Bacteria from the skin of amphibians promote growth of Arabidopsis thaliana and Solanum lycopersicum by modifying hormone-related transcriptome response.

Plants and microorganisms establish beneficial associations that can improve their development and growth. Recently, it has been demonstrated that bacteria isolated from the skin of amphibians can contribute to plant growth and defense. However, the molecular mechanisms involved in the beneficial effect for the host are still unclear. In this work, we explored whether bacteria isolated from three tropical frogs species can contribute to plant growth. After a wide screening, we identified three bacterial strains with high biostimulant potential, capable of modifying the root structure of Arabidopsis thaliana plants. In addition, applying individual bacterial cultures to Solanum lycopersicum plants induced an increase in their growth. To understand the effect that these microorganisms have over the host plant, we analysed the transcriptomic profile of A. thaliana during the interaction with the C32I bacterium, demonstrating that the presence of the bacteria elicits a transcriptional response associated to plant hormone biosynthesis. Our results show that amphibian skin bacteria can function as biostimulants to improve agricultural crops growth and development by modifying the plant transcriptomic responses.

Amphibian skin bacteria display antifungal activity and induce plant defense mechanisms against Botrytis cinerea.

Botrytis cinerea is the causal agent of gray mold, which affects a wide variety of plant species. Chemical agents have been used to prevent the disease caused by this pathogenic fungus. However, their toxicity and reduced efficacy have encouraged the development of new biological control alternatives. Recent studies have shown that bacteria isolated from amphibian skin display antifungal activity against plant pathogens. However, the mechanisms by which these bacteria act to reduce the effects of B. cinerea are still unclear. From a diverse collection of amphibian skin bacteria, three proved effective in inhibiting the development of B. cinerea under in vitro conditions. Additionally, the individual application of each bacterium on the model plant Arabidopsis thaliana, Solanum lycopersicum and post-harvest blueberries significantly reduced the disease caused by B. cinerea. To understand the effect of bacteria on the host plant, we analyzed the transcriptomic profile of A. thaliana in the presence of the bacterium C32I and the fungus B. cinerea, revealing transcriptional regulation of defense-related hormonal pathways. Our study shows that bacteria from the amphibian skin can counteract the activity of B. cinerea by regulating the plant transcriptional responses.

Transpiration Dynamics of Esparto Grass (Macrochloa tenacissima (L.) Kunth) in a Semi-Arid Mediterranean Climate: Unraveling the Impacts of Pine Competition.

Macrochloa tenacissima (M. tenacissima), or esparto, is a perennial tussock grass that coexists with Pinus halepensis (P. halepensis) in semi-arid Mediterranean woodlands. This research was carried out to explore diurnal transpiration at leaf level in esparto grass under different levels of pine-esparto competition and in contrasting environmental soil water conditions. The measurement period spanned from the summer of 2020 to the spring of 2021. The relationship between transpiration and competition was conducted in open and closed P. halepensis stands, and the type of leaf (green, senescent) and the maturity of the esparto grass were taken into account. We observed a higher control of transpiration in green leaves, and the correlations between the transpiration and pine competition were noted exclusively in this type of leaf. Our results demonstrated a significant impact of pine competitors (closed stands) on the transpiration of esparto grass, particularly during seasons characterized by scenarios of high water demand: the summer drought period and the commencement of the growing and flowering period (spring). Furthermore, our findings revealed a greater response to transpiration in mature bushes compared to young ones under severe water stress, indicating a higher adaptation to drought by esparto as it ages. Although our results confirmed that PAR increased transpiration in all seasons and in both stands, which is attributable to the heliophilia of esparto grass, the site effects on transpiration could also be attributable to competition for water, especially during periods of drought. These results may have important implications for the dynamics and management of these semi-arid mixed woodlands, as well as the planning of reforestation programs aimed at restoring esparto grass formations.

