Tubular Glands Research Articles

Anatomical and histological adaptations of digestive tract in relation to food and feeding habits of lizardfish, Synodus variegatus (Lacepède, 1803)

The adaptations in anatomical and histological structures of the digestive tract of fish are correlated with their food and feeding habits. An understanding of these habits is essential to emphasize the related functional mechanisms of fish digestive physiology. Little is known about the adaptations of the alimentary tract of coral reef fish to food and feeding strategies in the Egyptian Red Sea. The present study investigated the anatomical and histological structure of the digestive tract of the lizardfish, Synodus variegatus. The results indicated that the oesophagus in S. variegatus is a short, narrow and distensible muscular tube, that is adapted to conduction of food. The mucosa is composed of a thin stratum of simple columnar epithelium opens to the lumen and a thick layer of mucous tubular glands located at the base in both the anterior and posterior oesophagus. The muscular layer is formed of one circular layer. The stomach has a great distensibility with a bag-like shape to enable the fish to swallow relatively huge preys. Further, it has numerous gastric glands in the cardiac portion for food digestion. As for the pyloric portion, it is a very dense layer of muscularis, which contributes in regulating the passage of digested food to the intestine. The relative length of gut ranges from 0.67 to 0.73 cm with an average of 0.7 ± 0.02 cm. The intestine is a short uncomplicated tube. The mucosal folds in the anterior intestine are very long, numerous and with round tips. Such structures are shorter and fewer in number towards the mid intestine, and much thicker and blunt in the posterior intestine. The epithelial lining of the intestine consists of columnar cells for absorption, and numerous large goblet cells for the lubrication of feces. Finally, based on the findings of the anatomical and histological investigations, it may be concluded that there is a correlation between the adaptations in the digestive tract structure of the lizardfish, S. variegatus, and their feeding habits.

Structural adequacy of the digestive tract supports dual feeding habit in catfish Pachypterus khavalchor (Siluriformes: Horabagridae)

Lepidophagy is comparatively rare amongst teleost fishes, yet our understanding of this specialization is lacking. Therefore we examined the digestive tract features of Pachypterus khavalchor using morphological, osteological, histological and histochemical techniques to comprehend and relate structural organization of digestive tract with scale eating habit. Morphologically, the alimentary canal is defined by a short and muscular esophagus, well-developed stomach and comparatively short intestine. Gut content analysis and intestinal coefficient value (0.53 ± 0.01) revealed that P. khavalchor exhibit both carnivory and lepidophagy. However, P. khavalchor primarily feeds on the scales (67.47%) and other chitin-rich material like aquatic insects (17.62%), aquatic larvae (8.66%) which affirms its solid association with chitinase producing endosymbionts in the gut. Lepidophagy is further supported by the osteological observations. The perfect segregation of the functions such as food capture, ingestion and processing amongst the different types of teeth located in the oral cavity and pharyngeal region thus could be taken as evolutionary adaptations in scale eaters to support lepidophagy. Specialized arrangement of the esophageal and stomach epithelial folds could be altogether taken as an adaptation with the end goal to frame the scale stacks and accordingly facilitate the handling and processing of chitin-rich bolus. The esophageal mucosa is simple squamous epithelium instead of stratified epithelium with numerous goblet cells to withstand the mechanical harm by hard-food stuff like scales. The cardiac and fundic regions exhibited large number tubular gastric glands with simple columnar epithelium. Surface cells of all three stomach regions stained positive for PAS staining. The intestine is without pyloric caeca and is divided into anterior and posterior region. Histologically it is characterized by simple columnar epithelium with brush border and numerous goblet cells throughout its length. Presence of large number microvilli on anterior and posterior intestine was noticeable. Intestinal goblet cells reacted positively to PAS, AB (pH 1) and AB (pH 2.5). Secretions of goblet cells are important for lubricating and protecting the epithelium. The results of present investigation improve the understanding of the digestive physiology of scale eaters in general and P. khavalchor in particular. Overall, our data indicates that though P. khavalchor predominantly feeds on scale, the digestive physiology is adapted to support dual feeding habit (lepidophagy and carnivory).

