Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 507
Filtrar
1.
Development ; 151(17)2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39250533

RESUMO

The cell-intrinsic mechanisms underlying the decision of a stem/progenitor cell to either proliferate or differentiate remain incompletely understood. Here, we identify the transmembrane protein Lrig1 as a physiological homeostatic regulator of FGF2-driven proliferation and self-renewal of neural progenitors at early-to-mid embryonic stages of cortical development. We show that Lrig1 is expressed in cortical progenitors (CPs), and its ablation caused expansion and increased proliferation of radial/apical progenitors and of neurogenic transit-amplifying Tbr2+ intermediate progenitors. Notably, our findings identify a previously unreported EGF-independent mechanism through which Lrig1 negatively regulates neural progenitor proliferation by modulating the FGF2-induced IL6/Jak2/Stat3 pathway, a molecular cascade that plays a pivotal role in the generation and maintenance of CPs. Consistently, Lrig1 knockout mice showed a significant increase in the density of pyramidal glutamatergic neurons placed in superficial layers 2 and 3 of the postnatal neocortex. Together, these results support a model in which Lrig1 regulates cortical neurogenesis by influencing the cycling activity of a set of progenitors that are temporally specified to produce upper layer glutamatergic neurons.


Assuntos
Janus Quinase 2 , Glicoproteínas de Membrana , Camundongos Knockout , Células-Tronco Neurais , Neurogênese , Neurônios , Fator de Transcrição STAT3 , Transdução de Sinais , Animais , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Janus Quinase 2/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Camundongos , Neurogênese/genética , Neurônios/metabolismo , Neurônios/citologia , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Proliferação de Células , Córtex Cerebral/metabolismo , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Diferenciação Celular , Fatores de Crescimento de Fibroblastos/metabolismo , Proteínas do Tecido Nervoso
2.
Curr Res Insect Sci ; 6: 100094, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39262636

RESUMO

The calcium dependent Calpain proteases are modulatory enzymes with important roles in cell cycle control, development and immunity. In the fly model Drosophila melanogaster Calpain A cleaves Cactus/IkappaB and consequently modifies Toll signals during embryonic dorsal-ventral (DV) patterning. Here we explore the role of Calpains in the hemiptera Rhodnius prolixus, an intermediate germband insect where the Bone Morphogenetic Protein (BMP) instead of the Toll pathway plays a major role in DV patterning. Phylogenetic analysis of Calpains in species ranging from Isoptera to Diptera indicates an increase of Calpain sequences in the R. prolixus genome and other hemimetabolous species. One locus encoding each of the CalpC, CalpD and Calp7 families, and seven Calpain A/B loci are present in the R. prolixus genome. Several predicted R. prolixus Calpains display a unique architecture, such as loss of Calcium-binding EF-hand domains and loss of catalytic residues in the active site CysPc domain, yielding catalytically dead Calpains A/B. Knockdown for one of these inactive Calpains results in embryonic DV patterning defects, with expansion of ventral and lateral gene expression domains and consequent failure of germ band elongation. In conclusion, our results reveal that Calpains may exert a conserved function in insect DV patterning, despite the changing role of the Toll and BMP pathways in defining gene expression territories along the insect DV axis.

3.
Support Care Cancer ; 32(10): 642, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39243302

RESUMO

PURPOSE: Orbital rhabdomyosarcoma is a rare soft tissue sarcoma in childhood but with a good prognosis. Treatment usually includes surgery, chemotherapy, and radiotherapy. This study aimed to evaluate long-term alterations in teeth and cranial bones in children, adolescents, and young adults after oncologic treatment for childhood orbital rhabdomyosarcoma. METHOD: This was a cross-sectional study that evaluated patients treated for orbital rhabdomyosarcoma between 1988 and 2011. Demographic, clinical, and treatment data were collected during the study period; also, panoramic radiographs, cephalometric study, and photographs of the face were taken. RESULTS: Eight long-term survivors were studied. Of those, 50% were male, 75% had less than 5 years of treatment, and 88% had only one of the orbits affected by the tumor. Regarding treatment, 50% received 50.4 Gy of radiotherapy in the orbit; the chemotherapy included vincristine, actinomycin D, and cyclophosphamide in 75% of the cases and also ifosfamide and etoposide in 25%. The children presented craniofacial alterations, mainly when radiotherapy occurred between 0 and 5 years old (p = 0.01). The mandibles also showed dental alterations, probably due to chemotherapy. CONCLUSION: In conclusion, orbital RMS patients treated with chemoradiotherapy, important dental, and facial bone alterations were found. The most significant were in the maxilla and close to the irradiation field. Dental and mandibular bone alterations were also found, indicating the probable chemotherapy action, as this region was not included in the irradiation field.