Morpho-anatomy of in vitro germination and cryopreservation of the orchid Cattleya crispa (Orchidaceae Morfoanatomía de la germinación in vitro y criopreservación de la orquídea Cattleya crispa (Orchidaceae) / Morfoanatomía de la germinación in vitro y criopreservación de la orquídea Cattleya crispa (Orchidaceae)

Introduction: Cattleya crispa is an ornamental epiphytic orchid with geographic distribution restricted to the Brazilian Atlantic Forest. Due to predatory extractivism and human-induced habitat loss, this species appears on the Red List of Brazilian Flora. Objective: To characterize morpho-anatomical aspects regarding germination and post-seminal development from C. crispa seeds; as well as studying the effect of cryopreservation on these seeds. Methods: We used light microscopy and electron microscopy to describe the microstructure of a 100 ripe seeds. We evaluated seed viability, seed germination, survival rate and protocorm weight in cryopreserved and non-cryopreserved material, with four replicas per treatment using 20 mg of plant material. Results: The seeds are fusiform, whitish yellow with a length from 700 to 900 µm and a water content of 5 %. Germination began seven days after sowing, the formation of the globular protocorm at 30 days and the formation of the seedling occurred 150 days. The persistent seed coat can compress the protocorm and cause it to collapse. The cryopreserved seeds presented 87.15 % viability, 78.32 % germination, 8.48 % survival and protocorms with 104.27 mg five months after sowing. Data wasn't different to non-cryopreserved seeds. Conclusions: The cryocapability of the seeds shows that cryopreservation can be used for long-term conservation. The results of this work contribute to the overall biology of C. crispa and to the propagation and storage of genetic material for conservation purposes.

Introducción: Cattleya crispa es una orquídea epífita ornamental con distribución geográfica restringida a la Mata Atlántica brasileña. Debido al extractivismo depredador y a la pérdida de hábitat inducida por el hombre, esta especie aparece en la Lista Roja de la Flora Brasileña. Objetivo: Caracterizar aspectos morfoanatómicos de la germinación y desarrollo inicial de semillas de C. crispa; así como estudiar el efecto de la criopreservación de estas semillas. Métodos: Utilizamos microscopía óptica, microscopía electrónica de barrido y microscopía electrónica de transmisión para describir la microestructura en 100 semillas maduras. Evaluamos la viabilidad de la semilla, la germinación de la semilla, la tasa de supervivencia y el peso de los protocormos en el material criopreservado y no criopreservado, con cuatro réplicas por tratamiento de 20 mg de material vegetal. Resultados: Las semillas son fusiformes, amarillo blanquecinas, con una longitud de 700 a 900 µm y un contenido de agua del 5 %. La germinación comenzó siete días después de la siembra, la formación del protocormo globular a los 30 días y la formación de la plántula a los 150 días. La cubierta de semilla persistente puede comprimir el protocormo y provocar su colapso. Las semillas criopreservadas presentaron 87.15 % de viabilidad, 78.32 % de germinación, 8.48 % de supervivencia y protocormos con 104.27 mg a los cinco meses de la siembra. Los datos no fueron diferentes a las semillas no criopreservadas. Conclusiones: La capacidad criogénica de las semillas muestra que la crioconservación puede utilizarse para la conservación a largo plazo. Los resultados de este trabajo contribuyen a la biología general de C. crispa y a la propagación y almacenamiento de material genético con fines de conservación.

Depth of Invasion: Influence of the Latest TNM Classification on the Prognosis of Clinical Early Stages of Oral Tongue Squamous Cell Carcinoma and Its Association with Other Histological Risk Factors.

BACKGROUND: The American Joint Committee on Cancer (AJCC), in its 8th edition, introduces modifications to the previous TNM classification, incorporating tumour depth of invasion (DOI). The aim of this research is to analyse the prognosis (in terms of disease-free survival and overall survival) of clinical early stage (I and II) squamous cell carcinomas of the oral tongue according to the DOI levels established by the AJCC in its latest TNM classification to assess changes to the T category and global staging system and to evaluate the association between DOI and other histological risk factors. METHODS: A retrospective longitudinal observational study of a series of cases was designed. All patients were treated with upfront surgery at our institution between 2010 and 2019. The variables of interest were defined and classified into four groups: demographic, clinical, histological and evolutive control. Univariate and multivariate analyses were carried out and survival functions were calculated using the Kaplan-Meier method. Statistical significance was established for p values below 0.05. RESULTS: Sixty-one patients were included. The average follow-up time was 47.42 months. Fifteen patients presented a loco-regional relapse (24.59%) and five developed distant disease (8.19%). Twelve patients died (19.67%). Statistically significant differences were observed, with respect to disease-free survival (p = 0.043), but not with respect to overall survival (p = 0.139). A total of 49.1% of the sample upstaged their T category and 29.5% underwent modifications of their global stage. The analysis of the relationship between DOI with other histological variables showed a significant association with the presence of pathological cervical nodes (p = 0.012), perineural invasion (p = 0.004) and tumour differentiation grade (p = 0.034). Multivariate analysis showed association between depth of invasion and perineural invasion. CONCLUSIONS: Depth of invasion is a histological risk factor in early clinical stages of oral tongue squamous cell carcinoma. Depth of invasion impacts negatively on patient prognosis, is capable per se of modifying the T category and the global tumour staging, and is associated with the presence of cervical metastatic disease, perineural invasion and tumoural differentiation grade.

