard. We constructed clinical prediction rules (CPRs) with features recognized by the bystanders witnessing the stroke onset to classify the acute neurovascular syndromes before final arrival to the emergency room (ER). RESULTS: In all, 83.2% cases were referred from other centers, and only 16.8% (17.2% in AIS, 15% in ICH, and 18.9% in SAH) had direct ER arrival. The time to first assessment in ≤ 3 h occurred in 72.4% (73.7%, 73.8%, and 64.2%, respectively), and final ER arrival in ≤ 3 h occurred in 26.8% (32.1%, 15.9%, and 28.3%, respectively). Clinical features referred by witnesses had low positive predictive values (PPVs) for stroke type prediction. Language or speech disorder + focal motor deficit showed 63.3% PPV, and 77.0% negative predictive value (NPV) for predicting AIS. Focal motor deficit + history of hypertension had 35.9% PPV and 78.8% NPV for ICH. Headache alone had 27.9% PPV and 95.3% NPV for SAH. In multivariate analyses, seizures, focal motor deficit, and hypertension increased the probability of a time to first assessment in ≤ 3 h, while obesity was inversely associated. Final ER arrival was determined by age and a direct ER arrival without previous referrals. CONCLUSION: CPRs constructed with the witnesses' narrative had only adequate NPVs in the prehospital classification of acute neurovascular syndromes, before neuroimaging confirmation.

Clinical and radiological characteristics in patients with SARS-CoV-2-associated pneumonia. A descriptive study in a secondary care center.

INTRODUCTION: Real-time reverse-transcription polymerase chain reaction (RT-PCR) is the gold standard for establishing the diagnosis of coronavirus disease 2019 (COVID-19). Chest computed tomography (CCT), as a diagnostic complement, classifies tomographic findings according to the COVID-19 Reporting and Data System (CO-RADS). OBJECTIVE: To determine CCT sensitivity and specificity for COVID-19 diagnosis. METHODS: We reviewed RT-PCR results, as well as their respective CCTs. All CCTs were classified according to CO-RADS. CCT sensitivity and specificity were evaluated using the RT-PCR result that was closest to that of CCT as reference. RESULTS: We included 412 patients, out of whom 277 were males (46-70 years) and 130 were females (45-71 years); with 181 negative and 231 positive tests, a sensitivity of 92.15% and specificity of 79.32% were obtained. Mortality increased after six hospitalization days, in males and in CO-RADS 4, 5 and 6 in comparison with CO-RADS 1, 2 and 3. CONCLUSIONS: Early diagnosis plays a decisive role in the prognosis of SARS-CoV-2-associated pneumonia. Although RT-PCR is current gold standard, false negatives are common; for this reason, CCT helps to confirm suspected cases, even at early stages. This imaging technique is an accessible and fundamental study for classification, diagnosis and prognosis.

INTRODUCCIÓN: La reacción en cadena de la polimerasa con transcripción inversa en tiempo real (RT-PCR) es el estándar de oro para establecer el diagnóstico de enfermedad por coronavirus 2019 (COVID-19). La tomografía computarizada de tórax (TCT), como complemento diagnóstico, clasifica los hallazgos tomográficos de acuerdo con el sistema CO-RADS (COVID-19 Reporting and Data System). OBJETIVO: Determinar la sensibilidad y especificidad de la TCT para el diagnóstico de COVID-19. MÉTODOS: Consultamos los resultados de RT-PCR, así como sus respectivas TCT. Todas las TCT se clasificaron de según CO-RADS. Se evaluó sensibilidad y especificidad de la TCT utilizando el resultado de RT-PCR más cercano de TCT como referencia. RESULTADOS: Incluimos 412 pacientes, incluyendo 277 hombres (46-70 años) y 130 mujeres (45-71 años), con 181 pruebas negativas y 231 positivas; obteniendo sensibilidad del 92.15% y especificidad del 79.32%. La mortalidad aumentó después de seis días de hospitalización, en el sexo masculino y en CO-RADS 4, 5 y 6 en comparación con CO-RADS 1, 2 y 3. CONCLUSIONES: El diagnóstico temprano es decisivo en el pronóstico de la neumonía SARS CoV 2. Aunque la RT-PCR es el estándar de oro actual, los falsos negativos son frecuentes, por lo que la TCT ayuda a confirmar los casos sospechosos, incluso en etapas tempranas. Este estudio de imagen es un estudio accesible y fundamental para la clasificación, diagnóstico y pronóstico.