Assuntos
Neoplasias Orbitárias , Rabdomiossarcoma , Humanos , Masculino , Feminino , Estudos Transversais , Rabdomiossarcoma/terapia , Adolescente , Neoplasias Orbitárias/terapia , Criança , Pré-Escolar , Adulto Jovem , Protocolos de Quimioterapia Combinada Antineoplásica , Quimiorradioterapia/métodos , Quimiorradioterapia/efeitos adversos , Lactente , Sobreviventes de Câncer/estatística & dados numéricos , Ciclofosfamida/administração & dosagem , Vincristina/administração & dosagem
4.
Anim Reprod ; 21(3): e20240030, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39175994

RESUMO

Selection strategies are performed post-fertilization when the random combination of paternal and maternal genomes has already occurred. It would be greatly advantageous to eliminate meiotic uncertainty by selecting genetically superior gametes before fertilization. To achieve this goal, haploid embryonic cells and embryonic stem cell lineages could be derived, genotyped, and used to substitute gametes. On the paternal side, androgenetic development can be achieved by removing the maternal chromosomes from the oocyte before or after fertilization. We have shown that once developed into an embryo, haploid cells can be removed for genotyping and, if carrying the selected genome, be used to replace sperm at fertilization. A similar strategy can be used on the maternal side by activating the oocyte parthenogenetically and using some embryonic cells for genotyping while the remaining are used to produce diploid embryos by fertilization. Placed together, both androgenetic and parthenogenetic haploid cells that have been genotyped to identify optimal genomes can be used to produce offspring with predetermined genomes. Successes and problems in developing such a breeding platform to achieve this goal are described and discussed below.

5.
Anim Reprod ; 21(3): e20240029, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39175999

RESUMO

Embryonic stem cells (ESCs) have proven to be a great in vitro model that faithfully recapitulates the events that occur during in vivo embryogenesis, making them a unique tool to study the cellular and molecular mechanisms that define tissue specification during embryonic development. Livestock ESCs are particularly attractive and have broad prospects including drug selection and human disease modeling, improvement of reproductive biotechniques and agriculture-related applications such as production of genetically modified animals. While mice and human ESCs have been established many years ago, no significant advances were made in livestock species until recently. Nowadays, livestock ESCs are available from cattle, pigs, sheep, horses and rabbits with different states of pluripotency. In this review, we summarize the current advances on livestock ESCs establishment and maintenance along with their present and future applications.

6.
Daru ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38987508

RESUMO

BACKGROUND: Several countries' most incorrectly discarded medicines are acetaminophen (ACM), metamizole (MTZ), and nimesulide (NMS). These xenobiotics easily reach the aquatic environment; such contamination is very important for the health of humans and other species, yet little explored. OBJECTIVES: To evaluate the cocktail effect of ACM, MTZ, and NMS during zebrafish's initial development. METHODS: Zebrafish embryos 6-8 h post-fertilization (hpf) were exposed to different concentrations of ACM, MTZ, and NMS, separately, to obtain the 50% lethal concentrations (LC50). Next, the embryos were exposed to distinct concentrations of the cocktail (LC50/2, LC50/5, LC50/10, and LC50/20) in a semi-static system. Samples were analyzed 0, 24, 48, and 96 h after exposure, and the drugs' concentrations in E3 medium were assessed by high-performance liquid chromatography. For embryotoxicity evaluation, the mortality, hatching, and heart rates; total length; and pericardial and yolk sac areas were determined. In addition, body malformations, edemas, presence of pigmentation, and histopathological assessments were also recorded. RESULTS: The LC50 values obtained for MTZ, ACM, and NMS were 4.69 mgmL-1, 799.98 µgmL-1, and 0.92 µgmL-1, respectively. No difference was observed between the drugs' nominal and observed concentrations at each time point. The cocktail significantly induced mortality and decreased hatching in the LC50/10, LC50/5, and LC50/2 groups. Additionally, body malformations, pigmentation loss, and yolk sac and pericardial edemas were observed in the cocktail groups. The cocktail groups' larvae had decreased total length and slower heart rates compared to the controls (p < 0.05). The histopathological assessment showed that yolk sac edema promoted severe histological changes in the esophageal-intestine junction and intestine in larvae treated with cocktails. Moreover, PAS-positive structures decreased in the esophageal-intestine junction, intestine, and liver in larvae exposed to pharmaceutical cocktails. CONCLUSION: This study's findings suggest the cocktail of ACM, MTZ, and NMS may be hazardous to aquatic organisms in case of environmental contamination.

