Keratin staining of canine epithelial tissues by a polyclonal antiserum

Expression of cytokeratins and vimentin in normal and neoplastic tissue from the bovine female reproductive tract

The distribution of cytokeratins (CKs) and vimentin in the normal genital tract of calves and cows at different stages of the oestrous cycle and in epithelial tumours of the tract was studied immunohistochemically. Few differences in CK and vimentin immunolabelling were detected in relation to age or stage of the oestrous cycle. Coexpression of CKs in simple epithelia and in basal cells of stratified epithelia was detected in the oviduct and endocervix; this coexpression was different from that previously described in women. The demonstration of CKs but not vimentin in the neoplastic cells of a serous superficial ovarian papilloma suggested an origin from the ovarian surface epithelium, while the coexpression of CKs and vimentin in serous papillary and mucinous cystadenomas pointed to a possible origin from the rete ovarii. Studies on three uterine adenocarcinomas and the ovarian metastases from two of these showed an endometrial-CK phenotype. The intermediate filament profile of normal endometrium, conserved in uterine adenocarcinomas and their ovarian metastases, may be useful in discriminating between ovarian metastases from endometrial carcinomas and those originating from primary carcinomas in other organs.

Intermediate filament expression and lectin histochemical features of canine transmissible venereal tumour

Immunocharacterization of intermediate filament proteins and lectin-binding studies were carried out in canine transmissible venereal tumour (TVT), a unique neoplasia sharing some epidemiological features with Kaposi's sarcoma in humans. Neoplastic cells express vimentin, but neither cytokeratin nor desmin. Regarding lectins, TVT cells express receptors for Triticum vulgaris (WGA), Concanavalia ensiformis (Con A) and Ricinus communis I (RCA-I). They appear to be negative for Ulex europaeus-I (UEA-I), Arachis hypogaea (PNA), Glycine maximus (SBA) and Dolichos biflorus (DBA).

Distribution of the intermediate filament proteins vimentin, keratin, and desmin in the bovine ovary

The distribution of the intermediate filament (IF) proteins desmin, keratin, and vimentin was studied immunohistochemically in bovine ovaries. Special attention was paid to granulosa cells to examine possible marked changes of IF distribution in relation to folliculogenesis during ovarian development. Therefore, ovaries were used from fetuses from 3 months of gestation onward, calves, heifers, and cows. In all ovaries, desmin immunoreactivity was restricted to smooth muscle cells in blood vessel walls. Keratin appeared a characteristic of the ovarian surface epithelium. Co-localization of keratin and vimentin was observed in the epithelium of rete ovarii tubules in fetuses and calves, and in cortical cord epithelium and pregranulosa cells of primordial follicles in fetuses at 3-7 months of gestation. Vimentin was demonstrated in endothelium and in fibroblasts. In addition, vimentin immunoreactivity was present in granulosa cells of primary, secondary, and antral follicles. In antral follicles, these granulosa cells mainly had an elongated appearance and either contained an oblong or a round nucleus. Those with an oblong nucleus were characteristic for atretic antral follicles. In nonatretic follicles, numerous vimentin immunoreactive, elongated granulosa cells with a round nucleus were observed, especially in the peripheral granulosa layer and in small ( < 3 mm in diameter) antral follicles. Additionally, in antral follicles, protrusions of vimentin-positive corona radiata cells were observed, that penetrated the zona pellucida to contact the oocyte. The data show that the distribution of vimentin containing IFs is associated with various aspects of granulosa cell activity, as mitosis, atresia, and intercellular transport.

