Search

Abstract Native mucus is heterogeneous, displays high inter-individual variation and is prone to changes during harvesting and storage. To overcome the lack of reproducibility and availability of native mucus, commercially available purified mucins, porcine gastric mucin (PGM) and mucin from bovine submaxillary gland (BSM), have been widely used. However, the question is to which extent the choice of mucin matters in studies of their interaction with polymers as their composition, structure and hence physicochemical properties differ. Accordingly, the interactions between PGM or BSM with two widely used polymers in drug delivery, polyethylene oxide and chitosan, was studied with orthogonal methods: turbidity, dynamic light scattering, and quartz crystal microbalance with dissipation monitoring. Polymer binding and adsorption to the two commercially available and purified mucins, PGM and BSM, is different depending on the mucin type. PEO, known to interact weakly with mucin, only displayed limited interaction with both mucins as confirmed by all employed methods. In contrast, chitosan was able to bind to both PGM and BSM. Interestingly, the results suggest that chitosan interacts with BSM to a greater extent than with PGM indicating that the choice of mucin, PGM or BSM, can affect the outcome of studies of mucin interactions with polymers.

Abstract Lepidopteran silk is a complex mixture of proteins, consisting mainly of fibroins and sericins. Sericins are a small family of highly divergent proteins that serve as adhesives and coatings for silk fibers. So far, five genes encoding sericin proteins have been identified in Bombyx mori. Having previously identified sericin protein 150 (SP150) as a major sericin-like protein in the cocoons of the pyralid moths Galleria mellonella and Ephestia kuehniella, we describe the identification of its homolog in B. mori. Our refined gene model shows that it consists of four exons and a long open reading frame with a conserved motif, CXCXCX, at the C-terminus, reminiscent of the structure observed in a class of mucin proteins. Notably, despite a similar expression pattern, both mRNA and protein levels of B. mori SP150 were significantly lower than those of its pyralid counterpart. We also discuss the synteny of homologous genes on corresponding chromosomes in different moth species and the possible phylogenetic relationships between SP150 and certain mucin-like proteins. Our results improve our understanding of silk structure and the evolutionary relationships between adhesion proteins in the silk of different lepidopteran species.

Gastroesophageal reflux disease （GERD） is a common recurrent disease and the treatment of GERD is challenging. Chronic heartburn and/or reflux symptoms seriously affect the quality of daily life of patients. Studies have shown that GERD is closely associated with the impairment of anti-reflux barrier of the esophagus，of which mucin （MUC） is the main component. The role of MUC in the pathogenesis of GERD and influencing factors were reviewed in this article.

Mucinous Appendiceal Neoplasms (MANs) are rare tumours where more than 50% of the tumour volume is composed of extracellular mucin. Low-grade Appendiceal Mucinous Neoplasm (LAMN) is a rare condition with symptoms that vary depending on clinical manifestations. It can manifest as an unruptured mucin-filled appendix, transmural invasion of the primary tumour, or present with peritoneal metastases post-rupture. The prognosis of LAMN depends on the presence or absence of neoplastic epithelium outside the appendix. Here, the authors describe a case of 35-year-old female who visited the OPD of Emergency Medicine with only complain of pain in abdomen for three days. She exhibited right iliac fossa tenderness with no guarding during the abdominal examination. She underwent an open appendectomy and was diagnosed with LAMN upon histopathological examination. She was advised to follow up after six months post-discharge to monitor for any metastatic spread. Due to its malignant potential, mucinous lesions of the appendix are uncommon yet significant entities. They are more prevalent in women and can range from mucinous adenocarcinomas to straightforward retention cysts. This case illustrates the need for extreme caution when dealing with appendiceal tumours and the importance of selecting the appropriate course of action, be it surgical or medical.

