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1.
Semin Cell Dev Biol ; 138: 28-35, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35787974

RESUMO

The neural crest is a vertebrate-specific embryonic stem cell population that gives rise to a vast array of cell types throughout the animal body plan. These cells are first born at the edges of the central nervous system, from which they migrate extensively and differentiate into multiple cellular derivatives. Given the unique set of structures these cells comprise, the origin of the neural crest is thought to have important implications for the evolution and diversification of the vertebrate clade. In jawed vertebrates, neural crest cells exist as distinct subpopulations along the anterior-posterior axis. These subpopulations differ in terms of their respective differentiation potential and cellular derivatives. Thus, the modern neural crest is characterized as multipotent, migratory, and regionally segregated throughout the embryo. Here, we retrace the evolutionary origins of the neural crest, from the appearance of conserved regulatory circuitry in basal chordates to the emergence of neural crest subpopulations in higher vertebrates. Finally, we discuss a stepwise trajectory by which these cells may have arisen and diversified throughout vertebrate evolution.


Assuntos
Evolução Biológica , Crista Neural , Animais , Vertebrados/genética , Diferenciação Celular/fisiologia
2.
Mol Psychiatry ; 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38514804

RESUMO

Bridging Integrator 1 (BIN1) is the second most important Alzheimer's disease (AD) risk gene, but its physiological roles in neurons and its contribution to brain pathology remain largely elusive. In this work, we show that BIN1 plays a critical role in the regulation of calcium homeostasis, electrical activity, and gene expression of glutamatergic neurons. Using single-cell RNA-sequencing on cerebral organoids generated from isogenic BIN1 wild type (WT), heterozygous (HET) and homozygous knockout (KO) human-induced pluripotent stem cells (hiPSCs), we show that BIN1 is mainly expressed by oligodendrocytes and glutamatergic neurons, like in the human brain. Both BIN1 HET and KO cerebral organoids show specific transcriptional alterations, mainly associated with ion transport and synapses in glutamatergic neurons. We then demonstrate that BIN1 cell-autonomously regulates gene expression in glutamatergic neurons by using a novel protocol to generate pure culture of hiPSC-derived induced neurons (hiNs). Using this system, we also show that BIN1 plays a key role in the regulation of neuronal calcium transients and electrical activity via its interaction with the L-type voltage-gated calcium channel Cav1.2. BIN1 KO hiNs show reduced activity-dependent internalization and higher Cav1.2 expression compared to WT hiNs. Pharmacological blocking of this channel with clinically relevant doses of nifedipine, a calcium channel blocker, partly rescues electrical and gene expression alterations in BIN1 KO glutamatergic neurons. Further, we show that transcriptional alterations in BIN1 KO hiNs that affect biological processes related to calcium homeostasis are also present in glutamatergic neurons of the human brain at late stages of AD pathology. Together, these findings suggest that BIN1-dependent alterations in neuronal properties could contribute to AD pathophysiology and that treatment with low doses of clinically approved calcium blockers should be considered as an option to slow disease-onset and progression.

3.
Nature ; 574(7780): 675-678, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645763

RESUMO

The neural crest, an embryonic stem-cell population, is a vertebrate innovation that has been proposed to be a key component of the 'new head', which imbued vertebrates with predatory behaviour1,2. Here, to investigate how the evolution of neural crest cells affected the vertebrate body plan, we examined the molecular circuits that control neural crest development along the anteroposterior axis of a jawless vertebrate, the sea lamprey. Gene expression analysis showed that the cranial subpopulation of the neural crest of the lamprey lacks most components of a transcriptional circuit that is specific to the cranial neural crest in amniotes and confers the ability to form craniofacial cartilage onto non-cranial neural crest subpopulations3. Consistent with this, hierarchical clustering analysis revealed that the transcriptional profile of the lamprey cranial neural crest is more similar to the trunk neural crest of amniotes. Notably, analysis of the cranial neural crest in little skate and zebrafish embryos demonstrated that the transcriptional circuit that is specific to the cranial neural crest emerged via the gradual addition of network components to the neural crest of gnathostomes, which subsequently became restricted to the cephalic region. Our results indicate that the ancestral neural crest at the base of the vertebrate lineage possessed a trunk-like identity. We propose that the emergence of the cranial neural crest, by progressive assembly of an axial-specific regulatory circuit, allowed the elaboration of the new head during vertebrate evolution.


