Epithelial Membrane Research Articles

Validation and shortcomings of the most common mouse model of chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis (CRS) is a highly prevalent airway disease worldwide. Whereas eosinophilic CRS with nasal polyps (eCRSwNP) represents its most severe phenotype, pathogenic mechanisms remain poorly understood despite a wide spectrum of in vitro and in vivo experimental models. A mouse model of experimental ovalbumin (OVA)-induced airway allergy with coadministration of Staphylococcus aureus enterotoxin B (SEB) has been widely used to study eosinophilic eCRSwNP. This study revisits the features of this model and its suitability for studying eCRS. We implemented the most used eCRSwNP mouse model based on OVA+SEB intranasal challenges. Readouts including inflammatory features by (immuno)histology of the sinonasal epithelium (NP formation, eosinophils, epithelial and basement membrane thickness, fibrosis, goblet cells, Charcot-Leyden crystals (CLC)-like, tight junctions) and IgE production by enzyme-linked immunosorbent assay (ELISA), were compared to features of the corresponding human disease. The OVA+SEB model induced eosinophilic inflammation of upper and lower airways, with epithelial and basement membrane thickening, goblet cell hyperplasia and subepithelial fibrosis in the sinuses, along increased IgE production. Except local IgE in nasal lavage (NL), which was only increased in OVA+SEB group, all other features did not differ between OVA and OVA+SEB groups. Macro- or microscopic NP were not detected. With the notable exception of local IgE production, the addition of SEB did not induce additional inflammatory or structural change in the sinuses from mice exposed to and challenged with OVA. This model might represent a model for severe upper airway allergy rather than a specific model of human eCRSwNP.

Histomorphological Investigation of the Eye of the Tree Squirrel: A Preliminary Study

Abstract Squirrels are diurnal rodents with high visual acuity including unique properties well-suited for their natural environment. This study was conducted to explore some ocular microscopic features of tree-harbouring squirrels in the University of Ibadan, Ibadan, Nigeria. Two male squirrels were cage-trapped within the University premises. Light microscopic analysis was carried on paraffin-embedded eye samples harvested from the animals. The densely compacted stromal fibres, 351 ± 52.5 µm thick, formed the thickest part of the cornea, and the basement membrane of the corneal epithelium, 63.8 ± 13.0 µm thick, was notably positive with Periodic Acid Schiff (PAS) stain. Strong pigmentation was present at the choroid as well as the iridal and ciliary epithelia. The multiple layering of the retinal structure exhibited densely packed ganglion cells at the ganglion cell layer which together with the nerve fibre layer was observed to be thinnest at the more peripheral portion but becomes thicker towards the optic disc. Strongly positive glia fibrillary acidic protein (GFAP+) cells with their abundant fibrous processes were demonstrated immunohistochemically at the retinal nerve fibre layer and the optic nerve. Histological features of the retinal cellular components of the tree squirrels investigated has thus highlighted the structural adaptation of these animal species to their environmental arboreal habitat and diurnal lifestyle. Findings from this study, while further noted to be similar to that in human, showed that African tree squirrels represent promising rodent model for human retinal/ocular research.

Changes in Tight Junction Protein Expression Levels but Not Distribution in Commercial White and Brown Laying Hens Supplemented with Chondrus crispus or Ascophyllum nodosum Seaweed.

It is proposed that prebiotic diet supplements improve intestinal function, in part by improving the barrier function of the intestinal epithelium with an associated increase in the expression of tight junction proteins, including occludin and zonula occludens-1 (ZO-1). We examined the expression of these proteins in two strains of laying hens (Lohman LSL-lite (White) and Lohman Brown-lite (Brown)) who were supplemented or not with 3% Chondrus crispus or 0.5% Ascophyllum nodosum seaweeds from 31 to 72 weeks of age. Occludin was localized to the lateral surfaces and across the intestinal epithelium in all animals. Reactivity for ZO-1 was concentrated at the apicolateral epithelial cell membrane border. Mood's median test indicated that White hens may express more occludin in villus epithelium (median intensity 3.5 vs. 2.5 in Brown hens, p = 0.06) but less ZO-1 in the deep cryptal epithelium (median intensity 1.5 vs. 2.5 in Brown hens, p = 0.06). Western blotting also showed higher levels of occludin in White than Brown hens (p < 0.05). A decrease in ZO-1 Western blot expression was associated with Chondrus crispus supplementation in comparison to controls (p < 0.05), but not with Ascophyllum nodosum supplementation (p > 0.05). In conclusion, genetic strain and dietary seaweed supplements affect tight junction regulatory protein expression levels but do not impact the anatomical distribution, as seen in cryosections.

