Infection with different Neospora caninum strains causes differences in the glycosylation pattern in the uteri and placentae of Neospora caninum-infected heifers.

Neospora caninum is an obligate intracellular parasite that causes abortion in ruminants. Different strains produce differences in the severity of disease outcomes. These differences may cause physiological or pathological changes in cells, modifying the intercellular interactions and intracellular transport pathways that could be evidenced by identifying the terminal sugars. This study aimed to characterize the oligosaccharide pattern in the bovine placenta and uterus after infection with tachyzoites of three different strains of N. caninum (Nc-1, Nc-6 Argentina and Nc Spain-7) during early gestation. Fourteen heifers were inoculated intravenously on day 70 of gestation with 2 × 108 N. caninum tachyzoites and samples of placentae and uteri were analysed by histology and lectin histochemistry. In the infected groups, severe placentitis was associated with changes in lectin binding in the vascular endothelium by Lens culinaris agglutinin (LCA), Pisum sativum agglutinin (PSA) and Ricinus communis I (RCA-I) lectins, in the epithelial cells of the endometrial glands by RCA-I, Dolichos biflorus agglutinin (DBA), succinylated wheat germ agglutinin, peanut agglutinin (PNA), concanavalin-A (CON-A), LCA, PSA and Phaseolus vulgaris erythroagglutinin (PHA-e), and in the trophoblast layer by PNA, CON-A, LCA, PSA, PHA-e, soybean agglutinin, RCA-I, DBA and Bandieraea simplicifolia agglutinin (BSA-I). The results suggest that N. caninum causes changes in the glycosylation pattern in the maternofetal interface tissues and might cause abortions in early gestation due to changes in the cellular structure of the placenta.

Altered E-cadherin/ß-catenin expression in feline cutaneous squamous cell carcinomas.

Cutaneous squamous cell carcinoma (CSCC) is the most common malignant skin tumour in cats and the nature of the molecular mechanisms involved is poorly defined. Included among the molecular mechanisms in human and canine CSCCs is altered expression of E-cadherin/ß-catenin. This study aimed to explore the immunohistochemical expression pattern of E-cadherin and ß-catenin in 43 samples of feline CSCC by using a tissue microarray to elucidate whether expression of these molecules is dysregulated. Membrane expression of E-cadherin and membrane and cytoplasmic expression of ß-catenin were significantly reduced in the CSCCs. Cytoplasmic expression of E-cadherin and nuclear expression of ß-catenin were also found in some CSCCs. These findings indicate that altered expression of E-cadherin and ß-catenin is a frequent event in feline CSCCs, suggesting that these molecules play an important role in acquisition of the malignant phenotype in feline patients with CSCC. The results also suggest the existence of a subpopulation of feline patients with CSCC in which the Wnt pathway may contribute to epidermal carcinogenesis.

Determination of ptaquiloside in ten species of Pteris in northwestern Argentina.

The toxic effect of ferns of the genus of Pteris in bovines is caused by ptaquiloside, the main carcinogenic toxin. In this study, ten species of Pteris fern in different phenologic stages and plant conditions were collected in northwest Argentina. The phytochemical analysis showed the presence of Pt in the recent collected samples (adults and young plants) but not in the herbarium specimens. The results show a great variation of Pt concentration that depends on the phenologic stage, plant condition, and collection site. Pt was measured in 6-4326 µg/g concentration, with a mean concentration of 644 µg/g. No Pt was detected in eight species of Pteris collected from herbarium samples; such results may be a false negative. It is important to notice that analysis of herbarium samples for Pt may not be a reliable method to determine its presence. It is important to further understand the potential toxicity caused by these ferns because of their effect on animals, public health, and the environment.

Ovarian changes and development of the branchial placenta occurring in Jenynsia lineata (Cyprinodontiformes, Anablepidae).

