Pancreatic duct obstruction in the pig: electron microscopy of chronic pancreatitis

Ultrastructural alterations of pancreatic tissues in growing pigs caused by surgical ligation of the main pancreatic duct are described. Five animals aged 6 to 7 weeks were operated on and necropsied 2, 6 or 8 weeks later. In addition, 3 pigs that were sham-operated served as controls. Obstruction of the ducts caused progressive luminal dilatations and rupture of intercellular connections of the epithelium followed by destruction and atrophy of acinar parenchyma and proliferations of immature ductular epithelial cells free from zymogen granules.     

Eurytrema procyonis in a New York fox

A fox infected with canine distemper virus had multiple Eurytrema procyonis trematodes within the major pancreatic duct. The ductal epithelium was slightly hyperplastic and there was mild periductal fibrosis present. There was dilatation of the pancreatic duct containing the parasites. Numerous eosinophilic intracytoplasmic inclusions were present in the epithelium of multiple organs, including the pancreatic ducts.     

Immunocompetent cells in avian paraocular glands

A study was made of the Harderian and lachrymal glands of fowls, pheasants, turkeys and pigeons. Accumulation of heterophils and plasma cells commenced soon after hatching, was well advanced by four weeks of age and was always greater in the Harderian than in the lachrymal glands. Plasmablasts entered via interlobular capillaries, maturing as they migrated to and congregated round the lobular collecting ducts. Their secreted immunoglobulin was readily demonstrated in the duct lumen. Russell body containing cells of diverse morphology were a consistent feature of infiltrated Harderian glands. Though scant in the glands proper, lymphoid tissue was abundant in the walls of their draining ducts.     

秦岭细鳞鲑消化系统的形态学观察

运用大体解剖和常规组织学方法对秦岭细鳞鲑消化系统的组织形态进行了系统观察。结果表明,秦岭细鳞鲑的消化道由口咽腔、食道、胃和肠等4部分组成,除口咽腔外,管壁由内向外分为黏膜、黏膜下层、肌层和浆膜。口咽腔宽大,上颌、犁骨及腭骨等处布有细齿,黏膜衬以复层扁平上皮,间有较多的黏液细胞和少量的杯状细胞及味蕾;食管粗而短,黏膜向管腔突出形成多个纵行皱襞,上皮由复层扁平上皮逐渐向单层柱状过渡,上皮细胞间可见到数量较多的粘液细胞和杯状细胞,食管腺不发达;胃体积较大,呈“U”形,包括贲门部、胃体和幽门部,胃体部小凹及胃底腺结构明显,肌层发达;胃与肠相接处有63-65个幽门盲囊,肠道粗短而略微盘曲,黏膜上皮为单层柱状,未见明显的肠腺。以上结果显示,秦岭细鳞鲑消化道组织结构与其肉食性功能密切相关。肝小叶界限不清;双列肝细胞围绕中央静脉呈放射状走行,肝细胞个体大、呈多边形,核呈圆形或卵圆形,1-2个。胰脏大部分环绕前肠边缘、呈细长条索状,另可见分散于幽门盲囊及胃周围的弥散部分;其外分泌部为管泡状腺,腺细胞呈锥体形,胰岛结构明显。     

Ultrastructural study of sheep lacrimal glands.

Sheep lacrimal glands are mixed glands, consisting of tubulo-acinar units succeeded by ducts of simple morphology. The secretory portions consist of three cell types: mucous, seromucous and serous, which may be intermingled in the same acinus or may form acini wholly made of only serous or mucous cells. Mucous cells show a rough endoplasmic reticulum that is reduced to a few cisternae located near the cell base and among the interstices of the secretory droplets. Mucous granules appear uniformly electron-lucent. Serous cells display a typical structure; serous granules can be uniformly electron-dense or composed of dense inclusions dispersed in an electron-lucent matrix. The seromucous granules have a bizonal substructure: a dense core is embedded in a highter matrix. Secretory acini are succeeded by intercalated ducts; the epithelium of these ducts gradually increases in height to form a kind of excretory duct, without the intervention of striated ducts.     

