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Purpose: In respiratory disorders such as thoracic insufficiency syndrome (TIS), the quantitative study of the regional motion of the left hemi-diaphragm (LHD) and right hemi-diaphragm (RHD) can give detailed insights into the distribution and severity of the abnormalities in individual patients. Dynamic magnetic resonance imaging (dMRI) is a preferred imaging modality for capturing dynamic images of respiration since dMRI does not involve ionizing radiation and can be obtained under free-breathing conditions. Using 4D images constructed from dMRI of sagittal locations, diaphragm segmentation is an evident step for the said quantitative analysis of LHD and RHD in these 4D images. Methods: In this paper, we segment the LHD and RHD in three steps: recognition of diaphragm, delineation of diaphragm, and separation of diaphragm along the mid-sagittal plane into LHD and RHD. The challenges involved in dMRI images are low resolution, motion blur, suboptimal contrast resolution, inconsistent meaning of gray-level intensities for the same object across multiple scans, and low signal-to-noise ratio. We have utilized deep learning (DL) concepts such as Path Aggregation Network and Dual Attention Network for the recognition step, Dense-Net and Residual-Net in an enhanced encoder-decoder architecture for the delineation step, and a combination of GoogleNet and Recurrent Neural Network for the identification of the mid-sagittal plane in the separation step. Due to the challenging images of TIS patients attributed to their highly distorted and variable anatomy of the thorax, in such images we localize the diaphragm using the auto-segmentations of the lungs and the thoraco-abdominal skin. Results: We achieved an average±SD mean-Hausdorff distance of â¼3±3 mm for the delineation step and a positional error of â¼3±3 mm in recognizing the mid-sagittal plane in 100 3D test images of TIS patients with a different set of â¼430 3D images of TIS patients utilized for building the models for delineation, and separation. We showed that auto-segmentations of the diaphragm are indistinguishable from segmentations by experts, in images of near-normal subjects. In addition, the algorithmic identification of the mid-sagittal plane is indistinguishable from its identification by experts in images of near-normal subjects. Conclusions: Motivated by applications in surgical planning for disorders such as TIS, we have shown an auto-segmentation set-up for the diaphragm in dMRI images of TIS pediatric subjects. The results are promising, showing that our system can handle the aforesaid challenges. We intend to use the auto-segmentations of the diaphragm to create the initial ground truth (GT) for newly acquired data and then refining them, to expedite the process of creating GT for diaphragm motion analysis, and to test the efficacy of our proposed method to optimize pre-treatment planning and post-operative assessment of patients with TIS and other disorders.
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Bisphenol A (BPA) is among the extensively researched environmental endocrine-disrupting chemicals (EDCs), and its utilization is restricted owing to the detrimental impacts it has on human health. Bisphenol AP (BPAP) is one of the alternatives to BPA, but the influence of BPAP on human health has not been elucidated. The objective of the current research was to determine the influence of BPAP exposure on the in vitro maturation of mouse oocytes and to explore its potential reproductive toxicity. BPAP exposure was found to inhibit polar body extrusion during mouse oocyte maturation, resulting in an arrest at the metaphase I stage of meiosis. Exposure to BPAP led to sustained activation of BubR1, preventing the degradation of both Securin and Cyclin B1. Mechanistically, BPAP exposure disrupts spindle assembly and chromosome alignment. Levels of acetylated α-tubulin were significantly elevated in BPAP-treated oocytes, reflecting decreased spindle stability. Exposure to BPAP also induced DNA damage and impaired DNA damage repair. In addition, BPAP exposure altered histone modification levels. In summary, this investigation suggests that exposure to BPAP can influence cytoskeletal assembly, interfere with cell cycle progression, induce DNA damage, alter histone modifications, and ultimately impede oocyte meiotic maturation. This investigation enhances understanding of the impact of bisphenol analogs on female gametes, underscoring that BPAP cannot be considered a reliable replacement for BPA.
