Mecanismos de Desarrollo de la Cúpula en los Conductos Semicirculares de las Aves: I. Secreción Celular

A study of the crista ampullaris of the vestibular apparatus was carried out in chicken embryos. The study group included embryos between stages 24 and 39 of Hamburger-Hamilton. This study elucidates the relationship of the cupula with respect to the epithelium of the crista ampullaris. With electron microscopic examination, the rough endoplasmic reticulum of the crista epithelial sustentacular cells at developmental stage of 31 H-H, demonstrated dilatations containing secretory material. Vesicles, with adhering ribosomes appear to be formed from these dilatations. At later stages of development, the vesicular material took on the characteristics of the fibrillary material composing the cupula. In some cells, secretory vesicles are seen near the apical border of these cells, where they apparently secrete vesicular contents into the endolymphatic space, contributing to the formation of the cupula.     

Air‐liquid interface cell culture: From airway epithelium to the female reproductive tract

The air‐liquid interface (ALI) approach is primarily used to mimic respiratory tract epithelia in vitro. It is also known to support excellent differentiation of 3D multilayered skin models. To establish an ALI culture, epithelial cells are seeded into compartmentalized culture systems on porous filter supports or gel substrata. After an initial propagation period, the culture medium is removed from the apical side of the epithelium, exposing the cells to the surrounding air. Therefore, nutritive supply to the cells is warranted only by the basolateral cell pole. Under these conditions, the epithelial cells differentiate and regain full baso‐apical polarity. Some types of epithelia even generate in vivo‐like apical fluid or mucus. Interestingly, the ALI culture approach has also been shown to support morphological and functional differentiation of epithelial cells that are not normally exposed to ambient air in vivo. This review aims at giving a brief overview on the characteristics of ALI cultures in general and ALI models of female reproductive tract epithelia in particular. We discuss the applicability of ALI models for the investigation of the early embryonic microenvironment and for its implications in assisted reproductive technologies.     

Involución de Germenes Dentarios en la Oveja (Ovis aries)

In this study we examined some histologic and histochemical characteristics of the embryonic sheep dental epithelium in early odontogenesis. During the first trimester of development, a short-lived dental lamina was observed. Apparently in the sheep, the interactions between epithelial and ectomesenchymal cells required for tooth normal morphogenesis are altered.     

Glycoproteins in the epithelium of lips and associated structures of a hill stream fish Garra lamta (Cyprinidae, Cypriniformes): a histochemical investigation

A series of histochemical procedures were employed to localize and characterize glycoprotein (GP) classes elaborated in the epithelia of the upper and lower lips and associated structures, namely the rostral cap, the adhesive pad, the horny upper and lower jaw sheaths and the folds of skin between them, of a hill stream fish Garra lamta. The epithelia of the lips, the folds of skin and the major portions of the rostral cap and the adhesive pad are mucogenic. The epithelia of the horny jaw sheaths and parts of the rostral cap and the adhesive pad are keratinized. Based on the histochemical characterization of GPs, the cells involved in the secretions in the epithelia at the mucogenic regions of the rostral cap and the adhesive pad comprise the epithelial cells, the type A mucous cells and the club cells. In the lips and the folds of skin, in contrast, the club cells are absent and most mucous cells belong to the type B category. Type A mucous cells are few. GPs elaborated by cellular components of the mucogenic epithelia include GPs with oxidizable vicinal diols, GPs with O-sulphate esters, GPs with sialic acid residues without O-acyl substitution or with O-acyl substitution at C7, C8 or C9 and GPs with O-acyl sugars. The different types of cells show significant differences in the classes as well as in the concentrations of the GPs elaborated by them. GPs have also been identified in the subcorneal space between the unculi and the epithelial cells in the replacement layer in the epithelia at the keratinized regions. Elaboration of more than one type of GPs suggests a basis for functional discrimination in their role in the mucous secretions at the surface as an adaptation to the feeding ecology and the environment inhabited by the fish.     

