Inhibition of Shikimate Kinase from Methicillin-Resistant Staphylococcus aureus by Benzimidazole Derivatives. Kinetic, Computational, Toxicological, and Biological Activity Studies.

Antimicrobial resistance (AMR) is one of the biggest threats in modern times. It was estimated that in 2019, 1.27 million deaths occurred around the globe due to AMR. Methicillin-resistant Staphylococcus aureus (MRSA) strains, a pathogen considered of high priority by the World Health Organization, have proven to be resistant to most of the actual antimicrobial treatments. Therefore, new treatments are required to be able to manage this increasing threat. Under this perspective, an important metabolic pathway for MRSA survival, and absent in mammals, is the shikimate pathway, which is involved in the biosynthesis of chorismate, an intermediate for the synthesis of aromatic amino acids, folates, and ubiquinone. Therefore, the enzymes of this route have been considered good targets to design novel antibiotics. The fifth step of the route is performed by shikimate kinase (SK). In this study, an in-house chemical library of 170 benzimidazole derivatives was screened against MRSA shikimate kinase (SaSK). This effort led to the identification of the first SaSK inhibitors, and the two inhibitors with the greatest inhibition activity (C1 and C2) were characterized. Kinetic studies showed that both compounds were competitive inhibitors with respect to ATP and non-competitive for shikimate. Structural analysis through molecular docking and molecular dynamics simulations indicated that both inhibitors interacted with ARG113, an important residue involved in ATP binding, and formed stable complexes during the simulation period. Biological activity evaluation showed that both compounds were able to inhibit the growth of a MRSA strain. Mitochondrial assays showed that both compounds modify the activity of electron transport chain complexes. Finally, ADMETox predictions suggested that, in general, C1 and C2 can be considered as potential drug candidates. Therefore, the benzimidazole derivatives reported here are the first SaSK inhibitors, representing a promising scaffold and a guide to design new drugs against MRSA.

Cardiovascular-specific mortality and risk factors in colorectal Cancer patients: A cohort study based on registry data of over 500,000 individuals in the US.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide, and recent studies have found that CRC patients are at increased risk for cardiovascular disease (CVD). This study aimed to investigate competing causes of death and prognostic factors among a large cohort of CRC patients and to describe cardiovascular-specific mortality in relation to the US standard population. METHODS: This registry-based cohort study identified patients diagnosed with CRC between 1973 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database in the US. Cumulative mortality functions, conditional standardized mortality ratios, and cause-specific hazard ratios were calculated. RESULTS: Of the 563,298 eligible CRC patients included in this study, 407,545 died during the follow-up period. CRC was the leading cause of death, accounting for 49.8% of all possible competing causes of death. CVD was the most common non-cancer cause of death, accounting for 17.8% of total mortality. This study found that CRC patients have a significantly increased risk of cardiovascular-specific mortality compared to the US standard population, with the risk increasing with age and extended survival time. CONCLUSION: This study highlights the need to develop multidisciplinary prevention and management strategies for CRC and CVD to improve CRC patients' survival and quality of life.

Human neutrophil elastase inhibitors: Classification, biological-synthetic sources and their relevance in related diseases.

BACKGROUND: Human neutrophil elastase is a multifunctional protease enzyme whose function is to break the bonds of proteins and degrade them to polypeptides or amino acids. In addition, it plays an essential role in the immune mechanism against bacterial infections and represents a key mediator in tissue remodeling and inflammation. However, when the extracellular release of this enzyme is dysregulated in response to low levels of its physiological inhibitors, it ultimately leads to the degradation of proteins, in particular elastin, as well as other components of the extracellular matrix, producing injury to epithelial cells, which can promote sustained inflammation and affect the innate immune system, and, therefore, be the basis for the development of severe inflammatory diseases, especially those associated with the cardiopulmonary system. OBJECTIVE: This review aims to provide an update on the elastase inhibitory properties of several molecules, either synthetic or biological sources, as well as their classification and relevance in related pathologies since a clear understanding of the function of these molecules with the inhibitory capacity of this protease can provide valuable information for the development of pharmacological therapies that manage to modify the prognosis and survival of various inflammatory diseases. METHODS: Collected data from scientific databases, including PubMed, Google Scholar, Science Direct, Nature, Wiley, Scopus, and Scielo. Articles published in any country and language were included. RESULTS: We reviewed and included 132 articles conceptualizing neutrophil elastase activity and known inhibitors. CONCLUSION: Understanding the mechanism of action of elastase inhibitors based on particular aspects such as their kinetic behavior, structure-function relationship, chemical properties, origin, pharmacodynamics, and experimental progress has allowed for a broad classification of HNE inhibitors.