HISTOCHEMICAL ANALYSIS OF STOMACH OF GRASSCUTTER (Thryonomys swinderianus)

The Grasscutter (Thryonomys swinderianus), is a wild herbivorous rodent peculiar to Africa. It is widely eaten in Nigerian rural communities as a protein source hence its domestication as microlivestock. There is paucity of data on the histochemical studies. This study was aimed at histochemically analyzing the stomach in order to determine if it exhibits regional differences in its qualitative expression of acid, neutral and carboxylated mucin. Seven animals obtained from the wild and domesticated in the animal house of the Department of Human Anatomy, Ahmadu Bello University, Zaria were used. Histologically, stomach of the Grasscutter was simple, glandular and composed of three regions: cardia, fundic‐body and pyloric. Cardia region showed enlongated tubular glands, coiled at the lower end with an opening continuous with the long conspicuous gastric pits. Fundic‐body region showed numerous gastric glands which open into fewer shorter gastric pits while the pyloric region showed simple tubular glands which are highly branched as such obscures the depth of the gastric pits. Histochemically, stomach of the Grasscutter exhibits regional polymorphism in the mucin content with the glands showing weak alcianophilic reactions. Cardia and pyloric regions demonstrated neutral periodic acid Schiff (PAS) reaction characterized by purple coloration thus indicating the presence of neutral mucins. Fundic‐body region exhibited strong PAS positive reaction particularly at the apical cytoplasm of the oxynticopeptic cells indicating the presence of carboxylated mucins. Results demonstrate that regional differences in the expression of mucins occur in the stomach of African Grasscutters, thus this may provide basic information for further nutritional and conservative studies.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Vector Competence of Thrips Species to Transmit Soybean Vein Necrosis Virus.

Soybean vein necrosis virus (SVNV) is a newly discovered species of tospovirus infecting soybean plants that is transmitted by the primary vector, soybean thrips (Neohydatothrips variabilis), and two additional secondary vectors, tobacco thrips (Frankliniella fusca) and eastern flower thrips (F. tritici). This study was undertaken to elucidate the association between virus acquisition [6, 12, 24, and 48 h acquisition access period (AAP)] and transmission efficiency [12, 24, and 48 h inoculation access period (IAP)] in the primary vector, N. variabilis, and to examine the mechanisms of vector competence by analyzing the effect of AAP (6, 12, and 24 h) on virus infection in various tissues. In addition, we examined virus infection in tissues of the two secondary vectors. We found a significant effect of virus acquisition on transmission efficiency, transmission rate post 6 and 48 h AAP was significantly lower than 12 and 24 h AAP. Our analysis did not reveal a correlation between virus transmission rate and virus RNA in corresponding N. variabilis adults. On the contrary, N. variabilis adults harboring higher accumulation of the virus (>104) resulted in lower transmission rates. Analysis of SVNV infection in the tissues revealed the presence of the virus in the foregut, midgut (region 1, 2, and 3), tubular salivary glands and principal salivary glands (PSG) of adults of all three vector species, however, the frequency of infected tissues was highest in N. variabilis followed by F. fusca and F. tritici. The frequency of SVNV infection in individual tissues specifically the salivary glands was lowest after 6 h AAP compared to 12 and 24 h AAP. This finding is in agreement with the transmission assays, where significantly lower virus transmission rate was observed post 6 h AAP. In addition, N. variabilis adults with high PSG infection (12 and 24 h AAP) were likely to have high percentage of foregut and midgut region 2 infection. Overall, results from the transmission assays and immunolabeling experiments suggest that shorter AAP results in reduced virus infection in the various tissues especially PSG, which are important determinants of vector competence in SVNV-thrips interaction.

Oviduct, Egg, and Egg Sac Structures in the Siberian Salamander, <i>Salamandrella keyserlingii</i> (Caudata, Hynobiidae): a Histological and Histochemical Study

Unraveling morphological and chemical features of the eggs’ jelly layers and other clutch elements, formed by the oviduct of a female, is necessary for the understanding of reproductive adaptation in amphibians. Our study is the first microstructural and histochemical descriptions about the complexity of oviduct, ovisac, jelly layer of the ovum, and egg sac in hynobiid salamanders. We examined female Salamandrella keyserlingii in preovulatory (gravid) and ovulatory (spent) conditions using anatomical, histological, and histochemical methods. Each ovum was covered with two jelly layers. All ova from one oviduct fell into one egg sac. Inner space of the oviduct, in which ova were passed through, was filled with jelly-like substances designated as «intermediate fluids». We named the membrane-like outer layer of the egg sac as «theca». Jelly layers surrounding the ovum were formed by the oviducal tubular glands of the pars recta and pars convoluta of the oviduct, consisting of acidic and neutral glycoproteins. In the ovisac (i.e., homologous uterus), there were three glandular regions and one aglandular dilatable ovisac. Of the ovisac, glands A, B, and C secreted acidic and neutral glycoproteins for the intermediate fluids, neutral glycoproteins for the theca, and mucus-like materials with a neutral glycoprotein nature, respectively. We suggest that these mucus-like materials are essential to attaching the adhesive tips of the egg sacs to some substrates during oviposition.