Reliability of Bystander Recognition of Clinical Features in Pre-Hospital Classification of Acute Cerebrovascular Syndromes: Preliminary Findings.

BACKGROUND: The recognition of stroke symptoms by patients or bystanders directly affects the outcomes of patients with acute cerebrovascular disease. OBJECTIVE: The objective of the study was to assess the predictive value of the medical his- tory and clinical features recognized by the patients' bystanders to classify neurovascular syndromes in pre-hospital settings. METHODS: We included 150 stroke patients of two Mexican referral centers: 50 with acute ischemic stroke (AIS), 50 with intracerebral hemorrhage (ICH), and 50 with subarachnoid hemorrhage (SAH). The performance of clinical prediction rules (CPR) to identify the stroke types was evaluated with features recognized by the patients' bystanders before hospital arrival. The impact of CPRs on early arrival and in-hospital mortality was also analyzed. RESULTS: Overall, 72% of the patients had previous medical evaluations in other centers before final referral to our hospitals, and therefore, only 45% had a final onset- to-door time <6 h, even when the first medical assessment had occurred in ≤1 h in 75% of cases. Clinical features noticed by the patients' bystanders had low positive predictive values (PPV) for any stroke type. The CPR "language or speech disor- der + focal motor deficit" had 93% sensitivity and a negative predictive value (NPV) of 84% to distinguish AIS. In SAH, head- ache alone showed a sensitivity of 84% and NPV of 97%. No CPR had an adequate performance on ICH. CPRs were not as- sociated with final onset-to-door time. Altered consciousness, age ≥65 years, indirect arrival with stops before final referral, and atrial fibrillation increased in-hospital mortality. CONCLUSION: Clinical features referred by the witness of a neurovascular emergency have limited PPV, but adequate NPV in ruling-out AIS and SAH among stroke types. The use of CPRs had no impact on onset-to-door time or in-hospital mortality when the final arrival to a third-level center occurs with previous medical refer- rals.

Inhomogeneous membrane receptor diffusion explained by a fractional heteroscedastic time series model.

Single particle tracking experiments have recently uncovered that the motion of cell membrane components can undergo changes of diffusivity as a result of the heterogeneous environment, producing subdiffusion and nonergodic behavior. In this paper, we show that an autoregressive fractionally integrated moving average (ARFIMA) with noise given by generalized autoregressive conditional heteroscedasticity (GARCH) can describe inhomogeneous diffusion in the cell membrane, where the ARFIMA process models anomalous diffusion and the GARCH process explains a fluctuating diffusion parameter.

The actin cytoskeleton modulates the activation of iNKT cells by segregating CD1d nanoclusters on antigen-presenting cells.

Invariant natural killer T (iNKT) cells recognize endogenous and exogenous lipid antigens presented in the context of CD1d molecules. The ability of iNKT cells to recognize endogenous antigens represents a distinct immune recognition strategy, which underscores the constitutive memory phenotype of iNKT cells and their activation during inflammatory conditions. However, the mechanisms regulating such "tonic" activation of iNKT cells remain unclear. Here, we show that the spatiotemporal distribution of CD1d molecules on the surface of antigen-presenting cells (APCs) modulates activation of iNKT cells. By using superresolution microscopy, we show that CD1d molecules form nanoclusters at the cell surface of APCs, and their size and density are constrained by the actin cytoskeleton. Dual-color single-particle tracking revealed that diffusing CD1d nanoclusters are actively arrested by the actin cytoskeleton, preventing their further coalescence. Formation of larger nanoclusters occurs in the absence of interactions between CD1d cytosolic tail and the actin cytoskeleton and correlates with enhanced iNKT cell activation. Importantly and consistently with iNKT cell activation during inflammatory conditions, exposure of APCs to the Toll-like receptor 7/8 agonist R848 increases nanocluster density and iNKT cell activation. Overall, these results define a previously unidentified mechanism that modulates iNKT cell autoreactivity based on the tight control by the APC cytoskeleton of the sizes and densities of endogenous antigen-loaded CD1d nanoclusters.

