Publications

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pcr-based diagnosis for detection of leishmania in skin and blood of rodents from an endemic area of cutaneous and visceral leishmaniasis in brazil.the technique of polymerase chain reaction (pcr) associated to hybridization was used to screen 123 samples collected from wild and synanthropic rodents captured in a cutaneous and visceral leishmaniasis endemic area in the state of minas gerais, brazil. the detection of leishmania spp in naturally infected rodents is of fundamental importance for incriminating them as possible reservoir hosts of the diseases in minas gerais. a total of 62 specimens belonging to wild (thrichomys apereoides, oryz ...200515845276
development of the inverted visceral yolk sac in three species of caviids (rodentia, caviomorpha, caviidae).guinea pig related rodents possess numerous derived placental characters. we attempt to identify diversity within the visceral yolk sac and its association with the chorioallantoic placenta in three species of caviids, two of them possessing a capsule formed by the decidua that covers the chorioallantoic placenta. the results verify that in early pregnancy all three species have an inverted yolk sac placenta. in advanced pregnancy the species differ: galea spixii, as representative without a cap ...200818586321
chorioallantoic placentation in galea spixii (rodentia, caviomorpha, caviidae).placentas of guinea pig-related rodents are appropriate animal models for human placentation because of their striking similarities to those of humans. to optimize the pool of potential models in this context, it is essential to identify the occurrence of characters in close relatives.200818771596
experimental infection parameters in galea spixii (rodentia: caviidae) with leishmania infantum chagasi.in order to better understand the epidemiological transmission network of leishmaniasis, an endemic disease in northeast brazil, we investigated the susceptibility of spix yellow-toothed cavies (galea spixii) to the leishmania infantum chagasi parasite. nine cavies were experimentally infected, separated into three groups and monitored at 30, 90 and 180 days, respectively. amastigotes were identified in the spleen slides of two cavies killed 180 days after infection. antibodies against the l. i. ...200818949323
development of yolk sac inversion in galea spixii and cavia porcellus (rodentia, caviidae).caviomorph development includes an inverted yolk sac. since principle processes are not understood, we investigated its differentiation in galea and re-examined material from the guinea pig. galea showed the typical caviomorph conditions in blastocyst development and the nature of the definitive yolk sac, formed of the visceral layer that became villous, proliferative, vascularized and attached to the uterus and placenta. in contrast to what was known before, in both species parts of the parieta ...201222809674
development of spermatogenesis in captive-bred spix's yellow-toothed cavy (galea spixii).the aim of this study was to evaluate the phases of sexual development and spermatogenesis of spix's yellow-toothed cavy (galea spixii) based on analyses of the structural components of the testes. the testes of animals from 0 to 150 days of age were collected by orchiectomy, weighed, and processed for analysis by light microscopy. at 45 days of age, spermatozoa were seen in the tubular lumen. spermatogenesis was not established in animals from 45 to 150 days of age. the stages of sexual develop ...201222781939
scg postnatal remodelling--hypertrophy and neuron number stability--in spix's yellow-toothed cavies (galea spixii).whilst a fall in neuron numbers seems a common pattern during postnatal development, several authors have nonetheless reported an increase in neuron number, which may be associated with any one of a number of possible processes encapsulating either neurogenesis or late maturation and incomplete differentiation. recent publications have thus added further fuel to the notion that a postnatal neurogenesis may indeed exist in sympathetic ganglia. in the light of these uncertainties surrounding the e ...201222212604
ultrastructure of spermatogenesis in spix's yellow-toothed cavy (galea spixii).this was a pioneer study of the spermatogenic process from the onset of puberty in spix's yellow-toothed cavies (syc, galea spixii) bred in captivity. the study aimed to characterize fine structure of spermatogenesis. twelve testes from pubertal and post-pubertal syc males were studied using transmission electron microscopy. spermatogenesis can be divided into three phases: proliferation, meiosis, and spermiogenesis. in proliferation phase, three types of spermatogonia were identified and charac ...201424101585
domestic, peridomestic and wild hosts in the transmission of trypanosoma cruzi in the caatinga area colonised by triatoma brasiliensis.the role played by different mammal species in the maintenance of trypanosoma cruzi is not constant and varies in time and place. this study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of t. cruzi in tauá, state of ceará, caatinga area, brazil, with an emphasis on those environments colonised by triatoma brasiliensis. direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and out ...201425410992