Assuntos
Evolução Biológica , Padronização Corporal , Cabeça , Crista Neural , Animais , Regulação da Expressão Gênica no Desenvolvimento , Cabeça/fisiologia , Lampreias/embriologia , Crista Neural/embriologia , Crista Neural/fisiologia , Crânio/embriologia , Peixe-Zebra/embriologia , Peixe-Zebra/genética
4.
Development ; 148(16)2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34351428

RESUMO

Neocortical progenitor cells generate subtypes of excitatory projection neurons in sequential order followed by the generation of astrocytes. The transcription factor zinc finger and BTB domain-containing protein 20 (ZBTB20) has been implicated in regulation of cell specification during neocortical development. Here, we show that ZBTB20 instructs the generation of a subset of callosal projections neurons in cortical layers II/III in mouse. Conditional deletion of Zbtb20 in cortical progenitors, and to a lesser degree in differentiating neurons, leads to an increase in the number of layer IV neurons at the expense of layer II/III neurons. Astrogliogenesis is also affected in the mutants with an increase in the number of a specific subset of astrocytes expressing GFAP. Astrogliogenesis is more severely disrupted by a ZBTB20 protein containing dominant mutations linked to Primrose syndrome, suggesting that ZBTB20 acts in concert with other ZBTB proteins that were also affected by the dominant-negative protein to instruct astrogliogenesis. Overall, our data suggest that ZBTB20 acts both in progenitors and in postmitotic cells to regulate cell fate specification in the mammalian neocortex.


Assuntos
Astrócitos/metabolismo , Neocórtex/crescimento & desenvolvimento , Neurogênese/genética , Neurônios/metabolismo , Fatores de Transcrição/metabolismo , Anormalidades Múltiplas/genética , Animais , Calcinose/genética , Otopatias/genética , Feminino , Técnicas de Inativação de Genes , Deficiência Intelectual/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atrofia Muscular/genética , Mutação de Sentido Incorreto , Neocórtex/metabolismo , Transdução de Sinais/genética , Células-Tronco/metabolismo , Fatores de Transcrição/genética
5.
Childs Nerv Syst ; 40(4): 1213-1219, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38157046

RESUMO

PURPOSE: The management of depressed skull fractures in infants can be either conservative or surgical. This study aimed to examine the outcomes of management with a negative-pressure vacuum device on depressed skull fractures in newborns. METHODS: Twenty-eight patients (aged 1-6 days) with simple depressed skull fractures underwent skull elevation using negative-pressure vacuum devices. A protocol for nonsurgical management was adopted for infants with such fractures between 2010 and 2023. All patients were initially evaluated with neurological examination and complementary assessments-hematological and coagulation studies, transfontanel transcranial ultrasound, skull radiography, and computed tomography scanning with three-dimensional reconstruction-according to availability and clinical needs. Gentle (negative) extraction pressure was applied with one of several devices (according to institutional availability) for a maximum duration of 60 s; this was performed as soon as possible after diagnosis, preferably within 72 h. Follow-up data, available in the clinical records, were reported. RESULTS: All patients exhibited satisfactory elevation of the depressed bone without associated injuries, except one patient who presented with an associated cephalohematoma which prevented optimal device coupling to generate sufficient vacuum pressure for correction. Neither neurological deficits nor development of epilepsy was noted; normal neurological assessment and oral alimentation tolerance were confirmed within 24 h post procedure. CONCLUSIONS: According to our data, ping-pong skull fracture elevation using the vacuum method is a safe and satisfactory treatment in the neonatal period. Early treatment allows for quick resolution, and in our opinion is the strategy of choice for depressed skull fractures in newborns.


