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  • He holds a degree in Veterinary Medicine from Universidade Federal de Uberlândia (1987), MSc (1992) and Ph.D. (1998) ... moreedit
Campylobacter jejuni produces several virulence factors to colonize the poultry gastrointestinal tract. In commercial broiler chickens, this colonization appears to be predominantly commensal, with C. jejuni found in large numbers in the... more
Campylobacter jejuni produces several virulence factors to colonize the poultry gastrointestinal tract. In commercial broiler chickens, this colonization appears to be predominantly commensal, with C. jejuni found in large numbers in the intestinal mucosa. The consumption of contaminated chicken meat is the major source of human campylobacteriosis, which makes the understanding of the mechanisms of colonization important in the search for alternatives for the treatment and prevention of such zoonosis. In the past few years, the research on the colonization mechanism of C. jejuni in chickens has significantly advanced. This chapter summarizes our increasing knowledge about the main virulence factors involved in the colonization of poultry.
... DANIEL CORTES BERETTA,1 DUVALDO EURIDES,2 JULIETA RONDINI ENGRACIA DE MORAES,3 EDINALDO CARVALHO GUIMARÃES,4 WESLAY SOUZA ... Segundo NESSLER & MASS (1985), em um estudo com DC em tendões de coelho in vitro, distâncias inferiores... more
... DANIEL CORTES BERETTA,1 DUVALDO EURIDES,2 JULIETA RONDINI ENGRACIA DE MORAES,3 EDINALDO CARVALHO GUIMARÃES,4 WESLAY SOUZA ... Segundo NESSLER & MASS (1985), em um estudo com DC em tendões de coelho in vitro, distâncias inferiores a ...
Rev. Bras. Med. Vet., 35(Supl. 1):79-83, dezembro 2013 79 RESUMO. O plasma rico em plaquetas (PRP) é utilizado para liberar fatores de crescimento em al-tas concentrações no local onde se pretende reparar uma lesão tecidual. Objetivou-se... more
Rev. Bras. Med. Vet., 35(Supl. 1):79-83, dezembro 2013 79 RESUMO. O plasma rico em plaquetas (PRP) é utilizado para liberar fatores de crescimento em al-tas concentrações no local onde se pretende reparar uma lesão tecidual. Objetivou-se avaliar macrosco-picamente e histologicamente o uso do PRP asso-ciado à bandagem úmida em feridas causadas por queimaduras, produzidas experimentalmente em coelhos. Duas queimaduras cutâneas de espessura total, de 2,5cm de diâmetro, foram produzidas na região dorsal, em 16 coelhos jovens. A ferida do an-tímero esquerdo serviu como grupo controle (GC), recebendo apenas água destilada e a do antímero di-reito (GT) foi embebida com PRP. Analisaram-se as feridas aos três, sete, 14 e 21 dias de pós-operatório
The objective of this work was to determine fertilization rates and embryonal recovery and to evaluate aspects of the early embryonal development. Eleven adult female dogs were used, with no defined breed. After the beginning of the... more
The objective of this work was to determine fertilization rates and embryonal recovery and to evaluate aspects of the early embryonal development. Eleven adult female dogs were used, with no defined breed. After the beginning of the natural estrus, these were mated and subjected to ovariohisterectomy on the 5th, 7th or 9th day postcoitus. Ovaries, tubes and uterine horns were separated. From the ovaries, the number of corpora lutea was determined. Tubes and uterine horns were washed separately in order to collect ovules and embryos, which were identified through the use of a stereomicroscope at 15x magnification. The fertilization rate was 94% and embryonal recovery 68.5%. On the fifth day, postcoitus embryos of up to eight cells were found in uterine tubes. Morulae or blastocysts were observed in uterine horns from the 9th day after recovery. On the basis of these results, it was concluded that the loss of structures can be due to the failure of their uptake by uterine tubes or dur...
