Histological structure of the digestive tract and digestive enzymatic activity of juvenile Pacific seahorse (Hippocampus ingens)

The histological structure, histochemical features, and enzymatic activity of the digestive tract of juvenile Pacific seahorse (Hippocampus ingens) are described to provide information during the cultivation of this species. Serial histological sections were stained with either hematoxylin-eosin, alcian blue-PAS, toluidine blue, Sudan black, Masson's trichome, and ninhydrin-Schiff to describe the general features and the presence of glycogen, mucopolysaccharides, lipids, muscle layers, and proteins, respectively. The enterocytes height and the mucosal villi height in the esophagus and intestines were measured. Additionally, the digestive enzymes trypsin, chymotrypsin, lipase, amylase, aminopeptidase, acid phosphatase, and alkaline phosphatase activities were recorded. The esophagus showed two distinctive regions, the anterior with numerous mucous cells secreting acid mucins and the posterior with longitudinal folds and no mucous cells. The intestine was differentiated into three regions. The anterior showed goblet cells secreting acid and neutral mucins, while the middle and posterior regions presented goblet cells secreting only acid mucins. The activity of aminopeptidase, chymotrypsin, and amylase showed low levels, while the trypsin and acid phosphatase activity levels were intermediate. Lipase and alkaline phosphatase showed the highest activities. The results point that juvenile H. ingens presents a digestive structure similar to other teleost species. The high levels of lipase suggest that juvenile H. ingens have high requirements for lipids during this stage.

Age-related histochemical investigations of small intestinal goblet cells in bronze turkeys (Meleagris gallopavo gallopavo)

The aim of the study was to investigate the goblet cell types and their density in the small intestine of bronze turkey (Meleagris meleagris gallopovo), by means of Alcian blue-PAS staining. Sixty birds from 10 age groups were used. In the duodenum and jejunum, goblet cells produced acid, neutral and mixed mucins, while in the jejunum - acid mucins. A negative relationship was observed between cell density and either duodenum or jejunum lengths; such a correlation was not established in the ileum.

Morphology, histology and histochemistry of the digestive tract of the Banded tilapia, Tilapia sparrmanii (Perciformes: Cichlidae)

This study described anatomical, histological and histochemical features of the mucosal layer of the digestive tract of Tilapia sparrmanii Smith, 1840, an omnivorous freshwater fish endemic to Southern Africa. This species exhibited a short thick oesophagus with long deep longitudinal folds (466.68 ± 16.91 µm), and a thick (173.50 ± 10.92 µm) muscular layer that allow the passage of large food items. The mucosa was lined with stratified secretory epithelium rich in goblet cells that secreted neutral and acid mucins. The stomach was a sac-like structure with simple tubular glands surrounded by connective tissue. The mucosa was lined with simple columnar epithelium and the lamina propria exhibited a well-developed layer of gastric glands that occupied the entire length of the cardio-fundic region. The stomach mucosa consisted of epithelial cells with intense neutral mucin secretion which protects against gastric juice. Neck cells of gastric glands synthesized neutral and acid mucins. The intestine was highly coiled and presented a complex pattern of transversal folds internally (villi). Villi length decreased progressively from the anterior to the posterior intestine (p < 0.0001). Tunica muscularis of the mid-intestine had the thinnest thickness among all parts of the intestine (p < 0.0001). Goblet cells whose numbers increased towards the rectum secreted both acid and neutral mucins. The results indicate structural similarities of T. sparrmaniiGIT with other tilapia species and will be useful for understanding the physiology of the digestive systems as well as functional components of the GIT.

Histochemical Assessment of Mucin-Secreting Cells from the Gastric Mucosa of Guinea Pigs

Stomach fragments from 3 guinea pigs were collected from the three regions: cardiac, fundic and pyloric, for histochemical investigations. The anatomical segments were processed by the classical method of inclusion in paraffin and the histological sections were stained with PAS reaction for highlighting the neutral mucins and the Alcian blue method for acid mucins. All the surface cells of the gastric mucosa and in the crypts were positive on the PAS reaction and negative in the case of the alcian blue reaction. This demonstrates that cells on the surface and in the crypts synthetize neutral mucins. In the case of the cardiac region glands, only a small number of cells were positive on the two histochemical reactions, which shows that the cardiac glands in guinea pig synthesize a very small amount of neutral and acidic mucins. There are no positive cells in neither reaction used in the fundic glands case, which shows that these glands do not synthesize mucins, neither neutral nor acidic content. The glands located in the pyloric region have cells in the deep half of the wall which were positive on both histochemical reactions, which shows that they synthesize both neutral mucins and acidic mucins.