Microscopy of the echidna sublingual glands

The secretory units and duct system of the echidna sublingual glands exhibit subtle architectural modifications to accommodate the viscous secretion produced by these glands. The glands are compound tubular glands, the secretory units of which are elongate with open lumina and consist only of mucous cells. Closely packed spindle-shaped myoepithelial cells invest the secretory units, but are absent around the ducts. The branched secretory tubules open into an abbreviated duct system characterized by wide lumina. Striated ducts normally associated with the second portion of the intralobular duct system are absent. The duct system shows the most obvious modification of general salivary gland architecture presumably to accommodate the viscous secretion propelled from the secretory units by surrounding myoepithelial cells.     

Light and electron microscopical observations on the terminal airways and alveoli of the lung of the SA (Cape) fur seal Arctocephalus pusillus

During activities of the Sea Fisheries Research Institute at Kleinzee, lung samples from six South African fur seals were collected. The terminal airways showed pseudostratified ciliated columnar epithelium with numerous goblet cells and occasional brush cells. Smooth muscle, cartilage and submucosal glands were also present. The epithelium changed over a short distance, in the smaller airways, through pseudostratified columnar non-ciliated to simple cuboidal epithelium with no goblet cells. The columnar non-ciliated cells contained secretory granules, which appeared to be serous. No Clara cells were found. Cartilage and muscle were present throughout, up to the origin of the alveolar ducts, but the glands disappeared together with the goblet cells. Alveoli were lined by types one and two alveolar epithelial cells, with subepithelial capillaries. They were divided by an alveolar septum with a well developed alveolar knob. This knob contained elastic fibres and fibroblasts, but not the smooth muscle cells which are present in terrestrial mammals and in Phocidae.     

Expression of the sweet receptor protein, T1R3, in the human liver and pancreas

The expression of T1R3, a taste receptor essential for the perception of sweetness and umami-taste, was examined by immunohistochemistry to determine whether and where it may be localized in the liver and pancreas. In the liver, both immunopositive and immunonegative reactions were detected; bile ducts and intercalated portions of the bile ductules were immunopositive to T1R3, while arterioles and venules were immunonegative in interlobular connective tissue. In the hepatic lobule, all other cells including liver cells (hepatocytes) and bile capillaries were immunonegative. In the pancreas, all endocrine portions of the pancreas were immunonegative to T1R3. Within the exocrine portions, immunopositive reactions were detected in excretory duct cells, intercalated cells, and centroacinar cells. In contrast, acinar cells were immunonegative, as were vessels, lymph capillaries, nerve fibers, and connective tissue cells in the exocrine portions. The restricted localization of T1R3 in the duct cells of the liver and pancreas in the present study may indicate that T1R3 is involved in monitoring changes in the makeup of bile and pancreatic juices in the hepatic and pancreatic duct systems.     

Spontaneous Ameloblastic Fibroma in a Young Guinea Pig

A spontaneous ameloblastic fibroma was found in a 9-week-old guinea pig. Histopathologically, neoplastic cells consisted of two components: an odontogenic epithelium and odontogenic mesenchyme. The odontogenic epithelium formed strands, nests and islands that were interspersed within the odontogenic mesenchyme. In the marginal region, odontoblasts and scant dysplastic eosinophilic material were seen between these two components. Immunohistochemically, the odontogenic epithelium was positive for cytokeratin AE1/AE3, and the odontogenic mesenchyme and odontoblast were positive for vimentin, in the same manner as in the normal tooth germ (control). We could not obtain conclusive data suggesting that the eosinophilic material was dental hard tissue because the eosinophilic material was not stained specifically by any methods. Based on these histological characteristics, the tumor in the present case was diagnosed as an ameloblastic fibroma. This is the first report of ameloblastic fibroma in guinea pigs.     

Inhaled feed particles in experimental pigs with and without vitamin A deficiency.