Integrating single-cell and spatial transcriptomics reveals endoplasmic reticulum stress-related CAF subpopulations associated with chordoma progression.

BACKGROUND: With cancer-associated fibroblasts (CAFs) as the main cell type, the rich myxoid stromal components in chordoma tissues may likely contribute to its development and progression. METHODS: Single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, bulk RNA-seq, and multiplexed quantitative immunofluorescence (QIF) were used to dissect the heterogeneity, spatial distribution, and clinical implication of CAFs in chordoma. RESULTS: We sequenced here 72 097 single cells from 3 primary and 3 recurrent tumor samples, as well as 3 nucleus pulposus samples as controls using scRNA-seq. We identified a unique cluster of CAF in recurrent tumors that highly expressed hypoxic genes and was functionally enriched in endoplasmic reticulum stress (ERS). Pseudotime trajectory and cell communication analyses showed that this ERS-CAF subpopulation originated from normal fibroblasts and widely interacted with tumoral and immune cells. Analyzing the bulk RNA-seq data from 126 patients, we found that the ERS-CAF signature score was associated with the invasion and poor prognosis of chordoma. By integrating the results of scRNA-seq with spatial transcriptomics, we demonstrated the existence of ERS-CAF in chordoma tissues and revealed that this CAF subtype displayed the most proximity to its surrounding tumor cells. In subsequent QIF validation involving 105 additional patients, we confirmed that ERS-CAF was abundant in the chordoma microenvironment and located close to tumor cells. Furthermore, both ERS-CAF density and its distance to tumor cells were correlated with tumor malignant phenotype and adverse patient outcomes. CONCLUSIONS: These findings depict the CAF landscape for chordoma and may provide insights into the development of novel treatment approaches.

Tailored Coatings for Enhanced Performance of Zinc-Magnesium Alloys in Absorbable Implants.

Absorbable metals exhibit potential for next-generation temporary medical implants, dissolving safely in the body during tissue healing and regeneration. Their commercial incorporation could substantially diminish the need for additional surgeries and complications that are tied to permanent devices. Despite extensive research on magnesium (Mg) and iron (Fe), achieving the optimal combination of mechanical properties, biocompatibility, and controlled degradation rate for absorbable implants remains a challenge. Zinc (Zn) and Zn-based alloys emerged as an attractive alternative for absorbable implants, due to favorable combination of in vivo biocompatibility and degradation behavior. Moreover, the development of suitable coatings can enhance their biological characteristics and tailor their degradation process. In this work, four different biodegradable coatings (based on zinc phosphate (ZnP), collagen (Col), and Ag-doped bioactive glass nanoparticles (AgBGNs)) were synthesized by chemical conversion, spin-coating, or a combination of both on Zn-3Mg substrates. This study assessed the impact of the coatings on in vitro degradation behavior, cytocompatibility, and antibacterial activity. The ZnP-coated samples demonstrated controlled weight loss and a decreased corrosion rate over time, maintaining a physiological pH. Extracts from the uncoated, ZnP-coated, and Col-AgBGN-coated samples showed higher cell viability with increasing concentration. Bacterial viability was significantly impaired in all coated samples, particularly in the Col-AgBGN coating. This study showcases the potential of a strategic material-coating combination to effectively tackle multiple challenges encountered in current medical implant technologies by modifying the properties of absorbable metals to tailor patient treatments.

A breast cancer classification and immune landscape analysis based on cancer stem-cell-related risk panel.

