Search

We analysed the embryonic epidermis of the pool frog, Pelophylax lessonae, by light and electron microscopy techniques, and characterized preliminarily its mucous secretions with conventional histochemistry (Toluidine Blue, Periodic Acid-Schiff, Alcian blue pH 2.5 and Alcian blue pH 1.0). At Gosner’s developmental stage 21, the epidermis consisted of a bilayered epithelium with five cell types. Basal cells (BCs) constituted the basal layer, presented a large nucleus and were sometimes observed in mitosis. Ciliated cells (CCs) had a ciliated apical membrane, with carboxylated glycans in the sub-apical portion. TEM analysis revealed small vesicles just below the surface, a central nucleus, and evident yolk plates. Goblet cells (GCs) and small secretory cells (SSCs) showed secreting vesicles and vacuoles, respectively. In the mucus secretion of GCs sialosulphomucins appeared, while in that of SSCs sulphation was not observed. Under TEM, GCs had irregular shaped nuclei and a less electron-dense cytoplasm with respect to SSCs. Ionocytes (INs) presented apical microvilli and a high electron-dense cytoplasm with vacuoles. SEM analysis revealed that GCs outnumbered the other cell types and that SSCs and INs were usually located together near to GCs. The relatively simple structure of the epidermis and its direct interfacing with the environment renders it a good model for the study of structure and development of mucociliary epithelia, as well as of its alterations in the presence of toxicants.

AbstractAn in situ analysis of mucin secretions along the annual cycle was performed on the striped Venus clam, Chamelea gallina. Individuals of both sexes from an exploited stock of Margherita di Savoia (Southern Adriatic Sea, Central Mediterranean Sea) were made in June 2020 and 2021, and in January 2021 and 2022, representative of summer and winter seasons, respectively. Tissues from the foot and the gills were analyzed for histochemical and lectin-histochemical analyses. Staining with Periodic Acid-Schiff, Alcian Blue pH 2.5 and High-Iron-Diamine indicated that mucins from both the foot and the gills were acidic, mostly sulfated. Lectin-binding analyses with PNA, SBA, WGA, LTA, UEA-I, AAA, SNA, MAA-II and ConA indicated the presence of N-acetyl-glycosaminylated, mannosylated and fucosylated residuals in the saccharidic chains. In the gills, the amount of acidic and glycosaminylated residuals was higher in summer in both sexes, whereas fucosylation was similar along the sampling period and mannosylation was never observed. In the foot, both surface epithelial and subepidermal secreting cells increased sulfation in winter in males, but not in females. Glycosaminylation and fucosylation were observed only in the surface cells of males. Mannosylated residuals were observed in all the foot cell types in both sexes. It is hypothesized that the observed qualitative and quantitative variations in mucin secretion is linked to the reproductive cycle.

Seasonal variation of liver glycogen, lipids and melanomacrophages were investigated in a non-hibernating population of Pelophylax kl. esculentus from Calabria by histochemical methods and computer-assisted image analysis. Twenty individuals of both sexes were sampled in a tank in Roseto Capo Spulico (Cosenza, Calabria) in four periods of the year 2016 (February, May, July, October). Portions of liver from each individual were included in paraffin for glycogen and melanomacrophages, and epoxydic resin-araldite for lipid analysis. Sections were stained with periodic acid-Schiff (PAS) for glycogen (with diastase-PAS as control) or osmium-tetroxide for lipids, or left unstained for melanomacrophages (appearing naturally black due to melanin). Image analyses were performed on 9–12 grayscale converted pictures per individual. Total areas per µm2 of glycogen, lipids and melanomacrophages, as well as counts of lipid droplets and melanomacrophages and mean area of single lipid droplets and melanomacrophages, were measured. Statistical analyses were performed by analysis of variance (ANOVA) with bootstrap resampling. Significant variation among sampling periods was found for each variable. Glycogen and lipids co-vary, with higher values observed in October–February and lower values in May–July, whereas melanomacrophages reach a peak in May and have much lower values in the other months. It is concluded that, in the absence of a hibernating period, reproduction is the main force regulating the annual cycles of reserve storing and melanin production.

Aquaporins (AQPs) are important for water transport in the gastrointestinal tract. Changes in their expression and/or localization could cause in disorders and be used as therapeutic targets. Aquaporin-4 (AQP4) is expressed predominantly on the basolateral membrane of the parietal cells in the corpus of the murine gastric glands. Although the secretion of gastric juice is not affected in AQP4-deficient knockout, we evaluated by light microscopy whether the lack of AQP4 affects the glycopatterns of secreting gastric cells. Wild type (WT) and AQP4-deficient knockout mice (KO) were fed a standard diet ad libitum before sacrifice. Segments of stomach corpus were collected, fixed in buffered formalin, and embedded in paraffin wax. Sections, 5-μm thick, were analyzed by histochemical methods (Periodic acid-Schiff, Alcian Blue pH 2.5), and binding of lectins specific to GalNAc (SBA, DBA), Gal (PNA) GlcNAc (WGA, GSAII) mannose and/or glucose (ConA), and fucose (UEA-I, AAA, LTA). Immunohistochemical methods such as anti-Muc6 for neck cells and anti- β- H + /K + -ATPase for parietal cells were also performed. Compared to WT mice, in the mucous cells of KO lower amounts of glycans with galactosyl/galactosaminylated, glycosyl/glycosaminylated, and fucosylated residues were observed; lower fucosylation resulted also in the parietal cells. The observed differences of KO in respect to WT could lead to severer pathological conditions. RESEARCH HIGHLIGHTS: Glycopatterns in gastric glands were compared between wild type (WT) and AQP4-deficient knockout (KO) mice by histochemical and lectin-binding methods. In the mucous cells of KO lower amounts of glycans with galactosyl/galactosaminylated, glycosyl/glycosaminylated and fucosylated residues were observed. In the parietal cells lower fucosylation also resulted. AQP4-deficiency affects glycosylation and could result in altered functionality and pathological conditions., (© 2024 Wiley Periodicals LLC.)

Aluminum (Al) is used in everyday life and present in food drugs, packaging, industry, and agriculture. Although it is the most common metal in the Earth crust, a correlation has been demonstrated between its presence and various pathologies, even serious ones, especially of a neurological type. However, there is a histological gap regarding the role Al can have in contact with the covering and secreting epithelia. The alterations of the ventral and dorsal foot mucocytes and their secretions of the snail Eobania vermiculata caused by Al were investigated in situ by histochemical and lectin-histochemical techniques. Administration to different experimental groups took place for 3 and 9 days with 50 and 200 μM of AlCl 3 . Several types of mucocytes were detected with a prevalent secretion of acid glycans in the foot of E. vermiculata. Sulfated glycans prevail in the dorsal region, with one type showing only fucosylated residues and another also having galactosaminylated and glycosaminylated residues. Carboxylated glycans prevail in the ventral region, with presence of galactosaminylated, glycosaminylated, and fucosylated residuals in both cells. Snails treated presented a general decrease of mucin amount in the secreting cells and affected the mucus composition. These changes could alter the rheological and functional properties of the mucus with possible implications for the health of the treated animals. RESEARCH HIGHLIGHTS: Snails were fed with Al-contaminated lettuce at different concentrations. In the foot mucocytes produced mucus with prevailing acidic glycans. In the treated resulted a reduction in the amount of mucus and an alteration of glycan composition., (© 2024 Wiley Periodicals LLC.)

