Publications by authors named "Alexandre R Silva"

Guanabara Bay, located at Rio de Janeiro, Brazil, is a highly urbanized and polluted estuary that houses different port areas, shipyards, and marinas of intense maritime traffic. This infrastructure is widely associated with the introduction and spread of non-native sessile species. A rapid assessment of non-native benthic sessile species conducted in the bay in late 2022 across 19 sites identified a total of 83 taxa, both native and non-native, classified into the following main groups: one Cyanophyta, 13 Macroalgae, 14 Porifera, 11 Cnidaria, six Bryozoa, five Annelida, 10 Mollusca, six Crustacea, 10 Echinodermata, and seven Ascidiacea.

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This work aims to study the major salivary gland morphology of peccaries during their growth. The glands were analyzed using macroscopic description, light microscopy, electron microscopy, histochemistry, and immunohistochemistry. Topographically, the salivary glands resemble other animals, including domestic animals and pigs.

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The establishment of fibroblast lines enables several applications from the formation of biobanks for the conservation of biodiversity to the use of these cells in physiological and toxicological assays. Considered a species vulnerable to extinction, the characterization of fibroblastic lines of northern tiger cat would contribute to its conservation. Therefore, we established and characterized fibroblasts derived from northern tiger cat during extended passage (third, seventh, and eleventh passages) and cryopreservation with regard to the morphology, viability, apoptotic classification, metabolism, proliferative activity, and oxidative stress by reactive oxygen species (ROS) levels and mitochondrial membrane potential (ΔΨm).

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The effects of antibiotics on sperm longevity in collared peccary () fresh diluted semen was evaluated. Semen samples from six adult males were collected by electroejaculation and diluted in Tris-citrate-fructose alone (control) and plus streptomycin-penicillin (2 mg/ml-2000 IU/ml) or gentamicin (70 µg/ml). Membrane integrity and functionality, mitochondrial activity and sperm morphology were assessed subjectively.

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For the development of efficient management and conservation strategies for wild rodent species, understanding the aspects related to their reproduction, including the interaction of this physiological function with the environment, is essential. This study aimed to evaluate the impacts of weather changes derived from a semiarid region's dry and rainy seasons on the epididymal sperm characteristics of red-rumped agouti (Dasyprocta leporina), a histricognath rodent, still little studied, which inhabits the Brazilian Caatinga. The sperm from the epididymal cauda of 14 agoutis were collected, seven individuals per season (dry and rainy).

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Background: In vitro culture of fibroblasts is a technique based on cell isolation, physiological characterization, and cryopreservation. This technique has not been described for Galea spixii, therefore, it can be used to learn about its cellular biology and genetic diversity.

Objective: We established fibroblast lines of six G.

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Article Synopsis
  • The study assessed how different culture media and concentrations of GDNF affect the in vitro culture of testicular tissues from prepubertal collared peccaries over 28 days.
  • Using Dulbecco's modified essential medium (DMEM) and StemPro-34 SFM, researchers found that the StemPro medium with 10 ng/mL GDNF led to better morphology scores compared to DMEM.
  • While cell viability remained consistent across treatments (~70%), only DMEM plus 10 ng/mL GDNF notably improved cellular proliferation by Days 14 and 28, indicating the importance of GDNF for cell survival and growth in cultured testicular tissue.
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: The study cohort comprised five patients, each presenting with unilateral high axial myopia and classic clinical features of HES, including large angle esotropia, hypotropia, and restricted abduction and supraduction. All patients displayed evident superotemporal globe prolapse on MRI imaging, corresponding to the downward displacement of the LR muscle and medial shift of the SR muscle.Following the surgical procedure, all patients demonstrated significant improvements in both vertical and horizontal deviations, effectively addressing the primary clinical manifestations of HES.

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To assist in the conservation of collared peccary, it is important to strengthen semen processing protocols. The aim of this study was to compare the effects of different commercial extenders (BTS; NUTRIXcell+ and PRIMXcell Ultra) and TRIS + egg yolk on the functional and morphological aspects of collared peccary semen stored at 17 °C for 48 hours. Ten ejaculates obtained by electroejaculation were divided into 4 aliquots and diluted in the respective extenders, then stored in a biological incubator at 17 °C for 12, 24, 36, and 48 hours.

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We verified the possibility of cooling peccary semen for 4, 24, and 48 h before cryopreservation, using different dilution media (TRIS + egg yolk (20%) and PRIMXcell Ultra). Ten ejaculates were divided equally into six aliquots and then diluted. Two aliquots were stored in a biological incubator (4 h), and the remaining aliquots were stored in a commercial container, the Botutainer (24 and 48 h), both at 5 °C.

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Establishing new somatic cell cultures has raised significant attention as an effective and convenient way to preserve genetic samples for different applications. Although many lines have been established in model animals, none derived from six-banded armadillo species is currently available. We report the successful isolation and characterization of fibroblasts from six-banded armadillos, evaluating the cell quality after extended culture and cryopreservation.

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Article Synopsis
  • - The study aimed to evaluate various aspects of spermatozoa in the greater rhea, including their movement, viability and membrane integrity, as well as differences between sperm from the epididymis and vas deferens.
  • - Semen samples from 7 adult rheas showed that the sperm had an average motility of 14.6%, with viability rates varying between 64.6% and 72.1% depending on the staining method used.
  • - The research established new reference values for evaluating rhea sperm, which can aid in improving sperm handling and freezing methods for this species.
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This study investigated whether the origin of sperm (epididymal vs. ejaculate) affects the cryopreservation efficiency in agouti (Dasyprocta leporina). Five sexually mature agoutis underwent electroejaculation, resulting in obtaining four semen samples.