Appendicular adenocarcinoma is a rare tumour, and the mucin variety is common. It is usually presented with symptoms such as abdominal pain, abdominal tenderness, nausea, vomiting, change in bowel habits, and unexplained weight loss. These symptoms can resemble those of other clinical conditions, making the diagnosis of appendicular adenocarcinoma challenging. Screening modalities such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT) imaging, Contrast-Enhanced Computed Tomography (CECT), blood tests, and histopathological analysis can help confirm the diagnosis. This case is reported to highlight the unusual presentation and diagnostic difficulties associated with appendiceal adenocarcinoma. A 48 years old female patient presented with complaints of dull, continuous abdominal pain for the past six months, along with an abdominal lump and distension, without any other associated symptoms. Laboratory investigations for Cancer Antigen 125 (CA 125), β-Human Chorionic Gonadotropin (HCG), and α-fetoprotein were found to be within normal limits. Further, CECT imaging was suggestive of mucin-secreting adenocarcinoma of ovarian origin. The final diagnosis was confirmed by histopathological analysis as mucinsecreting adenocarcinoma of the appendix with pseudomyxoma peritonei and was managed through cytoreduction surgery.

Key Clinical Message Upper respiratory tract villous adenoma (VA) with muconephrosis is rare and should be included in the differential diagnosis when pelvic dilatation with a solid component is detected. VA may transform into malignant mucinous adenocarcinoma, which should be suspected if contrast enhancement on computed tomography (CT)/magnetic resonance imaging (MRI) and restricted diffusion on MRI are observed.

Background Changes in protein glycosylation have been reported in various diseases, including cancer; however, the consequences of altered glycosylation in meningiomas remains undefined. We established two benign meningioma cell lines—SUT-MG12 and SUT-MG14, WHO grade I—and demonstrated the glycan and glycosyltransferase profiles of the mucin-type O-linked glycosylation in the primary benign meningioma cells compared with two malignant meningioma cell lines—HKBMM and IOMM-Lee, WHO grade III. Changes in O-linked glycosylation profiles in malignant meningiomas were proposed. Methods Primary culture technique, morphological analysis, and immunocytochemistry were used to establish and characterize two benign meningioma cell lines. The glycan profiles of the primary benign and malignant meningiomas cell lines were then analyzed using lectin cytochemistry. The gene expression of O-linked glycosyltransferases, mucins, sialyltransferases, and fucosyltransferases were analyzed in benign and malignant meningioma using the GEO database (GEO series GSE16581) and quantitative-PCR (qPCR). Results Lectin cytochemistry revealed that the terminal galactose (Gal) and N-acetyl galactosamine (GalNAc) were highly expressed in primary benign meningioma cells (WHO grade I) compared to malignant meningioma cell lines (WHO grade III). The expression profile of mucin types O-glycosyltransferases in meningiomas were observed through the GEO database and gene expression experiment in meningioma cell lines. In the GEO database, C1GALT1-specific chaperone (COSMC) and mucin 1 (MUC1) were significantly increased in malignant meningiomas (Grade II and III) compared with benign meningiomas (Grade I). Meanwhile, in the cell lines, Core 2 β1,6-N-acetylglucosaminyltransferase-2 (C2GNT2) was highly expressed in malignant meningiomas. We then investigated the complex mucin-type O-glycans structures by determination of sialyltransferases and fucosyltransferases. We found ST3 β-galactoside α-2,3-sialyltransferase 4 (ST3GAL4) was significantly decreased in the GEO database, while ST3GAL1, ST3GAL3, α1,3 fucosyltransferases 1 and 8 (FUT1 and FUT8) were highly expressed in malignant meningioma cell lines—(HKBMM)—compared to primary benign meningioma cells—(SUT-MG12 and SUT-MG14). Conclusion Our findings are the first to demonstrate the potential glycosylation changes in the O-linked glycans of malignant meningiomas compared with benign meningiomas, which may play an essential role in the progression, tumorigenesis, and malignancy of meningiomas.