89Zr-ImmunoPET for the Specific Detection of EMP2-Positive Tumors.

Epithelial membrane protein-2 (EMP2) is upregulated in a number of tumors and therefore remains a promising target for mAb-based therapy. In the current study, image-guided therapy for an anti-EMP2 mAb was evaluated by PET in both syngeneic and immunodeficient cancer models expressing different levels of EMP2 to enable a better understanding of its tumor uptake and off target accumulation and clearance. The therapeutic efficacy of the anti-EMP2 mAb was initially evaluated in high- and low-expressing tumors, and the mAb reduced tumor load for the high EMP2-expressing 4T1 and HEC-1-A tumors. To create an imaging agent, the anti-EMP2 mAb was conjugated to p-SCN-Bn-deferoxamine (DFO) and radiolabeled with 89Zr. Tumor targeting and tissue biodistribution were evaluated in syngeneic tumor models (4T1, CT26, and Panc02) and human tumor xenograft models (Ramos, HEC-1-A, and U87MG/EMP2). PET imaging revealed radioactive accumulation in EMP2-positive tumors within 24 hours after injection, and the signal was retained for 5 days. High specific uptake was observed in tumors with high EMP2 expression (4T1, CT26, HEC-1-A, and U87MG/EMP2), with less accumulation in tumors with low EMP2 expression (Panc02 and Ramos). Biodistribution at 5 days after injection revealed that the tumor uptake ranged from 2 to approximately 16%ID/cc. The results show that anti-EMP2 mAbs exhibit EMP2-dependent tumor uptake with low off-target accumulation in preclinical cancer models. The development of improved anti-EMP2 Ab fragments may be useful to track EMP2-positive tumors for subsequent therapeutic interventions.

Abnormal functional lymphoid tolerance and enhanced myeloid exocytosis are characteristics of resting and stimulated PBMCs in cystic fibrosis patients.

Cystic Fibrosis (CF) is the commonest genetically inherited disease (1 in 4,500 newborns) and 70% of people with CF (pwCF) harbour the F508Del mutation, resulting in misfolding and incorrect addressing of the channel CFTR to the epithelial membrane and subsequent dysregulation of fluid homeostasis. Although studies have underscored the importance and over-activation of myeloid cells, and in particular neutrophils in the lungs of people with CF (pwCF), relatively less emphasis has been put on the potential immunological bias in CF blood cells, at homeostasis or following stimulation/infection. Here, we revisited, in an exhaustive fashion, in pwCF with mild disease (median age of 15, median % FEV1 predicted = 87), whether their PBMCs, unprimed or primed with a 'non specific' stimulus (PMA+ionomycin mix) and a 'specific' one (live P.a =PAO1 strain), were differentially activated, compared to healthy controls (HC) PBMCs. 1) we analysed the lymphocytic and myeloid populations present in CF and Control PBMCs (T cells, NKT, Tgd, ILCs) and their production of the signature cytokines IFN-g, IL-13, IL-17, IL-22. 2) By q-PCR, ELISA and Luminex analysis we showed that CF PBMCs have increased background cytokines and mediators production and a partial functional tolerance phenotype, when restimulated. 3) we showed that CF PBMCs low-density neutrophils release higher levels of granule components (S100A8/A9, lactoferrin, MMP-3, MMP-7, MMP-8, MMP-9, NE), demonstrating enhanced exocytosis of potentially harmful mediators. In conclusion, we demonstrated that functional lymphoid tolerance and enhanced myeloid protease activity are key features of cystic fibrosis PBMCs.