7.
Theriogenology ; 226: 294-301, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38959839

RESUMO

Integrating in vitro embryo production with embryonic microsurgery facilitates the generation of monozygotic twins. However, despite their potential benefits, these methods have not been widely adopted in commercial settings because of their substantial costs. Hence, there is a need to streamline the bisection procedure while ensuring efficient production of viable demi-embryos. In this study, we investigated the impact of different orientations of microsurgical incisions in relation to inner cell mass on embryonic development, morphology, viability, and expression of cell fate protein markers using a simplified microsurgery approach. Ovaries were transported from the slaughterhouse to the laboratory and aspirated to obtain oocytes that were selected and subjected to in vitro embryo production. The selected expanded blastocysts (n = 204) underwent microsurgery. The blastocysts were immobilized to facilitate incision using an adapted microblade, yielding demi-embryos (vertical incision) and viable embryonic fragments (transverse incision). The structures were then re-cultured for 12 h. Viability was assessed by measuring the re-expansion rate after re-culture, followed by immunofluorescence analysis of proteins (CDX2 and NANOG) and apoptosis analysis using terminal deoxynucleotyl transferase dUTP nick end-labeling (TUNEL). Microsurgically derived embryos exhibited remarkable plasticity, as evidenced by a slight reduction (P < 0.05) in the re-expansion rate (transverse 64.2 % and vertical 57.2 %) compared to that of the control group (blastocysts without microsurgery) (86.7 %). They also demonstrated the ability of morphological reconstitution after culturing. Despite the anticipated decrease (P < 0.05) in the total number of cells and embryo volume, microsurgery did not result in a significant increase (P > 0.05) in the number of apoptotic cells. Furthermore, microsurgery led to higher (P < 0.05) expression of markers associated with pluripotency, indicating its efficiency in preserving regenerative capacity. Moreover, microsurgery, whether followed by immunosurgery or not, made the isolation of embryonic cells easier. In conclusion, both transverse and vertical microsurgery incisions enabled the production of identical demi-embryos and served as tools for isolating embryonic cells without compromising the resumption of development and the apoptotic index.


Assuntos
Técnicas de Cultura Embrionária , Microcirurgia , Animais , Microcirurgia/métodos , Microcirurgia/veterinária , Técnicas de Cultura Embrionária/veterinária , Fertilização in vitro/veterinária , Desenvolvimento Embrionário , Feminino , Embrião de Mamíferos/fisiologia , Blastocisto/fisiologia , Bovinos/embriologia
8.
Biol Res ; 57(1): 49, 2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39068496

RESUMO

BACKGROUND: The significant role of embryonic cerebrospinal fluid (eCSF) in the initial stages of brain development has been thoroughly studied. This fluid contains crucial molecules for proper brain development such as members of the Wnt and FGF families, apolipoproteins, and retinol binding protein. Nevertheless, the source of these molecules remains uncertain since they are present before the formation of the choroid plexus, which is conventionally known as the primary producer of cerebrospinal fluid. The subcommissural organ (SCO) is a highly conserved gland located in the diencephalon and is one of the earliest differentiating brain structures. The SCO secretes molecules into the eCSF, prior to the differentiation of the choroid plexus, playing a pivotal role in the homeostasis and dynamics of this fluid. One of the key molecules secreted by the SCO is SCO-spondin, a protein involved in maintenance of the normal ventricle size, straight spinal axis, neurogenesis, and axonal guidance. Furthermore, SCO secretes transthyretin and basic fibroblast growth factor 2, while other identified molecules in the eCSF could potentially be secreted by the SCO. Additionally, various transcription factors have been identified in the SCO. However, the precise mechanisms involved in the early SCO development are not fully understood. RESULTS: To uncover key molecular players and signaling pathways involved in the role of the SCO during brain development, we conducted a transcriptomic analysis comparing the embryonic chick SCO at HH23 and HH30 stages (4 and 7 days respectively). Additionally, a public transcriptomic data from HH30 entire chick brain was used to compare expression levels between SCO and whole brain transcriptome. These analyses revealed that, at both stages, the SCO differentially expresses several members of bone morphogenic proteins, Wnt and fibroblast growth factors families, diverse proteins involved in axonal guidance, neurogenic and differentiative molecules, cell receptors and transcription factors. The secretory pathway is particularly upregulated at stage HH30 while the proliferative pathway is increased at stage HH23. CONCLUSION: The results suggest that the SCO has the capacity to secrete several morphogenic molecules to the eCSF prior to the development of other structures, such as the choroid plexus.