Assessment of soil respiration process in a mangrove swamp of Panama's Bay.

Studies reveal that mangroves have the ability to store underground carbon more than a tropical forest, and this function is classified as the second most important to mitigate the effects of climate change. However, part of the carbon fixed returns to the atmosphere, and this is done through soil respiration. The present study seeks to quantify the total soil efflux (a subrogate of total soil respiration) that includes both autotrophic and heterotrophic soil efflux, emitted by a Panama's mangrove swamp, as well as to investigate what drivers are important. Firstly, 3 plots were established with predominant mangroves species, such as salty mangrove tree (Avicennia bicolor Standl.) and black mangrove tree (Avicennia germinans L.). Secondly, a forest inventory was carried out in one ha, resulting in 371 trees ha-1, where the salty mangrove tree prevailed with 219 individuals in front of the black mangrove tree, with 152 trees. In addition, tree level measurements were performed such as diameter at breast height (DBH), crown diameter and distance between trees. Third, using a Licor 6400XT infrared gas analyzer system and a meteorological tower, soil CO2 fluxes and air and soil temperature were measured respectively. Results showed a total of 33.61 t of CO2 ha-1 emitted by the soil of the mangrove in 3.5 months.

Embryonal Rhabdomyosarcoma of the Tongue in Adults.

(1) Background: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the first two decades of life. One third of cases appear in the head and neck, with 60% of these being embryonal type. RMS is extremely rare in adults, comprising only 1% of adult malignancies, and of those, only 3.3% are rhabdomyosarcomas. (2) Case report: A 46 y.o. male presented with a 1 cm exophytic pediculated painless lesion on the dorsum of his tongue, with progressive growth for 3 months. An excisional biopsy revealed an "embryonal rhabdomyosarcoma with fusocellular areas, with negative rearrangement for gen FOXO1A, negative MDM2 (only focal positivity), and positive INI-1". Subsequent contrast-enhanced MRI concluded the presence of a lesion with imprecise margins in the right half-tongue, 15 × 8 × 7 mm (longitudinal × transverse × craniocaudal), compatible with a sarcoma. The patient underwent a partial centrolingual glossectomy followed by reconstruction with a buccinator muscle local flap. After surgery, he received chemotherapy with eight cycles of VAC (vincristine, actinomycin, and cyclophosphamide) protocol. The patient is now disease free after 42 months, with good tongue function. (3) Discussion and conclusions: Embryonal RMS is an extremely rare sarcoma in adults, and the location in the tongue is even more exceptional (only two more similar cases are reported in the literature). The prognosis in adults is significantly poorer than in children. A complete margin-free resection with an adequate chemotherapy protocol is the treatment of choice in cases such as these.

Gobernar la sexualidad: análisis de la discusión de un proyecto de ley en chile / Governing sexuality: analysis of the discussion of a bill in chile / Governar a sexualidade: análise da discussão de um projeto de lei no chile

Resumen El artículo analiza los distintos posicionamientos y versiones sobre la sexualidad de de niños, niñas y jóvenes en la discusión en torno al del Proyecto de Ley que Establece Normas Generales en Materia de Educación sobre Afectividad, Sexualidad y Género para los Establecimientos Educacionales Reconocidos por el Estado entre marzo del 2019 y octubre del 2020 en Chile. Se realizó un estudio cualitativo con un corpus textual conformado por las transcripciones literales de las siete sesiones de audiencia en donde debatió el proyecto. Los resultados dan cuenta de cinco categorías: Liberalismo y desregulación, Desarrollo del ciclo vital, Disputa culturalista, Defensa de la familia, y Participación como acción. Se discute cómo los distintos posicionamientos se articulan desde la configuración de un modo de gobierno de las poblaciones por medio de la focalización estratégica en edades tempranas como mecanismo de preparación hacia la vida adulta.

