Aspectos anatômicos do olho e neuroquímicos da retina do mocó (Kerodon rupestris)

The visual system is an important link between the animal and the environment, com profound influences on the habits and lifestyle in various habitats. Adaptive mechanismsto the temporal niche are present in the visual system of many vertebrates, involving changins in ocular dimensios and design, retinal cell distribution and organization of neurochemical circuits related to the retinal resolution or sensitivity. The sensory system of the eye is represented by the retina, whose organization is responsible by receipty, initial analysis, and transmission of the information to the brain. The knowledge of the position of the eyes in the head and the distribution of retinal cells allow to identify adaptive aspects of each species to its visual field, which is characteristic to the ecological niche it occupies. In this research, we study eye anatomical characteristics and retina neurochemical features of the rock cavy (Kerodon rupestris), a tipical Brazilian rodent from the suborder Hystricomorpha, family Caviidae. The rock cavy has lateral eyes well constitute bony orbit and well differentiated extrinsic muscle. The study of the descriptive and morphometric anatomy of the showed mean values of axial diameter 10.7±0,5mm and equatorial diameter 11.6±0.7mm. The pupil is slit shaped and the lens has mean axial diameter 5.4±0.03 mm, corresponding to ~45% of the axial diameter of the eye. The posterior nodal distance and the retinal magnification factor were estimated at 6.74 mm e 118 μm/grau, respectively. Flat mounts were processed for Nissl stain, and the topographic distribution of ganglion cells showed a moderate visual band, just below the optic disc, with higher density in the ventral retina. Retinal vertical sections and flat mounts were processed for immunohistochemistry to visualize tyrosine hydroxilase (TH) and thus two types of TH+ cells were detected. Type 1 cells had strong TH-immunoreactivity, the body cell varied from 120.047 to 269.373 μm2 stratifying in the sublamina 1 of the IPL. Type 2 cells were weakly TH-imunoreactive, had cell body located mostly in the IPL, varying from 54.848 to 177.142 μm2, constituting ~10% of the TH+ cells. Both cell types exhibited similar topographic distribution with higher density found in a horizontal band along of the naso-temporal axis in the dorsal retina. The total population of dopaminergic cells was 2,156±469,4 cells, occupying an average area of 198,164 μm2. The presence of cones and rods was detected by immunohistochemistry in vertical sections and flat mounts. S cones density is around 10 times smaller than L cones, with different degree of spatial organization. Other retinal neuronal populations of the rock cavy were also detected in vertical sections with specific markers. Comparative analysis of the anatomical characteristics of the rock cavy eye 12 suggest that it was designed to acquire higher sensitivity to light, at expense of image sharpness, compatible with a vision at mesopic conditions. Additionally, the distribution of the 2 subtypes of dopaminergic cells in a naso-temporal band in the dorsal retina seems suitable to a gain in sensitivity, coherent with an animal with predominantly crepuscular activity pattern

O jogo de RPG como ferramenta auxiliar de aprendizagem na disciplina de Ciências

ON reflecting the traditional teaching approach, characterized by non-dynamic and descriptive methods that still persists in schools at the present time, associated to social living enrichment has motivated the search for new techniques to stimulate students in the process of teaching, such as roleplaying games, known as RPG, already being used in various school disciplines. Considering the amount of themes in general sciences and in biology, in particular that could be explored through RPG our purpose was to develop a game to be used as a learning complementary tool. PANGÉIA, the game we developed, was based on the GURPS system and to be placed at the geological Eras of the earth. The objective of the game was playing a character that represented an animal belonging to a Class of Vertebrates, and making it surviving and reproducing during risky situations presented in the game. These situations were narratives by the Master about challenges that the character would face, which should be solved using the dices. Along the narrative, the Master introduced concepts and informations about the subject being studied. To evaluating how the game worked out, we solicited 11 volunteers, from two different schools in Natal, to play PANGÉIA. Before starting the game, and without knowing the final objectives of our project, the volunteers answered a general questionnaire to let us know their level of knowledge, which was also answered after playing the game. The comparison of the volunteers answers before and after playing the game suggests that this activity influenced them. Also, based on this test, we identified critical aspects to be modified in PANGÉIA, specially a stronger relation between both the questionnaire and the game placement with the narrative of the master. In order to have PANGÉIA used as a complementary learning tool, a teachers handbook has to be written, including rules concerning the format of game application. Nonetheless, based on this pilot study, we conclude that topics on sciences and biology can be easily adjusted to RPG format, and its flexibility provides multiple combinations that can be used to help learning the more difficult topics to be taught in a class

O efeito inimigo íntimo é aplicável a Dinoponera quadríceps (Hymenoptera, Formicidae)?

