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International audience; Holothurians are marine invertebrates that are among the most widespread benthic megafauna communities by both biomass and abundance in shallow-water and deep-sea ecosystems, their functions supporting important ecological services worldwide. Despite their simple appearance as sea cucumbers, holothurians show a wide range of feeding practices. However, information on what and how these animals eat is scattered and potentially confusing. We provide a comprehensive review of holothurian nutrition in coastal and deep-sea ecosystems. First, we describe morphological aspects of holothurian feeding and the ultrastructure of tentacles. We discuss the two processes for food capture, concluding that mucus adhesion is likely the main method; two mucous cells, type-1 and type-2, possibly allow the adhesion and de-adhesion, respectively, of food particles. Secondly, this review aims to clarify behavioural aspects of holothurian suspensionand deposit-feeding. We discuss the daily feeding cycle, and selective feeding strategies. We conclude that there is selectivity for fine and organically rich particles, and that feeding through the cloaca is also a route for nutrient absorption. Third, we provide a wide description of the diet of holothurians, which can be split into two categories: living and non-living material. We suggest that Synallactida, Molpadida, Persiculida, Holothuriida and Elasipodida, ingest the same fractions, and emphasise the importance of bacteria in the diet of holothurians.

The olfactory organs of two African lungfishes,Protopterus amphibiusandP. dolloi, were investigated using a stereo microscope and a compound light microscope and were described anatomically, histologically, and histochemically. Like other lungfishes, these species present the following general features: i) elongated olfactory chamber (OC), ii) anterior nostril at the ventral tip of the upper lip, iii) posterior nostril on the palate of the oral cavity, iv) lamellae with multiple cell types such as olfactory receptor neurons, supporting cells, basal cells, lymphatic cells, and mucous cells (MC), and vi) vomero-like epithelial crypt (VEC) made of glandular epithelium (GE) and crypt sensory epithelium. Some of these features exhibit differences between species: MCs are abundant in both the lamellar and inner walls of the OC inP. amphibiusbut occur only in lamellae inP. dolloi. On the other hand, some between feature differences are consistent across species: the GE of bothP. amphibiusandP. dolloiis strongly positive for Alcian blue (pH 2.5)-periodic acid Schiff (deep violet coloration), and positive with hematoxylin and eosin and with Masson’s trichrome (reddish-brown staining), unlike the MCs of the two species which stain dark red with both Alcian blue (pH 2.5)-periodic acid Schiff and Masson’s trichrome but respond faintly to hematoxylin and eosin. The differing abundance of MCs in the two lungfishes might reflect different degrees in aerial exposure of the olfactory organ, while the neutral and acid mucopolysaccharide-containing VEC, as indicated by staining properties of the MCs, is evolutionary evidence thatP. amphibiusandP. dolloiare the closest living relatives to tetrapods, at least in the order Dipnoi.

In teleosts, the mucosal epithelial barriers represent the first line of defence against environmental challenges such as pathogens and environmental contaminants. Mucous cells (MCs) are specialised cells providing this protection through mucus production. Therefore, a better understanding of various MC quantification methods is critical to interpret MC responses. Here, we compare histological (also called traditional) quantification of MCs with a novel mucosal mapping method to understand the differences between the two methods' assessment of MC responses to parasitic infections and pollution exposure in shorthorn sculpins (Myoxocephalus scorpius). Overall, both methods distinguished between the fish from stations with different levels of pollutants and detected the links between MC responses and parasitic infection. Traditional quantification showed relationship between MC size and body size of the fish whereas mucosal mapping detected a link between MC responses and Pb level in liver. While traditional method gave numerical density, mucosal mapping gave volumetric density of the mucous cells in the mucosa. Both methods differentiated MC population in skin from those in the gills, but only mucosal mapping pointed out the consistent differences between filament and lamellar MC populations within the gills. Given the importance of mucosal barriers in fish, a better understanding of various MC quantification methods and the linkages between MC responses, somatic health and environmental stressors is highly valuable.

Aim: This study aimed to examine the intestinal histopathological lesions and mucous cell responses in the entire intestines of Nile tilapia administered with Lactobacillus rhamnosus GG (LGG)-mixed feed, after Aeromonas hydrophila challenge. Materials and Methods: Intestinal samples from fish fed with control normal diet or LGG-mixed feed (1010 colony-forming unit [CFU]/g feed) with or without A. hydrophila in phosphate-buffered saline challenge (7.46 × 108 CFU/mL/fish) were collected and processed for histopathological study. The mucous cell responses were evaluated using histochemistry, using Alcian blue (AB) at pH 2.5, AB at pH 1.0, and periodic acid-Schiff-AB at pH 2.5. The quantification of the intestinal mucous cell size and the staining character of each mucin type from the entire intestine were recorded and counted. Results: Histopathological study showed remarkable lesions only in the proximal intestine in fish infected with A. hydrophila, while LGG-fed fish had less intestinal damage, perhaps resulting from heterophil infiltration. Furthermore, a significant (p

