Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 71
Filtrar
1.
Sci Rep ; 13(1): 16417, 2023 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-37775538

RESUMO

Polarimetry is an optical characterization technique capable of analyzing the polarization state of light reflected by materials and biological samples. In this study, we investigate the potential of Müller matrix polarimetry (MMP) to analyze fresh pancreatic tissue samples. Due to its highly heterogeneous appearance, pancreatic tissue type differentiation is a complex task. Furthermore, its challenging location in the body makes creating direct imaging difficult. However, accurate and reliable methods for diagnosing pancreatic diseases are critical for improving patient outcomes. To this end, we measured the Müller matrices of ex-vivo unfixed human pancreatic tissue and leverage the feature-learning capabilities of a machine-learning model to derive an optimized data representation that minimizes normal-abnormal classification error. We show experimentally that our approach accurately differentiates between normal and abnormal pancreatic tissue. This is, to our knowledge, the first study to use ex-vivo unfixed human pancreatic tissue combined with feature-learning from raw Müller matrix readings for this purpose.


Assuntos
Diagnóstico por Imagem , Humanos , Diagnóstico por Imagem/métodos , Análise Espectral
2.
Syst Biol ; 72(6): 1247-1261, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-37561391

RESUMO

Convergent evolution is defined as the independent evolution of similar phenotypes in different lineages. Its existence underscores the importance of external selection pressures in evolutionary history, revealing how functionally similar adaptations can evolve in response to persistent ecological challenges through a diversity of evolutionary routes. However, many examples of convergence, particularly among closely related species, involve parallel changes in the same genes or developmental pathways, raising the possibility that homology at deeper mechanistic levels is an important facilitator of phenotypic convergence. Using the genus Ranitomeya, a young, color-diverse radiation of Neotropical poison frogs, we set out to 1) provide a phylogenetic framework for this group, 2) leverage this framework to determine if color phenotypes are convergent, and 3) to characterize the underlying coloration mechanisms to test whether color convergence occurred through the same or different physical mechanisms. We generated a phylogeny for Ranitomeya using ultraconserved elements and investigated the physical mechanisms underlying bright coloration, focusing on skin pigments. Using phylogenetic comparative methods, we identified several instances of color convergence, involving several gains and losses of carotenoid and pterin pigments. We also found a compelling example of nonparallel convergence, where, in one lineage, red coloration evolved through the red pterin pigment drosopterin, and in another lineage through red ketocarotenoids. Additionally, in another lineage, "reddish" coloration evolved predominantly through structural color mechanisms. Our study demonstrates that, even within a radiation of closely related species, convergent evolution can occur through both parallel and nonparallel mechanisms, challenging the assumption that similar phenotypes among close relatives evolve through the same mechanisms.


Assuntos
Rãs Venenosas , Venenos , Animais , Filogenia , Pigmentação/genética , Anuros , Pterinas/metabolismo , Evolução Biológica
3.
J Fungi (Basel) ; 9(5)2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37233251

RESUMO

Bellucia imperialis is one of the most abundant pioneer tree species in anthropized areas of the Central Amazon, and has ecological importance for the environmental resilience of phosphorus (P)-depleted areas. Thus, we investigated whether B. imperialis depends on symbiosis with arbuscular mycorrhizal fungi (AMF) to grow and establish under the edaphic stresses of low nutrient content and low surface moisture retention capacity of the substrate. We tried three AMF inoculation treatments: (1) CON-no mycorrhizae; (2) MIX-with AMF from pure collection cultures, and (3) NAT-with native AMF, combined with five doses of P via a nutrient solution. All CON treatment seedlings died without AMF, showing the high mycorrhizal dependence of B. imperialis. Increasing P doses significantly decreased the leaf area and shoot and root biomass growth for both the NAT and MIX treatments. Increasing P doses did not affect spore number or mycorrhizal colonization, but decreased the diversity of AMF communities. Some species of the AMF community showed plasticity, enabling them to withstand shortages of and excess P. B. imperialis was shown to be sensitive to excess P, promiscuous, dependent on AMF, and tolerant of scarce nutritional resources, highlighting the need to inoculate seedlings to reforest impacted areas.