Histology,histochemistry and ultrastructure of the nasopharyngeal tonsil of the buffalo (Bubalus bubalis)

The light microscopic appearance and ultrastructure of the nasopharyngeal tonsil (tonsilla pharyngea), collected from 12 adult buffaloes of local mixed breed, were explored for the distribution of different types of epithelia, lymphoid tissue and high endothelial venules. The tonsillar mucosa was lined by pseudostratified columnar ciliated epithelium having goblet cells. The respiratory epithelium associated with the underlying lymphoid tissue formed the lymphoepithelium. The epithelium was further modified into follicle‐associated epithelium (FAE) characterized by reduced epithelial height, presence of a few dome‐shaped cuboidal cells equivalent of the M‐cells and absence of goblet and ciliated cells. The lymphoid tissue was distributed in the form of isolated lymphoid cells, diffuse lymphoid tissue and lymphoid follicles, mainly distributed within the propria‐submucosa along with the sero‐mucous glandular tissue. The goblet cells of the respiratory epithelium and the acinar cells contained different mucopolysaccharides. Scanning electron microscopy of the surface mucosa demonstrated a dense mat of cilia, island‐like arrangement of microvillus cells, M‐cells and a few brush‐like cells. The transmission electron microscopy revealed the different cell organelles of the respiratory epithelium and the FAE. Lymphocyte migration via the high endothelial venules in the propria‐submucosa was also observed.     

Induction of inflammatory host immune responses by organisms belonging to the genera Chlamydia/Chlamydophila

Chlamydia/Chlamydophila are a family of intracellular gram-negative bacteria that infect their hosts primarily via mucosal epithelia. Chronic disease associated with bacterial persistence, inflammation and tissue damage are common sequelae of infection with these organisms. Human epithelial cell lines respond to infection by releasing pro-inflammatory cytokines and chemokines such as interleukin (IL)-6 and IL-8, and upregulating the expression of mRNA encoding Iκ-B, the endogenous inhibitor of NF-κB. However, Iκ-B is not upregulated in response to bacterial lipopolysaccharide (LPS). The failure of epithelial cells to respond to LPS is associated with the absence of surface expression of CD14. Identification of the components of Chlamydia/Chlamydophila that can induce pro-inflammatory mediators coupled with the mechanisms by which epithelial cells detect infection and respond accordingly will advance the development of preventative strategies.     

Two cases of hereditary quadriplegia and amblyopia in a litter of Irish setters

Two, one-month-old male Irish setters from the same litter showed incoordination, rotary nystagmus and motor and visual impairment. No abnormalities were found in either the blood, urine or cerebrospinal fluid. Radiographs of the head, chest and abdomen were normal. Histopathology revealed degeneration and necrosis of the granular layer and Purkinje cells of the cerebellar cortex. On electron microscopic examination, the granular cells showed dilated endoplasmic reticulum and vacuolated mitochondrial cristae. There was also serious destruction of Purkinje cells.     

Embryonic adaptations and nutrition in the viviparous teleost Clinus dorsalis (Perciformes: Clinidae)

Embryos of Clinus dorsalis absorb nutrients from the embiyotrophe, secreted by the follicular epithelium. Autoradiographic studies revealed that the principal areas of nutrient absorption are the embryonic gut and epidermis. A histological and electron microscopic study of embryonic structure revealed an extensively hypertrophied gut with numerous flngerlike villi projecting into the gut lumen. A brushborder of microvilli is, furthermore, characteristic of the columnar gut epithelium. Epidermal surface area is increased apically on individual epidermal cells, particularly on the ventral pericardial surface. Micro ridges further increase epidermal surface area. Epidermal surface area is reduced and a mucous layer is secreted prior to parturition.     

Induction of inflammatory host immune responses by organisms belonging to the genera Chlamydia/Chlamydophila

Chlamydia/Chlamydophila are a family of intracellular gram-negative bacteria that infect their hosts primarily via mucosal epithelia. Chronic disease associated with bacterial persistence, inflammation and tissue damage are common sequelae of infection with these organisms. Human epithelial cell lines respond to infection by releasing pro-inflammatory cytokines and chemokines such as interleukin (IL)-6 and IL-8, and upregulating the expression of mRNA encoding Iκ-Bα, the endogenous inhibitor of NF-κB. However, Iκ-Bα is not upregulated in response to bacterial lipopolysaccharide (LPS). The failure of epithelial cells to respond to LPS is associated with the absence of surface expression of CD14. Identification of the components of Chlamydia/Chlamydophila that can induce pro-inflammatory mediators coupled with the mechanisms by which epithelial cells detect infection and respond accordingly will advance the development of preventative strategies.     