Enfermedad carotídea aterosclerosa y enfermedad de sustancia blanca en sujetos sin historia de infarto cerebral o isquemia cerebral transitoria.

INTRODUCTION: Atherosclerotic carotid artery disease (CAD) is a major risk factor for cerebrovascular disease. OBJECTIVE: To analyze the association of major vascular risk factors with atherosclerotic CAD and white matter disease (WMD) in patients without a history of ischemic stroke. METHOD: Risk factors were assessed with carotid examination using Doppler duplex ultrasound. Cases with a history cerebral infarction or transient ischemic attack were not included. Subjects had brain magnetic resonance imaging scans available and those with large-artery ischemic lesions were excluded. Multivariate models were constructed for the prediction of atherosclerotic CAD, significant carotid stenosis, atheroma burden and WMD. RESULTS: One-hundred and forty-five subjects were assessed (60.7% were females, mean age was 73 years). Atherosclerotic CAD was documented in 54.5%, carotid stenosis ≥ 50% in 9.0%, > 6 atheroma plaques in 7.6%, and periventricular or subcortical WMD in 28.3% (20.6% had atherosclerotic CAD and WMD concurrently). Risk factors independently associated with atherosclerotic CAD were age and hypertension; hypertension was associated with ≥ 50% carotid stenosis; age was associated with > 6 atheroma plaques; and age, diabetes and hypertension were associated with WMD. Obesity was not associated with any of the analyzed independent variables. CONCLUSIONS: In asymptomatic subjects without a history of ischemic stroke, age and hypertension were the most important risk factors for macrovascular disease. Diabetes mellitus was associated with microvascular disease. Obesity alone was not a major determinant of CAD or WMD.

INTRODUCCIÓN: La enfermedad carotídea aterosclerosa (ECA) es un factor de riesgo importante para enfermedad vascular cerebral. OBJETIVO: Analizar la asociación entre factores de riesgo vascular mayores con ECA y leucopatía cerebral en pacientes sin historia de ictus isquémico. MÉTODO: Se evaluaron factores de riesgo en sujetos con exploración de carótidas mediante ultrasonografía Doppler dúplex. No se incluyeron casos con historia de infarto cerebral o ataque isquémico transitorio. Los sujetos contaron con resonancia magnética cerebral y se excluyeron aquellos con lesiones isquémicas de grandes vasos. Se construyeron modelos multivariable para la predicción de ECA, estenosis carotídea significativa, carga de ateromas y leucopatía cerebral. RESULTADOS: Se estudiaron 145 sujetos (60.7 % mujeres, edad de 73 años). Se documentó ECA en 54.5 %, estenosis carotídea ≥ 50 % en 9 %, carga de placas de ateroma > 6 en 7.6 % y leucopatía periventricular o subcortical en 28.3 % (20.6 % tenían concurrentemente ECA y leucopatía). Los factores asociados independientemente con ECA fueron edad e hipertensión; con estenosis ≥ 50 %, hipertensión; con cargas de ateromas > 6 placas, edad; con leucopatía, edad, diabetes e hipertensión. La obesidad no se asoció con las variables independientes analizadas. CONCLUSIONES: En los sujetos asintomáticos sin historia de ictus isquémico, la edad y la hipertensión fueron los factores de riesgo más importantes para enfermedad macrovascular. La diabetes mellitus se asoció con enfermedad microvascular. La obesidad por sí sola no fue un determinante mayor de ECA o leucopatía cerebral.

Enhanced receptor-clathrin interactions induced by N-glycan-mediated membrane micropatterning.

