Scanning Electron Microscopy of the Orbital Harderian Gland in the Male Atlantic Bottlenose Dolphin (Tursiops truncatus)

The ultrastructure of the Harderian gland of Atlantic bottlenose dolphin ( Tursiops truncatus ) was examined by scanning electron microscopy (SEM). We found the following surface features: the typical round appearance of the ascinar glandular unit with a finely granular surface, a thin cortex and immediately below two types of cells: type I cells (characterized by small lipid vacuoles) and type II cells (characterized by large lipid vacuoles). It has been suggested that different cells forms represent a single cell type in varying activity states. Additionally, a coalescent tubular complex, a small balloon-like structures and large globular structures were observed. These structures may be reservoirs of secretion products.     

Structure of bovine fungiform taste buds and their immunoreactivity for gustducin

The taste buds of bovine fungiform papillae were studied by light and electron microscopy using both histological and immunohistochemical methods. The taste buds existed in the epithelium of the apical region of the papillae. By electron microscopy, two types of taste cells, namely type I and type II cells, could be classified according to the presence of dense-cored vesicles, the cytoplasmic density and the cell shape. Type I cells were thin, had an electron-dense cytoplasm containing dense-cored vesicles, and possessed long thick apical processes in the taste pore. Type II cells were thick, had an electron-lucent cytoplasm containing many electron-lucent vesicles, rather than dense-cored vesicles, and possessed microvilli in the taste pore. Immunohistochemical staining with an antiserum against gustducin was investigated by both light and electron microscopy using the avidin-biotin complex (ABC) method. Some, but not all, of the type II cells exhibited gustducin immunoreactivity, whereas none of the type I cells showed any immunoreactivity.     

Isolation and differentiation of bovine mammary gland progenitor cell populations

OBJECTIVE: To isolate bovine mammary gland cells with stem cell characteristics. SAMPLE POPULATION: Monolayers of bovine mammary gland cells. PROCEDURE: Mammary gland cell populations were separated by use of selected media supplements. Phenotypic characteristics were examined via light and transmission electron microscopy. Cellular expression of casein and connexin 43 was identified immunohistochemically. A scrape-loading and dye transfer assay was used to examine the mammary gland cell populations for homogenous gap junctional intercellular communication (GJIC). RESULTS: Subpopulations of mammary gland cells grown in vitro are classified on the basis of their distinct morphologic features and ability to communicate via gap junctions. Ultrastructurally, 2 morphologically distinct cell types were classified as type I and II cells. Type I cells were small light undiffertiated cells and large light undifferentiated cells that were deficient in functional gap junctions (as is characteristic of stem cells). Type II cells included large light differentiated cells and terminally differentiated cells; GJIC was functional in type II cells. Type II cells had cytoplasmic expression of connexin 43, whereas, type I cells did not. All cells expressed casein. CONCLUSIONS AND CLINICAL RELEVANCE: Subpopulations of bovine mammary gland cells with stem cell characteristics were identified. Phenotypic differences are observed among type I bovine mammary gland cells with stem cell characteristics. Gap junctional intercellular communication may be necessary for the differentiation of stem cells. Characterization of bovine mammary gland stem cells and their progeny may provide a new tool with which to study mammary gland health.     

The fine structure of the Harderian gland in the ostrich (Struthio camelus)

The Harderian gland of the ostrich (Struthio camelus) is a tubuloalveolar gland containing holocrine secreting epithelial cells. The gland epithelium is composed of two different cell types, which can be classified as type I and type II. These cells contain dense secretory vesicles in their cytoplasm and they are connected laterally with desmosomes. At the basal site of these cells, myoepithelial cells are present. Plasma cells are observed in the subepithelial region of the gland. In the interlobular trabeculae, forming the gland stroma, fibroblasts, blood vessels and nerve fibres are included. Another important finding in the ostrich Harderian gland is the presence of homogeneous material.     

