A Unique Case Report of Infant-Type Hemispheric Glioma (Gliosarcoma Subtype) with TPR-NTRK1 Fusion Treated with Larotrectinib

Herein, we present a rare case of a nine-month-old boy diagnosed with infant-type hemispheric glioma (gliosarcoma subtype) at the left frontal lobe. Following subtotal resection, the patient started chemotherapy with the BABY POG protocol. We describe the clinical diagnosis, histological characteristics, radiological features, molecular aspects, and management of this tumor. A comprehensive molecular analysis on the tumor tissue showed a <i>TPR-NTRK1</i> gene fusion. The patient was treated with a TRK inhibitor, larotrectinib, and exhibited a stable disease with residual lesion following 8 months of target therapy. The present study is the first report of an infantile gliosarcoma harboring <i>NTRK1</i> rearrangement treated with larotrectinib.

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

<b><i>Background:</i></b> 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. <b><i>Summary:</i></b> Initial intestinal inflammation recruits innate immune cells, such as neutrophils, that secrete IL-1β 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.

Digital Technology in Diagnostic Breast Pathology and Immunohistochemistry

Digital technology has been used in the field of diagnostic breast pathology and immunohistochemistry (IHC) for decades. Examples include automated tissue processing and staining, digital data processing, storing and management, voice recognition systems, and digital technology-based production of antibodies and other IHC reagents. However, the recent application of whole slide imaging technology and artificial intelligence (AI)-based tools has attracted a lot of attention. The use of AI tools in breast pathology is discussed briefly as it is covered in other reviews. Here, we present the main application of digital technology in IHC. This includes automation of IHC staining, using image analysis systems and computer vision technology to interpret IHC staining, and the use of AI-based tools to predict marker expression from haematoxylin and eosin-stained digitalized images.

Immunohistochemical and Transcriptional Analysis of SARS-CoV-2 Entry Factors and Renin-Angiotensin-Aldosterone System Components in Lethal COVID-19

<b><i>Introduction:</i></b> Since angiotensin converting enzyme-2 (ACE2) was discovered as an essential entry factor of SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2), there has been conflicting evidence regarding the role of renin-angiotensin-aldosterone system (RAAS) in COVID-19. This study elucidates pulmonary expression patterns SARS-CoV-2 entry factors (ACE2 and transmembrane protease serine subtype 2, TMPRSS2) and RAAS components in lethal COVID-19. <b><i>Methods:</i></b> Lung tissue from COVID-19 autopsies (<i>n</i> = 27) and controls (<i>n</i> = 23) underwent immunohistochemical staining for RAAS components (angiotensin receptors 1 and 2, ACE2 and Mas-receptor) and bradykinin receptors 1 and 2. Staining of individual cellular populations (alveolar pneumocytes [ALV], desquamated cells [DES] and endothelium [END]) was measured by a binary scale (positive/negative). SARS-CoV-2 was detected using immunohistochemistry against nucleocapsid protein, <i>in-situ</i> hybridization and quantitative reverse transcriptase polymerase chain reaction. Gene expression profiling for <i>ACE2, ACE</i> and <i>TMPRSS2</i> was performed. <b><i>Results:</i></b> Subtle differences were observed when comparing COVID-19 patients and controls not reaching statistical significance, such as a higher incidence of ACE2-positivity in END (52% vs. 39%) but lower positivity in ALVs (63% vs. 70%) and an overall downregulation of <i>ACE2</i> gene expression (0.25 vs. 0.55). However, COVID-19 patients with RAAS inhibitor (RAASi) intake had significantly shorter hospitalization times (5 vs. 12 days), higher viral loads (57,517 vs. 15,980/10⁶ RNase P-gene copies) and decreased <i>ACE/ACE2</i>-expression ratios (4.58 vs. 11.07) than patients without. <i>TMPRSS2</i> expression was significantly (1.76-fold) higher in COVID-19 patients than controls. <b><i>Conclusion:</i></b> Our study delineates the heterogeneous expression patterns of RAAS components in the lungs, which vary amongst cellular populations, and implies that COVID-19 patients with RAASi-intake present with a more rapid disease progression, although this requires further investigation.

Emodin Promotes Autophagy and Prevents Apoptosis in Sepsis-Associated Encephalopathy through Activating BDNF/TrkB Signaling