HISTOLOGICAL STRUCTURE OF THE KINTAMANI DOG ON THE SEXUAL MATURITY PERIOD

The objective of this study was to determine the histological structure of uterus of the kintamani dogs on the sexual maturity period. In this study using five samples of uterine organs of the kintamani dog. The tissue were taken from corpus of the uterine. The histological structure was observed using hematoxylin-eosin (HE). Identification of the histological structure of uterus observed with a microscope at 100x and 400x magnification. The results showed the endometrial lining consisted a single layer of the columnar epithelium and lamina propria with tubular glands, myometrium consisted of smooth muscle and perimetrium with connective tissue, nerves and blood vessels

The Histological Study of Proventriculus Stomach in Iraqi Black Francolin (Francolinus francolinus) and Common Teel (Anas Crecca)

Six adult of black Francolin and six of adult of common Teel were prepared for the histological study of true stomach. The samples from proventriculus of two birds which stained with routine staining by hematoxylin and eosin. The wall of proventriculus in two types of birds consists of four layers or tunics: the first was tunica mucosa had longitudinal folds and lined by simple columnar epithelium. The lamina propria contained simple tubular gland, the super facial gland in Common Teel was longer than in the black Francolin. The tunica sub mucosa contained compound tubular gland, the tunica muscularis in the in both species was consist of two type of smooth muscles inner, circular and outer longitudinal the tunica musculris in black Francolin were thicker than in the Common Teel the tunica serosa in the both species about loss connective tissue contained blood and lymph vessels.

Гістоструктурні показники перешийку яйцепроводу гусок у продуктивному періоді першого циклу яйцекладки

The oviducts of the geese of large grey breed of 8 - 13 months of age were investigated. The macroscopic parameters of the organ were determined in each group. For histological studies, the samples of oviduct isthmus were fixed in a 10% aqueous formalin solution. The histological slides were staining by the following methods: hematoxylin and eosin, tricolor method (by Mallory), methyl green-pyronin (by Brashe), PAS-reaction and alcian blue. It was established that the period of egg-laying in the goose of a large grey breed began at the age of 10 months with the peak of egg-laying at the 11th - 12th months of age. Oviducts of geese of the 8th and 9th month of age are not macroscopically differentiated into divisions. Structural features of the wall of the oyiduct isthmus were determined at the microscopic level. The thickening of the isthmus wall occurred proportionately to the mucous membrane and muscle membranes. The beginning of the formation of the secretory apparatus of the isthmus came from the age of 8 to 9 months of the geese. Since the age of 10 months, the parameters of the thickness of the mucous membrane and the height of folds have not veraciously changed. It is a feature of the completion of the relief formation of mucous membrane and the secretory apparatus. There was a maximum increasing of the diameter of the glands of the mucous membrane for geese of this age group. It is an indicator of the completion of the differentiation of the glandular apparatus of the isthmus at the time of the start of the egg-laying. The morphometric indices of lumen epithelium and glands decreased by almost 1.4 times when egg, surrounded by membranes, is presented in the isthmus. It is caused by the extrusion of the secret and the formation of the material of the subshell membranes. The height of the folds of the mucous membrane and the diameter of the tubular glands in the geese of 13 months of age did not veraciously change, with a decreasing of egg productivity on 35%. Wherein, the thickness of the mucous membrane even increased. Such dynamics of morphometric indices is the result of accumulation and stagnation of the secret in the cytoplasm of glandular cells.