In viviparous teleosts, intraovarian gestation occurs intrafollicularly, as in poeciliids, or intraluminally, as in goodeids and anablepids. Furthermore, there are two different forms of embryonic nutrition: lecithotrophy and matrotrophy; depending on the species, these can be exclusive or coexist during gestation. In matrotrophic species, nutrients are transmitted from the mother to the embryo and are especially important in species with intraluminal gestation. Jenynsia lineata is a South American viviparous teleost with intraluminal gestation, characterized by eggs with scarce yolk, which is resorbed when embryos are 6 mm long, thus developing a branchial placenta. Using histological, histochemical, and immunohistochemical techniques, the present study describes the characteristics and changes of the ovarian mucosa in J. lineata during gestational and nongestational phases, and analyzes the embryonic pharyngeal epithelium in the branchial placenta. The ovaries of 30 adult female specimens were processed using histological techniques and stained with hematoxylin-eosin, Masson's trichrome, and Alcian Blue pH 2.5/periodic acid Schiff reagent. To detect cell proliferation, we used antiproliferating cell nuclear antigen antibody. In nonpregnant females, eosinophilic granular cells (EGCs) and lymphocytes were identified in the lamina propria of the tunica mucosa, and melanomacrophage centers (MMCs) and fibroblasts were identified adjacent to tissue debris in the ovarian folds'. In the cellular debris, an embryo in resorption was observed. In pregnant females, the ovarian mucosa has thin vascularization branches entering the opercular chamber of the embryos, in close contact with the forming gill processes, thereby establishing a branchial placenta. Active cell replacement was observed in these ovarian branches. The identification of fibroblasts, lymphocytes, EGCs, and MMCs adjacent to tissue debris could indicate that these cell types are involved in the embryonic resorption process. Considering the new data obtained in this study on the branchial placenta of J. lineata, we conclude that cell proliferation could be involved in the development of maternal-embryonic interaction.

Persistent activation of the mammalian target of rapamycin signalling pathway in cutaneous squamous cell carcinomas in cats.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) represents the most common malignant tumour of the feline skin. Emerging evidence suggests that the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signalling pathway may represent a potential target for pharmacological intervention in human and canine CSCC. HYPOTHESIS/OBJECTIVES: The present study aimed to explore the expression pattern and status of activation of relevant signalling proteins of the PI3K/Akt/mTOR signalling pathway in feline CSCC. METHODS AND MATERIALS: The expression of pEGFRTyr1068 , pAktSer473 , pS6Ser235/236 combined with Ki-67, and the tumour suppressor protein PTEN was evaluated by immunohistochemical analysis in 45 samples of feline CSCC, using a tissue microarray. RESULTS: The immunodetection using phosphospecific antibodies to detect the activated forms of signalling proteins showed that the PI3K/Akt/mTOR signalling pathway is frequently activated in feline CSCCs, and may be independent of the activation of EGFR. The results also showed that PTEN expression is not significantly altered in feline CSCCs. CONCLUSIONS AND CLINICAL IMPORTANCE: Our study shows that the persistent activation of the PI3K/Akt/mTOR signalling pathway represents a key event in feline CSCC, pointing to this signalling pathway being a potential therapeutic target in feline patients with CSCC.

The uropygial gland of the monk parakeet Myiopsitta monachus: Histology, morphogenesis, and evolution within Psittaciformes (Aves).

We describe the morphology, histology, and histochemical characteristics of the uropygial gland (UG) of the monk parakeet Myiopsitta monachus. The UG has a heart-shape external appearance and adenomers extensively branched with a convoluted path, covered by a stratified epithelium formed by different cellular strata and divided into three zones (based on the epithelial height and lumen width), a cylindrical papilla with an internal structure of delicate type and two excretory pores surrounded by a feather tuft. Histochemical and lectin-histochemical techniques performed showed positivity against PAS, AB pH 2.5, AB-PAS, and some lectines, likely related to the granivorous feeding habits. Also, we describe the morphogenesis of the UG of the monk parakeet, which appears at embryological stage 34 as a pair of ectodermal invaginations. Heterochronic events in the onset development of the UG when compared with other birds could be recognized. Finally, to examine the phylogenetic occurrence of the UG within the Psittaciformes and infer its evolutionary history, we mapped its presence/absence over a molecular phylogeny. The reconstruction of the characters states at ancestral nodes revealed that the presence of the UG was the plesiomorphic feature for Psittaciformes and its loss evolved independently more than once.

Lectin histochemical pattern on the normal and cystic ovaries of sows.