Hystometric evaluation of nickel chronic exposure effects on large instestine of adult Wistar male rats

The ingestion of considerable amounts of water or food contaminated with nickel can be very toxic. The present work was conducted aiming to evaluate the effects of nickel exposures on ascending colon of adult Wistar male rats at hystometric level. We used 12 animals that were divided in a control (ingested uncontaminated water) and a nickel-contaminated (i.e., 25 mg de nickel/L of water) groups. Nickel chloride was offered in declorinated water and the experiment had a 56 days exposure period. A portion of the ascending colon was removed of the animals and subjected to hystological labelling processes using blue toluidin (for general hystometric description), Alcian Blue (AB, for acid mucins) and periodic acid-Schiff (PAS) technique (for neutral mucins). The potential differences between groups were desgined by applying the Whitney test and t test (p < 0.05). The crypts were smaller for the nickel-contaminated group, even though these organism exhibited broader and higher crypts. Nickel-contaminated animals exhibited a smaller amount of calyceform cells with AB and PAS positive reactions as well as a less mucus quantities when compared with nickel-uncontaminated animals. Such reductions on the amount of calyceform cells with AB and PAS positive reactions may be related wiht the shallower crypts, which possibly reduced the synthesis and secretion of mucins, compromissing the functional aspects (e.g., lubrification and intestinal mucosa protection) of the nickel-contaminated large intestines. Interestingly, the wider and higher crypts and higher epithelium collumn on the nickel-contaminated animals may represent a relevant trade-off for the intestinal mucosa protection.

Histochemical evaluation of an epithelial layer of the cardiac part gastroesophageal junction mucosa in the different periods of a prenatal ontogenesis of human (part 2)

In order to study the quantitative and qualitative composition of mucins of the gastroesophageal zone (GEZ) epithelium during the stages of embryonic and fetal periods of ontogenesis, we conducted morphometric and histochemical studies of the epithelial differon of the gastroesophageal junction (GEJ). The early embryonic period of 5–6 weeks was established to have been observing a gradual increase of neutral and acid mucins secretion in the gastric parts of the GEJ epithelial differon whereas the embryo-fetal or non-fetal period from 7 to 9 weeks was characterized by changing and the structural rearrangement of the epithelial differon and sulfomucins appearance in gastric epithelium and gradual decrease in the production of acid mucins. The early fetal period (10–28 weeks) is characterized by disappearance of acid sialomucins in the enterocytes of the GEZ from 10 to 18 weeks and an increase to 7.65±0.18% of neutral mucins with a drop in their level in the 18-20 week period and a decrease to 24±0.10% at 28 weeks (p<0.001). The late fetal period, from 28 to 38 weeks, was characterized by a complete structural rearrangement of the epithelial differon of the GEZ with the formation of a simple columnar epithelium of the cardiac part of the stomach with incomplete histochemical cytological differentiation of the GEZ gastric epithelium. It was evidenced by the presence of residual acid mucins (sialomucins) that are not typical for mature gastric epithelium.

Histochemical evaluation of mucins distribution of the gastroesophageal zone esophageal epithelium in the embryonal and fetal periods of human ontogenesis (part I)

To study the quantitative and qualitative mucins profile of gastroesophageal zone (GEZ) epithelium during stages of the embryonal and fetal ontogenesis periods we have performed morphometrical and histochemical researches of the gastroesophageal junction (GEJ) epithelial differon. The current study was carried out on 169 human embryos and fetuses of gestational age from 4–5 till 38 weeks. It was established that during early embryonal period (5–6 weeks) gradual increase of neutral and acid mucins in esophageal part of the GEJ epithelial differon is observed. For early fetal period (10–28 weeks) disappearance of acid syalomucins in the GEJ enterocytes from 10 till 18 week and increasing of neutral mucin till 7,65±0,18% with falling of its level in 18–20 weeks period and decreasing till 2,4±0,10% in 28 weeks (р<0,001) was typical. Late fetal period from 28 till 38 weeks is characterized by complete structural rearrangement of epithelial differon of the GEZ stratified squamous nonkeratinized epithelium with formation of two functional zones: protective germinative in esophageal part of GEJ with incomplete histochemical cytodifferentiation of the GEJ esophageal epithelium. It was proved by remains of acid mucins (syalomucins) which are untypical for mature esophageal epithelium. Thus, the obtained data on the histological features of the GEZ epithelial differon in the prenatal period of ontogenesis will improve the accuracy of diagnosis and assessment of pathological changes in the mucous membrane of the GEJ.