Ultrastructure of the Carotid Body of the Goat

The carotid body of the goat was found to be a small oval or rounded parenchymatous organ. It was characterized by its profound vascularity. Delicate septa divided the parenchyma into small feebly denned lobules. Electron microscopy revealed that the parenchyma comprised type I cells, type II cells, nerve endings, axons and fenestrated dilated capillaries. Type I cells were characterized with electron dense-cored vesicles. They showed variations in size and concentration of the dense-cored vesicles and number of mitochondria. The possibility that these variations are reflections of different stages of activity is discussed. Type II cells were less numerous than type I cells, relatively small and devoid of dense-cored vesicles. They usually surrounded small groups of type I cells and associated nerve endings and axons. Presumptive afferent nerve endings characterized with many clear vesicles, occasional large granular vesicles and varying numbers of slender mitochondria, lay apposed to type I cells. Nerve endings of this kind showed afferent and efferent synaptic junctions with type I cells. Presumptive sympathetic efferent endings were occasionally seen within the lobules but never lay apposed to type I cells or afferent nerve ending.     

Hematopoietic prostaglandin D2 synthase in the chicken Harderian gland

The Harderian gland (HG), a sero-mucous secreting organ in the eye orbit, has long been recognized as immunologically important in chickens. During experimentation to characterize immune components of the gland, proteomics analysis revealed the presence of hematopoietic prostaglandin D synthase (H-PGDS). Extraction of total RNA followed by RT-PCR produced cDNA of 597 base pairs. DNA sequencing revealed nucleic acid and predicted amino acid sequences that were 99% aligned with the one published sequence for chicken H-PGDS of the spleen. Alignment with murine, rat, and human H-PGDS were 69, 69, and 66%, respectively. Ocular vaccination of chickens with a Newcastle Disease/Infectious Bronchitis vaccine (Mass.-Ark. Strain) induced an increase in H-PGDS expression determined by real-time PCR. Furthermore, immunohistochemistry of frozen HG sections showed positive stained cells for both H-PGDS and mast cell tryptase in the sub-epithelial cell layers of the HG ducts. Based on the potent vasoactive role of PGD(2), it appears that the chicken HG is a site of active mucosal immunity partially mediated by PGD(2) synthesized by H-PGDS in the gland.     

Structural and ultrastructural characteristics of interrenal gland and chromaffin cell of matrinxã, Brycon cephalus Gunther 1869 (Teleostei-Characidae)

This work presents the structure and ultrastructure of the interrenal gland and chromaffin cells, as well as the morphology of the head kidney of Brycon cephalus. The head kidney is composed of fused bilateral lobes located anterior to the swim bladder and ventrolateral to the spinal column. The parenchyma revealed lympho-haematopoietic tissue, melano-macrophage centres, interrenal gland and chromaffin cells. The interrenal gland consisted of cords or strands of cells grouped around the posterior cardinal vein and their branches. Chromaffin cells are found in small groups, closely associated with the interrenal gland and/or under the endothelium of the posterior cardinal vein. So far, the ultrastructural analysis has revealed only one interrenal cell type which contained abundant smooth endoplasmic reticulum and numerous mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Two types of chromaffin cells were observed. The first type was characterized by the presence of vesicles with round, strongly electron-dense granules, which were eccentrically located. Such cells were interpreted as noradrenaline cells. Meanwhile, cells which contained smaller vesicles and electron-lucent granules, with a small halo separating the granule from the vesicular limiting membrane, were identified as adrenaline cells.     

Retrospective – systematic study and quantitative analysis of cellular proliferation and apoptosis in normal, hyperplastic and neoplastic perianal glands in dogs

Neoplasms in the perianal region are frequently diagnosed in dogs. The aetiology is unknown, and most of them are benign. In this study, 240 neoplasms of the perianal glands of dogs were retrieved from the Department of Pathology archives of the Faculty of Veterinary Medicine and Zootechny of University of São Paulo (FMVZ/USP), from 1984 to 2004. All 240 cases were re‐examined by two pathologists. Nine cases (4%) were diagnosed as hyperplasia, 49 (20%) as group I adenoma, 81 (34%) were classified as moderately differentiated adenomas of the group II, 46 (19%) were poorly differentiated adenomas of group II, 48 (20%) were carcinoma of the group III according to the classification proposed by Berrocal, and 7 (13%) were other kind of tumours. Males over 8 years of age were predominantly affected. Cell proliferation was quantified by counting proliferating cell nuclear antigen (PCNA) positive nuclei, and apoptosis was quantified by counting fluorescent eosin‐stained apoptotic corpuscles (AC) in normal tissue, hyperplasia and in different histologic types of neoplasia of these glands. A parallel pattern of increase in both parameters (cell proliferation and apoptosis) was obtained. The net growth index (NGI), represents how much a cell population is proliferating or dying and was achieved by dividing the mean PCNA count in 1000 cells by the mean AC stain count in 1000 cells. NGI was different between hyperplasia and neoplasia; group I adenomas have a much higher potential of growth, and NGI decreases from benign towards malignant lesions. These results show up the importance of studying cell proliferation and apoptosis to understand the carcinogenesis of dog perianal gland.     