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Antioxidant dipeptide Phe-Cys (FC) could dramatically improve yeast cells resistance to ethanol-oxidation cross-stress, but the regulatory mechanisms remain unclear. Therefore, transcriptomic and proteomic analyses were conducted to investigate the effects of FC treatment on yeast under ethanol-oxidation cross-stress. Following FC supplementation, 875 differential expressed genes (DEGs) and 1296 differential expressed proteins (DEPs) were identified. Integrated analysis revealed a substantial enrichment of DEGs and DEPs in the KEGG pathways of carbon metabolism, amino acid biosynthesis, cofactor biosynthesis, and glycolysis/gluconeogenesis. Furthermore, FC improved yeast cell membrane integrity by promoting fatty acids and steroids biosynthesis, and implemented a high-energy strategy by upregulating glycolysis and oxidative phosphorylation. Additionally, alterations in DEGs and DEPs levels associated with amino acids metabolism accelerated protein synthesis and enhanced cell viability. In conclusion, this study elucidated the response mechanisms of yeast to FC treatment under ethanol-oxidation cross-stress, providing a theoretical basis for the application of FC in high-gravity brewing.
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To investigate the protective effects of various wall materials on probiotics, two types of Lactiplantibacillus plantarum 90 (Lp90) microcapsules were prepared using sodium alginate and chitosan (Lp-AC), soy protein isolate (SPI) and reducing sugars conjugate (Lp -MRP) as wall materials, respectively. The physical properties, cell viability under different conditions and the application of the microcapsules were investigated. Results showed that the selected wall materials were safe to Lp90 and their simulated digestion products exhibited antioxidant activities and prebiotic properties. The encapsulation efficiencies of Lp-AC and Lp-MRP were above 80 %. Both microcapsules significantly enhanced cell survival rates under various conditions including low pH, bile salts, thermal processing, mechanical force, storage, and gastrointestinal digestion, with Lp-MRP demonstrating superior protective effects. When incorporated into milk and orange juice and stored at 4 °C for 28 d, the colony counts of beverages containing Lp90 microcapsules exceeded 6 Log CFU/mL, with minimal changes in total soluble solids. Lp-MRP exhibited higher cell viability and smaller viscosity changes at 25 °C for 28 d. Therefore, the single-layer encapsulation using SPI and reducing sugars conjugate showed promise over traditional chitosan-alginate double-layer encapsulation concerning probiotic protection, targeted delivery, and application.
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The antioxidant dipeptides (Ala-His, AH; Thr-Tyr, TY; and Phe-Cys, FC) significantly enhanced the lager yeast tolerance of ethanol stress. The enhancement mechanisms were further elucidated through physiological responses and metabolomics analysis. The results indicated that antioxidant dipeptides significantly increased the lager yeast biomass and budding rate. The primary mechanisms by which antioxidant dipeptides improved lager yeast tolerance involved decreasing intracellular reactive oxygen species (ROS) levels and increasing energy metabolism. Specifically, the addition of FC resulted in a 27.44% reduction in intracellular ROS content and a 26.14% increase in the ATP level compared to the control. Metabolomics analysis further explored the potential mechanisms underlying the protective effects of FC, identifying 63 upregulated and 103 downregulated metabolites. The analysis revealed that FC altered intracellular metabolites related to glutathione metabolism, purine metabolism, starch and sucrose metabolism, and ABC transporters, thereby enhancing yeast stress tolerance. The results suggest that FC is an effective enhancer for improving lager yeast tolerance to ethanol stress.