This study sought to identify molecular subtypes of breast cancer (BC) and develop a breast cancer stem cells (BCSCs)-related gene risk score for predicting prognosis and assessing the potential for immunotherapy. Unsupervised clustering based on prognostic BCSC genes was used to determine BC molecular subtypes. Core genes of BC subtypes identified by non-negative matrix factorization algorithm (NMF) were screened using weighted gene co-expression network analysis (WGCNA). A risk model based on prognostic BCSC genes was constructed using machine learning as well as LASSO regression and multivariate Cox regression. The tumor microenvironment and immune infiltration were analyzed using ESTIMATE and CIBERSORT, respectively. A CD79A+CD24-PANCK+-BCSC subpopulation was identified and its spatial relationship with microenvironmental immune response state was evaluated by multiplexed quantitative immunofluorescence (QIF) and TissueFAXS Cytometry. We identified two distinct molecular subtypes, with Cluster 1 displaying better prognosis and enhanced immune response. The constructed risk model involving ten BCSC genes could effectively stratify patients into subgroups with different survival, immune cell abundance, and response to immunotherapy. In subsequent QIF validation involving 267 patients, we demonstrated the existence of CD79A+CD24-PANCK+-BCSC in BC tissues and revealed that this BCSC subtype located close to exhausted CD8+FOXP3+ T cells. Furthermore, both the densities of CD79A+CD24-PANCK+-BCSCs and CD8+FOXP3+T cells were positively correlated with poor survival. These findings highlight the importance of BCSCs in prognosis and reshaping the immune microenvironment, which may provide an option to improve outcomes for patients.

A novel immune checkpoint-related signature for prognosis and immune analysis in breast cancer.

Breast cancer is one of the most prevailing forms of cancer globally. Immunotherapy has demonstrated efficacy in improving the overall survival of breast cancer. The aim of us was to formulate a novel signature predicated on immune checkpoint-related genes (ICGs) that could anticipate the prognosis and further analyze the immune status of patients with breast cancer. After acquiring data, we pinpointed the definitive ICGs for constructing the prognostic model of breast cancer. We constructed a novel prognostic model and created a fresh risk score called Immune Checkpoint-related Risk Score in breast cancer (ICRSBC). The nomogram was constructed to evaluate the accuracy of the model, and the new web-based tool was created to be more intuitive for predicting prognosis. We also investigated immunotherapy responsiveness and analyzed the tumor mutational burden (TMB) in ICRSBC subgroups. The ICRSBC was found to have significant correlations with the immune environment, immunotherapy responsiveness, and TMB. The expression levels of the 9 ICGs that construct the prognostic model and their promoter methylation levels are significantly different between breast cancer and normal tissues. Furthermore, the mutation profiles, the copy number alterations, and the levels of protein expression also exhibit marked disparities among the 9 ICGs. We have identified and validated a novel signature related to ICGs that is strongly associated with breast cancer progression. This signature enables us to create a risk score for prognosticating the survival and assessing the immune status of individuals affected by breast cancer.

Molecular Bases of Protein Antigenicity and Determinants of Immunogenicity, Anergy, and Mitogenicity.

BACKGROUND: The immune system is able to recognize substances that originate from inside or outside the body and are potentially harmful. Foreign substances that bind to immune system components exhibit antigenicity and are defined as antigens. The antigens exhibiting immunogenicity can induce innate or adaptive immune responses and give rise to humoral or cell-mediated immunity. The antigens exhibiting mitogenicity can cross-link cell membrane receptors on B and T lymphocytes leading to cell proliferation. All antigens vary greatly in physicochemical features such as biochemical nature, structural complexity, molecular size, foreignness, solubility, and so on. OBJECTIVE: Thus, this review aims to describe the molecular bases of protein-antigenicity and those molecular bases that lead to an immune response, lymphocyte proliferation, or unresponsiveness. CONCLUSION: The epitopes of an antigen are located in surface areas; they are about 880-3,300 Da in size. They are protein, carbohydrate, or lipid in nature. Soluble antigens are smaller than 1 nm and are endocytosed less efficiently than particulate antigens. The more the structural complexity of an antigen increases, the more the antigenicity increases due to the number and variety of epitopes. The smallest immunogens are about 4,000-10,000 Da in size. The more phylogenetically distant immunogens are from the immunogen-recipient, the more immunogenicity increases. Antigens that are immunogens can trigger an innate or adaptive immune response. The innate response is induced by antigens that are pathogen-associated molecular patterns. Exogenous antigens, T Dependent or T Independent, induce humoral immunogenicity. TD protein-antigens require two epitopes, one sequential and one conformational to induce antibodies, whereas, TI non-protein-antigens require only one conformational epitope to induce low-affinity antibodies. Endogenous protein antigens require only one sequential epitope to induce cell-mediated immunogenicity.