Background: Urothelium is a multilayer epithelium covering the inner surface of the urinary bladder that acts as a blood-urine barrier and is involved in maintaining the wellbeing of the whole organism. Glycans serve in the maturation and differentiation of cells and thus play a key role in the morphology and function of the multilayered epithelium. The aim of the present study was to examine the glycoprotein pattern of the horse urinary bladder urothelium by lectin histochemistry., Methods: The study involved urinary bladders from four horse stallions. Tissue sections were stained with a panel of eleven lectins, in combination with saponification and sialidase digestion (Ks)., Results: Basal cells displayed high-mannose N-glycans (Con A), α2,6-linked sialic acid (SNA), and O-linked sialoglycans with sialic acids linked to Galβl,3GalNAc (T antigen) (KsPNA) and terminal N-acetylgalactosamine (Tn antigen) (KsSBA). The young intermediate cells expressed terminal N-acetylglucosamine (GlcNAc) (GSA II), galactose (GSA I-B 4 ), T- and Tn antigens (PNA, SBA). The mature intermediate cells showed additional high-mannose N-glycans, O-linked sialoglycans (sialyl-T antigen, sialyl-Tn antigen), α2,6- and α2,3-linked sialic acid (MAL II), α1,2-linked fucose (UEA I), and GlcNAc (KsWGA). The latter residue marked the boundary with the overlying surface layer. Few Con A positive intermediate cells were seen to cross the entire urothelium thickness. The surface cells showed additional glycans such as T antigen and sialic acids linked to GalNAc binding DBA (KsDBA). Few surface cells contained α1,3-linked fucose (LTA), whereas some other cells displayed intraluminal secretion of mucin-type glycans terminating with GalNAcα1,3(LFucα1,2)Galβ1,3/4GlcNAcβ1 (DBA). The luminal surface expressed the most complex glycan pattern in the urothelium because only α1,3-linked fucose lacked among the demonstrated glycans., Conclusions: This study showed that the glycan pattern becomes more complex from the basal to surface layer of the urothelium and that surface cells could modify the composition of urine via the secretion of glycoproteins., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier GmbH. All rights reserved.)

Background: The reproductive cycle of the recently described sponge Tethya meloni was investigated for a period of 15 months (September 2018 - November 2019) in the Mar Piccolo of Taranto (Southern Italy) and was compared with data previously collected for the other two sympatric species of the same genus known for Mediterranean Sea, T. citrina and T. aurantium., Results: T. meloni is a gonochoric species with a sex ratio strongly shifted towards females. Asexual budding was a seasonal process, limited to few specimens. In a specimen collected in September 2018 both oocytes and buds occurred, suggesting that in T. meloni the sexual and asexual phases may coexist both at the population and individual levels., Conclusions: The data obtained from this research compared with the available literature confirm the high temporal variability of the reproductive cycles in the Mediterranean species of Tethya, but with common general characteristics. In sexual reproduction, the oocyte production period lasts several months, with a peak between summer and autumn while spermatogenesis, shorter but with greater reproductive effort, follows the onset of oogenesis. The asexual reproduction phase of T. meloni, on the other hand, occurs in a short period and seems to have less importance in the overall reproductive process., (© 2022. The Author(s).)

Gene therapy has become an important approach for treating cancer, and electroporation represents a technology for introducing therapeutic genes into a cell. An example of cancer gene therapy relying on gene electrotransfer is the use of immunomodulatory cytokines, such as interleukin 2 (IL-2) and 12 (IL-12), which directly stimulate immune cells at the tumour site. The aim of our study was to determine the effects of gene electrotransfer with two plasmids encoding IL-2 and IL-12 in vitro and in vivo. Two different pulse protocols, known as EP1 (600 V/cm, 5 ms, 1 Hz, 8 pulses) and EP2 (1300 V/cm, 100 µs, 1 Hz, 8 pulses), were assessed in vitro for application in subsequent in vivo experiments. In the in vivo experiment, gene electrotransfer of pIL-2 and pIL-12 using the EP1 protocol was performed in B16.F10 murine melanoma. Combined treatment of tumours using pIL2 and pIL12 induced significant tumour growth delay and 71% complete tumour regression. Furthermore, in tumours coexpressing IL-2 and IL-12, increased accumulation of dendritic cells and M1 macrophages was obtained along with the activation of proinflammatory signals, resulting in CD4 + and CD8 + T-lymphocyte recruitment and immune memory development in the mice. In conclusion, we demonstrated high antitumour efficacy of combined IL-2 and IL-12 gene electrotransfer protocols in low-immunogenicity murine B16.F10 melanoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Mitochondria are subcellular organelles involved in cell metabolism and cell life-cycle. Their role in apoptosis regulation makes them an interesting target of new drugs for dealing with cancer or rare diseases. Several peptides and proteins isolated from animal and plant sources are known for their therapeutic properties and have been tested on cancer cell-lines and xenograft murine models, highlighting their ability in inducing cell-death by triggering mitochondrial apoptosis. Some of those molecules have been even approved as drugs. Conversely, many other bioactive compounds are still under investigation for their proapoptotic properties. In this review we report about a group of peptides, isolated from animal venoms, with potential therapeutic properties related to their ability in triggering mitochondrial apoptosis. This class of compounds is known with different names, such as mitochondriotoxins or mitocans., (Copyright © 2020 Elsevier B.V. All rights reserved.)

High-fat diet (HFD) alters the glycosylation patterns of intestinal mucins leading to several health problems. We studied by histochemical and lectin-binding methods mucin alterations in the duodenum of mice fed a HFD for 25 weeks. Histochemical methods included periodic acid-Schiff, alcian blue pH 2.5, and high-iron diamine. Lectin-binding experiments were performed with SBA, PNA, WGA, MAA-II, SNA, ConA, UEA-I, LTA, and AAA. SBA, PNA, WGA, MAA-II, and SNA were tested also after desulfation and ConA after periodate-sodium borohydrate treatments (paradoxical ConA). Duodenal mucins are secreted by Brunner's glands and goblet cells in the villi. Brunner's glands of HFD mice showed increased secreting activity and a general reduction of glycosylated residuals, such as fucose and terminal α1,4-linked GlcNAc. Moreover, a general reduction of glycosylated residuals in the goblet cells of villi such as the fucosylated and sulfated ones was observed. Since the cited residuals are involved in cytoprotective and cytostatic functions, as well as in interactions with the intestinal microbiota and protection against parasites and inflammatory disorders, we conclude that HFD can predispose duodenum to several possible health disorders.