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This study is aimed at evaluating the effect of different extenders on the cryopreservation of semen from Africanized honeybees (A. mellifera). Semen from honeybee drones from 10 different colonies was obtained by endophallus exposure technique and immediately evaluated for motility, viability using fluorescent probes, functional membrane integrity using the water test, and morphology.

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  • Semen preservation is an important biotechnology for conserving bird genetics, especially for species with dwindling populations, but it faces challenges like limited successful techniques in wild birds.
  • * Current issues include difficulties in handling birds, semen contamination, small sample sizes, and ineffective preservation methods.
  • * Research is exploring new collection methods, the use of antioxidants, alternative storage solutions, and optimizing freezing rates to enhance preservation outcomes for wild bird semen.
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The use of assisted reproductive techniques, such as chilled semen, contributes to the maintenance and genetic improvement of canine breeding. The INRA-96 extender is a commercially available, chemically defined medium that was initially developed for the preservation of equine semen and exhibits preservation potential in the canine species. This research aims to evaluate the INRA-96 extender as an alternative for the short-term preservation of canine semen in terms of sperm quality parameters such as motility and kinetic parameters, integrity and functionality of the plasma membrane in fresh and chilled-rewarmed samples, as well as the sperm-binding ability using the perivitelline membrane of the chicken egg as an indicator of the fertilizing capacity of the preserved semen.

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Considering the relevance of establishing biodiversity conservation tools, the study aimed to investigate the TCM199 supplemented with different follicle-stimulating hormone (FSH) concentrations on survival and development of fresh and vitrified preantral follicles enclosed in red-rumped agouti ovarian tissues cultured . In the first experiment, six pairs of ovaries were fragmented and cultured for 6 days according to groups: 10 ng/mL pFSH (FSH10 group) and 50 ng/mL (FSH50 group). Non-cultured tissues were considered as a control.

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Methods for seminal plasma (SP) removal and the selection of collared peccary sperm for fertilization were compared. The experiments evaluated the following: the (I) impact of centrifugation for SP removal before swim-up for sperm selection and (II) a comparison of different Percoll gradient densities (PG 45-90% and PG 35-70%). Non-selected sperm served as the control.

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Article Synopsis
  • * Sperm count increased from the epididymis (201.0 × 10) to the vas deferens (378.0 × 10), and motility improved from 37% to 58.5% during this transition, while the proportion of normal sperm remained high at 75.6%.
  • * Scanning electron microscopy revealed that sperm dimensions, including acrosome and tail lengths, were longer in the vas deferens, indicating that rhea spermatozoa mature as they move through the reproductive tract
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Knowledge on male reproductive physiology is essential for the development of effective conservation strategies. This study investigated the influence of environmental variables on certain reproductive metrics in white-lipped peccaries (Tayassu pecari) raised in the Atlantic Forest. After anesthetization, testicular and cauda epididymis biometry were evaluated in nine adult male individuals subjected to electroejaculation.

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  • Biological Resource Banks (BRB) are essential for conserving animal biodiversity, especially for species threatened with extinction, with over 38,500 at risk out of 138,300 surveyed.
  • BRBs now include ovarian and testicular tissues, which can be used to create mature gametes for Assisted Reproduction Technologies and help understand infertility mechanisms.
  • Recent advancements in BRBs focus on preserving wild species from Brazil's Caatinga biome, with ongoing research on various animals like collared peccaries and using domestic species as models for these efforts.
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We evaluated the effects of detergents based on sodium dodecyl sulfoxide (SDS) on the functional parameters of collared peccary frozen-thawed sperm. Semen aliquots from ten individuals were diluted in a Tris-egg yolk-glycerol extender alone or with 0.5% Equex STM paste or SDS (at 0.

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  • The study explores the role of microRNAs (miRNAs) in the ovarian and testicular tissues of domestic cats, aiming to understand their involvement in gonadal function and development.
  • Researchers analyzed 20 ovarian and 20 testicular samples from 15 cats, identifying 183 known miRNA precursors and 52 novel candidates specific to felines.
  • The findings suggest that certain miRNAs may play crucial roles in testicular development and the ovarian response to stress from preservation methods, ultimately enhancing our understanding of cat gonadal biology and fertility preservation techniques.
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The objective was to investigate the effects of semen freezing extender supplementation with antibiotics on bacterial load of semen samples, sperm functional and morphological metrics in the collared peccary. Fresh ejaculates from 10 males were extended in Tris-egg yolk-glycerol supplemented or not (control) with gentamicin (70 μg/mL) streptomycin-penicillin (SP; 1 mg/mL-1000 IU/mL) or and cryopreserved in liquid nitrogen. Bacterial load, sperm motility patterns, morphology, membrane functionality and integrity, mitochondrial activity, chromatin integrity and sperm-binding ability were evaluated in fresh and frozen-thawed samples.

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Morphological studies of the oropharyngeal cavity of chelonians have become an interesting tool in the understanding of evolutionary processes associated with feeding habits in aquatic animals and the transition from aquatic to terrestrial forms. In this context, the aim of the present study was to describe the oropharyngeal cavity floor morphology of hawksbill sea turtle (Eretmochelys imbricata) hatchlings. Ten dead hatchlings of undefined sex were obtained from nests hatched on the coast of the state of Rio Grande do Norte, Brazil.

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