Developmental Studies of the Gastric Junctions of the Post-hatching Muscovy Duck (Cairina moschata)

The current study was carried out on 24 apparently healthy post-hatching Muscovy ducks of both sexes ranging from 1-60 days old. They were divided into 5 age groups to investigate the development of the junctions of the stomach; esophago-proventricular junction, proventriculo-gizzard junction (Isthmus gastris) and ventriculo-duodenal junction by using light and scanning electron microscopy. The longitudinal folds of the esophago-proventricular junction were separated by longitudinal grooves and they were crossed by thin transverse ridges; some of the longitudinal folds were branched toward the proventriculus at 60 days old. At one day old, the lymphoid infiltrations were observed in the lamina propria at the esophago-proventricular junction. With the advancement of the age, abundant diffused lymphoid infiltrations and esophageal tonsil were observed. In all age groups, the cuticle covering of the mucosa at proventriculus-gizzard junction increased in thickness toward the gizzard. Moreover, in one day old duckling, the proventricular glands were observed underneath the gizzard tubular glands, these glands were become well developed at 60 days old. The lamina propria of the gizzard-duodenal junction showed slight lymphatic infiltrations at one day old age. Lymphatic infiltrations and more lymphatic aggregations were abundant at 7-15 days. While between 30-60 days age, lymph nodules were distinct. Numerous endocrine cells were also observed in mucosa of the gizzard-duodenal junction.

Respiratory Epithelial Adenomatoid Hamartoma


 A 65-year-old man consulted with a history of chronic snorting with a sensation of obstruction in the left side of the nasopharynx particularly when in supine position. A few days prior to consult, the patient had blood-tinged nasal discharge, thus this admission. No other symptoms were reported.
 
 Nasal endoscopy showed a sessile exophytic lesion with a vaguely nodular surface, seen as a polypoid nasopharyngeal mass on Computed Tomography scan. (Figure 1)
 
 Excision of the mass was performed. Received in the surgical pathology laboratory was a 1.8 x 1.5 x 0.6 cm red to brown, rubbery to firm, vaguely ovoid mass with a nodular external surface. Cut section showed a light gray solid surface. 
 
 Microscopic examination shows a broad-based exophytic mass with invaginations of the surface epithelium and proliferated glands within the stroma. (Figure 2) The glands are tubular or variably dilated - many are lined by a respiratory-type epithelium with goblet cells and a thickened basement membrane, while the tubular glands are lined by a monolayered cuboidal epithelium. (Figure 3) Based on these features, we signed the case out as a respiratory epithelial adenomatoid hamartoma (REAH).
 
 REAH is a benign proliferation of sinonasal tract glands derived from the surface epithelium.1 It occurs primarily in male adults, with a median age in the sixth decade of life. Most cases arise in the posterior nasal septum, while less common sites of involvement include other parts of the nasal cavity, the nasopharynx, and paranasal sinuses.2 Common symptoms include nasal obstruction, stuffiness, and epistaxis.1,3,4
 
 REAH presents as a polypoid lesion and may measure up to 6 cm in widest diameter.1 Microscopically, there is a proliferation of small to medium-sized glands dispersed in abundant stroma. Invagination of the glands from the surface epithelium may be seen.3 The glands are round to oval, lined by respiratory-type epithelium with admixed goblet cells. Thickened basement membranes surround some of the glands, and smaller seromucinous glands lined by cuboidal epithelium may also be admixed among the latter. Other alterations may include squamous, chondroid, and osseous metaplasia.1,4
 
 Rarely, REAH may occur synchronously with inverting sinonasal papillomas or inflammatory polyps.1 It may be mistaken for these two entities along with sinonasal low-grade adenocarcinomas. Careful attention to the typical morphology including absence of an infiltrative growth pattern and atypia allow distinction from these entities particularly the malignant mimics.3 A related entity is a seromucinous hamartoma with which REAH is believed to form a morphological spectrum.1
 
 REAH is benign and complete excision confers cure.1 Malignant transformation has not been reported.1,3,4

Enteroendocrine profile of α-transducin and α-gustducin immunoreactive cells in the chicken (Gallus domesticus) gastrointestinal tract.