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Methylmercury chloride (MMC) is a persistent heavy metal contaminant that can bioaccumulate in humans via the food chain, exerting detrimental effects on health. Nevertheless, the specific influence of MMC on oocyte meiotic maturation has yet to be elucidated. This research demonstrated that MMC exposure during the in vitro cultivation of mouse oocytes did not influence germinal vesicle breakdown but markedly decreased oocyte maturation rates. Subsequent analysis indicated that MMC exposure resulted in aberrant spindle morphology and disorganized chromosome alignment, alongside continuous activation of the spindle assembly checkpoint (SAC). However, MMC exposure didn't alter the localization pattern of microtubule-organizing center-associated proteins. MMC exposure considerably diminished the acetylation level of α-tubulin, signifying reduced microtubule stability. Additionally, MMC exposure disrupted the dynamic alterations of F-actin. MMC exposure didn't affect mitochondrial localization, mitochondrial membrane potential, adenosine triphosphate content or the concentrations of reactive oxygen species. Nonetheless, MMC exposure triggered DNA damage and modified histone modification levels. Consequently, the defects in oocyte maturation induced by MMC exposure can be attributed to impaired cytoskeleton dynamics and DNA damage. This study offers the first comprehensive elucidation of the negative impacts of MMC on oocyte maturation, highlighting the potential reproductive health risks associated with MMC exposure.
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Currently, antibody drugs targeting programmed cell death ligand 1 (PD-L1) have achieved promising results in cancer treatment, while the development of small-molecule drugs lags behind. In this study, we designed and synthesized a series of PD-L1-degrading agents based on the PROTAC design principle, utilizing the PD-L1 inhibitor A56. Through systematic screening of ligands and linkers and investigating the structure-activity relationship of the degraders, we identified two highly active compounds, 9i and 9j. These compounds enhance levels of CD4+, CD8+, granzyme B, and perforin, demonstrating significant in vivo antitumor effects with a tumor growth inhibition (TGI) of up to 57.35 %. Both compounds facilitate the internalization of PD-L1 from the cell surface and promote its degradation through proteasomal and lysosomal pathways, while also maintaining inhibition of the PD-1/PD-L1 interaction. In summary, our findings provide a novel strategy and mechanism for developing biphenyl-based PROTAC antitumor drugs targeting and degrading PD-L1.
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Antineoplásicos , Antígeno B7-H1 , Proliferação de Células , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptor de Morte Celular Programada 1 , Humanos , Antígeno B7-H1/metabolismo , Antígeno B7-H1/antagonistas & inibidores , Relação Estrutura-Atividade , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Estrutura Molecular , Animais , Proliferação de Células/efeitos dos fármacos , Camundongos , Relação Dose-Resposta a Droga , Linhagem Celular Tumoral , Quimera de Direcionamento de ProteóliseRESUMO
Minimal hepatic encephalopathy (MHE) has a substantial impact on the clinical outcomes and quality of life (QOL) of patients with cirrhosis. However, timely diagnosis and intervention are challenging due to sophisticated diagnostic methods. In this study, 673 healthy controls and 905 patients with cirrhosis were screened, and 660 healthy controls and 757 patients with cirrhosis, divided into the test (292 patients) and validation (465 patients) cohort, were analyzed after screening. A diagnostic model of the Stroop test (Stroop-CN) was constructed by multivariate linear regression based on the results of healthy controls. The prevalence of MHE and the comparison results with psychometric hepatic encephalopathy score through the Stroop-CN model were stable in the test and validation cohorts. Moreover, the prevalence of MHE remained significantly higher in patients with worse disease conditions marked as high Child-Pugh grades and the Model for End-stage Liver Disease and Sodium (MELD-Na) scores in the test and validation cohort. The EuroQol 5-D questionnaire revealed that patients with MHE had a worse QOL than those without MHE both in the test and validation cohort. In conclusion, an easy and practical Stroop-CN model for MHE diagnosis based on the EncephalApp is established. It is found that a considerable number of Chinese patients with cirrhosis experience MHE, which significantly impacts their QOL.