4.
Transl Anim Sci ; 6(3): txac095, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36158170

RESUMO

The shortest interval between calving and initiation of fixed-time artificial insemination (FTAI) protocols recommended in Brazilian cow-calf systems is 30 d, based on research that characterized uterine involution and incidence of uterine disorders in Bos taurus females. Prevalence of uterine disorders such as subclinical endometritis is limited in Nelore (B. indicus) cows as early as 28 d after calving. We hypothesized that Nelore cows can receive an FTAI protocol as early as 20 d postpartum (DPP) and still experience satisfactory reproductive results. This study evaluated pregnancy rates in 5,258 Nelore cows (n = 1,703 primiparous and 3,555 multiparous) according to DPP at the initiation of the FTAI protocol. Cow body condition score (BCS) was recorded at FTAI, and pregnancy diagnosis was performed ~30 d after FTAI. Cows were ranked within parity by DPP at the initiation of the FTAI protocol and classified according to 5-d intervals (e.g., ≤15 DPP, 16 to 20 DPP, 21 to 26 DPP, until cows with ≥76 DPP). Data were analyzed within parity, using cow as experimental unit and orthogonal polynomial contrasts (linear, quadratic, or cubic) generated using the mean DPP of each DPP class. In both parities, cow BCS at FTAI decreased linearly (P ≤ 0.01) with the advance of DPP (e.g., 4.79, 4.00, and 3.73 in primiparous, and 4.95, 3.70, and 3.23 in multiparous cows classified as ≤15 DPP, 36 to 40 DPP, ≥76 DPP, respectively). The pregnancy rate to FTAI was affected quadratically (P < 0.01) by DPP for both parities. In primiparous cows, the pregnancy rate increased until 36 to 40 DPP (60%), remained near this level until 51 to 60 DPP, and then decreased with the advance of DPP, whereas cows classified as 21 to 25 DPP expressed satisfactory results (41.5%). In multiparous cows, the pregnancy rate increased until 46 to 50 DPP (70.8%), remained near this level until 56 to 60 DPP, and then decreased with the advance of DPP, whereas cows classified as 21 to 25 DPP also expressed satisfactory results (63.6%). Collectively, primiparous and multiparous Nelore cows evaluated herein experienced optimal pregnancy rates when the FTAI protocol was initiated within 30 to 60 DPP, although reasonable outcomes were observed when the FTAI protocol was initiated as early as 21 DPP. Hence, the interval between calving and initiation of the FTAI protocol can be shortened by 10 d in Nelore females and still yield acceptable pregnancy rates, which can be of great value to cows that calve immediately prior to or during the annual breeding season.

5.
An Acad Bras Cienc ; 94(1): e20191254, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35043846

RESUMO

Atractus badius has a long and controversial nomenclatural history due to both its antiquity and the brevity of its original description. This species was described based on two syntypes from Java. Later, a lectotype was designated and the distribution range restricted to the Guiana Shield. Although this species has been repeatedly recorded throughout Amazonia and the Andes, these records have been erroneously assigned to A. badius because of a considerable level of confusion in the literature. We found 13 additional specimens of this poorly known snake, expanding our knowledge on its morphological variability, phylogenetic relationships and distribution. In this paper, we report new localities and data on meristic, morphometric, coloration, scales micro-ornamentation, osteology and hemipenial morphology to A. badius. We also determine the phylogenetic position of A. badius as nested in a composite Guiana Shield clade. In addition, we discuss recent advances on the systematics of Atractus and comment on some 'new arrangements' with respect to previously recognized species groups and available morphological evidence. Finally, we highlight the importance of accurate voucher identification before promoting taxonomic changes or implementing nomenclatural acts derived from new phylogenetic hypotheses, and notably propose the synonymy of the recently described A. pyroni with A. roulei.