COMPARATIVE HISTOCHEMICAL EVALUATION OF MUCINS EXPRESSION IN FETAL ESOPHAGUS AND ADENOCARCINOMAS OF THE GASTROESOPHAGEAL JUNCTION

Aim: To study and compare the expression patterns of mucins in the fetal gastroesophageal junction (GEJ) region and adenocarcinomas of the GEJ in adults using histochemical method. Material and Methods: To reveal the expression of different mucins, tissue sections from formalin-fixed paraffin-embedded tissue blocks of fetal GEJ and carcinomas of GEJ were stained by the following histological stains: hematoxylin and eosin, periodic acid-Schiff (PAS), alcian blue (AB), pH 2.5, combined AB-PAS, and combined AB-Aldehyde Fuchsin (AB/AF). Results: Expression of mucins within the developing fetal GEJ has been demonstrated (gestational age 5–38 weeks). We studied histochemical features of neoplastic cells in carcinomas of GEJ from 90 adult patients. The results showed that in gastric type expression of neutral mucins dominated especially in well differentiated (G1) adenocarcinomas and corresponded to the last three months of GEJ development, while in the intestinal and mixed type significant acid mucins expression was detected in moderate (G2) and poorly (G3) differentiated adenocarcinomas and corresponded to 17–25 weeks of GA. No significant coincidence in mucins expression was observed in signet ring cell carcinomas in relation to GA. Conclusion: Our data suggest that decrease of neutral mucins level can be considered reliable phenotypic marker of poor prognosis of GEJ adenocarcinomas. Study of the developmental expression of mucin genes may improve understanding of the malignant transformation of esophageal tissue.

Scleromyxedema (Arndt-Gottron Syndrome): a Case Report

Lichen myxedematosus, also known as papular mucinosis, is a primary diffuse cutaneous mucinosis. It is a rare cutaneous myxedematous condition characterized by formation of numerous lichenoid papules. Scleromyxedema, also known as Arndt–Gottron syndrome, is a rare, confluent, papular and sclerotic variant of lichen myxedematosus, characterized by diffuse thickening of the skin underlying the papules. The condition is associated with systemic, even lethal manifestations, fibroblast proliferation and accumulation of acid mucopolysaccharides of the hyaluronic acid. Serum IgG class paraproteinemia is always present and it can be detected in all patients if appropriate or even repeat testing is used. Herein, we present a 67-year-old patient with a 2-year history of skin problems. He had no health problems other than hypertension and diabetes, wich were both diagnosed 15 years before. On examination, the patient exhibited sclerodermoid lesions with diffuse pseudo-sclerodermatous thickening of the exposed skin, microstomia and sclerodactyly-like changes; on the face, there were numerous solid, shiny 2 - 4 mm in diameter skin-coloured lichenoid papules, scattered across the forehead, glabellar area, nasolabial folds, perioral region, ear lobes and the neck. Histopathological examination revealed: highly distinctive collagenosis and fibrosis in the middle dermis, increased fibroblasts; collagen bundles with irregular arrangement and fragmentation; alcian blue-positive deposits with appearance consistent with acid mucins. Serum protein electrophoresis detected IgG lambda paraproteinemia. The patient was treated with systematic corticosteroids during 9 months with subsequent introduction of methotrexate and showed satisfactory results. The etiology of scleromyxedema remains unknown, since the purified IgG paraprotein itself has no direct effects on fibroblast proliferation. In scleromyxedema, numerous therapeutic modalities are proposed, unfortunatelly with limited effects. In colclusion, we report a case of an adult male with lichenoid papules; after a two-year progression, they evolved into scleromyxedema and exhibited well response to conventional therapy.