Glycan-protein interactions are emerging as important modulators of membrane protein organization and dynamics, regulating multiple cellular functions. In particular, it has been postulated that glycan-mediated interactions regulate surface residence time of glycoproteins and endocytosis. How this precisely occurs is poorly understood. Here we applied single-molecule-based approaches to directly visualize the impact of glycan-based interactions on the spatiotemporal organization and interaction with clathrin of the glycosylated pathogen recognition receptor dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN). We find that cell surface glycan-mediated interactions do not influence the nanoscale lateral organization of DC-SIGN but restrict the mobility of the receptor to distinct micrometer-size membrane regions. Remarkably, these regions are enriched in clathrin, thereby increasing the probability of DC-SIGN-clathrin interactions beyond random encountering. N-glycan removal or neutralization leads to larger membrane exploration and reduced interaction with clathrin, compromising clathrin-dependent internalization of virus-like particles by DC-SIGN. Therefore, our data reveal that cell surface glycan-mediated interactions add another organization layer to the cell membrane at the microscale and establish a novel mechanism of extracellular membrane organization based on the compartments of the membrane that a receptor is able to explore. Our work underscores the important and complex role of surface glycans regulating cell membrane organization and interaction with downstream partners.

Nanoclustering as a dominant feature of plasma membrane organization.

Early studies have revealed that some mammalian plasma membrane proteins exist in small nanoclusters. The advent of super-resolution microscopy has corroborated and extended this picture, and led to the suggestion that many, if not most, membrane proteins are clustered at the plasma membrane at nanoscale lengths. In this Commentary, we present selected examples of glycosylphosphatidyl-anchored proteins, Ras family members and several immune receptors that provide evidence for nanoclustering. We advocate the view that nanoclustering is an important part of the hierarchical organization of proteins in the plasma membrane. According to this emerging picture, nanoclusters can be organized on the mesoscale to form microdomains that are capable of supporting cell adhesion, pathogen binding and immune cell-cell recognition amongst other functions. Yet, a number of outstanding issues concerning nanoclusters remain open, including the details of their molecular composition, biogenesis, size, stability, function and regulation. Notions about these details are put forth and suggestions are made about nanocluster function and why this general feature of protein nanoclustering appears to be so prevalent.

Noninvasive ventilation for severely acidotic patients in respiratory intermediate care units : Precision medicine in intermediate care units.

BACKGROUND: Severe acidosis can cause noninvasive ventilation (NIV) failure in chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure (AHRF). NIV is therefore contraindicated outside of intensive care units (ICUs) in these patients. Less is known about NIV failure in patients with acute cardiogenic pulmonary edema (ACPE) and obesity hypoventilation syndrome (OHS). Therefore, the objective of the present study was to compare NIV failure rates between patients with severe and non-severe acidosis admitted to a respiratory intermediate care unit (RICU) with AHRF resulting from ACPE, COPD or OHS. METHODS: We prospectively included acidotic patients admitted to seven RICUs, where they were provided NIV as an initial ventilatory support measure. The clinical characteristics, pH evolutions, hospitalization or RICU stay durations and NIV failure rates were compared between patients with a pH ≥ 7.25 and a pH < 7.25. Logistic regression analysis was performed to determine the independent risk factors contributing to NIV failure. RESULTS: We included 969 patients (240 with ACPE, 540 with COPD and 189 with OHS). The baseline rates of severe acidosis were similar among the groups (45 % in the ACPE group, 41 % in the COPD group, and 38 % in the OHS group). Most of the patients with severe acidosis had increased disease severity compared with those with non-severe acidosis: the APACHE II scores were 21 ± 7.2 and 19 ± 5.8 for the ACPE patients (p < 0.05), 20 ± 5.7 and 19 ± 5.1 for the COPD patients (p < 0.01) and 18 ± 5.9 and 17 ± 4.7 for the OHS patients, respectively (NS). The patients with severe acidosis also exhibited worse arterial blood gas parameters: the PaCO2 levels were 87 ± 22 and 70 ± 15 in the ACPE patients (p < 0.001), 87 ± 21 and 76 ± 14 in the COPD patients, and 83 ± 17 and 74 ± 14 in the OHS patients (NS)., respectively Further, the patients with severe acidosis required a longer duration to achieve pH normalization than those with non-severe acidosis (patients with a normalized pH after the first hour: ACPE, 8 % vs. 43 %, p < 0.001; COPD, 11 % vs. 43 %, p < 0.001; and OHS, 13 % vs. 51 %, p < 0.001), and they had longer RICU stays, particularly those in the COPD group (ACPE, 4 ± 3.1 vs. 3.6 ± 2.5, NS; COPD, 5.1 ± 3 vs. 3.6 ± 2.1, p < 0.001; and OHS, 4.3 ± 2.6 vs. 3.7 ± 3.2, NS). The NIV failure rates were similar between the patients with severe and non-severe acidosis in the three disease groups (ACPE, 16 % vs. 12 %; COPD, 7 % vs. 7 %; and OHS, 11 % vs. 4 %). No common predictive factor for NIV failure was identified among the groups. CONCLUSIONS: ACPE, COPD and OHS patients with AHRF and severe acidosis (pH ≤ 7.25) who are admitted to an RICU can be successfully treated with NIV in these units. These results may be used to determine precise RICU admission criteria.