The role of desmoglein-2 in kidney disease

Desmosomes are multi-protein cell-cell adhesion structures supporting cell stability and mechanical stress resilience of tissues; best described in skin and heart. The kidney is exposed to various mechanical stimuli and stress, yet little is known about kidney desmosomes. In healthy kidneys, we found desmosomal proteins located at the apical-junctional complex in tubular epithelial cells. In four different animal models and patient biopsies with various kidney diseases, desmosomal components were significantly upregulated and partly miss-localized outside of the apical-junctional complexes along the whole lateral tubular epithelial cell membrane. The most upregulated component was desmoglein-2 (Dsg2). Mice with constitutive tubular epithelial cell-specific deletion of Dsg2 developed normally and other desmosomal components were not altered in these mice. When challenged with different types of tubular epithelial cell injury (unilateral ureteral obstruction, ischemia-reperfusion, and 2,8-dihydroxyadenine crystal nephropathy) we found increased tubular epithelial cell apoptosis, proliferation, tubular atrophy, and inflammation compared to wild type mice in all models and time points. In vitro, silencing DSG2 via siRNA weakened cell-cell adhesion in HK-2 cells and increased cell death. Thus, our data show a prominent upregulation of desmosomal components in tubular cells across species and diseases and suggest a protective role of Dsg2 against various injurious stimuli.

Integrated analyses of the genetic and clinicopathological features of cholangiolocarcinoma: cholangiolocarcinoma may be characterized by mismatch-repair deficiency.

Cholangiolocarcinoma (CLC) is a primary liver carcinoma that resembles the canals of Hering and that has been reported to be associated with stem cell features. Due to its rarity, the nature of CLC remains unclear, and its pathological classification remains controversial. To clarify the positioning of CLC in primary liver cancers and identify characteristics that could distinguish CLC from other liver cancers, we performed integrated analyses using whole-exome sequencing (WES), immunohistochemistry, and a retrospective review of clinical information on eight CLC cases and two cases of recurrent CLC. WES demonstrated that CLC includes IDH1 and BAP1 mutations, which are characteristic of intrahepatic cholangiocarcinoma (iCCA). A mutational signature analysis showed a pattern similar to that of iCCA, which was different from that of hepatocellular carcinoma (HCC). CLC cells, including CK7, CK19, and EpCAM, were positive for cholangiocytic differentiation markers. However, the hepatocytic differentiation marker AFP and stem cell marker SALL4 were completely negative. The immunostaining patterns of CLC with CD56 and epithelial membrane antigen were similar to those of the noncancerous bile ductules. In contrast, mutational signature cluster analyses revealed that CLC formed a cluster associated with mismatch-repair deficiency (dMMR), which was separate from iCCA. Therefore, to evaluate MMR status, we performed immunostaining of four MMR proteins (PMS2, MSH6, MLH1, and MSH2) and detected dMMR in almost all CLCs. In conclusion, CLC had highly similar characteristics to iCCA but not to HCC. CLC can be categorized as a subtype of iCCA. In contrast, CLC has characteristics of dMMR tumors that are not found in iCCA, suggesting that it should be treated distinctly from iCCA. © 2024 The Pathological Society of Great Britain and Ireland.

Proteomic analyses of urinary exosomes identify novel potential biomarkers for early diagnosis of sickle cell nephropathy, a sex-based study.

Sickle cell nephropathy (SCN) is a leading cause of morbidity and mortality in sickle cell disease (SCD). Early intervention is crucial for mitigating its effects. However, current diagnostic methods rely on generic tests and may not detect SCN until irreversible renal damage occurs. Therefore, specific biomarkers for early diagnosis of SCN are needed. Urinary exosomes, membrane-bound vesicles secreted by renal podocytes and epithelial cells, contain both common and cell type-specific membrane and cytosolic proteins, reflecting the physiologic and pathophysiologic states of the kidney. Using proteomics, we analyzed the proteomes of urinary exosomes from humanized SCD mice at 2months (without albuminuria) and 4months (with albuminuria) of age. Excretion of 164 proteins were significantly increased and 176 proteins was significantly decreased in the exosomes when mice developed albuminuria. Based on the relevance to SCD, chronic kidney disease and Western blot confirmation in mice, we analyzed protein abundance of heparanase, cathepsin C, α2-macroglobulin and sarcoplasmic endoplasmic Ca2+ ATPase-3 (SERCA3) in the urinary exosomes and urine of 18 SCD subjects without albuminuria and 12 subjects with albuminuria using Western blot analyses. Both male and female subjects increased or tended to increase the excretion of these proteins in their urinary exosomes upon developing albuminuria, but female subjects demonstrated stronger correlations between the excretion of these proteins and urine albumin creatinine ratio (UACR) compared to male subjects. In contrast, exosomal excretion of Tamm-Horsfall protein, β-actin and SHP-1 was independent of albuminuria. These findings provide a foundation for a time-course study to determine whether increases in the levels of these proteins precede the onset of albuminuria in patients, which will help determine the potential of these proteins as biomarkers for early detection of SCN.