The lectin histochemical pattern (LHP) was characterized and compared in normal and cystic ovaries of sows. Six biotinylated lectins (PNA, SBA, WGA, RCA-1, DBA and UEA-1) were used on tissue sections. In the normal ovaries, the reaction to UEA-1 and SBA was mild to moderate in mesothelial and endothelial cells. RCA-1 staining was mild to moderate in theca interna of growing follicles, corpora luteum and mesothelium. In addition, this lectin presented strong reaction in endothelial cells, granulosa cells of atretic follicles, zona pellucida of growing follicles and plasma. DBA showed strong intensity in mesothelial and endothelial cells. There was mild to moderate reactivity to WGA in granulosa cells, corpus luteum and theca interna of follicles in development, and moderate in zona pellucida, in granulosa cells of atretic follicles and mesothelium. PNA staining was mild to moderate in oocytes and in the adventitia and media of medullary arteries. Changes in the LHP of the cystic ovaries were noted; however, there were no differences in these findings between the follicular and luteinized cysts. UEA-1 reactivity in the cystic ovaries was moderately reduced in the mesothelial and endothelial cells, whereas there was mild reduction in the DBA staining in the granulosa cells. Reaction to RCA-1 and WGA in the cysts also was decreased in theca interna, zona pellucida and granulosa cells of atretic follicles. Furthermore, endothelium and theca interna in the cystic ovaries presented mild reduction of marcation to SBA, whereas there was decreased reactivity to PNA in the oocytes and adventitia and media layers of the medullary arteries. The results of the current study show that cysts modify the LHP in swine ovaries. These changes of glycoconjugates in many ovarian structures could modify diverse process and may be one of the reasons for decreased fertility in sows.

Dysregulated expression of the key effectors of the mammalian target of rapamycin signalling pathway in cutaneous papillomas of dogs.

Cutaneous papillomas (CP) are one of the most common skin neoplasms in dogs. Different murine models have shown that persistent activation of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway has a central role in the development and progression of CP. The purpose of this study were to evaluate the immunohistochemical expression pattern of two key molecules involved in the PI3K/Akt/mTOR signalling pathway, pAktSer473 , and pS6Ser235/236 , on 36 canine specimens of CP using a tissue microarray. The results show that the PI3K/Akt/mTOR signalling pathway is persistently activated in CP of dogs, pointing to this pathway as a potential therapeutic target.

Disrupting effect of androgens in postnatal female domestic cats.

To test the hypothesis that in domestic cats, postnatal androgens induce sterility, the aims of this study were to describe the reproductive effects and the clinical safety of a postnatal administration of a long term release androgen in this species. Thirteen newborn littermate female kittens were randomly assigned to one of the following treatment groups within the first 24h of birth: testosterone enanthate 12.5mg sc (TE; n=8) or Placebo (PL; n=5). The animals were subsequently assessed for fecal sexual hormones until puberty was attained and subsequently when matings occurred. After 21 days, ovulation and gestation were diagnosed. All queens were subsequently ovario-hysterectomized. Fecal testosterone concentrations differed between the treatment groups throughout the study period (P<0.05) being greater during the first 2 postnatal weeks in those of the TE group (P<0.01). Fecal estradiol was not affected by treatment (P>0.1). While all the females were receptive during the pubertal estrus (P>0.1), two TE (2/8) compared with all (5/5) females of the PL group had ovulations (P<0.05). Only one (1/2) compared with three (3/5) of the queens of the TE and PL groups, respectively became pregnant. All kittens of the TE group had transient clitoral enlargement. Anovulatory TE-treated cats had no corpus luteum, and a significant diminution of the endometrial glands as well as of the height of the uterine epithelium. It is concluded that, in domestic cats, a single postnatal supra-physiological dose of testosterone caused a large proportion of queens to be anovulatory and there were also histological endometrial abnormalities that also occurred with this treatment that were accompanied by mild and transient side effects.

Histochemical differences along the intestine of Corydoras paleatus (Siluriformes: Callichthyidae) / Diferencias histoquímicas a lo largo del intestino de Corydoras paleatus (Siluriformes: Callichthyidae)