An attempt was made to experimentally reproduce an unusual respiratory disease of pigs fed a dusty mixture of finely ground peas, wheat, and barley. Groups of vitamin-A-deficient piglets from this herd were either given dry feed and daily exposure to dust from the feed or were given wet feed. Vitamin-A-fortified pigs of another stock were also given the dry feed and dust exposure. The upper and lower respiratory tracts, renal pelves, and interlobular ducts of salivary glands were studied histologically. The distinguishing features of lungs were starch particles from feed (up to 31.2 mum in diameter) in all lungs (but more in lungs of pigs given dry feed), free alveolar macrophages, giant cell formations, and mild degenerative processes of respiratory epithelium. The epithelium of most renal pelves was marked by mucinous degeneration.     

Seasonal variations in the morphology of the seminal vesicles of the African straw-coloured fruit bat (Eidolon helvum)

The study investigated seasonal changes in the morphology of the seminal vesicles of Eidolon helvum in a typical African tropical environment. Seminal vesicles of forty-eight bats were examined during the early rainy, late rainy and peak dry seasons, using gross anatomical, histological and ultrastructural techniques. The interlobular connective tissue septa from the external capsule demarcated the glandular parenchyma into numerous lobules of tubulo-alveolar glands. A simple cuboidal epithelium of mono- or bi-nucleated cuboidal cells lined the glandular mucosa during the rainy season. This was replaced by a bistratified cuboidal epithelium, whose upper layer of cells showed evidence of degeneration, during the dry season. The PAS-positive secretory products appeared to be numerous during the rainy season, but few and clumped together during the dry season. The mean gross weight, interlobular septal thickness, acini diameter and epithelial height of the glands varied significantly with season. Ultrastructural features of the secretory cells during the rainy season showed well-developed cytoplasmic organelles, numerous electron lucid secretory vesicles and electron-dense granules. Secretory epithelial cells of the seminal vesicles are very active during the rainy season, while regeneration of degenerated epithelium in preparation for the next reproductive cycle occurs during the dry season.     

Immunohistochemical and scanning electron microscopic comparison of the collagen network constructions between pig, goat and chicken livers

The distribution and three-dimensional architecture of collagen fibers were compared between pig, goat and chicken livers. Immunohistochemical staining revealed that collagen type I was identified in the interlobular connective tissue region and intralobular areas in pigs and goats. Type III collagen was also identified in the interlobular connective tissue region and intralobular sinusoidal walls. In the chicken liver, only the circumference region of the vessels was immunostained with collagen type I and III antibodies and the interlobular connective tissue wall could not be distinguished clearly. In the intralobular region, collagen type I antibody immunoreacted around the hepatic cells but collagen type III antibody immunoreacted weakly. In the NaOH macerated specimen, well-developed collagen bundles formed the prominent interlobular walls in pigs. In contrast, the wall in the goat liver comprised a thin layer of the bundles. In the chicken liver, there were no notable collagen septa between lobules. The intralobular collagen construction was quite different between the animals, indicating a fragile collagen fibril networks in pigs, a robust framework in goats and dense fabric-like septa in chickens. These results indicate that the distinct collagen frameworks may contribute to the histological strength of the livers in each of the animal species.     

Investigations on the conjunctival goblet cells and on the characteristics of glands associated with the eye in the guinea pig