АНАЛИТИКА ПАРАМЕТРОВ САЛИВАРНОГО СТАТУСА СТУДЕНТОВ-КУРИЛЬЩИКОВ ПРИ ИСПОЛЬЗОВАНИИ СПРЕЯ С МУКОПРОТЕКТОРОМ

Subject. The subject of this study is the salivary status in the patients.&#x0D; Objectives. The objective is to identify specifics of data analytics of the salivary status in student smokers effected by using a mucoptorotective dental spray. &#x0D; Methodology. The study is made by the Ural State Medical University Department of Preventive Dentistry and Propedeutics of Dental Disease, the Ural State Medical University Department of General Chemistry, the Ural Federal University Department of Control Systems Modeling. The objects of the study are unstimulated mixed saliva and a mucoptorotective spray that helps to protect the oral mucosa against inflammations, facilitates penetration across epithelial membranes, acts as a controlled multifunctional drug delivery system for parodontium tissues. The two study groups were formed from 20 volunteers in the age of 20 to 24 years old (4 women and 36 men, the average age was 22,35 years old): the first (main) group consisted of smoking patients, the second (reference) group consisted of non-smokers. The clinical assessment of the oral cavity of patients included: analysis of complaints, analysis of anamnesis, examination, evaluation of the hygiene index (OHI, Greene, Vermillion, 1964), dental caries severity index (using DMFT and DMFS indices), the state of gingival inflammation, PMA index (Parma). Unstimulated mixed saliva was studied, the quantitative analysis of the secretion was made by analyzing color, transparency, presence of inclusions, pH value, the functional activity of minor salivary glands. The statistical analysis of results was made using a PC with Microsoft Excel 2007 software program; the statistical significance was assessed using Student’s t-distribution by Statistica 6.0 software package.&#x0D; Conclusions. Given the reduction of objective values of index assessment of oral health status used as indicators of changes in oral health, the study of the data analytics of salivary status in student smokers in the course of using a mucoptorotective spray revealed the harmful effects of tobacco on salivary composition and parameters. The findings prove smoking-related oral homeostatic disruption promoting development and progression of dental diseases of the hard tissues, parodontium, oral mucosa. Application of the dental spray with titanium glycerosolvate aquacomplex is proved to be an effective way to prevent development and progression of such diseases.

Apical dehydration impairs the cystic fibrosis airway epithelium barrier via a β1-integrin/YAP1 pathway.

Defective hydration of airway surface mucosa is associated with lung infection in cystic fibrosis (CF), partly caused by disruption of the epithelial barrier integrity. Although rehydration of the CF airway surface liquid (ASL) alleviates epithelium vulnerability to infection by junctional protein expression, the mechanisms linking ASL to barrier integrity are unknown. We show here the strong degradation of YAP1 and TAZ proteins in well-polarized CF human airway epithelial cells (HAECs), a process that was prevented by ASL rehydration. Conditional silencing of YAP1 in rehydrated CF HAECs indicated that YAP1 expression was necessary for the maintenance of junctional complexes. A higher plasma membrane tension in CF HAECs reduced endocytosis, concurrent with the maintenance of active β1-integrin ectopically located at the apical membrane. Pharmacological inhibition of β1-integrin accumulation restored YAP1 expression in CF HAECs. These results indicate that dehydration of the CF ASL affects epithelial plasma membrane tension, resulting in ectopic activation of a β1-integrin/YAP1 signaling pathway associated with degradation of junctional proteins.

The Cyst Epithelium in Polycystic Kidney Disease Patients Displays Normal Apical-Basolateral Cell Polarity.

The main characteristic of polycystic kidney disease is the development of multiple fluid-filled renal cysts. The discovery of mislocalized sodium-potassium pump (Na,K-ATPase) in the apical membrane of cyst-lining epithelia alluded to reversal of polarity as a possible explanation for the fluid secretion. The topic of apical Na,K-ATPase in cysts remains controversial. We investigated the localization of the Na,K-ATPase and assessed the apical-basolateral polarization of cyst-lining epithelia by means of immunohistochemistry in kidney tissue from six polycystic kidney disease patients undergoing nephrectomy. The Na,K-ATPase α1 subunit was conventionally situated in the basolateral membrane of all immunoreactive cysts. Proteins of the Crumbs and partitioning defective (Par) complexes were localized to the apical membrane domain in cyst epithelial cells. The apical targeting protein Syntaxin-3 also immunolocalized to the apical domain of cyst-lining epithelial cells. Proteins of the basolateral Scribble complex immunolocalized to the basolateral domain of cysts. Thus, no deviations from the typical epithelial distribution of basic cell polarity proteins were observed in the cysts from the six patients. Furthermore, we confirmed that cysts can originate from virtually any tubular segment with preserved polarity. In conclusion, we find no evidence of a reversal in apical-basolateral polarity in cyst-lining epithelia in polycystic kidney disease.

