Morphology and taxonomic distribution of a newly discovered feature,postero-lateral glands,in pelagic nemerteans

A variety of pelagic nemerteans from our collections off California and Hawaii between 1992 and 1997 have a pair of epidermal structures, usually visible on the intact specimens, located on the ventro-lateral margins near the caudal end of the body. The only previous reports of similar structures from pelagic or any other nemerteans are for two species of the genus Plotonemertes. Histological serial sections of at least one specimen from each of about 16 morpho-species demonstrate that these are specialized glandular regions of the epidermis, which we broadly term postero-lateral glands. The objects of this study are to describe these glands at the level of light microscopy and to consider their systematic implications and possible functions. Most of the glands consist of two more or less spatially segregated types of secretory cells. One type is usually at the anterior end of the gland and resembles typical mucous goblet cells. The other type usually is the more abundant, and resembles a nemertean serous cell, with secretion that probably is relatively proteinaceous. The glands of one of the Plotonemertes specimens have two additional types of secretory cells that are relatively abundant. This study reports on postero-lateral glands from 30 specimens: three specimens of Plotonemertes in the family Protopelagonemertidae, 18 in at least three genera of the family Pelagonemertidae, six in the monotypic family Balaenanemertidae, and three of Proarmaueria in the family Armaueriidae. The glands are relatively large, with large quantities of secretory vesicles, indicating that they must be of considerable importance to the animals. However, neither structure nor location offer self-evident clues to function of these glands. We also report on different forms of regional specialization in the epidermis of Crassonemertes and Nectonemertes, both of which lack postero-lateral glands.     

Spatial distribution and cell kinetics of the glands in the human esophageal mucosa

The glands in the human esophageal mucosa have been considered rudimentary, and have been poorly studied. Only recently, their role in the defense of the esophageal mucosa in gastroesophageal reflux disease has been put in evidence. In the present study, the presence of the different esophageal gland types was observed in 82 necropsy specimens. A precise topographical study was possible in 15 specimens. Cell proliferation parameters, namely DNA synthesis and mitotic index values in the squamous epithelium and in the esophageal glands were measured in 8 patients undergoing a surgical palliative esophagectomy, after in vivo labelling with bromodeoxyuridine. Upper mucosal, lower mucosal, and submucosal glands were observed in respectively 3.7%, 87% and 99% of the 82 esophageal specimens. Our topographical analysis showed that the upper mucosal glands, lower mucosal glands, and submucosal glands are occupying respectively 0.02%, 2.61%, and 3.96% of the esophageal surface. DNA synthesis and mitotic index values in the progenitor zone of the squamous epithelium were respectively 7.91% and 0.81%, whereas the proliferative activity in the glands was extremely low. The labelling index In the excretory ducts of the glands was only 0.07%, while no labelled cells nor mitotic figures were observed in any of the glandular acini.     

The rectal glands of Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) hermaphrodites and their role in symbiont transmission

Differential interference contrast, transmission electron and epifluorescence microscopy techniques were employed to examine the ultrastructure of the rectal glands in Heterorhabditis bacteriophora hermaphrodites, with special attention to the location of Photorhabdus bacteria symbionts within these structures. Three rectal glands were clearly visualized in all examined specimens, with two glands positioned sub-ventrally and another gland located dorsally. The dorsal rectal gland in all examined specimens is larger than the subventral ones. Our observations indicate that Photorhabdus bacteria do not colonize the rectal glands of H. bacteriophora hermaphrodites, but rather are present in the most posterior-intestinal cells.     

The role of Brunner's glands in the mucosal protection of the proximal part of duodenum

In the course of a prospective study authors examined the role of the hyperplasia of Brunner's glands in the mucosal protection of proximal part of duodenum in patients with peptic ulcer, chronic pancreatitis and chronic renal insufficiency. Their method for this study was the histological examination of the endoscopic biopsy specimens. The hyperplasia of Brunner's glands occurs with significant frequency in all the three examined groups of patients, while we found it less frequently in the controls. Hyperplasia of Brunner's glands is one of the protective mechanisms of the organism, which serves the protection of the duodenal mucosa between the pyloric ring and the papilla of Vater, against the damaging effect of the hydrochloric acid.     