Objective To investigate the distribution and density of conjunctival goblet cells (GC) and to study the anatomy and microscopic characteristics of glands associated with the eye in the guinea pig. Procedures Twenty‐five guinea pigs were used. Meibomian gland openings were counted using biomicroscopy. Conjunctiva, eyelids and glands were embedded in glycol methacrylate and paraffin. Sections were stained with hematoxylin and eosin (H&E), periodic acid Schiff’s reaction (PAS) and Alcian blue (AB). Results Highest GC densities were found in the bulbar and palpebral region of the nasal conjunctiva (GC index: 13.7–16.4%). Lowest GC densities (GC index: 0.0–1.0%) were found in 3/4 limbal regions (nasal and temporal upper eyelid, temporal lower eyelid). Guinea pigs have 27.1 ± 3.0 (mean ± SD) meibomian gland openings in the upper lid and 25.7 ± 2.3 in the lower lid. Difference between upper and lower lid was significant (P = 0.037). Two subconjunctival sebaceous glands occur temporal to each eye. The Harderian gland is very large. In the lacrimal gland three different cell types were distinguished both according to the cell structure and histochemical staining. Conclusions Goblet cell densities are lower in guinea pigs than in dogs and horses. Positive staining with PAS and AB could be an indication that mucins are produced in the lacrimal gland. If so, they may contribute to the mucin layer of the tear film. Both the extraordinarily large Harderian gland and the subconjunctival sebaceous glands produce lipids and may contribute to the lipid layer of the tear film.     

Gender Differences in the Anatomy of the Perineal Glands in Guinea Pigs and the Effect of Castration

Perineal glands in guinea pigs are part of the sebaceous glandular complex. Their secretions are used for scent marking. This is important for social status and can be seen in both sexes and castrated males. Discrepancy exits about the existence of these glands in female guinea pigs and knowledge of the anatomical consequences of castration on the male perineal glands is sparse. To examine these uncertainties related to gender, perineal glands from 13 sexually mature pet guinea pigs were examined macro‐ and microscopically. Clear gender differences in the anatomy of perineal glands were found, and castrated males showed signs of atrophy and fatty infiltration in the glands. Females do have perineal glands, although smaller than the glands in the male. The glands are typically sebaceous with multiple excretory ducts. A macroscopic unique feature in the males was the clearly evident orifices of a large excretory duct on each side of the slightly everted perineal sac. However, the reason for this gender difference is not clear. In castrated males, the orifices were atrophied and difficult to see. In addition, the sebaceous glands of the hair follicles in the skin folds of the perineal opening were smaller and less abundant in females and castrated males. The changes in castrated males are presumably linked to the hormonal changes and decreased secretion after castration. The dense keratin layer in the perineal sac was thicker in males than in both castrated males and females and could contribute to the concrement formation seen mainly in males.     

不同品种和年龄牛胆囊的比较组织学研究

通过对八例健康黄牛和健康小牛胆囊的比较组织学观察，我们发现，牛胆囊中以颈部粘膜皱臂明显，体部渐平坦，底部最少。粘膜上皮为单层柱状上皮，内有少量杯关细胞，大部分胆囊可见有淋巴滤泡，但是在血管周围未见淋巴和异染细胞的浸润，证明滤泡的形成与胆囊感洒无关。这种淋巴滤泡在黄牛胆囊中较多，水牛胆囊仅见一例。在黄牛和水牛胆囊中，均有腺体存在，黄牛的腺体明显多于水牛。腺体分为浆液腺、粘液腺和混合腺。老龄牛胆囊中腺     

雌性空怀双峰驼生殖道的形态结构

应用组织学方法观察了雌性空怀双峰驼生殖道的形态结构。结果显示，双峰驼生殖道的基本结构与其他哺乳动物相似，但微细结构有差异。双峰驼输卵管粘膜皱襞极其发达，分支多而呈复杂的网状迷路。皱襞基部的迷路酷似固有膜而存在腺体，迷路网格内常见细胞团块。虽然双峰驼怀孕时胎儿位于左侧子宫角，但左、右子宫角以及子宫体的组织结构基本相同。子宫内膜无肉阜，上皮下陷于固有膜内，形成大量长而弯曲的单管状腺。子宫颈固有膜浅层分布有许多小腺体，深层分布有成群的较大腺体。这些腺体为分支管状腺，腺上皮PAS强阳性。阴道粘膜上皮为复层上皮。从输卵管到阴道，粘膜上皮主要为单层柱状上皮，由纤毛细胞和分泌细胞组成，局部可见假复层柱状纤毛上皮。纤毛细胞由前向后逐渐减少，但在子宫颈仍可见到。粘膜上皮和腺上皮内夹有许多淋巴细胞或中性粒细胞，后段局部甚至见到这些免疫细胞浸润于上皮细胞间。固有膜内分布有大量淋巴细胞、中性粒细胞、肥大细胞、浆细胞和巨噬细胞，有时出现淋巴滤泡。     