Assuntos
Genômica , Serpentes , Animais , Brasil , Osteologia , Filogenia , Serpentes/genética
6.
Arq. Inst. Biol. (Online) ; 89: e00112022, 2022. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1416887

RESUMO

The presence of capybaras (Hydrochoerus hydrochaeris) in urban and periurban areas has caused increased numbers of cases of Brazilian spotted fever. With the aim of investigating the presence of the parasitoid Ixodiphagus hookeri in Amblyomma sculptum ticks in the municipality of Salto, state of São Paulo, samples were collected monthly from 14 sites. Thirty samples were placed in containers for observation of the emergence of microhymenopterans and 88 samples were subjected to molecular testing to identify the presence of I. hookeri DNA. Neither dissections nor observation of emergence indicated any presence of I. hookeri larvae in ticks. Samples subjected to polymerase chain reaction (PCR) amplification of the mCOX I region of I. hookeri did not reveal its presence, although fragments corresponding to mRNA 16S of Amblyomma sculptum ticks were amplified in all samples tested.


Assuntos
Parasitos , Amblyomma/parasitologia , Himenópteros , Reação em Cadeia da Polimerase , Técnicas de Diagnóstico Molecular
7.
Int J Microbiol ; 2021: 9364231, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34824584

RESUMO

Determination of the susceptibility profile of isolates of Candida from blood culture bottles is extremely important for correctly guiding patient pharmacotherapy. The aim of this study was to compare the results of analysis of Candida isolated directly from blood culture bottles by the VITEK MS MALDI-TOF identification system and the fluconazole disk diffusion assay with those of standard identification methods. Testing directly from the bottle allowed results 24 to 48 hours quicker than the standard method. There was a categorical agreement of 51.64% (47 of 91 samples) between the results of analysis directly from the bottle and analysis by the standard method. Regarding species identification, there was 96.15% agreement for Candida parapsilosis (25 of 26 samples). Categorical agreement between the rapid and standard disk diffusion methods was 95%, and the agreement between the rapid disk diffusion method and the broth microdilution method was 97%. Only minor errors in the rapid method were observed: 3 (5%) in the standard disk diffusion method and 2 (3%) in the broth microdilution method. Our study concluded that the rapid disk diffusion method for fluconazole is a fast, easy, reproducible, and consistent method. Its timely implementation for testing antifungal agents in the clinical microbiology laboratory can help reduce profile release times, thus helping to determine the most appropriate antifungal treatment.

8.
Animals (Basel) ; 11(11)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34827923

RESUMO

Trypanosoma vivax outbreaks have been reported with increasing frequency worldwide, causing significant economic losses in livestock. Though several studies have suggested that cytokine responses may influence infection caused by Trypanosoma sp., their exact role remains unclear and may vary according to the animal species and parasite strain. The present study aimed to evaluate cytokine expression of peripheral blood cells from three Girolando dairy cows experimentally infected with T. vivax. For this purpose, blood samples were collected prior to the inoculation on the day of inoculation (D0), the day after inoculation (D1), and then every seven days up to 119 days after infection (DAI). Each animal presented a unique pattern of cytokine expression. While a tendency of a Th1 cytokine response was observed during the patent phase (presence of circulating parasites), an increase of Th2 cytokine expression was found at the beginning of the sub-patent phase (low parasitaemia or aparasitaemic periods). In animals that presented a better control of parasitaemia, IL-6 and IFNγ increased during most of the trial period. On the other hand, the cow that presented reduction of IL-1ß, IL-2, and TNFα during the entire period did not control parasitaemia properly. A balance between the Th1 and Th2 profile is beneficial for parasite control and animal health. The results found in the present study are a first step towards elucidating the dynamics of cattle's inflammatory response against T. vivax, requiring future studies focusing on the role of key cytokines on the controlling of parasitaemia in different stages of bovine trypanosomosis.