Lateral mobility of individual integrin nanoclusters orchestrates the onset for leukocyte adhesion.

Integrins are cell membrane adhesion receptors involved in morphogenesis, immunity, tissue healing, and metastasis. A central, yet unresolved question regarding the function of integrins is how these receptors regulate both their conformation and dynamic nanoscale organization on the membrane to generate adhesion-competent microclusters upon ligand binding. Here we exploit the high spatial (nanometer) accuracy and temporal resolution of single-dye tracking to dissect the relationship between conformational state, lateral mobility, and microclustering of the integrin receptor lymphocyte function-associated antigen 1 (LFA-1) expressed on immune cells. We recently showed that in quiescent monocytes, LFA-1 preorganizes in nanoclusters proximal to nanoscale raft components. We now show that these nanoclusters are primarily mobile on the cell surface with a small (ca. 5%) subset of conformational-active LFA-1 nanoclusters preanchored to the cytoskeleton. Lateral mobility resulted crucial for the formation of microclusters upon ligand binding and for stable adhesion under shear flow. Activation of high-affinity LFA-1 by extracellular Ca(2+) resulted in an eightfold increase on the percentage of immobile nanoclusters and cytoskeleton anchorage. Although having the ability to bind to their ligands, these active nanoclusters failed to support firm adhesion in static and low shear-flow conditions because mobility and clustering capacity were highly compromised. Altogether, our work demonstrates an intricate coupling between conformation and lateral diffusion of LFA-1 and further underscores the crucial role of mobility for the onset of LFA-1 mediated leukocyte adhesion.

The neck region of the C-type lectin DC-SIGN regulates its surface spatiotemporal organization and virus-binding capacity on antigen-presenting cells.

The C-type lectin DC-SIGN expressed on dendritic cells (DCs) facilitates capture and internalization of a plethora of different pathogens. Although it is known that DC-SIGN organizes in nanoclusters at the surface of DCs, the molecular mechanisms responsible for this well defined nanopatterning and role in viral binding remain enigmatic. By combining biochemical and advanced biophysical techniques, including optical superresolution and single particle tracking, we demonstrate that DC-SIGN intrinsic nanoclustering strictly depends on its molecular structure. DC-SIGN nanoclusters exhibited free, Brownian diffusion on the cell membrane. Truncation of the extracellular neck region, known to abrogate tetramerization, significantly reduced nanoclustering and concomitantly increased lateral diffusion. Importantly, DC-SIGN nanocluster dissolution exclusively compromised binding to nanoscale size pathogens. Monte Carlo simulations revealed that heterogeneity on nanocluster density and spatial distribution confers broader binding capabilities to DC-SIGN. As such, our results underscore a direct relationship between spatial nanopatterning, driven by intermolecular interactions between the neck regions, and receptor diffusion to provide DC-SIGN with the exquisite ability to dock pathogens at the virus length scale. Insight into how virus receptors are organized prior to virus binding and how they assemble into functional platforms for virus docking is helpful to develop novel strategies to prevent virus entry and infection.

The Inflammatory Biomarkers Behavior Profile of Patients Following Elective Degenerative Spine Surgery and Differences Compared to Those Coursing With a Postoperative Spinal Infection: Protocol for a Systematic Review.

