| retinal ganglion cells in the south american opossum (didelphis aurita). | by using the golgi technique, the authors investigated the morphology of ganglion cells in the retinas of south american opossums. in flat-mount preparations of the retinas, cell bodies, entire dendritic fields, and the stratification level of ganglion cells were studied. fractal dimensions of dendritic trees, an objective quantitative measure of morphological complexity, were included as a morphological parameter of classification. based on these characteristics, nineteen types of ganglion cell ... | 2000 | 10701444 |
| investigations into the source of binocular input to the nucleus of the optic tract in an australian marsupial, the wallaby macropus eugenii. | recordings from direction-selective neurons in the nucleus of the optic tract (not) of the marsupial wallaby, macropus eugenii, show that 53% of cells are sensitive to visual stimulation of both eyes. anatomical tracing studies using horseradish peroxidase reveal many retinal terminals in the contralateral not but very few in the ipsilateral nucleus. there was no convincing evidence of cortical inputs to the ipsilateral not despite large injections of tracer into the visual cortex. during visual ... | 2002 | 12373372 |
| peridomiciliary colonies of triatoma vitticeps (stal, 1859) (hemiptera, reduviidae, triatominae) infected with trypanosoma cruzi in rural areas of the state of espírito santo, brazil. | in brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. in areas of atlantic forest such as in the brazilian state of espírito santo, there are no species adapted to live in human habitations. the few autochthonous cases of chagas disease encountered in espírito santo have been attributed to adult specimens of triatoma vitticeps that invade houses from forest remnants. in recent years, the entomology unit of the espír ... | 2005 | 16184222 |
| natural infection, transovarial transmission, and transstadial survival of rickettsia bellii in the tick ixodes loricatus (acari: ixodidae) from brazil. | an ixodes loricatus engorged female, infected with rickettsia bellii, was collected from an opossum (didelphis aurita) in mogi das cruzes, são paulo state, brazil. two consecutive laboratory tick generations (f(1) and f(2)) reared from this single engorged female were evaluated for rickettsia infection by polymerase chain reaction (pcr) targeting specific rickettsia genes. immature ticks fed on naïve wistar rats (rattus norvegicus) and adult ticks fed on opossum (d. aurita), both free of ticks a ... | 2006 | 17114723 |
| small mammal populations of an agroecosystem in the atlantic forest domain, southeastern brazil. | this study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. the study was conducted in a rural area of the atlantic forest, in sumidouro, rio de janeiro state, brazil. the population sizes, age structure and reproduction were studied for the four most common species in the study area. the overall diversity was 1.67 and ranged between 0.8 to 1.67. the species richness was 13 considering the whole study. the most abundant species wer ... | 2007 | 17505767 |
| eimeria auritanensis n. sp. and e. gambai carini, 1938 (apicomplexa: eimeriidae) from the opossum didelphis aurita wied-newied, 1826 (marsupialia: didelphidae) from southeastern brazil. | two eimerid species are described from the opossum didelphis aurita from southeastern brazil. eimeria auritanensis n. sp. sporulated oocysts spherical to subspherical (31.55 +/- 1.56 by 29.55 +/- 1.40 microm), shape index 1.07; oocyst wall double layered 2.10 +/- 0.27 microm thick, outer yellowish and strongly ornamented having a prominently mammillated surphace; inner layer smooth and brownish. there is no micropyle or oocyst residuum, but one or two polar granules are present. sporocysts ovoid ... | 2007 | 17706009 |
| characterization of trypanosoma cruzi isolated from humans, vectors, and animal reservoirs following an outbreak of acute human chagas disease in santa catarina state, brazil. | during march 2005, 24 cases of acute human chagas disease were detected in santa catarina state, southern brazil, all of them related to the ingestion of trypanosoma cruzi-contaminated sugar cane juice. following field studies allowed the isolation of 13 t. cruzi strains from humans, opossums (didelphis aurita and didelphis albiventris), and vectors (triatoma tibiamaculata). the isolated strains were characterized by multilocus enzyme electrophoresis (mlee) and analysis of the spliced-leader and ... | 2008 | 17889480 |
| experimental infection of opossums didelphis aurita by rickettsia rickettsii and evaluation of the transmission of the infection to ticks amblyomma cajennense. | the present study evaluated the infection of opossums (didelphis aurita) by rickettsia rickettsii and their role as amplifier hosts for horizontal transmission of r. rickettsii to amblyomma cajennense ticks. three groups of opossums were evaluated: on day 0, group 1 (g1) was inoculated intraperitoneally with r. rickettsii; group 2 (g2) was infested by r. rickettsii-infected ticks; and group 3 (g3) was the uninfected control group. opossum rectal temperature was measured daily. blood samples were ... | 2008 | 18945194 |
| body size of commom opossum didelphis aurita wied-neuwied 1826 (didelphimorphia: didelphidae) on southern brazilian islands. | the body size of vertebrates isolated on islands can undergo changes due to ecological features of these environments. this study aimed to compare the body size of the common opossum, didelphis aurita, from different insular populations within the same archipelago in southern brazil. the opossum populations showed corporal variation and different hypotheses were raised to understand the results. this study constitutes the most detailed body size comparison of a marsupial within different insular ... | 2009 | 19675932 |