Low-grade Appendiceal Mucinous Neoplasm (LAMN) is a rare malignant neoplasm seen in less than 0.3% of appendectomy specimens. Patients with LAMN can present with abdominal pain, mimicking appendicitis clinically. In later stages, it can rupture, leading to Pseudomyxoma peritonei (PMP). Therefore, a high clinical suspicion is needed for correct diagnosis and management. The prognosis of LAMN depends on the presence or absence of mucin/neoplastic epithelium outside the appendix. For LAMN confined to the appendix, appendectomy alone is sufficient for management, with conservative follow-up. For LAMN with extruded acellular mucin localised to the appendiceal serosa, management involves appendectomy and PMP surveillance. For all mucinous lesions of the appendix, it is essential to submit the entire appendix for histopathologic examination, thoroughly evaluating the presence of mucin/neoplastic epithelium involving the serosa/extra appendiceal tissue for accurate staging and to predict the risk of recurrence and determine further management. Here four cases of LAMN due to their rarity and clinical importance is presented. This study of four cases emphasises that the clinical diagnosis of this rare malignancy is difficult, and radiological investigations were not available as these patients presented with clinical features mimicking appendicitis. Emergency appendectomy was performed in all cases. LAMN should be considered as a differential diagnosis because if not diagnosed and treated in the early stages, it can lead to dreaded complications like PMP. The histopathological examination of all four cases of LAMN showed dissecting acellular mucin in various stages of progression in the appendicular wall, but none involving the serosa. This highlights the importance of timely surgical intervention and histopathological examination for an exact diagnosis and staging of LAMN for further follow-up or treatment.

Abstract Objective Cystic fibrosis (CF) is a genetic condition that causes abnormal mucus secretions in affected organs. MUC5AC and MUC5B are gel-forming mucins and frequent targets for investigations in CF tissues. Our objective was to qualify MUC5AC and MUC5B immunohistochemical techniques to provide a useful tool to identify, localize and interpret mucin expression in ferret tissues. Results MUC5AC and MUC5B mucins were detected most commonly in large airways and least in small airways, consistent with reported goblet cell density in airway surface epithelia. We evaluated whether staining method affected the detection of goblet cell mucins in serial sections of bronchial surface epithelia. Significant differences between stains were not observed suggesting common co-expression MUC5AC and MUC5B proteins in goblet cells of airway surface epithelia. Gallbladder and stomach tissues are reported to have differential mucin enrichment, so we tested these tissues in wildtype ferrets. Stomach tissues were enriched in MUC5AC and gallbladder tissues enriched in MUC5B, mucin enrichment similar to human tissues. Mucin immunostaining techniques were further qualified for specificity using lung tissue from recently generated MUC5AC −/− and MUC5B −/− ferrets. Qualified techniques for MUC5AC and MUC5B immunohistochemistry will be useful tools for mucin tissue studies in CF and other ferret models.

Key Clinical Message In reticular erythematous mucinosis, (1) the presence of dotted vessels and (2) uniform, structureless, yellowish‐white spots, and patches on dermoscopy correspond to histopathological findings of (1) vessels at the tips of the dermal papillae and (2) thickening and rupture of the collagen and fiber bundles with mucin deposition, respectively. Abstract Reticular erythematous mucinosis is a rare form of skin mucinosis that primarily affects middle‐aged women, typically appearing as papules and plaques in the upper chest or midline of the back. Here, we report the case of a 75‐year‐old woman with skin papules and plaques left untreated for 8 years. A gross skin examination was followed by histopathological and dermoscopic examinations. The main dermoscopic findings were (1) dotted vessels and (2) uniform structureless yellowish‐white spots and patches. The corresponding histopathological findings were (1) vessels at the tips of the dermal papillae and (2) thickening and rupturing of the collagen and fiber bundles with mucin deposition, respectively. Laboratory investigations revealed normal results, ruling out various autoimmune disorders. REM was diagnosed based on these findings. The study presents relevant evidence‐based findings in dermatology and cutaneous pathology as it is the first description of REM using dermoscopy. Dermoscopic diagnosis without other unnecessary tests would benefit both the clinician and the patient.