Effect of human interferon on vesicular stomatitis virus released from bovine embryonic kidney cells

Human lymphoblastoid interferon (IFN) had an antiviral activity in bovine embryonic kidney cells that resulted in the release of vesicular stomatitis virus (VSV) particles with decreased infectivity. The inhibition was dose dependent and the cells were highly sensitive to human IFN. Examination of the proteins of VSV released from bovine cells after IFN treatment showed a reduction in the glycoprotein. Electron microscopic studies revealed a large number of VSV particles with characteristic spike-like surface projections released from nontreated cells. There was a reduction in the number of mature virions produced in IFN-treated cells and the virions lacked the characteristic surface projections.     

Histopathological findings of cleft palate in rat embryos induced by triamcinolone acetonide

Triamcinolone acetonide (TAC), a synthetic glucocorticoid, induces cleft palate resulting from poor development of palatal shelves in mice. However, TAC has no effect on medial edge epithelial cells (MEE cells) in secondary palatal shelves. In the present study, we examined the relationship between the pathogenesis of cleft palate and the effects on MEE cells and palatal mesenchymal cells in rat embryos/fetuses exposed to TAC. Pregnant Wistar Hannover rats were given TAC intramuscularly at 0.5 mg/kg at gestation days (Day) 12, 13, and 14, then embryos/fetuses were harvested on Days 14.5, 15, 16 and 20. The effects of TAC were as follows; an inhibition of palatal mesenchymal cell proliferation on Day 14.5, a decrease in the density of palatal mesenchymal cells and MEE cells, and expression of epidermal growth factor (EGF) receptors in MEE cells on Day 15, and stratified squamous differentiation of MEE cells with expression of cytokeratin and EGF receptors on Day 16. These findings indicated that TAC inhibited the proliferation of mesenchymal cells and affected the differentiation of MEE cells into stratified squamous epithelia in the palatal shelves of rat embryos. However, these stratified squamous MEE cells partially fused with each other. Thus, we suspected that a major contributing factor to the formation of TAC-induced cleft palate might not be the altered differentiation of MEE cells, but the inhibition of mesenchymal cell proliferation.     

Electron microscopic studies on conjunctiva associated lymphoid tissue (CALT) in Angora goats

The purpose of this study was to investigate the electron microscopic structure of conjunctiva associated lymphoid tissue (CALT) and to determine the uptake of macromolecules from follicle associated epithelium (FAE) of Angora goats. The sample tissues taken from lower and upper eyelids of ten 5-6 month-old healthy Angora goats were used in this study. The conjunctiva associated lymphoid tissue of Angora goats was formed by solitary or aggregate lymphoid follicle and follicle associated epithelium which cover these follicle. FAE was formed by flattened epithelial cells, lymphocytes, monocytes and polymorph nuclear leukocytes but no goblet cells. Ferritin particles were seen on the apical surface, in the invaginations, vesicles, vacuoles of flattened epithelial cells. It was concluded that these epithelial cells were specialized to uptake macromolecules.     

Parasitic forms of a myxosporean in the kidney of the arctic lamprey, Lampetra japonica: an ultrastructural study

We found frequent and unique parasitism by an unidentified myxosporean in the kidney of the arctic lamprey, Lampetra japonica, living in Japan. Trophozoites (pseudoplasmodia with or without sporoblasts) existed predominantly in the lumina of proximal urinary tubules, but were rarely found in any other regions of the kidney. Since no mature spores were produced in the trophozoites, exact identification of the species was impossible. Two parasitic forms were recognized in proximal urinary tubules: one adhering to the epithelial cells of renal tubules, and the other free-floating in the lumina of tubules. Ultrastructurally, the attaching trophozoites developed microvilli-like projections towards the apical surface of epithelial cells and vigorously interdigitated with microvilli of the brush border. In contrast, the whole surface of the floating trophozoite was smooth without any cell projections. The developed projections in the former type of trophozoite may contribute to their firm attachment to the epithelial cells and/or to absorption of nutrients via the epithelial cells. Against the myxosporean infection, the lamprey as the host exhibited a local immune reaction by disposition of numerous lymphocytes and macrophages into the epithelium of urinary tubules.     