Assuntos
Encéfalo , Perfilação da Expressão Gênica , Órgão Subcomissural , Animais , Encéfalo/metabolismo , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Órgão Subcomissural/metabolismo , Órgão Subcomissural/embriologia , Embrião de Galinha , Regulação da Expressão Gênica no Desenvolvimento
9.
Animals (Basel) ; 14(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38891667

RESUMO

The use of artificial lighting during the incubation phase is a tool that has been studied with the aim of increasing the production rates and hatchability. Using this, this study aims to investigate the effects of the luminous incidence of white and red monochromatic light on the production and metabolism of broiler chicks subjected to low temperatures. A total of 315 eggs of Ross 708 heavy breeders were used. The eggs were distributed randomly, with 35 eggs per tray, totaling 105 eggs per incubator. The treatments were the following: incubation without the use of light; the use of white monochromatic light; and the use of red monochromatic light. The lamps used were of the LED type. The samples were distributed in the factorial completely randomized experimental design with position effect on the tray. Candling, egg weighing, calculating the probability of survival and egg weight loss were performed. Temperatures were recorded using a thermographic camera. At birth, three chicks per tray were euthanized for evaluation: weight with and without yolk residue, gastrointestinal tract biometry, and blood and liver biochemistry. Analyses were performed using the R computational program. It was observed that there was a significant effect of the treatments on the levels of calcium, phosphorus, cholesterol, amylase, glucose, urea and glutamate pyruvate transaminase on the biochemical profile of the blood and on the thermographic temperatures of the eggs; the experiment was kept at low temperatures resulting in thermal stress, with an average temperature of 34.5 °C. Therefore, the use of red and white monochromatic light in the artificial incubation process for brown-colored eggs is not recommended, because in the post-hatching phase, it promoted the metabolism dysregulation on the blood biochemical profile to control the differentiation in the wavelength of traditional incubation.

10.
BioTech (Basel) ; 13(2)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38921051

RESUMO

Worldwide meat consumption and production have nearly quintupled in the last 60 years. In this context, research and the application of new technologies related to animal reproduction have evolved in an accelerated way. The objective of the present study was to apply nanoemulsions (NEs) as carriers of lipids to feed bovine embryos in culture media and verify their impact on the development of embryos produced in vitro. The NEs were characterized by particle size, polydispersity, size distribution, physical stability, morphology using atomic force microscopy (AFM), surface tension, density, pH, and rheological behavior. The NEs were prepared by the emulsification/evaporation technique. A central composite rotatable design (CCRD) was used to optimize the NE fabrication parameters. The three optimized formulations used in the embryo application showed an emulsion stability index (ESI) between 0.046 and 0.086, which reflects high stability. The mean droplet diameter analyzed by laser diffraction was approximately 70-80 nm, suggesting a possible transit across the embryonic zona pellucida with pores of an average 90 nm in diameter. AFM images clearly confirm the morphology of spherical droplets with a mean droplet diameter of less than 100 nm. The optimized formulations added during the higher embryonic genome activation phase in bovine embryos enhanced early embryonic development.

11.
Sci Total Environ ; 933: 173179, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38750761

RESUMO

Anticipating a global increase in cardiovascular diseases, there is an expected surge in the use of angiotensin-converting enzyme inhibitors, notably captopril (CAP). This heightened usage raises significant environmental apprehensions, mainly due to limited knowledge regarding CAP's toxic effects on aquatic species. In response to these concerns, the current study aimed to tackle this knowledge gap by evaluating the potential influence of nominal concentrations of CAP (0.2-2000 µg/L) on the embryonic development of Danio rerio. The findings revealed that CAP at all concentrations, even at concentrations considered environmentally significant (0.2 and 2 µg/L), induced various malformations in the embryos, ultimately leading to their mortality. Main malformations included pericardial edema, craniofacial malformation, scoliosis, tail deformation, and yolk sac deformation. In addition, CAP significantly altered the antioxidant activity of superoxide dismutase and catalase across all concentrations. Simultaneously, it elevated lipid peroxidation levels, hydroperoxides, and carbonylic proteins in the embryos, eliciting a substantial oxidative stress response. Likewise, CAP, at all concentrations, exerted significant modulatory effects on the expression of genes associated with apoptosis (bax, bcl2, p53, and casp3), organogenesis (tbx2a, tbx2b, and irx3b), and ion exchange (slc12a1 and kcnj1) in Danio rerio embryos. Both augmentation and reduction in the expression levels of these genes characterized this modulation. The Pearson correlation analysis indicated a close association between oxidative damage biomarkers and the expression patterns of all examined genes with the elevated incidence of malformations and mortality in the embryos. In summary, it can be deduced that CAP poses a threat to aquatic species. Nevertheless, further research is imperative to enhance our understanding of the environmental implications of this pharmaceutical compound.