AbstractThe Neotropical catfish Corydoras paleatus is a facultative air-breather and the caudal half of the intestine is involved in gas exchange. In South America, air-breathing fishes are found in tropical or sub-tropical freshwaters where the probability of hypoxia is high. The aim of this study was to characterize by traditional histochemical and lectinhistochemical methods the pattern of carbohydrate in the intestinal mucosa. Intestine samples were taken from 25 healthy adult specimens collected in Buenos Aires (Argentina). Samples were fixed by immersion in 10 % buffered formalin and routinely processed and embedded in paraffin wax. Subsequently, these sections were incubated in the biotinylated lectins battery. Labeled Streptavidin-Biotin (LSAB) system was used for detection, diaminobenzidine as chromogen and haematoxylin as a contrast. To locate and distinguish glycoconjugates (GCs) of the globet cells, we used the following histochemical methods: PAS; PAS*S; KOH/ PA*S; PA/Bh/KOH/PAS; KOH/PA*/Bh/PAS; Alcian Blue and Toluidine Blue at different pHs. Microscopically, the general structure of vertebrate intestine was observed and showed all the cell types characteristic of the intestinal epithelium. The cranial sector of catfish intestine is a site of digestion and absorption and its structure is similar to other fish groups. In contrast, enterocytes of the caudal portion are low cuboidal cells; and between these, globet cells and capillaries are observed, these latter may reach the mucosal lumen. Underlying the epithelium, observed a well-developed lamina propria-submucosa made of connective tissue; this layer was highly vascularized and did not exhibit glands. According to histochemistry, the diverse GCs elaborated and secreted in the intestine are associated with specific functions in relation to their physiological significance, with special reference to their role in lubrication, buffering effect and prevention of proteolytic damage to the epithelium together with other biological processes, such as osmoregulation and ion exchange. The lectinhistochemical analysis of the intestinal mucosa reveals the presence of terminal residues of glucose, mannose and galactose. In conclusion, this study has shown that GCs synthesized in the intestine of C. paleatus exhibit a high level of histochemical complexity and that the lectin binding pattern of the intestinal mucosa is characteristic of each species and the variations are related with the multiple functions performed by the mucus in the digestive tract. The information generated here may be a relevant biological tool for comparing and analyzing the possible glycosidic changes in the intestinal mucus under different conditions, such as changes in diet or different pathological stages. Rev. Biol. Trop. 64 (1): 327-340. Epub 2016 March 01.

ResumenEl pez neotropical Corydoras paleatus, de respiración aérea de tipo facultativa, utiliza el sector caudal del intestino para el intercambio gaseoso. En América del Sur, los peces con respiración aérea se encuentran en las aguas dulceacuícolas tropicales y subtropicales, donde la probabilidad de hipoxia es alta. El objetivo de este trabajo fue caracterizar mediante técnicas histoquímicas tradicionales y de lectinhistoquímica el patrón de carbohidratos de la mucosa intestinal. Para ello se utilizaron muestras de intestino de 25 ejemplares sanos adultos recolectados en la provincia de Buenos Aires (Argentina). Las muestras fueron fijadas en formol amortiguado al 10 % y se procesaron para su inclusión en parafina. Posteriormente, los cortes fueron incubados con una batería de lectinas biotiniladas. Se utilizó el sistema de marcado con estreptavidina-biotina (LSAB) para su detección, diaminobencidina como cromógeno y hematoxilina como colorante de contraste. Para localizar y diferenciar los glicoconjugados (GCs) de las células caliciformes, se utilizaron las siguientes técnicas histoquímicas: PAS, PAS*S, PAPS, KOH/PA*S, PA/Bh/KOH/PAS, KOH/PA*/Bh/PAS, Azul Alcian y Azul de Toluidina a diferentes pHs. Microscópicamente, se observa la estructura general del intestino de los vertebrados y el epitelio intestinal presenta todos los tipos celulares característicos de esta región. El sector craneal del intestino de este teleósteo, es el sitio de digestión y absorción, y posee una estructura similar a la de otros grupos de peces. En cambio, los enterocitos de la porción caudal, son células cúbicas bajas, entre ellos se observan células caliciformes y capilares sanguíneas que llegan hasta el lumen de la mucosa. Por fuera del epitelio, se observa una lámina propia-submucosa muy desarrollada compuesta por tejido conectivo, altamente vascularizada que no presenta glándulas. De acuerdo con las técnicas histoquímicas, los diversos GCs elaborados y secretados por la mucosa intestinal se encuentran asociados con funciones específicas de importancia fisiológica, como su rol en la lubricación, su efecto amortiguador y la prevención de daños proteolíticos del epitelio junto con otros procesos biológicos, tales como la osmorregulación y el intercambio iónico. El análisis lectinhistoquímico de la mucosa intestinal revela la presencia de residuos terminales de glucosa, manosa y galactosa. En conclusión, en este estudio se demuestra que los GCs sintetizados en el intestino de C. paleatus muestran un alto nivel de complejidad histoquímica y que el patrón de unión de lectina de la mucosa intestinal es característico para cada especie y las variaciones se hallan relacionadas con las múltiples funciones realizadas por el mucus en el tracto digestivo. La información brindada en este trabajo es una herramienta de relevancia biológica para comparar y analizar los posibles cambios glicosídicos del mucus intestinal bajo diferentes condiciones como los cambios en la dieta o diferentes estados patológicos.

