A Pleomorphic Puzzle: Heterogeneous Pulmonary Vascular Occlusions in Patients with COVID-19.

Vascular occlusions in patients with coronavirus diseases 2019 (COVID-19) have been frequently reported in severe outcomes mainly due to a dysregulation of neutrophils mediating neutrophil extracellular trap (NET) formation. Lung specimens from patients with COVID-19 have previously shown a dynamic morphology, categorized into three types of pleomorphic occurrence based on histological findings in this study. These vascular occlusions in lung specimens were also detected using native endogenous fluorescence or NEF in a label-free method. The three types of vascular occlusions exhibit morphology of DNA rich neutrophil elastase (NE) poor (type I), NE rich DNA poor (type II), and DNA and NE rich (type III) cohort of eleven patients with six males and five females. Age and gender have been presented in this study as influencing variables linking the occurrence of several occlusions with pleomorphic contents within a patient specimen and amongst them. This study reports the categorization of pleomorphic occlusions in patients with COVID-19 and the detection of these occlusions in a label-free method utilizing NEF.

Helicobacter Infection and Gastric Adenoma.

BACKGROUND: We aimed to provide insight into the actual frequencies of gastric adenoma types and their association with gastritis status and associated mucosal changes with a focus on Helicobacter infection and the operative link on gastritis assessment (OLGA)/operative link on gastric intestinal metaplasia assessment (OLGIM) staging. METHODS: From the archive of the Institute of Pathology in Bayreuth, we collected a consecutive series of 1058 gastric adenomas diagnosed between 1987 and 2017. Clinicopathological parameters retrieved from diagnostic reports included adenoma type and localization, associated mucosal changes in antrum and corpus (i.e., type of gastritis, the extent of intestinal metaplasia and atrophy), gender, date of birth, and date of diagnosis. RESULTS: Intestinal-type adenoma was the most frequent adenoma (89.1%), followed by foveolar-type adenoma (4.3%), pyloric gland adenoma (3.4%), adenomas associated with hereditary tumor syndromes (2.8%), and oxyntic gland adenoma (0.4%). Adenomas were found in the background of Helicobacter pylori (H. pylori) gastritis in 23.9%, Ex-H. pylori gastritis in 36.0%, autoimmune gastritis in 24.8%, chemical reactive gastritis in 7.4%, and others in 0.1%. More than 70% of patients with gastric adenomas had low-risk stages in OLGA and OLGIM. CONCLUSIONS: We found a higher frequency of foveolar-type adenoma than anticipated from the literature. It needs to be questioned whether OLGA/OLGIM staging can be applied to all patients.

Vascular occlusion by neutrophil extracellular traps in COVID-19.

BACKGROUND: Coronavirus induced disease 2019 (COVID-19) can be complicated by severe organ damage leading to dysfunction of the lungs and other organs. The processes that trigger organ damage in COVID-19 are incompletely understood. METHODS: Samples were donated from hospitalized patients. Sera, plasma, and autopsy-derived tissue sections were examined employing flow cytometry, enzyme-linked immunosorbent assays, and immunohistochemistry. PATIENT FINDINGS: Here, we show that severe COVID-19 is characterized by a highly pronounced formation of neutrophil extracellular traps (NETs) inside the micro-vessels. Intravascular aggregation of NETs leads to rapid occlusion of the affected vessels, disturbed microcirculation, and organ damage. In severe COVID-19, neutrophil granulocytes are strongly activated and adopt a so-called low-density phenotype, prone to spontaneously form NETs. In accordance, markers indicating NET turnover are consistently increased in COVID-19 and linked to disease severity. Histopathology of the lungs and other organs from COVID-19 patients showed congestions of numerous micro-vessels by aggregated NETs associated with endothelial damage. INTERPRETATION: These data suggest that organ dysfunction in severe COVID-19 is associated with excessive NET formation and vascular damage. FUNDING: Deutsche Forschungsgemeinschaft (DFG), EU, Volkswagen-Stiftung.