| life cycle of ixodes luciae (acari: ixodidae) in the laboratory. | the life cycle of ixodes luciae was evaluated for five consecutive generations in the laboratory. wild mice calomys callosus and laboratory rats rattus norvegicus were used as hosts for larvae and nymphs. for adult ticks, opossums didelphis aurita were used as hosts. off-host developmental periods were observed in an incubator at 27 degrees c and 95% rh. the life cycle of i. luciae lasted 95-97 days, excluding prefeeding periods. c. callosus, one of the natural host species for i. luciae immatur ... | 2009 | 19756745 |
| sarcocystis lindsayi-like (apicomplexa: sarcocystinae) of the opossum (didelphis aurita) from southeastern brazil. | sporocysts of sarcocystis were obtained from intestinal scrapings of three out of five opossums (didelphis aurita) trapped in the southeastern region, of the state of rio de janeiro, brazil. fifteen caged budgerigars (melopsittacus undulatus) received, orally, twenty-six sporocysts in 500 ml pbs, but only five belonging to one of the groups developed clinical signs, that consisted of anorexia, lethargy, ruffled feathers and dyspnoea, and parasitism in tissues. two of the five budgerigars died on ... | 2008 | 20059875 |
| experimental infection of the opossum didelphis aurita by rickettsia felis, rickettsia bellii, and rickettsia parkeri and evaluation of the transmission of the infection to ticks amblyomma cajennense and amblyomma dubitatum. | this work evaluated the infection of opossums (didelphis aurita) by rickettsia felis, rickettsia bellii, and rickettsia parkeri and their role as amplifier hosts for horizontal transmission to amblyomma cajennense and/or amblyomma dubitatum ticks. infection in d. aurita was induced by intraperitoneal inoculation with r. felis (n = 4 opossums), r. bellii (n = 4), and r. parkeri (n = 2). another group of six opossums were inoculated intraperitoneally with leibovitz-15 sterile culture medium, repre ... | 2010 | 20455783 |
| isolation and genetic characterisation of toxoplasma gondii from a red-handed howler monkey (alouatta belzebul), a jaguarundi (puma yagouaroundi), and a black-eared opossum (didelphis aurita) from brazil. | toxoplasma gondii isolates are highly diverse in domestic animals from brazil. however, little is known about the genetics of this parasite from wild mammals in the same region. reveal genetic similarity or difference of t. gondii among different animal populations is necessary for us to understand transmission of this parasite. here we reported isolation and genetic characterisation of three t. gondii isolates from wild animals in brazil. the parasite was isolated by bioassay in mice from tissu ... | 2010 | 21055880 |
| rickettsia in synanthropic and domestic animals and their hosts from two areas of low endemicity for brazilian spotted fever in the eastern region of minas gerais, brazil. | the aim of this study was to understand the current epidemiology of rickettsial diseases in two rickettsial-endemic regions in brazil. in the municipalities of pingo d'agua and santa cruz do escalvado, among serum samples obtained from horses and dogs, reactivity by immunofluorescent assay against spotted fever group rickettsiae was verified. in some serum samples from opossums (didelphis aurita) captured in santa cruz do escalvado, serologic response against rickettsiae was also verified. polym ... | 2010 | 21118939 |
| permanent genetic resources added to molecular ecology resources database 1 may 2009-31 july 2009. | this article documents the addition of 512 microsatellite marker loci and nine pairs of single nucleotide polymorphism (snp) sequencing primers to the molecular ecology resources database. loci were developed for the following species: alcippe morrisonia morrisonia, bashania fangiana, bashania fargesii, chaetodon vagabundus, colletes floralis, coluber constrictor flaviventris, coptotermes gestroi, crotophaga major, cyprinella lutrensis, danaus plexippus, fagus grandifolia, falco tinnunculus, fle ... | 2009 | 21564933 |
| biological, biochemical and molecular features of trypanosoma cruzi strains isolated from patients infected through oral transmission during a 2005 outbreak in the state of santa catarina, brazil: its correspondence with the new t. cruzi taxonomy consensus (2009). | we examined strains of trypanosoma cruzi isolated from patients with acute chagas disease that had been acquired by oral transmission in the state of santa catarina, brazil (2005) and two isolates that had been obtained from a marsupial (didelphis aurita) and a vector (triatoma tibiamaculata). these strains were characterised through their biological behaviour and isoenzymic profiles and genotyped according to the new taxonomy consensus (2009) based on the discrete typing unities, that is, t. cr ... | 2011 | 22241116 |
| natural infection of didelphis aurita (mammalia: marsupialia) with leishmania infantum in brazil. | the opossum didelphis have been considered as natural hosts of leishmania parasites in the new world, suggesting an important role in the epidemiology of visceral leishmaniasis (vl). among six extant species that belong to the genus didelphis, only two (d. marsupialis and d. albiventris), have been mentioned as natural hosts of leishmania infantum in brazil and colombia. in the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues o ... | 2012 | 22676324 |