Ovarian cancer (OC) is the most lethal gynecologic cancer characterized by an elevated apoptosis resistance that, potentially, leads to chemo-resistance in the recurrent disease. Mitochondrial oxidative phosphorylation was found altered in OC, and mitochondria were proposed as a target for therapy. Molecular evidence suggests that the deregulation of mitochondrial biogenesis, morphology, dynamics, and apoptosis is involved in carcinogenesis. However, these mitochondrial processes remain to be investigated in OC. Eighteen controls and 16 OC tissues (serous and mucinous) were collected. Enzymatic activities were performed spectrophotometrically, mitochondrial DNA (mtDNA) content was measured by real-time-PCR, protein levels were determined by Western blotting, and mitochondrial number and structure were measured by electron microscopy. Statistical analysis was performed using Student's t -test, Mann-Whitney U test, and principal component analysis (PCA). We found, in OC, that increased mitochondrial number associated with increased peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) and mitochondrial transcription factor A (TFAM) protein levels, as well as mtDNA content. The OC mitochondria presented an increased maximum length, as well as reduced cristae width and junction diameter, associated with increased optic atrophy 1 protein (OPA1) and prohibitin 2 (PHB2) protein levels. In addition, in OC tissues, augmented cAMP and sirtuin 3 (SIRT3) protein levels were observed. PCA of the 25 analyzed biochemical parameters classified OC patients in a distinct group from controls. We highlight a "mitochondrial signature" in OC that could result from cooperation of the cAMP pathway with the SIRT3, OPA1, and PHB2 proteins.

The localization of intestinal glycoconjugates of the blunthead pufferfish Sphoeroides pachygaster and the grey triggerfish Balistes capriscus from the north-western Ionian Sea was analysed by histochemical methods (PAS, AB pH 2.5, HID) and lectin binding experiments (WGA, LFA, SBA, sialidase-SBA, PNA, sialidase-PNA, ConA, AAA, UEA-I, LTA) to assess how evolutionary loss of a functional stomach in S. pachygaster affects intestinal secretions relative to the B. capriscus, which retains the plesiomorphic gastric condition. Sphoeroides pachygaster had a lower content of acid mucins but more complex sialylation patterns than B. capriscus. GalNAc and GlcNAc residuals were present in both, but GalNAc residuals in S. pachygaster were subterminal to sialic acid. Balistes capriscus lacked galactosylated residuals and its enterocytes had a glycocalyx that differed in composition between the small intestine and the rectum and was missing from S. pachygaster. Functional and ecological implications of these findings are discussed., (© 2018 The Fisheries Society of the British Isles.)

Factor XIIIA (FXIIIA) levels are independent predictors of early prognosis after acute myocardial infarction (AMI) and the Valine-to-Leucine (V34L) single nucleotide polymorphism (SNP) seems associated with lower AMI risk. Since the long-term AMI prognosis merits deeper investigation, we performed an observational study evaluating relationships between FXIIIA residual levels, cardiovascular risk-factors, and inherited genetic predispositions. FXIIIA V34L was genotyped in 333 AMI patients and a five-year follow-up was performed. FXIIIA levels assessed at day-zero (d0) and four days after AMI (d4), and conventional risk factors were analyzed, focusing on the development of major adverse cardiovascular events (MACE). FXIIIA assessed at d0 and d4 was also an independent MACE predictor in the long-term follow-up (FXIIIA d0 , Odds Ratio (OR) = 3.02, 1.79⁻5.1, p = 0.013; FXIIIA d4 , OR = 4.46, 2.33⁻8.55, p = 0.0001). FXIIIA d4 showed the strongest MACE association, suggesting that the FXIIIA protective role is maximized when high levels are maintained for longer time. Conversely, FXIIIA levels stratified by V34L predicted MACE at a lesser extent among L34-carriers (Hazard Risk (HR) VV34 = 3.89, 2.19⁻6.87, p = 0.000003; HR L34-carriers = 2.78, 1.39⁻5.57, p = 0.0039), and V34L did not predict all MACE, only multiple-MACE occurrence ( p = 0.0087). Finally, in survival analysis, heart failure and death differed significantly from stroke and recurrent ischemia ( p = 0.0013), with FXIIIA levels appreciably lower in the former ( p = 0.05). Overall, genetically-determined FXIIIA levels have a significant long-term prognostic role, suggesting that a pharmacogenetics approach might help to select those AMI patients at risk of poor prognosis in the need of dedicated treatments.

Kotschy's Gecko, Mediodactylus kotschyi, is a small gecko native to southeastern Europe and the Levant. It displays great morphological variation with a large number of morphologically recognized subspecies. However, it has been suggested that it constitutes a species complex of several yet unrecognized species. In this study, we used multilocus sequence data (three mitochondrial and three nuclear gene fragments) to estimate the phylogenetic relationships of 174 specimens from 129 sampling localities, covering a substantial part of the distribution range of the species. Our results revealed high genetic diversity of M. kotschyi populations and contributed to our knowledge about the phylogenetic relationships and the estimation of the divergence times between them. Diversification within M. kotschyi began approximately 15 million years ago (Mya) in the Middle Miocene, whereas the diversification within most of the major clades have been occurred in the last 5 Mya. Species delimitation analysis suggests there exists five species within the complex, and we propose to tentatively recognize the following taxa as full species: M. kotschyi (mainland Balkans, most of Aegean islands, and Italy), M. orientalis (Levant, Cyprus, southern Anatolia, and south-eastern Aegean islands), M. danilewskii (Black Sea region and south-western Anatolia), M. bartoni (Crete), and M. oertzeni (southern Dodecanese Islands). This newly recognized diversity underlines the complex biogeographical history of the Eastern Mediterranean region., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Frailty has become a high-priority issue in cardiovascular medicine because of the aging of cardiovascular patients. Simple and reproducible tools to assess frailty in elderly patients are clearly on demand. Their application may help physicians in the selection of invasive and medical treatments and in the timing and modality of the follow-up. The frailty in elderly patients receiving cardiac interventional procedures (FRASER) program is designed with the aim to validate the use of the short physical performance battery (SPPB) as prognostic tools in patients admitted to hospital for acute coronary syndrome (ACS)., Methods: The FRASER program is a multicenter prospective study involving 4 Italian cardiology units. The FRASER program enrolls only patients aged ≥70 years. The core of the FRASER program includes patients admitted to hospital for ACS. The aims are (1) to describe SPPB distribution before hospital discharge and (2) to investigate the prognostic role of SPPB score. The primary outcome is a composite of 1-year all-cause mortality and hospital readmission for any cause. Ancillary analyses will be focused on different study populations (patients hospitalized for arrhythmias or acute heart failure or symptomatic severe aortic stenosis) and on different tools to assess frailty (multidimensional prognostic index, clinical frailty score, grip strength)., Discussion: The FRASER program will fill critical gaps in the knowledge regarding the link between frailty, cardiovascular disease, interventional procedures and outcome and will help physicians in the generation of a more personalized risk assessment and in the identification of potential targets for interventions.