Distribution of neutral amino acid transporter ASCT 1 in the non-neuronal tissues of mice

Distribution of ASCT1, a neutral amino acid transporter, in non-neuronal peripheral tissues of adult and developing mice was examined by immunohistochemistry and immunoelectron microscopy. Immunoreactivity for ASCT1 in the digestive system was localized in basal cells of stratified squamous epithelia from oral parietes to nonglandular region of the stomach, chief cells of the glandular stomach, acinar cells of the salivary gland and exocrine pancreas, and Paneth's cells of the small intestine, in all of which the basolateral membrane was selectively immuno-labeled. In the liver of adult mice, ASCT1 immunoreactivity was detected on the plasma membrane of hepatocytes surrounding central veins, and a temporal expansion of immunoreactive hepatocytes was observed in the embryonic and CCl4-treated adult livers. ASCT1 was also localized on the plasma membranes of proximal uriniferous tubule epithelial cells in the kidney of adult mice, and those of supporting cells in the medulla of adrenal gland. These results suggest that ASCT1 is expressed in various non-neuronal peripheral tissues in mice, and it contributes to the amino acid transport throughout non-neuronal tissues.     

鸡小肠上皮细胞的分离培养与鉴定

选择组织块法分离培养鸡小肠上皮细胞(intestinal epithelial cells,IEC),采用机械刮除法和相差消化－相差贴壁法纯化细胞,0.05%的Trypsin-EDTA对获得的IEC进行消化传代,免疫细胞化学法鉴定IEC。结果表明,组织块培养法可分离出活性较强的IEC,并获得纯化的上皮细胞;形态学和免疫细胞化学法检测显示获得的细胞表面抗原呈阳性,鉴定为IEC;纯化的IEC可在体外稳定传代。     

Immunological characterization of the equine airway epithelium and of a primary equine airway epithelial cell culture model

Our understanding of innate immunity within the equine respiratory tract is limited despite growing evidence for its key role in both the immediate defense and the shaping of downstream adaptive immune responses to respiratory disease. As the first interface to undergo pathogen invasion, the respiratory epithelium is a key player in these early events and our goal was to examine the innate immune characteristics of equine respiratory epithelia and compare them to an in vitro equine respiratory epithelial cell model cultured at the air-fluid interface (AFI). Respiratory epithelial tissues, isolated epithelial cells, and four-week old cultured differentiated airway epithelial cells collected from five locations of the equine respiratory tract were examined for the expression of toll-like receptors (TLRs) and host defense peptides (HDPs) using conventional polymerase chain reaction (PCR). Cultured, differentiated, respiratory epithelial cells and freshly isolated respiratory epithelial cells were also examined for the expression of TLR3, TLR9 and major histocompatibility complex (MHC) class I and class II using fluorescence-activated cell sorting (FACS) analysis. In addition, cytokine and chemokine profiles from respiratory epithelial tissues, freshly isolated respiratory epithelial cells, and cultured, differentiated, epithelial cells from the upper respiratory tract were examined using real-time PCR. We found that respiratory epithelial tissues and isolated epithelial cells expressed TLRs 1-4 and 6-10 as well as HDPs, MxA, 2'5' OAS, β-defensin-1, and lactoferrin. In contrast, epithelial cells cultured at the AFI expressed TLRs 1-4 and 6 and 7 as well as MxA, 2'5' OAS, β-defensin-1, but had lost expression of TLRs 8-10 and lactoferrin. In addition, MHC-I and MHC-II surface expression decreased in epithelial cells cultured at the AFI compared to isolated epithelial cells whereas TLR3 and TLR9 were expressed at similar levels. Lastly, we found that equine respiratory epithelial cells express an array of pro-inflammatory, antiviral and regulatory cytokines and that after four weeks of in vitro growth conditions, equine respiratory epithelial cells cultured at the AFI retained expression of GM-CSF, IL-10, IL-8, TGF-β, TNF-α, and IL-6. In summary, we describe the development of an in vitro equine respiratory epithelial cell culture model that is morphologically similar to the equine airway epithelium and retains several key immunological properties. In the future this model will be a used to study equine respiratory viral pathogenesis and cell-to-cell interactions.     