9.
Evolution ; 75(6): 1361-1376, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33860933

RESUMO

Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate repeated phenotypic patterns in different parts of a species' range. We investigated whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in the dewlap colors of Amazon Slender Anoles, Anolis fuscoauratus. To this aim, we characterized dewlap diversity in the field with respect to population genetic structure and evolutionary relationships, assessed whether dewlap phenotypes are associated with climate or landscape variables, and tested for nonrandom associations in the distributions of A. fuscoauratus phenotypes and sympatric Anolis species. We found that dewlap colors vary among but not within sites in A. fuscoauratus. Regional genetic clusters included multiple phenotypes, while populations with similar dewlaps were often distantly related. Phenotypes did not segregate in environmental space, providing no support for optimized signal transmission at a local scale. Instead, we found a negative association between certain phenotypes and sympatric Anolis species with similar dewlap color attributes, suggesting that interactions with closely related species promoted dewlap divergence among A. fuscoauratus populations. Amazon Slender Anoles emerge as a promising system to address questions about parallel trait evolution and the contribution of signaling traits to speciation.


Assuntos
Deriva Genética , Lagartos/genética , Caracteres Sexuais , Simpatria , Animais , Evolução Biológica , Clima , Meio Ambiente , Genética Populacional , Lagartos/classificação , Fenótipo , Pigmentação/genética , América do Sul
10.
Zootaxa ; 4758(3): zootaxa.4758.3.9, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32230135

RESUMO

The aim of this study was to analyse morphological and molecular (ITS region) characteristics for eight species of mites in the family Macrochelidae that are present in cattle manure in Brazil. Six of these species were already known in Brazil and, for five of these, both tools (morphology and phylogeny) were concordant regarding all the trees used. The species G. saprophila and M. scutatus were reported in the present study for the first time in Brazil. The data obtained in this study suggest that the molecular analysis corroborated the morphological identification in most species of macrochelids. The results also demonstrate the need to correlate identifications through dichotomous keys, by using phylogenetic studies to better distinguish cryptic species.


Assuntos
Ácaros , Animais , Brasil , Bovinos , Esterco , Filogenia
11.
Rev Bras Parasitol Vet ; 28(4): 671-676, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800889

RESUMO

Ticks of the Amblyomma cajennense complex present high infestation rates. These ticks transmit the bacterium Rickettsia rickettsii, which causes Brazilian Spotted Fever. For this reason, an integrated tick control system was adopted on a farm in the municipality of Itu, state of São Paulo. On this farm, which borders the Tietê river, domestic animals are in contact with populations of capybaras. Six locations were monitored and evaluated between the years of 2015 and 2017. During this work 1271 nymphs and adult ticks were caught, all of them from the Amblyomma sculptum species, except for a single individual from the Amblyomma dubitatum species. The integrated tick management reduced the overall infestation levels to zero. Adult tick population dropped in the first year of the study, while larvae population dropped in the second year. Nymph population dropped in both years, decreasing in higher numbers in the first year. The estimated mean infestation levels for all of the tick's life cycle forms in the six monitored spots did not reach one individual in the end of the study. Estimated mean infestation levels for nymphs in these places equaled zero.


Assuntos
Cavalos/parasitologia , Ixodidae/microbiologia , Roedores/parasitologia , Controle de Ácaros e Carrapatos/métodos , Animais , Brasil , Doenças Endêmicas , Fazendas , Febre Maculosa das Montanhas Rochosas/transmissão , População Rural
12.
Rev. bras. parasitol. vet ; 28(4): 671-676, Oct.-Dec. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1057992

RESUMO

Abstract Ticks of the Amblyomma cajennense complex present high infestation rates. These ticks transmit the bacterium Rickettsia rickettsii, which causes Brazilian Spotted Fever. For this reason, an integrated tick control system was adopted on a farm in the municipality of Itu, state of São Paulo. On this farm, which borders the Tietê river, domestic animals are in contact with populations of capybaras. Six locations were monitored and evaluated between the years of 2015 and 2017. During this work 1271 nymphs and adult ticks were caught, all of them from the Amblyomma sculptum species, except for a single individual from the Amblyomma dubitatum species. The integrated tick management reduced the overall infestation levels to zero. Adult tick population dropped in the first year of the study, while larvae population dropped in the second year. Nymph population dropped in both years, decreasing in higher numbers in the first year. The estimated mean infestation levels for all of the tick's life cycle forms in the six monitored spots did not reach one individual in the end of the study. Estimated mean infestation levels for nymphs in these places equaled zero.