Ageratum conyzoides Linn is a medicinal plant used for diverse ethnomedicinal applications including anti-ulcer treatment. Usually, protection of gastric mucosa from injury or ulceration is dependent on the efficacy of intrinsic or induced protective factors against erosive effects of aggressive factors. In this study, our aim was to ascertain the gastroprotective activity of methanolic leaf extracts of A. conyzoides L. and assess the associated roles of gastric mucous cells and p53 protein. This study involved 25 adult male Wistar rats divided into five groups (A-E). Groups A and E were used as normal and test controls while B-D were administered with extracts at 100, 300 and 500 mg/kg body weight for 28 days. Gastric mucosal injury was induced via pyloric ligation method. Gastric tissues were processed, stained with periodic acid-Schiff and immunostained for p53 protein (using monoclonal antibody). Stained sections were quantified using image-J software, data obtained were statistically analyzed. The results showed significant increase (p

Mucous cells, the microscopic structural hallmark of mucosal surfaces, are highly responsive to environmental changes. Here we report how the gills of Atlantic salmon (Salmo salar) smolts responded to peracetic acid (PAA), a potent oxidative disinfectant and a candidate chemotherapeutant in aquaculture, through the Mucosal Mapping showing mucous cell size, volumetric density and defence activity, coupled with two-way histopathological scoring strategies. Two hundred and forty smolts were exposed to therapeutic doses of PAA on two occasions. The initial exposure included a 5-min bathing at concentrations of 0, 0.6, 1.2, and 2.4 ppm PAA. After a two-week recovery, the treatment groups were re-exposed to the same PAA concentrations for 30 min. Gill samples were collected at 2 h, 2 days, and 2 weeks after each exposure. The dynamic changes (i.e., size, volumetric density and defence activity) of the mucous cells were analysed on the distinct mucous cell populations in the gill filament and the lamella, as well as the lamellar thickness. Lamellar mucous cells were always significantly smaller (2 and 8–11% volume) giving defence activities (combination of mean mucous cell area and volumetric density in a given tissue) of 0.1–0.4 for lamellae and about 0.6–1.4 for filaments, consistent with the functions of these branchial areas. A transient sub-acute mucous cell hypertrophy was a striking response in the gill lamella to PAA during the initial and re-exposure, particularly demonstrated by the groups exposed to 0.6 and 1.2 ppm where this size change was significant. Nonetheless, the recovery was quick, suggesting more an effect of general stress than dose of PAA. Similarly, a transient reduction in hyperplasia was noted as mucous cell density decreased on the filament, but generally significant hyperplasia was not detected, and volumetric density remained unaltered regardless of treatment doses and duration of exposure. The defence activity of the lamella and the filament demonstrated a transient tendency to decrease after the initial exposure but was minimally affected by re-exposure. Lamellar thickness was not markedly affected by the highest PAA dose and overall was positively correlated with mucous cell size. The results from two independent histopathological scorings revealed that at least 93% of the evaluated gill filaments per fish were categorised as healthy. Taken together, mucous cells in the gills of salmon smolts responded with transient hypertrophy of mucous cells to therapeutic doses of PAA however the impact was minimal, and the mucosal morphometrics were in agreement with the marginal alterations in tissue structure and integrity. The data suggest that the PAA doses used in the study are safe for salmon and do not pose substantial impact on gill mucosal health.

The achenes’ micromorphological structure of six Artemisia species (A. absinthium, A. annua, A. argyi, A. dracunculus, A. marschalliana, and A. vulgaris) distributed in Ukraine was investigated with the aim to identify taxonomically significant carpological features for the studied species. Fruits were collected from wild plants growing in the recreation areas of Kyiv and from the plants hosted in the living collection of the M.M. Gryshko National Botanical Garden of the NAS of Ukraine. Macromorphological features were studied with a binocular microscope Stemi 2000 Carl Zeiss. The ultrastructure of the surface was studied using a scanning electron microscope JSM-6700F JEOL, in the mode of secondary electron emission. Carbon spraying was performed using vacuum thermal evaporation of the vacuum universal post VUP-5M SELMI; platinum spraying was performed with an ion-plasma etching device JFC-1600 JEOL. All investigated species have a well-expressed, true, multicellular, symmetrical, multi-row carpopodium but differ by its shape. The surface of A. annua achenes is reticulate-pitted due to the specific structure of the exocarp and the exotests located below it. Species with lobed and continuous apical rim and species without a rim around the place of attachment of the corolla were found. It was established that the primary ultrastructure of investigated fruits is caused by the shape and character of mucous cell arrangement; epidermal cells of the exocarp are mostly compressed, without clear boundaries. Mostly a thin and inconspicuous cuticle, sometimes wrinkled, with layers and small outgrowths, causes the secondary ultrastructure of these fruits. We believe that the mentioned carpological features may be used as additional criteria in combination with other features to identify studied species.

Fish gills are heavily exposed to the external milieu and may react against irritants with different cellular responses. We describe variations in mucous cell counts in gills from healthy Atlantic salmon (Salmo salar) presmolts in five recirculating aquaculture system (RAS) farms and one flow-through farm. Based on certain criteria, mucous cells were histologically quantified in a defined lamellar region of the gills and the counts were analysed. Immunohistochemistry (IHC) was used to investigate epithelial responses. The median number of total mucous cells in the defined region was 59 per fish. Between the farms, the medians varied from 31 to 101 with the lowest in the flow-through farm. A regression model was fitted with "total mucous cells" as the dependent variable and with "fish length" and "fish farm" as independent variables. The proportion of variation in mucous cell counts explained by the model was twice as high when "fish farm" was included compared to only "fish length." IHC revealed proliferative responses in coherence with high mucous cell numbers. Conclusively, the variation in mucous cell counts depends on combined farm-related factors. Establishing a baseline for mucous cell counts is fundamental in the development of high-throughput monitoring programmes of gill health in farmed fish.