Immunohistochemical distribution of keratin proteins in feline tissues

The immunohistochemical distribution pattern of some keratin intermediate filament proteins has been analysed in a wide range of formalin fixed, paraffin embedded feline tissues using one polyclonal and two monoclonal antibodies raised against human keratins by means of the avidin-biotin-peroxidase complex technique. Only the epithelial and mesothelial cells were stained by the three antibodies, but differences in their corresponding staining pattern were noticed. The staining reaction of the polyclonal antibody raised against human skin keratin was found in both stratified and complex epithelia, while that of the monoclonal antibody which recognizes human keratins 8 + 18 + 19 of the Moll catalogue (NCL-5D3) was restricted to some simple epithelia. The staining reaction of the monoclonal antibody which reacts with human keratins 5 + 8 of the Moll catalogue (RCK-102) covered the widest spectrum of feline epithelial tissues analysed, including stratified, complex and simple epithelia. These staining patterns of feline tissues are basically similar with respect to those of corresponding tissues in other mammalian species, although some differences were also noticed and some obvious epithelial tissues were not stained. This study confirms the broad interspecies cross-reactivity of keratin proteins antibodies and demonstrates their capability to differentiate between various types of feline epithelia and some epithelial compartments.

Immunohistochemical distribution of vimentin, desmin, glial fibrillary acidic protein and neurofilament proteins in feline tissues

The immunohistochemical distribution pattern of vimentin, desmin, glial fibrillary acidic protein and neurofilaments intermediate filament proteins has been analyzed in a wide range of formalin fixed, paraffin embedded tissues using polyclonal and monoclonal antibodies raised against non-feline antigens. The vimentin antibody reacted with mesenchymal cells, the desmin antibody with striated and smooth muscle fibres, the glial fibrillary acidic protein antibody with glial cells in the central and peripheral nervous system, and the neurofilament proteins antibody with neuronal cell bodies and processes. In addition, some epithelial cells were vimentin positive, perisinusoidal liver cells were desmin positive, and basal/myoepithelial cells of the mammary gland, and luteinic cells were glial fibrillary acidic protein positive. These staining patterns of feline tissues are basically similar with respect to that of corresponding tissues in other mammalian species for each of the four intermediate filament proteins studied, but some differences have been also noticed. This study confirms the broad interspecies cross-reactivity of intermediate filament proteins antisera and demonstrates their capability to differentiate particular types of feline cells and tissues.

Immunohistochemistry with keratin, vimentin, desmin, and alpha-smooth muscle actin monoclonal antibodies in canine mammary gland: normal mammary tissue

Normal canine mammary gland tissue was studied immunohistochemically with monoclonal antibodies (MoAbs) directed against various human keratin types, vimentin, desmin, and alpha-smooth muscle actin. Both ductal and alveolar luminal cells were immunoreactive with MoAbs recognizing respectively human keratins no. 7, 8, 18 and 19. In addition, some ductal luminal cells were labelled with a keratin 4 and a keratin 10 MoAb. Basal/myoepithelial cells were immunoreactive only with MoAbs directed against keratin 14, keratins 14 and 17, and alpha-smooth muscle actin. The vimentin MoAb merely labelled solitary loose intraluminal cells representing macro-phages or sloughed epithelial cells. These findings correspond largely to observations made in human breast tissue.

The expression of keratins, vimentin, neurofilament proteins, smooth muscle actin, neuron-specific enolase, and synaptophysin in tumors of the specific glands in the canine anal region