Dual-Acting Cholinesterase-Human Cannabinoid Receptor 2 Ligands Show Pronounced Neuroprotection in Vitro and Overadditive and Disease-Modifying Neuroprotective Effects in Vivo.

We have designed and synthesized a series of 14 hybrid molecules out of the cholinesterase (ChE) inhibitor tacrine and a benzimidazole-based human cannabinoid receptor subtype 2 (hCB2R) agonist and investigated them in vitro and in vivo. The compounds are potent ChE inhibitors, and for the most promising hybrids, the mechanism of human acetylcholinesterase (hAChE) inhibition as well as their ability to interfere with AChE-induced aggregation of ß-amyloid (Aß), and Aß self-aggregation was assessed. All hybrids were evaluated for affinity and selectivity for hCB1R and hCB2R. To ensure that the hybrids retained their agonist character, the expression of cAMP-regulated genes was quantified, and potency and efficacy were determined. Additionally, the effects of the hybrids on microglia activation and neuroprotection on HT-22 cells were investigated. The most promising in vitro hybrids showed pronounced neuroprotection in an Alzheimer's mouse model at low dosage (0.1 mg/kg, i.p.), lacking hepatotoxicity even at high dose (3 mg/kg, i.p.).

Expression profiles of cancer stem cell markers: CD133, CD44, Musashi-1 and EpCAM in the cardiac mucosa-Barrett's esophagus-early esophageal adenocarcinoma-advanced esophageal adenocarcinoma sequence.

INTRODUCTION: Barrett's esophagus (BE), which develops as a result of gastroesophageal reflux disease, is a preneoplastic condition for esophageal adenocarcinoma (EAC). A new hypothesis suggests that cancer is a disease of stem cells, however, their expression and pathways in BE - EAC sequence are not fully elucidated yet. AIMS: We used a panel of putative cancer stem cells markers to identify stem cells in consecutive steps of BE-related cancer progression. METHODS: Immunohistochemistry was performed on formalin-fixed, paraffin-embedded blocks from 58 patients with normal cardiac mucosa (n=5), BE (n=14), early EAC (pT1) from mucosal resection (n=17) and advanced EAC (pT1-T4) from postoperative specimens (n=22). Expression of the CD133, CD44, Musashi-1 and EpCAM was analyzed using respective monoclonal antibodies. RESULTS: All markers showed a heterogeneous expression pattern, mainly at the base of the crypts of Barrett's epithelium and EAC, with positive stromal cells in metaplastic and dysplastic lesions. Immuno-expression of EpCAM, CD44 and CD133 in cardiac mucosa was significantly lower (mean immunoreactivity score (IRS)=1.2; 0.0; 0.4; respectively) compared to their expression in Barrett's metaplasia (mean IRS=4.3; 0.14; 0.7; respectively), in early adenocarcinoma (mean IRS=4.4; 0.29; 1.3; respectively) and in advanced adenocarcinoma (mean IRS=6.6; 0.7; 2.7; respectively) (p<0.05). On the contrary, Musashi-1 expression was higher in BE and early ADC compared to GM and advanced ADC (NS). CONCLUSION: Our results suggest that the stem cells could be present in premalignant lesions. EpCAM, CD44 and CD133 expression could be candidate markers for BE progression, whereas Musashi-1 may be a marker of the small intestinal features of Barrett's mucosa.

Fibroblasts produce brain-derived neurotrophic factor and induce mesenchymal transition of oral tumor cells.

Fibroblasts (Fibs) contribution to neoplastic progression, tumor growth, angiogenesis, and metastasis has been recently reported by several research groups. In this study it was investigated if fibroblasts are the source of brain-derived neurotrophic factor (BDNF), which plays a crucial role in the progression of oral squamous cell carcinoma. In a novel in vitro system oral Fibs were cultured with SCC-25 lingual squamous cell carcinoma cells for 7days. Factors related with this interaction were investigated by quantitative PCR and western blot. In the co-culture, fibroblasts were converted to carcinoma-associated fibroblasts (CAFs), which in return initiated epithelial-mesenchymal transition (EMT) of SCC-25 cells. The induced CAFs produced increased levels of BDNF, which interacted with the increased-expressed neurothrophin receptor B (TrkB) on EMT-converted SCC-25 cells. Possible regulatory factors of BDNF expression (tumor necrosis factor-α and interleukin-1-ß) were detected both in CAFs and EMT-tumor cells. In CAFs: IL-1ß-, in SCC-25 cells TNF-α-gene-expression was significantly increased in co-culture conditions. Activated fibroblasts (CAFs) and mesenchymal transitioned tumor cells might use the BDNF-TrkB axis and its regulation to harmonize their interaction in the process of tumor progression.