Crb1在小鼠生后不同发育阶段子宫组织中的表达

应用HE染色方法和免疫荧光组织化学技术对小鼠生后不同发育阶段子宫组织结构的发育以及极性调控蛋白Crb1的定位表达进行了研究,结果显示,随个体发育,子宫管腔及子宫腺腔不断扩大,子宫内膜上皮持续增厚、固有层内子宫腺逐渐发达;4周龄时子宫腔面出现纤毛,随发育进程越来越发达;在各发育阶段的小鼠子宫组织中均有Crb1的表达,随个体发育表达呈现先增强后减弱的趋势,在8周龄时达到最强;Crb1主要定位于子宫内膜上皮细胞和子宫腺上皮细胞的胞膜和胞质,提示Crb1可能与小鼠子宫内膜上皮细胞和腺上皮细胞的极性建立和维持有关。     

Epithelial cell kinetics in the inflammatory process of chicken trachea infected with infectious bronchitis virus

All stages of degeneration and regeneration in chicken tracheal epithelium were studied morphologically following an intratracheal inoculation of infectious bronchitis virus (IBV). Viral antigen was detected in the cytoplasm of tracheal epithelium from 1 to 7 days post-inoculation (d.p.i.) with a peak on 3 d.p.i. At 1 d.p.i., almost all epithelial cells were involved in the degeneration. At this time, labelling index of bromodeoxyuridine (BrdU) in the basal cells showed significantly high value compared with control. At 2 and 3 d.p.i., a great number of basal cells were recognized, but the BrdU labelling index tended to decrease. At 4 and 5 d.p.i., the BrdU labelling index of basal cells significantly decreased than 1 d.p.i., and a few number of regenerated immature ciliated epithelia appeared. At 6 to 11 d.p.i., the ciliated columnar epithelia increased rapidly in number, and returned to the normal appearance except for non-ciliated patch by 13 d.p.i. These results suggested that the tracheal epithelial cells infected with IBV degenerated within 24 hours and proliferating activity of basal cells functioned immediately, and 3 to 4 days later, these basal cells were differentiated to the ciliated epithelia.     

Pseudo-placentational Endometrial Cysts in a Bitch

Cystic alterations of the canine endometrium compromise reproduction and fertility of the bitch and may lead to life-threatening diseases, such as pyometra. Even without clinical evidence, reduction of the uterine lumen by cysts implicates disturbances during migration, nidation and development of the embryo. Several studies point to the high variability of morphology of uterine endometrial cysts but they lack detailed analyses of alterations. In the present study, immunohistochemistry was used to investigate the expression of steroid hormone receptors (oestrogen, progesterone), proliferation activity, inflammation and infection in the cystic affected tissue regions in contrast to the normal endometrium. Oestrogen receptor expression showed a high density of receptors throughout the surface epithelial cells, crypt epithelial cells, glandular epithelial cells and stromal cells of the normal endometrium as well as the cystic affected regions. Proliferation in the cysts was verified in the middle and basal cells of the crypts. Neither in the endometrium nor in the cysts inflammatory processes or evidence of infection could be detected. Furthermore, lectin histochemistry and electron microscopic methods showed that lectin binding patterns and cell morphology of internal epithelial lining and surface epithelium of the cysts can be used to characterize and distinguish different types of cystic alterations. Analogies between epithelial cells of the glandular chambers of the canine placenta and the cystic cellular morphology, steroid hormone receptor distribution as well as lectin binding patterns of the endometrial cysts, as observed in this study, suggest to introduce the term 'pseudo-placentational endometrial cysts'.