Assuntos
Fratura do Crânio com Afundamento , Fraturas Cranianas , Lactente , Humanos , Recém-Nascido , Vácuo , Crânio , Cabeça
6.
PLoS Genet ; 17(1): e1009296, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33465092

RESUMO

The process of cell fate commitment involves sequential changes in the gene expression profiles of embryonic progenitors. This is exemplified in the development of the neural crest, a migratory stem cell population derived from the ectoderm of vertebrate embryos. During neural crest formation, cells transition through distinct transcriptional states in a stepwise manner. The mechanisms underpinning these shifts in cell identity are still poorly understood. Here we employ enhancer analysis to identify a genetic sub-circuit that controls developmental transitions in the nascent neural crest. This sub-circuit links Wnt target genes in an incoherent feedforward loop that controls the sequential activation of genes in the neural crest lineage. By examining the cis-regulatory apparatus of Wnt effector gene AXUD1, we found that multipotency factor SP5 directly promotes neural plate border identity, while inhibiting premature expression of specification genes. Our results highlight the importance of repressive interactions in the neural crest gene regulatory network and illustrate how genes activated by the same upstream signal become temporally segregated during progressive fate restriction.


Assuntos
Elementos Facilitadores Genéticos/genética , Crista Neural/crescimento & desenvolvimento , Placa Neural/crescimento & desenvolvimento , Fatores de Transcrição/genética , Animais , Proteínas Reguladoras de Apoptose/genética , Diferenciação Celular/genética , Movimento Celular/genética , Embrião de Galinha , Proteínas de Ligação a DNA/genética , Ectoderma/crescimento & desenvolvimento , Transição Epitelial-Mesenquimal/genética , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes/genética , Humanos , Hibridização In Situ , Crista Neural/metabolismo , Placa Neural/metabolismo , Via de Sinalização Wnt/genética
7.
Genome Res ; 30(1): 35-48, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31848212

RESUMO

Cell fate commitment involves the progressive restriction of developmental potential. Recent studies have shown that this process requires not only shifts in gene expression but also an extensive remodeling of the epigenomic landscape. To examine how chromatin states are reorganized during cellular specification in an in vivo system, we examined the function of pioneer factor TFAP2A at discrete stages of neural crest development. Our results show that TFAP2A activates distinct sets of genomic regions during induction of the neural plate border and specification of neural crest cells. Genomic occupancy analysis revealed that the repertoire of TFAP2A targets depends upon its dimerization with paralogous proteins TFAP2C and TFAP2B. During gastrula stages, TFAP2A/C heterodimers activate components of the neural plate border induction program. As neurulation begins, TFAP2A trades partners, and TFAP2A/B heterodimers reorganize the epigenomic landscape of progenitor cells to promote neural crest specification. We propose that this molecular switch acts to drive progressive cell commitment, remodeling the epigenomic landscape to define the presumptive neural crest. Our findings show how pioneer factors regulate distinct genomic targets in a stage-specific manner and highlight how paralogy can serve as an evolutionary strategy to diversify the function of the regulators that control embryonic development.


Assuntos
Desenvolvimento Embrionário/genética , Epigênese Genética , Crista Neural/embriologia , Crista Neural/metabolismo , Multimerização Proteica , Fator de Transcrição AP-2/genética , Fator de Transcrição AP-2/metabolismo , Animais , Diferenciação Celular , Embrião de Galinha , Epigenômica , Imunofluorescência , Regulação da Expressão Gênica no Desenvolvimento , Imuno-Histoquímica , Sequências Reguladoras de Ácido Nucleico , Fator de Transcrição AP-2/química
8.
Pediatr Blood Cancer ; 70(11): e28493, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-32790146

RESUMO

Pediatric craniopharyngioma is a rare tumor with excellent survival but significant long-term morbidities due to the loco-regional tumor growth or secondary to its treatment. Visual impairment, panhypopituitarism, hypothalamic damage, and behavioral changes are among the main challenges. This tumor should be managed under the care of a multidisciplinary team to determine the optimum treatment within the available resources. This is particularly important for low middle-income countries where resources are variable. This report provides risk-stratified management guidelines for children diagnosed with craniopharyngioma in a resource-limited setting.