Assuntos
Captopril , Embrião não Mamífero , Desenvolvimento Embrionário , Poluentes Químicos da Água , Peixe-Zebra , Animais , Poluentes Químicos da Água/toxicidade , Desenvolvimento Embrionário/efeitos dos fármacos , Captopril/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Inibidores da Enzima Conversora de Angiotensina/toxicidade
12.
Eur J Clin Pharmacol ; 80(8): 1121-1132, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38691138

RESUMO

PURPOSE: This systematic review aimed to determine the effects of maternal exposure to bisphosphonates (BPs) during pregnancy on neonatal outcomes. It aimed to disclosfe the impact of BPs on neonates and identify aspects that require further investigation. METHODS: A comprehensive search of PubMed, Science Direct, LILACS, EMBASE, and Web of Science was conducted until August 2022, with no time restrictions. The selection criteria included studies published in English that evaluated pregnant women who were exposed to BPs. RESULTS: From an initial pool of 2169 studies, 13 met the inclusion criteria for this systematic review. These studies collectively included 106 women (108 pregnancies) who were exposed to BPs either before orduring pregnancy. A summary of the key characteristics of the selected studies and the risk of bias assessment are provided. Exposure to BPs occurs at various stages of pregnancy, with different indications for BP treatment. The most frequently reported neonatal outcomes were spontaneous abortion, congenital malformations, hypocalcemia, preterm birth, and low birth weight. CONCLUSION: Although previous reports have linked BPs before or during pregnancy with adverse neonatal outcomes, these associations should be interpreted with caution. Given the complexity of these findings, further research is necessary to provide more definitive insights to guide clinical decisions regarding the use of BPs in pregnant women.


Assuntos
Conservadores da Densidade Óssea , Difosfonatos , Resultado da Gravidez , Humanos , Gravidez , Feminino , Difosfonatos/efeitos adversos , Difosfonatos/uso terapêutico , Difosfonatos/administração & dosagem , Recém-Nascido , Conservadores da Densidade Óssea/efeitos adversos , Conservadores da Densidade Óssea/uso terapêutico , Conservadores da Densidade Óssea/administração & dosagem , Aborto Espontâneo/induzido quimicamente , Aborto Espontâneo/epidemiologia , Complicações na Gravidez/tratamento farmacológico , Nascimento Prematuro
13.
Anim Reprod Sci ; 265: 107475, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38663149

RESUMO

A greater understanding of factors influencing fertility is essential to improve pregnancy rates and reduce the occurrence of embryonic mortality in beef herds. The objective of the current study was to evaluate retrospective data of pregnancy per artificial insemination (P/AI) and pregnancy loss in Nelore females subjected to timed-AI (TAI) in Brazil. Data from 40,104 TAI collected from six breeding seasons (2016-2022) were analyzed, and the effects of animal category (e.g., classification based on age and parity), farm, month of parturition, sire, sire breed (Nelore vs Angus), estrus expression at TAI, animal temperament, and body condition scores (BCS) were evaluated. P/AI and pregnancy loss were affected (P < 0.001) by animal category. There was also an effect of farm (P = 0.0013) on P/AI and pregnancy loss (P = 0.001), as P/AI ranged from 49.28% and 55.58% and pregnancy loss from 3.37% to 6.89% across the herds evaluated. Month of parturition also affected (P < 0.001) P/AI and was higher for cows that became pregnant at the beginning of the previous breeding season. Calmer animals, presenting lower velocity scores while exiting the chute following TAI, achieved higher P/AI (P < 0.001). Lower BCS at TAI was associated (P < 0.001) with increased pregnancy loss, and BCS gain following AI was associated (P < 0.001) with reduced rates of embryonic mortality. There was a major effect (P < 0.001) of sire on P/AI and pregnancy loss, as P/AI ranged from 11% to 79%, and embryonic mortality from 0% to 40% for the bulls used in the study, highlighting the importance of the sire fertility on overall pregnancy success. Results from the current study reinforce the idea that animal age and parity at the beginning of the breeding season, BCS at the onset of estrous synchronization, BCS gain following AI, estrus expression at TAI, sire, and month of parturition are important factors influencing P/AI and rates of embryonic mortality in beef herds.