<b><i>Objective:</i></b> Sepsis-associated encephalopathy (SAE) is a severe and common complication of sepsis and can induce cognitive dysfunction and apoptosis of neurons and neuroinflammation. Emodin has been confirmed to have anti-inflammatory effects. Thus, we sought to investigate the role of Emodin in SAE. <b><i>Methods:</i></b> The cecal ligation and puncture (CLP) method was used for the establishment of SAE in mice model. For treatment of Emodin, intraperitoneal injection of 20 mg/kg Emodin was performed before the surgery. The Morris water maze and open field tests were carried for measurement of cognitive dysfunction. Hematoxylin and eosin staining was for histological analysis of hippocampus. Cell apoptosis of hippocampus neurons was measured by TUNEL staining. Pro-inflammatory and anti-inflammatory cytokines in hippocampus tissue homogenate were evaluated by ELISA. BDNF/TrkB signaling-related proteins (TrkB, p-TrkB, and BDNF), autophagy-related proteins (LC3 II/I and Beclin-1), and apoptosis-related proteins (Bax, Bcl-2, and cleaved caspase-3) were detected by Western blotting. <b><i>Results:</i></b> Emodin significantly inhibited apoptosis and induced autophagy in hippocampal neurons of CLP-treated mice. In addition, Emodin significantly ameliorated CLP-induced cognitive dysfunction and pathological injury in mice. Meanwhile, Emodin notably inhibited CLP-induced inflammatory responses in mice via upregulation of BDNF/TrkB signaling, while the effect of Emodin was partially reversed in the presence of K252a (BDNF/TrkB signaling inhibitor). <b><i>Conclusion:</i></b> Emodin significantly inhibited the progression of SAE via mediation of BDNF/TrkB signaling. Thus, Emodin might serve as a new agent for SAE treatment.

Elevated Myeloperoxidase-DNA Complex Levels in Sera of Patients with IgA Vasculitis

<b><i>Introduction:</i></b> IgA vasculitis is a systemic disease that results from the entrapment of circulating IgA-containing immune complexes in small-vessel walls in the skin, kidneys, and gastrointestinal tract. An excessive formation of neutrophil extracellular traps (NETs) is involved in the pathogenesis of vasculitis, especially in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. This study aimed to clarify whether NETs are implicated in IgA vasculitis. <b><i>Methods:</i></b> Twenty-two patients with IgA vasculitis and 4 healthy volunteers were enrolled in this study. Serum levels of myeloperoxidase (MPO)-DNA complex, a fragment derived from NETs, were determined by enzyme-linked immunosorbent assay (ELISA), and the association between MPO-DNA complex levels and clinical parameters was examined. The presence of the ANCA was also assessed by ELISA specific for MPO and proteinase 3 (PR3) and indirect immunofluorescence (IIF), followed by assessing the differences in clinical parameters with and without the ANCA. <b><i>Results:</i></b> Serum MPO-DNA complex levels were significantly higher in patients with IgA vasculitis than those in healthy controls. A significant positive correlation between the serum MPO-DNA complex and IgA levels was noted. Interestingly, 63.6% of IgA vasculitis patients were ANCA-positive in IIF with an atypical pattern, whereas neither MPO-ANCA nor PR3-ANCA was detected by ELISA. These findings indicated that some IgA vasculitis patients possessed the so called minor ANCA. Serum IgA and MPO-DNA complex levels and the frequency of hematuria in the minor ANCA-positive group were significantly higher than in the minor ANCA-negative group. <b><i>Conclusion:</i></b> The collective findings suggested that NETs are certainly involved in the pathogenesis of IgA vasculitis.

The Lipopolysaccharide Mutant Re-LPS Is a Useful Tool for Detecting LPS Contamination in Rheumatoid Synovial Cell Cultures

<b><i>Introduction:</i></b> Lipopolysaccharide (LPS) contamination of commercially available proteins has seriously impeded research on citrullinated fibrinogen (cit-Fb) in rheumatoid synovial cells (RSCs). <b><i>Methods:</i></b> RSCs obtained from 4 rheumatoid arthritis patients who underwent full knee arthroplasty were cultured, stimulated with cit-Fb, and cytokine expression levels were measured. We then evaluated polymyxin-B (PMB), heat inactivation, and rough (R)-type LPS mutants for rapid detection of LPS contamination. <b><i>Results:</i></b> cit-Fb induced expression of <i>CXCL10</i> and <i>IFNB</i> in RSCs via the toll-like receptor. PMB inhibited cit-Fb-mediated CXCL10 gene expression but not protein expression induced by 20 μg/mL cit-Fb. Heat inactivation did not affect LPS-mediated <i>CXCL10</i> or <i>IL-6</i> induction; however, cit-Fb-mediated <i>CXCL10</i>expression was inhibited. Wild-type LPS from <i>Escherichia coli</i> (WT-LPS) strongly induces <i>CXCL10</i> expression, but induction by Ra-LPS was weak, and induction by Rc- and Re-LPS was minimal. Re-LPS suppression of WT-LPS-mediated <i>CXCL10</i> induction in RSCs and peripheral blood monocytes (PBMs) was dose dependent. Furthermore, Re-LPS completely suppressed cit-Fb-mediated <i>CXCL10</i> induction in RSCs and PBMs. <b><i>Conclusion:</i></b> To easily identify LPS contamination during routine experiments, our results suggest that Re-LPS is a better tool for rapid detection of LPS contamination compared to PMB and heat treatment.