| detection of hantavirus in bats from remaining rain forest in são paulo, brazil. | the significant biodiversity found in brazil is a potential for the emergence of new zoonoses. study in some places of the world suggest of the presence to hantavirus in tissues of bats. researches of hantavirus in wildlife, out rodents, are very scarce in brazil. therefore we decided to investigate in tissues of different species of wild animals captured in the same region where rodents were detected positive for this virus. the present work analyzed ninety-one animals (64 rodents, 19 opossums, ... | 2012 | 23259834 |
| serological evidence of exposure to tick-borne agents in opossums (didelphis spp.) in the state of são paulo, brazil. | this work involved a serological investigation of tick-borne pathogens in opossums in eight municipalities of the state of são paulo, brazil. serum samples from 109 opossums (91 didelphis aurita and 18 didelphis albiventris) were tested to detect antibodies to rickettsia rickettsii (taiaçu strain, 1:64 cut-off) and ehrlichia canis (são paulo strain, 1:40 cut-off), by indirect immunofluorescence assay (ifa); and against borrelia burgdorferi (strain g39/40) by enzyme-linked immunosorbent assay (el ... | 2016 | 27276663 |
| lungworm heterostrongylus heterostrongylus travassos, 1925 from the black-eared opossum in south america: morphologic, histopathological and phylogenetic aspects. | nematode parasites of the cardiopulmonary system of livestock and pet animals have been receiving attention due to the pathogenic effects they produce in the course of the infection. however, parasitism in wild animals by metastrongilid nematodes has been neglected, resulting in potential risk to wildlife. heterostrongylus heterostrongylus is the etiological agent of bronchial pneumonia in the black-eared opossum, didelphis aurita, a widely distributed marsupial frequently reported to inhabit ar ... | 2016 | 27692317 |
| leishmania spp. in didelphis spp. from northeastern brazil. | the synanthropic behavior of marsupials of the genus didelphis in endemic areas of leishmaniasis suggests that these animals may play an important role in the epidemiology of this infection. the aim of the present study was to detect leishmania spp. dna in didelphis albiventris (white-eared opossum) and didelphis aurita (big-eared opossum) living in forested and peridomestic areas of northeastern brazil. blood samples were collected from 25 animals (23 d. albiventris and 2 d. aurita ) by cardiac ... | 2016 | 27691942 |
| molecular characterization and development of sarcocystis speeri sarcocysts in gamma interferon gene knockout mice. | the north american opossum (didelphis virginiana) is the definitive host for at least three named species of sarcocystis: sarcocystis falcatula, sarcocystis neurona and sarcocystis speeri. the south american opossums (didelphis albiventris, didelphis marsupialis and didelphis aurita) are definitive hosts for s. falcatula and s. lindsayi. the sporocysts of these sarcocystis species are similar morphologically. they are also not easily distinguished genetically because of the difficulties of dna e ... | 2015 | 26303093 |
| didelphis aurita (marsupialia: didelphidae): a new host for sarcocystis lindsayi (apicomplexa: sarcocystidae). | nine opossums, didelphis aurita , were captured in the city of seropédica, state of rio de janeiro, brazil and examined for species of sarcocystis. sporocysts were observed in the mucosal scrapings of the small intestine from 3 opossums. five budgerigars, melopsittacus undulatus , were infected with sporocysts from each of these infected opossums and 5 budgerigars were used as controls. of the 15 sporocyst-treated budgerigars, 5 birds that received sporocysts from 1 of the infected opossums deve ... | 2012 | 22571294 |
| toxoplasma gondii antibodies in wild rodents and marsupials from the atlantic forest, state of são paulo, brazil. | toxoplasma gondii is a protozoan parasite that infects a large spectrum of warm-blooded animals, including humans. small rodents and marsupials play an important role in the epidemiology of t. gondii because they are sources of infection for domestic and feral cats. serum samples from 151 rodents and 48 marsupials, captured in the atlantic forest, são paulo state, southeastern brazil, were analyzed for the presence of t. gondii antibodies. antibodies detected by the modified agglutination test ( ... | 2015 | 26444068 |
| infection with trypanosoma cruzi tcii and tci in free-ranging population of lion tamarins (leontopithecus spp): an 11-year follow-up. | here, we present a review of the dataset resulting from the 11-years follow-up of trypanosoma cruzi infection in free-ranging populations of leontopithecus rosalia (golden lion tamarin) and leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in atlantic coastal rainforest. additionally, we present new data regarding t. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete t ... | 2015 | 25946156 |
| amblyomma yucumense n. sp. (acari: ixodidae), a parasite of wild mammals in southern brazil. | during 2013-2014, adult ticks were collected on the vegetation and subadult ticks were collected from small mammals [didelphis aurita wied-neuwied, sooretamys angouya (fischer), euryoryzomys russatus (wagner), akodon montensis thomas, oxymycterus judex thomas] in an atlantic rainforest reserve in southern brazil. analyses of the external morphology of the adult ticks revealed that they represent a new species, amblyomma yucumense n. sp. partial 16s rrna sequences generated from males, females, a ... | 2015 | 26336277 |
| the interaction of the antitoxin dm43 with a snake venom metalloproteinase analyzed by mass spectrometry and surface plasmon resonance. | dm43 is a circulating dimeric antitoxin isolated from didelphis aurita, a south american marsupial naturally immune to snake envenomation. this endogenous inhibitor binds non-covalently to jararhagin, the main hemorrhagic metalloproteinase from bothrops jararaca snake venom, and efficiently neutralizes its toxicity. the aim of this study was to apply mass spectrometry (ms) and surface plasmon resonance (spr) to improve the molecular characterization of this heterocomplex. the stoichiometry of th ... | 2012 | 22549991 |