Resumo O artigo analisa os diferentes posicionamentos e versões sobre a sexualidade de crianças e jovens na discussão em torno do Projeto de Lei que estabelece Normas Gerais para a Educação sobre Afetividade, Sexualidade e Gênero para Estabelecimentos de Ensino Reconhecidos pelo Estado entre março de 2019 e outubro de 2020 no Chile. Foi realizado um estudo qualitativo com um corpus textual composto pelas transcrições literais das sete sessões de audiência em que o projeto foi debatido. Os resultados revelam cinco categorias: Liberalismo e desregulamentação, Desenvolvimento do ciclo de vida, Disputas culturais, Defesa da família, e Participação como ação. Discute-se como os diferentes posicionamentos se articulam a partir da configuração de uma forma de governar as populações através de um direcionamento estratégico em idades iniciais como um mecanismo de preparação para a idade adulta.

Abstract The article analyzes the different positions and versions on the sexuality of boys, girls, and young people in the discussion around the Bill that establishes General Standards on Education on Affectivity, Sexuality and Gender for Educational Establishments Recognized by the State between March 2019 and October 2020 in Chile. A qualitative study was conducted with a textual corpus made up of the verbatim transcripts of the seven hearing sessions where the project was debated. The results show five categories: Liberalism and deregulation, Life cycle development, Culturalist dispute, Defense of the family, and Participation as action. It is discussed how the different positions are articulated from the configuration of a way of governing populations through the strategic focus on early ages as a mechanism of preparation for adult life.

Translation Comes First: Ancient and Convergent Selection of Codon Usage Bias Across Prokaryotic Genomes.

Codon usage is the outcome of different evolutionary processes and can inform us about the conditions in which organisms live and evolve. Here, we present R_ENC', which is an improvement to the original S index developed by dos Reis et al. (2004). Our index is less sensitive to G+C content, which greatly affects synonymous codon usage in prokaryotes, making it better suited to detect selection acting on codon usage. We used R_ENC' to estimate the extent of selected codon usage bias in 1800 genomes representing 26 prokaryotic phyla. We found that Gammaproteobacteria, Betaproteobacteria, Actinobacteria, and Firmicutes are the phyla/subphyla showing more genomes with selected codon usage bias. In particular, we found that several lineages within Gammaproteobacteria and Firmicutes show a similar set of functional terms enriched in genes under selected codon usage bias, indicating convergent evolution. We also show that selected codon usage bias tends to evolve in genes coding for the translation machinery before other functional GO terms. Finally, we discuss the possibility to use R_ENC' to predict whether lineages evolved in copiotrophic or oligotrophic environments.

Body-axis organization in tetrapods: a model-system to disentangle the developmental origins of convergent evolution in deep time.

Convergent evolution is a central concept in evolutionary theory but the underlying mechanism has been largely debated since On the Origin of Species. Previous hypotheses predict that developmental constraints make some morphologies more likely to arise than others and natural selection discards those of the lowest fitness. However, the quantification of the role and strength of natural selection and developmental constraint in shaping convergent phenotypes on macroevolutionary timescales is challenging because the information regarding performance and development is not directly available. Accordingly, current knowledge of how embryonic development and natural selection drive phenotypic evolution in vertebrates has been extended from studies performed at short temporal scales. We propose here the organization of the tetrapod body-axis as a model system to investigate the developmental origins of convergent evolution over hundreds of millions of years. The quantification of the primary developmental mechanisms driving body-axis organization (i.e. somitogenesis, homeotic effects and differential growth) can be inferred from vertebral counts, and recent techniques of three-dimensional computational biomechanics have the necessary potential to reveal organismal performance even in fossil forms. The combination of both approaches offers a novel and robust methodological framework to test competing hypotheses on the functional and developmental drivers of phenotypic evolution and evolutionary convergence.