Resumo Em virtude de alta infestação por carrapatos do complexo Amblyomma cajennense, parasitos que transmitem a bactéria Rickettsia rickettsii, causadora da Febre Maculosa Brasileira, adotou-se um sistema de controle integrado dos carrapatos numa propriedade rural localizada no munícipio de Itu - SP. Na propriedade, que margeia o rio Tietê, os animais domésticos mantinham contato com populações de capivaras. Seis locais foram avaliados e monitorados nos anos de 2015 a 2017. Dentre os 1271 espécimes capturados (adultos e ninfas) um foi identificado como Amblyomma dubitatum e os demais com Amblyomma sculptum. De um modo geral, houve controle da infestação de carrapatos visto que todos os estágios ao final de 2017 apresentaram níveis próximos ou igual a zero. A população de adultos teve queda no primeiro ano e a de larvas no segundo. As ninfas apresentaram queda nos dois anos, sendo mais acentuada no primeiro ano. A média da estimativa do nível de infestação para cada estágio do carrapato nos seis locais monitorados não chegou a 1 indivíduo ao final do experimento, sendo que a média da estimativa para as ninfas foi de zero em todos esses locais.


Assuntos
Animais , Roedores/parasitologia , Controle de Ácaros e Carrapatos/métodos , Ixodidae/microbiologia , Cavalos/parasitologia , População Rural , Brasil , Febre Maculosa das Montanhas Rochosas/transmissão , Doenças Endêmicas , Fazendas
13.
Acta Cir Bras ; 34(6): e201900605, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31432996

RESUMO

PURPOSE: To evaluate the use of adipose-derived stem cells (ADSC) in reducing the necrosis area in an experimental model of cutaneous ischemic flap in rats submitted to subcutaneous nicotine injection to simulate a smoker patient. METHODS: In an experimental study, 30 rats were enrolled and divided into two experimental groups of 15 animals all submitted to a subcutaneous nicotine injection to create ischemic cutaneous flaps on their backs. Other 10 animals were used only to obtain adipose tissue derived stem cells (ADSC). The first group (n=15) received ADSC treatment at the end of surgery while the other group, the control (n=15), received no other interventions. After euthanasia, a decal was performed on the whole area of the flap, accurately defining the transition from necrosis to healthy region. Photos of all animals were collected and evaluated by scales standardized by Paint-Autocad- 2015 software to define the area of flap necrosis in each rat. Student T test was performed to compare the groups, considering a p< 0.05 significant. Data were analyzed using SPSS IBM® 18 version. RESULTS: Through the analysis of the images by the program Paint-Autocad-2015 and the area of decal obtained by the transparent sheet, we obtained a mean of 46% necrosis of the total area of the flap in the treatment group and 69.4% in the control group. In the descriptive analysis, a mean of 3.7 cm of necrosis CI 95% (3.2 - 4.2) was evident in the treatment group whereas a mean value of 5.56 CI 95% (5.2 - 5.9) was found in control group, with p value <0.001 for this comparison. CONCLUSION: The application of adipose-derived stem cells reduces the percentage of necrosis in an experimental model of randomized cutaneous flap in rats submitted to subcutaneous nicotine injection.


Assuntos
Adipócitos/transplante , Tecido Adiposo/transplante , Cicatriz/terapia , Necrose/prevenção & controle , Nicotina/efeitos adversos , Animais , Modelos Animais de Doenças , Sobrevivência de Enxerto , Masculino , Necrose/induzido quimicamente , Nicotina/administração & dosagem , Ratos
14.
Rev. bras. parasitol. vet ; 28(3): 508-513, July-Sept. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1042532

RESUMO

Abstract Toxoplasmosis is an important zoonosis for pregnant women and immunosuppressed people. The pig population also becomes infected by this pathogen, and undercooked or raw meat is an important source of infection for humans. The aims of the present study were to evaluate the rate of exposure of pigs to T. gondii in the municipality of Mossoró, Rio Grande do Norte and seek to identify associations with possible risk factors. Blood samples were collected from 412 pigs and were analyzed using the immunofluorescence assay. Among these 412 serum samples, 40.7% were seropositive for T. gondii. The IgG antibody titers were 64 (56 specimens), 128 (32), 256 (37), 512 (23), 1024 (14), 2048 (5) and 4046 (1). Seropositivity for T. gondii was found to be related (p-value < 0.05) to the following factors: female gender, semi-confined rearing system, use of well water, dewormed animals, presence of cats, goats, sheep, mice and vultures on the farm and carcasses left on the ground. In contrast, seropositivity was not related (p-value < 0.05) to the age of the pigs, type of facility or feeding with human food remains. Preventive measures need to be adopted on the farms studied here, with the aim of decreasing the animals' intake of sporulated oocysts.