| crotalid snake venom subproteomes unraveled by the antiophidic protein dm43. | snake venoms are mixtures of proteins and peptides with different biological activities, many of which are very toxic. several animals, including the opossum didelphis aurita, are resistant to snake venoms due to the presence of neutralizing factors in their blood. an antihemorrhagic protein named dm43 was isolated from opossum serum. it inhibits snake venom metalloproteinases through noncovalent complex formation with these enzymes. in this study, we have used dm43 and proteomic techniques to e ... | 2009 | 19267469 |
| using dna barcodes to identify road-killed animals in two atlantic forest nature reserves, brazil. | road mortality is the leading source of biodiversity loss in the world, especially due to fragmentation of natural habitats and loss of wildlife. the survey of the main species victims of roadkill is of fundamental importance for the better understanding of the problem, being necessary, for this, the correct species identification. the aim of this study was to verify if dna barcodes can be applied to identify road-killed samples that often cannot be determined morphologically. for this purpose, ... | 2015 | 26244644 |
| which factors determine spatial segregation in the south american opossums (didelphis aurita and d. albiventris)? an ecological niche modelling and geometric morphometrics approach. | didelphis albiventris and d. aurita are neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout south america, being primarily allopatric throughout their ranges. in the araucaria moist forest of southern brazil these species are sympatric and they might potentially compete having similar ecology. for this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might ... | 2016 | 27336371 |
| first evidence of gregarious denning in opossums (didelphimorphia, didelphidae), with notes on their social behaviour. | the didelphidae are considered solitary opossums with few social interactions, usually limited to mating-related or mother-pouch young interactions. anecdotal reports suggest that additional interactions occur, including den sharing by a few individuals, usually siblings. here, we report novel observations that indicate opossums are more social than previously thought. these include nest sharing by males and females of marmosa paraguayana, gracilinanus microtarsus and marmosops incanus prior to ... | 2015 | 26085500 |
| screening for target toxins of the antiophidic protein dm64 through a gel-based interactomics approach. | dm64 is a glycosylated protein with antivenom activity isolated from the serum of the opossum didelphis aurita. it binds non-covalently to myotoxins i (asp49) and ii (lys49) from bothrops asper venom and inhibits their myotoxic effect. in this study, an affinity column with immobilized dm64 as bait was used to fish potential target toxins. all ten isolated myotoxins tested were able to effectively bind to the dm64 column. to better access the specificity of the inhibitor, crude venoms from bothr ... | 2017 | 27216643 |
| detecting and modelling delayed density-dependence in abundance time series of a small mammal (didelphis aurita). | we study the population size time series of a neotropical small mammal with the intent of detecting and modelling population regulation processes generated by density-dependent factors and their possible delayed effects. the application of analysis tools based on principles of statistical generality are nowadays a common practice for describing these phenomena, but, in general, they are more capable of generating clear diagnosis rather than granting valuable modelling. for this reason, in our ap ... | 2016 | 26865413 |
| lumbosacral plexus in brazilian common opossum. | the opossum has been suggested as an animal model for biomedical studies due to its adaptability to captivity and number of births per year. despite many studies on morphology and experimental neurology using this opossum model, the literature does not offer details of the nerves of the lumbosacral plexus in this species. ten lumbosacral plexus were dissected to describe the peripheral innervations of the brazilian common opossum (didelphis aurita) and compare the results with eutheria clade spe ... | 2016 | 26711655 |
| edge effects and geometric constraints: a landscape-level empirical test. | edge effects are pervasive in landscapes yet their causal mechanisms are still poorly understood. traditionally, edge effects have been attributed to differences in habitat quality along the edge-interior gradient of habitat patches, under the assumption that no edge effects would occur if habitat quality was uniform. this assumption was questioned recently after the recognition that geometric constraints tend to reduce population abundances near the edges of habitat patches, the so-called geome ... | 2016 | 26250567 |
| coccidial dispersion across new world marsupials: klossiella tejerai scorza, torrealba & dagert, 1957 (apicomplexa: adeleorina) from the brazilian common opossum didelphis aurita (wied-neuwied) (mammalia: didelphimorphia). | klossiella tejerai scorza, torrealba & dagert, 1957 is a primitive coccidian parasite reported from the new world marsupials didelphis marsupialis (linnaeus) and marmosa demerarae (thomas). the current work describes k. tejerai from the brazilian common opossum didelphis aurita (wied-neuwied) in southeastern brazil, evidencing the coccidial dispersion across opossums of the same family. the sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed ... | 2014 | 25079818 |
