Cloning and molecular modeling of a thermostable carboxylesterase from the chicken uropygial glands.

Starting from total uropygial glands mRNAs, chicken uropygial carboxylesterase (cuCES) cDNA was synthesized by RT-PCR and cloned into the PGEM-T vector. Amino acid sequence of the cuCES is compared to that of human liver carboxylesterase 1 (hCES1). Given the high amino acid sequence homology between the two enzymes, a 3-D structure model of the chicken carboxylesterase was built using the structure of hCES1 as template. By following this model and utilizing molecular dynamics (MD) simulations, the resistance of the chicken carboxylesterase at high temperatures could be explained. The docking of substrate analogs into the cuCES active site was used to explain the fact that the chicken carboxylesterase cannot hydrolyze efficiently large substrate molecules.

Ki-67 labeling in canine perianal glands neoplasms: a novel approach for immunohistological diagnostic and prognostic.

BACKGROUND: The antibody Ki-67 is a reliable and easy tool to accurately assess the growth fraction of neoplasms in humans and animals, and it has been used to predict the clinical outcome. Therefore, the aim of the present study was to investigate the immunohistochemical expression pattern of Ki-67 in normal and neoplastic perianal glands of dogs to evaluate the possible use of this proliferation marker as an ancillary method of perianal tumor diagnosis. We studied 42 cases of perianal gland neoplasms including adenomas (n = 15), epitheliomas (n = 15), and carcinomas (n = 12). As controls, 13 tissue samples from normal perianal glands were used. A Ki-67 index was established by a computer-assisted image analysis and compared with manual counting. RESULTS: Out of the 42 cases of perianal gland neoplasms, 34 were from males and eight from females. Recurrence was reported in 14 cases, being higher (8/12) in carcinomas. Immunostaining for Ki-67 revealed that the carcinomas showed a higher proliferation rate (9.87%) compared to groups of epitheliomas (2.66%) and adenomas (0.36%). For adenomas and epitheliomas of the perianal glands the computer-assisted counting and the manual counting gave similar results; however, only the computer-assisted image analysis was efficient to predict the perianal gland carcinoma recurrence. CONCLUSION: Since there were significant differences in the number of Ki-67-positive nuclei, this marker proved to be effective in helping the classification of perianal gland neoplasms and to refine the diagnosis criteria, especially in those samples with high variation in morphology/area. Also, higher Ki-67 index is related to recurrence in cases of perianal gland carcinomas. Further, the computer-assisted image analysis proved to be a fast and reliable method to assess the Ki-67 index in perianal gland neoplasms.

Histochemical analyses of anti-microbial substances in canine perianal skin with special reference to glandular structures.

Circumanal glands are prominent features of the canine perianal skin, which are often located near to the sebaceous glands and apocrine glands. As the functional relevance of circumanal glands is yet unknown, we studied the localisation of sialic acids and anti-microbial substances (lysozyme, immunoglobulin A, lactoferrin, ß-defensin) in these glandular structures by lectin histochemistry and immunohistochemistry. The glands exhibited a number of sialic acids that were linked to α2-6Gal/GalNAc and α2-3Galß1-4GlcNAc. Additionally, lysozyme, lactoferrin and ß-defensin could be demonstrated in the three types of skin glands, whereas IgA was only detectable in the apocrine glands. The results of the study suggest the specific significance of the circumanal glands. Independent of a certain endocrine role, their products may mainly function as protective agents to preserve the integrity of the anal region, considering that sialic acids and anti-microbial substances are important in defence mechanisms.

Identification of volatiles from the secretions and excretions of African wild dogs (Lycaon pictus).

Gas chromatography/mass spectrometry was used to identify 103 organic compounds from urine, feces, anal glands, and preputial glands of free-ranging African wild dogs, Lycaon pictus. Aliphatic acids were the dominant class of compound in all materials. In addition to aliphatic acids, urine contained dimethyl sulfone, 1,3-propanediol, benzoic acid, 1-methyl-2,4-imidazolidinedione, and squalene as major components: feces contained indole and cholesterol; and both contained 2-piperidone, phenol, 4-methyl phenol, benzeneacetic acid, and benzenepropanoic acid and other compounds. Anal gland secretion was particularly rich in cholesterol and fatty acids, and preputial gland secretion rich in squalene. A large majority of the identified compounds have been reported from other mammals, including species sympatric with African wild dogs. Eleven of the African wild dog components have not been reported previously from mammals and have not been found in sympatric species; one component, 1-methylimidazole-5-carboxaldehyde has not been reported previously as a natural product. In the chemical profiles of their urine, feces, and anal gland secretion African wild dogs differ markedly from other canids.