Solithromycin is a novel fluoroketolide antibiotic belonging to the class of macrolide antibiotics. Activation of the interleukin (IL)-13 receptor leads to STAT6 activation and subsequent induction of SAM pointed domain containing ETS transcription factor (SPDEF), chloride channel accessory 1 (CLCA1), and anoctamin-1 (ANO1), all of which are associated with the induction of MUC5AC. We examined the effects of solithromycin on mucin production led by IL-13 signaling. Normal human bronchial epithelial cells were grown at the air-liquid interface with IL-13 with/without solithromycin for 14 days. Histochemical analysis was performed using hematoxylin and eosin staining and MUC5AC immunostaining. MUC5AC, SPDEF, CLCA1, and ANO1 mRNA expressions were examined using real-time polymerase chain reaction. Western blot analysis was performed to assess CLCA1 and ANO1 proteins, and phosphorylation of STAT6 and ERK. Solithromycin attenuated IL-13 induction of goblet cell hyperplasia and MUC5AC, CLCA1 and ANO1 mRNA and protein expression induced by IL-13, but had no effect on the phosphorylation of STAT6 and ERK. Our results indicate that solithromycin could attenuate goblet cell hyperplasia and MUC5AC induced by IL-13 through inhibition of CLCA1 and ANO1 mRNA and protein expression. However, much more information is required to clarify the molecular mechanisms underlying the inhibition of CLCA1 and ANO1 by solithromycin.

Pseudomyxoma peritonei (PMP) is a rare and uncommon condition, characterized by the presence of mucinous ascites in the abdominal cavity. The most common cause of PMP is mucinous adenocarcinoma of the appendix, followed by neoplasms of the ovary, endocervix, fallopian tube, alimentary organs, urachus, urinary bladder, lung, mucinous cyst of the spleen, and breast. Herein, we report a case of a 64-year-old postmenopausal woman (gravida 2, para 2) who presented at the department of gynecology with a short history of nausea and abdominal distention. Abdominal and vaginal ultrasonography showed a large amount of free fluid in the pelvis with hyperechoic echogenicity and right pelvic tumor with mixed echogenicity. Computed tomography demonstrated the presence of a heterogeneous, hypodense mass, without contrast enhancement, located on the right side of the pelvis, near the right ovary. Laparotomy was performed. Revision of the abdominal cavity revealed a large amount of yellow gelatinous mucinous ascites – approximately 1.5 l. A tumor (6 x 7 cm in diameter), arising from the appendix and located in the pouch of Douglas near the right ovary, was observed. Histopathology examination revealed poorly differentiated mucinous appendiceal adenocarcinoma, comprising up to 50% signet ring cells. Gastrointestinal tumors such as appendiceal neoplasms combined with PMP may mimic ovarian carcinomas. Computed tomography, abdominal/vaginal ultrasonography and tumor marker levels (carcino-embryonic antigen, carbohydrate antigen 19.9, carbohydrate antigen Ca-125) may establish the diagnosis. A differential diagnosis with appendiceal tumors should be considered for patients with right pelvic masses.

Pseudomyxoma peritonei (PMP) is a rare malignant growth characterized by the production of mucin and the potential for peritoneal relapse. This study aimed to investigate the immunohistochemical and biological characteristics of mucin in patients with cellular and acellular PMP. We prospectively analyzed mucin specimens obtained from our patient cohort and described the composition and type of mucin present in each sample. A metagenomic analysis of the samples was performed to investigate the bacterial composition of the PMP microbiome. Secreted mucins 2 and 5AC and membrane-associated mucin-1 were the primary components of mucin in both cellular and acellular tumor specimens. The metagenomic study revealed a predominance of the phylum Proteobacteria and the genus Pseudomonas. Notably, Pseudomonas plecoglossicida, a species not previously reported in the human microbiome, was found to be the most abundant organism in the mucin of pseudomyxoma peritonei. Our findings suggest that the presence of MUC-2 and mucin colonization by Pseudomonas are characteristic features of both cellular and acellular disease. These results may have significant implications for the diagnosis and treatment of this rare entity.