(005) Immunohistochemical Staining of the 12:00 Vestibule in NPV Patients: First Ever Assessment

Abstract Introduction In 2004, Bornstein and colleagues performed immunohistochemical (IHC) staining of excised vestibular specimens in patients with vestibular pain. They demonstrated that these specimens contained &amp;gt; 8 CD117 immunopositive stained cells per high-power field (HPF), consistent with mast cells, and excess S100 stained immunopositive cells, consistent with nerves-far more compared to control tissue. However, Bornstein et al. only studied the 1:00-11:00 vestibule in this condition, now referred to as neuroproliferative vestibulodynia (NPV). To the best of our knowledge, the 12:00 region of the vestibule, below the clitoral frenulae and above the urethral meatus, has not been examined with IHC staining. Pain in the 12:00 region can be particularly bothersome for patients and poses several challenges for successful treatment. Objective To report IHC staining findings in the excised 12:00 vestibule specimen and associated clinical characteristics of NPV patients. Methods Retrospective chart review performed. Slides of IHC-stained vestibular tissue specimens from the 12:00 vestibule were examined and high-resolution digital microscopy images were captured under 100x and 200x magnification. A least 2 photomicrographs at both magnifications were taken for each slide that included representative areas of epithelial basement membrane and the adjacent subepithelial regions. Fractional area of positive immunostaining in all photomicrographs was assessed and mean values calculated using computer-assisted histometry by ImageJ. Results A total of 50 patients had complete vestibulectomy including 12:00 and 3 had regional vestibulectomy for only the 12:00 area. Using manual counting as applied by Bornstein et al., 53 excised 12:00 specimens stained for CD117 had a median immunopositive cell count, consistent with mast cells, of 29.5, greater than the described 8 mast cells per HPF. Using computer-assisted histometry, tissue stained for CD117 had a median fractional area of 0.73 in the 12:00 region. Tissues stained for PGP9.5 had a median fractional area of 0.31 in the 12:00 region. Overall, there was no difference between lifelong NPV (LNPV) and acquired NPV (ANPV) patients in the cell count or median fractional area for CD117-immunopositive or PGP9.5-immunopositive staining in the 12:00 region. In LNPV patients who had excision of both the 1:00-11:00 and 12:00 regions, the 12:00 region had significantly less PGP9.5 immunopositive fractional area than the 1:00-11:00 region of the vestibule (p = 0.001). Their H&amp;E pathology findings, including severity grading of the subepithelial inflammatory infiltrate, did not predict the IHC assessment of either CD117 or PGP9.5 in the 12:00 region. The median cotton-tipped swab test pain score was 5 out of 10 for the 12:00 region vs 7 for the rest of the vestibule. Conclusions Current surgical practices often do not include the 12:00 region, likely due to lack of data demonstrating excess mast cells and nerves in this specific region. Our results suggest that there are, in fact, a high density of immunopositive histochemical stains consistent with mast cells and nerves in the 12:00 region and high reported pain scores in both 12:00 and 1:00-11:00 vestibule. Thus, NPV surgical treatments should include, when appropriate, the 12:00 vestibule, as NPV is a field disease involving the entire vestibule. Disclosure No.