Ultrasound identification of the cricothyroid membrane. Systematic review and meta-analysis

Introduction: The no-ventilation no-oxygenation situation is extremely important due to its high mortality. In these cases, open cricothyroidotomy is indicated. Around fifty percent of the difficulties are the result of inadequate identification of the cricothyroid membrane (CTM). Objective: To determine whether ultrasonography is superior to palpation to identify the CTM at the first attempt. Methods: A systematic review and a meta-analysis were conducted on the identification of the cricothyroid membrane versus palpation in Medline/Central and Embase. Clinical controlled trials and observational studies were included. Two authors independently and in duplicate selected the studies, assessed the biases and extracted the data; a random effects meta-analysis was successfully conducted for the correct identification of the CTM. The risk of bias was assessed and the certainty of the evidence was qualified. CRD42021223961. Results: 464 studies were included of which 15 met the eligibility criteria; 6 were clinical trials y 9 were observational. Ultrasound is superior to palpation in the detection of the CTM (RR 1.88, 95 % CI 1.05-3.36) according to the clinical trials, and it was also superior in observational studies (RR 1.76, 95 % CI 1.36-2.28). The association was preserved in the sensitivity analyses. Conclusions: Ultrasonography is superior to palpation for the correct identification of the TCM, though the certainty of the evidence is low. Further studies with better methodology are needed to improve both certainty and precision.

Introducción: La situación de no ventilación-no oxigenación es de gran importancia dada su elevada mortalidad. En dichos casos, la cricotiroidotomía abierta está indicada. Cerca de la mitad de las dificultades son causadas por inadecuada identificación de la membrana cricotiroidea (MCT). Objetivo: Determinar si la ultrasonografía es superior a la palpación para identificar la MCT al primer intento. Métodos: Se realizó una revisión sistemática y metaanálisis de identificación de membrana cricotiroidea versus palpación en Medline/Central y Embase. Se incluyeron ensayos clínicos controlados y estudios observacionales. Dos autores de manera independiente y por duplicado realizaron la selección de estudios, la evaluación de sesgos y la extracción de datos, se efectuó un metaanálisis de efectos aleatorios con el éxito de identificación correcta de la MCT. Se evaluó el riesgo de sesgos y se calificó la certeza de la evidencia. CRD42021223961. Resultados: Se incluyeron 464 estudios de los cuales 15 cumplieron criterios de elegibilidad, 6 fueron ensayos clínicos y 9 observacionales. La ecografía es superior a la palpación para detección de la MCT (RR 1,88, IC 95 % 1,05-3,36) según los ensayos clínicos y, similarmente, fue superior para los estudios observacionales (RR 1,76, IC 95 % 1,36-2,28); la asociación se conservó en los análisis de sensibilidad. Conclusiones: La ultrasonografía es superior a la palpación para detectar correctamente la MCT, aunque con baja certeza de la evidencia. Se requieren más estudios con mejor calidad metodo-lógica para mejorar la certeza y la precisión.

Microcomputed tomography visualization and quantitation of the pulmonary arterial microvascular tree in mouse models of chronic lung disease.