Seeds cryopreservation of Vriesea reitzii Leme & A.F. Costa endemic bromeliad from Atlantic Rainforest / Criopreservação de sementes de Vriesea reitzii Leme & A.F. Costa bromélia endêmica da Mata Atlântica

Vriesea reitzii is an endemic bromeliad from the Atlantic Rainforest. The objective of this research was to evaluate the cryopreservation using the method of direct immersion of its seeds, collected from capsules at 120, 135, and 150 days after anthesis (DAA). The water content was determined before cryopreservation, while the germination percentage, germination speed index (GSI), and total soluble carbohydrates were quantified after cryopreservation. The highest percentage of moisture (17.6%) was observed in 120 DAA, while the highest percentage of germination (89.6%) and GSI (17.0) were observed in 150 DAA. Optical and transmission electron microscopy analyses were performed, and no cell damage or changes at the morpho-histological and ultrastructural levels were observed after the cryopreservation process. From these results, V. reitzii seeds can be classified as orthodox seeds and the cryopreservation (+LN) is an efficient tool for an ex situ conservation of this species.

Vriesea reitzii é uma bromélia endêmica da Mata Atlântica. O objetivo deste trabalho foi avaliar a criopreservação de sementes utilizando o método de imersão direta, coletadas de cápsulas aos 120, 135 e 150 dias após a antese (DAA). O teor de água foi determinado antes da criopreservação. A porcentagem de germinação, o índice de velocidade de germinação (GSI) e os carboidratos solúveis totais foram quantificados após a criopreservação. A maior porcentagem de umidade (17,6%) foi observada aos 120 DAA, enquanto a maior porcentagem de germinação (89,6%) e GSI (17,0) foram observadas aos 150 DAA. Em análises de microscopia ótica e eletrônica de transmissão não foram observados danos celulares ou alterações a nível morfohistológico e ultraestrutural após o processo de criopreservação. A partir desses resultados, as sementes de V. reitzii podem ser classificadas como ortodoxas e a criopreservação (+LN) é uma ferramenta eficiente para a conservação ex situ desta espécie.

Access to Contraceptive Services in Puerto Rico: An Analysis of Policy and Practice Change Strategies, 2015-2018.

CONTEXT: During the 2016-2017 Zika virus outbreak in Puerto Rico, preventing unintended pregnancy was a primary strategy to reduce Zika-related adverse birth outcomes. The Zika Contraception Access Network (Z-CAN) was a short-term emergency response intervention that used contraception to prevent unintended pregnancy among women who chose to delay or avoid pregnancy. OBJECTIVE: This analysis reports on the identified policy and practice change strategies to increase access to or provision of contraceptive services in Puerto Rico between 2015 and 2018. METHODS: A policy review was conducted to document federal- and territorial-level programs with contraceptive coverage and payment policies in Puerto Rico and to identify policy and practice change. Semistructured interviews with key stakeholders in Puerto Rico were also conducted to understand perceptions of policy and practice change efforts following the Zika virus outbreak, including emergency response, local, and policy efforts to improve contraception access in Puerto Rico. RESULTS: Publicly available information on federal and territorial programs with policies that facilitate access, delivery, and utilization of contraceptive coverage and family planning services in Puerto Rico to support contraceptive access was documented; however, interview results indicated that the implementation of the policies was often limited by barriers and that policy and practice changes as the result of the Zika virus outbreak were short-term. CONCLUSION: Consideration of long-term policy and practice changes related to contraceptive access is warranted. Similar analyses can be used to identify policies, practices, and perceptions in other settings in which the goal is to increase access to contraception or reduce unintended pregnancy.

Acute Aortic Syndrome Revisited: JACC State-of-the-Art Review.

The purpose of this paper is to describe all available evidence on the distinctive features of a group of 4 life-threatening acute aortic pathologies gathered under the name of acute aortic syndrome (AAS). The epidemiology, diagnostic strategy, and management of these patients has been updated. The authors propose a new and simple diagnostic algorithm to support clinical decision making in cases of suspected AAS, thereby minimizing diagnostic delays, misdiagnoses, and unnecessary advanced imaging. AAS-related entities are reviewed, and a guideline to avoid imaging misinterpretation is provided. Centralization of patients with AAS in high-volume centers with high-volume surgeons is key to improving clinical outcomes. Thus, the role of multidisciplinary teams, an "aorta code" (streamlined emergent care pathway), and aortic centers in the management of these patients is boosted. A tailored patient treatment approach for each of these acute aortic entities is needed, and as such has been summarized. Finally, a set of prevention measures against AAS is discussed.

Independent origins of powered flight in paravian dinosaurs?

Feathered dinosaurs discovered during the last decades have illuminated the transition from land to air in these animals, underscoring a significant degree of experimentation in wing-assisted locomotion around the origin of birds. Such evolutionary experimentation led to lineages achieving either wing-assisted running, four-winged gliding, or membrane-winged gliding. Birds are widely accepted as the only dinosaur lineage that achieved powered flight, a key innovation for their evolutionary success. However, in a recent paper in Current Biology, Pei and colleagues1 disputed this view. They concluded that three other lineages of paravian dinosaurs (those more closely related to birds than to oviraptorosaurs) - Unenlagiinae, Microraptorinae and Anchiornithinae - could have evolved powered flight independently. While we praise the detailed phylogenetic framework of Pei and colleagues1 and welcome a new attempt to understand the onset of flight in dinosaurs, we here expose a set of arguments that significantly weaken their evidence supporting a multiple origin of powered flight. Specifically, we maintain that the two proxies used by Pei and colleagues1 to assess powered flight potential in non-avian paravians - wing loading and specific lift - fail to discriminate between powered flight (thrust generated by flapping) and passive flight (gliding).

Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery.

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA-BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV-VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.

N-Acetylaspartyl-Glutamate Metabolism in the Cingulated Cortices as a Biomarker of the Etiology in ASD: A 1H-MRS Model.

As brain functional resonance magnetic studies show an aberrant trajectory of neurodevelopment, it is reasonable to predict that the degree of neurochemical abnormalities indexed by magnetic resonance spectroscopy (1H-MRS) might also change according to the developmental stages and brain regions in autism spectrum disorders (ASDs). Since specific N-Acetyl-aspartate (NAA) changes in children's metabolism have been found in the anterior cingulate cortex (ACC) but not in the posterior cingulate cortex (PCC), we analyzed whether the metabolites of ASD youths change between the cingulate cortices using 1H-MRS. l-glutamate (Glu) and l-Acetyl-aspartate (NAA) are products from the N-Acetyl-aspartyl-glutamate (NAAG) metabolism in a reaction that requires the participation of neurons, oligodendrocytes, and astrocytes. This altered tri-cellular metabolism has been described in several neurological diseases, but not in ASD. Compared to the typical development (TD) group, the ASD group had an abnormal pattern of metabolites in the ACC, with a significant increase of glutamate (12.10 ± 3.92 mM; p = 0.02); additionally, N-Acetyl-aspartyl-glutamate significantly decreased (0.41 ± 0.27 mM; p = 0.02) within ASD metabolism abnormalities in the ACC, which may allow the development of new therapeutic possibilities.

DEVELOPMENT AND VALIDATION OF A NEW LAPAROSCOPIC ENDOTRAINER FOR NEONATAL SURGERY AND REDUCED SPACES.

BACKGROUND: Pediatric laparoscopy box with sliding tray. Pediatric procedures have the difficulty of being performed in reduced spaces. Training in reduced spaces has proven to be different in complexity compared to adult laparoscopic endotrainers. AIM: To develop and validate a new neonatal/reduced-space endotrainer. METHODS: The simulator was tested and assessed by users with different skill levels and experience in laparoscopic pediatric surgery through an 8-item questionnaire. Construct validity was determined by evaluating the performance of each subject on nine exercises. RESULTS: A 10.5 x 10 x 18 cm acrylic simulator was created, with an internal working surface of 9 x 9 cm. An HD camera was incorporated, with a 0-180° range of movement. All exercises of a Basic Laparoscopic Training Program were adapted on a scale of 1:0.5 to fit in. From 49 participants, 42 (85.71%) answered the survey; 80.5% considered that the simulator reproduces similar conditions to procedures performed in children under one year of age; 61.1% thought that the simulator represents a difficulty identical to procedures performed in newborns; 73.7% considered that the neonatal simulator is more complicated than the adult simulator. Experts showed significantly better performance in all proposed exercises. CONCLUSION: The simulator has a high-quality image and design that allows training with basic tasks. The endotrainer permitted to discriminate between these different skill levels and was well evaluated by users with diverse surgical experience.