The secretion of the goblet cells in the intestine of Trachemys scripta elegans was studied in situ by histochemical methods to analyze the diversity of sugar chains, with particular regard to the acidic glycans. Conventional histochemical stains (Periodic acid-Schiff, Alcian Blue pH 2.5, High Iron Diamine) and binding with ten FITC-labelled lectins combined with chemical and enzymatic pre-treatments were used to characterize the oligosaccharidic chains. The intestine can be divided into three regions, i.e. a duodenum, a small intestine and a large intestine. Goblet cells were observed in all the three tracts and presented an acidic secretion. WGA, LFA, PNA and SBA binding was observed only after desulfation. Glycans secreted by the three tracts consist mainly of sulfosialomucins with 1,2-linked fucose, mannosylated, glucosaminylated and subterminal galactosyl/galactosaminylated residuals. Differences among tracts are quantitative rather than qualitative, with sulfated, galactosaminylated and glycosaminylated residuals increasing from duodenum to large intestine, and galactosylated and fucosylated residuals showing an opposite trend. Variation is observed also between apices and bases of villi in both duodenum and small intestine, where sulphation decreases from the base to the apex and glycosylation shows an opposite trend. Functional implication of these findings is discussed in a comparative context., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The Octopus vulgaris farming is impaired by the high mortality of the paralarvae during the first month of life. Several factors have been investigated in this regard, but no data exist on the body surface mucus, which represents the interface with the outside environment. This study included morphometric analysis and glycoconjugates characterization of skin mucus in reared Octopus vulgaris paralarvae during the first month of life. Four types of mucous cells were distinguished:  mucous 1 (m1) and mucous 2 (m2) cells were scattered in the mantle epidermis, mucous 3 (m3) and mucous 4 (m4) in the epithelium surrounding the sucker. Except for the presence of fucosylated and neutral glycoconjugates in all mucous cells, each cell type expressed a characteristic glycopattern. m2 and m4 contained also suphate and acid non-sulphate glycans, m3 lacked suphate glycoproteins. Lectin histochemistry showed that mantle mucous cells (m1, m2) expressed GlcNAc and lactosamine terminating glycans. m2 also contained GalNAc terminal or penultimate to sialic acid. m3 was distinguished by mannosylated glycans terminating with lactosamine and m4 by α2,6 sialoglycans. Glycoproteins terminating with lactosamine, Galβ1,3GalNAc, and α1,6-linked fucose were a common feature of paralarvae surface layer. Morphometry revealed a significant decrease of m1 and m2 abundance during the first month of life, afterwards the reared paralarvae died. Since the glycopattern did not change during the investigated period, the mantle mucous cells abundance could be related to the Octopus vulgaris paralarvae survival.

Intracellular glycans in the urothelium of urinary bladder of 10 adult male Landrace pigs were characterized in situ by immunohistochemical detection of Muc1 mucin by anti MUC1 from rabbit, conventional histochemical techniques (Periodic-Acid Schiff, Alcian Blue pH 2.5, High-Iron Diamine), and binding with 13 lectins (PNA, DBA, RCA-I, WGA, SBA, BSI-B4, ConA, AAA, UEA-I, LTA, LFA, MAA-II, SNA) combined with chemical and enzymatic pre-treatments (β-elimination, desulfation and neuraminidase) to gather reference data for this model animal. Muc1 mucin was detected in the secreting granules of superficial cells and the underlying layer of intermediate cells. The secreting granules in both intermediate cells and superficial cells were rich in carbohydrates, with the oligosaccharidic chains mostly O-linked to proteins. Glycoproteins were prevailing over glycosaminoglycans (GAGs). In both superficial and intermediate cells sulfated and/or sialylated glycans were present, sulfation decreasing in the deeper layers. Lectin-binding detected presence of terminal sialic acid linked mostly in α2,6 to GalNAc, Gal terminal or subterminal to sulfates, GalNAc, GlcNAc, and Fuc, mostly linked in α1,6, α1,3 α1,4 and α1,2 to GlcNAc or Gal, but not to lactosamine chains. Except for fucosylation, the oligosaccharidic chains in the glycoproteins of the urothelium of pig urinary bladder were similar to those linked to human MUC1, which is fundamental in cell adhesion and immunological processes in the urothelium. The co-distribution of Muc1 and saccharidic residues suggests that many of them are linked to the glycoprotein., (© 2016 Wiley Periodicals, Inc.)

The mucins secreted by the Brunner's glands and the duodenal goblet cells of the Guinea-pig and the house mouse were compared by conventional and FITC-conjugated lectin histochemistry. Methylation/saponification and sialidase digestion were performed prior to lectin binding to detect the residues subterminal to sulfated groups and sialic acid, respectively. In the Guinea-pig the Brunner's glands produce class-III stable sulfosialomucins. Sialic acid is mostly 2,6-linked to galactose or to N-acetylgalactosamine and is in part O-acetylated in C7, C8, and C9. Sulfated groups are probably linked to sialic acid and N-acetylgalactosamine. Terminal residuals of N-acetylglucosamine, galactose, N-acetylgalactosamine and fucose linked in α1,2, α1,3, and α1,4 are also present. Duodenal goblet cells of the Guinea-pig present a lower number of residuals in respect to the Brunner's glandular ones, with sialic acid and N-acetylgalactosamine subterminal to sulfated groups. In the house mouse the Brunner's glands produce class-III stable neutral mucins, binding to same lectins as in the Guinea-pig except for those specific to sialic acid. A diversity of fucosylated residuals higher than in the Guinea-pig is observed. The mouse duodenal goblet cells lack stable class-III mucins, have little sialic acid and present a lower number of residuals in respect to the correspondent Brunner's glands. Regulation of the acidic intestinal microenvironment, prevention of pathologies and hosting of microflora can explain the observed results and the differences observed between the two rodents., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