Resumo A toxoplasmose é uma importante zoonose para mulheres grávidas e pessoas imunossuprimidas. Os suínos também são infectados por este patógeno; e a carne crua ou malcozida é uma importante fonte de infecção para o ser humano. O objetivo do presente trabalho foi avaliar a taxa de exposição suína à T. gondii no município de Mossoró, Rio Grande do Norte e identificar associações com possíveis fatores de risco. Amostras de sangue foram coletadas em tubos sem anticoagulante e o soro foi separado de 412 porcos e analisadas pelo ensaio de imunofluorescência. Dentre as 412 amostras de soro, 40,7% foram positivas para T. gondii. Os títulos para o anticorpo IgG foram 64 (56 amostras); 128 (32); 256 (37); 512 (23); 1024 (14); 2048 (5) e 4046 (1). A soropotividade para T. gondii foi relacionada (p-valor < 0,05) aos seguintes fatores: gênero feminino, sistema de criação de semi-confinamento, uso de água de poço, animais vermifugados, presença de gatos, cabras, ovelhas, ratos e urubus na fazenda e carcaças deixadas à céu aberto. Em contrapartida, a soropositividade não foi relacionada (p-valor < 0,05) à idade dos suínos, tipo de instalações ou alimentação com restos de comida humana. As adoções de medidas preventivas são necessárias na propriedade estudada, objetivando diminuir a ingestão de oocistos esporulados pelos animais.


Assuntos
Animais , Masculino , Feminino , Suínos/parasitologia , Toxoplasma/imunologia , Anticorpos Antiprotozoários/sangue , Toxoplasmose Animal/epidemiologia , Brasil/epidemiologia , Estudos Soroepidemiológicos , Fatores de Risco , Técnica Indireta de Fluorescência para Anticorpo/veterinária
15.
Rev Bras Parasitol Vet ; 28(2): 203-209, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31188948

RESUMO

Livestock infections by Trypanosoma vivax have been occurring with increasing frequency, mainly due to the presence of animals with subclinical infections and without apparent parasitaemia, making diagnosis challenging. The aim of the present study was to evaluate several techniques used for T. vivax diagnosis in order to assess the best way of using them during the course of the disease. Molecular methods demonstrated higher rates of detection than parasitological methods, detecting 33 of the 54 (61.1%) known positive samples, while the hematocrit centrifugation technique (best parasitological test) detected only 44.4%. The serological methods, IFAT and ELISA, detected seropositivity in 51 of the 54 (94.4%) and 49 of the 54 (90.7%) known positive samples, respectively. Despite being highly sensitive, the latter only demonstrates exposure to the infectious agent and does not indicate whether the infection is active. The present study was the first to use the qPCR for a South American isolate, improving disease detection and quantification. Furthermore, the analyses revealed that the patent phase of the disease may extend up to 42 days, longer than previously reported. The combination of several diagnostic techniques can lower the frequency of false negative results and contributes toward better disease control.