Histochemical and surface ultrastructural characteristics of the nasal cavity of laughing dove

Ten apparently healthy, adult laughing doves were used to document detailed histological, histochemical and surface ultrastructural features of the nasal cavity and to investigate the structure‐function relationship of the nasal cavity in this species. We observed that the nasal cavity of the laughing dove was composed of three main regions: nasal vestibule, respiratory and olfactory. Each region presented a characteristic epithelial lining. The epithelium varied along the nasal vestibule from keratinized stratified squamous rostrally to non‐keratinized stratified squamous in the middle and stratified cuboidal in the caudal region of the nasal vestibule. The respiratory region was lined with pseudostratified columnar epithelium and was initially devoid of both goblet cells and cilia, but cilia then appeared and increased gradually in number close to the olfactory region. The caudal part of the respiratory region presented a stratified cuboidal epithelium. Strong alcianophilic, intra‐epithelial mucous glands were identified, starting at the caudal region of the nasal vestibule and extended into the respiratory region. The olfactory region was lined with a pseudostratified epithelium that consisted of three different cell types: olfactory, support cells and basal cells. In conclusion, the current investigation presents new information concerning the histological, histochemical and ultrastructural features of the laughing dove's nasal cavity. Furthermore, the findings of this study may prove to be a valuable contribution to the avian histology and pathology literature.     

Histological Structure and Distribution of Carbonic Anhydrase Isozymes (CA‐I,II, III and VI) in Major Salivary Glands in Koalas

While the mandibular glands usually consist of only mucous acinar cells or a combination of mucous and serous cells in other species of mammals, those of koalas were serous glands. Rabbit mono‐specific polyclonal anti‐canine CA‐I, II, III or VI antiserum showed cross‐reactivity against corresponding koala carbonic anhydrase (CA) isozymes. Although immunohistochemical reactions to CA‐I, II and VI in ductal cells were moderate to strong in the tested salivary glands, no reaction or only slight reactions were observed against CA‐III. In the sublingual glands, moderate immunohistochemical reactions to CA‐I, II and VI were also evident in serous acinar cells and serous demilunes. However, no reactions to the tested isozymes were observed in mucous acinar cells in these glands. With the exception of the histological structure of the mandibular glands, histological features and the distributional profile of CA isozymes of the salivary glands in koalas are relatively close to results obtained from horses.     

The Presence of Granular Excretory Ducts in the Rabbit Zygomatic Gland

The proximal and interlobular ducts of rabbit zygomatic glands show a particular morphological feature consisting of numerous secretory granules localized in the apical cytoplasm of the cells. It is suggested that there is a similarity between these ducts and the granular ducts of submandibular glands in rodents.     

Immunohistochemistry of carbonic anhydrase isozymes (CA-I, II and III) in canine salivary glands: a distributional and comparative assessment

The immunohistolocalization of carbonic anhydrase isozymes (CA-I, II, III) in canine salivary glands was studied using antiserum against CA-I, II, III. In parotid glands, immunostaining intensely localized cytosolic CA-II antiserum throughout the cytoplasm of acinar secretory cells and ductal epithelial cells, especially in the striated duct region. CA-III reactivity in the glands was only seen selectively at the intercalated ductal cells. In contrast, no immunoreaction localized CA-I in the gland. In the submandibular and sublingual glands, CA-I, II, and III were all observed in the ductal segments of the glands, whereas serous demilune appeared devoid of all three cytosolic CA isozymes. In contrast, in zygomatic glands (i.e. dorsal buccal glands) all CA isozymes were observed in both serous demilune and ductal segments. In all of the salivary glands examined, no mucous acinar cells were found to be reactive for any CA.