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Com a descoberta de que a miocardiopatia dilatada, uma das patologias causadas pela carencia de taurina, poderia ser totalmente revertida com a suplementacao desse aminoacido houve uma grande fortificacao das dietas comerciais com o... more
Com a descoberta de que a miocardiopatia dilatada, uma das patologias causadas pela carencia de taurina, poderia ser totalmente revertida com a suplementacao desse aminoacido houve uma grande fortificacao das dietas comerciais com o mesmo. No entanto, poucos estudos foram realizados para se analisar os efeitos, a longo prazo, dessa ingestao excessiva de taurina nos diversos sistemas corporeos, principalmente no sistema reprodutivo. O objetivo deste trabalho foi determinar os efeitos do excesso de taurina no desempenho reprodutivo de gatas domesticas. Foram utilizadas 16 gatas domesticas, clinicamente saudaveis, sem raca definida e em idade reprodutiva. Esses animais foram divididos em dois grupos, sendo que ambos receberam a mesma dieta comercial seca e um dos grupos recebeu diariamente a suplementacao oral de 192mg de taurina, durante quatro meses. Apos esse periodo, todas as gatas copularam com gatos ferteis e foram ovariohisterectomizadas no sexto dia pos-copula, sendo realizada a coleta dos embrioes e a preparacao histologica dos ovarios para observacao em microscopia de luz, quantificando- se os foliculos ovarianos. Foi realizado o teste t de Student para comparacao entre os grupos das seguintes variaveis: numero corpos luteos, foliculos primordiais, primarios, secundarios e terciarios por area (mm2) de tecido cortical ovariano, numero total de embrioes e qualidade dos mesmos. O numero de embrioes foi maior no grupo que recebeu a suplementacao oral de taurina, nao havendo diferenca estatistica nas demais variaveis estudadas. O excesso induzido de taurina nao causou qualquer efeito adverso em gatas adultas em idade reprodutiva, que apresentaram ganho de peso, apetite, comportamento e ciclos estrais normais, havendo uma melhora no desempenho reprodutivo desses animais, que passaram a apresentar maior numero de embrioes, sem que os mesmos tivessem sua qualidade alterada. Esses resultados indicam que o uso da suplementacao oral de taurina pode representar uma alternativa para melhorar o desempenho reprodutivo de gatas de importância economica e/ou em risco de extincao mantidos em cativeiros.
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Objetivou-se caracterizar histologicamente o desenvolvimento ovariano pre-natal em fetos equinos sem raca definida, ressaltando surgimento e quantificacao de ovogonias e foliculos. Coletaramse 131 fetos em frigorifico, os quais foram... more
Objetivou-se caracterizar histologicamente o desenvolvimento ovariano pre-natal em fetos equinos sem raca definida, ressaltando surgimento e quantificacao de ovogonias e foliculos. Coletaramse 131 fetos em frigorifico, os quais foram mensurados quanto ao comprimento (cm) equivalente a distância cefalococcigea (“crown-rump?, CR), seguido de corte das gonadas e fixacao das amostras em Bouin por 24 horas. As idades foram estimadas pela formula de regressao DG = 22,623 + 4,2528 CR - 0,0124 CR² (r2 = 0,9869), na qual os dias de gestacao (DG) variam em funcao do CR. Prepararam-se cortes histologicos ovarianos de 7 μm de espessura, os quais foram corados com hematoxilina-eosina. O surgimento de ovogonias, foliculos primordiais, em crescimento e antrais foi verificado, respectivamente, em fetos com CR entre 4,1 e 6,5 cm (40 a 49 DG); 9,1 e 12,0 cm (60 a 69 DG); 23,1 e 29,0 cm (116 a 135 DG) e 50,1 e 65,0 cm (201 a 245 DG). A quantidade maxima de ovogonias, foliculos primordiais, em crescimento e antrais foi observada em fetos com CR entre 4,1 e 6,0 cm (40 a 49 DG); 16,1 e 23,0 cm (90 a 115 DG); 29,1 e 36,0 cm (136 a 155 DG) e 50,1 e 97,0 cm (201 a 320 DG), respectivamente.
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To evaluate the therapeutic activity of low-power laser (InGaAlP: 670 nm/30 mW), at doses of 90 J/cm(2), on the process of acute and chronic-phase repair of bone lesions of Wistar rats. Sixty-three adult males were divided into nine... more
To evaluate the therapeutic activity of low-power laser (InGaAlP: 670 nm/30 mW), at doses of 90 J/cm(2), on the process of acute and chronic-phase repair of bone lesions of Wistar rats. Sixty-three adult males were divided into nine groups subjected to bone injury, in order to form the following treatments: T1 (control); T2 (acute-phase); T3 (chronic-phase) which were subdivided into three subgroups (n=7), analyzed on the 9th, 17th and 28th days post-surgery, after a period of daily treatment with laser. The animals with acute-phase treatment presented a more extensive endochondral ossification process. Laser-treated animals showed significant increases in serum alkaline phosphatase levels and had an effect on biomechanical property, resulting in a gradual increase in bone stiffness. Laser therapy aided the bone consolidation process and favored the physiopathologic mechanisms involved in bone tissue repair, and its effects were more prominent when treatment started during the acute phase of the injury.