Immunohistochemical and ultrastructural evidence of functional organization along the Corydoras paleatus intestine.

The Neotropical catfish, Corydoras paleatus (Callichthyidae) is a facultative air-breathing teleost that makes use of the caudal portion of the intestine as an accessory air-breathing organ. This portion is highly modified, being well vascularized with capillaries between epithelial cells, which makes it well suited for gas exchange. Instead, the cranial portion is a digestion and absorption site, as it has a typical intestinal epithelium with columnar cells arranged in a single row, villi and less vascularized tunica mucosa. Therefore, the intestine was studied by light and electron microscopy to assess differences between the cranial, middle and caudal portions. To characterize the potential for cell proliferation of this organ, we used anti-proliferating cell nuclear antigen antibody and anti-Na(+) K(+) -ATPase monoclonal antibody to detect the presence of Na(+) /K(+) pump. In C. paleatus it was observed that cell dynamics showed a decreasing gradient of proliferation in cranio-caudal direction. Also, the intestine of this catfish is an important organ in ionoregulation: the basolateral Na(+) /K(+) pump may have an active role, transporting Na(+) out of the cell while helping to maintain the repose potential and to regulate cellular volume.

Hypothalamic IGF-I gene therapy prolongs estrous cyclicity and protects ovarian structure in middle-aged female rats.

There is substantial evidence that age-related ovarian failure in rats is preceded by abnormal responsiveness of the neuroendocrine axis to estrogen positive feedback. Because IGF-I seems to act as a permissive factor for proper GnRH neuronal response to estrogen positive feedback and considering that the hypothalamic content of IGF-I declines in middle-aged (M-A) rats, we assessed the effectiveness of long-term IGF-I gene therapy in the mediobasal hypothalamus (MBH) of M-A female rats to extend regular cyclicity and preserve ovarian structure. We used 3 groups of M-A rats: 1 group of intact animals and 2 groups injected, at 36.2 weeks of age, in the MBH with either a bicistronic recombinant adeno-associated virus (rAAV) harboring the genes for IGF-I and the red fluorescent protein DsRed2, or a control rAAV expressing only DsRed2. Daily vaginal smears were taken throughout the study, which ended at 49.5 weeks of age. We measured serum levels of reproductive hormones and assessed ovarian histology at the end of the study. Although most of the rats injected with the IGF-I rAAV had, on the average, well-preserved estrous cyclicity as well as a generally normal ovarian histology, the intact and control rAAV groups showed a high percentage of acyclic rats at the end of the study and ovaries with numerous enlarged cysts and scarce corpora lutea. Serum LH was higher and hyperprolactinemia lower in the treated animals. These results suggest that overexpression of IGF-I in the MBH prolongs normal ovarian function in M-A female rats.

Neonatal thymulin gene therapy prevents ovarian dysgenesis and attenuates reproductive derangements in nude female mice.

Congenitally athymic (nude) female mice show severe ovarian dysgenesis after puberty, which seems to be consequential to a number of neuroendocrine derangements described in these mutants. Thus, considerable evidence suggests that thymulin, a thymic peptide, may be involved in thymus-pituitary communication. In order to clarify the relevance of thymulin for the maturation of the female reproductive system, we assessed at hypothalamic, pituitary, ovarian, and uterine level the preventive action of neonatal thymulin gene therapy (NTGT) on the changes that typically occur after puberty in congenitally athymic female mice. We injected (im) an adenoviral vector harboring a synthetic DNA sequence encoding a biologically active analog of thymulin, methionine-serum thymic factor, in newborn nude mice (which are thymulin deficient) and killed the animals at 70-71 d of age. NTGT in the athymic mice restored the serum thymulin levels. Morphometric analysis revealed that athymic nudes have reduced numbers of brain GnRH neurons and pituitary gonadotropic cells as compared with heterozygous controls. NTGT prevented these changes and also rescued the premature ovarian failure phenotype typically observed in athymic nude mice (marked reduction in the number of antral follicles and corpora lutea, increase in atretic follicles). Serum estrogen, but not progesterone, levels were low in athymic nudes, a reduction that was partially prevented by NTGT. Little to no morphological changes were observed in the endometrium of female nudes. The delay in the age of vaginal opening that occurs in athymic nudes was significantly prevented by NTGT. Our results suggest that thymulin plays a relevant physiologic role in the thymus-hypothalamo-pituitary-gonadal axis.