The extra-cellular matrix of fertilized eggs in the bufonid toads Bufo bufo and Bufotes balearicus was studied to clear the relationships between structural and molecular diversity. Histochemical (PAS, AB pH 2.5 and pH 1.0, Beta-elimination PAS) and lectin-histochemical (Con A, WGA, Succinyl-WGA, PNA, RCA-1, DBA, SBA, AAA, UEA-I, LTA) techniques were used and the observations were made under light and electron microscopy. Both species present a fertilization envelope (FE) and two jelly layers (J1 and J2). The fibers of J2 are shared among the eggs of a clutch in a jelly ribbon. The FE of both species presents neutral glycoproteins, mostly N-linked. In B. bufo there are also residuals of mannose and/or glucose and N-acetylglucosamine. In the FE fibers run parallel to egg's surface or are in bundles or looser hanks with no clear orientation. The J1 layer of both species presents sialosulfoglycoproteins, mostly O-linked, with lactosaminylated, galactosaminylated, glycosaminylated, and fucosylated residuals. A lower amount of galactosaminylated residuals is observed in B. balearicus in respect to B. bufo, whereas the opposite is seen in the amount of fucosylated residuals. The J2 layer is similar in composition to J1 but in B. balearicus there are no glucosaminylated residuals. J layers present fibers and granules that reduce towards J2 . Several microorganisms, in particular blue algae, are observed in the J2 layer of both species. In respect to other species, B. bufo and B. balearicus have a lower number of jelly layers, but a comparable number of glycan types., (© 2014 Wiley Periodicals, Inc.)

Glycoconjugates secreted by the pedal system of the rayed limpet, Patella caerulea, were characterised in situ by histochemical and lectin-histochemical methods in individuals collected around the annual cycle, in November, March, and June. Stainings with periodic acid-Schiff (PAS), Alcian blue pH 2.5 (AB pH 2.5), Alcian blue pH 1.0 (AB pH 1.0), high-iron diamine-Alcian blue pH 2.5 and lectin binding assays with 9 lectins (Con A, WGA, succinylated-WGA, PNA, DBA, SBA, AAA, UEA-I, LTA) were performed. Four secreting cell types were observed in the sole, one in the peripheric region, and two in the sidewall. Glycoconjugate composition varied among cell types and also in one and the same cell type throughout the year. β-Elimination followed by PAS and AB pH 2.5 stainings indicated that most saccharidic chains were O-linked to the protein backbone. Secretion by sole and peripheric region was acidic, carboxylated and/or sulfated, whereas that of the sidewall was neutral. Glucosaminylated and 1,4-fucosylated residuals were predominant in the cell types along the year, 1,2-fucosylated residuals being observed only in the sidewall cells in June. Mannosylated and/or glycosylated residuals were observed in all cells mostly in November. Galactosylated/galactosaminylated residuals were present mostly in the sidewall cells and in the sole subepidermal mucocytes in June. Mannosylated and/or glycosylated residuals in November are probably linked to gonad maturation or to higher locomotion and foraging activity, whereas galactosaminylation in the sole cells and 1,2-fucosylation and glucosaminylation in the sidewall cells in June are linked to a prolonged stationary state, increasing water adsorption to counteract dehydration and/or to modulate microbial interactions., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

The characterization of mucus O-linked glycans in the proximal and distal mouse colon was performed by conventional histochemical methods and by lectin histochemistry in combination with enzymatic treatment (PNGase, α1,2 fucosidase, sialidase digestion), with and without prior desulfation. We demonstrated the presence of sialo- and sulfomucins in both the proximal and distal colon of the mouse. In the distal colon the sulfomucins were clearly prevalent, although there were always sialomucins with sialyl residues linked α2,6 to the subterminal galactose. Sialic acid was poorly O-acetylated, especially in the distal colon. The lectin binding pattern indicates a massive presence of fucose α1,2 linked to galactose in O-glycans and smaller quantities of fucose linked α1,6 to N-acetylglucosamine in the core of N-linked glycans. Lectin histochemistry also demonstrated the presence of glycosidic residues of N-acetylglucosamine, N-acetylgalactosamine, and galactose in oligosaccharide chains of highly sulfated mucins., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

Objective: To verify the ultrafine conformation of term villi in diabetic and normal placentae. Villar dysmaturity and chorangiosis are considered the most frequent findings in diabetic placentae, but their histogenesis is still unclear., Study Design: We performed a morphometric study of 38 term villi in 5 diabetic placentae and of 37 term villi of 5 normal placentae in order to know the different extension of endothelial surface (VL), the maximum (D max) and minimum (D min) distance of the vessels from the basal membrane, as well as the exact thickness of basal membrane (MT BM). The villi were examined with transmission electron microscopy, and parameters were automatically acquired with the iTEM software (Soft Imaging System, Münster, Germany)., Results: VL results were statistically higher in diabetic placentae than in normal ones. Also D max and D min were higher in diabetic disease. MT BM was not different in the two groups., Conclusion: Our findings show that, in the presence of chorangiosis, the vessel surface in diabetic placentae is higher than in normal group, but the vessels are randomly distributed in term villi. The basal membrane is not different in the two groups. Morphometric evaluation seems to be more accurate using ultrafine samples.

Characterization of mucins in the alimentary tract of the grass snake, Natrix natrix was performed by histochemical (PAS, Alcian Blue, pH 2.5 and pH 1.0, sialidase-Alcian Blue, pH 2.5, HID-AB pH 2.5) and lectin-histochemical (WGA, SWGA, PNA, sialidase-PNA, SBA, sialidase-SBA, DBA, sialidase-DBA, ConA, BSI-B4, AAA, UEA-1, LTA) techniques. Oesophageal lining epithelium consisted of ciliated and goblet cells, with no pluricellular glands. Mannosylated sialosulfomucins were observed. Fundic mucosa of stomach presented surface cells producing sialomucins with terminal sialic acid linked to galactose. In gastric glands neck and oxynticopeptic cells were found. Neck cells had sialomucins with mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine and fucose-α-(1,2)-linked residues. Cytoplasm of oxynticopeptic cells showed N-acetylgalactosamine and fucose residues. Secretion of surface cells in pyloric mucosa was similar to that of fundic ones, differing in having fucose. Goblet cells in the small intestine of N. natrix produced sulfo- and sialomucins, with sialic acid linked to galactose and N-acetylgalactosamine residues. Mucins also presented residues of mannose. Goblet cells in the large intestine presented sulfomucins only, with terminal N-acetylgalactosamine, galactose and N-acetylglucosamine. The glycosylation patterns found are probably related to protection against injuries, gastric juice and microorganisms, both pathogenic and decomposers, as well as to dietary adaptations., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