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Organ segmentation is a fundamental requirement in medical image analysis. Many methods have been proposed over the past 6 decades for segmentation. A unique feature of medical images is the anatomical information hidden within the image itself. To bring natural intelligence (NI) in the form of anatomical information accumulated over centuries into deep learning (DL) AI methods effectively, we have recently introduced the idea of hybrid intelligence (HI) that combines NI and AI and a system based on HI to perform medical image segmentation. This HI system has shown remarkable robustness to image artifacts, pathology, deformations, etc. in segmenting organs in the Thorax body region in a multicenter clinical study. The HI system utilizes an anatomy modeling strategy to encode NI and to identify a rough container region in the shape of each object via a non-DL-based approach so that DL training and execution are applied only to the fuzzy container region. In this paper, we introduce several advances related to modeling of the NI component so that it becomes substantially more efficient computationally, and at the same time, is well integrated with the DL portion (AI component) of the system. We demonstrate a 9-40 fold computational improvement in the auto-segmentation task for radiation therapy (RT) planning via clinical studies obtained from 4 different RT centers, while retaining state-of-the-art accuracy of the previous system in segmenting 11 objects in the Thorax body region.
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Meaning in life, which has two possible sources: self-acceptance and social support, is essential to the mental health and development of college students. The current study aims to further clarify the symptom-level relations between meaning in life, self-acceptance, and social support, finding possible ways to improve meaning in the life of college students. Thousand three hundred and forty-eight Chinese college students completed the online questionnaire, including Self-acceptance Questionnaire, Social Support Rating Scale, and Meaning in Life Questionnaire and the data from 1,263 participants was used. Cross-sectional network analysis was used to examine the relation between self-acceptance and social support. We also explored the relation between dimensions of self-acceptance and social support and meaning in life using the flow network. The results show symptom "SlA" (self-acceptance) is the bridge symptom linking self-acceptance and social support. In the flow diagrams, "SlA" is directly and positively associated with the presence of meaning. Objective Support shares the strongest positive association with the search for meaning. The symptom "SIA" may be an important targeting symptom when trying to improve the meaning in life of college students. Additionally, social support is essential for college students to develop meaning in life.
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3-methyl-4-nitrophenol (PNMC), a degradation product of organophosphorus insecticides and a byproduct of fuel combustion, exerting endocrine-disrupting effects. However, its impact on the meiotic process of oocytes remains unclear. In the present study, we investigated the effects of PNMC on meiotic maturation of mouse oocytes in vitro and related mechanisms. Morphologically, PNMC-exposure affected germinal vesicle breakdown (GVBD) and polar body extrusion (PBE) in mouse oocytes. Proteomic analysis suggested that PNMC-exposure altered oocyte protein expression that are associated with cytoskeleton, mitochondrial function and oxidative stress. Further studies demonstrated that PNMC-exposure disrupted spindle assembly and chromosome alignment, caused sustained activation of spindle assembly checkpoint (SAC), and arrested meiosis in oocytes. Specifically, PNMC-exposure interfered with the function of microtubule organizing centers (MTOCs) by significantly reducing phosphorylated mitogen activated protein kinase (p-MAPK) expression and disrupting the localization of Pericentrin and p-Aurora A, leading to spindle assembly failure. Besides, PNMC-exposure also increased α-tubulin acetylation, decreased microtubule stability. Moreover, PNMC-exposure impaired mitochondrial function, evidenced by abnormal mitochondrial distribution, decreased mitochondrial membrane potential and ATP levels, release of Cytochrome C into the cytoplasm, and elevated ROS levels. As a result, exposure to PNMC caused DNA damage and early apoptosis in oocytes. Fortunately, melatonin was able to promote oocyte maturation by removing the excessive ROS and enhancing mitochondrial function. These results highlight the adverse effects of PNMC on meiotic maturation, and underscore the protective role of melatonin against PNMC-induced damage.