domestic, peridomestic and wild hosts in the transmission of trypanosoma cruzi in the caatinga area colonised by triatoma brasiliensis.the role played by different mammal species in the maintenance of trypanosoma cruzi is not constant and varies in time and place. this study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of t. cruzi in tauá, state of ceará, caatinga area, brazil, with an emphasis on those environments colonised by triatoma brasiliensis. direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and out ...201425165976
trypanosoma cruzi iii causing the indeterminate form of chagas disease in a semi-arid region of brazil.trypanosoma cruzi is subdivided into six discrete typing units (dtus), tci-tcvi. the precise identification of each can contribute to tracking wild dtus that invade the domiciliary environment.201526327123
molecular identification of food sources in triatomines in the brazilian northeast: roles of goats and rodents in chagas disease epidemiology.we used the gut contents of triatomines collected from rural areas of ceará state, northeastern brazil, to identify their putative hosts via vertebrate cytb gene sequencing. successful direct sequencing was obtained for 48% of insects, comprising 50 triatoma brasiliensis, 7 triatoma pseudomaculata, and 1 rhodnius nasutus. basic local alignment search tool (blast) procedure revealed that domestic animals, such as chickens (gallus gallus) and goats (capra hircus), are the main food source, includi ...201526350453
characterisation and cryopreservation of the ovarian preantral follicle population from spix.the aim of the present study was to characterise the ovarian preantral follicle (pf) population and to establish a solid surface vitrification (ssv) process using dimethyl sulfoxide (dmso) as a cryoprotectant for preservation of ovarian tissue from yellow-toothed cavies (galea spixii). ovaries were fixed for pf population analysis or were subjected to the ssv process. the mean (± s.e.m.) pf population per ovarian pair was estimated to be 416.0 ± 342.8. there were 140.0 ± 56.0 (63.4%) and 125.0 ± ...201526446279
the morphology of the pineal gland of the yellow-toothed cavy (galea spixii wagler, 1831) and red-rumped agouti (dasyprocta leporina linnaeus, 1758).the pineal gland is an endocrine gland found in all mammals. this article describes the morphology of this important gland in two species of caviideae, namely the yellow-toothed cavy and the red-rumped agouti. ten adult animals of the two species used in current analysis were retrieved from the center for the multiplication of wild animals (cemas/ufersa) and euthanized. the glands were removed and photographed in situ and ex situ. they were fixed in a paraformaldehyde solution 4% or glutaraldehy ...201526096491
adrenal glands of spix's yellow-toothed cavy (galea spixii, wagler, 1831): morphological and morphometric aspects.considering the physiological importance and need of greater morphophysiological knowledge of adrenal glands, the aims of present study were compare the morphometric data between left and right adrenal of male and female; perform a histological, scanning and transmission electron microscopy study showing tissue constitution of glands; finally, in order to define the presence and correct site of the cytochrome p450c17 expression in adrenal glands, immunohistochemical study of this enzyme was perf ...201627143060
development and morphological changes in the vaginal closure membrane throughout gestation in galea spixii (rodentia: caviidae).present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (vcm) throughout pregnancy in galea spixii. the results showed that at 20 days of gestation (dg), the vcm occludes completely the external vaginal ostium. microscopically, the vcm presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 dg and a ...201626873391
molecular individual-based approach on triatoma brasiliensis: inferences on triatomine foci, trypanosoma cruzi natural infection prevalence, parasite diversity and feeding sources.we used an individual-based molecular multisource approach to assess the epidemiological importance of triatoma brasiliensis collected in distinct sites and ecotopes in rio grande do norte state, brazil. in the semi-arid zones of brazil, this blood sucking bug is the most important vector of trypanosoma cruzi--the parasite that causes chagas disease. first, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). second, we ...201626891047
comparison of different extenders on the recovery and longevity of epididymal sperm from spix's yellow-toothed cavies (galea spixii wagler, 1831).the aim of this study was to evaluate the performance of cavy (galea spixii) epididymal sperm following addition to tes or tris extenders and using a thermal resistance test (trt), as well as fluorescence analysis as a complementary method to predict the viability of these gametes. nine testicle-epididymis complexes were used for sperm collection using a flotation method. epididymis tails were sliced and one was immersed in 3 ml of tris buffer, and the other in 3 ml of tes, for 5 min. after sper ...201728245889
follicular development and morphological changes in the vaginal epithelium during the estrous cycle of galea spixii.the current study aimed to determine if characteristics observed in vaginal cytology during the estrous cycle of female syt cavies corresponded with proliferation of the vaginal epithelium, characterized by proliferating cell nuclear antigen (pcna) immunolocalization, and with follicular development at different phases of the estrous cycle. after determining estrous cycle phases by vaginal cytology, females were euthanized at metestrus, diestrus, proestrus, and estrus. histological study of the ...201727717109