Assuntos
Inseminação Artificial , Animais , Feminino , Gravidez , Bovinos/fisiologia , Inseminação Artificial/veterinária , Brasil , Estudos Retrospectivos , Taxa de Gravidez , Sincronização do Estro , Aborto Animal
14.
Anat Histol Embryol ; 53(3): e13038, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38563615

RESUMO

We used ultrasonography and radiography to assess the sexual organs and characterize the reproductive cycle of captive golden lancehead (Bothrops insularis) and Alcatrazes lancehead (B. alcatraz), two endangered island snake species in Brazil. We assessed 46- individuals of golden lancehead and 12 of Alcatrazes lancehead kept in captivity between 2014 and 2020. Follicular development was similar between species, but follicles in Alcatrazes lancehead were smaller than in the golden lanceheads. Female golden lanceheads produced 24 live young, seven stillborn and 73 undeveloped eggs. Parturition of live young occurred between midsummer (February) and early autumn and gestation averaged 8 months. Female Alcatrazes lanceheads produced four live young in midsummer, and one undeveloped egg in early autumn. Males and females of both species have seasonal and biennial reproductive cycles. Sperm storage in both sexes is essential to coordinate male and female cycles. The data obtained with golden lancehead and Alcatrazes lancehead in captivity, demonstrate a degree of conservatism, following data from other Bothrops.


Assuntos
Bothrops , Serpentes Peçonhentas , Viperidae , Humanos , Animais , Masculino , Feminino , Sêmen , Radiografia , Ultrassonografia/veterinária , Espécies em Perigo de Extinção
15.
Stem Cell Res Ther ; 15(1): 63, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38438875

RESUMO

BACKGROUND: Spinal ventral root avulsion results in massive motoneuron degeneration with poor prognosis and high costs. In this study, we compared different isoforms of basic fibroblast growth factor 2 (FGF2), overexpressed in stably transfected Human embryonic stem cells (hESCs), following motor root avulsion and repair with a heterologous fibrin biopolymer (HFB). METHODS: In the present work, hESCs bioengineered to overexpress 18, 23, and 31 kD isoforms of FGF2, were used in combination with reimplantation of the avulsed roots using HFB. Statistical analysis was conducted using GraphPad Prism software with one-way or two-way ANOVA, followed by Tukey's or Dunnett's multiple comparison tests. Significance was set at *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001. RESULTS: For the first set of experiments, rats underwent avulsion of the ventral roots with local administration of HFB and engraftment of hESCs expressing the above-mentioned FGF2 isoforms. Analysis of motoneuron survival, glial reaction, and synaptic coverage, two weeks after the lesion, indicated that therapy with hESCs overexpressing 31 kD FGF2 was the most effective. Consequently, the second set of experiments was performed with that isoform, so that ventral root avulsion was followed by direct spinal cord reimplantation. Motoneuron survival, glial reaction, synaptic coverage, and gene expression were analyzed 2 weeks post-lesion; while the functional recovery was evaluated by the walking track test and von Frey test for 12 weeks. We showed that engraftment of hESCs led to significant neuroprotection, coupled with immunomodulation, attenuation of astrogliosis, and preservation of inputs to the rescued motoneurons. Behaviorally, the 31 kD FGF2 - hESC therapy enhanced both motor and sensory recovery. CONCLUSION: Transgenic hESCs were an effective delivery platform for neurotrophic factors, rescuing axotomized motoneurons and modulating glial response after proximal spinal cord root injury, while the 31 kD isoform of FGF2 showed superior regenerative properties over other isoforms in addition to the significant functional recovery.


Assuntos
Células-Tronco Embrionárias , Fator 2 de Crescimento de Fibroblastos , Humanos , Animais , Ratos , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/farmacologia , Peso Molecular , Raízes Nervosas Espinhais , Biopolímeros , Fibrina , Isoformas de Proteínas/genética
16.
Perinatol. reprod. hum ; 38(1): 26-30, ene.-mar. 2024.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1569380

RESUMO

Resumen El síndrome de Turner (ST) es causado por la ausencia del segundo cromosoma sexual, dando lugar a individuos con fenotipo femenino. Se presenta en 1/2,500 recién nacidas vivas y se estima que solo el 1% de los embriones con ST logran llegar al término de su gestación. Estas pacientes presentan baja estatura, infertilidad, enfermedades cardiacas, renales y autoinmunes. Estudios han revelado alteraciones celulares y moleculares que explican la alta mortalidad en la etapa prenatal, complicaciones obstétricas y comorbilidades en estas pacientes. El objetivo de este estudio fue revisar el conocimiento actual sobre el desarrollo de embriones con ST y su impacto en la salud de las pacientes. Se consideró la literatura científica actualizada. Se han reportado diversas alteraciones celulares y moleculares en etapas prenatales en embriones con ST que impactan en la salud de estas pacientes. La comprensión de estos mecanismos nos permitirá brindar una mejor atención obstétrica que se verá reflejada hasta la vida adulta de estas.