When salmon lice, Lepeophtheirus salmonis, infect Atlantic salmon, they are typically removed by chemical or mechanical treatments. Delousing side effects can lead to poor welfare outcomes for fish, however reducing lice abundance in farms is crucial to reduce their ecological impacts. To determine which delousing treatments causes the highest salmon mortality, we used national-level databases to compare mortality for all delousing treatments (i.e. in-feed, bath, well-boat based, cage-based, thermal and mechanical treatments) used from 2012 to 2015 in Norway. As hydrogen peroxide (H2O2) is one of the riskiest delousing treatments with high mortality levels, we determined how hydrogen peroxide concentration (0, 1, 1.25, 1.5, 1.75, 2 and 2.25 g L− 1) for 20 min at 10 °C influenced post-smolt salmon mortality and mucous cells, pre-adult lice attachment, and the re-infection success of lice copepodids. H2O2 concentration strongly affected salmon mortality, but did not alter mucous cell area or density, pre-adult lice removal efficiency, or the re-infection success of lice copepodids. We recorded salmon mortality of 0% at 1 g L− 1, 18% at 1.5 g L− 1 and 100% at 2.25 g L− 1. Further, previous exposure to lice had no effect on salmon welfare or the likelihood of re-infection, as salmon mortality and copepodid infection success did not differ for salmon infected with lice and treated, or salmon not infected with lice and treated. We found discrepancies in salmon mortality between our experiment and industry observed mortality, with higher mortalities observed in our experiment compared to the industry. This is most likely due to the overestimation of water volume during in-cage treatments at farms, and also less organic matter present during our experiment. As we found no difference in lice removal efficacies between 1 and 2 g L− 1 and salmon mortality was high at concentrations of 1.5 g L− 1 upwards, we do not recommend increasing H2O2 dosage during treatment as a form of combatting H2O2 resistance in lice.

The present work was undertaken with the aim to deduce morphological adaptations in skin of an angler catfish Chaca chaca by means of scanning electron microscopy. The fish is nocturnal, bottom dwelling, sluggish, ambush predator, lives in sand, mud, or soft substrates often buried and camouflaged for protection and to feed. The surface of the epidermis is covered with polygonal epithelial cells, each having surface relief of microridges forming intricate patterns. In between epithelial cells irregularly distributed mucous cell openings, randomly distributed epidermal specialized structures, taste buds, and neuromasts are discernible. The epidermal specialized structures are keratinized. These are either irregularly the rounded elevated plaque like or the cone shaped structures. The superficial keratinized cells could frequently be discernible exfoliated at the surface. At intervals, characteristic epidermal projections could be observed. Surface of these projections at intervals is differentiated into short stumpy protuberances, each bearing a taste bud at its summit. Further, near the basal portion of these epidermal projections, conical, or rounded plaque like epidermal specialized structures are also discernible. The surface sculpture of the skin of Chaca chaca is associated with the structural and functional significance and physiological adaptations of the epidermis with respect to its ecological niche.

SUMMARY: The structural characteristics of the skin, types and distribution of mucous cells of Yangtze sturgeon (Acipenser dabryanus) were studied at the light microscope level, stained with Haematoxylin-eosin (HE) and Alcian blue-periodie acid Schiff (ABPAS). The skin of both was composed of epidermis and dermis. The dermis was divided into stratum spongiosum and stratum compactum. The stained color of stratum compactum was stained more deeply than that of stratum spongiosum. The skin thickness displayed differences in the fish at different body positions. The thickest of epidermis layer was on the dorsal region for Yangtze sturgeon, reversely, the thinnest was the mandibular region; Stratum spongiosum on the mandibular region was the thickest, the stratum spongiosum of the maxillary region was not obvious. In summary, keratinized spines, a kind of keratin derivative, are widely distributed in the mandibular, ventral, dorsal, and caudal peduncle skin surface for Yangtze sturgeon, and some pit organs mainly present in the skin surface of the maxillary and ventral regions. In short, the small amount of mucous cells in the skin of Yangtze sturgeon and the type of mucous cell were main Type IV, nevertheless there was a distribution of a few Type III.

This study aimed to evaluate the sedative and anesthetic potential of the essential oil (PHEO) and hydrolate (PHH) from the fruit of Protium heptaphyllum and the isolated compounds (IC) of PHEO in tambaqui (Colossoma macropomum) juveniles. Fish were placed in aquaria with different concentrations of PHEO, PHH or IC (sabinene, terpinen-04-ol, γ-terpinene and α-pinene) to evaluate sedative and anesthetic efficacy. In another experiment, fish were transported for 22 h with 10% anesthetic concentrations added to the water of transport. No similarities regarding the major compounds of PHEO and PHH were observed. No mortality was observed during the experiments, and PHH did not show any sedative or anesthetic effect. PHEO induced sedation at 250 mg L−1 and deep anesthesia at 500, 750 and 1000 mg L−1. The recovery time increased with increasing concentration of PHEO. There was a significant difference in the time to induce deep anesthesia between PHEO and IC. Water conductivity and mucous cell density were lower in the transport with 50 mg L−1 PHEO. Tambaqui transported with 50 mg L−1 PHEO and 11.6, 17.4, and 23.2 mg L−1 terpinen-04-ol presented lower net whole body K+ and Cl− effluxes. PHEO is an alternative as sedative and anesthetic for tambaqui juveniles, and the concentration of 500 mg L−1 was the best for deep anesthesia. The use of 50 mg L−1 PHEO was effective for the transport of this species because it reduced net K+ and Cl− effluxes and did not stimulate proliferation mucous cells.