Food access, territory or reproductive partner can generate conflicts between individuals in many species with occurrence of aggressive behaviors. However some species respond less aggressively to intrusion by neighbors than non-neighbors in its territory to minimize the costs of continuous fight. This difference in aggression is called Dear Enemy Effect described in various vertebrates and invertebrates. To investigate if this phenomenon occurs in Dinoponera quadriceps (Hymenopetra, Formicidae) three colonies, two neighbors and one non-neighbor, were captured in its natural environment then transfered to the laboratory where we did experimental confrontation intra and inter colonies involving one pair of workers. We compared the behavioral frequency exhibited by each worker, the intensity and duration of the confrontation between a neighbor and a non-neighbor referring the place where they were collected. Our results revealed that Dear Enemy Effect does not apply to D. quadriceps due aggressive response is more intense and longest toward neighbor than non-neighbor, probably due intra specific competition, ecological factors and characteristic of the species

Coati (Nasua nasua) Attacks on Humans: Case Report

Coatis [including Nasua nasua, the ring-tailed coati], are medium-sized mammals widely distributed in the Americas. They are social animals, whose normal diet includes insects, fruits, and small vertebrates, and rarely prey on larger sized animals. There are, to our knowledge, no reports in the medical literature of attacks on humans. This report describes a coati attack on 2 children in their home. The children sustained deep scratches and bites. The animal may have injured the humans in a defensive strike, but motivation for attack was uncertain. Coati attacks may occur in places where there is interaction between these mammals and humans.

Tropical dermatology: Marine and aquatic dermatology

Dermatoses caused by marine organisms are frequently seen in dermatology clinics worldwide. Cutaneous injuries after exposure to marine environments include bacterial and fungal infections and lesions caused by aquatic plants and protists. Some of these diseases are well known by dermatologists, such as Vibrio vulnificus septicemia and erysipeloid, but others are uncommon, such as envenomation caused by ingestion or contact with certain dinoflagellates or cyanobacteria, which are associated with rashes that can begin Within minutes after exposure. Many marine/aquatic invertebrates, such as sponges, cnidarians, echinoderms, crustaceans, and mollusks, are associated with different kinds of dermatologic lesions that call vary from irritant or allergic contact dermatitis to physical trauma and envenomations. These cutaneous lesions May result in mild local reactions or can be associated with severe systemic reactions. Invertebrate animals, such as cnidarians, sea urchins, and worms, and aquatic vertebrates, such as venomous fishes and stingrays, are commonly associated with skin lesions in many countries, where they call constitute occupational dermatoses among fishermen and scuba divers, but they can also be observed among persons who contact these animals in kitchens or beaches. The presence of unusual lesions, a recent travel history, and/or a report of contact with an aquatic environment (including ownership of a marine or freshwater aquarium) should alert the dermatologist to the etiology of the cutaneous problems. (J Am Acad Dermatol 2009;61:733-50.)

Risk factors and presence of antibodies to Toxoplasma gondii in dogs from the coast of São Paulo State, Brazil

A toxoplasmose é causada por um protozoário parasita intracelular obrigatório, Toxoplasma gondii, e acomete vertebrados homeotérmicos incluindo animais de companhia e o homem. O cão apresenta importância epidemiológica por atuar como sentinela da infecção para o homem. O presente estudo objetivou determinar a ocorrência de anticorpos para T. gondii em 205 amostras de soro de cães do município de Ubatuba, SP, Brasil, pela reação de imunofluorescência indireta (RIFI), assim como os fatores de risco relacionados à infecção nos animais, como raça, idade, sexo, acesso a rua, ingestão de comida caseira, acesso a água não tratada e presença de roedores. 52/205 (25,4%) amostras foram positivas para toxoplasmose, com títulos variando de 16 a 256. Os resultados sorológicos apresentaram associação significativa (P<0,05) com consumo de comida caseira (45/118; 38,1%; IC95% 29,9%-47,2%) (OR=7,0; CI95% 3,0-16,6), e acesso a rua, em que aqueles que não tinham acesso a rua foram prevalentes (37/121; 30,6%; IC95% 23,1%-39,3%) (OR=0,5; CI95% 0,2-1,0). Estes resultados demonstram que a toxoplasmose na região está relacionada com problema de educação sanitária, principalmente quanto ao adequado cozimento dos alimentos, visto que a maioria dos animais positivos não apresentou associação significativa com presença de roedores ou consumo de água não tratada, porém os mesmos permaneciam em casa aos quais fora oferecida comida caseira. Portanto, a toxoplasmose consiste em um problema de saúde pública na região estudada, sendo necessárias medidas sanitárias para o controle da infecção, visto a estreita relação homem-cão e os fatores de risco presentes.