Pulmonary vascular dysfunction is characterized by remodeling and loss of microvessels in the lung and is a major manifestation of chronic lung diseases (CLD). In murine models of CLD, the small arterioles and capillaries are the first and most prevalent vessels that are affected by pruning and remodeling. Thus, visualization of the pulmonary arterial vasculature in three dimensions is essential to define pruning and remodeling both temporally and spatially and its role in the pathogenesis of CLD, aging, and tissue repair. To this end, we have developed a novel method to visualize and quantitate the murine pulmonary arterial circulation using microcomputed tomography (µCT) imaging. Using this perfusion technique, we can quantitate microvessels to approximately 6 µM in diameter. We hypothesize that bleomycin-induced injury would have a significant impact on the arterial vascular structure. As proof of principle, we demonstrated that as a result of bleomycin-induced injury at peak fibrosis, significant alterations in arterial vessel structure were visible in the three-dimensional models as well as quantification. Thus, we have successfully developed a perfusion methodology and complementary analysis techniques, which allows for the reconstruction, visualization, and quantitation of the mouse pulmonary arterial microvasculature in three-dimensions. This tool will further support the examination and understanding of angiogenesis during the development of CLD as well as repair following injury.

HER2+ esophageal carcinoma leptomeningeal metastases treated with intrathecal trastuzumab regimen.

Materials & methods: We recently reported the largest trial of breast cancer patients with HER2 positive leptomeningeal metastases (LM) treated with trastuzumab. An additional treatment indication was explored as part of a single institution retrospective case series of HER2 positive esophageal adenocarcinoma LM (n = 2). Results: One patient received intrathecal trastuzumab (80 mg twice weekly) as part of their treatment regimen with durable long-term response and clearance of circulating tumor cells in the cerebral spinal fluid. The other patient demonstrated rapid progression and death as previously described in the literature. Conclusion: Intrathecal trastuzumab is a well-tolerated and reasonable therapeutic option worthy of further exploration for patients with HER2 positive esophageal carcinoma LM. An associative, but not a causal relationship, can be made regarding therapeutic intervention.

Cancer of the esophagus, the tube that connects the mouth to the stomach, tends to be aggressive. Very rarely, this cancer can spread to the lining that surrounds your brain, called the leptomeninges. Previous reports of patients who have experienced this specific spreading pattern of esophageal cancer to the leptomeninges are quite grim, with patients experiencing rapid decline and death within weeks to months. However, we write with two cases of esophageal cancer with this leptomeningeal spreading pattern, one of which involves a patient treated with a medication known as trastuzumab. As part of his long and complex course of treatment, this patient was given trastuzumab through a tube traveling directly to the area of the leptomeninges. This patient, now almost 2 years out from his initial diagnosis, has responded well to the treatment. As such, we believe that this specific treatment regimen as well as the ways in which our clinical team tracked this patient's response to medications are worth exploring further.

High-Density IgG4+ Plasma Cells Infiltration Is Associated With Fibroplasia in Fibrostenotic Crohn's Disease.

Transmural fibrosis and stricture formation are key pathogenic processes for Crohn's disease that underlies clinical refractoriness, resulting in severe morbidity. The mechanisms for fibroplasia in Crohn's are not fully elucidated. In this study, we identified a cohort of refractory Crohn's disease with surgically resected bowel specimens including cases with bowel stricture and age-/sex-matched refractory disease without bowel stricture. Via immunohistochemistry, density and distribution of IgG4+ plasma cells in resected cases were analyzed. The histologic severity of fibrosis and association with gross evidence of stricture formation and IgG4+ plasma cells were comprehensively analyzed. Our results showed that density of IgG4+ plasma cells/high-power field (IgG4+ PCs/HPF) was significantly associated with increasing histologic fibrosis score (15 IgG4+ PCs/HPF in specimens with fibrosis score 0 vs 31 IgG4+ PC/HPF in fibrosis score 2 and 3, P = .039). Patients with gross evidence of stricture had significantly higher fibrosis scores compared to those without gross evidence of stricture (P = .044). There was a trend that mean IgG4+ plasma cell count was higher in Crohn's disease with gross stricture formation (P = .26), although it did not reach statistical significance (likely due to multiple pathogenesis events involved in bowel stricture formation besides IgG4+ plasma cells; such as transmural fibrosis, muscular hypertrophy, transmural ulcer/scar formation, and muscular-neural dysfunction). Our findings indicate IgG4+ plasma cells are associated with increasing histologic fibrosis in Crohn's. Further research is needed to establish a role for IgG4+ plasma cells in fibroplasia with an eye toward potential medical therapies targeting IgG4+ plasma cells to prevent transmural fibrosis.