The coupling of RP-HPLC and ESI-MS in the study of small peptides and proteins secreted in vitro by human salivary glands that are soluble in acidic solution

The aim of this study was the development of a method based on the coupling of RP-HPLC and ESI-MS for identifying and quantifying proteins and peptides secreted by human salivary glands in vitro. Salivary gland specimens, obtained from informed patients undergoing surgical resection, were incubated in an optimized medium. Incubation media of glandular specimens, selected on the basis of cytomorphological and ultrastructural analysis, were investigated by HPLC-MS. Several salivary peptides/proteins, previously recognized in human whole saliva, were searched for along the chromatogram by the selected ion monitoring (SIM) strategy. Analysis of the incubation media of parotid glands revealed the presence of basic PRPs PC, PD, PH, IB-1, II-2, and acidic PRP-1 and PRP-3 in all of the investigated samples. Basic PRPs PB and PA, acidic PRPs, and cystatins SN and S1 were detected in all of the incubation media of submandibular glands, whereas histatin 1 was detected in only one sample. Moreover, the method allowed detection of some post-translational derivatives of known salivary proteins, as well as of several previously unidentified small peptides. The present method represents a sensitive and powerful instrument to detect peptides and proteins secreted by human salivary glands in vitro.     

The salivary glands of Aparallactinae (Golubridae) and the venom glands of Elaps (Elapidae) in relation to the taxonomic status of this genus

The venom glands of four specimens of Elaps lacteus were examined and found to be structurally similar to the glands of other Elapidae and consequently different from the variable glands of the colubrid Aparallactinae, Lycophidinae and Dispholidinae. The recently proposed removal of Elaps from the Elapidae and its inclusion in the Aparallactinae (McDowell, 1968) is discussed, and the conclusion is reached that Elaps should remain within the Elapidae.     

Taxonomic criteria in the genus Gracilaria Grev. (Rhodophyta): An experience with the western Atlantic species

Epidermal glands in Enchytraeidae are arranged in several transverse rows in each segment. These glands are more or less inconspicuous. It is possible to show up the gland cells by vital staining with Neutral Red (dilution 1:25 000 to 1:200 000 in tap- or sea-water, pH 6.0–6.8). Studies using this staining method have shown that there is a distinct pattern of epidermal glands for each species of marine Enchytraeidae investigated. The possibility of distinguishing immature specimens of different marine enchytraeid species, found in one particular locality, is demonstrated.     

Expression of epidermal growth factor in salivary adenoid cystic carcinoma

This study used an immunohistochemical technique to assess the expression of epidermal growth factor (EGF) in 40 specimens of salivary adenoid cystic carcinoma (ACC), 7 specimens of labial glands adjacent to mucocele, and 5 specimens of normal submandibular glands. In normal submandibular glands, immunohistochemically detectable EGF was demonstrated in all ductal segments, including intercalated, striated, and excretory duct cells. No EGF positive staining was found in acinar compartments. including serous and mucous acinar cells. In degenerated labial glands adjacent to mucocele, no EGF staining was detected in the remaining acinar and ductal cells. In salivary ACCs, positive EGF immunostaining was observed in one of the 5 (20%) ACCs with a solid pattern and in 13 of the 35 (37.1%) ACCs with a tubular-cribriform pattern. The overall EGF expression rate in 40 salivary ACCs was 35%. Positive EGF staining was predominantly found in tubular structures in the tubular ACCs and in duct-like structures in large cribriform patterns or in the stroma of the cribriform ACCs. There was no significant correlation between EGF expression in salivary ACCs and any of the clinicopathological parameters including patient age and sex, cancer location, TNM status, clinical stage, histologic type, perivascular or perineural invasion, focal necrosis of tumor, and cellular atypia. We conclude that the duct segments of the normal submandibular gland are the sites of EGF synthesis and secretion. In degenerated labial glands adjacent to mucocele, EGF synthesis is completely inhibited. Furthermore, EGF is mainly biosynthesized in cells forming tubular or duct-like structures in tubular or cribriform salivary ACCs, and EGF may play a biologic role, particularly as a mitogen in salivary ACC growth.     