Accurately identifying metastatic disease is critical to directing the appropriate treatment in pancreatic cancer. Mucin 5AC is overexpressed in pancreatic cancer but absent in normal pancreas tissue. The present proof-of-concept study demonstrates the efficacy of an anti-mucin 5AC antibody conjugated to an IR800 dye (MUC5AC-IR800) to preferentially label a liver metastasis of pancreatic cancer (Panc Met) in a unique patient-derived orthotopic xenograft (PDOX) model. In orthotopic models, the mean tumor to background ratio was 1.787 (SD ± 0.336), and immunohistochemistry confirmed the expression of MUC5AC within tumor cells. MUC5AC-IR800 provides distinct visualization of pancreatic cancer liver metastasis in a PDOX mouse model, demonstrating its potential utility in staging laparoscopy and fluorescence-guided surgery.

Hemostasis in the arterial circulation is mediated by binding of the A1 domain of the ultralong protein von Willebrand factor (VWF) to GPIbα on platelets to form a platelet plug. A1 is activated by tensile force on VWF concatemers imparted by hydrodynamic drag force. The A1 core is protected from force-induced unfolding by a long-range disulfide that links cysteines near its N- and C-termini. The O-glycosylated linkers between A1 and its neighboring domains, which transmit tensile force to A1, are reported to regulate A1 activation for binding to GPIb, but the mechanism is controversial and incompletely defined. Here, we study how these linkers, and their polypeptide and O-glycan moieties, regulate A1 affinity by measuring affinity, kinetics, thermodynamics, hydrogen deuterium exchange (HDX), and unfolding by temperature and urea. The N-linker lowers A1 affinity 40-fold with a stronger contribution from its O-glycan than polypeptide moiety. The N-linker also decreases HDX in specific regions of A1 and increases thermal stability and the energy gap between its native state and an intermediate state, which is observed in urea-induced unfolding. The C-linker also decreases affinity of A1 for GPIbα, but in contrast to the N-linker, has no significant effect on HDX or A1 stability. Among different models for A1 activation, our data are consistent with the model that the intermediate state has high affinity for GPIbα, which is induced by tensile force physiologically and regulated allosterically by the N-linker.

Background: Chronic rhinosinusitis (CRS) is a heterogeneous disease. The pathogenesis of chronic sinusitis is still unclear; however, the nasal cavity and paranasal sinuses are commonly affected by type 2 inflammation, which is caused by Th2 cytokines such as interleukin (IL)-5, IL-4, and IL-13. Previous studies have shown that pendrin promotes local infiltration of neutrophils through the production of human neutrophil elastase (HNE), which is essential for the secretion of mucin 5AC (MUC5AC) in chronic inflammatory diseases of the lower respiratory tract. This study investigated pendrin expression and its relationship to mucin in type 2 inflammation. Methods: A total of 40 patients (10 CRS patients with nasal polyps,10 CRS patients without nasal polyps, and 20 nasal septum deviation patients) were included in this study and were divided into the CRS group and the NC group. A normal nasal mucosa tissue culture model was established in vitro. IL-13 was used to stimulate primary cultures of human nasal epithelial cells (HNECs). Western blot (WB), enzyme-linked immunosorbent assay (ELISA), and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of pendrin, MUC5AC, and MUC5B. After transfecting HNECs with siRNA pendrin or negative control (NC), EGF receptor (EGFR), HNE, MUC5AC, and MUC5B expression were analyzed using qRT-PCR, WB, or ELISA in terms of their relationships with pendrin. Pendrin expression in the tissue was also analyzed. Results: After IL-13 stimulation, pendrin, MUC5AC, and MUC5B expression levels were upregulated; the optimal concentration of IL-13 was 50 ng/mL. The expression levels of HNE, EGFR, MUC5AC, and MUC5B were downregulated after transfection with siRNA pendrin-1650. Pendrin expression in the NC group was lower than in the CRS group. Conclusion: IL-13 is implicated in the inflammation of nasal mucosa, and pendrin is closely related to the excessive secretion of mucin. The expression of mucin is downregulated after transfection with siRNA pendrin. There is a positive relationship between pendrin and EFGR/HNE. Moreover, pendrin plays an important role in type 2 inflammation.