We studied the glycopatterns and ultrastructure of the extra-cellular matrix (ECM) of the egg of the Apennine yellow-bellied toad Bombina pachypus, by light and electron microscopy in order to determine structure, chemical composition and function. Histochemical techniques in light microscopy included PAS and Alcian Blue pH 2.5 and 1.0, performed also after β-elimination. Lectin-binding was tested with nine lectins (AAA, ConA, DBA, HPA, LTA, PNA, SBA, UEA-I, WGA). An inner fertilization envelope (FE) and five jelly layers (J1-J5) were observed, differing in histochemical staining, lectin binding and ultrastructure. Most glycans were O-linked, with many glucosamylated and fucosylated residues. The fertilization envelope presented a perivitelline space and a fertilization layer, with mostly neutral glycans. The jelly layers consisted of fibers and granules, whose number and orientation differed between layers. Fibers were densely packed in J(1) and J(4) layers, whereas a looser arrangement was observed in the other layers. Jelly-layer glycans were mostly acidic and particularly abundant in the J(1) and J(4) layers. In the J(1), J(2) and J(5) layers, neutral, N-linked glycans were also observed. Mannosylated and/or glucosylated as well as galactosyl/galactosaminylated residues were more abundant in the outer layers. Many microorganisms were observed in the J(5) layer. We believe that, apart from their functions in the fertilization process, acidic and fucosylated glycans could act as a barrier against pathogen penetration.

Objective: To evaluate lymphocyte subset distribution in the secretory endometrium from infertile patients with polycystic ovary syndrome (PCOS), and the expression of the cytokines known to play a role in determining the endometrial lymphocyte pattern., Design: Experimental clinical study., Setting: Outpatient clinic in a university hospital., Patient(s): Twenty-eight patients with PCOS (PCOS group) and 6 fertile patients (control group)., Intervention(s): On days 22-26 of a spontaneous cycle, subjects underwent endometrial biopsies., Main Outcomes Measure(s): In 19 of 28 patients with PCOS and 6 controls with a late secretory endometrium, the percentage and phenotype of lymphocyte subsets were analyzed by flow cytometry. In the late secretory endometrium of 11 patients with PCOS and 3 controls, the expression of interleukins 15 and 18 and of chemokine ligand 10 was also analysed by polymerase chain reaction., Result(s): In patients with PCOS the percentage of CD56+/CD16- and of CD56bright/CD16- cells was significantly lower (median [confidence interval]: 38% [31%-52.7%] vs. 63.7% [57.7%-69%] and 17.4% [8%-41.6%] vs. 52% [43%-60%], respectively), whereas the percentage of CD3+ was significantly higher (45% [33.3%-64%] vs. 26.1% [21%-32%]) as compared with controls. Accordingly, polymerase chain reaction analysis revealed a significantly lower expression of interleukins 15 and 18 and of chemokine ligand 10 in patients with PCOS than in controls., Conclusion(s): Results demonstrated an abnormal percentage of endometrial lymphocyte subsets, associated with an impaired cytokine network in patients with PCOS. This could explain the poor reproductive potential in these patients., (Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Histochemical, lectin-histochemical, and immunohistochemical analyses were performed on parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum, to clarify the composition and distribution of oligosaccharide chains in the beta-subunit of the protonic pump H(+),K(+)-ATPase. PAS, Alcian Blue (pH 2.5) and Alcian Blue (pH 1.0) stainings detected only neutral glycoconjugates. Lectin-binding analyses included LTA, UEA-I, ConA, SBA, BSI-B4, AAA, DBA, PNA, and WGA. WGA-and PNA-bindings were also tested after beta-elimination to detect O-linked glycans. Parietal cells were negative for binding to LTA and UEA-I, and to PNA and WGA after beta-elimination, indicating the lack of (1,2) fucosylated residues and of N-linked glycans, respectively. Immunohistochemical tests with anti-alpha- and anti-beta-H(+),K(+)-ATPase were positive. Two alternative patterns of glycoconjugate distribution were found, i.e. a perinuclear and a diffuse one, indicating localization in the intracellular canaliculus and in the tubulovesicular system of the parietal cells, respectively. Both the subunits of the H(+),K(+)-ATPase and the galactosyl/galactosaminyl residues were co-distributed in both the perinuclear and the diffuse patterns, suggesting that the residues are part of the protonic pump. Glycosyl/glycosaminyl and mannosyl groups were concentrated in the tubulovesicular system, and fucosylated residues were found almost exclusively in the intracellular canaliculi; thus they are probably not included in the oligosaccharide chains of beta-H(+),K(+)-ATPase. These findings indicate that the oligosaccharide chains linked to the beta-H(+),K(+)-ATPase subunit in R. ferrumequinum have distinct features compared to the other mammals studied and confirms the taxon specificity of the chains in the proton pump.

Background: Hepatocytes are polarized epithelial cells with three morphologically and functionally distinct membrane surfaces: the sinusoidal, lateral and canalicular surface domains. These domains differ from each other in the expression of integral proteins, which concur to their polarized functions. We hypothesize that the cholestasis-induced alterations led to partial loss of hepatocyte polarity. An altered expression of membrane proteins may be indicative of functional disorders. Alkaline liver phosphatase (ALP), one of the most representative plasma membrane glycoproteins in hepatocytes, is expressed at the apical (canalicular) pole of the cell. Because the release of ALP protein in the bloodstream is significantly increased in cholestasis, the enzymatic levels of plasma ALP have major relevance in the diagnosis of cholestatic diseases. Here we assess the cholestasis-induced redistribution of membrane glycoproteins to investigate the ALP release., Materials and Methods: We performed enzymatic histochemistry, immunohistochemistry, lectin histochemistry, immunogold and lectin-and immunoblotting studies. Experimental cholestasis was induced in rats by ligation of common bile duct (BDL)., Results: The BDL led to altered membrane sialoglycoprotein targeting as well as to ultrastructural and functional disorders. Disarrangement of the microtubular system, thickening of the microfilamentous pericanalicular ectoplasm and disturbance of the vectorial trafficking of membrane glycoprotein containing vesicles were found., Conclusions: Altogether, results indicate that the cholestasis-induced partial loss of hepatocyte cell polarity leads to mistranslocation of ALP to the sinusoidal plasma membrane from where the enzyme is then massively released into the bloodstream.

A multidisciplinary study involving lectin histochemistry, IHC, immuno-lectin blotting, and immunogold was carried out to determine the distribution of sugar residues in the glycoproteins of Rana esculenta oxynticopeptic cells. We considered animals in two experimental conditions, fasting and fed. It is known that, in mammals, the tubulovesicular membranes are rich in proteins with several functions. The proton pump H(+),K(+)-ATPase, a heterodimeric complex with a catalytic alpha-subunit and a heavily glycosylated beta-subunit, responsible for acid secretion, is the most abundant. No data have been published regarding the localization and the structures of H(+),K(+)-ATPase in amphibians. In the water frog, the luminal membrane and tubulovesicular system of oxynticopeptic cells, which differ in morphology according to their functional stage, reacted with the primary gold-conjugated antibody against the H(+),K(+)-ATPase alpha-subunit. By lectin histochemistry and immunoblotting, in the oxynticopeptic cells of R. esculenta we detected the presence of N-linked glycans having fucosylated (poly)lactosamine chains, which could correspond to the oligosaccharide chains of the beta subunit. The latter are somewhat different from those described in mammals, and this is probably because of an adaptation to the different microenvironmental conditions in which the oxynticopeptic cells find themselves, in terms of their different habits and phylogeny.

