Cutaneous myxosarcoma in a Syrian hamster (Mesocricetus auratus)

The pathological findings in a 2-years-old Syrian hamster (Mesocricetus auratus) with a cutaneous myxosarcoma are described. Grossly, there was a large cutaneous mass in the right cervical region. Microscopical evaluation revealed a myxosarcoma characterized by pleomorphic, fusiform cells loosely arranged, randomly distributed, and presenting a moderate amount of basophilic amorphous stroma. There were hemorrhagic areas within the tumor. The basophilic amorphous stroma was positive to Alcian blue confirming the presence of a mucopolysaccharide matrix. Immunohistochemically, the neoplastic cells expressed vimentin, and were negative for cytokeratin or glial fibrillary acidic protein (GFAP).

Description of the tadpole of Scinax auratus (Wied-Neuwied) (Anura, Hylidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Experimental paracoccidioidomycosis in hamsters (Mesocricetus auratus): Gestational interactions

Paracoccidioides brasiliensis is a dimorphic fungus presenting specific steroid hormone receptors, both in the yeast and mycelial forms and estrogen inhibits the transition from mycelium to yeast. In the acute phase, the disease occurs with equal frequency in both sexes but in adults, females are spared. Placental fungal infection has been reported, but references to fetal infection have not been confirmed. We used 78 Syrian female hamsters divided into 3 groups: GI consisted of 30 infected mated females, GII of 20 infected unmated females and GIII of 28 uninfected mated females. Animals of group I were mated 4 weeks after infection and half of them were submitted to cesarean section on day 15 after successful mating; the other half was maintained and submitted to cesarean section and sacrificed 14 weeks after infection. Half of the animals of group II were sacrificed seven weeks and the other half 14 weeks after infection. Uninfected animals of group III were treated the same as the animals of group I. The animals were infected with strain 18 of P. brasiliensis by the intracardiac route. We evaluated the disease by the volume of granulomas in different organs, number of fungi in liver and spleen and the immunologic responses [ELISA, Double Immunodifusion (DID), Delayed Hypersensitivity Skin Test (DHT) and Macrophage Migration Inhibition (MMI)]. We studied the infection through the gestation by evaluation of the abortions, morphologic and clinic examinations of the fetuses. Our results showed that the infection did not transfer to the fetus through the placenta, but the number of abortions was larger among infected females. The newborns of GI females were smaller, weighed less and showed little vitality. The disease was more severe and disseminated in infected mated females, especially in the second sacrifice 14 weeks after inoculation, when the total volume of granulomas in them (56.3 mm) was much greater than in the infected unmated females (12 mm).

Considerations sur la ramification de L'aorte abdominale du hamster (Mesocricetus Auratus)

The disposition of the abdominal aorta branching in Mesocricetus auratus is described, establishing variation groups with relation to the celiac, cranial mesenteric, renal, genital and caudal mesenteric arteries. Sixty animals (30 males and 30 females) of different ages and weights, were anesthetized with chloroform, injected with contrasting substance in the abdominal aorta (50 animals with Neoprene latex and 10 with a radioopaque mass), after which they were dissected with the help of a stereoscopic microscope. The animals with radioopaque masses were radiographed in comparison with the other animals. The results are expressed in relative percentage figures and compared with other mammalian arterial dispositions.

Fine structure of the ductuli efferentes of the hamster (Mesocricetus auratus).

Structurally the ductuli efferentes of the hamster showed 2 distinct segments, a testicular and an epididymal. Both of these segments were lined by a pseudostratified epithelium, which showed basically non-ciliated and ciliated cells. In the testicular segment a 3rd type of oval dark cells was observed. The ultrastructural characteristics of these cells were presented and discussed in this report.

Complexo enzimático na dieta de alevinos de kinguio (Carassius auratus)

Aiming to evaluate the enzymatic complex supplementation in diets for goldfish fingerlings (Carassius auratus), 240 fish weighing initially 1,36 ± 0,02g, randomly distributed in 20 tanks with 150L, in four treatments and five replications, with twelve fish in each experimental unit were used. The fish were fed at 8:00 and 11:00 a.m. and 2:00 and 5:00 p.m. with diets containing different inclusion levels (0; 0,033; 0,066 e 0,099%) of enzymatic complex (amilase, protease, celulase, lipase, â-glucanase and phytase), and formulated with 32,36% of digestible protein and 3.023kcal of digestible energy kg-1. There were no differences observed (P>0,05) in the mean final weight, weight gain, total length, standard length, survival and carcass composition. However, the fish apparent feed conversion was impaired by the supplementation of enzymatic complex with 0,099% in diet. The use of enzymatic complex does not provides benefits in the productive performance for goldfish fingerlings.

Estudo comparativo entre os aspectos clínicos, histopatológicos e das regiões organizadas nucleolares pela impregnação pela prata(AgNOR)na evolução do carcinoma epidermóide(CE) quimicamente induzido por 9,10- dimetil-1,2-benzantraceno (DMBA) em língua de hamsteres sírios dourados(Mesocricetus auratus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preferência por substratos escuros no C. auratus: influência das condições de luz no alojamento

Pós-graduação em Psicologia do Desenvolvimento e Aprendizagem - FC

Expressão da proteína nuclear de proliferação celular (PCNA), da B-Catenina e do Agnor, na etapa inicial do processo de carcinogênese quimicamente induzido pelo DMBA, em borda lateral de língua de hamsters sírio dourado(Mesocricetus auratus)

