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Background Fish skin represents an ancient vertebrate mucosal surface, sharing characteristics with other mucosal surfaces including those of the intestine. The skin mucosa is continuously exposed to microbes in the surrounding water and is therefore important in the first line defense against environmental pathogens by preventing bacteria from accessing the underlying surfaces. Understanding the microbe-host interactions at the fish skin mucosa is highly relevant in order to understand and control infection, commensalism, colonization, persistence, infection, and disease. Here we investigate the interactions between the pathogenic bacteria Aeromonas salmonicida (A. salmonicida) and Yersinia ruckeri (Y. ruckeri), respectively, and the skin mucosal surface of Atlantic salmon fry using AFM force spectroscopy. Results The results obtained revealed that when retracting probes functionalized with bacteria from surfaces coated with immobilized mucins, isolated from salmon mucosal surfaces, rupture events reflecting the disruption of adhesive interactions were observed, with rupture strengths centered around 200 pN. However, when retracting probes functionalized with bacteria from the intact mucosal surface of salmon fish fry no adhesive interactions could be detected. Furthermore, rheological measurements revealed a near fluid-like behavior for the fish fry skin mucus. Taken together, the experimental data indicate that the adhesion between the mucin molecules within the mucous layer may be significantly weaker than the interaction between the bacteria and the mucin molecules. The bacteria, immobilized on the AFM probe, do bind to individual mucins in the mucosal layer, but are released from the near fluid mucus with little resistance upon retraction of the AFM probe, to which they are immobilized. Conclusion The data provided in the current paper reveal that A. salmonicida and Y. ruckeri do bind to the immobilized mucins. However, when retracting the bacteria from intact mucosal surfaces, no adhesive interactions are detected. These observations suggest a mechanism underlying the protective function of the mucosal surface based on the clearing of potential threats by adhering them to loosely attached mucus that is subsequently released from the fish skin.

Mucous membrane pemphigoid (MMP) is a systemic cicatrizing autoimmune disease that primarily affects orificial mucous membranes, such as the conjunctiva, the nasal cavity, the oropharynx, and the genitalia. Ocular involvement occurs in about 70% of all MMP cases. Ocular MMP (OcMMP) also encompasses the conditions linear immunoglobulin A disease, mucosal dominated epidermolysis bullosa acquisita, and anti-laminin 332/anti-epiligrin/anti-laminin 5 pemphigoid. It is a complex clinical entity that may lead to ocular surface failure and result in inflammatory and infectious complications, as well as potentially devastating visual loss. Early diagnosis and appropriate treatment are of paramount importance and require a high level of expertise as this condition can be extremely challenging to diagnose and treat even for experienced clinicians. In this review we provide an up-to-date insight on the pathophysiology of OcMMP, with an emphasis on the current state of its diagnostics and therapeutics. Our the aim is to increase our understanding of OcMMP and highlight modern diagnostic and therapeutic options.

Bullous pemphigoid (BP) is the most common type of autoimmune bullous disease and is characterized by the presence of circulating anti-BP180 and/or anti-BP230 autoantibodies. Patients with BP often present with tense blisters and erythema, mainly on the trunk and limbs, but a few patients also have mucosal involvement. In this article, we discuss the fact that BP patients with mucosal involvement tend to have more serious conditions and their disease is more difficult to control. Potential risk factors for mucous involvement include earlier age at onset, drugs such as dipeptidyl peptidase-4 inhibitors, cancer, and blood/serum biomarkers, including lower eosinophil count, higher erythrocyte sedimentation rate, IgG autoantibodies against both the NH2- and COOH-termini of BP180, and the absence of anti-BP230 antibodies. IgA and C3 deposition at the dermo-epidermal junction may also be present. Understanding these risk factors may benefit earlier diagnosis of these patients and promote the development of novel treatments. What's more, it's helpful in deeper understanding of BP development and the relationship between BP and mucous membrane pemphigoid (MMP).

Introduction: Histoplasmosis is the main opportunistic infection and cause of death in HIV-infected persons living with HIV in French Guiana and probably in most of Latin America. The objective of the present study was to compare cutaneomucous histoplasmosis to non-cutaneomucous histoplasmosis in French Guiana. Methods: Between 1981 and 2014 AIDS-related disseminated histoplasmosis patients followed in the three hospitals of French Guiana were retrospectively studied. Only proven incident cases of histoplasmosis, either by pathology and/or mycological analysis, were considered. Mucocutaneous histoplasmosis was ascertained by a positive mucosal or cutaneous biopsy. Results: Thirty-one patients had mucocutaneous lesions, and 318 had no mucocutaneous lesions. Patients with cutaneomucous lesions were more likely to have had prior opportunistic infections (35.5%) than those who did not have cutaneomucous lesions (19.5%). They were more likely to be very severely immunocompromised (CD4 count &lt, 50) (90.3% versus 62.8%) and less likely to have digestive signs (32.3% versus 74.1%) and superficial adenopathies (29% versus 50.2%) than those without cutaneomucous lesions. In terms of simple biological examinations, patients with cutaneomucous lesions had fewer signs of cholestasis. The diagnosis was significantly more likely to be performed by direct examination and pathology in those with cutaneomucous lesions than in those without such lesions. On the contrary, patients with cutaneomucous lesions were less likely to be diagnosed by fungal culture than those without cutaneomucous lesions. There was a greater but non-significant risk of early death in those with cutaneomucous lesions relative to those without (OR = 2.28 (95%CI = 0.83&ndash, 5.7), p = 0.056. Conclusions: Mucocutaneous forms were associated with more profound immunosuppression and perhaps risk of early death. They are easily accessible for diagnosis.