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Meiose , Melatonina , Mitocôndrias , Oócitos , Fuso Acromático , Animais , Oócitos/efeitos dos fármacos , Melatonina/farmacologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Feminino , Fuso Acromático/efeitos dos fármacos , Meiose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes , Inseticidas/toxicidadeRESUMO
A series of novel 2-arylmethoxy-4-(2-fluoromethyl-biphenyl-3-ylmethoxy) benzylamine derivatives was designed, synthesized, and evaluated for their antitumor effects as PD-1/PD-L1 inhibitors both in vitro and in vivo. Firstly, the ability of these compounds to block the PD-1/PD-L1 immune checkpoint was assessed using the homogeneous time-resolved fluorescence (HTRF) assay. Two of the compounds can strongly block the PD-1/PD-L1 interaction, with IC50 values of less than 10 nM, notably, compound HD10 exhibited significant clinical potential by inhibiting the PD-1/PD-L1 interaction with an IC50 value of 3.1 nM. Further microscale thermophoresis (MST) analysis demonstrated that HD10 had strong interaction with PD-L1 protein. Co-crystal structure (2.7 Å) analysis of HD10 in complex with the PD-L1 protein revealed a strong affinity between the compound and the target PD-L1 dimer. This provides a solid theoretical basis for further in vitro and in vivo studies. Next, a typical cell-based experiment demonstrated that HD10 could remarkably prevent the interaction of hPD-1 293 T cells from human recombinant PD-L1 protein, effectively restoring T cell function, and promoting IFN-γ secretion in a dose-dependent manner. Moreover, HD10 was effective in suppressing tumor growth (TGI = 57.31 %) in a PD-1/PD-L1 humanized mouse model without obvious toxicity. Flow cytometry, qPCR, and immunohistochemistry data suggested that HD10 inhibits tumor growth by activating the immune system in vivo. Based on these results, it seems likely that HD10 is a promising clinical candidate that should be further investigated.
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Antineoplásicos , Antígeno B7-H1 , Benzilaminas , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptor de Morte Celular Programada 1 , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/metabolismo , Animais , Camundongos , Relação Estrutura-Atividade , Benzilaminas/farmacologia , Benzilaminas/química , Benzilaminas/síntese química , Estrutura Molecular , Relação Dose-Resposta a Droga , Proliferação de Células/efeitos dos fármacos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/síntese química , Inibidores de Checkpoint Imunológico/química , Linhagem Celular Tumoral , Feminino , Modelos MolecularesRESUMO
Plant-derived extracellular vesicles (PLEVs), as a type of naturally occurring lipid bilayer membrane structure, represent an emerging delivery vehicle with immense potential due to their ability to encapsulate hydrophobic and hydrophilic compounds, shield them from external environmental stresses, control release, exhibit biocompatibility, and demonstrate biodegradability. This comprehensive review analyzes engineering preparation strategies for natural vesicles, focusing on PLEVs and their purification and surface engineering. Furthermore, it encompasses the latest advancements in utilizing PLEVs to transport active components, serving as a nanotherapeutic system. The prospects and potential development of PLEVs are also discussed. It is anticipated that this work will not only address existing knowledge gaps concerning PLEVs but also provide valuable guidance for researchers in the fields of food science and biomedical studies, stimulating novel breakthroughs in plant-based therapeutic options.
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Vesículas Extracelulares , Plantas , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/química , Plantas/química , Plantas/metabolismo , Humanos , AnimaisRESUMO
BACKGROUND: Previous studies have indicated a correlation between maternal imbalances in essential trace elements during pregnancy and the occurrence of spontaneous abortion (SA). Nonetheless, the impact of these elements from both partners and during the preconception period remains unexplored. OBJECTIVE: This study sought to evaluate the relationship between preconception essential trace elements and spontaneous abortion (SA) based on husband-wife dyads. METHODS: This study selected 390 couples with spontaneous abortion (SA) and 390 matched couples with live births from a preconception cohort of 33,687 couples. Urine samples collected prior to pregnancy were analyzed for ten essential trace elements (Se, Cr, Mo, Cu, Zn, Fe, Mn, V, Co, and Ni) using inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: Multivariate conditional logistic regression analysis identified that elevated concentrations of Zn (OR = 0.73) and Ni (OR = 0.69) in couples were associated with a reduced risk of SA, whereas elevated levels of Cr (OR = 1.30) and Mn (OR = 1.39) were linked to an increased risk. Restricted cubic spline models suggested a U-shaped association between couples' Cu and Co concentrations and SA. Bayesian Kernel Machine Regression further supported a U-shaped relationship between the mixture of ten elements and SA, showing significant protection at the 50th and 55th percentiles compared to the 10th percentile. Additionally, the effects of Cr, Zn, Mn, and Ni on SA varied when the concentrations of the other nine elements were held constant at their 25th, 50th, and 75th percentiles. Stratified analysis revealed that maternal Cu (OR = 0.43) and Fe (OR = 0.63) reduced the risk of SA when paternal Cu and Fe were in the lower quartile. Conversely, maternal Cu (OR = 2.03) and Fe (OR = 1.77) increased the risk of SA when paternal concentrations were in the higher quartile. Similar patterns were observed for Cr, Mn, Co, and Zn. CONCLUSION: Elevated urinary concentrations of Zn and Ni in couples were associated with a reduced risk of SA, while higher levels of Cr and Mn were linked to an increased risk. Cu, Co, and a mixture of ten essential trace elements exhibited a U-shaped relationship with SA. The impact of certain essential trace elements (Cu, Fe, Cr, Mn, Co, and Zn) on SA in one partner was influenced by their concentrations in the other partner.
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Aborto Espontâneo , Oligoelementos , Humanos , Feminino , Oligoelementos/urina , Oligoelementos/análise , Estudos de Casos e Controles , Aborto Espontâneo/epidemiologia , Aborto Espontâneo/urina , Adulto , Gravidez , Masculino , Zinco/urina , Adulto Jovem , Cobre/urina , Cônjuges/estatística & dados numéricos , Níquel/urina , Poluentes Ambientais/urinaRESUMO
Purpose To investigate free-breathing thoracic bright-blood four-dimensional (4D) dynamic MRI (dMRI) to characterize aeration of parenchymal lung tissue in healthy children and patients with thoracic insufficiency syndrome (TIS). Materials and Methods All dMR images in patients with TIS were collected from July 2009 to June 2017. Standardized signal intensity (sSI) was investigated, first using a lung aeration phantom to establish feasibility and sensitivity and then in a retrospective research study of 40 healthy children (16 male, 24 female; mean age, 9.6 years ± 2.1 [SD]), 20 patients with TIS before and after surgery (11 male, nine female; mean age, 6.2 years ± 4.2), and another 10 healthy children who underwent repeated dMRI examinations (seven male, three female; mean age, 9 years ± 3.6). Individual lungs in 4D dMR images were segmented, and sSI was assessed for each lung at end expiration (EE), at end inspiration (EI), preoperatively, postoperatively, in comparison to normal lungs, and in repeated scans. Results Air content changes of approximately 6% were detectable in phantoms via sSI. sSI within phantoms significantly correlated with air occupation (Pearson correlation coefficient = -0.96 [P < .001]). For healthy children, right lung sSI was significantly lower than that of left lung sSI (at EE: 41 ± 6 vs 47 ± 6 and at EI: 39 ± 6 vs 43 ± 7, respectively; P < .001), lung sSI at EI was significantly lower than that at EE (P < .001), and left lung sSI at EE linearly decreased with age (r = -0.82). Lung sSI at EE and EI decreased after surgery for patients (although not statistically significantly, with P values of sSI before surgery vs sSI after surgery, left and right lung separately, in the range of 0.13-0.51). sSI varied within 1.6%-4.7% between repeated scans. Conclusion This study demonstrates the feasibility of detecting change in sSI in phantoms via bright-blood dMRI when air occupancy changes. The observed reduction in average lung sSI after surgery in pediatric patients with TIS may indicate postoperative improvement in parenchymal aeration. Keywords: MR Imaging, Thorax, Lung, Pediatrics, Thoracic Surgery, Lung Parenchymal Aeration, Free-breathing Dynamic MRI, MRI Intensity Standardization, Thoracic Insufficiency Syndrome Supplemental material is available for this article. © RSNA, 2024.