Lectin histochemical aspects of the ovarian lamellae epithelium of Genypterus blacodes (Schneider, 1801) / Padrão de reação lectino-histoquímico do epitélio laminar ovariano em Genypterus blacodes (Schneider, 1801)

The composition and distribution of the glycoconjugates (GCs) secreted by the epithelium of ovarian lamellae with reference to the reproductive biology of Genypterus blacodes (Schneider, 1801) through lectin hi stochemistry is here discussed. In this species, the epithelial cells that line the ovarian cavity presented sharp morphological variations along the reproductive cycle related to the mucus secretion that accompanies oocyte ma turation. During sp awning season, residues of mannose and N-acetylglucosamine were detected in the glycocalyx of those cells using lectinhistochemistry. N- acetylgalactosamine and fucose were also observed in the same zone. The greatest variations in the lectinhistochemical pattern were found in the apical cytoplasm composition in comparison to the basal zone of the cells. The results of the present study were discussed by comparing their possible functional implications.

A composição e distribuição dos glicoconjugados (GCs) secretado pelo epitélio do ovário de lamelas com referência à biologia reprodutiva de Genypterus blacodes (Schneider, 1801) através da histoquímica com lectinas é aqui discutida. Nesta espécie, as células epiteliais que revestem a cavidade do ovário apresentou acentuada variação morfológica ao longo do ciclo reprodutivo relacionados com a secreção de muco que acompanha a maturação do oócito. Durante a época de desova, de resíduos de manose e N-acetilglicosamina foram detectados no glicocálix dessas células usando histoquímica de lectinas. N-acetilgalactosamina e fucose também foram observados na mesma zona. As maiores variações no padrão de lectinas foram encontradas na composição do citoplasma apical, em comparação com a zona basal das células. Os resultados do presente estudo foram discutidos, comparando as suas possíveis implicações funcionais.

Forma e função dos músculos perineais da viscacha (Lagostomus maximus) / Shape and function of the perineal muscles of viscacha (Lagostomus maximus)

Entre as espécies de roedores já estudadas podemos destacar a grande variação na morfologia do aparelho reprodutor masculino. Assim, considerando a importância ecológica dos roedores, e a grande representatividade numérica quanto geográfica destes animais, bem como a escassez que aborda a anatomia reprodutiva, desenvolvemos este trabalho com um roedor histricomorfo da América do Sul, a viscacha. Este animal apresenta algumas características reprodutivas bem peculiares, desta forma descreveremos a anatomia macroscópica da musculatura perineal, e o papel dos músculos no comportamento copulatório desta espécie. A região perineal da viscacha é composta por cinco músculos, sendo que três músculos encontram-se dispostos no diafragama urogenital superficial, Musculus ischiocavernosus, M. bulbocavernosus e M. bulbospongiosus, e pelos músculos que se encontram no diafragma pélvico, M. levator ani e M. retractor penis. Sendo assim, destacamos que o estudo do assoalho pélvico em animais silvestres é de grande valia, uma vez que contribuem com o melhor entendimento dos mecanismos relacionados â ereção e ejaculação; ou seja colaboram com os estudos sobre a reprodução dos animais.

Among the rodent species studied we can highlight the wide variation in the morphology of the male reproductive system. Thus, considering the ecological importance of rodents, and the large number and geographical representation of this animal, as well as shortages regarding the reproductive anatomy, we developed this study with viscacha, a South American histricomorph rodent. As this species has some very peculiar reproductive features, we described the gross anatomy of the perineal muscles and the role of copulatory behavior. The perineal region of viscacha is composed of five muscles, three of which are arranged in the superficial genitourinary diaphragm, as Musculus ischiocavernosus, M. bulbocavernosus and M. bulbospongiosus, and the muscles that lie at the pelvic diaphragm, M. levator ani and M. retractor penis. Therefore, we emphasize that the study of the pelvic floor in wild animals is of great value, then contribute to a better understanding of the mechanisms related to erection and ejaculation or collaborate with studies on the reproduction of animals.

Influence of insulin-like growth factor-binding proteins-2 and -3 in the pathogenesis of cystic ovarian disease in cattle.