Seroprevalence of Toxoplasma gondii infection in cats from Curitiba, Paraná, Brazil

A toxoplasmose é uma zoonose de distribuição mundial, causada pelo protozoário Toxoplasma gondii que infecta os vertebrados de sangue quente. Este estudo objetiva estabelecer a prevalência de anticorpos anti-Toxoplasma gondii e o estudo de associação em uma população de gatos domésticos atendidos em uma clínica veterinária exclusiva de gatos localizada em Curitiba, estado do Paraná, Brasil. As amostras de soro foram obtidas e processadas pela reação de imunofluorescência indireta IgG. Títulos de anticorpos foram encontrados em 46/282 (16,3%) das amostras analisadas, com título de 16 em oito gatos, 64 em 23, 256 em 14 e 1024 em um gato. Diferenças estatísticas não foram encontradas no estudo de associação entre idade, gênero e região da cidade (p > 0,05). Nenhuma diferença significativa foi encontrada para qualquer variável, quando comparando a soropositividade com a ocorrência do possível fator de risco. A soroprevalência foi relativamente menor quando comparada a outras regiões brasileiras, provavelmente por serem gatos de proprietários, que tinham hábito domiciliado e alimentação restrita baseada em alimentos industrializados, com acesso restrito a rua e sem acesso a caça. em conclusão, a baixa soroprevalência de toxoplasmose felina pode estar relacionada a gatos com proprietários devido aos cuidados alimentares e acesso restrito à rua, e também pode estar associada à baixa exposição ambiental local

Differential expression of myogenic regulatory factor MyoD in pacu skeletal muscle (Piaractus mesopotamicus Holmberg 1887: Serrasalminae, Characidae, Teleostei) during juvenile and adult growth phases

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Telomere biology of trypanosomatids: beginning to answer some questions

Studies of telomere structure and maintenance in trypanosomatids have provided insights into the evolutionary origin and conservation of some telomeric components shared by trypanosomes and vertebrates. For example, trypanosomatid telomeres are maintained by telomerase and consist of the canonical TTAGGG repeats, which in Trypanosoma brucei can form telomeric loops (t-loops). However, the telomeric chromatin of trypanosomatids is composed of organ ism-specific proteins and other proteins that share little sequence similarity with their vertebrate counterparts. Because telomere maintenance mechanisms are essential for genome stability, we propose that the particular features shown by the trypanosome telomeric chromatin hold the key for the design of antiparasitic drugs.

Lingüística de interações moleculares

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cytochemical characterization of eosinophilic leukocytes circulating in the blood of the turtle (Chrysemys dorbignih)

Eosinophils and neutrophils are granulocytic leukocytes that are present in the blood of most vertebrates. Studies have been performed on lower vertebrates to understand the biological roles of the cells in defense mechanisms and to establish phylogenetic studies and new experimental models. Whether these 2 cell types exist in reptiles is a matter of controversy. In the blood of turtles there are 2 types of granulocytes that exhibit eosinophilia, one of them with round cytoplasmic granules and the other with elongated cytoplasmic granules. It has been suggested that these cells may be eosinophils in different stages of maturation but they also may be distinct cell types, i.e. eosinophils and neutrophils. In the present study, we characterized the 2 types of granulocytes that are present in the blood of Chrysemys dorbignih, using cytochemical techniques. Type I eosinophils showed activity of nonspecific esterase, peroxidase activity that is resistant to KCN, and basic proteins. Type II eosinophils exhibited activity of trimetaphosphatase, alkaline phosphatase, nonspecific esterase, peroxidase that is sensitive to KCN, and basic proteins. These observations indicate the existence of 2 distinct cell types in the blood of Chrysemys dorbignih, type I and type II eosinophils, that correspond to eosinophils and heterophils (neutrophils) of mammals and other vertebrates.

Nitric oxide synthase activity in tissues of the blowfly Chrysomya megacephala (Fabricius, 1794)

Although insects lack the adaptive immune response of the mammalians, they manifest effective innate immune responses, which include both cellular and Immoral components. Cellular responses are mediated by hemocytes, and Immoral responses include the activation of proteolytic cascades that initiate many events, including NO production. In mammals, nitric oxide synthases (NOSs) are also present in the endothelium, the brain, the adrenal glands, and the platelets. Studies on the distribution of NO-producing systems in invertebrates have revealed functional similarities between NOS in this group and vertebrates. We attempted to localize NOS activity in tissues of naive (UIL), yeast-injected (YIL), and saline-injected (SIL) larvae of the blowfly Chrysomya megacephala, using the NADPH diaphorase technique. Our findings revealed similar levels of NOS activity in muscle, fat body, Malpighian tubule, gut, and brain, suggesting that NO synthesis may not be involved in the immune response of these larval systems. These results were compared to many studies that recorded the involvement of NO in various physiological functions of insects.

Germ line Cysts and the Formation of the Germinal Epithelium During the Female Gonadal Morphogenesis in Cyprinus Carpio (Teleostei: Ostariophysi: Cypriniformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Organization of Repeated DNA Elements in the Genome of the Cichlid Fish Cichla kelberi and Its Contributions to the Knowledge of Fish Genomes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The 5S rDNA family evolves through concerted and birth-and-death evolution in fish genomes: an example from freshwater stingrays

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)