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Neuropathology Of Neuro-Ophthalmic Disorders
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Schwannoma is a slow-growing, benign nerve sheath tumor accounting for less than 1% of the orbital tumors and arises from branches of nerves traversing the orbit such as oculomotor, trochlear or abducens.36–38 Due to complexity of orbital structures, it's difficult to point out the origin. Small tumors are asymptomatic, but as they grow they compress the nerve in which they arise and also the surrounding structures. Most of the patients are adult and proptosis is the commonest presentation. Lid swelling is another prominent feature. MRI is very sensitive neuro-imaging technique for diagnosis. Macroscopically, a schwannoma appears encapsulated mass with a homogeneous, grayish-white cut surface, which may contain areas of hemorrhage. Histologically, schwannoma shows hypo- and hypercellular areas (Figure 25.18a). The cells show nuclear palisading and Verocay body formation (Figure 25.18b). The individual cells show spindle-shaped nuclei with pointed ends. These cells express S-100 protein on immunostaining. Mitosis and necrosis are rarely found. Hyalinized blood vessels as well as secondary degenerative changes such as edema, variable cystic degeneration, and infiltration by foamy macrophages are common findings. Orbital schwannomas often extend into cavernous sinus. A complete surgical excision is usually curative.
Molecular Pathology
Published in Burkhard Madea, Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
Astrocytes are more resistant to hypoxic conditions than neurones. The S100 proteins have an A and B subunit and are small acidic calcium-binding proteins. S100B is highly specific for astrocytes, oligodendrocytes and ependymocytes in the central nervous system. Clinically, S100B seems to act as a serum marker of brain damage from cerebral injury and hypoxia/ischaemia. Li et al. [20] found that, in cases of asphyxiation due to neck compression, the number of astrocytes immunostained with anti-S100 or anti-GFAP was significantly decreased, compared with that for other asphyxiation and acute myocardial infarction. Reciprocally, serum S100B levels were significantly higher in asphyxiation by neck compression than in other types of asphyxiation. These observations imply that astrocytes and serum S100B would be available biomarkers for supporting the diagnosis of asphyxiation due to neck compression.
The Non-Hodgkin’s Lymphomas and Plasma Cell Dyscrasias
Published in Harold R. Schumacher, William A. Rock, Sanford A. Stass, Handbook of Hematologic Pathology, 2019
Lynne V. Abruzzo, L. Jeffrey Medeiros
Immunophenotypic studies have shown that T-CLL/PLL are neoplasms of mature T-cell lineage. The neoplastic cells express pan-T-cell antigens and the TCRα/β receptor. Aberrant T-cell immunophenotypes may be detected, but are uncommon. Approximately two-thirds of cases are CD4+ CD8-, 20% coexpress CD4 and CD8, and rare cases are CD4- CD8+. Occasional cases express S100 protein. As expected for mature neoplasms, TdT is negative. Immunoglobulins and B-cell antigens are negative.
Identification of hub genes and potential biomarkers of neutrophilic asthma: evidence from a bioinformatics analysis
Published in Journal of Asthma, 2023
Qibin Lin, Haiyang Ni, Jieying Zhong, Zhishui Zheng, Hanxiang Nie
Presently, the S100 protein family comprises at least 20 members that are involved in diverse functions, including cellular proliferation, differentiation, apoptosis, energy metabolism, and inflammation (26). S100A12 is a member of the S100 protein family. It is also known as S100/calgranulin C and exists both within and outside of cells (27). S100A12 is expressed in many inflammatory cells and is present in the greatest abundance in neutrophils (28). The S100A12 protein undergoes conformational rearrangement and activation (27). The activated S100A12 protein can activate cell surface receptors, such as receptor for advanced glycation end products (RAGE) and Toll-like receptor-4 (TLR-4), to promote inflammation (28). Jin Hyun Kang et al. found that S100A12 acts on airway epithelial cells to induce MUC5AC production, supporting the important role of S100 protein in the pathogenesis of obstructive airway diseases dominated by neutrophils (28). In addition, S100A12 is considered to be related to oxidative stress in local airway inflammation (29). It has been proven that the S100A12 protein participates in lung diseases (27). Our study found that the sputum S100A12 level could be used to discriminate NA patients from EA patients and healthy people, suggesting that sputum S100A12 is a potential biomarker of NA. Current clinical trials related to the S100 protein family are mainly focused on nonpulmonary diseases, such as rheumatoid arthritis (27). Our research suggests that anti-S100A12 antibodies may benefit NA patients, but further studies are warranted.
Circulating biomarkers of response to immunotherapy and immune-related adverse events
Published in Expert Review of Molecular Diagnostics, 2022
Zachary Garrison, Noah Hornick, Jeffrey Cheng, Rajan P. Kulkarni
As S100 proteins have only recently gained traction as a circulating biomarker for immune therapies, there are still many unanswered questions to investigate. Little is known regarding the cancers that are influenced by S100A8/A9. Melanoma remains one of the most commonly studied cancers in regard to S100A8/A9 influence [27]. There are also several other S100 proteins that have barely been researched in the same context as A8 and A9. The S100B protein has also become a protein of interest as a prognostic immune therapy biomarker [28,29]. Clarifying potential utility for the full complement of S100 proteins as well as determining thresholds for CBI response will be key steps to more effective clinical utilization of these proteins. A better understanding of when S100 protein levels are the most informative within the context of treatment timing is crucial for clinical use.
Immunological mechanisms underlying sterile inflammation in the pathogenesis of atherosclerosis: potential sites for intervention
Published in Expert Review of Clinical Immunology, 2021
Roland Truong, Finosh G. Thankam, Devendra K. Agrawal
S100 proteins have similar characteristics to that of HMGB1. S100 proteins act as DAMPs that interact with TLR2, TLR3, TLR4, and RAGE following their release from phagocytes and modulate cellular pro-inflammatory response via NF-κB pathway [100]. S100 proteins have a wide range of intra- and extracellular functions to regulate cell growth and death. It belongs to a calcium-binding cytosolic protein family comprising the subtypes S100A8, S100A9, and S100A12 which mediate vascular inflammation and atherosclerosis [101] where S100A12 is the most predictive of coronary heart disease in a prospective population-based cohort study [102]. However, the increased S100A8/A9 levels are the predicting factors for the future myocardial infarction, stroke, and cardiovascular death [103]. ApoE−/- S100A9−/- double knockout mice demonstrated reduction in aortic atherosclerosis [104]. Though neutrophils are relatively lower in number than monocytes/macrophages in atherosclerotic lesions, there is a larger abundance of S100A8/A9 in neutrophils than monocytes/macrophages.