The enteroendocrine profile and distribution patterns of the taste signaling molecules, α-gustducin (Gαgust) and α-transducin (Gαtran) protein subunits, were studied in the gastrointestinal (GI) tract of the chicken (Gallus domesticus) using double labeling immunohistochemistry. Gαtran or Gαgust immunoreactivity was observed in enteroendocrine cells (EEC) expressing different peptides throughout the entire GI tract with different density. In the proventriculus tubular gland, Gαtran or Gαgust/gastrin (GAS) immunoreactive (-IR) cells were more abundant than Gαtran/or Gαgust containing glucagon-like peptide-1 (GLP-1) or peptide YY (PYY), whereas only few Gαtran or Gαgust cells co-stored ghrelin (GHR) or 5-hydroxytryptamine (5-HT). In the pyloric mucosa, many Gαtran or Gαgust-IR cells co-expressed GAS or GHR, with less Gαtran or Gαgust cells containing GLP-1, PYY, or 5-HT. In the small intestine, a considerable subset of Gαtran or Gαgust-IR cells co-expressed 5-HT in the villi of the duodenum and ileum, PYY in the villi of the jejunum, CCK or GLP-1 in the villi of the ileum, and GHR in the duodenum crypts. In the large intestine, many Gαtran or Gαgust-IR cells contained 5-HT or GLP-1 in the villi of the rectum, whereas some Gαtran/Gαgust-IR cells co-expressed PYY- or CCK-, and few Gαtran/Gαgust-IR cells were positive for GHR-IR. In the cecum, several Gαtran or Gαgust-IR cells were IR for 5-HT. Finally, many Gαtran/Gαgust cells containing 5-HT were observed in the villi and crypts of the cloaca, whereas there were few Gαtran or Gαgust/CCK-IR cells. The demonstration that Gα-subunits are expressed in the chicken GI enteroendocrine system supports the involvement of taste signaling machinery in the chicken chemosensing processes.

Comparative anatomical studies on the glandular stomach of the rock pigeon (Columba livia targia) and the Egyptian laughing dove (Streptopelia senegalensis aegyptiaca).

The rock pigeon (RP) and the laughing dove (LD) are common and widely distributed species in African countries, including Egypt. The present work was carried out to characterize the comparative features of the glandular stomach (proventriculus) in these two birds, which share diets and habitats. In both species, the proventriculus is an elongated spindle obliquely situated in the cranial two-thirds of the body cavity. The length and weight of the proventriculus in the RP were about one and half times greater than that of the LD. Histologically, the proventricular wall generally consisted of the mucosa (thickest), submucosa, muscular and serosa layers. The proventricular glands occupied most of the wall of the proventriculus within the lamina propria of the mucosa. The glands are tubuloalveolar in type, consist of variable shaped lobules and are more condensed in LD than in RP. At the proventricular-gizzard junction (PGJ), the proventricular glands were observed external to the tubular glands of the gizzard in the RP, whereas in LD, these glands end abruptly and are separated from the tubular glands of the gizzard by a short distance. A scanning electron microscopy (SEM) of the proventricular lumen in RP revealed that the openings of the proventricular glands have an irregular outline surrounded by concentrically arranged mucosal folds that resemble a rosette shape. In the LD, these openings have a regular outline surrounded by thinner, widely spaced mucosal folds. To our knowledge, these results identified the structure of the proventriculus in RP and LD for the first time.

Comparative morphology of the internal female genitalia in two species of Mantophasmatodea

The female internal reproductive anatomy of two mantophasmatodean species, Karoophasma biedouwense and Viridiphasma clanwilliamense, is described in detail using X-ray micro-computed tomography, light microscopy, and scanning electron microscopy. We identified paired ovaries containing panoistic ovarioles, a spermatheca surrounded by an epithelium of glandular structure, together with a spermathecal duct surrounded by muscle cells. Tubular accessory glands, which are present in many insects, are missing throughout the female genital tract of heelwalkers. Therefore, we suggest that the gland cells included in the epithelium of the ventral genital chamber of heelwalkers produce the secretions used for building egg pods in which eggs and sand are glued together. The two species investigated differ in the number of ovarioles per ovary and in the shape of their spermatheca. This investigation adds to the scarce information on mantophasmatodean internal genitalia and provides a basis for further research on reproductive behavior in heelwalkers.

Histomorphometrical changes of oviduct during the long-term exposure of breeder hens to extra thyroxine.