Assuntos
Craniofaringioma , Hipopituitarismo , Neoplasias Hipofisárias , Criança , Humanos , Craniofaringioma/terapia , Renda , Gestão de Riscos , Neoplasias Hipofisárias/terapia
9.
Plant Cell Rep ; 42(1): 137-152, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36348064

RESUMO

KEY MESSAGE: The overexpression of the soybean GmEXPA1 gene reduces plant susceptibility to M. incognita by the increase of root lignification. Plant expansins are enzymes that act in a pH-dependent manner in the plant cell wall loosening and are associated with improved tolerance or resistance to abiotic or biotic stresses. Plant-parasitic nematodes (PPN) can alter the expression profile of several expansin genes in infected root cells. Studies have shown that overexpression or downregulation of particular expansin genes can reduce plant susceptibility to PPNs. Root-knot nematodes (RKN) are obligate sedentary endoparasites of the genus Meloidogyne spp. of which M. incognita is one of the most reported species. Herein, using a transcriptome dataset and real-time PCR assays were identified an expansin A gene (GmEXPA1; Glyma.02G109100) that is upregulated in the soybean nematode-resistant genotype PI595099 compared to the susceptible cultivar BRS133 during plant parasitism by M. incognita. To understand the role of the GmEXPA1 gene during the interaction between soybean plant and M. incognita were generated stable A. thaliana and N. tabacum transgenic lines. Remarkably, both A. thaliana and N. tabacum transgenic lines overexpressing the GmEXPA1 gene showed reduced susceptibility to M. incognita. Furthermore, plant growth, biomass accumulation, and seed yield were not affected in these transgenic lines. Interestingly, significant upregulation of the NtACC oxidase and NtEFE26 genes, involved in ethylene biosynthesis, and NtCCR and Nt4CL genes, involved in lignin biosynthesis, was observed in roots of the N. tabacum transgenic lines, which also showed higher lignin content. These data suggested a possible link between GmEXPA1 gene expression and increased lignification of the root cell wall. Therefore, these data support that engineering of the GmEXPA1 gene in soybean offers a powerful biotechnology tool to assist in RKN management.


Assuntos
Arabidopsis , Tylenchoidea , Animais , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Tylenchoidea/genética , Arabidopsis/genética , Lignina , Transcriptoma
10.
Childs Nerv Syst ; 39(6): 1647-1651, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36705687

RESUMO

INTRODUCTION: This study aimed to highlight that atlantoaxial rotatory fixation (AARF) can be related to neurosurgery procedures in children, with an afterward demonstration of good results after halo-gravity traction and C1-C2 stabilization using the Harms technique. CASE DESCRIPTION: To the best of our knowledge, this is the first case to report a 4-year-old boy who presented with AARF after a posterior fossa craniotomy to treat a cerebellar astrocytoma. At our medical facility, AARF was diagnosed using plain radiography and computed tomography imaging. The patient was treated with continuous cranial traction for 14 days. Initially, we detected that the patient had no C1 posterior arch or C2 spinous process; therefore, the best option was to perform the Harms technique. Postoperatively, the patient was placed in a cervical collar for 4 weeks. At the 4-year postoperative follow-up, the patient was doing well and had not developed any complications. CONCLUSION: Herein, we report a case in which AARF can be developed after neurosurgical procedure. Surgical techniques used for atlantoaxial subluxation should be carefully selected. In our case, the Harms technique after cranial traction was an excellent option for correcting and stabilizing the abnormal neck position. However, further studies are required to determine the best technique to use in the pediatric population.


Assuntos
Articulação Atlantoaxial , Luxações Articulares , Masculino , Humanos , Criança , Pré-Escolar , Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/cirurgia , Luxações Articulares/complicações , Radiografia , Tomografia Computadorizada por Raios X , Craniotomia
11.
Childs Nerv Syst ; 39(2): 481-489, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36258049

RESUMO

Schistosomiasis is an endemic parasitic disease in several tropical countries. In Brazil, the only prevalent species of parasite responsible for schistosomiasis is Schistosoma mansoni. Neuroschistosomiasis is the second most frequent form of infection and the primary ectopic manifestation, with predominant involvement of the lower thoracic spinal cord and lumbar and lumbosacral regions. The frequent contact of children with contaminated ponds and the immaturity of their immune systems make this age group especially susceptible to infection by this parasite. Therefore, neuroschistosomiasis mansoni should always be considered in cases of transverse myelitis in children from endemic regions. The treatment for this condition is quite simple and effective, resulting in total recovery of neurological deficits if the diagnosis is made early.