Histological Structure of the Adrenal Gland of the Bottlenose Dolphin (Tursiops truncatus) and the Striped Dolphin (Stenella coeruleoalba) from the Adriatic Sea

The structure of the adrenal gland was studied in 11 bottlenose dolphins ( Tursiops truncatus ), and five striped dolphins ( Stenella coeruleoalba ). These species are legally protected in Croatia. All examined animals died of natural causes and were found stranded along eastern Adriatic coast. In both species the adrenal gland consists of a cortex and a medulla; the cortex is divided into three zones. Whereas in the bottlenose dolphin, there is a zona arcuata which contains columnar cells arranged in the form of arches; in the striped dolphin this zone is replaced by zona glomerulosa containing rounded clusters of polygonal cells. In both species, the zona fasciculata consists of radially oriented cords of polygonal cells, whereas in zona reticularis cells are arranged in branching and anastomosing cords. The adrenal medulla in both species contains dark, epinephrine-secreting cells and light norepinephrine-secreting cells. Epinephrine-secreting cells are localized in the outer part of the medulla, whereas norepinephrine-secreting cells are found in the inner part, arranged in clusters and surrounded by septa of thin connective tissue. The gland is surrounded by a thick connective-tissue capsule, from where thick trabeculae extend towards the interior. In the bottlenose dolphin, group of cells resembling both medullar and cortical cells can be seen within the capsule; whereas only groups of cells resembling cortical cells are found within the capsule of the striped dolphin. In the bottlenose dolphin invagination of the adrenal cortex into the medulla is obvious as well as medullary protrusions extending through cortex to the connective tissue capsule.     

The Bovine Luteal Histological Composition: A Topographic Point of View

High‐yielding dairy cows are struggling with a high incidence of embryonic loss, among others caused by an insufficient peripheral progesterone concentration which for its part might be associated with an impaired luteal progesterone production. This impaired capacity to produce progesterone might be reflected in the histology of the gland. The aim of the present pilot study was the assessment of the variation in cell density within a bovine luteal gland (LG), to examine whether it is possible to analyse histologically the functionality of the gland based on one single tissue sample. Six LGs (stage II or III) were harvested out of just as many healthy cows at the slaughterhouse. The luteal cell density was assessed by calculating the nuclear density (ND) of the different luteal cell types on haematoxylin‐eosin‐stained histological sections from a number of topographic regions evenly spread throughout the glands, to give an overview of the pattern of cellular distribution within the whole gland. Cells were differentiated into ‘large luteal cells’, ‘small luteal cells’ and ‘non‐steroidogenic cells’. Results show that the cellular density, within a tissue sample is not significantly influenced by its location in relation to the gland's equatorial plane. However, the position with respect to the polar axis of the gland has a decisive effect, as the ND is significantly higher (p < 0.05) in the peripheral regions (outer zone) when compared with the central regions (inner zone) of the gland, and this counts for all three cell types.     

miR-138对小鼠乳腺发育及泌乳功能的影响

microRNAs(miRNAs)在各种类型细胞增殖、分化和凋亡中发挥了重要作用。miR-138参与乳腺发育周期过程中细胞增殖分化的调控。试验以小鼠为动物模型,尾静脉注射miR-138基因抑制剂,应用幼鼠体重称重法,检测miR-138抑制后乳腺泌乳量变化;应用电子显微镜等技术观测乳腺组织形态变化,抑制miR-138后,小鼠乳腺上皮细胞增加,乳汁分泌量增加;抑制miR-138后,观察小鼠乳腺组织超微结构可发现,乳腺细胞的代谢活动增强;收集尾静脉注射miR-138 抑制剂的小鼠乳汁,检测发现其乳糖、乳中酪蛋白含量均有所增高。研究认为,miR-138可刺激乳腺上皮细胞增殖,增加乳腺发育泌乳过程中乳的分泌,并且调控乳汁中重要成分含量。     