| quantification of endocrine cells and ultrastructural study of insulin granules in the large intestine of opossum didelphis aurita (wied-neuwied, 1826). | this study aimed to investigate the distribution of argyrophil, argentaffin, and insulin-immunoreactive endocrine cells in the large intestine of opossums (didelphis aurita) and to describe the ultrastructure of the secretory granules of insulin-immunoreactive endocrine cells. fragments of the large intestine of 10 male specimens of d. aurita were collected, processed, and subjected to staining, immunohistochemistry, and transmission electron microscopy. the argyrophil, the argentaffin, and the ... | 2014 | 24359801 |
| new aspidoderidae species parasite of didelphis aurita (mammalia: didelphidae): a light and scanning electron microscopy approach. | nematodes of the family aspidoderidae (nematoda: heterakoidea) skrjabin and schikobalova, 1947, are widely distributed in the americas. the family aspidoderidae includes the subfamilies aspidoderinae skrjabin and schikobalova, 1947, and lauroiinae skrjabin and schikobalova, 1951. these two subfamilies are delineated by the presence or absence of cephalic cordons at the anterior region. the nematodes in the subfamily aspidoderinae, which includes the genus aspidoderarailliet and henry, 1912, are ... | 2014 | 24129095 |
| morphologic characterization and distribution of endocrine cells in the large intestine of the opossum didelphis aurita (wied-neuwied, 1826). | this study was designed to investigate the morphology and distribution of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in the large intestine of the opossum didelphis aurita. fragments of the large intestine of 10 male specimens of the opossum d. aurita were collected, processed, and submitted for histochemistry, immunohistochemistry, and scanning electron microscopy. the tunics of the large intestine of d. aurita presented morphological characteristics that have already ... | 2013 | 23810437 |
| endocrine cells and nerve ganglia of the small intestine of the opossum didelphis aurita wied-neuwied, 1826 (mammalia: didelphidae). | the nervous and endocrine systems jointly control intestinal movements, secretions of their glands and also participate of the processes of nutrient digestion and absorption. therefore, the central objective of this study was to verify the existence of a possible relationship between the number of nervous cells and ganglia of the submucosal and myenteric plexuses and the number of endocrine cells in the small intestine of adult d. aurita. the utilized staining techniques were grimelius, modified ... | 2012 | 22801379 |
| using mass spectrometry to explore the neglected glycan moieties of the antiophidic proteins dm43 and dm64. | the resistance of the opossum didelphis aurita to bothrops snake venoms is attributed to the opossum's antihemorrhagic (dm43) and antimyotoxic (dm64) acidic serum glycoproteins. the aim of this study was to characterize the n-glycosylation sites of these antiophidic proteins and to determine whether their glycans influence the biological activity measured by in vitro assays. our experimental pipeline included the sequential enzymatic digestion of the inhibitors with two different proteinases (tr ... | 2012 | 22744933 |
| analysis of the morphology and distribution of argentaffin, argyrophil and insulin-immunoreactive endocrine cells in the small intestine of the adult opossum didelphis aurita (wied-neuwied, 1826). | the aim of this study was to identify and quantify the argyrophil, argentaffin and insulin-immunoreactive cells (iic) in the small intestine of the opossum didelphis aurita. seven adult male specimens of opossums were investigated. the animals were captured, and their blood insulin levels were determined. after euthanasia, fragments of the small intestine were processed for light microscopy and transmission electron microscopy, and submitted to histochemistry and immunohistochemistry for identif ... | 2012 | 22608000 |
| topographic organization and corticocortical connections of the forepaw representation in areas s1 and sc of the opossum: evidence for a possible role of area sc in multimodal processing. | in small-brained mammals, such as opossums, the cortex is organized in fewer sensory and motor areas than in mammals endowed with larger cortical sheets. the presence of multimodal fields, involved in the integration of sensory inputs has not been clearly characterized in those mammals. in the present study, the corticocortical connections of the forepaw representation in the somatosensory caudal (sc) area of the didelphis aurita opossum was studied with injections of fluorescent anatomical trac ... | 2011 | 22069381 |
| cone visual pigments in two species of south american marsupials. | marsupials are largely confined to australasia and to central and south america. the visual pigments that underlie the photosensitivity of the retina have been examined in a number of species from the former group where evidence for trichromatic colour vision has been found, but none from the latter. in this paper, we report the cone opsin sequences from two nocturnal south american marsupial species, the gray short-tailed opossum, monodelphis domestica, and the big-eared opossum, didelphis auri ... | 2009 | 19133321 |
| architectonic subdivisions of the amygdalar complex of a primitive marsupial (didelphis aurita). | the architecture of the amygdaloid complex of a marsupial, the opossum didelphis aurita, was analyzed using classical stains like nissl staining and myelin (gallyas) staining, and enzyme histochemistry for acetylcholinesterase and nadph-diaphorase. most of the subdivisions of the amygdaloid complex described in eutherian mammals were identified in the opossum brain. nadph-diaphorase revealed reactivity in the neuropil of nearly all amygdaloid subdivisions with different intensities, allowing the ... | 2008 | 18395607 |