"Imaging Findings of Eosinophilic Gastrointestinal Diseases in Adults".

Eosinophilic gastrointestinal (GI) disorders are a group of conditions marked by pathologic eosinophilic infiltration of one or multiple locations in the GI tract. Conditions include eosinophilic esophagitis, eosinophilic gastritis, eosinophilic enteritis, and eosinophilic colitis. The site and depth of eosinophilic infiltration of the GI tract usually determines clinical presentation. These conditions should be considered in the differential diagnosis for several GI symptoms, such as food impaction or dysphagia. Histopathology is the gold standard for diagnosis of eosinophilic disorders. Nevertheless, findings from endoscopy, barium studies, computed tomography or magnetic resonance imaging, can aid in the diagnosis, by allowing for earlier diagnosis as well as proper management. Eosinophilic gastrointestinal disorders are typically managed with corticosteroids or dietary elimination. A high index of suspicion is required for diagnosis as it can often be challenging.

The role of the biomechanics analyst in swimming training and competition analysis.

Swimming analysts aid coaches and athletes in the decision-making by providing evidence-based recommendations. The aim of this narrative review was to report the best practices of swimming analysts that have been supporting high-performance athletes. It also aims to share how swimming analysts can translate applied research into practice. The role of the swimming analyst, as part of a holistic team supporting high-performance athletes, has been expanding and is needed to be distinguished from the job scope of a swimming researcher. As testing can be time-consuming, analysts must decide what to test and when to conduct the evaluation sessions. Swimming analysts engage in the modelling and forecast of the performance, that in short- and mid-term can help set races target-times, and in the long-term provide insights on talent and career development. Races can be analysed by manual, semi-automatic or fully automatic video analysis with single or multi-cameras set-ups. The qualitative and quantitative analyses of the swim strokes, start, turns, and finish are also part of the analyst job scope and associated with race performance goals. Land-based training is another task that can be assigned to analysts and aims to enhance the performance, prevent musculoskeletal injuries and monitor its risk factors.

Immunomodulatory Activity of Diterpenes over Innate Immunity and Cytokine Production in a Human Alveolar Epithelial Cell Line Infected with Mycobacterium tuberculosis.

BACKGROUND: Mexico has the largest number of the genus salvia plant species, whose main chemical compounds of this genus are diterpenes, these chemical compounds have shown important biological activities such as: antimicrobial, anti-inflammatory and immunomodulatory. OBJECTIVE: This study aimed to evaluate the immunomodulatory activity of three diterpenes: 1) icetexone, 2) anastomosine and 3) 7,20-dihydroanastomosine, isolated from Salvia ballotiflora, over innate immunity and cytokine production in a human alveolar epithelial cell line infected with Mycobacterium tuberculosis. METHODS: The immunomodulatory activity of diterpenes over innate immunity included reactive oxygen and nitrogen species (ROS and RNS) induction in response to infection; cytokine production included TNF-α and TGF-ß induction in response to infection. RESULTS: The diterpenes anastomosine and 7,20-dihydroanastomosine showed a statically significant (p < 0.01) increase of RNS after 36 h of infection and treatment of 2.0 µg/mL. Then, the ROS induction in response to infection showed a consistent statically significant (p < 0.01) increase after 12 h of diterpenes treatments. The cell cultures showed an anti-inflammatory effect, in the case of TGF-ß induction, in response to infection when treated with the diterpenes. On the other hand, there was not any significant effect on TNF-α release. CONCLUSION: The diterpenes anastomosine and 7,20-dihydroanastomosine increased the production of RNS after 36 h of infection and treatment. Besides, the three diterpenes increased the production of ROS after 12 h. This RNS and ROS modulation can be considered as an in vitro correlation of innate immunity in response to Mycobacterium tuberculosis infection; and an indicator of the damage of epithelial lung tissue. This study also showed an anti-inflammatory immune response by means of TGF-ß modulation when compared with control group.