Assuntos
Neuroesquistossomose , Doenças da Medula Espinal , Animais , Criança , Humanos , Neuroesquistossomose/diagnóstico , Neuroesquistossomose/parasitologia , Neuroesquistossomose/patologia , Schistosoma mansoni , Doenças da Medula Espinal/diagnóstico , Brasil
12.
Childs Nerv Syst ; 39(9): 2329-2339, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37202535

RESUMO

PURPOSE: This study aimed to identify factors of a worse prognosis among different histological types of pineal region tumors in pediatric patients treat at a single institution in a 30-year period. MATERIAL AND METHODS: Pediatric patients (151; < 18 years of age) treated between 1991 and 2020 were analyzed. Kaplan-Meyer survival curves were created, and the log-rank test was used to compare the main prognostic factors in the different histological types. RESULTS: Germinoma was found in 33.1%, with an overall 60-month survival rate of 88%; the female sex was the only factor of a worse prognosis. Non-germinomatous germ cell tumors were found in 27.1%, with an overall 60-month survival rate of 67.2%; metastasis upon diagnosis, residual tumor, and the absence of radiotherapy were associated with a worse diagnosis. Pineoblastoma was found in 22.5%, with an overall 60-month survival rate of 40.7%; the male sex was the only factor of a worse prognosis; a tendency toward a worse outcome was found in patients < 3 years of age and those with metastasis upon diagnosis. Glioma was identified in 12.5%, with an overall 60-month survival rate of 72.6%; high-grade gliomas were associated with a worse prognosis. Atypical teratoid rhabdoid tumors was found in 3.3%, and all patients died within a 19-month period. CONCLUSION: Pineal region tumors are characterized by the heterogeneity of histological types, which exert an influence on the outcome. Knowledge of the prognostic factors for each histological types is of extreme importance to the determination of guided multidisciplinary treatment.


Assuntos
Neoplasias Encefálicas , Glioma , Glândula Pineal , Pinealoma , Criança , Humanos , Masculino , Feminino , Pinealoma/cirurgia , Prognóstico , Glândula Pineal/cirurgia , Neoplasias Encefálicas/cirurgia , Glioma/patologia
13.
Childs Nerv Syst ; 39(12): 3361-3369, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37878057

RESUMO

PURPOSE: The study aimed to summarize all published cases of intrinsic brainstem epidermoid cysts in a timeline to highlight the specific characteristics and individualize the disease, in addition to discussing the best treatment used. METHODS: The scientific literature on pediatric cases of intrinsic epidermoid cysts of the brainstem was analyzed. We present the case of a 1.5-year-old male with incidental presentation, who was treated with gross total resection. We summarize all previously published cases to individualize the disease. RESULTS: We identified 21 patients, including 10 boys and 11 girls, with a mean age of 4.85 (1-15) years at the time of surgery. The most frequent symptoms were cranial nerve palsy (71.4%), pyramidal tract deficit (57.14%), and headache (52.38%). Among the affected cranial nerves, VII was the most frequently reported in 10 patients. CONCLUSION: Brainstem epidermoid cysts are extremely rare pathologies with relevant age involvement in young children. The treatment objective should be the maximum resection of the lesion through a careful approach and with the appropriate tools for the functional preservation of the patient.