BACKGROUND: The incidence of postoperative spinal infection (PSI) ranges from 0% to 10%, with devastating effects on the patient prognosis because of higher morbidity while increasing costs to the health care system. PSIs are elusive and difficult to diagnose, especially in the early postoperative state, because of confusing clinical symptoms, rise in serum biomarkers, or imaging studies. Current research on diagnosis has focused on serum biomarkers; nevertheless, most series rely on retrospective cohorts where biomarkers are studied individually and at different time points. OBJECTIVE: This paper presents the protocol for a systematic review that aims to determine the inflammatory biomarker behavior profile of patients following elective degenerative spine surgery and their differences compared to those coursing with PSIs. METHODS: The proposed systematic review will follow the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. This protocol was registered at PROSPERO on January 19, 2022. We will include studies related to biomarkers in adult patients operated on for degenerative spinal diseases and those developing PSIs. The following information will be extracted from the papers: (1) study title; (2) study author; (3) year; (4) evidence level; (5) research type; (6) diagnosis group (elective postoperative degenerative disease or PSI); (7a) region (cervical, thoracic, lumbosacral, and coccygeal); (7b) type of infection by anatomical or radiological site; (8) surgery type (including instrumentation or not); (9) number of cases; (10) mean age or individual age; (11) individual serum biomarker values from the preoperative state up to 90 days postoperative for both groups, including (10a) interleukin-6, (10b) presepsin, (10c) erythrocyte sedimentation rate, (10d) leukocyte count, (10e) neutrophil count, (10f) C-reactive protein, (10g) serum amyloid, (10h) white cell count, (10i) albumin, (10j) prealbumin, (10k) procalcitonin, (10l) retinol-associated protein, and (10m) Dickkopf-1; (11) postoperative days at symptoms or diagnosis; (12) type of organism; (13) day of starting antibiotics; (14) duration of treatment; and (15) any biases (including comorbidities, especially those affecting immunological status). All data on biomarkers will be presented graphically over time. RESULTS: No ethical approval will be required, as this review is based on published data and does not involve interaction with human participants. The search for this systematic review commenced in February 2021, and we expect to publish the findings in mid-2023. CONCLUSIONS: This study will provide the behavior profile of biomarkers for PSI and patients following elective surgery for degenerative spinal diseases from the preoperative period up to 90 days postoperative, providing cutoff values on the day of diagnosis. This research will provide clinicians with highly trustable cutoff reference values for PSI diagnosis. Finally, we expect to provide a basis for future research on biomarkers that help diagnose more accurately and in a timely manner in the early stages of illness, ultimately impacting the patient's physical and mental health, and reducing the disease burden. TRIAL REGISTRATION: PROSPERO CRD42022304645; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=304645. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/41555.

[Giant tongue leading to dysphagia in light chain amyloidosis patient]. / Lengua gigante condicionante de disfagia en paciente con amiloidosis de cadenas ligeras.

Introduction: Macroglossia as a clinical manifestation of systemic amyloidosis is a rare condition, occurring in less than 9% of all types of amyloidosis. The aim of this report is to present the diagnostic approach of a patient with macroglossia, providing a systematic approach and considering relevant diagnostic possibilities during their evaluation. Clinical case: We present the case of a 60-year-old man who presented with a progressively enlarging giant tongue for six months, causing dysphagia and reduced oral opening. A tongue biopsy was taken, which histopathologically exhibited homogenous eosinophilic amyloid-like material. Congo red staining showed amyloid material with red dye under light microscopy and apple-green birefringence under polarized light. Bone marrow biopsy showed 30% plasma cells, allowing for a definitive diagnosis of soft tissue amyloidosis. Although it is a benign lesion, localized amyloidosis should be differentiated from systemic forms. Conclusions: The approach of patients with macroglossia is complex due to the diagnostic possibilities, from endocrinological causes, neoplastic, and even by deposit; Being an isolated sign in a patient is a challenge in its approach, because the involvement of the airway is the main complication to avoid in these patients.