International audience

The Yesso scallop Patinopecten yessoensis is one of the most important aquaculture species in Asian countries because of its high economic value, but it has suffered severe infection by Polydora in recent years, causing great economic losses. Polydora mainly parasitizes the left valves of the Yesso scallop, especially the region around the adductor muscle, badly damaging the shell structure and making the shell particularly fragile. To investigate the response mechanism of the Yesso scallop to Polydora, a histological study was performed on healthy and diseased Yesso scallop mantle tissues, which are thought to be responsible for shell formation. In the present study, separate histological and histochemical changes in different mantle regions were detected for the first time. In the diseased scallops, abundant mucous cells containing acid mucopolysaccharides were found in the epidermis of the outer fold, along with a great increase in cilia on the inner epidermis, and a significant increase in mucous cells secreting acid mucopolysaccharides was observed in the middle fold and the central mantle, suggesting an accelerated process of secretion and transportation of shell substances. These changes in the different mantle regions were probably responsible for the repair of different shell layers. The present study provides valuable information for the function of mantle tissue in shell formation and is helpful for genetic breeding of disease-resistant scallops in the future.

We investigated the distribution and morphology of taste organs of the Colorado River toad, Incilius alvarius, in a comparative approach. We also examined whether the age of metamorphosed individuals affected taste disc density and the area of sensory zones. Although taste disc morphology appeared similar to previously studied bufonids, we demonstrateed that taste disc density on the tongue may decrease with age, while the area of taste disc sensory zones may increase. This is consistent with a recent study on a direct developing anuran. Therefore we hypothesize that each individual bears a limited pool of taste organs.

Health diets for Atlantic salmon have become an important component of the integrated pest management strategies targeting sea lice. A challenge trial was performed to examine the effect of supplementing salmon diets with either immunostimulants or essential oils. One control and four experimental diets containing immunostimulants or natural identical extracts were fed to Atlantic salmon in triplicate tanks for 4 weeks before challenging the fish with the sea lice copepodids. Prevalence of infection was 100%, and the mean abundance of infection was 21.2. The lowest mean lice count of 17 per fish (P

Morphology and histochemistry of gill of the abalone, Haliotis discus hannai were described using light microscopy and scanning electron microscopy (SEM). The abalone has bipectinate gill of protobranch. The cilia and microvilli were well-developed on the free surface of the gill filaments. The epithelial layer of gill filament was simple and composed columnar epithelia and mucous cells. Result of AB-PAS (pH 2.5 and 1.0) and AF-AB (pH 2.5) reaction showed that mucous cells contained mainly acidic carboxylated mucosubstances.

BACKGROUND/AIMS Although the gastroprotective properties of Ocimum gratissimum L. have been mentioned, the exact mechanism is yet to be explored. Since acid output plays a significant role in the pathogenesis of gastric ulceration, the present study was aimed at investigating the effect of leaf extract of Ocimum gratissimum on gastric luminal pH, acid output, parietal cell mass and gastric mucous cell population in rabbits. MATERIALS AND METHODS The model of pyloric ligation for acid secretion and ulcer study was employed. Prior to the 4 h ligation, male New Zealand rabbits were treated orally with 75 mg/kg, 150 mg/kg and 250 mg/kg b.w aqueous leaf extract of Ocimum gratissimum twice daily for three weeks. The antisecretory and antiulcer effect of Ocimum gratissimum was compared with omeprazole (20 mg/kg p.o). Parietal cell mass and gastric mucous cell population were determined in the gastric samples by histometry. RESULTS Aqueous leaf extract of Ocimum gratissimum caused significant reduction in ulcer formation, gastric secretion volume and acid output in a dose dependent manner (p

The outer surface of the opercular epidermis (OE) and the epithelium lining the inner surface of the operculum (EISO) ofMacrognathus aculeatum,Colisa fasciataandGlossogobius giuriswas investigated using scanning electron microscopy to unravel their surface ultrastructure. In the fish species investigated, the OE is thick, compared to the EISO. The OE and the EISO remain covered with a mosaic pavement of irregularly polygonal epithelial cells. The free surface of the epithelial cells is thrown into a series of microridges. Modifications in the pattern of microridges could be caused by various intrinsic or extrinsic factors. Interspersed between the epithelial cells in the OE mucous cell pores, mitochondria-rich cells, taste buds and superficial neuromasts could be located. In the EISO, in contrast, taste buds and neuromasts are absent. The modifications in the surface organisations at the OE and EISO in different fish species have been associated to perform a variety of functions and have been discussed in the light of the varied conditions experienced by them.