Assuntos
Cisto Epidérmico , Masculino , Feminino , Humanos , Criança , Pré-Escolar , Lactente , Cisto Epidérmico/diagnóstico por imagem , Cisto Epidérmico/cirurgia , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/cirurgia , Tronco Encefálico/patologia , Nervos Cranianos
14.
Childs Nerv Syst ; 39(6): 1485-1493, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36454311

RESUMO

PURPOSE: Low-grade gliomas compose 30% of pediatric central nervous system tumors and outcomes of disease-free progression, and survival is directly correlated to the extent of resection. The use of sodium fluorescein (Na-Fl) is an intraoperative method in the localization of tumor cells in adult patients to optimize resection. Our purpose is to describe the use of Na-Fl in pediatric low-grade gliomas and its outcomes. METHODS: Patients under 18 years of age with low-grade gliomas at the author's institution underwent resection with the use of Na-Fl, with review of preoperative imaging findings, intraoperative results, and follow-up. Then, a comprehensive, narrative literature review of the use of Na-Fl in pediatric low-grade glioma was performed. RESULTS: Our single-institution use of Na-Fl in pediatric patients with suspected low-grade glioma demonstrated excellent results of intraoperative enhancement of tumor cells as well as gross total resection. The literature demonstrated 84% Na-Fl staining and 59.2% of gross total resection in pediatric low-grade gliomas with few small case studies, a range of reported findings, and few side effects. CONCLUSION: Na-Fl has a promising use in low-grade glioma resection in the pediatric patient population. Further research is warranted, such as randomized controlled studies, to assess Na-Fl as a potential tool in improving resection and long-term favorable outcomes.


Assuntos
Neoplasias Encefálicas , Glioma , Adulto , Humanos , Criança , Adolescente , Fluoresceína , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/patologia , Glioma/diagnóstico por imagem , Glioma/cirurgia , Glioma/patologia , Procedimentos Neurocirúrgicos/métodos
15.
Childs Nerv Syst ; 39(7): 1881-1887, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36715744

RESUMO

PURPOSE: The possibility that ventricular opening generates postoperative complications after surgical tumor treatment often restricts the degree of tumor resection. This study aims to determine whether the ventricular opening is associated with more complications in surgeries for resectioning supratentorial intra-axial brain tumors in the pediatric population. METHODS: A retrospective review analysis was performed of patients treated at IOP/GRAACC between 2002 and 2020 under 19 years of age and underwent surgery for supratentorial intra-axial primary brain tumor resection. Data were collected from 43 patients. RESULTS: Glial tumor was more common than non-glial (65% vs. 35%, p = 0.09). The ventricular opening was not related to neoplastic spreads to the neuroaxis (6% vs. 0, p > 0.9) or leptomeningeal (3% vs. 0, p > 0.9). Of the patients whose ventricle was opened, 10% developed hydrocephalus requiring treatment, while none of the patients in the group without ventricular opening developed hydrocephalus (p = 0.5). There was also no statistical difference regarding ventriculitis. Postoperative subdural hygroma formation correlated with the ventricular opening (43% vs. 0, p = 0.003). The survival at 1, 5, and 10 years of cases with the ventricular opening was 93.2%, 89.7%, and 75.7%, respectively, while in cases without ventricular opening, it was 100%, 83%, and 83%, respectively, respectively, with no statistical difference between the mortality curves. CONCLUSION: Our study demonstrated that ventricular violation was not associated with the occurrence of significant complications. It was related to the formation of subdural hygroma, which did not require additional treatment.


Assuntos
Neoplasias Encefálicas , Hidrocefalia , Linfangioma Cístico , Derrame Subdural , Neoplasias Supratentoriais , Humanos , Criança , Derrame Subdural/complicações , Linfangioma Cístico/complicações , Resultado do Tratamento , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Neoplasias Supratentoriais/cirurgia , Estudos Retrospectivos , Hidrocefalia/etiologia , Hidrocefalia/cirurgia , Neoplasias Encefálicas/cirurgia
16.
Childs Nerv Syst ; 39(11): 3131-3136, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-36840750