| [electroretinographic study of chromatic vision]. | to describe the electroretinogram of the south-american opossum (didelphis aurita) obtained by chromatic stimulus of specific wavelengths. the electroretinogram records voltage variations of retinal cells triggered by light stimulation. the electroretinogram represents the combination of electric activity of many different cells and varies according to retinal physiology and examination methods. | 2010 | 17273680 |
| calpain inhibitor 2 prevents axonal degeneration of opossum optic nerve fibers. | the ultrastructural change that characterizes the onset of wallerian degeneration is the disintegration of axoplasmic microtubules and neurofilaments, which are converted into an amorphous and granular material, followed by myelin breakdown. the mechanism underlying such processes is an increase in the amount of intracellular calcium, leading to activation of proteases called calpains. the aim of this study was to evaluate by quantitative ultrastructural analysis whether nerve fibers can be pres ... | 2004 | 15248297 |
| metabolic changes in the nucleus of the optic tract after monocular enucleation as revealed by cytochrome oxidase histochemistry. | the histochemistry for the mitochondrial enzyme cytochrome oxidase (co) was used to evaluate the levels of metabolic activity in neurons of the nucleus of the optic tract (not) and dorsal terminal nucleus (dtn) in the opossum (didelphis aurita). the observations were performed in four groups: normal juveniles (4 months old), monocularly enucleated juveniles analysed when adults, normal adults (8 to 18 months old) and monocularly enucleated adults. co labeled cells were observed to have a similar ... | 2001 | 11709628 |
| cortical and subcortical influences on the nucleus of the optic tract of the opossum. | in the present work we propose a new phylogenetic hypothesis for the role played by cortical and subcortical afferents to the nucleus of the optical tract, the main visual relay station of the horizontal optokinetic reflex in mammals. the hypothesis is supported by anatomical and physiological data obtained in the south american opossum (didelphis aurita) using the following experimental approaches: (i) single-unit recordings in the nucleus of the optic tract and simultaneous electrical stimulat ... | 2000 | 10682702 |
| ontogeny of cholinergic amacrine cells in the oppossum (didelphis aurita) retina. | immunocytochemistry for choline acetyltransferase (chat), the synthesizing enzyme for acetylcholine, was used to determine the onset and to follow the maturation of the cholinergic cells in the retina of a marsupial, the south american opossum (didelphis aurita). chat-immunoreactivity was first detected in amacrine cells in the ganglion cell layer by postnatal day 15 (p15) and in the inner nuclear layer by p35. much later, at p50 a second sub-population of chat-immunoreactive cell bodies was evi ... | 1999 | 10593615 |
| patterns of corticocortical, corticotectal, and commissural connections in the opossum visual cortex. | patterns of connections of the visual cortex of the south american opossum, didelphis aurita, were revealed by using neuronal tracers to identify and characterize visual specializations of the peristriate cortex (ps). the visuotopy of corticotectal connections of the anterolateral portion of ps (psal) is symmetrical to that of the striate cortex (st or primary visual area [v1]). three consecutive bands of commissural connections coincide, respectively, with the st-ps border, the limit between th ... | 2000 | 10581468 |
| a comparative study of lymph node mast cell populations in five marsupial species. | in order to determine whether different subpopulations of mast cells exist, mast cells of mandibular and axillary lymph nodes from five species (didelphis aurita, metachirus nudicaudatus, philander opossum, marmosops incanus and gracilinanus agilis) of south american marsupials were studied. our results showed that mast cells present in the connective tissue of the capsule and septa (ctmc) were similar to those described for eutherian mammals. however, a population of mast cells that was present ... | 1999 | 10481303 |
| morphologic and histochemical study on perianal glands of the opossum (didelphis aurita). the role of mast cells on the secretion of mucopolysaccharides. | | 1967 | 5587520 |
| identification of opossums didelphis aurita (wied-neuweid, 1826) as a definitive host of sarcocystis falcatula-like sporocysts. | this study was conducted to identify the sarcocystis species that infect the opossum didelphis aurita in order to determine which sporocysts they are excreating in to the environment and help determine the role of d. aurita in the epidemiology of sarcocystis. sporocysts were obtained from intestinal tracts of 8 of 13 d. aurita trapped in rio de janeiro state, brazil, and were orally inoculated into melopsittacus undulatus and balb/c nude mus musculus. portions of organs and muscles were processe ... | 2018 | 29192336 |
| atlantic small-mammal: a dataset of communities of rodents and marsupials of the atlantic forests of south america. | the contribution of small mammal ecology to the understanding of macroecological patterns of biodiversity, population dynamics, and community assembly has been hindered by the absence of large datasets of small mammal communities from tropical regions. here we compile the largest dataset of inventories of small mammal communities for the neotropical region. the dataset reviews small mammal communities from the atlantic forest of south america, one of the regions with the highest diversity of sma ... | 2017 | 28500789 |