(004) Correlations Between Immunohistochemical Staining and Pain-Related Assessments in Patients with Neuroproliferative Vestibulodynia

Abstract Introduction A clinically suspected diagnosis of neuroproliferative vestibulodynia (NPV) can be confirmed by examining immunohistochemical (IHC) staining of excised vestibular specimens. Compared to controls, specimens from NPV patients have been found to contain &amp;gt;8 mast cells per high-power field (HPF) and increased density of nerves. Objective To assess for correlations between patient reported pain-related measures and computer-assisted histometry of excised vestibulectomy specimen IHC staining with CD117 (marker for mast cells) and PGP9.5 (marker for nerves) in a cohort of histopathologically confirmed NPV patients. Methods Patients (n=65) with lifelong or acquired NPV undergoing vestibulectomy had IHC-staining of the vestibular tissue. Tissue sections from the 1:00-11:00 and/or 12:00 regions of the vestibule were examined and high-resolution images were captured using a microscope at 100x and 200x magnification. A minimum of 2 photomicrographs per magnification were taken for each tissue section that included epithelial basement membrane and adjacent subepithelium representative of the majority of immunostained tissue. Fractional area of positive immunostaining of all photomicrographs was determined using computer-assisted histometry by ImageJ. Mean fractional area was determined from 3 separate measurements of each photomicrograph. Correlations were made between density of IHC staining and the following assessments: pain domain of the Female Sexual Function Index (FSFI), the Short Form McGill Pain Questionnaire (SF-MPQ), and cotton-tipped swab testing. We also examined correlations with the Patient Global Impression of Improvement (PGI-I), a treatment response index and indirect assessment of pain. Data were analyzed using Spearman correlations and the Mann-Whitney test. Results While all patients reported high levels of pain, there were no correlations between CD117- or PGP9.5-immunopositive mean fractional area and FSFI pain domain or SF-MPQ scores. There was no difference in immunopositive mean fractional area between lifelong and acquired NPV. A positive correlation between fractional area of CD117 immunostaining in the 1:00-11:00 region of the vestibule and cotton-tipped swab test pain score approached but did not reach statistical significance (r = 0.24, p = 0.063). Fractional area of PGP9.5 immunostaining was negatively correlated with PGI-I scores (r = -0.50, p = 0.006) in the 1:00-11:00 region of the vestibule. Lower PGI-I scores are indicative of greater improvement after surgical intervention. No other correlations were observed between immunostaining and PGI-I or cotton-tipped swab testing scores. Likewise, SF-MPQ domain scores had no correlation to PGI-I or cotton-tipped swab testing. Median cotton-tipped swab testing pain scores were significantly higher (p &amp;lt; 0.001) in patients with lifelong NPV (7.6) compared to those with acquired NPV (5.7). Conclusions The lack of correlations between immunopositive staining and multiple pain-related assessment scores suggests a non-linear threshold for mast cell accumulation and nerve proliferation that produces pain symptoms for all NPV patients. Cotton-tipped swab pain scores were more closely associated with density of CD117 immunostaining, while clinical improvement in pain symptoms was significantly correlated with density of PGP9.5 immunostaining. The fact that patients with lifelong NPV had significantly more pain on cotton-tipped swab testing than the acquired NPV subgroup may be related to duration of the condition. Disclosure No.

Gastric Perineurioma: A Rare Entity with Molecular Analysis and Literature Review.

Perineuriomas of the gastrointestinal tract are benign neoplasms that commonly develop in the distal colon and are identified during screening colonoscopy; however, perineuriomas of the stomach are exceedingly rare and less frequently identified. Differentiating gastric perineuriomas from other more serious gastric neoplasms is critical to avoid unnecessarily aggressive treatments. Thus far, only six patients with gastric perineurioma have been described, and the molecular characterization of this entity is still lacking. We report a 52-year-old woman who presented with abdominal pain and gastric acid reflux and was found to have a 1.5 cm subepithelial gastric neoplasm composed of bland spindle cells displacing the gastric glands with no cytologic atypia or mitotic activity, suggesting a benign spindle cell neoplasm. Immunohistochemical analysis showed reactivity for perineurial markers glucose transporter-1 and epithelial membrane antigen, consistent with benign gastric perineurioma. DNA extracted from the tissue was used for a capture-based target sequence enrichment panel followed by Illumina next-generation sequencing and targeted bioinformatic analysis for oncogenic alterations within defined disease-associated target regions. No sequence variants in the BRAF gene were identified. This rare case of gastric perineurioma helps solidify our understanding of how to discern various types of gastric neoplasms through traditional laboratory analysis alongside genetic sequencing approaches. Although extremely rare, gastric perineurioma should be kept in the differential diagnosis when assessing spindle cell gastric tumors to avoid unnecessary therapies, and physicians should understand the molecular characteristics of benign versus malignant tumors.

Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis.