The present study aimed to illustrate the some histological impact of Dimethoate and Benomyl compounds on the mucous gland and the body wall of Helicella vestalis at 0.25% level after 24 hours post treatment Mucous gland: Tufted tubular and assemble of mucous gland branches were shaped by the effect of 0.25% Dimethoate in mucous gland of H.vestalis after 24 hours post treatment, at the portion time, the amount of mucous exuded decreased with increase in volume of mucous cells. Also, effect of Benomyl in mucous gland were coherence of the branches of the mucous gland vast led to the exsiccation of land snail and its death, and increase in the mucous cell volume with certain change in the color and it had been isolated and had no integration with each other. Effects of Dimethoate on body wall of H.vestalis led to presence of a large apertures resolving on the semblance of leather wide, lessening the amount of mucus excreted, while 0.25% Benomyl clearly showed no apertures on the integrement appearance wide.

The present studies were designed to determine whether our findings in mice showing that the Bcl-2-associated protein X (Bax), which plays a role in the resolution of allergen-induced mucous cell metaplasia, can be applied to asthma in humans. Immunostaining of autopsy tissues from mild and severe asthmatic subjects showed a significant reduction in the percentage of Bax-positive mucous cells compared with those from nonasthmatic controls. To exclude the possibility that postmortem changes may have affected Bax expression, Bax mRNA levels in airway epithelial cells obtained from nonsmoking asthmatic subjects were compared with those from nonasthmatic controls. Because the number of cells obtained by bronchial brushings is limited, we developed a robust preamplification procedure of cDNA before quantitative real-time PCR to allow detection of 100 gene targets from limited sample size, even when it was prepared from partially degraded RNA. cDNA was prepared by reverse transcription from RNA isolated from bronchial epithelial cells obtained by bronchial brushings from well-characterized subjects without lung disease and from subjects with mild asthma. Quantitative analysis showed that Bax mRNA levels were significantly reduced in samples obtained from asthma patients compared with nonasthma controls. Furthermore, Bax mRNA levels were reduced when primary airway epithelial cells from 10 individuals were treated in culture with the T helper 2 cytokine IL-13. These studies show that Bax expression is reduced in airway epithelial cells of even mild asthmatic subjects and suggest that restoring Bax expression may provide a clinical approach for restoring the normal numbers of epithelial cells and reduced mucous hypersecretion in asthma.

Formalin bath treatments of rainbow trout are widely used for control of ectoparasitic infections in fish farms and the effects of this chemical on parasite infections have been studied. In addition, tolerance of the host to various concentrations of formalin are also known. However, effects of formaldehyde on the skin epithelium integrity and mucous cell density still need elucidation. The present study revealed that exposure of rainbow trout fry 2 months post-hatching to various concentrations of formalin affected the mucous cell dynamics of the fish. Limited exposure (50 ppm, 1 h) stimulated mucous cell proliferation as indicated by the slight increase in densities of Alcian blue positive cells in tail fin epidermis. In contrast, high concentrations (200-300 ppm, 1 h) or lengthy exposure (24 h) at lower concentrations caused a decrease in mucous cell density. Scanning electron microscopy revealed effects on the epithelial structure of fish fins. Blebbing of epithelial cell membranes was the first sign of injury. The dilated openings of mucous cells indicated increased release of mucus. Highly irregular organization of the cells followed, with regional differences occurring in different parts of fins. The implications of formalin bathing for susceptibility or resistance of fish to subsequent pathogen exposure are discussed.

Amoebic gill disease (AGD) has been attributed to infection by Neoparamoeba sp. The causal mechanisms for AGD lesion development and the primary pathogenic role of Neoparamoeba sp. require elucidation. Three groups of Atlantic salmon were exposed to viable gill isolated amoebae, to sonicated amoebae, or to sea water containing viable amoebae without direct contact with gill epithelia. Fish were removed 8 days post-exposure and the gills assessed histologically for AGD. AGD occurred only when fish were exposed to viable trophozoites. Consequently, in an accompanying experiment, infection was evaluated histologically at 12, 24 and 48 h post-exposure in three groups of salmon, one group being mechanically injured 12 h prior to exposure. A progressive host response and significant increase (P < 0.001) in the numbers of attached amoebae was apparent over the 48-h duration in undamaged hemibranchs in both treatment groups. There were no significant differences to mucous cell populations. Attachment of Neoparamoeba sp. to damaged gill filaments was significantly reduced (P < 0.05) by 48 h post-exposure. These data further confirm and describe the primary pathogenic role of Neoparamoeba sp. and the early host response in AGD. Preliminary evidence suggests that lesions resulting from physical gill damage are not preferentially colonized by Neoparamoeba sp.

A sharp decrease to

Effect of PCBs on the skin and gill development of olive flounder, Paralichthys olivaceus were investigated by histological methodology and morphometric data. The olive flounder were exposed to limit concentration of effulent of PCBs (3.0 ) for 60 days. Skin development can be classified into four stages: SSEL (simple squamous epithelial layer), MCA (mucous cell appearance) & CCA (club cell appearance) DLA (dermal layer appearance), and SEL (startification of epidermal layer) stages. Gill development had five stages: GFA (gill filament appearance), IGFE (identification of early gill filament epithelial cell) MCA (mucous cell appearance), PCA (pillar cell appearance), and FGL (formation of gill lamella) stages. The periods of structural completion of skin and gill were 22-30 days and 23-30 days after hatching in the exposure group respectively. The process of development of skin and gill of the exposure group was very similar to that of the control group. Therefore, PCBs (3 ) have no influence on the development of skin and gill in the larval stage of olive flounder.