Ovarian cysts are one of the major causes of infertility in dairy cows. The development is associated with an endocrine imbalance in the hypothalamo-hypophyseal-gonadal axis in which endocrine factors participate in follicular growth and differentiation and in the secretion of ovarian hormones. Insulin-like growth factor family are essential local regulators of ovarian follicle development and functionality and actions are mediated by binding protein activity. The aim of the present study was to analyze the expression of IGFBP-2 and IGFBP-3 in developing follicles of normal estrous cycling animals and with spontaneous and induced cystic ovarian disease (COD) to determine IGF bioavailability. The mRNA of IGFBP-2 and IGFBP-3 in follicular walls was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. Protein expression was analyzed by immunohistochemistry. The results demonstrated reduced amounts of mRNA of both IGFBPs in the granulosa cells of ovarian follicles of animals with COD (P<0.05). The present study suggests that the IGF system or imbalances between IGFs and IGFBPs may be involved in COD of cattle.

Alternation between dietary protein depletion and normal feeding cause liver damage in mouse.

The effect of frequent protein malnutrition on liver function has not been intensively examined. Thus, the effects of alternating 5 days of a protein and amino acid-free diet followed by 5 days of a complete diet repeated three times (3 PFD-CD) on female mouse liver were examined. The expression of carbonic anhydrase III (CAIII), fatty acid synthase (FAS), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and glutathione S-transferase P1 (GSTP1) in liver were assessed by proteomics, reverse transcriptase-polymerase chain reaction and Northern blotting. The activities of liver GSTs, glutathione reductase (GR) and catalase (CAT), as well as serum glutamic-oxaloacetic transaminase (SGOT) and glutamic-pyruvic transaminase (SGPT) were also tested. Additionally, oxidative damage was examined by measuring of protein carbonylation and lipid peroxidation. Liver histology was examined by light and electron microscopy. Compared with control mice, 3 PFD-CD increased the content of FAS protein (+90%) and FAS mRNA (+30%), while the levels of CAIII and CAIII mRNAs were decreased (-48% and -64%, respectively). In addition, 3 PFD-CD did not significantly change the content of GSTP1 but produced an increase in its mRNA level (+20%), while it decreased the activities of both CAT (-66%) and GSTs (-26%). After 3 PFD-CD, liver protein carbonylation and lipid peroxidation were increased by +55% and +95%, respectively. In serum, 3 PFD-CD increased the activities of both SGOT (+30%) and SGPT (+61%). In addition, 3 PFD-CD showed a histological pattern characteristic of hepatic damage. All together, these data suggest that frequent dietary amino acid deprivation causes hepatic metabolic and ultrastructural changes in a fashion similar to precancerous or cancerous conditions.

Thymic atrophy in cattle poisoned with Solanum glaucophyllum / Atrofia do timo em bovinos intoxicados por Solanum glaucophyllum

Solanum glaucophyllum (Sg) [= S. malacoxylon] is a calcinogenic plant inducing "Enzootic Calcinosis" in cattle. The 1,25-dihydroxyvitamin D3, its main toxic principle, regulates bone and calcium metabolism and also exerts immunomodulatory effects. Thymocyte precursors from bone marrow-derived progenitor cells differentiate into mature T-cells. Differentiation of most T lymphocytes is characterized not only by the variable expression of CD4/CD8 receptor molecules and increased surface density of the T cell antigen receptor, but also by changes in the glycosylation pattern of cell surface glycolipids or glycoproteins. Thymocytes exert a feedback influence on thymic non-lymphoid cells. Sg-induced modifications on cattle thymus T-lymphocytes and on non-lymphoid cells were analysed. Heifers were divided into 5 groups (control, intoxicated with Sg during 15, 30 or 60 days, and probably recovered group). Histochemical, immunohistochemical, lectinhistochemical and morphometric techniques were used to characterize different cell populations of the experimental heifers. Sg-poisoned heifers showed a progressive cortical atrophy that was characterized using the peanut agglutinin (PNA) lectin that recognizes immature thymocytes. These animals also increased the amount of non-lymphoid cells per unit area detected with the Picrosirius technique, WGA and DBA lectins, and pancytokeratin and S-100 antibodies. The thymus atrophy found in intoxicated animals resembled that of the physiological aging process. A reversal effect on these changes was observed after suppression of the intoxication. These findings suggest that Sg-intoxication induces either directly, through the 1,25-dihydroxyvitamin D3 itself, or indirectly through the hypercalcemia, the observed alteration of the thymus.