Background and Objectives: No single optimal test reliably determines the pancreatic cyst subtype. Following EUS-FNA, the 'string sign' test can differentiate mucinous from nonmucinous cysts. However, the interobserver variability of string sign results has not been studied. Methods: An experienced endosonographer performed EUS-FNA of pancreatic cysts on different patients and was recorded on video performing the string sign test for each. The videos were shared internationally with 14 experienced endosonographers, with a survey for each video: 'Is the string sign positive?' and 'If the string sign is positive, what is the length of the formed string?' Also asked 'What is the cutoff length for string sign to be considered positive?' Interobserver variability was assessed using the kappa statistic (κ). Results: A total of 112 observations were collected from 14 endosonographers. Regarding string sign test positivity, κ was 0.6 among 14 observers indicating good interrater agreement (P < 0.001) while κ was 0.38 when observers were compared to the index endosonographer demonstrating marginal agreement (P < 0.001). Among observations of the length of the string in positive samples, 89.8% showed >5 mm of variability (P < 0.001), indicating marked variability. There was poor agreement on the cutoff length for a string to be considered positive. Conclusion: String sign of pancreatic cysts has a good interobserver agreement regarding its positivity that can help in differentiating mucinous from nonmucinous pancreatic cysts. However, the agreement is poor on the measured length of the string and the cutoff length of the formed string to be considered a positive string sign.

Mucocele is a common salivary gland disorder that can appear in the lacrimal sac, paranasal sinuses, oral cavity, appendix, or gall bladder. These lesions occur due to mucous accumulation resulting from the alteration of minor salivary glands. Lower lip is the most common site of occurrence of these lesions in the oral cavity and most probable cause is trauma or habit of lip biting. Diagnosis is mainly clinical due to its pathognomonic presentation. We report a case series of mucocele in children treated by conventional surgical excision of the lesion.

Lichen is a common chronic inflammatory dermatitis that can affect the skin, mucous membranes and phaneres. The simultaneous involvement of the three compartments is rare and testifies to the severity and activity of the disease. We present a case of this triple involvement. However, the complete muco-cutaneous and phanerienic forms are rare, testify to the severity of the disease and justify a systemic treatment and a regular and long-term monitoring view the risk of degeneration of the mucous lesions. We report the case of this 60-old-man, followed for papular dermatosis, hyperpigmentary, very itchy, generalized, with involvement of the genital mucosa, in the form of erosive balanitis and nails of the hands and feet. The cutaneous histology was in favor of lichen. The biological examinations did not show any dysthyroidism, liver or autoimmune diseases. The patient was placed on systemic and topical corticosteroids. A pigmentogenic evolution of the cutaneous lesions, a beginning of bleaching of the nail lesions and a resistance of the genital lesions were noted.

Ostreopsis cf. ovata is a harmful benthic dinoflagellate, widespread along most of the Mediterranean coasts. It produces a wide range of palytoxin-like compounds and variable amounts of mucus that may totally cover substrates, especially during the stationary phase of blooms. Studies on different aspects of the biology and ecology of Ostreopsis spp. are increasing, yet knowledge on toxicity mechanism is still limited. In particular, the potential active role of the mucilaginous matrix has not yet been proven, although when mass mortalities have occurred, organisms have been reported to be covered by the typical brownish mucilage. In order to better elucidate toxicity dependence on direct/indirect contact, the role of the mucilaginous matrix and the potential differences in toxicity along the growth curve of O. cf. ovata, we carried out a toxic bioassay during exponential, stationary and late stationary phases. Simultaneously, a molecular assay was performed to quantify intact cells or to exclude cells presence. A liquid chromatography - high resolution mass spectrometry (LC-HRMS) analysis was also carried out to evaluate toxin profile and content in the different treatments. Our results report higher mortality of model organism, especially during the late stationary phase, when a direct contact between model organism and intact microalgal cells occurs (LC50-48h < 4 cells/ml on A. salina), although also growth medium devoid of microalgal cells but containing O. cf. ovata mucilage cause significant toxic effects. This finding is also supported by chemical analysis which shows the highest toxin content in pellet extract (95%) and around to 5% of toxins in the growth medium holding mucus, while the treatment deprived of both cells and mucilage didn’t contain any detectable toxins. Additionally, the connection between mucilaginous matrix and thecal plates, pores and trychocysts was explored by way of atomic force microscopy (AFM) to investigate cell surface at a sub-nanometer resolution, providing a pioneering description of cellular features.

A complete skin examination includes the evaluation of the scalp, genitalia, mucous membranes, and conjunctiva. In this study, the scalp and genitalia were not examined unless directed by the patient. We suspect that these areas were examined infrequently, since it is unusual for a woman to point out a pigmented vulvar lesion, and macular lesions on the scalp are usually invisible to the patient. The scalp examination is usually the most time-consuming part of a complete skin examination. Moreover, there was no mention whether mucous membranes or conjunctiva were included in the examination described in the study. Perhaps the title of the article would have more accurate as “Time Required for a Partial Skin Examination. . . .”

Respiratory tract lining fluids (RTLFs) are a heterogeneous group of substances covering the respiratory tract epithelial cells (RTECs) from nasal mucosa to alveoli. Antioxidant contained in the RTLFs can be expected to provide an initial defense against inhaled environmental toxins. The major antioxidants in RTLF include mucin, uric acid, protein (largely albumin), ascorbic acid, and reduced glutathione (GSH). RTLF antioxidants can be augmented by such processes as transudation/exudation of plasma constituents; RTEC secretory processes, including glandular mucus secretion; and cellular antioxidants derived from lysis of RTECs and of inflammatory cells. The antioxidant composition of RTLFs and their role in modulating normal and pathophysiologic RTEC functions under conditions of oxidative stress are yet to be fully characterized.