| trypanosoma janseni n. sp. (trypanosomatida: trypanosomatidae) isolated from didelphis aurita (mammalia: didelphidae) in the atlantic rainforest of rio de janeiro, brazil: integrative taxonomy and phylogeography within the trypanosoma cruzi clade. | didelphis spp. are a south american marsupial species that are among the most ancient hosts for the trypanosoma spp. | 2018 | 29211107 |
| heterologous expression of the antimyotoxic protein dm64 in pichia pastoris. | snakebite envenomation is a neglected condition that constitutes a public health problem in tropical and subtropical countries, including brazil. interestingly, some animals are resistant to snake envenomation due to the presence of inhibitory glycoproteins in their serum that target toxic venom components. dm64 is an acidic glycoprotein isolated from didelphis aurita (opossum) serum that has been characterized as an inhibitor of the myotoxicity induced by bothropic toxins bearing phospholipase ... | 2017 | 28759578 |
| diet overlap and spatial segregation between two neotropical marsupials revealed by multiple analytical approaches. | species co-existence depends on how organisms utilize their environment and resources. when two sympatric species are similar in some ecological requirements, their coexistence may arise from differences in resource use over time and/or space. interactions among coexisting marsupials remain poorly understood, especially in the neotropics. here we combine spatial niche measurements, individual-resource networks, and isotopic niche approaches, to investigate the ecological strategies used by the n ... | 2017 | 28704561 |
| resistance of south american opossums to vwf-binding venom c-type lectins. | opossums in the clade didelphini are well known to be resistant to snake venom due to endogenous circulating inhibitors which target metalloproteinases and phospholipases. however, the mechanisms through which these opossums cope with a variety of other damaging venom proteins are unknown. a protein involved in blood clotting (von willebrand factor) has been found to have undergone rapid adaptive evolution in venom-resistant opossums. this protein is a known target for a subset of snake venom c- ... | 2020 | 32135198 |
| parotid salivary gland basal cell adenocarcinoma in a big-eared opossum (didelphis aurita). | the opossum (family didelphidae) is a marsupial endemic to the americas. apart from the south american short-tailed opossum (monodelphis domestica) and the virginia opossum (didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. among these, the big-eared opossum (didelphis aurita) is found in argentina, brazil and paraguay. natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic ... | 2018 | 29599001 |
| mapping brazilian spotted fever: linking etiological agent, vectors, and hosts. | brazilian spotted fever (bsf) is a highly lethal disease in southeastern brazil. bsf is caused by the bacterium rickettsia rickettsii and is transmitted by the bites of the tick of the genus amblyomma. the spatial distribution of bsf risk areas is not well known in the country given the complexity of the transmission cycle. this study used the ecological niche modeling (enm) approach to anticipate the potential distribution of the etiological agent (rickettsia rickettsii), vectors (amblyomma scu ... | 2020 | 32315604 |
| knowledge, practice and perception of human-marsupial interactions in health promotion. | approximately 60% of emerging pathogens originate from wild animals, with mammals being the main hosts. among didelphis, which are restricted to the americas, the species didelphis aurita and didelphis albiventris are particularly widely distributed throughout brazil, where they act as hosts for several pathogens transmissible to humans. the reduction of their natural habitat has resulted in the adaptation of these species to human environments. animals hunting, due to food necessity or cultural ... | 2019 | 32045379 |
| ticks, fleas and endosymbionts in the ectoparasite fauna of the black-eared opossum dipelphis aurita in brazil. | ticks and fleas are essential vectors of pathogens that affect humans and animals, and among their hosts, synanthropic animals such as the black-eared opossum, didelphis aurita, play a role in public health due to their ability to move between urban centers and forested areas in brazil. this study aimed to assess the ectoparasite fauna of d. aurita, as well as the presence of pathogens and endosymbionts in ticks and fleas. opossums (n = 58) captured in tomahawk livetraps were examined for ectopa ... | 2020 | 31927646 |
| detection of a putative novel genotype of ehrlichia sp. from opossums (didelphis aurita) from brazil. | erlichiosis affects humans and animals worldwide. its distribution and prevalence depends on the presence of tick vectors and hosts in one geographic area. the aim of the present study was to investigate the occurrence of ehrlichia spp. and anaplasma spp. in opossums (didelphis sp.) from the state of rio de janeiro, southeast brazil. blood samples from 37 animals were tested for these two pathogens using molecular methods. one animal (2.7%) was positive for ehrlichia sp. by 16s rrna-based nested ... | 2019 | 30427523 |
| a novel marsupial hepatitis a virus corroborates complex evolutionary patterns shaping the genus hepatovirus. | the discovery of highly diverse nonprimate hepatoviruses illuminated the evolutionary origins of hepatitis a virus (hav) ancestors in mammals other than primates. marsupials are ancient mammals that diverged from other eutheria during the jurassic. viruses from marsupials may thus provide important insight into virus evolution. to investigate hepatovirus macroevolutionary patterns, we sampled 112 opossums in northeastern brazil. a novel marsupial hav (mhav) in the brazilian common opossum (didel ... | 2018 | 29695421 |