Muscular necrosis is a serious consequence of Bothrops snake bites that may lead to permanent loss of tissue or function. Myonecrosis may be due to injury to blood vessels, destabilization and/or rupture of plasma membrane, and... more
Muscular necrosis is a serious consequence of Bothrops snake bites that may lead to permanent loss of tissue or function. Myonecrosis may be due to injury to blood vessels, destabilization and/or rupture of plasma membrane, and inflammatory mechanisms triggered by different proteins from the snake venom. In this work we describe the isolation and partial functional characterization of a myotoxin from B. alternatus snake venom. The myotoxin was isolated by a combination of ion exchange and gel filtration chromatography and displayed a molecular weight of approximately 15,000, as estimated by SDS-PAGE under reducing conditions. In non-reducing conditions a protein band of approximately 25,000 was also observed, suggesting that its native form is a homodimer. The myotoxin induced myonecrosis, but had no proteolytic and phospholipase A₂ activities. The myotoxic activity was assessed on the basis of the histological and ultrastructural alterations induced by the toxin in the gastrocnemius skeletal muscle of Swiss mice. The toxin led to a series of drastic degenerative events characterized by extensive cellular destruction, loss of the arrangements of skeletal fibers, intense infiltration of inflammatory cells, fatty degeneration and hemorrhage. Electron microscopy analyses revealed that the myotoxin caused cell swelling, mitochondrial alterations and dilation of the sarcoplasmic reticulum, but did not affect the integrity of the muscle cell membranes. The myonecrosis caused by this toxin was related to the perturbation in the membrane permeability, intracellular alterations and inflammatory reaction.
The aim of this study was to assess in vitro sperm characteristics and pregnancies/AI (P/AI) of conventional and sex-sorted semen at timed-AI of suckled, multiparous Nelore cows. All cows (n=348) were submitted to a traditional... more
The aim of this study was to assess in vitro sperm characteristics and pregnancies/AI (P/AI) of conventional and sex-sorted semen at timed-AI of suckled, multiparous Nelore cows. All cows (n=348) were submitted to a traditional estradiol/progesterone(P4)-based protocol. At 48h after P4-device removal, the estrous behavior was recorded, and AI was performed with conventional or sex-sorted semen from two bulls. The following sperm assessments were performed: CASA, Hyposmotic Test, sperm morphometry and chromatin structure by TB staining. P/AI were reduced (P<0.001) for sex-sorted compared to conventional semen in cows expressing estrus (27vs47%) or not (11vs.37%). Membrane integrity (Bull1: 30.3±9.6 vs. 52.3±12.4%, P=0.01; Bull2: 24.5±3.0 vs. 48.7±1.6%, P=0.006) and sperm concentration (Bull1: 23.2±0.6 vs. 43.0±0.8x10⁶sperm/mL, P<0.001; Bull2: 25.1±2.8 vs. 42.1±0.7x10⁶sperm/mL; P<0.001) were reduced in sex-sorted compared to conventional semen, for both bulls. Total and progr...
The effect of three different hormonal protocols to prepare anestrous recipient mares on embryo survival was evaluated. The first group consisted of only progesterone administration (NE) 4 days before embryo transfer, while the recipients... more
The effect of three different hormonal protocols to prepare anestrous recipient mares on embryo survival was evaluated. The first group consisted of only progesterone administration (NE) 4 days before embryo transfer, while the recipients from the other two groups received a single administration of 2.5 mg of oestradiol benzoate (SE) 2 days earlier or 8 mg of oestradiol split in increasing doses for 5 consecutive days (LE) ending 3 days before progesterone treatment. The likelihood of recovering an embryo 2 days after transfer was 46.1% (6/13), 62.5% (5/8) and 85.7% (6/7) for recipient mares from the no oestrus, short and long oestrous groups respectively (p = .09). In conclusion, the presence and duration of oestradiol treatment before progesterone administration tended to influence the embryo survival in anestrous recipients 2 days after transfer. The surviving embryos recovered from the three different groups of recipients did not show any difference in size and morphology.