Tannic Acid, as a Structural Moiety Coupled to a Protein Antigen, Exhibiting a Molecular-structure Adjuvant Activity for Antibody Specificity Enhancement.

BACKGROUND: An antigen is a small foreign substance, such as a microorganism structural protein, that may trigger an immune response once inside the body. Antigens are preferentially used rather than completely attenuated microorganisms to develop safe vaccines. Unfortunately, not all antigens are able to induce an immune response. Thus, new adjuvants to enhance the antigen's ability to stimulate immunity must be developed. OBJECTIVES: Therefore, this work aimed to evaluate the molecular-structure adjuvant activity of tannic acid (TA) coupled to a protein antigen in Balb/c mice. METHODS: Bovine serum albumin (BSA) was used as an antigen. The coupling of BSA and TA was mediated by carbodiimide crosslinking, and verified by SDS-PAGE. Forty-two Balb/c mice were divided into seven groups, including two controls without antigen, an antigen control, an adjuvant control, and two treatment groups. An additional group was used for macrophages isolation. A 30-day scheme was used to immunize the mice. The analysis of humoral immunity included immunoglobulin quantification, isotyping and antigen-antibody precipitation. The analysis of cell-mediated immunity included the quantification of nitric oxide from peritoneal macrophages and splenocytes' proliferation assay after treatment stimulation. RESULTS: No differences were found in the antibodies' concentration or isotypes induced with the conjugate or the pure BSA. However, an immunogenicity improvement (p < 0.05) was observed through the specific anti-BSA antibody titers in mice immunized with the conjugate. Besides, macrophage activation (p < 0.05) was detected when stimulated with the treatments containing TA. CONCLUSION: Tannic acid exhibited macrophages' activation properties. Moreover, when TA was incorporated into the structure of a protein antigen, such as BSA, an antibody specificity enhancement was observed. This was a consequence of antigen processing by activated antigen-presenting cells. These results showed the use of tannic acid as a novel candidate for vaccine molecular-structure adjuvant.

Race analysis of the men's 50 m events at the 2021 LEN European Championships.

The aim of this study was to: (i) characterise the stroke kinematics' stability of the male swimmers competing in the four 50 m events at the 2021 European Championships, and; (ii) understand the speed-time relationship in the four race events. All male swimmers who participated in the 50 m events (backstroke: 78 swimmers; breaststroke: 79 swimmers; butterfly: 89 swimmers; freestyle: 95 swimmers) were evaluated. In each swimming stroke swimmers were split in two groups (better and poorer performances). Significant variances (p < 0.05) were observed in both groups in all variables and for all swimming strokes. Swimming speed was the variable with the highest variance in both groups and strokes. Overall, better swimmers presented a low to high normative stability, and poorer swimmers a moderate-to-high. Speed-time curve fitting for all swimming strokes and groups suggested a cubic relationship. It can be considered that elite male swimmers racing 50 m sprint events at major competitions present an all-out trend. The present data provide coaches with substantial information about the main trend in the 50 m sprint events, specifically in each section of the race.

Histologic Variants of Kaposi Sarcoma in the Gastrointestinal Tract: A Contemporary Multi-institutional Clinicopathologic Analysis of 46 Cases.