Assuntos
Ensaio de Imunoadsorção Enzimática/veterinária , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Trypanosoma vivax , Tripanossomíase Africana/diagnóstico , Animais , Bovinos , Trypanosoma vivax/genética , Trypanosoma vivax/imunologia , Tripanossomíase Africana/veterinária
16.
Rev Bras Parasitol Vet ; 28(3): 508-513, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31188949

RESUMO

Toxoplasmosis is an important zoonosis for pregnant women and immunosuppressed people. The pig population also becomes infected by this pathogen, and undercooked or raw meat is an important source of infection for humans. The aims of the present study were to evaluate the rate of exposure of pigs to T. gondii in the municipality of Mossoró, Rio Grande do Norte and seek to identify associations with possible risk factors. Blood samples were collected from 412 pigs and were analyzed using the immunofluorescence assay. Among these 412 serum samples, 40.7% were seropositive for T. gondii. The IgG antibody titers were 64 (56 specimens), 128 (32), 256 (37), 512 (23), 1024 (14), 2048 (5) and 4046 (1). Seropositivity for T. gondii was found to be related (p-value < 0.05) to the following factors: female gender, semi-confined rearing system, use of well water, dewormed animals, presence of cats, goats, sheep, mice and vultures on the farm and carcasses left on the ground. In contrast, seropositivity was not related (p-value < 0.05) to the age of the pigs, type of facility or feeding with human food remains. Preventive measures need to be adopted on the farms studied here, with the aim of decreasing the animals' intake of sporulated oocysts.


Assuntos
Anticorpos Antiprotozoários/sangue , Suínos/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Brasil/epidemiologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Masculino , Fatores de Risco , Estudos Soroepidemiológicos
17.
Rev. bras. parasitol. vet ; 28(2): 203-209, Apr.-June 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1013736

RESUMO

Abstract Livestock infections by Trypanosoma vivax have been occurring with increasing frequency, mainly due to the presence of animals with subclinical infections and without apparent parasitaemia, making diagnosis challenging. The aim of the present study was to evaluate several techniques used for T. vivax diagnosis in order to assess the best way of using them during the course of the disease. Molecular methods demonstrated higher rates of detection than parasitological methods, detecting 33 of the 54 (61.1%) known positive samples, while the hematocrit centrifugation technique (best parasitological test) detected only 44.4%. The serological methods, IFAT and ELISA, detected seropositivity in 51 of the 54 (94.4%) and 49 of the 54 (90.7%) known positive samples, respectively. Despite being highly sensitive, the latter only demonstrates exposure to the infectious agent and does not indicate whether the infection is active. The present study was the first to use the qPCR for a South American isolate, improving disease detection and quantification. Furthermore, the analyses revealed that the patent phase of the disease may extend up to 42 days, longer than previously reported. The combination of several diagnostic techniques can lower the frequency of false negative results and contributes toward better disease control.


Resumo Infecções por Trypanosoma vivax têm ocorrido com frequência crescente em animais de produção, principalmente pela aquisição de animais com infecções subclínicas e sem aparente parasitemia, o que dificulta o diagnóstico. O objetivo do presente estudo foi avaliar várias técnicas empregadas para o diagnóstico de T. vivax, a fim de verificar a melhor maneira de utilizá-las durante o curso da doença. Os métodos moleculares demonstraram maiores taxas de detecção que os métodos parasitológicos, detectando 33 das 54 (61,1%) amostras sabidamente positivas, enquanto a técnica de hemoconcentração (melhor teste parasitológico) detectou apenas 44,4%. Os métodos sorológicos, RIFI e ELISA, detectaram soropositividade em 51 das 54 (94,4%) e 49 das 54 (90,7%) amostras sabidamente positivas, respectivamente. Apesar de serem altamente sensíveis, estes testes apenas demonstram a exposição ao agente infeccioso, e não indicam se a infecção permanece ativa. O presente estudo foi o primeiro a utilizar a qPCR para um isolado sul-americano, melhorando sua detecção e quantificação. Além disso, as análises revelaram que a fase patente da doença pode se estender por até 42 dias após a infecção, sendo maior que anteriormente relatado. A combinação de várias técnicas de diagnóstico pode evitar a frequência de resultados falso-negativos e contribuir para um melhor controle da doença.