Topographic Distribution of the Different Cell Types,Connective Tissue and Vascular Tissue/Lumina Within a Functional Bovine Corpus Luteum and its Association with Breed,Type of Fixation Protocol and Stage During the Cycle

In the present study, we analysed the effect of fixative, breed, luteal stage and location on the nuclear density, volume density of connective tissue and vascular tissue/lumina within a bovine luteal gland in view of the development of an in vivo sampling technique to longitudinally monitor luteal histophysiology. The inner zone defined as the zone geometrically closest to the centre of the gland shows a significantly lower nuclear density (for all cell types) and a higher volume density of collagen fibres and vessels when compared with the outer zone (p < 0.001). The nuclear density in luteal glands from Holstein‐Friesian cows is not significantly different from that in Belgian Blue cows, nor is it in stage II vs stage III glands. The collagen fibre content was significantly lower in glands of Belgian Blue cows (p = 0.01) and in younger glands (p = 0.003). Hence, it seems that the lower nuclear density in the inner zone was compensated by a higher amount of collagen fibres. As the type of fixative applied has a significant effect on the nuclear density of the different cell types, the present study warrants future research to further optimize the fixation protocol. As a conclusion, we can state that the topographic difference in nuclear distribution for the different cell types in a bovine luteal gland is only significant when comparing the inner vs the outer zone. This implies that if a sample representative for the whole gland has to be taken, for example, when taking an in vivo sample, it is necessary that the biopsy goes through the inner zone and contains the total diameter of the gland.     

日粮能量对乌鸡外周血清促性腺激素与垂体分泌促性腺激素的影响

采用体外细胞培养和放射免疫测定法（RIA）测定日粮能量对鸟鸡外周血清促性腺激素与垂体分泌促性腺激素的影响。日粮能量处理：低能Ⅱ组、低能I组、对照组、高能I组、高能Ⅱ组;体外培养垂体细胞组分：高能组、对照纽、低能组。结果显示,血清中FSH含量,对照组与高能Ⅱ组相比差异显著（P〈0．05）,与低能I、Ⅱ组相比差异极显著（P〈0．01）;血清中LH含量,对照组与高能I组、高能Ⅱ组组间差异显著（P〈0．05）;低能Ⅱ组与高能I组、低能Ⅱ组与高能Ⅱ组、低能I组与高能I组、低能I组与高能Ⅱ组组间差异极显著（P〈0．01）;单层垂体细胞中FSH含量,高能组和对照组与低能组比差异显著（P〈0．05）;单层垂体细胞中LH含量,高能组与低能组比较差异极显著（P〈0．01）,对照组与低能组比较差异不显著。结果表明,日粮能量对处理体外培养乌鸡垂体细胞分泌FSH、LH有促进作用。     

Role of the harderian gland in immunoglobulin A production in chicken lacrimal fluid

The role of the Harderian gland (HG) in the production of immunoglobulin, especially IgA, was investigated. Lacrimal immunoglobulin almost disappeared after surgical removal of the HG and immunoglobulin produced by HG cells was detected in saliva but not in the trachea. Immunoglobulin production occurred in HG cell culture in vitro and it consisted mostly of IgA; the production of IgM and IgG was very low. These findings indicate that lacrimal IgA is produced locally in the HG and lacrimal IgG and IgM are mostly transported from the blood.     

Light and electron microscopic study of the thyroid gland of the camel (Camelus dromedarius)

The thyroid gland of sexually immature dromedary camels was studied using both light and electron microscopy. The thyroid gland contained follicles of different sizes in both summer and winter. However, most of the follicles were large in summer and small in winter. The large follicles were lined by very low cuboidal or semi-squamous follicular cells whereas the small ones were lined by high cuboidal or low columnar follicular cells. Electron microscopy showed that the very low cuboidal follicular cells were poor in organelles and were considered hypoactive. High cuboidal follicular cells on the other hand, were rich in organelles that included mitochondria, cisternae of rough endoplasmic reticulum, secretory vesicles, colloid droplets, heterosomes and autophagic vacuoles; they were considered to be very active. The possible role played by these organelles is synthesis of thyroglobulin and liberation of tri- and tetraiodothyronine is discussed. A few degenerate follicular cells were infrequently encountered in the camel thyroid. Parafollicular (C) cells were not seen in this study either with light or electron microscopy.     