Aims The pathogenesis of intraosseous mucoepidermoid carcinoma (IMEC) remains unknown. Coexistence with odontogenic cysts (ODC) has been reported in 32–48% of IMEC. Furthermore, prosoplastic mucous cells are often seen in the epithelial lining of ODCs. MECT1–MAML2 fusion transcripts have been identified in >66% of salivary gland MEC cases. The aim of this study was to investigate the presence of MAML2 rearrangement in ODCs featuring mucous prosoplasia. Methods and results Ten cases of ODC with a mucous cell component and three cases of IMEC were evaluated using fluorescence in-situ hybridization. All cases occurred in the mandible. The ODCs exhibited a M:F ratio of 4:1 (mean age 49.2 years), while all IMECs occurred in women (mean age 68.3 years). All three IMECs demonstrated MAML2 rearrangement, in 26–61% of tumour cells. Successful hybridization was observed in nine of 10 cases of ODC. In two of these nine, there was MAML2 rearrangement in 12% and 24% of the lining epithelial cells, while three of the nine showed rearrangement in 7–8% of cells; the remaining four cases were negative. Conclusions We identified MAML2 rearrangements in five of nine ODCs lined by mucus-secreting cells. This suggests that at least a subset of ODCs with mucous prosoplasia are characterized by molecular events considered diagnostic for intraosseous and extraosseous MEC.

It has previously been known that the developing parotid glands in humans and rats contain mucous cells in their terminal clusters and acini, but these cells disappear within a short period of time. Using rat parotid glands, IKEDA and AIYAMA (1997, 1999) suggested that the mucous cells might change into serous cells in the early postnatal period, but it is uncertain whether mucous cells appear only in the developing parotid gland of a few species such as humans and rats, or whether the cell transformation actually occurs. To clarify these points, the present study investigated the developing mouse parotid glands. Light microscopy showed cells with secretory granules that stained extensively with PAS and alcian blue in the terminal clusters of a 1-day-old mouse parotid gland. Mucous cell numbers in the terminal clusters and the acini reached a peak on day 5 and decreased on day 7. By day 10, the mucous cells had disappeared altogether. Thus, the presence of mucous cells in the developing mouse parotid gland was confirmed. Electron microscopy showed granules of low electron density and bipartite granules in the mucous cells. Bipartite granules and highly electron-dense granules sometimes co-existed in a single cell. Immuno-electron microscopy revealed a positive reaction for amylase to the low-electron-density granules and the low-electron-density portions of the bipartite granules, in addition to the highly electron-dense granules and the electron-dense cores of the bipartite granules. No mucous cells with nuclei displaying characteristics of apoptosis were recognizable. Lectin histochemistry both at the light and electron microscopic levels showed that the secretory granules in the mouse parotid gland mucous cells had sugar residues similar to those of the mature serous granules. These findings demonstrate that mucous cells appear in the early postnatal mouse parotid gland, and that almost all of these cells may be converted into serous cells.

Observations on the pathology of Ergasilus (Crustacea: Copepoda) from Lake Tanganyika on the gills of Lamprichtys tanganicanus. During a recent survey specimens of Ergasilus sarsi were found on the gills of Lamprichthys tanganicanus. Specimens were fixed intact on the gills and serial sections were made at 5 µm and stained with a trichrome stain. Superficial tissue erosion, fusion of secondary lamella, mucous cell proliferation and Rodlet cells were observed. The prevalence of the parasite was 100% and the number of parasites per host extremely high.

The influence of an acute drop in water temperature on channel catfish ( Ictalurus punctatus ) mucous cell distribution in the epidermis was examined. Channel catfish were subjected to a water temperature drop from 22 to 10° C in 24 h and sampled for histological examination of the epidermis at regular intervals. Three days after the drop in water temperature, there was a marked decrease in the number of mucous cells in the outermost (superficial) portion of the epidermis. The number of mucous cells returned to normal levels after fish were maintained at 10° C for 6 days. If catfish were subjected to the temperature drop and also challenged with Saprolegnia , mucous cells in the superficial epidermis did not recover to normal levels but continued to decline from day 3 until the fish subsequently died from saprolegniasis. These results may explain the dry skin appearance characteristic of catfish exhibiting winter saprolegniasis. Furthermore, since Saprolegnia cysts are normally shed in sloughed mucus, low temperature-induced mucus loss may explain how Saprolegnia cysts attach and infect catfish skin to result in disease. These results also reinforce the notion that an intact external mucus layer is the first line of defence against infectious disease in fish.