Assuntos
Animais , Bovinos , Tripanossomíase Africana/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Trypanosoma vivax/genética , Trypanosoma vivax/imunologia , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Tripanossomíase Africana
18.
An Acad Bras Cienc ; 91(suppl 1): e20170976, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29791565

RESUMO

Body-size is significantly correlated with the number of vertebrae (pleomerism) in multiple vertebrate lineages, indicating that somitogenesis process is an important factor dictating evolutionary change associated to phyletic allometry and, consequently, species fitness and diversification. However, the role of the evolution of extreme body sizes (dwarfism and gigantism) remains elusive in snakes, mainly with respect to postnatal ontogeny in dietary preferences associated with evolution of gigantism in many lineages. We described herein a new species in the highly diversified and species-rich genus Atractus on the basis of four specimens from the southeastern slopes of the Ecuadorian Andes. The new species is morphologically similar and apparently closely related to two other allopatric giant congeners (A. gigas and A. touzeti), from which it can be distinguished by their distinct dorsal and ventral coloration, the number of supralabial and infralabial scales, the number of maxillary teeth, and relative width of the head. In addition, we discuss on the ontogenetic trajectories hypotheses and dietary specializations related to evolution of gigantism in the goo-eaters genus Atractus.


Assuntos
Tamanho Corporal , Comportamento Alimentar/fisiologia , Serpentes/anatomia & histologia , Animais , Evolução Biológica , Equador , Feminino , Serpentes/classificação , Serpentes/fisiologia
19.
Acta cir. bras ; 34(6): e201900605, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1019262

RESUMO

Abstract Purpose To evaluate the use of adipose-derived stem cells (ADSC) in reducing the necrosis area in an experimental model of cutaneous ischemic flap in rats submitted to subcutaneous nicotine injection to simulate a smoker patient. Methods In an experimental study, 30 rats were enrolled and divided into two experimental groups of 15 animals all submitted to a subcutaneous nicotine injection to create ischemic cutaneous flaps on their backs. Other 10 animals were used only to obtain adipose tissue derived stem cells (ADSC). The first group (n=15) received ADSC treatment at the end of surgery while the other group, the control (n=15), received no other interventions. After euthanasia, a decal was performed on the whole area of the flap, accurately defining the transition from necrosis to healthy region. Photos of all animals were collected and evaluated by scales standardized by Paint-Autocad- 2015 software to define the area of flap necrosis in each rat. Student T test was performed to compare the groups, considering a p< 0.05 significant. Data were analyzed using SPSS IBM® 18 version. Results Through the analysis of the images by the program Paint-Autocad-2015 and the area of decal obtained by the transparent sheet, we obtained a mean of 46% necrosis of the total area of the flap in the treatment group and 69.4% in the control group. In the descriptive analysis, a mean of 3.7 cm of necrosis CI 95% (3.2 - 4.2) was evident in the treatment group whereas a mean value of 5.56 CI 95% (5.2 - 5.9) was found in control group, with p value <0.001 for this comparison. Conclusion The application of adipose-derived stem cells reduces the percentage of necrosis in an experimental model of randomized cutaneous flap in rats submitted to subcutaneous nicotine injection.


Assuntos
Animais , Masculino , Ratos , Tecido Adiposo/transplante , Cicatriz/terapia , Adipócitos/transplante , Necrose/prevenção & controle , Nicotina/efeitos adversos , Modelos Animais de Doenças , Sobrevivência de Enxerto , Necrose/induzido quimicamente , Nicotina/administração & dosagem
20.
PeerJ ; 6: e4941, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30013824

RESUMO

Amphibians are probably the most vulnerable group to climate change and climate-change associate diseases. This ongoing biodiversity crisis makes it thus imperative to improve the taxonomy of anurans in biodiverse but understudied areas such as Amazonia. In this study, we applied robust integrative taxonomic methods combining genetic (mitochondrial 16S, 12S and COI genes), morphological and environmental data to delimit species of the genus Amazophrynella (Anura: Bufonidae) sampled from throughout their pan-Amazonian distribution. Our study confirms the hypothesis that the species diversity of the genus is grossly underestimated. Our analyses suggest the existence of eighteen linages of which seven are nominal species, three Deep Conspecific Lineages, one Unconfirmed Candidate Species, three Uncategorized Lineages, and four Confirmed Candidate Species and described herein. We also propose a phylogenetic hypothesis for the genus and discuss its implications for historical biogeography of this Amazonian group.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...