Molecular cloning of skin peptide precursor-encoding cDNAs from tibial gland secretion of the Giant Monkey Frog, Phyllomedusa bicolor (Hylidae,Anura)

The skins of phyllomedusine frogs have long been considered as being tremendously rich sources of bioactive peptides. Previous studies of both peptides and cloning of their precursor encoding cDNAs have relied upon methanolic skin extracts or the dissected skins of recently deceased specimens and have not considered the different glands in isolation. We therefore focused our attention on the tibial gland of the Giant Monkey Frog, Phyllomedusa bicolor and constructed a cDNA library from the skin secretion that was obtained via mechanical stimulation of this macrogland. Using shotgun cloning, four precursors encoding host-defense peptides were identified: two archetypal dermaseptins, a phyllokinin and a phylloseptin that is new for this species but has been recently described from the Waxy Monkey Leaf Frog, Phyllomedusa sauvagii. Our study is the first to report defensive peptides specifically isolated from anuran tibial glands, confirming the hypothesis that these glands also contribute to chemical defense. Moreover, the discovery of novel compounds for this otherwise very well characterized species suggests that this largely neglected gland might possess a different cocktail of secretions from glands elsewhere in the same animal. We will also discuss some evolutionary implications of our findings with respect to the adaptive plasticity of secretory glands.     

Active generation glands present in neonates of some Cordylid Lizards: A case study of Cordylus macropholis (Sauria: Cordylidae)

Generation glands are holocrine epidermal glands occurring on the ventral aspect of the thigh of cordylid lizards. In most species these glands seemingly start to differentiate with the onset of sexual maturity, but macroscopic signs of generation gland activity were noted in neonates of the large-scaled girdled lizard, Cordylus macropholis. The glands of neonatal, subadult, and adult individuals were examined microscopically using standard histological techniques. The glands of the five neonatal specimens examined, including both males and females, all had the same basic structure and displayed two layers of mature glandular material. In subadult and adult specimens, the number of layers varied from seven to nine. The structure of the generation glands of C. macropholis is similar to that of the few other Cordylus species that have been described to date. They are of the protruding kind with multiple mature glandular generations. Juveniles of an additional 12 cordylid species have been examined for the presence of active generation glands. Active glands were found to be present in neonates of C. tasmani and C. tropidosternum, both of which are, like C. macropholis, terrestrial species. In C. cordylus and C. coeruleopunctatus, active generation glands are absent in neonates, but differentiate soon after birth. In other cordylid species, generation glands apparently differentiate only with the onset of sexual maturity. J. Morphol. 235:177–182, 1998. © 1998 Wiley-Liss, Inc.     

The tongue morphology and lingual gland histochemistry of Ligurian Sea odontocetes

The morphology and histomorphology of the tongue and the histochemistry of the lingual glands of eight specimens from four species of Ligurian Sea odontocetes (Stenella coeruleoalba, Tursiops truncatus, Grampus griseus, and Ziphius cavirostris) were studied. The shape of tongues and the appearance of their dorsal surfaces differed between species. The lingual glands differed in size, distribution, and histochemistry by species. In S. coeruleoalba and G. griseus, a strong alcianophilic mucous material was detected in the lingual glands, while neutral and acidic mucous substances were observed in the most proximal secretory acini. In G. griseus, small simple alveolar apocrine glands were also found, and the duct of the serous lingual glands in Z. cavirostris is of apocrine type. Numerous mechanoreceptors were observed. Only the tongue of the young specimens showed marginal papillae: their histomorphological composition is consistent with the hypothesis that they create a tight seal between the tongue and the roof of the cavity in order to create suction. This comparative study suggests that differences in tongue morphology and in the morphology and histochemistry of lingual glands might be related to feeding habits.     

The Esophageal Glands of Pratylenchus Filipjev and Apratylenchoides belli n. gen. n. sp. (Nematoda: Tylenchoidea)

The esophageal glands in the genus Pratylenchus occur in a large, single ventral lobe except for four populations in which a few specimens had the glands located dorsally. Apratylenchoides belli n. gen. n. sp. in the subfamily Radopholinae is proposed for a species having two esophageal glands in a large dorsal lobe and one gland in a smaller, shorter ventral lobe.     