Introducción: la macroglosia, como manifestación clínica de la amiloidosis sistémica, es una condición poco frecuente, ya que ocurre en menos del 9% de todos los tipos de amiloidosis. El objetivo de este informe es presentar el abordaje diagnóstico de un paciente con macroglosia, proporcionando un enfoque sistemático y considerando las posibilidades diagnósticas relevantes durante su evaluación. Caso clínico: presentamos el caso de un hombre de 60 años que presentó una lengua gigante de crecimiento progresivo durante seis meses, lo que causó disfagia y reducción en la apertura oral. Se realizó una biopsia de la lengua, la cual histopatológicamente exhibió material homogéneo similar a un amiloide eosinofílico. La tinción de rojo Congo mostró material amiloide con colorante rojo bajo microscopía óptica y con birrefringencia verde manzana bajo luz polarizada. La biopsia de médula ósea mostró un 30% de células plasmáticas, lo que permitió realizar un diagnóstico definitivo de amiloidosis de tejidos blandos. Aunque se trata de una lesión benigna, la amiloidosis localizada debe diferenciarse de las formas sistémicas. Conclusiones: el abordaje de pacientes con macroglosia es complejo, debido a las diversas posibilidades diagnósticas, que incluyen causas endocrinológicas, neoplásicas e, incluso, por deposición de sustancias. Cuando se presenta como un signo aislado en un paciente, se convierte en un reto en su abordaje, ya que la principal complicación a evitar en estos pacientes es el compromiso de la vía aérea.

[Recurrent chronic Vogt-Koyanagi-Harada syndrome or sarcoidosis? A Gloomy diagnosis]. / ¿Síndrome de Vogt-Koyanagi-Harada crónico o sarcoidosis? Un diagnóstico sombrío.

Background: Vogt-Koyanagi-Harada syndrome (VKH) is a systemic disease that affects organs profuse in melanocytes, presenting with a chronic and diffuse bilateral granulomatous panuveitis, as well as neurological, auditory, and cutaneous manifestations. In this article, a systematic approach is presented for the diagnostic management of VKH syndrome, considering relevant diagnostic possibilities to rule out other entities that manifest similar symptoms. Clinical case: 71-year-old man with a long-standing history of vitiligo, who experienced visual loss in his right eye 6 months before his admission, along with bilateral hearing loss predominantly in the right ear. During his hospitalization, he presented with chronic headache, fever, and significant involuntary weight loss. Ophthalmological examination revealed that his right eye only perceived light and had hyperemic bulbar conjunctiva, while the left eye had a visual acuity of 20/200. The right fundus had scattered pigmentation, while the left had an edematous optic disc and right optic atrophy. Conclusions: The diagnosis of VKH syndrome is established by the presence of the 5 diagnostic criteria for complete disease, including retinal depigmentation, neurological alterations, and dermatological manifestations. Since patients can present with a wide variety of symptoms, initial differential diagnosis should be considered, which represents a diagnostic challenge.

Introducción: el síndrome de Vogt-Koyanagi-Harada (VKH) es una enfermedad sistémica que afecta a órganos ricos en melanocitos y se manifiesta con una panuveítis granulomatosa bilateral, crónica y difusa, así como con manifestaciones neurológicas, auditivas y cutáneas. En este artículo se presenta un enfoque sistemático para el abordaje diagnóstico del síndrome de VKH y se consideran las posibilidades diagnósticas relevantes para descartar otras entidades que se presentan con síntomas similares. Caso clínico: hombre de 71 años con antecedentes de vitiligo de larga data, quien experimentó una pérdida visual en su ojo derecho seis meses antes de su ingreso, junto con hipoacusia bilateral, predominantemente en el oído derecho. Durante su hospitalización, presentó cefalea crónica, fiebre y una significativa pérdida involuntaria de peso. En la exploración oftalmológica, el ojo derecho solo percibía luz y presentaba conjuntiva bulbar hiperémica, mientras que el ojo izquierdo tenía una agudeza visual de 20/200. El fondo del ojo derecho presentaba pigmentación dispersa, mientras que el izquierdo tenía una papila edematosa y atrofia óptica derecha. Conclusiones: el diagnóstico del síndrome de VKH se establece mediante la presencia de los 5 criterios diagnósticos para la enfermedad completa, incluida la hipopigmentación retiniana, las alteraciones neurológicas y las manifestaciones dermatológicas. Dado que los pacientes pueden presentar una amplia variedad de síntomas, el diagnóstico diferencial debe considerarse inicialmente, lo que representa un desafío diagnóstico.