The cochlea in fetuses with neural tube defects.

In this study different malformations of the cochlea could be demonstrated. Nevertheless, we could not delineate a distinct malformation of the inner ear, that can be linked to a neural tube defect. Neural tube defects are a frequent and heterogeneous group of malformations, ranging from the survivable spina bifida to fatal anencephaly. In multiple animal models an involvement of the vestibulocochlear system has been demonstrated. In this article human fetal temporal bones of neural tube defects were analysed in a multimodular work-up. The morphologic study was performed with light microscopy, transmission electron microscopy and synchrotron radiation-based microcomputed tomography. Immunohistochemistry for different neuronal markers such as peripherin, beta-III-tubulin and vimentin helped to evaluate ontogenetic tissue development. Eight fetal temporal bones with neural tube defects and five control temporal bones were included into the morphologic study. The morphologic results of the neural tube defect temporal bones showed six regularly developed cochleas and two with only a single cochlear turn. Three of the neural tube defect temporal bones were further examined with immunohistochemical analysis. No differences in the staining pattern for peripherin, beta-III-tubulin and vimentin were detected.

Epidermal growth factor receptor expression in human fetal cochlea with Turner syndrome.

HYPOTHESIS: Growth hormones have beneficial effects on increasing height in adults with Turner syndrome (TS) and may also affect auditory function. BACKGROUND: Turner syndrome is the most common sex-linked chromosomal abnormality in female conceptions. Epidermal growth factor and its receptor (EGFR) affect differentiation, proliferation, and migration of epithelial cells and function as survival factors. The expression of EGFR is found in the developing and juvenile inner ear of experimental animals but is absent in adults. METHODS: To determine whether EGFR plays a role in TS, its expression was analyzed in the cochlea of healthy fetus and fetus with TS and in healthy adults. RESULTS: In healthy fetuses, EGFR protein expression was localized to the inner and outer hair cells and the Reissner membrane. The fetuses with TS on the 13th gestational week (GW) showed a similar pattern of immunoreactivity as the normal 16th and 20th GW cochlea. By the 23rd GW, EGFR immunoreactivity was not detectable in the TS hair cells or the Reissner membrane, and less intensive staining was found in the surrounding fibrocytes of the spiral ganglion. CONCLUSION: This is the first demonstration of EGFR immunoreactivity in the human cochlea and illustrates how EGFR expression is altered during development in TS. These findings indicate the importance of growth hormone receptors for inner ear development in humans.

Kidney transplantation in patients suffering from hereditary complete complement C4 deficiency.

Hereditary complete C4 deficiency (C4def) is a very rare condition that predisposes to immune complex disease and end-stage renal failure. Whether such patients should undergo renal transplantation is debated. The clinical outcome of five transplantations in three C4def patients is described. The first patient lost one allograft after 6 years because of chronic allograft rejection. Back on dialysis, he suffered from meningitis caused by Neisseria menigitidis and Aspergillus. One year after a second transplantation under alemtuzumab induction, he developed fulminant Kaposi's sarcoma and died. His sister is now 6 years post-transplantation without complications. The third patient lost his first graft after 3 years because of chronic allograft nephropathy and recurrence of glomerulonephritis. He has now been living with a second graft for over 9 years. He suffered from pneumonia, a generalized varicella infection and Hemophilis parainfluenzae bronchitis. Patients with complete C4def are at increased risk for infection after kidney transplantation. Under certain precautions and with judicious use of immunosuppression, good long-term results are achievable.