Potential semiochemical molecules from birds: a practical and comprehensive compilation of the last 20 years studies.

During the past 2 decades, considerable progress has been made in the study of bird semiochemistry, and our goal was to review and evaluate this literature with particular emphasis on the volatile organic constituents. Indeed, since the importance of social chemosignaling in birds is becoming more and more apparent, the search for molecules involved in chemical communication is of critical interest. These molecules can be found in different sources that include uropygial gland secretions, feather-surface compounds, and molecules from feces and skin. Although many studies have examined the chemical substances secreted by birds, research on bird chemical communication is still at the start, so new strategies for collecting samples and development of new methods of analysis are urgently required. As a first step, we built a database that brings together potential semiochemicals, using a unique chemical nomenclature for comparing different bird species and also for referencing the different classes of substances that can be found in order to adapt future parameters of analysis. The most important patterns of the wax fraction of preen secretions are highlighted and organized in an ordered table. We also draw up a list of various combinations of sampling and analytical techniques, so that each method can be compared at a glance.

Protein expression of Mdm2 and p53 in hyperplastic and neoplastic lesions of the canine circumanal gland.

Hyperplastic and neoplastic lesions of the circumanal gland in dogs were examined immunohistochemically for nuclear expression of Mdm2 and p53 proteins. Mdm2 nuclear labelling was detected in 64.3% of hyperplastic lesions and 70.7% of adenomas, the immunolabelling being stronger in the latter. Mdm2 reactivity in reserve-like cells in adenomas showed wide variation, the immunoreactive cells ranging from 4 to 80%. No reactivity was shown in 81.9% of adenocarcinomas. In contrast to Mdm2 reactivity, each of 14 hyperplastic lesions and 11 adenocarcinomas, and 60 of 65 adenomas (92.3%) failed to show nuclear p53 reactivity. These results suggest that increased expression of Mdm2 is an early event in circumanal gland tumorigenesis, and may be present in the absence of nuclear p53 protein accumulation.

Anogenital gland secretions of Lemur catta and Propithecus verreauxi coquereli: a preliminary chemical examination.

Although prosimians are greatly olfaction-oriented, little is known about the specifics of how they use scent to communicate. In this preliminary study we attempted to delineate intra- and interspecific differences among the anogenital gland secretions of two lemur species (Lemur catta and Propithecus verreauxi coquereli) using gas chromatography-mass spectrometry (GC-MS). The results indicate that the two species are discernible through scent. Furthermore, we were able to identify reproductive status using this technique. The anogenital secretions of the different sexes in L. catta, though perhaps not P. v. coquereli, are chemically distinguishable. Given this information, it appears that at least some lemur species can use scent marks to determine species, sex, and reproductive status.

[Detection of hepatoid glands and distinctive features of hepatoid acinus]. / Obnaruzhenie gepatoidnykh zhelez i otlichitel'nye cherty gepatoidnogo atsinusa.

In the 1920s-1930s, skin glands of a new type, hepatoid glands, were described in 13 mammal species (Rodentia, Canidae, and Bovidae). The hepatoid glands resemble sebaceous glands in their morphology, bur radically differ from them in specific structure of the acinus and another type of secretion. Later, these data either could not be confirmed or were considered insignificant and the hepatoid glands were described as modified sebaceous glands, glands with uncertain function, or modifications of epidermis. Based on the studies of various hepatoid glands in 22 species of Carniviora and Artiodactyla, the authors described in detail the characteristic features of the hepatoid acinus, which allow a precise discrimination of hepatoid and sebaceous glands. Extracellular secretory canaliculi have been described in the hepatoid glands, as well as the richness of hepatoid glands in protein, distribution of hydrophobic lipids in certain hepatoid glands, and formation of excretory ducts and cysts. The hepatoid glands are a source of great amounts of protein secreted in the merocrine way; the secretory substance of some of these glands has a strong odor.

Glycoconjugate expression in normal hepatoid glands and hepatoid gland adenomas and carcinomas in dogs.

Although neoplastic changes in canine hepatoid perianal glands (HPG) are quite common, the biological behaviour is sometimes difficult to assess on the basis of the histopathological examination. In an attempt to detect differences in the glycoconjugate expression between normal and neoplastic HPG, and to verify their relation to the degree of neoplastic progression, normal and neoplastic HPG were studied in 13 dogs, using 11 biotinylated lectins. In HPG adenomas the majority of the cells did not stain or stained weakly after incubation with pokeweed mitogen, LCA and UEA-I. In HPG carcinoma the basal cells lost the specific binding for WGA while heterogeneous distribution of conconavalin-A staining was observed.