In this research a 100 day long treatment period was considered to unmask the probable adverse effects of long-term induced hyperthyroidism on histomorphometrical attributes of the oviduct in broiler breeder hens. A total of seventy 47-week-old Cobb 500 breeder hens were randomly allotted to two treatment groups (5 replicates of 7 hens each). Thyroxine (T4) was orally administered to the hyperthyroid group (0.3 mg/bird/d) for 100 consecutive days; whereas the control group received drinking water only throughout the trial. At 64 weeks of age, 2 birds per replicate were killed by cervical dislocation and their oviducts were removed. For histomorphometrical observations, segments were taken from five different regions. After tissue preparation and staining with haematoxylin and eosin, histological layers were evaluated using light microscopy. The assessment of histomorphometrical characteristics of oviduct showed the height of mucosal folds in the magnum, thickness of mucosal folds of the magnum and uterus, thickness of tunica muscularis in the magnum and vagina, epithelial thickness of the isthmus and vagina, and uterine tubular glands percentage were decreased in the hyperthyroid birds compared with the control counterparts. The results showed long-term induced hyperthyroidism was associated with a decrease in a number of histomorphometrical traits in different regions of the oviduct. Some studies should be done to clarify to what extent the long-term maternal hyperthyroidism might affect the egg production, fertility rate, duration of fertility, and sperm penetration rate to make a final decision on exploitation of this preventative treatment to diminish the ascites incidence in progeny chicks.

Ultrastructure of the tubular glands in the isthmus region of the oviduct in laying and natural moulting commercial egg-type chickens.

The study investigated the ultrastructural characteristics of tubular gland and duct cells, as well as luminal gland cells in the isthmus region of the oviduct of laying and natural moulting hens. Tubular glands in laying birds were composed of type 1 and 2 cells. Based on the preponderance of each cell type, in relation to the location of a developing egg in the oviduct of the domestic fowl, these gland cells may represent different functional states of the same cell. The findings of the study on natural moulting birds suggest that autophagy is a process confined to the early stages of degeneration, while necrosis occurs in the terminal stages.

VEGFA and VEGFR2 RNAscope determination in gastric cancer.

Gastric cancer is the fifth most common cancer and third leading cause of cancer-related death worldwide. Several studies on angiogenic blocking agents in gastric cancer revealing promising results by the use of monoclonal antibodies against VEGFA or its receptor VEGFR2 or against VEGFA activating pathway. The validation of biomarkers useful to better organize the clinical trials involving anti-angiogenic therapies is crucial. Molecular markers such as RNA are increasingly used for cancer diagnosis, prognosis, and therapy guidance as in the case of the targeted therapies concerning the inhibition of angiogenesis. The aim of this study is to set the conditions for evaluating the expression of VEGFA and VEGFR2 in gastric cancer specimens and in healthy gastric mucosa by the use of RNAscope, a novel RNA in situ hybridization (ISH) method that allows the visualization of a specific gene expression in individual cells. We found the increased expression of VEGFA in the tubular glands and VEGFR2 in the endothelium of gastric cancer samples mainly in the T2, T3 and T4 stages of tumor progression as compared to the healthy controls. These resultsobtained by the application of this highly sensitive method for oligonucleotide detection the role of angiogenesis in gastric cancer progression already highlighted by conventional immunohistochemical methods, and offer significant promise as a new platform for developing and implementing RNA-based molecular diagnostics also in the conditions in which immunohistochemistry is not applicable.

Clinicopathological Characteristics and KRAS Mutation Status of Endometrial Mucinous Metaplasia and Carcinoma.

Mucinous metaplasia of the endometrium occurs as a spectrum of epithelial alterations ranging from the formation of simple, tubular glands to architecturally complex glandular proliferation with intraglandular papillary projection and cellular tufts. Endometrial mucinous metaplasia often presents a diagnostic challenge in endometrial curettage. We analyzed the clinicopathological characteristics and the mutation status for V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) of 11 cases of endometrial mucinous metaplasia. Electronic medical record review and histopathological examination were performed. KRAS mutation status was analyzed using a pyrosequencing technique. Cases were classified histopathologically into simple (5/11) or papillary (6/11) mucinous metaplasias. All (6/6) papillary mucinous metaplasias were associated with atypical hyperplasia/endometrioid intraepithelial neoplasia (AH/EIN; 1/6) or carcinoma (5/6), whereas in a single patient with simple mucinous metaplasia, grade 1 endometrioid carcinoma was incidentally detected. The difference in frequency of association of the metaplasia with AH/EIN or carcinoma was significant (p=0.015). KRAS mutations were identified in five out of six cases of papillary mucinous metaplasias, comprising three cases with G12D and two with G12V mutations; the frequency of KRAS mutation was significantly higher (p=0.015) than in cases of simple mucinous metaplasia (0/5). Papillary mucinous metaplasia is frequently associated with endometrial neoplastic lesions. The high incidence of KRAS mutations in papillary mucinous metaplasia suggests that papillary mucinous metaplasia may be a precancerous lesion of a certain subset of mucinous carcinomas of the endometrium.