It is critical to distinguish the rare neoplasm of mucin-producing urothelial-type adenocarcinoma of the prostate (MPUAP) from either prostate origin or metastatic adenocarcinoma. This is mainly because they have different tumor staging, clinical behavior and treatment plans. In the current study, we try to fulfill the lack of knowledge in this field. There were totally 24 MPUAP cases including previous reported 23 cases and adding one new MPUAP case in the current study. We performed IHC and 78 genes panel analysis in two cases of ours. Most of the cases had urinary obstruction symptoms and normal PSA level. Pathological features showed dissection of the stroma by mucin pools and glands lined by pseudostratified columnar mucinous epithelium with varying degrees of cytological atypia. The IHC results showed positive for CK20, CEA, CDX-2, β-catenin, p53, MUC2 and MUC5AC, negative for PSA, AMACR, GATA3, MUC6, AR and NKX3.1 and variable expression for HMWCK and CK7. Genetic analysis revealed concurrent mutations of FAT1 (c.10001 T>C) and HNF1A in both cases. The similar morphology features of MPUAP and colorectal adenocarcinoma were seen. Membranous staining pattern of β-catenin and genetic mutation of FAT1 and HNF1A are two distinct features in MPUAP.

Abstract Background Melatonin (5-methoxy-N-acetyltryptamine), a hormone produced in the pineal gland, has a variety of biological functions as an antioxidant, but a functional role of melatonin in the regulation of intestinal mucin (Muc) production during bacterial infection has yet to be described in detail. In this study, we investigate the effects of melatonin during Muc2 repression elicited by the Gram-negative bacterium V. vulnificus. Methods Mucus-secreting human HT29-MTX cells were used to study the functional role of melatonin during Muc2 depletion induced by the recombinant protein (r) VvpM produced by V. vulnificus. The regulatory effects of melatonin coupling with melatonin receptor 2 (MT2) on the production of reactive oxygen species (ROS), the activation of PKCδ and ERK, and the hypermethylation of the Muc2 promoter as induced by rVvpM were examined. Experimental mouse models of V. vulnificus infection were used to study the role of melatonin and how it neutralizes the bacterial toxin activity related to Muc2 repression. Results Recombinant protein (r) VvpM significantly reduced the level of Muc2 in HT29-MTX cells. The repression of Muc2 induced by rVvpM was significantly restored upon a treatment with melatonin (1 μM), which had been inhibited by the knockdown of MT2 coupling with Gαq and the NADPH oxidase subunit p47 phox. Melatonin inhibited the ROS-mediated phosphorylation of PKCδ and ERK responsible for region-specific hypermethylation in the Muc2 promoter in rVvpM-treated HT29-MTX cells. In the mouse models of V. vulnificus infection, treatment with melatonin maintained the level of Muc2 expression in the intestine. In addition, the mutation of the VvpM gene from V. vulnificus exhibited an effect similar to that of melatonin. Conclusions These results demonstrate that melatonin acting on MT2 inhibits the hypermethylation of the Muc2 promoter to restore the level of Muc2 production in intestinal epithelial cells infected with V. vulnificus.

