Morfologia da laringe de cutia (Dasyprocta sp) / Morphology of the larynx of agouti (Dasyprocta sp)

A cutia (Dasyprocta sp.) é um roedor silvestre com distribuição mundial. Atualmente, além de importante papel ecológico que exerce, está sendo utilizada como modelo em experimento animal. Estudos sobre a morfologia destes animais são importantes porque podem ser uma alternativa para o estudo de diversos processos patológicos, além de contribuirem para a preservação da espécie. A laringe é um órgão localizado entre a faringe e a traqueia, no qual está envolvido nas funções de respiração, deglutição e fonação. O presente estudo propôs realizar uma descrição morfológica macroscópica e microscópica da laringe da cutia. Para tanto, foram utilizadas quinze cutias pertencentes ao Centro de Ciências Agrárias da Universidade Federal do Piauí e provenientes do Núcleo de Estudos e Preservação de Animais Silvestres com licença do IBAMA (Nº 02/08-618, CTF Nº 474064). Todos os animais foram identificados, promovida a sexagem e, posteriormente, a laringe acessada e dissecada sendo os fragmentos cartilagíneos encaminhados para rotina histológica e corados pelo método de hematoxilina-eosina. As lâminas obtidas foram visualizadas em microscopia óptica de luz e foto documentadas. A laringe da cutia apresenta cinco cartilagens, com ausência da cartilagem cuneiforme e presença da incisura caudal na cartilagem tireoide. O tecido epitelial da laringe varia de epitélio estratificado pavimentoso queratinizado à não queratinizado e ciliado com células caliciformes.

The agouti (Dasyprocta sp.) is a wild rodent with worldwide distribution. Besides its ecological role, agouti is used as a model in animal experimentation. Studies on the morphology of agouti are important because they can be an alternative for the study of various pathological processes and contribute to the preservation of the species. The larynx, located between the pharynx and trachea, is involved in the functions of breathing, swallowing and speech. This study aimed to perform a macroscopic and microscopic morphology of the larynx of agouti. To this end, we used fifteen agoutis belonging to the Centre of Agricultural Sciences, Federal University of Piauí, and from the Center for Study and Preservation of Wild Animals with license of IBAMA (No. 02/08-618, CTF No. 474064). All animals were identified according to their gender, the larynx was dissected and cartilaginous fragments were sent for routine histology and stained with hematoxylin-eosin. The slides obtained were viewed in light microscopy and photo documented. The larynx of agouti has five cartilages, without the cuneiform cartilage but presence of the thyroid cartilage notch. The epithelial tissue of the larynx varies from stratified squamous epithelium to keratinized and non-keratinized ciliated caliciforme cells.

Protective effect and granuloma down-modulation promoted by RP44 antigen a fructose 1,6 bisphosphate aldolase of Schistosoma mansoni.

A Schistosoma mansoni adult worm cDNA expression library was screened using rabbit IgG against PIII, an adult worm protein fraction, already known to possess protective and immunomodulating effects to a challenge infection in mice. A positive cDNA clone was selected and characterized. The cDNA screened encodes a protein (P44) with an ORF of 1089 bp and an amino acid sequence of 363 residues with a predictable molecular weight of 44 kDa. The P44 amino acid sequence exhibits 100% identity to the fructose 1,6 bisphosphate aldolase of S. mansoni, 66% to Homo sapiens and 66% to Mus musculus. The cDNA was cloned into a pGEX-4T-3 vector and expressed in Escherichia coli as a fusion protein (GST/P44). Mice vaccinated with recombinant P44 were able to develop high levels of IgG or IgG1 and displayed low levels of IgG2a isotype. Moreover, immunization of mice with this antigen induced a significant protection of 57% against a challenge infection and significant decrease in hepatic granuloma formation. Our results demonstrate that granuloma modulation can be targeted for pathology elimination through vaccination. This represents an advance in schistosome vaccinology and allows for the development of a therapeutic as well as a prophylactic vaccine.

Fibroblast growth factor 9: cloning and immunolocalisation during tooth development in Didelphis albiventris.

There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.