Kaposi sarcoma (KS) can pose diagnostic challenges in biopsy specimens. Multiple histologic variants of cutaneous KS have been described; however, the histomorphologic spectrum of gastrointestinal (GI) KS has not been systematically studied. This large series comprehensively evaluated 46 cases of KS involving the GI tract and identified 7 histomorphologic variants, some that have not been previously described. Five of them are inconspicuous but have unique morphologic patterns, including lymphangioma/lymphangiectatic-like (n=17), mucosal hemorrhage/telangiectatic-like (n=17), mucosal inflammation-like (n=15), granulation tissue-like (n=13), and mucosal prolapse-like (n=4) variants. These variants can be easily misdiagnosed or misinterpreted on routine examination if KS is not considered, and if the immunohistochemical stain for human herpesvirus-8 is not performed. The other 2 morphologic variants present as spindle cell proliferations and are the GI stromal tumor-like (n=8) and inflammatory myofibroblastic tumor-like (n=2). These variants raise a broad differential diagnosis of spindle cell tumors of the GI tract and could pose diagnostic challenges. In summary, GI KS lesions exhibit variable, often unconventional histomorphologic patterns. KS should be included in the differential diagnosis even if features of conventional KS are not seen, particularly in limited biopsies in immunocompromised patients, such as those with human immunodeficiency virus infection. Although the clinical significance of these morphologic variants is yet to be determined, they are nonetheless important from a diagnostic standpoint. Misdiagnosis and delay in appropriate management can be avoided by recognizing the morphologic diversity of GI KS and appropriately utilizing the human herpesvirus-8 immunohistochemical stain.

Overexpression of programmed death ligand 1 in refractory inflammatory bowel disease.

Programmed death ligand 1 (PD-L1) dysregulation has been implicated in chronic inflammatory diseases, but its role in regulating intestinal mucosa inflammation is still unclear. The aim of this study was to assess PD-L1 expression in the intestinal mucosa of patients with refractory inflammatory bowel disease (IBD) compared to controls. We evaluated PD-L1 expression by immunohistochemistry in colectomy specimens of patients with ulcerative colitis (UC) and Crohn disease (CD) compared to controls. PD-L1 expression was assessed in colonic epithelium and inflammatory cells, along with the location of the inflammatory cells expressing PD-L1. All cases were stained with CD3, CD4, CD8, FOXP3, CD20, CD68, and CD90 immunostains to determine the types of cells expressing PD-L1. The UC group showed significantly higher PD-L1 expression in the colonic epithelium than both CD and control groups (both P < 0.001), and CD was also significantly higher than the control group (P = 0.004). Both UC and CD groups showed similar PD-L1 expression in the inflammatory infiltrate but significantly higher than the control group (both P < 0.001). Among both IBD groups, higher IBD activity was associated with higher levels of PD-L1 expression in the colonic epithelium (P < 0.05) and inflammatory infiltrate (P < 0.001). When comparing PD-L1 expression to lineage-specific markers, CD3+, CD4+ T cells, CD68+ macrophages, and CD90+ colonic stromal cells appeared to be expressing PD-L1. These findings implicate a role for PD-L1 in the dysregulation of the immune response in refractory IBD. Further studies are warranted to better understand the role of the immune regulatory pathways in intestinal mucosa.

The Possible Pathogenic Role of IgG4-Producing Plasmablasts in Stricturing Crohn's Disease.

BACKGROUND: Crohn's disease (CD) is a condition on the spectrum of inflammatory bowel disease that affects up to 20 people per 100,000 in the US annually, and with incidence increasing. One of the most significant sources of morbidity in CD is the formation of strictures, with resultant intestinal blockage a common indication for hospitalization and surgical intervention in these patients. The pathophysiology of stricture formation is not fully understood. However, the fibroplasia that leads to fibrostenotic stricture formation may have shared pathophysiology with IgG4-related fibrosis. SUMMARY: Initial intestinal inflammation recruits innate immune cells, such as neutrophils, that secrete IL-1ß and IL-23, which induces a type 17 CD4+ T-helper T-cell (Th17)-mediated adaptive immune response. These CD4+ Th17 T cells also contribute to inflammation by secreting proinflammatory cytokines such as IL-17 and IL-21. IL-21 recruits and stimulates CD4+ T follicular helper (Tfh) cells, which secrete more IL-21. This causes ectopic germinal center formation, recruiting and stimulating naïve B cells. The IL-17 and IL-21 produced by Th17 cells and Tfh cells also induce IgG4 plasmablast differentiation. Finally, these IgG4-producing plasmablasts secrete platelet-derived growth factor (PDGF), which activates local PDGF-receptor expressing fibroblasts and myofibroblasts, resulting in uncontrolled fibroplasia.