Eight canine tumors originating from specific glandular structures in the anal region, as well as metastatic tumor tissue of two of these cases (case Nos. 7, 8), were immunohistochemically analyzed using various monoclonal antibodies (MoAbs) directed against human keratin types, vimentin, neurofilament proteins, and alpha-smooth muscle actin. These tumors also were stained for the broad-spectrum neuroendocrine markers neuron-specific enolase (NSE) and synaptophysin. In histologically normal canine anal structures, alpha-smooth muscle actin and NSE antibodies stained basally localized (probably myoepithelial) cells in the anal glands and the anal sac glands. NSE staining also was present in a limited number of luminal cells in both anal glands and anal sac glands. Synaptophysin labeling was not observed in any of these glandular structures. Histologically, the tumors were differentiated into well- and moderately differentiated perianal gland tumors (n = 5) and carcinomas without perianal gland differentiation (n = 3), corresponding to the so-called apocrine carcinomas of the anal region. Immunohistochemically, the perianal gland tumors could be differentiated from the carcinomas by marked differences in staining pattern with the various keratin MoAbs, particularly MoAbs directed against human keratin types 7 and 18. The keratin-staining characteristics of the carcinomas suggest a glandular luminal cell origin. Metastases of the carcinomas showed loss of some keratin-staining characteristics as compared with the primary tumor. Staining for NSE was only observed in solitary cells and small cell clusters in the carcinomas and their metastases, whereas the alpha-smooth muscle actin antibody did not react with the carcinoma cells. None of the tumors stained for neurofilament proteins or synaptophysin. An unequivocal neuroendocrine nature of the carcinomas could not be substantiated by our immunohistochemical study, although the presence of a population of neuroendocrine cells within these neoplasms seems likely. Because the immunohistochemical features of the carcinomas with respect to various keratin MoAbs and NSE are similar to those of the anal glands and the anal sac glands, both these glands might be considered as site of origin of these carcinomas.

Rhabdomyosarcomas in young pigs in a swine breeding farm: a morphologic and immunohistochemical study

Within a 6-month-period, solitary or multiple tumors were observed in 25 young pigs in their first weeks of life in a swine breeding farm. The herd comprised approximately 100 animals, and affected pigs were observed in several litters. The number of affected littermates varied from one to three. Five animals, all from different litters and with a total of 11 tumors, were studied. Histologically the tumors were classified as undifferentiated sarcomas. Electron microscopic examination of the tumors (n = 3) revealed myogenic differentiation, characterized by the presence of numerous cytoplasmic filaments with longitudinal densities and cytoplasmic dense bodies. Immunohistochemically, all 11 tumors were labeled by vimentin and desmin antibodies. Two tumors from which frozen material was available were additionally labeled by a titin antibody but did not show immunoreactivity with antibodies directed against myosin and alpha-sarcomeric actin. The tumors were finally diagnosed as undifferentiated rhabdomyosarcomas. The high incidence of these tumors within a short period of time in multiple young animals in different litters indicates a common causative event. The clinical history suggests a genetic cause.

Immunohistochemistry with keratin monoclonal antibodies in canine tissues: urogenital tract, respiratory tract, (neuro-)endocrine tissues, choroid plexus and spinal cord

Twelve oligo- or monospecific monoclonal antibodies (MoAbs) directed against human keratin types were used in an immunohistochemical study of the canine male and female urogenital tract, the respiratory tract, the adrenal gland, the (para-)thyroid gland, the choroid plexus and the spinal cord. The keratin MoAbs showed differences in staining patterns in the various epithelial tissues and the diverse epithelial cells. The kidney was characterized by a complex keratin staining pattern and the canine urothelium showed regional differences in keratin staining. Also in the female genital tract different keratin staining patterns were observed. Testicular and adrenal gland cells did not react with any of the keratin MoAbs. The keratin staining patterns in the various canine tissues showed, in addition to similarities, also distinct differences when compared to the staining patterns in corresponding tissues of other species, e.g. of man. These staining dissimilarities indicate that the reactivity patterns of the keratin MoAbs with restricted keratin immunoreactivity can not be always extrapolated from one species to another. Nevertheless, MoAbs directed against human keratin proteins can apparently be used to differentiate between various types of canine epithelia or epithelial compartments.