| linking human and ecological components to understand human-wildlife conflicts across landscapes and species. | human-wildlife conflicts (hwc) are complex conservation challenges that impair both wildlife populations and human livelihood. research on hwc, however, has traditionally approached ecological and human components separately, hampering a broader understanding of connections between ecological drivers and human dimensions of conflicts. we developed a model that integrates ecological and human components of hwc to investigate how the amount of remaining native forest (forest cover, a key ecologica ... | 2020 | 32406127 |
| factors associated with hard tick (acari: ixodidae) parasitism in medium-sized mammals in the atlantic rainforest region of argentina. | associations with environmental and host parameters were assessed to describe tick parasitism patterns in two medium-sized mammals of the atlantic rainforest region of argentina. ticks found on 93 specimens of nasua nasua and 26 specimens of didelphis aurita captured at six sites in the iguazú national park were collected. generalized linear models were constructed to explain the presence and abundance of ticks and the most appropriate ones were selected after stepwise simplification. the season ... | 2018 | 30006201 |
| ticks parasitizing wild mammals in atlantic forest areas in the state of rio de janeiro, brazil. | mammals captured in the serra dos órgãos national park (parnaso) and the pedra branca state park (pbsp) between 2012 and 2015 were examined for the presence of ticks. in total, 140 mammals were examined, and 34 specimens were found to be parasitized by ticks. didelphis aurita, akodon montensis and oligoryzomys nigripes were the species most parasitized. from these specimens, 146 ticks were collected, including 10 larvae. the ticks belonged to eight species: one in the genus ixodes and seven in t ... | 2019 | 29846459 |
| eimeria spp. (apicomplexa: eimeriidae) of marsupials (mammalia: didelphimorphia) in southern bahia, brazil. | the occurrence of eimeria schneider, 1875 in mammals of the order didelphimorphia indicates the infection-predisposition of these animals, which in turn is mainly determined for their eating habits. the objective of this work was to evaluate the parasitism of eimeria spp. in marsupials of the atlantic forest of the southern region of bahia. fecal samples were collected from marsupials captured in the regions of ilhéus, una, belmonte and mascote, with traps of the sherman model (23 × 8 × 9 cm), t ... | 2019 | 30427519 |
| gastrointestinal parasites in the opossum didelphis aurita: are they a potential threat to human health? | currently, a great proportion of the emerging infectious human diseases are zoonotic, with most of the pathogens originated from wildlife. in this sense, synanthropic animals such as marsupials play important role in the dissemination of pathogens due to their proximity to human dwellings. these hosts are affected by many gastrointestinal parasites, including species with zoonotic potential. the aim of this study was to assess the diversity of gastrointestinal parasites infecting the black-eared ... | 2020 | 32508410 |
| high prevalence of ancylostoma caninum infection in black-eared opossums (didelphis aurita) in an urban environment. | marsupials of the genus didelphis, such as black-eared opossums (didelphis aurita), are common synanthropic animals in urban areas of brazil. these marsupials are frequently parasitized by numerous helminth species, including ancylostomatid nematodes. this study aimed to report the occurrence of ancylostoma caninum in black-eared opossums captured in an urban environment of southeastern brazil and discuss the potential impact of these findings for public health. from january to june 2019, we col ... | 2020 | 32435896 |
| anatomical characterization of the kidneys of didelphis aurita (didelphimorphia: didelphidae). | didelphis aurita is a marsupial with wide distribution in the south american continent and highly adapted to urban centers. the objective of this study was to describe the measurements and skeletopy of the kidneys and renal vascularization of this species. with this aim, 29 cadavers (14 males and 15 females) of d. aurita collected on highways were analyzed. the rostrum-sacral length of specimens, kidney measurements (length, width and thickness) and the length of the renal vessels were measured ... | 2020 | 32020581 |
| a case of polymelia associated with syndactyly in didelphis aurita (wied-neuwied, 1826). | in january 2018, a young male of didelphis aurita (wied-neuwied, 1826), the brazilian common opossum, was admitted for veterinary evaluation at the recovery clinic of wild animals of estácio de sá university, cras, in rio de janeiro, brazil, due to the presence of a partially duplicated right hind limb. after x-ray evaluation, polymelia associated with syndactyly was diagnosed. the images revealed the following alterations on the right limb: single femur with increased diameter, two tibiae, two ... | 2020 | 31644652 |
| metacommunity structure of the helminths of the black-eared opossum didelphis aurita in peri-urban, sylvatic and rural environments in south-eastern brazil. | among the brazilian marsupials, the species of the genus didelphis are the most parasitized by helminths. this study aimed to describe the species composition and to analyse the helminth communities of the atlantic forest common opossum didelphis aurita at infracommunity and component community levels using the elements of metacommunity structure analysis, considering peri-urban, sylvatic and rural environments in the state of rio de janeiro, brazil. seventy-three specimens of d. aurita were cap ... | 2019 | 30220264 |