Characterization of bovine haemopoietic progenitor cells using monoclonal antibodies and fluorocytometry

Monoclonal antibodies against bovine leucocyte cell surface differentiation antigens were used in combination with a fluorescence activated cell sorter to enrich bovine haemopoietic progenitor cells present in bone marrow cell populations prior to in vitro culture. After two sequential centrifugations of the bone marrow cell suspension through Ficoll-Paque, the interface fraction was stained with a cocktail of monoclonal antibodies directed against mature monocytes/macrophages, granulocytes and lymphocytes. Using appropriate electronic window settings on a FACStar Plus, cells with a high 90 degrees light scattering property (granular cells), a low forward light scattering property (erythrocytes and reticulocytes) and cells positive for monoclonal antibodies specific for lineage-restricted leucocyte markers were removed and the negative cell fraction collected. These negatively-selected cells were stained with monoclonal antibodies specific for a pan-leucocyte or a MHC class II marker and the positive cell population was collected in a second sort and subsequently submitted to culture. All erythroid and granulocyte/macrophage colony forming cells expressed MHC class II antigens, as well as the pan-leucocyte antigen. These same progenitors did not bind any of a variety of monoclonal antibodies directed against lineage-specific antigens on lymphocytes, granulocytes or monocytes/macrophages, although they did bind monoclonal antibodies recognizing MHC class I antigens. Between 85% and 91% of the isolated cells seeded were capable of forming erythroid or granulocyte/macrophage colonies within 5 to 10 days, thus increasing the plating efficiency of these cell types in bone marrow populations by at least 60 fold.     

Flow cytometric evaluation of ki67 for the determination of malignancy grade in canine lymphoma

Ki67 is a nuclear antigen significantly correlated with degree of malignancy in human non‐Hodgkin lymphomas. We wanted to assess the ability of flow cytometric evaluation of Ki67 index (Ki67I) in differentiating the grade of malignancy in canine lymphomas. Ki67I was determined on lymph node aspirates of 90 immunophenotyped lymphomas classified according to the updated Kiel classification: 80 high grade (HG, 62 B cell and 18 T cell) and 10 low grade (LG, 3 B cell and 7 T cell) lymphomas. HG lymphomas showed significantly higher Ki67I compared with LG lymphomas (P < 0.0001). A significant difference in HG lymphomas was detected between B‐ and T‐immunophenotypes. Receiver operating characteristic (ROC) curve highlighted a high accuracy of Ki67I in recognizing HG lymphomas [area under the curve (AUC) = 99.4] and a cut‐off value of 12.2% was established (sensitivity = 96.3% and specificity = 100%). Thus, we suggest the combination of Ki67I flow cytometric determination and immunophenotype as a reliable tool to classify canine lymphomas.     

猪繁殖—呼吸综合征病毒的形态学

利用电子显微技术，对从上海某发病猪场分离到3株猪繁殖－呼吸综合征病毒（PRRSV）和标准美洲株（ATCC－VR2332）进行了形态特征的比较。结果表明，这4株病毒形态特征无显著差异。负染显示该病毒以球形为主，具有囊膜，囊膜上有纤突，大小为60－85nm。超薄切片可见病毒粒子大量存在于细胞浆内，有囊膜的直径为60－80nm，没有囊膜的直径为40－50nm，在细胞的线粒体，高尔基体和双基核膜内可见病毒粒子。在病毒增殖的同时，Marc-145细胞的显微结构逐渐发生破损，显示病毒的释放是通过破坏细胞膜结构的完整性来实现的。     

Cell tropism of Staphylococcus aureus in bovine mammary gland cell cultures.

Staphylococcus aureus is one of the most important pathogens of the bovine mammary gland. The interaction of S. aureus with cells of the bovine mammary gland is considered to play an essential role in the pathogenesis. In this study, we identified a new target cell for S. aureus adhesion and invasion. For that purpose, cells which compose the alveoli of the mammary gland were cultured. In these cultures, two morphologically different cell types, elongated and cubic cells, were observed. Adhesion and invasion of S. aureus was studied using microscopical and microbiological methods. S. aureus adhered specifically and in large numbers (about 300 bacteria/cell) to the elongated cell type. No adhesion to the cubic cell type was observed. In addition, bacteria were also found intracellularly in the elongated cells, and enclosed in membrane vesicles. Adhesion and invasion were time dependent and reached maximum levels after 4 h. Invasion was strongly reduced by staurosporine and genistein. The newly identified target cell was further characterized.