Immunohistochemistry with keratin and smooth muscle actin monoclonal antibodies in canine digestive tract and extramural glands

The canine digestive system and its extramural glands (parotid gland, liver, pancreas) were immunohistochemically studied using a panel of twelve monoclonal antibodies (MoAbs) specific for human keratin proteins and for alpha-smooth muscle actin. Various epithelial tissues and cells were characterized by different keratin staining patterns. So, the epithelial lining of the upper alimentary tract was characterized by staining with the MoAb 6B10, specific for keratin-type (K) 4, and the absence of staining with the MoAbs directed against K 8 and 18 (CAM 5.2 and RGE 53, DE-K18 respectively), whereas the lower alimentary tract epithelium was not labeled by 6B10, but stained by the latter MoAbs. In the salivary glands the luminal and basal cells of the adenomeres as well as the different ductal structures could be immunohistochemically differentiated. The duct epithelium in liver and pancreas showed next to keratin staining characteristics in common with hepatocytes and exocrine pancreatic cells, additional staining by several keratin MoAbs. The keratin staining patterns in the canine tissues showed, in addition to similarities also distinct discrepancies when compared to the staining patterns in corresponding human tissues. Myoepithelial cells in salivary and oesophageal glands could be differentiated from other basally located epithelial cells by their exclusive immunoreactivity for alpha-smooth muscle actin. Canine pancreatic endocrine cells were not labeled by any of the keratin MoAbs. It is concluded that immunohistochemistry with polypeptide specific MoAbs specific for human keratin-types can be used to differentiate between different types of canine epithelial tissues and epithelial cells in the digestive tract. As a result such reagents may find their application in developmental biology and pathology of this species.

Caprine peripheral neuroblastomas: structural and ultrastructural features, intermediate filaments profile and neuro-endocrine characterization

In this report the morphological and immunohistochemical features with respect to intermediate filament proteins and the neuroendocrine nature of bilateral neuroblastomas possibly originating from the adrenal medulla in a goat kid are presented. Histologically, the tumours were composed of small, round, blue cells organized in highly cellular nests and sheets separated by fibrovascular septa. Isolated cells mimicking the morphological features of neurones were observed in both tumours. Ultrastructurally, dense-core neurosecretory granules, about 100 nm in diameter, and irregularly organized neurotubular networks were seen. The small tumour cells were only labelled by vimentin, while the neurone-like cells were labelled by both neurone-specific enolase and synaptophysin. The lack of staining of the tumour cells by the neurofilament proteins antiserum, which was also observed in a human neuroblastoma (used as positive control) has been previously reported and is probably the result of the tissue processing and/or the poor differentiation stage of the tumours. The vimentin labelling of tumour cells could be explained by the poor differentiation stage of the tumours, since vimentin is the only intermediate filament protein in presumptive neuroblasts, being replaced by neurofilament proteins in later stages of neurogenesis.

An immunohistochemical study of canine tissues with vimentin, desmin, glial fibrillary acidic protein, and neurofilament antisera

In a wide range of canine tissues the immunoreactivity with commercially available antisera against intermediate filament antigens viz. vimentin, desmin, glial fibrillary acidic protein (GFAP) and neurofilament proteins, was studied. In addition, the results of formalin and Carnoy fixation were compared. Carnoy fixation appeared to result in optimal reactivity for all antisera. Epithelial cells did not react with any of the antisera, with exception of ovarian surface epithelium, which showed staining with the vimentin and desmin antisera. The vimentin antiserum induced staining of several cell types viz. fibroblasts, endothelial cells, chondrocytes, Schwann cells, ependymal cells, astrocytes, Leydig cells, synovial cells, podocytes and some parietal cells of Bowman's capsule. Sertoli cells showed a faint staining reaction. Muscle cells in various tissues reacted with the desmin antiserum. In the kidney a varying number of parietal cells appeared to react as did a restricted number of epithelial cells of proximal tubules and loops of Henle. GFAP reactivity was confined to glial cells, predominantly fibrous astrocytes, Schwann cells and axons. Additionally, some neuronal cell bodies in peripheral ganglia showed staining of varying intensity. Neurofilament staining was restricted to axons and some neurons. The immunoreactivity of canine tissues with these antisera is compared to findings in other species. The results confirm a broad interspecies cross-reactivity of these antisera. They can be used in studying the nature of canine tissues.