This study aimed to evaluate the ultrastructural morphometry of bovine embryos produced in vitro grown at different concentrations of antioxidants. After in vitro maturation and fertilization, the presumptive zygotes were assigned into... more
This study aimed to evaluate the ultrastructural morphometry of bovine embryos produced in vitro grown at different concentrations of antioxidants. After in vitro maturation and fertilization, the presumptive zygotes were assigned into five treatments. T1) without the addition of any antioxidants (negative control); T2) addition of 50μM/mL cysteamine; and T3, T4 and T5) adding 2.5μg/mL, 5.0μg/mL or 10.0μg/mL of the antioxidants derived from the oily extract from Lippia origanoides, respectively. On D7 of culture, the embryos in the blastocyst stage were fixed and prepared for electron transmission microscopy. These were evaluated for the proportion of cytoplasm-to-nucleus, cytoplasm-to-mitochondria, cytoplasm-to-vacuoles, cytoplasm-to-autophagic vacuoles and cytoplasm-to-lipid droplets. Blastocysts cultured in media containing oily extract of Lippia origanoides presented morphological characteristics such as high cell:mitochondria ratio and low cell:vacuoles and cell:autophagic vacu...
Reprodutores que possuem espermograma normal podem se comportar como subferteis ou passarem por periodos de subfertilidade. As alteracoes na descompactacao da cromatina dos espermatozoides em bovinos sao possiveis explicacoes encontradas... more
Reprodutores que possuem espermograma normal podem se comportar como subferteis ou passarem por periodos de subfertilidade. As alteracoes na descompactacao da cromatina dos espermatozoides em bovinos sao possiveis explicacoes encontradas para tais comportamentos. O presente trabalho foi delineado para correlacionar dois metodos para avaliacao da descompactacao da cromatina: analise computacional de esfregacos de semen corados com azul de toluidina e o SCSA (Sperm Chromatin Structure Assay). Quatorze amostras de semen de bovinos subferteis foram avaliadas com os dois metodos. Nos esfregacos de semen corados com AT foram avaliadas a descompactacao e heterogeneidade da cromatina. Com o SCSA avaliou-se a proporcao de cabecas de espermatozoides coradas em vermelho (descompactada) e em verde (compactada). Posteriormente foi realizado o teste de correlacao de Pearson entre as caracteristicas avaliadas. Foi verificada a existencia de uma correlacao positiva significativa entre o SCSA e a de...
The aim of this study was to evaluate the sperm head morphometry and chromatin condensation at different regions of the reproductive tract in bulls. Sperm smears of seminiferous tubules (ST), epididymis head (EH), body (EB), and tail... more
The aim of this study was to evaluate the sperm head morphometry and chromatin condensation at different regions of the reproductive tract in bulls. Sperm smears of seminiferous tubules (ST), epididymis head (EH), body (EB), and tail (ET), and ductus deferens (DD) were stained with toluidine blue. Afterwards, the sperm head morphometry and chromatin alteration types were evaluated by a computational image analysis. Overall, spermatozoa of ST had lower (P < 0.05) area (A), perimeter (P), width (W), length (L), ellipticity (E), and Fourier harmonics (F0, F1, and F2). The chromatin decondensation (CD) and heterogeneity (CH) were higher (P < 0.05) in the ST region and decreased (P < 0.0001) during the migration along the reproductive tract (ST - DD direction). Considering the factors extracted (Factors 1 and 2) by the principal component analysis, the parameters A, P, W, L, and F0 were responsible for ∼36% of the Factor 1, while the E, F0, F1, and anterior-posterior symmetry (APS) contributed ∼27% to Factor 2. Both, CD and CH were associated with Factor 1 in the EH and ET regions and Factor 2 in the ST. Also, a well-defined difference between sperm heads collected from the ST and DD regions was observed by canonical analysis. The distribution of each chromatin alteration type was recorded. The proportion of normal sperm was lower (P < 0.05) in ST compared to other regions. Moreover, the chromatin influenced the morphometry and sperm heads with whole chromatin alteration type showed a smaller (P < 0.05) A, P, W, L, and E. In summary, the epididymal maturation is important for chromatin compaction and final morphometry of the sperm head. Also, the identification and quantification of the sperm chromatin condensation in different regions of reproductive tract can be used as potential biomarkers to predict the fertility in bulls.