Acanthamoeba keratitis (AK) is a severe, rare protozoal infection of the cornea. Acanthamoeba can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by Acanthamoeba that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in Acanthamoeba disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.

Non-professional efferocytosis of Salmonella-infected intestinal epithelial cells in the neonatal host.

The intestinal epithelium is the first line of defense against enteric pathogens. Removal of infected cells by exfoliation prevents mucosal translocation and systemic infection in the adult host, but is less commonly observed in the neonatal intestine. Instead, here, we describe non-professional efferocytosis of Salmonella-infected enterocytes by neighboring epithelial cells in the neonatal intestine. Intestinal epithelial stem cell organoid cocultures of neonatal and adult cell monolayers with damaged enterocytes replicated this observation, confirmed the age-dependent ability of intestinal epithelial cells for efferocytosis, and identified the involvement of the "eat-me" signals and adaptors phosphatidylserine and C1q as well as the "eat-me" receptors integrin-αv (CD51) and CD36 in cellular uptake. Consistent with this, massive epithelial cell membrane protrusions and CD36 accumulation at the contact site with apoptotic cells were observed in the infected neonatal host in vivo. Efferocytosis of infected small intestinal enterocytes by neighboring epithelial cells may represent a previously unrecognized mechanism of neonatal antimicrobial host defense to maintain barrier integrity.

Interplay between Microbiota and γδ T Cells: Insights into Immune Homeostasis and Neuro-Immune Interactions.

The gastrointestinal (GI) tract of multicellular organisms, especially mammals, harbors a symbiotic commensal microbiota with diverse microorganisms including bacteria, fungi, viruses, and other microbial and eukaryotic species. This microbiota exerts an important role on intestinal function and contributes to host health. The microbiota, while benefiting from a nourishing environment, is involved in the development, metabolism and immunity of the host, contributing to the maintenance of homeostasis in the GI tract. The immune system orchestrates the maintenance of key features of host-microbe symbiosis via a unique immunological network that populates the intestinal wall with different immune cell populations. Intestinal epithelium contains lymphocytes in the intraepithelial (IEL) space between the tight junctions and the basal membrane of the gut epithelium. IELs are mostly CD8+ T cells, with the great majority of them expressing the CD8αα homodimer, and the γδ T cell receptor (TCR) instead of the αβ TCR expressed on conventional T cells. γδ T cells play a significant role in immune surveillance and tissue maintenance. This review provides an overview of how the microbiota regulates γδ T cells and the influence of microbiota-derived metabolites on γδ T cell responses, highlighting their impact on immune homeostasis. It also discusses intestinal neuro-immune regulation and how γδ T cells possess the ability to interact with both the microbiota and brain.

The biophysical and biochemical polarization of the epithelial cell plasma membrane

The biophysical and biochemical polarization of the epithelial cell plasma membrane

The overlap Stevens-Johnson syndrome due to meropenem administration. Clinical case and nursing care

. The overlap Stevens-Johnson syndrome due to meropenem administration. Clinical case and nursing care. A case of overlap Stevens-Johnson syndrome caused by meropenem administration is described. It is a rare cutaneous reaction due to delayed hypersensitivity to drugs characterised by the destruction and separation of the skin epithelium and mucous membranes, affecting between 10% and 29% of the body surface area. The clinical description of the case and a detailed description of nursing management and interventions based on the available literature are reported.

Interaction between Permeation Enhancers and Lipid Bilayers.

Permeation enhancers (PEs) are a class of molecules that interact with the epithelial membrane and transiently increase its transcellular permeability. Although there have been few clinical trials of PE coformulated drugs, the mechanism of action of PEs remains elusive. In this paper, the interaction between two archetypes of PEs [salcaprozate sodium (SNAC) and sodium caprate (C10)] and membranes is investigated with extensive all-atom molecular dynamics simulations. The simulations show that (1) the association between the neutral PEs and membranes is favored in free energy, (2) the propensity of neutral PE aggregation is larger in aqueous solution than in lipid bilayers, (3) the equilibrium distribution of neutral PEs in membranes is fast, e.g., accessible with unbiased MD simulations, and (4) the micelle of neutral PEs formed in aqueous solution does not rupture the membranes (e.g., not forming pores or breaking up the membrane) under simulation conditions. All results combined, this study indicates that PEs insert into the membranes in an equilibrium or near equilibrium process. This study lays the foundation for future investigations of how PEs impact the free energy of permeation for small molecules.