The morphofunctional organization of the exocrine cells in the foregut of the red-eared slider turtle, Trachemys scripta, was investigated by histochemistry (PAS, AB pH1.0 and pH 2.5, HID-AB, Bowie), lectin-histochemistry (WGA, SBA, UEA, ConA, PNA, DBA, sialidase-SBA, sialidase-PNA, Paradoxical ConA), and immunohistochemistry (antipepsin, anti-alpha-H+,K+ ATPase) to detect regional differences and verify the existence of an oro-aboral gradient in gastric juice secretion. Observations showed that pharyngeal goblet cells have mucins with terminal residuals of GalNAc and sialic acid. In the oesophagus, sulphomucins in the goblet cells are progressively substituted by sialomucins and no glands are found. Gastric surface cells secrete mostly sialomucins with residuals of GlcNAc and GalNAc. The cardias presents glands with cells secreting mostly sialomucins, differing from the surface ones in having GalNAcalpha1,3GalNAc sequences. The fundus presents complex glands with main and lesser tubules. Cells in the main tubules secrete stable, class-III mucins with sialylated residuals of glucose and/or mannose, GalNAcalpha1, 3GalNAc, and Galbeta1,3GalNAc sequences. In the lesser tubules, the oxynticopeptic cells are found, presenting pepsinogen granules and an affinity to the anti-alpha-H+,K+ ATPase, without any oro-aboral variation. The pyloric glands have a secretion similar to that of the neck cells of the fundic glands, consisting of stable, class-III mucins mostly sialylated with a high heterogeneity of residuals such as glucose and/or mannose, fucose, GlcNAc, and GalNAc. Mucins in the foregut are probably involved in several functions such as lubrication, protection against gastric juice, osmotic regulation to increase intestinal absorption, and protection against microbial injuries.

Aim: Placental insufficiency is a pathological condition consisting of a placental functional deficit with multifactorial etiology; it can cause maternal complications such as edema, proteinuria, hypertension, etc. Our study aims to establish if placenta analysis after birth can lead to the identification of basic morphological alterations which can be easily documented and useful for the diagnosis of feto-neonatal pathologies., Methods: We examined 60 pregnant women (45 primipara, 15 multipara). They were hospitalized in the period from March 1998 to March 2004 in different pregnancy periods because of fetus growth delay. After birth, a careful examination of the placenta has been carried out soon after spontaneous birth (weight, thickness, possible morphological alterations which could be macroscopically observed) and it was followed by an anatomo-pathological examination carried out at the Anatomopathology Unit of Ospedali Riuniti in Foggia., Results: Macroscopic examination, in the group of women at the first pregnancy, showed that there were no morphological alterations in the placenta in all the cases, but the weight was normal (400- 500 g) in 8 cases and it was less than 400 g in the other 37 cases. In the group of multipara, placenta did not shown morphological alterations in all the cases, but the weight was normal in only 3 cases and it was lower in the remaining 12 cases. The placental microscopic examination pointed out: infarct focus in 34 cases (60%), 12 (35%) of which were recent and 22 (65%) were old infarct focuses; immaturity of chorionic villus in 15 (30%) of the examined placentas; increase in the cytotrophoblast mitotic index in 49 cases (90%) and placenta with normal histological appearance in 11 cases (10%)., Conclusion: Placental examination, both with macroscopic and microscopic techniques, can lead to the identification of basic morphological alterations which can be easily documented and useful for the diagnosis of feto-neonatal pathologies. A good placental functionality influences both fetal life and postnatal life. Thus, a greater attention to the placental examination in obstetric practice is suggested, especially for maternal and fetal pathologies.

Mucins in the gastrointestinal tract of Rhinolophus ferrumequinum were investigated by histochemistry and lectin histochemistry to evaluate morphofunctional variations of different regions and their possible physiological and evolutionary implications. Histochemical methods included periodic acid-Schiff (PAS), Alcian blue (AB) at pH 2.5 and 1.0 and high-iron-diamine AB pH 2.5. Binding of lectins Con A, DBA, WGA, LTA, LFA, PNA and SBA; LFA, PNA and SBA with prior sialidase treatment; and paradoxical Con A were evaluated. The oesophagus lacked glands. The stomach was divided into a short cardias, a wide fundus and a brief pylorus. The surface muciparous cells secreted sulpho- and sialomucins with N-acetylgalactosamine (GalNAc) residues, N-acetyllactosamine and (beta1,4 N-acetylglucosamine)(n) chains. Towards the pylorus, N-acetylgalactosamine residues disappeared and acidity decreased. Cardiac glands, neck cells in the fundic glands, pyloric and duodenal Brunner's glands all shared neutral, stable class-III mucins, mainly with N-acetylgalactosamine sequences. The intestine was divided into a duodenum, a jejuno-ileum and a short rectum. The goblet cells produced sulpho- and sialomucins with sialylated N-acetylgalactosamine sequences, (beta1,4 N-acetylglucosamine)(n) and N-acetyllactosamine, whose sialylation increased towards the rectum. The main features of the mucins are probably associated with the requirements of fast absorption and food passage and in protection against mechanical and pathogenic injuries.

The gastric glands of Triturus carnifex (Amphibia, Caudata) have been examined by histochemical and immunohistochemical methods with particular regard to hydrochloric acid and pepsinogen secretion. Fundic glands consist of mucous neck cells, endocrine cells and oxynticopeptic cells producing both pepsinogen and hydrochloric acid. The neck cells showed an unexpected distribution pattern which was only observed in the oral fundus, and produced neutral mucins with glycosidic residues of GalNAc and Gal beta1,3GalNAc, and in this respect they differ from the neck cells of anuran amphibians. The secretion of pepsinogen and hydrochloric acid as demonstrated by immunolabelling with anti-H,K-ATPase and with anti-pepsinogen, respectively, seems not to vary significantly along the longitudinal axis of the stomach. The mechanism of gastric acid secretion seems to be mediated by an ATPase, having similar features to the mammalian gastric H,K-ATPase, and is localised in the luminal membrane and in the subapical cytoplasm of the oxynticopeptic cells. Unusually, the same cytoplasmic areas revealed binding specificity for the winged pea lectin (WPA) from Lotus tetragonolobus, even after beta elimination, indicating the presence of fucosyl residues in N-linked oligosaccharidic chains in glycoproteins of beta-H,K-ATPase subunits.