Solanum glaucophyllum (Sg) [= S. malacoxylon] é uma planta calcinogênica que induz "Calcinose Enzoótica" em bovinos. O 1,25-dihidroxivitamina D3, seu principal agente tóxico, regula o metabolismo ósseo, o metabolismo de cálcio e também mostra efeitos na imunomodulação. Precursores de timócitos derivados da medula óssea se diferenciam em linfócitos T maduros. A diferenciação da maioria dos linfócitos T é caracterizada pela expressão variável de moléculas de receptores CD4/CD8 e densidade aumentada dos receptores antigênicos de superfície de células T. Alem disso, há mudanças no padrão de glicosilação de glicolipídeos na superfície celular ou de glicoproteínas. Timócitos mostram uma influência de retro alimentação em células tímicas não-linfóides. Foram analisadas modificações induzidas pelo Sg em linfócitos T e células tímicas não-linfóides de bovinos. Novilhas foram divididas em 5 grupos (controle, intoxicadas com Sg durante 15, 30 ou 60 dias, e grupo provavelmente recuperado). As diferentes populações celulares das novilhas experimentais foram caracterizadas com técnicas histoquímicas, imuno-histoquímicas, lectina-histoquímicas e morfométricas. As novilhas intoxicadas com Sg mostraram uma atrofia cortical progressiva que foi caracterizada usando a lectina aglutinina de amendoim (PNA) que reconhece timócitos imaturos. Estes animais também aumentaram as células não-linfóides tímicas por unidade de área, detectadas com a técnica de Picrosirius, lectinas WGA e DBA e anticorpos antipancitoqueratina e anti-S-100. A atrofia de timo observada nos animais intoxicados foi semelhante àquela do processo de envelhecimento fisiológico. Após supressão da intoxicação, foi observado um efeito de reversão nestas mudanças. Estes resultados sugerem que a intoxicação por Sg induza a alteração observada no timo diretamente, pela ação de 1,25-dihidroxivitamina D3, ou indiretamente, pela ação da hipercalcemia.

The thymus-neuroendocrine axis: physiology, molecular biology, and therapeutic potential of the thymic peptide thymulin.

Thymulin is a thymic hormone exclusively produced by the thymic epithelial cells. It consists of a nonapeptide component coupled to the ion zinc, which confers biological activity to the molecule. After its discovery in the early 1970s, thymulin was characterized as a thymic hormone involved in several aspects of intrathymic and extrathymic T cell differentiation. Subsequently, it was demonstrated that thymulin production and secretion is strongly influenced by the neuroendocrine system. Conversely, a growing core of information, to be reviewed here, points to thymulin as a hypophysotropic peptide. In recent years, interest has arisen in the potential use of thymulin as a therapeutic agent. Thymulin was shown to possess anti-inflammatory and analgesic properties in the brain. Furthermore, an adenoviral vector harboring a synthetic gene for thymulin, stereotaxically injected in the rat brain, achieved a much longer expression than the adenovirally mediated expression in the brain of other genes, thus suggesting that an anti-inflammatory activity of thymulin prevents the immune system from destroying virus-transduced brain cells. Other studies suggest that thymulin gene therapy may also be a suitable therapeutic strategy to prevent some of the endocrine and metabolic alterations that typically appear in thymus-deficient animal models. The present article briefly reviews the literature on the physiology, molecular biology, and therapeutic potential of thymulin.

Insulin-like growth factor I in sera, ovarian follicles and follicular fluid of cows with spontaneous or induced cystic ovarian disease.

The objective of this research was to determine changes in IGF-I levels in serum and follicular fluid, and immunoreactivity of the follicle wall of cows with spontaneous (slaughter specimens) or ACTH-induced follicular cysts, and to compare results to normal cycling (control) cows after selection of the ovulatory follicle. Concentrations of IGF-I in serum did not differ between control and cystic animals (p=0.76). Fluid from the ovulatory follicle in control cows had 41% higher concentrations of IGF-I than that from cystic follicles collected at slaughter (spontaneous cysts; p<0.05) and 70% higher than that in induced follicular cysts (p<0.05). An intense positive immunostaining with anti-IGF-I was observed in granulosa cells (p<0.05) and in the theca interna (p<0.05) of secondary and tertiary follicles in all three groups of animals, but staining was less intense in cystic (p<0.05) and atretic follicles (p<0.05). This study provides evidence to suggest that cystic ovarian disease in cattle is associated with decreased concentrations of IGF-I in follicular fluid, but not in serum, and decreased production of IGF-I in the follicular wall. These data support the notion that IGF-I plays a role in the regulation of folliculogenesis, and may participate in the pathogenesis of cystic ovarian disease in cattle.