Mucous cells were found in the terminal clusters and acini of the parotid gland in early postnatal mice. We examined the development of the parotid gland and histological changes in the properties of the secretory granules of the mucous cells using light and electron microscopy. No mucous cells were recognizable on the day of birth. The cells were observed one day after birth and increased gradually until the 5th day. The granules of the mucous cells showed an intensely positive reaction upon PA-Schiff and alcian blue staining and showed low electron density and a bipartite substructure with a central dense core and a rim of lower density. The central dense core increased gradually from the first day after birth and was entirely digestible with pronase. On and after the 7th day after birth, the mucous cells decreased gradually and disappeared ten days later.These findings suggest that many of the granules in the mucous cells change to serous granules, since mucous cells appear only within a limited period and that the granule cores contain protein and increase in size with development.

We evaluated a possible role for fibrinolytic components in nasal secretion by tissue localization with immunohistochemical techniques and by measuring their antigen concentrations in nasal discharge by means of ELISA and fibrin autography. Nasal mucosa was obtained surgically from the inferior turbinate. Urokinase-type plasminogen activator (u-PA) specific staining was observed in pseudostratified ciliated epithelium and was predominant in mucous cells of the seromucinous gland, while serous cells were almost devoid of stain. The pattern of staining of plasminogen activator inhibitor-2 was similar to that of u-PA. In contrast, plasminogen activator inhibitor-1 (PAI-1) immunoreactive material was localized exclusively in serous cells of seromucinous glands. Positive staining for tissue-type plasminogen activator (t-PA) was observed in endothelial cells and basal cells, which differentiate into either ciliated or goblet cells. Nasal secretions were partially fractionated by immunospecific antibody-immobilized Sepharose. Subsequent fibrin autography patterns indicated the presence of u-PA, PAI-1, and t-PA. After methacholine provocation, the level of t-PA increased transiently but decreased rapidly with subsequent challenges. These differential stainings of fibrinolytic components and the existence of PAs and PAI-1 in the nasal discharge suggest that the fibrinolytic system may play a role in the movement and fluidity of nasal secretion.

The present study was designed to examine the effects of long-term ozone exposure on nasal epithelia and intraepithelial mucosubstances (IM) throughout the nasal airways of F344/N rats. Animals were exposed to 0 (controls), 0.12, 0.5, or 1.0 ppm ozone, 6 h/day, 5 days/wk, for 20 mo. Rats were killed 1 wk after the end of the exposure, and nasal tissues were processed for light and electron microscopy. Standard morphometric techniques were used to determine epithelial cell densities and the amounts of IM in the surface epithelium lining the nasal airways. No mucous cells or IM were present in the epithelia lining the nasal lateral meatus and maxillary sinus of rats exposed to 0 or 0.12 ppm ozone. In contrast, rats exposed to 0.5 or 1.0 ppm ozone had marked mucous cell metaplasia (MCM) with numerous mucous cells and conspicuous amounts of IM in the surface epithelium lining these upper airways. Ozone-induced increases in total epithelial cells (i.e., epithelial hyperplasia) were present only in rats exposed to 1.0 ppm. The results of this study indicate that rats chronically exposed to 1.0 or 0.5 ppm, but not 0.12 ppm, ozone can develop marked MCM with significant increases in IM in both proximal and distal nasal airways. The epithelial changes observed throughout the nasal passages of ozone-exposed rats may be adaptive responses in an attempt to protect the upper and lower respiratory tract from further ozone-induced injury.

This article reviews the use of computerized image analysis and standard morphologic techniques to characterize the responses of nasal epithelium in laboratory rats to single or repeated exposures to a common urban air-pollutant, ozone. Alterations in the number and composition of the epithelial cell populations after either short- or long-term exposures are described. The principal nasal epithelial alteration induced by repeated exposures to this irritating, oxidant pollutant is mucous cell metaplasia (i.e., transformation of airway epithelium, normally devoid of mucous cells, to a secretory epithelium containing numerous mucus-secreting cells). This metaplastic change, induced by acute or chronic ozone exposures, has been morphometrically examined at various times post-exposure. In this article, we describe our current understanding of the pathogenesis and persistence of ozone-induced mucous cell metaplasia in nasal epithelium based on the results of these morphometric studies. Microsc. Res. Tech. 36:276–286, 1997. © 1997 Wiley-Liss, Inc.

The diagnosis of a glandular odontogenic cyst (GOC) on an incisional biopsy continues to remain a diagnostic challenge for the histopathologist. A marker for distinguishing GOC from odontogenic cysts with mucous metaplasia is thus needed in routine pathology practice. This study aimed to determine the histochemical composition of the mucous cells in the GOC and to compare the findings with the mucous cells in odontogenic cysts that show overlapping histomorphological features with the GOC. GOCs (), dentigerous cysts (DCs) (), and radicular cysts (RCs) () with mucous metaplasia were stained using the combined alcian blue(pH 2.5)-PAS histochemical technique. The cysts were evaluated for the frequencies of acidic- (type I), neutral- (type II) and mixed- (acidic and neutral (type III)) mucin containing cells. Significant differences were found between the levels of type I, type II, and type III mucous cells within the 3 cyst types, GOC (), DC (), and RC (), which all showed a predominance of type III mucous cells. There were, however, no significant differences for each mucous cell type between the 3 cyst types. GOC thus appears to share the same histochemical mucin phenotype with the mucous cells in DC and RC.

After acclimation either to high pressure (101 ATA) or to low temperature (9°C), the number of mucous cells within gill epithelium of freshwater eel Anguilla anguilla was significantly decreased and the density of chloride cells was significantly increased when compared to control fish (1 ATA, 19°C).