Caveolin-1, an integral membrane protein, is the principal component of caveolae, which are specialised vesicular microdomains of the plasma membrane. Caveolae are found in most cell types, but they are most abundant in adipocytes, endothelial cells, fibroblasts, and muscle cells. Functionally, they have been implicated in endothelial transcytosis, potocytosis, and signal transduction. Recently, caveolin-1 has been found unexpectedly in the cytoplasm, mitochondria and elements of the secretory pathways of exocrine secretory cells. We have co-localised caveolin-1 and pepsinogen immunohistochemically in serous cells of oesophageal glands of the red-legged frog, Rana aurora aurora. Thus, according to its intracellular localisation pattern, caveolin-1 may be either a soluble protein, located in secretory droplets, or a protein that is inserted in caveolar membranes. Soluble caveolin-1, which is probably embedded in a lipid particle surrounded by a phospholipid shell, may be involved in intracellular and extracellular lipid transport. In the gut, caveolin-1-rich lipid particles can act as donor particles to facilitate (protein-mediated) intestinal uptake of cholesterol and phospholipids. Our findings strengthen the hypothesis that caveolin-1 has a physiological autocrine/paracrine function and demonstrate that secretion of this protein also occurs in vertebrates other than mammals, such as amphibians, which may be a useful alternative animal model to study caveolin-1.

The secretory cells of the oesophagogastric tract of the Eurasian toad, Bufo viridis, were examined using standard histochemical methods and lectin histochemistry. Two goblet cell types were found in the oesophageal epithelium, differing in their morphology and the histochemical features of the secretory granules. These contained mainly acidic glycoconjugates, both sulphated and carboxylated, and a small amount of pepsinogen. Type I goblet cells contained stable class-III mucosubstances, which were absent in Type II. No pluricellular oesophageal glands were found. The oesophagogastric junction had a superficial epithelium similar to that of the oesophageal epithelium, with alveolar pluricellular glands, secreting stable class-III mucins, and few oxynticopeptic cells. The gastric mucosa presented secretory cells both in the surface epithelium and in the gastric glands. Superficial and foveolar cells produced neutral mucins with Gal(beta)1,3GalNAc residues. Neck cells, oxynticopeptic cells and endocrine cells were found in the gastric glands. Neck cells produced stable class-III mucosubstances. A functional gradient was observed in the oxynticopeptic cells from the oral to the aboral fundus, with a decrease in pepsinogen secretion towards the aboral fundus and a possible increase in HCl secretion. In the pyloric mucosa, the oxynticopeptic cells disappeared and the glands produced only neutral mucins, without stable class-III mucosubstances.

Mucous cells from the digestive tract of the red-legged frog, Rana aurora aurora, were examined by standard histochemical methods and by lectin histochemistry. Two different goblet cell types were found in the oesophageal epithelium. Type I cells produced acidic glycoproteins with beta1,4GlcNAc oligomers, Gal beta1,3GalNAc sequences, sulphated esters on internal residues and abundant non-O-acylated terminal sialic acid bound to penultimate GalNAc. These cells also reacted with Con-A after periodate oxidation-borohydride reduction (PCS). Type II goblet cells mainly differed from type I cells in their negative reaction with PCS. Oesophageal glands consisted of mucous and serous cells. Mucous cells produced neutral stable class III mucosubstances with GalNAc, beta1,4GlcNAc and Gal beta1,3GalNAc residues. Gastric surface cells produced sulpho-sialoglycoproteins with Gal beta1,3GalNAc residues and Gal beta1,3GalNAc-sialic acid as terminal sequences. These cells did not contain stable class III mucosubstances. The mucus produced by foveolar cells was similar in composition but did not contain sulphated groups and was rich in GalNAc residues. The fundic glands consisted of mucous neck cells, endocrine cells and oxyntic cells. The neck cells produced neutral mucins containing D-mannose and/or D-glucose, beta1,4GlcNAc oligomers and Gal beta1,3GalNAc terminal dimers and were PCS-positive. Pyloric glands were of the mucus-secreting type, which produced glycoproteins with the same basic features as those produced in fundic neck cells. A single type of intestinal goblet cells produced acidic glycoproteins rich in beta1,4GlcNAc oligomers, sulphated esters on oligosaccharide chains and terminal O-acylated sialic acid bound to penultimate Gal beta1,3GalNAc. The different carbohydrate structures observed along the digestive tract of the frog may reflect specific functions of the mucus.

The results of an ultrastructural investigation of the gastric glands of the ruin lizard are reported. In this reptile the stomach can be divided into a larger fundus and a smaller pars pilorica. Fundic glands are characterized by three main kinds of cells: mucous, endocrine, and oxynticopeptic; the latter were not observed in the pyloric glands. The morphological features of the oxynticopeptic cells change from the proximal to the distal region of the fundic mucosa. In the proximal region, numerous electron-dense secretory granules, a well-developed granular endoplasmic reticulum, an evident Golgi complex, and a reduced system of smooth-surfaced vesicles and tubules in the apical cytoplasm characterize these cells. In the distal fundic region, oxynticopeptic cells possessed numerous mitochondria and a well-developed smooth-surfaced endoplasmic reticulum, but secretory granules were rare. These data suggest the existence of a gradient in the production of proteolytic enzymes, and perhaps also of hydrochloric acid, along the oral-aboral axis of the stomach. The results are discussed with regard to the evolution of the gastric glands and of the digestive mechanism in vertebrates., (Copyright 2000 Wiley-Liss, Inc.)

Mucous and oxynticopeptic cells in the gastric mucosa of the seps, Chalcides chalcides (Linnaeus, 1758) were examined by standard histochemical staining methods and by lectin histochemistry. The epithelial mucous cells lining the surface of the stomach and the mucous cells of the fundic glands elaborated mainly neutral glycoproteins with beta(1,4)GlcNAc oligomers, GalNAc glycosidic residues and Gal beta1,3GalNAc terminal sequences. The mucous cells of the fundic glands were stained specifically with the Paradoxical Con A method. The mucosecreting cells of the pyloric glands produced neutral glycoproteins, with beta(1,4)GlcNAc oligomers, GalNAc residues and Gal beta1,3GalNAc terminal sequences. Terminal L-fucose bound to the penultimate GlcNAc residues, and/or difucosylated oligosaccharides were also present. The pyloric glands did not stain with the Paradoxical Con A procedure. The morphology of the oxynticopeptic cells changes from the oral to the aboral region of the fundic mucosa. In the oral fundic tract the oxynticopeptic cells showed cytoplasm filled with zymogen granules, while in the aboral fundic region these cells contained few zymogen granules and showed cytoplasm full of empty vesicles, typical of the acid secreting cells. A secretion gradient of proteolytic enzymes and hydrochloric acid along the fundic mucosa of the seps can be hypothesised.