Abstract Turner syndrome (TS) is caused by the absence of the second sex chromosome, giving rise to individuals with a female phenotype. It occurs in 1/2,500 live newborns, and it is estimated that only 1% of embryos with TS manage to reach the end of their gestation. These patients have short stature, infertility, cardiac, renal, and autoimmune diseases. Studies have revealed cellular and molecular alterations that explain the high mortality in the prenatal stage, obstetric complications, and comorbidities. The objective of this study was to review the current knowledge about the development of embryos with TS and its impact on the health of patients. The updated scientific literature was reviewed. Various cellular and molecular alterations have been reported in prenatal stages in embryos with TS, which have an impact on the health of these patients. The understanding of these mechanisms will allow us to provide better obstetric care that will be reflected until their adult life.

17.
Reprod Biomed Online ; 48(3): 103664, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38408811

RESUMO

A frequent finding after preimplantation genetic diagnostic testing for aneuploidies using next-generation sequencing is an embryo that is putatively mosaic. The prevalence of this outcome remains unclear and varies with technical and external factors. Mosaic embryos can be classified by the percentage of cells affected, type of chromosome involvement (whole or segmental), number of affected chromosomes or affected cell type (inner mass cell, trophectoderm or both). The origin of mosaicism seems to be intrinsic as a post-zygotic mitotic error, but some external factors can play a role. As experience has increased with the transfer of mosaic embryos, clinical practice has gradually become more flexible in recent years. Nevertheless, clinical results show lower implantation, pregnancy and clinical pregnancy rates and higher miscarriage rates with mosaic embryo transfer when compared with the transfer of euploid embryos. Prenatal diagnosis is highly recommended after the transfer of mosaic embryos. This narrative review is intended to serve as reference material for practitioners in reproductive medicine who must manage a mosaic embryo result after preimplantation genetic testing for aneuploidies.


Assuntos
Diagnóstico Pré-Implantação , Gravidez , Feminino , Humanos , Diagnóstico Pré-Implantação/métodos , Testes Genéticos/métodos , Implantação do Embrião , Aneuploidia , Mosaicismo , Blastocisto/metabolismo
18.
JBRA Assist Reprod ; 28(2): 263-268, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38381778

RESUMO

OBJECTIVE: The objective of this research is to investigate the association between the concentrations of soluble human leukocyte G antigen (sHLA-G) in the follicular fluid (FF) in infertile patients with peritoneal endometriosis submitted to in vitro fertilization. METHODS: We performed a cross-sectional study, including ninety-six women undergoing in vitro fertilization (IVF) ageing ≤ 40 years. Infertile patients were classified into two groups: with endometriosis diagnosed by laparoscopy and without endometriosis due to tubal factor. ELISA measured soluble HLA-G in the FF of a pool of punctured (more than 17mm) follicles from women with endometriosis and without endometriosis who were subjected to ovulation induction for IVF. Embryos obtained after fertilization were classified according to the graduated embryo score (GES). RESULTS: Groups were comparables in terms of age, the number of follicles, AMH, FSH and all included reproductive outcomes. There was no association between sHLA-G concentrations and the average score of the generated embryos (p>0.05). Measurement of sHLA-G in the follicle fluid in women with endometriosis and without endometriosis (tubal factor) showed no significant difference (p>0.05). We also compared sHLA-G per follicle and per embryo, which were not different between both groups (p>0.05). CONCLUSIONS: Patients with peritoneal endometriosis submitted to IVF did not demonstrate an altered sHLA-G in the follicular fluid compared to the follicular fluid sHLA-G concentration in tubal factor patients. Also, this molecule was not linked to any other reproductive outcome.