RESUMO

PURPOSE: The recent history of myelomeningocele has shown that treatment during the fetal life may reduce the risk of developing hydrocephalus in individuals by approximately 50%. Thus, a significant advancement involves fetal surgery performed through an endoscopic technique in which portals are placed to introduce the forceps and laparoscopic instruments. However, the development of this technique requires training; therefore, this study aimed to develop a training model for fetal myelomeningocele repair technique with multi-portal endoscopy. METHODS: Two stages of endoscopic technique development were performed. The first stage consisted of exercises in order to familiarize the surgeon with 2D-vision endoscopic surgery, associated with the application of exercises focused on surgical skills, such as the development of laparoscopic knots in a synthetic model. The second stage involved the creation and application of the stages of myelomeningocele closure with a non-living animal model consisting of a chicken breast to simulate the myelomeningocele and a basketball to simulate the gravid uterus, in which perforations were made to introduce vascular introducers (portals) that, as in vivo, are used as portals (trocars) for the introduction of laparoscopic instruments. Overall, two different scenarios with three portals and two portals were tested. RESULTS: In three-portal simulator, the triangular apex trocar was used for the introduction of 4-mm 0° or 30° optics or even Minop type neurodoscope (Aesculap®, Germany) that was operated by the assistant surgeon; the other two portals are used for the introduction of laparoscopic instruments. Thus, the surgeon is able to perform maneuvers bimanually since dissection to laparoscopic sutures. In two-portal simulator, the surgeon and assistant stay side by side and one of the portals is used for the optic and the other for the laparoscopic instruments. There is no possibility of bimanual dissection in this method. CONCLUSION: Realistic simulation models for endoscopic fetal surgery for myelomeningocele correction are easily performed and help develop the necessary skills for fetal surgery teams.


Assuntos
Hidrocefalia , Laparoscopia , Meningomielocele , Humanos , Gravidez , Feminino , Animais , Meningomielocele/cirurgia , Feto/cirurgia , Cuidado Pré-Natal , Hidrocefalia/cirurgia
17.
Childs Nerv Syst ; 39(10): 2899-2927, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37606832

RESUMO

Among fetal surgical procedures, neurosurgery stands out due to the number of cases and the possibility of developing new procedures that can be performed in the fetal period. To perform fetal neurosurgical procedures, there is a need for specialized centers that have experts in the diagnosis of fetal pathologies and a highly complex obstetrics service with specialized maternal-fetal teams associated with a pediatric neurosurgery center with expertise in the diverse pathologies of the fetus and the central nervous system that offers multidisciplinary follow-up during postnatal life. Services that do not have these characteristics should refer their patients to these centers to obtain better treatment results. It is essential that the fetal neurosurgical procedure be performed by a pediatric neurosurgeon with extensive experience, as he will be responsible for monitoring these patients in the postnatal period and for several years. The objective of this manuscript is to demonstrate the diagnostic and treatment possibilities, in the fetal period, of some neurosurgical diseases such as hydrocephalus, tumors, occipital encephalocele, and myelomeningocele.


Assuntos
Hidrocefalia , Meningomielocele , Neurocirurgia , Masculino , Gravidez , Feminino , Humanos , Criança , Feto/cirurgia , Procedimentos Neurocirúrgicos/métodos , Hidrocefalia/cirurgia , Meningomielocele/cirurgia , Meningomielocele/complicações
18.
Proc Natl Acad Sci U S A ; 117(52): 33305-33316, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33376218

RESUMO

Ectodermal patterning is required for the establishment of multiple components of the vertebrate body plan. Previous studies have demonstrated that precise combinations of extracellular signals induce distinct ectodermal cell populations, such as the neural crest and the neural plate. Yet, we still lack understanding of how the response to inductive signals is modulated to generate the proper transcriptional output in target cells. Here we show that posttranscriptional attenuation of fibroblast growth factor (FGF) signaling is essential for the establishment of the neural crest territory. We found that neural crest progenitors display elevated expression of DICER, which promotes enhanced maturation of a set of cell-type-specific miRNAs. These miRNAs collectively target components of the FGF signaling pathway, a central player in the process of neural induction in amniotes. Inactivation of this posttranscriptional circuit results in a fate switch, in which neural crest cells are converted into progenitors of the central nervous system. Thus, the posttranscriptional attenuation of signaling systems is a prerequisite for proper segregation of ectodermal cell types. These findings demonstrate how posttranscriptional repression may alter the activity of signaling systems to generate distinct spatial domains of progenitor cells.