Abstract Objective Mucin is an important parameter for detection and assessment in studies of airway disease including asthma and cystic fibrosis. Histochemical techniques are often used to evaluate mucin in tissues sections. Periodic acid Schiff (PAS) is a common technique to detect neutral mucins in tissue, but this technique also detects other tissue components including cellular glycogen. We tested whether depletion of glycogen, a common cellular constituent, could impact the detection of mucin in the surface epithelium of the trachea. Results Normal tissues stained by PAS had significantly more staining than serial sections of glycogen-depleted tissue with PAS staining (i.e. dPAS technique) based on both quantitative analysis and semiquantitative scores. Most of the excess stain by the PAS technique was detected in ciliated cells adjacent to goblet cells. We also compared normal tissues using the Alcian blue technique, which does not have reported glycogen staining, with the dPAS technique. These groups had similar amounts of staining consistent with a high degree of mucin specificity. Our results suggest that when using PAS techniques to stain airways, the dPAS approach is preferred as it enhances the specificity for airway mucin.

Background: There is an increase in the incidence of the prostate cancer by 1% yearly which has been recorded in the last three years. Early diagnosis of prostate cancer is important and differentiation between normal and malignant lesions of prostate has been a diagnostic dilemma. There is unavailability of modern techniques in rural areas as well as in developing countries. Aims and Objectives: To evaluate the usefulness of mucin stains in differentiating normal and malignant lesions of prostate. Material and Methods: The study was done on 33 specimens of normal (n=11) and malignant (n=22) prostates which were collected from postmortem and surgically resected specimens in Krishna Institute of Medical Sciences and Krishna Hospital Medical Research Central. Normal prostate specimens were used as controls with carcinoma of prostate as test. The type of study was case control study. Routine Hematoxylin / Eosin and special stains as PAS, PASDiastase, PAS-Phenyl Hydrazine, Alcian Blue pH-2.5 and 1, Aldehyde Fuchsin, combined AB-PAS and AFAB were performed. Results: Results were tabulated according to colour intensity into different grades ranging from -ve to +++. Neutral mucins were observed in normal prostate and in prostate carcinoma acid mucins were seen predominantly present. Conclusion: Mucin histochemistry may provide a valuable and cost effective tool for the diagnostic histopathology of prostate lesions.

Background: Idiopathic pulmonary fibrosis (IPF) is a complex lung disease, characterized by progressive lung scarring. Severe COVID-19 is associated with substantial pneumonitis and has a number of shared major risk factors with IPF. This study aimed to determine the genetic correlation between IPF and severe COVID-19 and assess a potential causal role of genetically increased risk of IPF on COVID-19 severity. Methods: The genetic correlation between IPF and COVID-19 severity was estimated with linkage disequilibrium (LD) score regression. We performed a Mendelian randomization (MR) study for IPF causality in COVID-19. Genetic variants associated with IPF susceptibility (P

The mucin (MUC) family is a group of highly glycosylated macromolecules that are abundantly expressed in mammalian epithelial cells. MUC proteins contribute to the formation of the mucus barrier and thus have protective functions against infection. Interestingly, some MUC proteins are aberrantly expressed in cancer cells and are involved in cancer development and progression, including cell growth, proliferation, the inhibition of apoptosis, chemoresistance, metabolic reprogramming, and immune evasion. With their unique biological and structural features, MUC proteins have been considered promising therapeutic targets and also biomarkers for human cancer. In this review, we discuss the biological roles of the transmembrane mucins MUC1 and MUC16 in the context of hallmarks of cancer and current efforts to develop MUC1- and MUC16-targeted therapies.

Mucins are a family of glycosylated proteins which are the primary constituents of mucus and play a dynamic role in the regulation of the protective mucosal barriers throughout the human body. Ulcerative colitis (UC) is an Inflammatory Bowel Disease (IBD) characterised by continuous inflammation of the inner layer of the large intestine, and in this systematic review we analyse currently available data to determine whether alterations exist in mucin activity in the colonic mucosa of UC patients. Database searches were conducted to identify studies published between 1990 and 2020 that assess the role of mucins in cohorts of UC patients, where biopsy specimens were resected for analysis and control groups were included for comparison. 5497 articles were initially identified and of these 14 studies were systematically selected for analysis, a further 2 articles were identified through citation chaining. Therefore, 16 studies were critically reviewed. 13 of these studies assessed the role of MUC2 in UC and the majority of articles indicated that alterations in MUC2 structure or synthesis had an impact on the colonic mucosa, although conflicting results were presented regarding MUC2 expression. This review highlights the importance of further research to enhance our understanding of mucin regulation in UC and summarises data that may inform future studies.

Aim: Chronic gastritis (CG), being one of the most common digestive diseases, is frequently underestimated both by patients and clinicians. However, CG developed as early as in childhood, and often accompanied by Helicobacter pylori contamination of antral mucus, has a persistent recurrent course in adult patients, complicated by mucosal transformations in the form of atrophy, metaplasia and dysplasia. CG can appear as an early stage in the morphogenesis of tumor growth. From this point of view, CG is worth noticing. Materials and Methods: A complex morphological study of antral mucosa in school children with atrophic gastritis has been performed using histochemistry, immunohistochemistry and a morphometric methods. Results: In atrophic gastritis we have revealed the decrease in the number of functionally mature cells responsible for the production of extracellular matrix and basal membrane components, the lack of which in paraepithelial localization results in the change of their special properties. In addition, sulphomucins, non-characteristic of stomach, overlapped on mucosa and in single foveolae have been found in atrophic gastritis. Conclusion: Permanent impairment in the conjugation of cell and tissue components in mucosa accompanied by the change of an epithelial layer synthetic function with the impaired physicochemical properties of gastric mucin results in intestinal metaplasia as early as in childhood. Introduction

Polypous rhinosinusitis is a chronic disease of the nasal mucosa and paranasal sinuses, which is characterized by recurrent growth of nasal polyps. This disease is found in 1-5% of the population. According to the data of 2017, patients with nasal polypous rhinosinusitis account for 13% of all patients treated in our clinic. Polypous rhinosinusitis can be either an independent disease or a manifestation of other diseases. Aim - to present a case from practice, which is interesting due to the fact that two independent diseases were hiding under the mask of polypous rhinosinusitis. Results. Strict administration of the diagnostic algorithm, modern principles of functional surgery of the paranasal sinuses led to the recovery of the patient.

Introduction: Cholelithiasis and asymptomatic gallstones may produce pathological changes like hyperplasia and metaplasia of the gall bladder mucosal epithelium. It has been suggested that metaplastic epithelium is more susceptible to malignant transformation than the normal mucosa and the intestinal metaplasia-dysplasia-carcinoma sequence exists in the gall bladder. So, it is essential to detect metaplastic lesions of gall bladder early and mucin histochemistry study may be useful in this regard. Aim: To find out if mucin histochemistry can be used for early detection of metaplastic lesions of gall bladder as metaplastic epithelium is more prone to malignant transformation. Materials and Methods: A total of 1153 formalin-fixed paraffinembedded surgically resected gallbladder tissue samples were sectioned. All sections were stained with HaematoxylinEosin (HE), Alcian Blue (AB) and Periodic Acid-Schiff (PAS) stain. Results: A total of 1153 cholecystectomy cases were observed. Maximum cases were of chronic cholecystitis with gall stones (841 cases). Metaplasia was found in 201 out of 1153 cases. Mucin histochemistry in metaplastic group showed only PAS positivity in 52 cases (neutral mucin), both PAS and AB positivity in 122 cases (acidic mucin) and only AB positivity in 27 cases (acidic mucin). Conclusion: The gastric and intestinal metaplasia showed positivity more with acidic mucin than neutral mucin. Study of mucin histochemistry in metaplastic cases can lead to early detection and early diagnosis of carcinoma gallbladder.