Assuntos
Endometriose , Fertilização in vitro , Líquido Folicular , Antígenos HLA-G , Infertilidade Feminina , Humanos , Feminino , Endometriose/metabolismo , Líquido Folicular/metabolismo , Líquido Folicular/química , Adulto , Antígenos HLA-G/metabolismo , Antígenos HLA-G/análise , Estudos Transversais , Infertilidade Feminina/metabolismo , Gravidez
19.
Front Mol Biosci ; 11: 1336336, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38380430

RESUMO

Alternative polyadenylation (APA) increases transcript diversity through the generation of isoforms with varying 3' untranslated region (3' UTR) lengths. As the 3' UTR harbors regulatory element target sites, such as miRNAs or RNA-binding proteins, changes in this region can impact post-transcriptional regulation and translation. Moreover, the APA landscape can change based on the cell type, cell state, or condition. Given that APA events can impact protein expression, investigating translational control is crucial for comprehending the overall cellular regulation process. Revisiting data from polysome profiling followed by RNA sequencing, we investigated the cardiomyogenic differentiation of pluripotent stem cells by identifying the transcripts that show dynamic 3' UTR lengthening or shortening, which are being actively recruited to ribosome complexes. Our findings indicate that dynamic 3' UTR lengthening is not exclusively associated with differential expression during cardiomyogenesis but rather with recruitment to polysomes. We confirm that the differentiated state of cardiomyocytes shows a preference for shorter 3' UTR in comparison to the pluripotent stage although preferences vary during the days of the differentiation process. The most distinct regulatory changes are seen in day 4 of differentiation, which is the mesoderm commitment time point of cardiomyogenesis. After identifying the miRNAs that would target specifically the alternative 3' UTR region of the isoforms, we constructed a gene regulatory network for the cardiomyogenesis process, in which genes related to the cell cycle were identified. Altogether, our work sheds light on the regulation and dynamic 3' UTR changes of polysome-recruited transcripts that take place during the cardiomyogenic differentiation of pluripotent stem cells.

20.
Int. j. morphol ; 42(1): 21-27, feb. 2024. ilus
Artigo em Espanhol | LILACS | ID: biblio-1528821

RESUMO

El cobayo es un modelo animal ampliamente utilizado en la investigación biomédica debido a sus similitudes biológicas con los seres humanos. El objetivo de nuestro estudio es proporcionar sustento morfológico para utilizar preparados histológicos de embriones de cobayo como modelo de estudio para comprender los procesos del desarrollo embrionario humano. Nuestros resultados muestran que los embriones de cobayo presentan características morfológicas similares a las observadas en los embriones humanos, lo que sugiere que pueden utilizarse como un modelo efectivo para estudiar el desarrollo embrionario humano. Este hallazgo tiene importantes implicancias para la investigación y la docencia utilizando este modelo animal. Se analizaron preparados histológicos de embriones de cobayo teñidos con hematoxilina eosina, adquiridos por la Universidad Autónoma de Chile. Se tomaron microfotografías de preparados histológicos de cobayo en diferentes estadios del desarrollo y se seleccionaron las mejores imágenes para la descripción de estructuras y establecer estimados de la embriogénesis. Del análisis de los preparados se desprende que órganos como esófago, médula espinal y corazón presentan similitudes anatómicas e histológicas que hacen posible compararlas con el desarrollo embrionario humano y la edad de gestación en etapas tempranas. El uso de preparados de embriones de cobayo y su análisis desde un aspecto histológico resulta ser una estrategia metodológica factible debido a las similitudes en la embriogénesis de los mamíferos y las concordancias morfológicas con el desarrollo de los órganos entre humanos y roedores. Esto permite implementar este modelo animal como una herramienta para comprender el desarrollo embrionario humano.


SUMMARY: The guinea pig is an animal model widely used in biomedical research due to its biological similarities with humans. The objective of our study is to provide morphological support to use histological preparations of guinea pig embryos as a study model to understand the processes of human embryonic development. Our results show that guinea pig embryos present morphological characteristics similar to those observed in human embryos, suggesting that they can be used as an effective model to study human embryonic development. This finding has important implications for research and teaching using this animal model. Histological preparations of guinea pig embryos stained with hematoxylin eosin, acquired by the Autonomous University of Chile, were analyzed. Photomicrographs of histological preparations of guinea pigs at different stages of development were taken and the best images were selected to describe structures and establish estimates of embryogenesis. From the analysis of the preparations it is clear that organs such as the esophagus, spinal cord and heart present anatomical and histological similarities that make it possible to compare them with human embryonic development and gestation age in early stages. The use of guinea pig embryo preparations and their analysis from a histological aspect turns out to be a feasible methodological strategy due to the similarities in mammalian embryogenesis and the morphological concordances with the development of organs between humans and rodents. This allows this animal model to be implemented as a tool to understand human embryonic development.


Assuntos
Humanos , Animais , Cobaias , Desenvolvimento Embrionário , Embrião de Mamíferos/anatomia & histologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA