Tube Development Research Articles

Precision of morphogen gradients in neural tube development

Morphogen gradients encode positional information during development. How high patterning precision is achieved despite natural variation in both the morphogen gradients and in the readout process, is still largely elusive. Here, we show that the positional error of gradients in the mouse neural tube has previously been overestimated, and that the reported accuracy of the central progenitor domain boundaries in the mouse neural tube can be achieved with a single gradient, rather than requiring the simultaneous readout of opposing gradients. Consistently and independently, numerical simulations based on measured molecular noise levels likewise result in lower gradient variabilities than reported. Finally, we show that the patterning mechanism yields progenitor cell numbers with even greater precision than boundary positions, as gradient amplitude changes do not affect interior progenitor domain sizes. We conclude that single gradients can yield the observed developmental precision, which provides prospects for tissue engineering.

Microstructural development and mechanical properties of drop tube atomized Al-2.85 wt% Fe

• Fe solubility in α-Al increases with increasing cooling rate. • Micro-hardness increases with increasing cooling rate. • Al 13 Fe 4 forms at growth velocities in excess of 20 mm s −1 • α-Al was undercooled by 189 K Al-2.85 wt% Fe alloy has been subjected to non-equilibrium container-less solidification using a 6.5 m drop tube. Spherical samples were collected and sieved into 7 sizes fractions ranging from 850 μm to 53 μm, with the estimated cooling rates being 150 to 11000 K s -1 respectively. XRD analysis was employed on all droplet size fractions for identification and evolution of the phases, showing that Al, Al 6 Fe and Al 13 Fe 4 were formed for all sizes while Al 5 Fe 2 was observed only in droplets ≤ 150 μm in diameter. Microstructural evaluation was conducted by using SEM and optical microscopy, showing that droplet larger than 300 µm in diameter exhibited distinct morphologies; microcellular, dendritic α-Al with inter-dendritic Al 13 Fe 4 eutectic and an Al-Al 6 Fe eutectic region. With increasing cooling rate, the Al-Al 6 Fe region disappears. EDX analysis reveals that increasing the cooling rate increased the dissolved Fe content in α-Al from 0.37 wt% Fe to 1.105 wt% Fe, and correspondingly the eutectic fraction decreased from 49.7 vol.% to 26.7 vol.%. Measurement of the lamellar spacing allowed the eutectic growth velocity and interfacial undercooling to be calculated, wherein the Al-rich boundary of the eutectic coupled zone could be reconstructed. This shows a coupled zone skewed significantly towards the intermetallic side of the eutectic. In order to understand the effect of non-equilibrium the solidification on the mechanical properties micro hardness of the droplets was measured. The micro-hardness has risen from 55.3 HV 0.01 to 66.5 HV 0.01 for ≥ 850 μ m and ≤ 75 μ m droplets, respectively.

Development of Thermoplastic Composite Tube from HDPE/Barley Straw Fibers Using Extrusion Method

This paper was devoted to the technological process of manufacturing a biocomposites tube made of low-density polyethylene and barley straw fibers. 50% of HDPE, 42% barley straw, 5% of shungite (mineral filler), 2% Maleid F (N, N-metaphenylenediamine) as coupling agent, and 1% Hexol CLA as lubricant were pre-mixed before compounding. The compounding of the raw materials was carried out on a co-rotating twin-screw extruder. The resulting granules were fed into the single screw extruder to obtain thermoplastic composite tubes. The temperature regime for the HDPE/barley straw composite processing was in the range of 145-160 °C and the screw rotation speed was 50 rpm. The tensile strength and modulus were found to be 27.7 MPa and 1687 MPa, respectively. The water absorption (24-h) and density of the specimens were 1.43% and 1.158 g/cm3, respectively. Based on the findings obtained from the present study, it can be said that the barley straw can be efficiently used in the production of tube formed HDPE composites.

The proteome reveals the involvement of serine/threonine kinase in the recognition of self- incompatibility in almond

The self-incompatibility recognition mechanism determines whether the gametophyte is successfully fertilized between pollen tube SCF (SKP1–CUL1–F-box-RBX1) protein and pistil S-RNase protein during fertilization is unclear. In this study, the pistils of two almond cultivars ‘Wanfeng’ and ‘Nonpareil’ were used as the experimental materials after self- and nonself/cross-pollination, and pistils from the stamen-removed flowers were used as controls. We used fluorescence microscopy to observe the development of pollen tubes after pollination and 4D-LFQ to detect the protein expression profiles of ‘Wanfeng’ and ‘Nonpareil’ pistils and in controls. The results showed that it took 24–36 h for the development of the pollen tube to 1/3 of the pistil, and a total of 7684 differentially accumulated proteins (DAPs) were identified in the pistil after pollinating for 36 h, of which 7022 were quantifiable. Bioinformatics analysis based on the function of DAPs, identified RNA polymerases (4 DAPs), autophagy (3 DAPs), oxidative phosphorylation (3 DAPs), and homologous recombination (2 DAPs) pathways associated with the self-incompatibility process. These results were confirmed by parallel reaction monitoring (PRM), protein interaction and bioinformatics analysis. Taken together, these results provide the involvement of serine/threonine kinase protein in the reaction of pollen tube recognition the nonself- and the self-S-RNase protein. SignificanceGametophytic self-incompatibility (GSI) is controlled by the highly polymorphic S locus or S haplotype, with two linked self-incompatibility genes, one encoding the S-RNase protein of the pistil S-determinant and the other encoding the F-box/SLF/SFB (S haplotype-specific F-box protein) protein of the pollen S-determinant. The recognition mechanism between pollen tube SCF protein and pistil S-RNase protein is divided into nonself- and self-recognition hypothesis mechanisms. At present, two hypothetical mechanisms cannot explain the recognition between pollen and pistil well, so the mechanism of gametophytic self-incompatibility recognition is still not fully revealed. In this experiment, we investigated the molecular mechanism of pollen-pistil recognition in self-incompatibility using self- and nonself-pollinated pistils of almond cultivars ‘Wanfeng’ and ‘Nonpareil’. Based on our results, we proposed a potential involvement of the MARK2 (serine/threonine kinase) protein in the reaction of pollen tube recognition of the nonself- and the self-S-RNase protein. It provides a new way to reveal how almond pollen tubes recognize the self and nonself S-RNase enzyme protein.

A semi in vivo pollination technique to assess the level of gametophytic self-incompatibility and pollen tube growth in pear (Pyrus communis L.).

We describe a semi in vivo pollination technique to determine the compatibility relation between different pear cultivars. This assay provides a valuable addition to existing tools in GSI research. The gametophytic self-incompatibility (GSI) system in Pyrus inhibits fertilization by pollen that shares one of the two S-alleles of the style. Depending on their S-locus genotype, two pear cultivars therefore either show a cross-compatible, semi-compatible or incompatible interaction. Because GSI greatly influences seed and fruit set, accurate knowledge of the compatibility type of a cultivar is key for both pear fruit production and breeding. Currently, compatibility relations between different pear cultivars are generally assessed via S-genotyping. However, this approach is restricted to the currently known S-alleles in pear, and does not provide functional assessment of the level of (self-)incompatibility. We here present an optimized semi in vivo pollination assay, that enables quantitative analysis of (self-)incompatibility in pear, and that can also serve useful for more fundamental studies on pollen tube development and pollen-style interactions. This assay involves in vitro incubation of cut pollinated styles followed by microscopic counting of emerging pollen tubes at a specific time interval. The validity and selectivity of this method to determine compatibility interactions in pear is demonstrated in the cultivars "Celina" and "Packham's Triumph." Overall, this technique constitutes a valuable tool for quantitatively determining in vivo pollen tube growth and (cross-)compatibility in pear.

Divergent variant patterns among 19 patients with Rubinstein-Taybi syndrome uncovered by comprehensive genetic analysis including whole genome sequencing.

Rubinstein-Taybi syndrome (RSTS) is characterized by dysmorphic facial features, broad thumbs, and intellectual disability. CREB-binding protein (CREBBP) or E1A-binding protein P300 (EP300) are causative genes. To elucidate the underlying genetic and genomic architecture related to the RSTS phenotype, we performed comprehensive genetic analysis targeting CREBBP and/or EP300 in 22 clinically diagnosed patients. During the 11-year study period, we used several analysis methods including high-resolution melting, array-based comparative genomic hybridization, panel-based exome sequencing, whole exome sequencing, and whole genome sequencing (WGS). We identified the causative variants in 19 patients (86.3%), but they were variable and complex, so we must combine multiple analysis methods. Notably, we found genetic alterations in the non-coding regions of two patients (10.5%, 2/19): scattered deletions including a partial 5'-untranslated region of CREBBP in one patient (all coding exons were intact), and a deep 229-bp intronic deletion in another patient, resulting in a splicing error. Furthermore, we identified rare clinical findings: two patients with an EP300 variant showed abnormal development of the neural tube, and one patient with a CREBBP variant had anorectal atresia with a cloaca. Our findings expand the allelic heterogeneity of RSTS, underscore the utility of comprehensive genetic analysis, and suggest that WGS may be a practical diagnostic strategy.

Transcriptome analysis of maize pollen grains under drought stress during flowering

Drought stress is detrimental to male reproduction in maize (Zea mays L.), largely through reducing the quantity and quality of pollen grains. However, transcriptional response of maize pollen grains to drought stress has not been well documented. We compared pollen gene expression for a maize hybrid (ZhongDan909) under well-watered and drought-stress conditions, based on RNA-Seq validated by quantitative real-time PCR analysis. Expression of 6424 genes and 1302 transcripts was altered in pollen grains of maize subjected to 7 days of drought during flowering. Gene Ontology annotations showed 308 differentially expressed genes, annotated and classified into 50 primary functional categories. Kyoto Encyclopedia of Genes and Genomes analyses revealed 44 differentially expressed genes in nine metabolic pathways. In relation to carbohydrate metabolism pathways, there was downregulation of a polygalacturonase gene, which could reduce cell wall lysis in early pollen germination, and an increase in callose synthase transcripts along with reduced cellulase transcripts. These altered gene expressions responsible for cell wall integrity may inhibit the initiation of pollen tube growth. The onset of tube growth could be further impeded by observed changes in gene expression that potentially influence hormone metabolism (including downregulation of AUXIN RESPONSE FACTOR 18 and EIN3-BINDING F-BOX), reduce mitochondrial function, and alter protein translation. Genes with potential roles in adaptation were also altered in their transcript levels. These included genes encoding the upregulated transcription factor ZmNF-YC2, and the downregulated ZmbHLH13, a negative regulator of jasmonic acid responses. The upregulated flavin enzyme gene DIHYDROLIPOYL DEHYDROGENASE 1, associated with increased levels of reactive oxygen species, is of interest in relating redox homeostasis to stress adaptation. Overall, the analyses identified a suite of genes involved in the development of pollen grains and tubes and responsive to drought stress. The findings enhance understanding of the gene networks underlying compromised pollen viability under drought stress.

Effects of Zinc Oxide Nanoparticles on Neural Tube Development in Early Chicken Embryos.

In recent years, Zinc oxide nanoparticles (ZnO-NPs) have been widely used as a mineral filter in cosmetics. Therefore, the possible exposure of pregnant women to ZnO-NPs is gradually increasing. Thus, we aimed to investigate the effect of ZnO-NPs on neural tube development in early chicken embryos. Fifty pathogen-free fertilized eggs were initially incubated for thirty hours. The eggs were divided into 5 groups. In the control group (C) the egg's apex was opened and closed without any administration. In the distilled water group (DW), 10 microliters of distilled water were injected into the sub-blastodermic area. ZnO-NP suspensions were prepared in distilled water and injected sub-blastodermically into the low, medium and high dose ZnO-NP groups (10 mg/kg, 30 mg/kg, and 50 mg/kg, respectively). Incubation was completed in 72 hours, and embryological and neural tube development was evaluated histologically with a light microscope. Embryos in all groups were evaluated according to the Hamburger-Hamilton (HH) staging. It was observed that the staging progressed by the developmental process between 68-72 hours, which is equivalent to the 19-20th stage of HH. Differentiated otic vesicle, optic cup, lens vesicle, pharynx, and Rathke\'s pouch were all observed in embryo sections. Both forebrain and hindbrain vesicles were easily distinguished in the sections by cranial flexion. Neural tube closure defect was not detected in any of the groups. In our observations, ZnO-NPs did not affect neural tube development at the applied dose ranges. We believe that additional studies with higher doses using a higher number of subjects will help clarify the conflicting data in the literature.

Development of an Outer Tube That Reduces Nasal Pain and Epistaxis during Transnasal Endoscopy.

Transnasal endoscopy has recently become common in Japan. Although transnasal endoscopy has many advantages, nasal pain and epistaxis are common complaints. To reduce nasal pain and epistaxis, we developed a new tube sheath system for transnasal endoscopy. This new tube sheath system (outer sheath and inner tube), called the Nasal Slider, is produced by TOP Corporation, Japan. A tube sheath longer than the nasal concha is inserted to reduce pain along the nasal turbinate. Because the sheath is left in place, tubes can be passed through the nose multiple times without causing additional pain. A total of 34 consecutive patients (mean age 68.1 years; 22 men and 12 females) who had undergone transnasal endoscopy in the past were selected for transnasal endoscopy with the Nasal Slider. After the transnasal endoscopy was completed, patients who gave consent for use of the Nasal Slider were interviewed by using 3 questionnaires on nasal discomfort, nasal pain, and epistaxis. Because the transnasal endoscope passes inside the sheath, epistaxis can be prevented. Thirty of 34 selected patients underwent transnasal endoscopy using the Nasal Slider. Twenty-seven and 28 patients reported feeling less nasal discomfort and pain, respectively, with the Nasal Slider than during examinations without the Nasal Slider. No epistaxis developed in any patient examined with the Nasal Slider. The Nasal Slider appears to reduce nasal pain and epistaxis during transnasal endoscopy and is currently used in many hospitals in Japan.

Transcriptional analysis of gasoline engine exhaust particulate matter 2.5-exposed human umbilical vein endothelial cells reveals the different gene expression patterns related to the cardiovascular diseases

Particulate matter (PM) causes several diseases, including cardiovascular diseases (CVDs). Previous studies compared the gene expression patterns in airway epithelial cells and keratinocytes exposed to PM. However, analysis of differentially expressed gene (DEGs) in endothelial cells exposed to PM2.5 (diameter less than 2.5 μm) from fossil fuel combustion has been limited. Here, we exposed human umbilical vein endothelial cells (HUVECs) to PM2.5 from combustion of gasoline, performed RNA-seq analysis, and identified DEGs. Exposure to the IC50 concentrations of gasoline engine exhaust PM2.5 (GPM) for 24 h yielded 1081 (up-regulation: 446, down-regulation: 635) DEGs. The most highly up-regulated gene is NGFR followed by ADM2 and NUPR1. The most highly down-regulated gene is TNFSF10 followed by GDF3 and EDN1. Gene Ontology enrichment analysis revealed that GPM regulated genes involved in cardiovascular system development, tube development and circulatory system development. Kyoto Encyclopedia of Genes and Genomes and Reactome pathway analyses showed that genes related to cytokine–cytokine receptor interactions and cytokine signaling in the immune system were significantly affected by GPM. We confirmed the RNA-seq data of some highly altered genes by qRT-PCR and showed the induction of NGFR, ADM2 and IL-11 at a protein level, indicating that the observed gene expression patterns were reliable. Given the adverse effects of PM2.5 on CVDs, our findings provide new insight into the importance of several DEGs and pathways in GPM-induced CVDs.

Mutations in a barley cytochrome P450 gene enhances pathogen induced programmed cell death and cutin layer instability.

Disease lesion mimic mutants (DLMMs) are characterized by the spontaneous development of necrotic spots with various phenotypes designated as necrotic (nec) mutants in barley. The nec mutants were traditionally considered to have aberrant regulation of programmed cell death (PCD) pathways, which have roles in plant immunity and development. Most barley nec3 mutants express cream to orange necrotic lesions contrasting them from typical spontaneous DLMMs that develop dark pigmented lesions indicative of serotonin/phenolics deposition. Barley nec3 mutants grown under sterile conditions did not exhibit necrotic phenotypes until inoculated with adapted pathogens, suggesting that they are not typical DLMMs. The F2 progeny of a cross between nec3-γ1 and variety Quest segregated as a single recessive susceptibility gene post-inoculation with Bipolaris sorokiniana, the causal agent of the disease spot blotch. Nec3 was genetically delimited to 0.14 cM representing 16.5 megabases of physical sequence containing 149 annotated high confidence genes. RNAseq and comparative analysis of the wild type and five independent nec3 mutants identified a single candidate cytochrome P450 gene (HORVU.MOREX.r2.6HG0460850) that was validated as nec3 by independent mutations that result in predicted nonfunctional proteins. Histology studies determined that nec3 mutants had an unstable cutin layer that disrupted normal Bipolaris sorokiniana germ tube development.

Ethionine-mediated reduction of S-adenosylmethionine is responsible for the neural tube defects in the developing mouse embryo-mediated m6A modification and is involved in neural tube defects via modulating Wnt/\u03b2-catenin signaling pathway

Neural tube defects (NTDs) remain one of the most life-threatening birth defects affecting infants. Most patients with NTDs eventually develop lifelong disability, which cause significant morbidity and mortality and seriously reduce the quality of life. Our previous study has found that ethionine inhibits cell viability by disrupting the balance between proliferation and apoptosis, and preventing neural stem cells from differentiating into neurons and astrocytes. However, how ethionine participates in the pathogenesis of neural tube development through N6-methyladenosine (m6A) modification remains unknown. This study aims to investigate METTL3- and ALKBH5-mediated m6A modification function and mechanism in NTDs. Herein, our results demonstrate that SAM play not only a compensatory role, it also leads to changes of m6A modification in neural tube development and regulation. Additionally, these data implicate that METTL3 is enriched in HT-22 cells, and METTL3 knockdown reduces cell proliferation and increases apoptosis through suppressing Wnt/β-catenin signaling pathway. Significantly, overexpression of ALKBH5 can only inhibit cell proliferation, but cannot promote cell apoptosis. This research reveals an important role of SAM in development of NTDs, providing a good theoretical basis for further research on NTDs. This finding represents a novel epigenetic mechanism underlying that the m6A modification has profound and lasting implications for neural tube development.

Loss-of-function alleles of ZmPLD3 cause haploid induction in maize

Doubled haploid technology has been widely applied to multiple plant species and is recognized as one of the most important technologies for improving crop breeding efficiency. Although mutations in MATRILINEAL/Zea mays PHOSPHOLIPASE A1/NOT LIKE DAD (MTL/ZmPLA1/NLD) and Zea mays DOMAIN OF UNKNOWN FUNCTION 679 MEMBRANE PROTEIN (ZmDMP) have been shown to generate haploids in maize, knowledge of the genetic basis of haploid induction (HI) remains incomplete. Therefore, cloning of new genes underlying HI is important for further elucidating its genetic architecture. Here, we found that loss-of-function mutations of Zea mays PHOSPHOLIPASE D3 (ZmPLD3), one of the members from the phospholipase D subfamily, could trigger maternal HI in maize. ZmPLD3 was identified through a reverse genetic strategy based on analysis of pollen-specifically expressed phospholipases, followed by validation through the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR–Cas9) system. Mutations of ZmPLD3 resulted in a haploid induction rate (HIR) similar to that of mtl/zmpla1/nld and showed synergistic effects rather than functional redundancy on tripling the HIR (from 1.19% to 4.13%) in the presence of mtl/zmpla1/nld. RNA-seq profiling of mature pollen indicated that a large number of pollen-specific differentially expressed genes were enriched in processes related to gametogenesis development, such as pollen tube development and cell communication, during the double-fertilization process. In addition, ZmPLD3 is highly conserved among cereals, highlighting the potential application of these in vivo haploid-inducer lines for other important crop plant species. Collectively, our discovery identifies a novel gene underlying in vivo maternal HI and provides possibility of breeding haploid inducers with further improved HIR.

Identification of breast cancer molecular targets interacting with molecules present in the fruits of Antidesma bunius: In silico network pharmacology - based analysis

The fruit of Antidesma bunius has both medicinal and edible properties. In previous studies, the fruit extract of A. bunius showed anti-proliferation activity on breast cancer cells, but its functional components and anti-tumor mechanism are still unclear. In this research, the main active components of A. bunius fruits (detected by UHPLC-MS/MS) and the corresponding targets were analyzed by network pharmacology method, and its interactions were verified by molecular docking to explore the possible tumor suppressor mechanisms. A total of 24 active chemical components were screened from fruits extract of A. bunius，and 44 targets genes were intersected with breast cancer, among them, AKT1, ESR1, EGFR, EP300, ERBB2 and AR were the top core targets．The GO enrichment of target genes mainly involved processes of cellular lipid metabolism, response to hormones, tube development, and KEGG pathway analysis centers in cancer pathways present in breast, pancreatic and non-small cell lung cancer．The flavonoids in the fruits of A. bunius showed strong binding to the core targets by molecular docking analysis. These results strongly suggest that the flavonoids in the fruit of A. bunius can inhibit proliferation of breast cancer through multiple targets, mainly by ERK and PI3K-AKT pathways.

Study on interfacial bond behavior of recycled aggregate concrete filled stainless steel tubes (RAC-FSST)

In this work, the interfacial bond performance of recycled aggregate concrete filled stainless steel tube (RAC-FSST) members was investigated through the repeated push-out tests. Three coarse recycled aggregate (CRA) replacements (0, 50% and 100%) and two cross-sectional dimensions were considered in the experimental program. The failure pattern, bond stress-slip response and strain development of stainless steel tube were obtained, and the bond mechanisms under different loading stages were analyzed. Test results showed that the ultimate bond stress increases with the increasing CRA content and decreasing cross-sectional dimensions. Compared with CFST members having carbon steel, RAC-FSST members present lower bond stress. The macro-interlocking effect is obvious in the later loading stage, resulting in a significant increase in the post-peak bond slip curves. Finally, the ultimate bond strength and idealized bond stress-slip models for the RAC-FSST members were suggested on the basis of the test results.

Unraveling the complex genetics of neural tube defects: From biological models to human genomics and back.

Neural tube defects (NTDs) are a classic example of preventable birth defects for which there is a proven-effective intervention, folic acid (FA); however, further methods of prevention remain unrealized. In the decades following implementation of FA nutritional fortification programs throughout at least 87 nations, it has become apparent that not all NTDs can be prevented by FA. In the United States, FA fortification only reduced NTD rates by 28-35% (Williams et al.,2015). As such, it is imperative that further work is performed to understand the risk factors associated with NTDs and their underlying mechanisms so that alternative prevention strategies can be developed. However, this is complicated by the sheer number of genes associated with neural tube development, the heterogeneity of observable phenotypes in human cases, the rareness of the disease, and the myriad of environmental factors associated with NTD risk. Given the complex genetic architecture underlying NTD pathology and the way in which that architecture interacts dynamically with environmental factors, further prevention initiatives will undoubtedly require precision medicine strategies that utilize the power of human genomics and modern tools for assessing genetic risk factors. Herein, we review recent advances in genomic strategies for discovering genetic variants associated with these defects, and new ways in which biological models, such as mice and cell culture-derived organoids, are leveraged to assess mechanistic functionality, the way these variants interact with other genetic or environmental factors, and their ultimate contribution to human NTD risk.

A New Design of Large-format Streak Tube with Single-lens Focusing System

Abstract Streak tubes with large-format and high spatial resolution are central to mm-spatial-resolved STIL detection system and hyperspectral resolved ICF experiment. In this paper, we established a large-format streak tube with a three-coaxial-cylindrical single-lens focusing system, a spherically curved photocathode and phosphor screen model in CST Particle Studio. The temporal and spatial resolution were calculated and mimicked based on the Monte-Carlo sampling method in static and dynamic mode. The simulated results show that the static spatial resolution reaches 50 lp/mm over the whole 50 mm effective photocathode length, and the physical temporal resolution is better than 45 ps. Furthermore, in dynamic working mode, the streak tube can achieve spatial resolution of 10 lp/mm and temporal resolution of 60 ps. The simulation results will be used to guide the design and production for large-format with high spatial resolution streak tube development.

Embryotoxicity of Yangambin Isolated from Ocotea duckei Vattimo-Gil in Gallus gallus domesticus Embryos

Pharmacognosy Research,2021,13,3,135-139.DOI:10.5530/pres.13.3.5Published:June 2021Type:Original ArticleAuthors:Thiago Felix da Silva, Maria Isabel de Assis Lima Castro, Marta Gerusa Soares de Lucena, Camilla Vila Nova Soares Silva, Laisla Rangel Peixoto, Eliane Alves Bandeira de Carvalho, Silvania Tavares Paz, Beathryz Lethycya Almeida Guimarães, José Maria Barbosa Filho, and Eliete Cavalcanti da Silva Author(s) affiliations:Thiago Felix da Silva1,*, Maria Isabel de Assis Lima Castro2, Marta Gerusa Soares de Lucena3, Camilla Vila Nova Soares Silva4, Laisla Rangel Peixoto5, Eliane Alves Bandeira de Carvalho6, Silvania Tavares Paz7, Beathryz Lethycya Almeida Guimarães3, José Maria Barbosa Filho8, Eliete Cavalcanti da Silva1 1Postgraduate Program in Morphotechnology - Federal University of Pernambuco, Recife, PE, BRAZIL. 2Master of Sciences; Postgraduate Program in Biological Sciences - Federal University of Pernambuco, Recife, PE, BRAZIL. 3Department of Histology and Embryology - Federal University of Pernambuco, Recife, PE, BRAZIL. 4Multiprofessional Residency Program in Health Surveillance - Recife Health Department, Recife, PE, BRAZIL. 5Master of Sciences; Institute of Drugs and Medicines Research - Federal University of Paraíba, João Pessoa, PB, BRAZIL. 6Master of Sciences; Postgraduate Program in Biological Sciences - Federal University of Pernambuco, Recife, PE, BRAZIL. 7Master of Sciences; Department of Pathology - Federal University of Pernambuco, Recife, PE, BRAZIL. 8Institute of Drugs and Medicines Research - Federal University of Paraíba, João Pessoa, PB, BRAZIL. Abstract:Introduction: Yangambin, a lignan predominant in the leaves of Ocotea duckei Vattimo-Gil, has several biological activities, such as anti-convulsant, analgesic, anti-inflammatory and leishmanicidal. Objectives: The aim of this study was to evaluate the embryotoxicity of yangambin on the neurodevelopment of Gallus gallus domesticus embryos. Materials and Methods: 120 fertilized eggs were divided in three groups: G1 (PBS with 0.1 % Tween 80), G2 (50 μg/ml yangambin) and G3 (65 μg/ml yangambin) and each egg was inoculated with 100 μL of the respective solutions. The fertilized eggs were incubated at a temperature of 37.5°C, with a relative humidity of 65% to 75%, for 48 hr and then their embryos were histologically processed. Results: In staging, carried out according to Hamburger and Hamilton (1951), variations of stages were identified. In all groups, the morphological analysis revealed the closure of the anterior neuropore and absence of malformations in the optic vesicles and in the secondary encephalic vesicles. In the caudal region, a standard development of the neural tube was observed, with well-segmented somites and regression of the primitive line. The cross sections showed that the internal structure of the somite’s, composed of dermatome, myotome and sclerotome, was preserved. The statistical analysis did not show significant differences between the groups regarding the morphometry of the cephalic and caudal regions of the neural tube. Conclusion: Yangambin did not show embryotoxic effects on the neurodevelopment of Gallus gallus domesticus embryos, under the tested conditions. Keywords:Chicken embryo, Lauraceae, Lignan, Neurodevelopment, Secondary metabolitesView:PDF (809.58 KB)