steroidogenesis during postnatal testicular development of galea spixii.the androgen/estrogen balance is essential for normal sexual development and reproduction in mammals. studies performed herein investigated the potential for estrogen synthesis in cells of the testes of a hystricomorph rodent, galea spixii the study characterized the expression of the key enzymes responsible for estrogen and androgen synthesis, cytochromes p450 aromatase (p450arom), 17α-hydroxylase/17,20-lyase (p450c17) respectively, as well as the redox partner nadph cytochrome p450 oxido-reduc ...201728982933
characterisation and cryopreservation of the ovarian preantral follicle population from spix's yellow-toothed cavies (galea spixii wagler, 1831).the aim of the present study was to characterise the ovarian preantral follicle (pf) population and to establish a solid surface vitrification (ssv) process using dimethyl sulfoxide (dmso) as a cryoprotectant for preservation of ovarian tissue from yellow-toothed cavies (galea spixii). ovaries were fixed for pf population analysis or were subjected to the ssv process. the mean (± s.e.m.) pf population per ovarian pair was estimated to be 416.0±342.8. there were 140.0±56.0 (63.4%) and 125.0±58.0 ...201728442066
immunolocalization of steroidogenic enzymes in the vaginal mucous of galea spixii during the estrous cycle.the synthesis of sex steroids is controlled by several enzymes such as17α-hydroxylase cytochrome p450 (p450c17) catalyzing androgen synthesis and aromatase cytochrome p450 (p450arom) catalyzing estrogen synthesis, both of which must complex with the redox partner nadph-cytochrome p450 oxidoreductase (cpr) for activity. previous studies have identified expression of steroidogenic enzymes in vaginal tissue, suggesting local sex steroid synthesis. the current studies investigate p450c17, p450aromat ...201728438170
detection of anti-toxoplasma gondii antibodies in small wild mammals from preserved and non-preserved areas in the caatinga biome, a semi-arid region of northeast brazil.this study was conducted to determine the seroprevalence of anti-toxoplasma gondii antibodies in 152 free-living small wild mammals from distinct regions in the caatinga biome, a semi-arid region in the northeast of brazil: the national park of serra das confusões (npsc), which is a preserved area in the state of piauí, and the municipalities of petrolina and lagoa grande, two non-preserved areas in the state of pernambuco. using the modified agglutination test (mat), we found that 5.3% (4/75) a ...201831014742
trypanosoma cruzi in triatomines and wild mammals in the national park of serra das confusões, northeastern brazil.the national park of serra das confusões (npsc) is a protected area of natural landscape located in southern piauí, brazil, and it is considered as one of the largest and most important protected areas in the caatinga biome.201830133626
development of urogenital system in the spix cavy: a model for studies on sexual differentiation.this study documented, for the first time, the morphological patterns of differentiation of male and female genital organs of spix cavy (galea spixii) using histological and ultrastructural analyses, with immuno-localization of steroidogenic enzymes, cytochromes p450 aromatase (p450arom) and 17α-hydroxylase/17, 20-lyase (p450c17), involved in the synthesis of estrogens and androgens respectively throughout fetal sexual development. undifferentiated gonads of spix cavy develop into ovaries in fem ...201829684807
epididymal sperm from spix's yellow-toothed cavies sperm successfully cryopreserved in tris extender with 6% glycerol and 20% egg yolk.as a non-threatened hystricognath rodent species, spix's yellow-toothed cavies can be used as a model for the development of assisted reproductive techniques for the conservation of closely related species. the objective was to establish a functional protocol for cryopreservation of epididymal sperm from these cavies. twelve sexually mature males, ∼2 y old and weighing ∼300 g, were euthanized. sperm were recovered by retrograde flushing of the vas deferens and cauda epididymis with tris extender ...201829463464
dynamics of food sources, ecotypic distribution and trypanosoma cruzi infection in triatoma brasiliensis from the northeast of brazil.innovative approaches used to combat chagas disease transmission tend to combine a set of comprehensive efforts to understand the ecology of local vectors. in this work we identified molecularly the blood meal of 181 triatoma brasiliensis, distributed in 18 populations (8 sylvatic and 10 peridomestic), which were collected across a range of 240 km (east-west) and 95 km (north-south) in the semi-arid region of northeastern, brazil. we used the vertebrate mitochondrial gene (cytochrome b) sequenci ...202032986738
how does spix's yellow-toothed cavy (galea spixii wagler, 1831) face the thermal challenges of the brazilian tropical dry forest?the aim of this work was to investigate the thermal biology of the spix's yellow-toothed cavy (galea spixii) from the hot and dry environment of the brazilian caatinga by infrared thermography and biophysical equations. we monitored the rectal temperature, as well as the non-evaporative (radiative and convective pathways) and evaporative heat exchanges of males and females. the mean rectal temperature of females and males was 37.58 ± 0.02 and 37.47 ± 0.02 °c, respectively. we identified thermal ...202032126000
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