Structure of the alimentary tract in the Atlantic mudskipper Periophthalmus barbarus (Gobiidae: Oxudercinae): anatomical, histological and ultrastructural studies

The alimentary tract of oxudercine gobies is characterized by a lack of an anatomically distinct stomach, owing to which they are classified as stomachless. Since the environment, food requirements, and feeding habits have a significant impact on the anatomy of the alimentary tract of fish, it was assumed that predominantly carnivorous, semi-terrestrial mudskippers would have a stomach. In order to verify this hypothesis, anatomical, histological, histochemical and ultrastructural analysis of the alimentary tract of the Atlantic mudskipper Periophthalmus barbarus was performed. The results revealed that despite a lack of clear anatomical distinction within the alimentary tract, there were four well-distinguished sections visible at the histological level: oesophagus, stomach, intestine, and rectum. The division was enhanced by the presence of a pyloric sphincter and an ileorectal valve. The stomach contained tubular glands composed of oxynticopeptic cells. Gland cells had pepsinogen granules and a well-developed tubulovesicular network of smooth membranes, which indicates the secretion of gastric juice. The presence of neutral mucus in the apical region of surface epithelial cells as protection against hydrochloric acid as well as the presence of active pepsin also confirm gastric function. However, low pepsin activity seems to implies low protein digestion. The results of this study indicate that the Atlantic mudskipper P. barbarus has a functional stomach.

A morphological description of Onchidium reevesii (Gastropoda: Eupulmonata: Systellommatophora)

ABSTRACTThis morphological description of Onchidium reevesii (J.E. Gray, 1850), a common species on the coast of China, previously called Onchidium struma (Qiu, 1991), includes the external features and the digestive, nervous and reproductive systems. The radula and the penis are illustrated using electron microscopy. The surface of the notum is granular and hundreds of dorsal papillae are present, each with an eye. The position of the pneumostome is mid posterior on the hyponotum. The radular formula varies from 62:1:62 to 110:1:110. A convolute tubular rectal gland is present. Unusual features of the reproductive system include the penis having a proximal long, spiral stalk followed by a distal region covered with hooks, and the flagellum of the penial gland being long and heavily coiled.

Long-term effects of thyroxine-induced hyperthyroidism on the histological attributes of the oviduct in broiler breeder hens

A 4-week-long administration of extra thyroxine (T4) in broiler breeder hens was recommended to lower the cold-induced ascites incidence in the progeny chicks. A hypothesis was tested that the long-term-induced hyperthyroidism might influence the histological traits of oviducts in the exposed hens. A total of 70 47-week-old Cobb 500 breeder hens were randomly allotted to two treatment groups (5 replicates of 7 hens each), including the control (CON) and hyperthyroid (HYPER). Thyroxine (T4) was orally administered to the HYPER group (0.3 mg/bird day−1) for 100 successive days; whereas the CON group received the drinking water only throughout the trial. At 64 weeks of age, two birds per replicate were cervically dislocated and their oviducts were removed for histological sectioning and staining. Results showed that secretory cells were detected in the anterior infundibulum and the number of secretory cells in the hyperthyroid hens was smaller than that of the control group. Thyroxine-treated hens recorded a decreased number of tubular glands in the magnum as compared to that of the control hens. The circular muscle layer of isthmus showed a more regular arrangement in the control in comparison with the T4-treated hens. Additionally, the number of uterine tubular glands in the hyperthyroid group was lower than that of the counterparts. A decline in the vaginal epithelial thickness in the hyperthyroid hens was also recorded as compared to the control birds. Overall, the long-term administration of thyroxine was associated with considerable impacts on different parts of the oviduct. The question as to what extent the long-term maternal hyperthyroidism might affect the basal metabolic rate, egg production, fertility rate, duration of fertility, hatchability, and the chick quality remains open to make a final decision on exploitation of this preventative treatment to diminish the ascites incidence in progeny chicks.