Effect of ondansetron application on neural tube development in 48-hour chick embryos

The study aims to show that ondansetron, which is used safely in pregnant women, can cause serious side effects. Neural tube defects are among the most common congenital malformations of the central nervous system. It is known that genetic predisposition, environmental factors, and some drugs play an important role in the development of neural tube defects. Ondansetron is a selective 5-hydroxytryptamine-3 receptor antagonist used in the treatment of cancer, nausea, and vomiting during pregnancy and after anesthesia. In the literature studies, it was not found that developmental anomalies were observed. Seventy-five free specific pathogen eggs were incubated for 32 hours and divided into five groups of 15 eggs each, including a control group. Ondansetron was administered to these five groups by sub-blastoderm route in 4 different doses with a Hamilton microinjector. At 48 hours of incubation, the embryos were dissected and examined morphologically and histopathologically. At the end of the study, a significant dose-dependent decrease was observed in crown-rump lengths, somite numbers, and mean the number of silver-dyed nucleolar regulatory regions (AgNOR) and total AgNOR / nuclear area ratios. Statistically significant differences were observed between the experimental groups in terms of neural tube closure (p <0.05). Ondansetron has been shown to affect neuronal development and vertebral growth in chicken embryos depending on increasing doses.

Development of a water-filled four-sensor impedance tube

Four-sensor impedance tubes are readily utilized for characterization of the acoustic properties of materials in a gaseous host medium, as described in the standard ASTM E2611-19. Similar acoustic characterization is desired for materials submersed in water. Previous studies have documented the challenges of performing measurements in water-filled impedance tubes due to interaction with the elastic tube wall and difficulty in obtaining a suitable end-termination condition. Building upon previous demonstration of a two-sensor water-filled impedance tube [J. Acoust. Soc. Am. 113, 3245 (2003)], this paper discusses the development and demonstration of a four-sensor water-filled impedance tube with an anechoic termination. The technique utilizes two sensors on each side of the test section to simultaneously characterize both the incident and transmitted standing wave field and extract the complex impedance and wavenumber from the test sample. Discussion will focus on the challenges of performing such measurements in a water-filled tube along with methods for overcoming these challenges. Validation measurements of homogeneous materials in the 1–10 kHz band will be presented to demonstrate that both the complex impedance and wavenumber of a material submersed in water can be extracted using this approach. [Work supported by ONR.]