Expanding the ‘enemy-free space’ for oribatid mites: evidence for chemical defense of juvenile Archegozetes longisetosus against the rove beetle Stenus juno

Adult oribatid mites are thought to live functionally in ‘enemy-free space’ due to numerous morphological and chemical defensive strategies. Most juvenile oribatid mites, however, lack hardened cuticles and are thus thought to be under stronger predation pressure. On the other hand, the majority of oribatids have exocrine oil glands in all developmental stages, possibly rendering chemical defense the crucial survival strategy in juvenile Oribatida. We manipulated tritonymphs of the model oribatid mite Archegozetes longisetosus to completely discharge their oil glands and offered these chemically disarmed specimens to the polyphagous rove beetle Stenus juno. Disarmed specimens were easily consumed. By contrast, specimens with filled oil glands were significantly protected, being rejected by the beetles. This is the first direct evidence that oil gland secretions provide soft-bodied juvenile oribatids with chemical protection against large arthropod predators.     

Quantitative low-resolution analysis of colon mucosa

A general concept is presented for the analysis of histopathologically adenomatous structures at low levels of magnification. The algorithm is based upon structures of glands, not upon structures of single cells. Low microscopic magnification was used to assess the following parameters in colon mucosa: minimum diameter of glands, minimum distance to neighboring glands, number of neighbors, area of glands and circumference of glands. Twenty different specimens were analyzed for each of the following diagnostic groups: healthy tissue, tubulovillous adenoma and moderately to highly differentiated adenocarcinoma of the colon. Statistically significant differences (p less than or equal to 0.01) were obtained for each measured parameter for each group. The data indicate that low-resolution morphometry can be used successfully for the automatic separation of healthy, benign and malignant growths in adenomatous tissue.     

The distribution of sympathetic adrenergic,tyrosine hydroxylase- and neuropeptide Y-immunoreactive nerves in human axillary sweat glands

Summary The innervation of human axillary sweat glands was studied by using the specific SPG (sucrose-potassium phosphate-glyoxylic acid) catecholamine histofluorescence method and the peroxidase-antiperoxidase (PAP) immunocytochemical method. The present results demonstrated that human sweat glands are surrounded by nerves containing a weak tyrosine hydroxylase activity. Nerves showing catecholamine histofluorescence could be visualized around the sweat glands only in the presence of exogenous catecholamine (adrenaline in the local anestheticum). In all tissue specimens studied fluorescent adrenergic nerves could be seen around arteries and arterioles corresponding to the distribution of neuropeptide Y-like immunoreactive nerves.     

The distribution of sympathetic adrenergic, tyrosine hydroxylase- and neuropeptide Y-immunoreactive nerves in human axillary sweat glands

The innervation of human axillary sweat glands was studied by using the specific SPG (sucrose-potassium phosphate-glyoxylic acid) catecholamine histofluorescence method and the peroxidase-antiperoxidase (PAP) immunocytochemical method. The present results demonstrated that human sweat glands are surrounded by nerves containing a weak tyrosine hydroxylase activity. Nerves showing catecholamine histofluorescence could be visualized around the sweat glands only in the presence of exogenous catecholamine (adrenaline in the local anestheticum). In all tissue specimens studied fluorescent adrenergic nerves could be seen around arteries and arterioles corresponding to the distribution of neuropeptide Y-like immunoreactive nerves.     

Carbohydrate histochemistry of human Brunner's glands

Summary Brunner's glands are known to produce neutral mucins. In order to achieve a better knowledge of their carbohydrate profile, we used five peroxidase-labeled lectins on surgical specimens of human duodenum. This method allowed us to identify at least two different types of neutral mucins in Brunner's glands secretion, thus demonstrating a heterogeneous mucin production. The structure of terminal oligosaccharidic chains in these glycoproteins has also been hypothesized.     

The thyroid and parathyroid glands in the Giant panda, Ailuropoda melanoleuca

Observations are submitted upon the anatomy of the thyroid and parathyroid glands of Ailuropoda melanoleuca following gland investigation in three specimens. Variations of thyroid configuration and of parathyroid topography are noted, the thyroid vasculature is described in detail and an initial contribution is made to thyroid and parathyroid histology in this genus.     

Carbohydrate histochemistry of human Brunner's glands

Brunner's glands are known to produce neutral mucins. In order to achieve a better knowledge of their carbohydrate profile, we used five peroxidase-labeled lectins on surgical specimens of human duodenum. This method allowed us to identify at least two different types of neutral mucins in Brunner's glands secretion, thus demonstrating a heterogeneous mucin production. The structure of terminal oligosaccharidic chains in these glycoproteins has also been hypothesized.