Increase in Chondroitin Sulfate and Decline in Arylsulfatase B May Contribute to Pathophysiology of COVID-19 Respiratory Failure

<b><i>Introduction:</i></b> The potential role of accumulation of chondroitin sulfates (CSs) in the pathobiology of COVID-19 has not been examined. Accumulation may occur by increased synthesis or by decline in activity of the enzyme arylsulfatase B (ARSB; N-acetylgalactosamine-4-sulfatase) which requires oxygen for activity. <b><i>Methods:</i></b> Immunostaining of lung tissue from 28 patients who died due to COVID-19 infection was performed for CS, ARSB, and carbohydrate sulfotransferase (CHST)15. Measurements of mRNA expression of CHST15 and CHST11, sulfotransferase activity, and total sulfated glycosaminoglycans (GAGs) were determined in human vascular smooth muscle cells following angiotensin (Ang) II treatment. <b><i>Results:</i></b> CS immunostaining showed increase in intensity and distribution, and immunostaining of ARSB was diminished in COVID-19 compared to normal lung tissue. CHST15 immunostaining was prominent in vascular smooth muscle cells associated with diffuse alveolar damage due to COVID-19 or other causes. Expression of CHST15 and CHST11 which are required for synthesis of CSE and chondroitin 4-sulfate, total sulfated GAGs, and sulfotransferase activity was significantly increased following AngII exposure in vascular smooth muscle cells. Expression of Interleukin-6 (IL-6), a mediator of cytokine storm in COVID-19, was inversely associated with ARSB expression. <b><i>Discussion/Conclusion:</i></b> Decline in ARSB and resulting increases in CS may contribute to the pathobiology of COVID-19, as IL-6 does. Increased expression of CHSTs following activation of Ang-converting enzyme 2 may lead to buildup of CSs.

Microsatellite Instability Is Rare in the Admixed Brazilian Population of Non-Small Cell Lung Cancer: A Cohort of 526 Cases

Background: Microsatellite instability (MSI) in non-small cell lung cancer (NSCLC) is uncommon; however, most studies refer to European and Asian populations. There are currently no data on MSI frequency in highly admixed populations, such as the one represented by Brazilian NSCLC patients. Aim: This study aimed to evaluate the frequency of MSI in Brazilian NSCLC patients. Methods: We evaluated 526 patients diagnosed with NSCLC at the Barretos Cancer Hospital (Brazil). The molecular MSI evaluation was performed using a hexa-plex marker panel by polymerase chain reaction followed by fragment analysis. The mutation profile of MSI-positive cases was performed using next-generation sequencing. Results: Only 1 patient was MSI positive (0.19%). This patient was a female, white, and active smoker, and she was diagnosed with clinical stage IV lung adenocarcinoma at 75 years old. The molecular profile exhibited 4 Tumor Protein p53 (TP53) mutations and the absence of actionable mutations in the Epidermal Growth Factor Receptor (EGFR), Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS), or V-Raf Murine Sarcoma Viral Oncogene Homolog B1 (BRAF) genes. Conclusions: The frequency of MSI in Brazilian NSCLC patients is equally rare, a finding that is consistent with the current literature based on other populations such as Europeans, North Americans, and Asians.

miR-31-5p/SOX4 Axis Affects Autophagy and Apoptosis of Chondrocytes by Regulating Extracellular Regulated Protein Kinase/Mechanical Target of Rapamycin Kinase Signalling

<b><i>Background:</i></b> Osteoarthritis (OA) is a common type of degenerative joint diseases that is regulated by a combination of complex intercellular signals and modulators, including non-coding RNAs. Mounting evidence suggests that miR-31-5p is physiologically involved in the regulation of chondrocytes, but the mechanism remains unclear. <b><i>Methods:</i></b> Expression levels of miR-31-5p and SOX4 in OA cartilage tissues and in IL-1β-stimulated chondrocytes were examined by quantification polymerase chain reaction (q-PCR) or immunohistochemistry assays. Cell proliferation and apoptosis were detected by Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. Expression of LC3 was detected using immunofluorescence staining. Expressions of autophagy-related proteins and extracellular regulated protein kinase (ERK)/mechanical target of rapamycin kinase (mTORC1) signal-related proteins were measured by Western blot analysis. Molecular interaction was validated by dual luciferase reporter assay. <b><i>Results:</i></b> Downregulation of miR-31-5p and upregulation of SOX4 were observed in both OA patients and OA chondrocytes. Mechanistic experiments revealed that miR-31-5p negatively modulated SOX4 expression by directly targeting its 3′- untranslated region. Moreover, overexpression of miR-31-5p suppressed the activation of mTORC1 in an ERK-dependent manner by inhibiting SOX4. Further functional experiments demonstrated that overexpressing miR-31-5p in OA chondrocytes markedly promoted its proliferation and autophagy while inhibiting apoptosis. However, these effects were abolished by overexpression of SOX4 or treatment with 3BDO, an mTOR activator. <b><i>Conclusion:</i></b> These results demonstrated that miR-31-5p enhanced survival and autophagy of OA chondrocytes through inactivation of mTORC1 via directly targeting SOX4, suggesting that miR-31-5p may play a protective role in OA progression.