A skin disease of intensively reared salmonids in Ontario hatcheries, known to the farmers as‘no-mucus skin disease’, is reported for the first time. It was characterized by erosive and ulcerative lesions found mainly on the flanks of fingerlings, which resulted in exposure of the tips of the scales. Associated with these lesions were colonies of bacteria seen in the SEM to be clustered round the mucous cell pores and under-running the margins of epithelial cells. The cause of this condition is unknown, although the response of fish to formalin treatment, and the presence of bacilli seen in skin scrapings and in the SEM, suggest that bacteria are responsible.

Mucous cell metaplasia (MCM) and neutrophil-predominant airway inflammation are pathological features of chronic inflammatory airway diseases. A signature feature of MCM is increased expression of a major respiratory tract mucin, MUC5AC. Neutrophil elastase (NE) upregulates MUC5AC in primary airway epithelial cells by generating reactive oxygen species, and this response is due in part to upregulation of NADPH quinone oxidoreductase 1 (NQO1) activity. Delivery of NE directly to the airway triggers inflammation and MCM and increases synthesis and secretion of MUC5AC protein from airway epithelial cells. We hypothesized that NE-induced MCM is mediated in vivo by NQO1. Male wild-type and Nqo1-null mice (C57BL/6 background) were exposed to human NE (50 μg) or vehicle via oropharyngeal aspiration on days 1, 4, and 7. On days 8 and 11, lung tissues and bronchoalveolar lavage (BAL) samples were obtained and evaluated for MCM, inflammation, and oxidative stress. MCM, inflammation, and production of specific cytokines, granulocyte-macrophage colony-stimulating factor, macrophage inflammatory protein-2, interleukin-4, and interleukin-5 were diminished in NE-treated Nqo1-null mice compared with NE-treated wild-type mice. However, in contrast to the role of NQO1 in vitro, we demonstrate that NE-treated Nqo1-null mice had greater levels of BAL and lung tissue lipid carbonyls and greater BAL iron on day 11, all consistent with increased oxidative stress. NQO1 is required for NE-induced inflammation and MCM. This model system demonstrates that NE-induced MCM directly correlates with inflammation, but not with oxidative stress.

Mucous cell size and distribution were investigated in the skin of five salmon using a novel stereology-based methodology: one (48 cm) fish to test 15 tissue treatment combinations on measures of cell area and density on the dorsolateral region and, using the most suitable treatment, we mapped mucous cell differences between body regions on four (52 cm) salmon, comprising a male and a female on each of two diets. The section site, decalcification, embedding medium and plane of sectioning all impacted significantly on mucous cell size, whereas mucous cell density is more robust. There were highly significant differences in both mucosal density and mean mucous cell size depending on body site: the dorsolateral skin of the four salmon had significantly denser (about 8% of skin area) and larger (mean about 160 μm(2)) mucous cells, whereas the lowest mean density (about 4%) and smallest mean area (115 μm(2)) were found on the head. We found that 100 random measurements may be sufficient to distinguish differences >7 μm(2) in mean mucous cell areas. The results further suggest that salmon exhibit a dynamic repeatable pattern of mucous cell development influenced by sex, diet and possibly strain and season.

A couple of triple and dual staining methods [high iron diamine (HID)-alcian blue (AB) pH 2.5-periodic acid-Schiff (PAS) and HID-PAS] were successfully utilized to analyze mucosubstances elaborated and released by epidermal mucous cells of four Indian freshwater fish species in light microscopy. In addition, other single and dual staining methods such as PAS, HID, AB pH 1.0, AB pH 2.5, AB pH 1.0-PAS, AB pH 2.5-PAS and HID-AB pH 2.5 were employed to further analyze the same substances and to substantiate the results obtained by the HID-AB pH 2.5-PAS and HID-PAS techniques. The comprehensive uses of pre-lectin histochemical procedures including the HID-AB pH 2.5-PAS and HID-PAS methods were unusually useful to study the cytochemical properties of mucosubstances of different mucous cell types involved in the epidermis of four Indian freshwater fish species.

airway remodeling during chronic inflammatory disease processes such as asthma and chronic obstructive pulmonary disease involves a variety of morphological changes, including mucous cell metaplasia and airway fibrosis. Over the past several years, an intense effort has been aimed at elucidating the

We estimated the proliferative activity of serous and mucous acinar cells in mixed-type salivary glands of sucking Mongolian gerbils, using immunohistochemistry with proliferating cell nuclear antigen (PCNA) and in vivo labeling of S-phase cells with the thymidine analog bromodeoxyuridine (BrdU). In both sublingual and Weber's (postlingual) salivary glands, acinar secretory cells showing immunoreactivity for anti-PCNA and anti-BrdU were restricted to serous-type cells that were also positive for a serous component, lysozyme. Some less-differentiated cells found in the serous demilunes or acini, which were negative for lysozyme, also showed proliferative activity, while mucous-type cells never did. These results suggest that in the histogenesis of the mixed gland endpieces, the serous-type cells include immature, differentiating cells, while the mucous-type cells consist of only mature, well-differentiated cells., Acta Histochemica et Cytochemica, 35(4), pp.343-345; 2002