Assuntos
Fatores de Crescimento de Fibroblastos/genética , Crista Neural/metabolismo , Transdução de Sinais , Transcrição Gênica , Animais , Linhagem da Célula , Embrião de Galinha , Ectoderma/citologia , Fatores de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos , Crista Neural/citologia , Ribonuclease III/metabolismo , Transdução de Sinais/genética , Células-Tronco/citologia , Células-Tronco/metabolismo
19.
J Anim Breed Genet ; 140(1): 1-12, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36239216

RESUMO

This study was carried out to evaluate the advantage of preselecting SNP markers using Markov blanket algorithm regarding the accuracy of genomic prediction for carcass and meat quality traits in Nellore cattle. This study considered 3675, 3680, 3660 and 524 records of rib eye area (REA), back fat thickness (BF), rump fat (RF), and Warner-Bratzler shear force (WBSF), respectively, from the Nellore Brazil Breeding Program. The animals have been genotyped using low-density SNP panel (30 k), and subsequently imputed for arrays with 777 k SNPs. Four Bayesian specifications of genomic regression models, namely Bayes A, Bayes B, Bayes Cπ and Bayesian Ridge Regression methods were compared in terms of prediction accuracy using a five folds cross-validation. Prediction accuracy for REA, BF and RF was all similar using the Bayesian Alphabet models, ranging from 0.75 to 0.95. For WBSF, the predictive ability was higher using Bayes B (0.47) than other methods (0.39 to 0.42). Although the prediction accuracies using Markov blanket of SNP markers were lower than those using all SNPs, for WBSF the relative gain was lower than 13%. With a subset of informative SNPs markers, identified using Markov blanket, probably, is possible to capture a large proportion of the genetic variance for WBSF. The development of low-density and customized arrays using Markov blanket might be cost-effective to perform a genomic selection for this trait, increasing the number of evaluated animals, improving the management decisions based on genomic information and applying genomic selection on a large scale.


Assuntos
Genômica , Bovinos/genética , Animais , Teorema de Bayes , Brasil
20.
Trop Anim Health Prod ; 55(4): 243, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37337066

RESUMO

Little is known about the performance, carcass, and meat traits of locally adapted cattle in Brazil. This study aimed to compare the growth, slaughter, and carcass traits as well as meat quality of two local breeds (Curraleiro Pé-Duro and Pantaneiro) with the Nelore breed. Fifteen 30-month-old steers of each breed were weighted (Curraleiro Pé-Duro = 264.80 kg; Nelore = 346.80 kg; Pantaneiro = 316.20 kg) and raised in a feedlot condition for 112 days, with measurements to assess growth and slaughter, visual and carcass and meat traits. Data were submitted to variance and multivariate analyses. Nelore and Curraleiro Pé-Duro had similar Gluteus medius depths. Pantaneiro and Curraleiro Pé-Duro were superior for leg compactness index (P < 0.05) and had higher eye muscle area than Nelore (P < 0.05). Although there was no difference in daily weight gain and slaughter weight between breeds, Curraleiro Pé-Duro had a lower initial weight (264.80 kg) when compared to Nelore (346.80 kg; P < 0.05). Nelore and Curraleiro Pé-Duro deposited more fat than Pantaneiro (P < 0.05), while Curraleiro Pé-Duro and Pantaneiro had more muscle than Nelore (P < 0.05), which also had more bone and a higher percentage of second-quality cuts (P < 0.05). Meat from Nelore also showed lower succulence than Pantaneiro (P < 0.05) and higher shear force than the other breeds (P < 0.05). Pantaneiro's meat had the most capacity to retain water (P < 0.05), lower shear force (P < 0.05), and was more succulent (P < 0.05) when compared to the other breeds. Multivariate analysis showed that Pantaneiro, Curraleiro Pé-Duro, and Nelore breeds can be considered distinct in growth, carcass, and meat traits, with the local breeds showing superior meat traits. The local breeds Curraleiro Pé-Duro and Pantaneiro presented characteristics similar or better to those of the Nelore, proving to be animals with great productive potential and generate high meat quality under feedlot conditions.


Assuntos
Carne , Aumento de Peso , Bovinos/genética , Animais , Brasil , Fenótipo , Músculo Esquelético , Composição Corporal
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