The oral cancer model in hamsters shows many simílarities with developmental oral cancer in humans. The proliferating capacity is one the most characteristics of neoplásica ce/Is and detection of these ce/Is allow us, throughout of its counting, to achieve an estimated tumour growing index, with a consequent repercussion about prognostic and in the treatment of those lesions. 40 golden Syrian hamsters, both genders, aged between two to six mouth and weight 150g in average were used. The left síde of tangue of each animal was painted for eight consecutive weeks, with a solution of DMBA. Tongues were removed, fixed in 10% buffered fonnal solution. The histological slides were stained by AgNOR technique and by PCNA and β-catenin immunohistochemical antibodies. Statistical analyzes were performed by ANOVA one-way test and Tukey test. We may conclude that an association between AgNOR and PCNA might indicate the higher proliferating activity of the analyzed celIs. The experimental carcinogenesis model in hamster tongue is an available methodology for immunohistochemistry study. And finally, PCNA and β-catenin immunohistochemical antibodies may be used to analyze possible premalignant areas in oral leukoplakia

Suplementação de vitamina A em dietas para Kinguios (Carassius auratus)

Vitamin A is important to the proper development and functioning of the body, appearing in several metabolic functions. This experiment was conducted with aim evaluate to the vitamin A supplementation in diets for Goldfish Carassius auratus. The experimental was completely randomized with six treatments (0, 2.000, 4.000, 8.000, 16.000 and 32.000 IU of vitamin A kg(-1) diet) with four repetitions into 24 experimental cages, with capacity for 150 liters useful volume, made of mesh shading, installed inside a masonry circular tank with a capacity of 25 m(3) of water. 192 fish with an average initial weight of 6.66 +/- 0.57 g and initial length of 7.30 +/- 0.33 cm, feed at 8h, 11h, 14h and 17h at satiety were used. Evaluated the effects on productive performance and intensity of yellow-red coloring of the skin of the fish were. The Linear Response Plateau analysis of weight gain and length total, feed conversion and daily growth rate versus vitamin A requirement estimate showed 2,624, 2,385 and 2,358, 4,381 and 2,866 IU of vitamin A per kg diet, respectively. The data indicated that this vitamin has little or no influence on the intensity of the skin color of the Goldfish.

GRANULOMATOUS REACTION IN THE HAMSTER-CHEEK POUCH INDUCED BY KILLED PARACOCCIDIOIDES-BRASILIENSIS

We have studied the role of Paracoccidioides brasiliensis viability in the morphology of paracoccidioidomycotic granulomas in the hamster cheek pouch, an immunologically privileged site. Naive (N = 75) and previously sensitized (N = 50) two-month old male hamsters (Mesocricetus auratus) were inoculated into the pouch with 5 x 10(5) live or heat- or formalin-killed fungi. Previously sensitized animals presented a positive footpad test and immunodiffusion demonstrable antibodies (titer 1/32), at the time of sacrifice; naive animals were always negative for those immunological tests. The histological results showed that, like viable P. brasiliensis, killed fungi evoke typical epithelioid granulomas in 100% of animals, even in the absence of immunodiffusion or footpad test detectable immune response. The granulomas elicited by killed fungi were devoid of giant cells or a mononuclear cell halo, suggesting that live proliferating fungi or their products may be involved in these events.

WATER BALANCE and SPATIAL DISTRIBUTION of AN ANURAN COMMUNITY FROM BRAZIL

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of Ketoconazole on experimental paracoccidioidomycosis in the Syrian hamster: immunological and histopathological study

The effect of Ketoconazole (KTZ) on the hamster experimental intratesticular paracoccidioidomycosis was studied employing different treatment schedules. KTZ long course treatment beginning at an early stage of the infection was effective in preventing fungal proliferation, dissemination to lymph nodes, spleen and kidneys, and in maintaining low levels of humoral and cellular specific immune responses. KTZ short course treatment starting at an advanced stage of disease resulted in a more severe histopathological picture without significant changes in the immunological profile. The drug prolonged the life span of hamsters infected with Paracoccidioides brasiliensis, but did not prevent mortality. Toxic necrosis of the bone marrow occurred in normal animals receiving 120 mg/kg/day of KTZ but with lower doses no morphologic alterations were observed in heart, lungs, kidneys, adrenals, spleen, liver, intestine or bone marrow. © 1984 Dr W. Junk Publishers.

Increased natural killer activity does not prevent progression of experimental kala-azar

Kala-azar is the visceral form of leishmaniasis and it is caused by intracellular parasites from the complex Leishmania donovani. Golden hamster (Mesocricetus auratus) infected with Leishmania donovani develop a disease very similar to human Kala-azar. There is conspicuous hipergammaglobulinaemia and their T cells do not respond to stimulation with parasite antigens. We used this experimental model to evaluate the natural killer (NK) activity during the initial phase of the disease. Outbred hamsters infected by intravenous route with 5.106 amastigotes of L. donovani 1S showed a concurrent increase in the spleen weight and in the spleen cell number. Using the single cell assay we detected a significant increase in the percentage of NK effector cells on the 4th day of infection. Imprints from spleen and liver showed at days 14 and 28 a significant increase in the parasite burden. These results show that the increased NK activity in the beginning of the infection was not able to restrain the progression of the disease in this experimental model.

Revision of the South American freshwater genus Plagioscion (Teleostei, Perciformes, Sciaenidae)

The South American freshwater sciaenid genus Plagioscion is reviewed. Five of the 15 nominal species assigned to the genus are considered to be valid: Plagioscion squamosissimus, widely distributed in Atlantic drainages east of the Andes; P. auratus from the Río Orinoco and Río Amazonas basins; P. magdalenae from the Río Magdalena and Río Amazonas basins; P. ternetzi from the lower Río Paraná, Río Paraguay and Rio Uruguay basins; and P. montei from the Río Amazonas basin. Copyright © 2005 Magnolia Press.