Uterocalin (P19) is a lipocalin protein that has binding activity for the provisioning of the embryo with lipids, including those essential for morphogenesis and pattern formation. Therefore, it is thought that P19 plays an important role... more
Uterocalin (P19) is a lipocalin protein that has binding activity for the provisioning of the embryo with lipids, including those essential for morphogenesis and pattern formation. Therefore, it is thought that P19 plays an important role in supporting the survival of the early embryo. Previous research has shown that the endometrium from acyclic mares expressed more P19 following a simulated long estrus: treatment of 8 mg of estradiol benzoate (EB) split over five consecutive days, followed by long-acting progesterone administration (LA-P4) 72 hours later, when compared to a single 2.5 mg EB treatment. The main objective of this study was to evaluate if a new long estrus protocol, with fewer EB administrations, also increases endometrial uterocalin expression. Fifteen mares were assigned to three groups: long estrus 5 administrations (LE5; a total of 8 mg of EB in increasing doses was given over five consecutive days, Day -7 to Day -3); long estrus 2 administrations (LE2; 3 and 5 mg EB were given on Day -7 and Day -4); and short estrus (SE; a single dose of 2.5 mg EB was administered on Day -2). All groups received LA P4 on day 0 (D0). Daily ultrasonography and blood collections were performed to assess uterine edema and estradiol and progesterone plasma concentrations, respectively. Endometrial biopsies were collected on Day 4 to evaluate P19 expression by RT-qPCR. There were no differences in P19 expression between groups LE2 and LE5. However, P19 expression was higher (P < .05) in the LE groups than in the SE group. Both LE protocols produced high uterine edema (score 2-3) for at least 6 days. There was no effect of group (LE2 or LE5) on overall estradiol and progesterone concentrations (P > .1). In conclusion, the two EB administrations protocol is more feasible for preparing acyclic recipient mares at field conditions. However, a positive effect of the LE protocols on embryo survival and viability in anestrous treated mares still needs to be confirmed.
ABSTRACT: This study describes an outbreak of avian poxvirus disease in previously pox-vaccinated turkeys in Brazil. The turkeys had suggestive gross lesions of cutaneous avian poxvirus in the skin of the head and cervical area without... more
ABSTRACT: This study describes an outbreak of avian poxvirus disease in previously pox-vaccinated turkeys in Brazil. The turkeys had suggestive gross lesions of cutaneous avian poxvirus in the skin of the head and cervical area without changes in the flock mortality rates. In the slaughterhouse, 30 carcasses were removed from the slaughter line to collect tissue from cutaneous lesions for histological analyses and characterization of the virus. The virus was identified by conventional polymerase chain reaction (PCR) and subsequent gene sequencing. Acanthosis, hyperkeratosis, and hydropic degeneration were seen on skin histopathology. Eosinophilic intracytoplasmic inclusion bodies (Bollinger) on keratinocytes were observed in 46.6% of the samples. Avian poxvirus DNA was detected on PCR in 83.3% of the total samples. PCR associated with histopathology had 93.3% of positivity for avian poxvirus. In the phylogenetic study, samples show 100% matching suggesting that the outbreak occurred...
Infertility or subfertility in bovine males may be related to spermatic microRNAs (miRNAs), whose function seems to be associated with the regulation of gene expression, degradation or storage of messenger RNAs (mRNAs) for later... more
Infertility or subfertility in bovine males may be related to spermatic microRNAs (miRNAs), whose function seems to be associated with the regulation of gene expression, degradation or storage of messenger RNAs (mRNAs) for later translation into early embryonic development. Thus, the purpose of this study was to identify differentially expressed miRNAs in semen samples from bulls (Bos taurus) with low and high efficiency in the in vitro embryo production (IVEP) and to evaluate if they can be used as markers of semen efficiency for IVEPs. In order to identify miRNA markers of semen efficiency in the in vitro embryo production, eight semen samples from each animal, one bull with high and two bulls with low efficiency in IVEPs were used to perform the RNAseq technique for miRNAs. Initially the samples were washed with PBS to remove the extender semen and subsequently were submitted to RNA extraction protocols performed according to procedures described by mirVanaâ„¢ miRNA Isolation Kit...
Resumo O objetivo detse artigo é de descrever um protocolo de isolamento das células mononucleares da medula óssea de coelhos, seguido de purificação celular por depleção negativa com o anticorpo monoclonal CD45 e posterior expansão em... more
Resumo O objetivo detse artigo é de descrever um protocolo de isolamento das células mononucleares da medula óssea de coelhos, seguido de purificação celular por depleção negativa com o anticorpo monoclonal CD45 e posterior expansão em meio de cultura MesenCult®. Dez coelhos machos adultos, da raça Nova Zelândia, com idade média de 1,0±0,2 anos e peso médio 3,5±0,24kg, foram utilizados para padronização da metodologia. O isolamento das células mononuclares da medula óssea foi realizado pelo gradiente de densidade Ficoll-paque® e a purificação e obtenção das células- pela depleção negativa com o anticorpo monoclonal CD45 em base imunomagnética. A população celular obtida foi expandida posteriormente em meio de cultura MesenCult®. No isolamento pelo gradiente de icoll-Paque® foi obtido um rendimento médio de 7,31x106 células/mL. Após purificação e obtenção das possíveis células-tronco mesenquimais pela base imunomagnética, houve um decréscimo do rendimento para 2,28x106 células/mL, ma...
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A protease, which we designate Eumiliin, was isolated from the latex of Euphorbia milii var. hislopii by a combination of ion-exchange chromatographic steps using DEAE-Sephacel and gel-filtration with Sephadex G-75. Eumiliin is a... more
A protease, which we designate Eumiliin, was isolated from the latex of Euphorbia milii var. hislopii by a combination of ion-exchange chromatographic steps using DEAE-Sephacel and gel-filtration with Sephadex G-75. Eumiliin is a monomeric protein with an apparent molecular mass of 30 kDa by SDS-PAGE under reducing conditions and gave one main peak at 29,814 KDa in MALDI-TOF/TOF mass spectrometry. Eumiliin has caseinolytic and fibrinogenolytic activities, but no hemorrhagic or defibrinating activities. The enzyme readily hydrolyzes the Aalpha-chain of fibrinogen and, more slowly, the Bbeta-chain. Its fibrinogenolytic activity is inhibited by beta-mercaptoethanol and leupeptin. In contrast, EDTA and benzamidine did not affect the activity of Eumiliin. The caseinolytic activity of Eumiliin had a pH optimum of 8.0 and was stable in solution at up to 40 degrees C; activity was completely lost at >or=80 degrees C. Intraplantar injection of Eumiliin (1-25 microg/paw) caused a dose- and time-dependent hyperalgesia, which peaked 1-5h after enzyme injection. Intraplantar injection of Eumiliin (1-25 microg/paw) also caused an oedematogenic response that was maximal after 1h. Morphological analyses indicated that Eumiliin induced an intense myonecrosis, with visible leukocyte infiltrate and damaged muscle cells 24h after injection.
This study aimed to evaluate whether the addition of resveratrol to vitrification/thawing medium improves the cryotolerance of preantral follicles enclosed in bovine ovarian fragments. Ovarian fragments were obtained from bovine fetuses... more
This study aimed to evaluate whether the addition of resveratrol to vitrification/thawing medium improves the cryotolerance of preantral follicles enclosed in bovine ovarian fragments. Ovarian fragments were obtained from bovine fetuses and distributed to the following groups: fresh ovarian fragments (control), vitrified (VIT), and vitrified with resveratrol (VIT + RESV). Overall, the mean percentage of normal follicles was greater (P < 0.05) in the VIT + RESV compared to the VIT group. Moreover, the probability of finding normal follicles was 2.5 greater (P < 0.05) in the VIT + RESV group. In class comparison, the primordial and transitional follicles have ∼3.0 times (P < 0.05) greater odds of being normal after vitrification compared to the secondary follicles. Additionally, a negative association (P < 0.05) was observed between the proportion of viable follicles and the stage of follicular development. ROS levels were similar (P > 0.05) between the VIT and VIT + RE...
Melipona scutellaris Latreille, 1811 (Hymenoptera, Apidae) is a pollinator of various native and cultivated plants. Because of the expansion of agriculture and the need to ensure pest control, the use of insecticides such as fipronil (FP)... more
Melipona scutellaris Latreille, 1811 (Hymenoptera, Apidae) is a pollinator of various native and cultivated plants. Because of the expansion of agriculture and the need to ensure pest control, the use of insecticides such as fipronil (FP) has increased. This study aimed to evaluate the effects of sublethal doses of FP insecticide on M. scutellaris at different time intervals (6, 12, and 24 h) after exposure, via individually analyzed behavioral biomarkers (locomotor activity, behavioral change) as well as the effect of FP on different brain structures of bees (mushroom bodies, antennal cells, and optic cells), using sub-individual cell biomarkers (heterochromatin dispersion, total nuclear and heterochromatic volume). Forager bees were collected when they were returning to the nest and were exposed to three different concentrations of FP (0.40, 0.040, and 0.0040 ng a.i/bee) by topical application. The results revealed a reduction in the mean velocity, lethargy, motor difficulty, para...

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