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Pulmão , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Humanos , Masculino , Feminino , Criança , Imageamento por Ressonância Magnética/métodos , Pulmão/diagnóstico por imagem , Estudos Retrospectivos , Insuficiência Respiratória/diagnóstico por imagem , Respiração , Síndrome , Pré-Escolar , Imageamento Tridimensional/métodosRESUMO
Bisphenol M (BPM), an alternative to bisphenol A (BPA), is commonly utilized in various industrial applications. However, BPM does not represent a safe substitute for BPA due to its detrimental effects on living beings. This research aimed to assess the influence of BPM exposure on the in vitro maturation of mouse oocytes. The findings revealed that BPM exposure had a notable impact on the germinal vesicle breakdown (GVBD) rate and polar body extrusion (PBE) rate throughout the meiotic progression of mouse oocytes, ultimately resulting in meiotic arrest. Investigations demonstrated that oocytes exposure to BPM led to continued activation of spindle assembly checkpoint. Further studies revealed that securin and cyclin B1 could not be degraded in BPM-exposed oocytes, and meiosis could not realize the transition from the MI to the AI stage. Mechanistically, BPM exposure resulted in abnormal spindle assembly and disrupted chromosome alignment of oocytes. Additionally, abnormal positioning of microtubule organizing center-associated proteins implied that MTOC may be dysfunctional. Furthermore, an elevation in the acetylation level of α-tubulin in oocytes was observed after BPM treatment, leading to decreased microtubule stability. In addition to its impact on microtubules, BPM exposure led to a reduction in the expression of the actin, signifying the disruption of actin assembly. Further research indicated a heightened incidence of DNA damage in oocytes following BPM exposure. Besides, BPM exposure induced alterations in histone modifications. The outcomes of this experiment demonstrate that BPM exposure impairs oocyte quality and inhibits meiotic maturation of mouse oocytes.
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Compostos Benzidrílicos , Citoesqueleto , Meiose , Oócitos , Fenóis , Animais , Oócitos/efeitos dos fármacos , Fenóis/toxicidade , Feminino , Compostos Benzidrílicos/toxicidade , Citoesqueleto/efeitos dos fármacos , Meiose/efeitos dos fármacos , Camundongos , Ciclo Celular/efeitos dos fármacos , Técnicas de Maturação in Vitro de Oócitos , Fuso Acromático/efeitos dos fármacos , Oogênese/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Camundongos Endogâmicos ICRRESUMO
Sirtuin 5 (Sirt5), a member of the Sirtuin family, is involved in various intracellular biological processes. However, the function of Sirt5 in oocyte maturation has not been clearly elucidated. In this study, we observed that Sirt5 was persistently expressed during the meiotic division of mouse oocytes, with a notable decline in expression in aging oocytes. Sirt5 inhibition led to the failure of the first polar body extrusion and induced cell cycle arrest, indicative of unsuccessful oocyte maturation. Furthermore, Sirt5 inhibition was associated with the extrusion of abnormally large polar bodies, suggesting disrupted asymmetric oocyte division. Mechanistically, the inhibition of Sirt5 resulted in aberrant spindle assembly and disordered chromosome alignment in oocytes. Moreover, Sirt5 inhibition caused the spindle to be centrally located in the oocyte without migrating to the cortical region, consequently preventing the formation of the actin cap. Further investigation revealed that Sirt5 inhibition notably diminished the expression of phosphorylated cofilin and profilin1, while increasing cytoplasmic F-actin levels. These findings suggest that Sirt5 inhibition during oocyte maturation adversely affects spindle assembly and chromosome alignment and disrupts actin dynamics impairing spindle migration and contributing to the failure of symmetric oocyte division and maturation.
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5-Aminolevulinic acid (5-ALA) is a non-proteinogenic amino acid essential for synthesizing tetrapyrrole compounds, including heme, chlorophyll, cytochrome, and vitamin B12. As a plant growth regulator, 5-ALA is extensively used in agriculture to enhance crop yield and quality. The complexity and low yield of chemical synthesis methods have led to significant interest in the microbial synthesis of 5-ALA. Advanced strategies, including the: enhancement of precursor and cofactor supply, compartmentalization of key enzymes, product transporters engineering, by-product formation reduction, and biosensor-based dynamic regulation, have been implemented in bacteria for 5-ALA production, significantly advancing its industrialization. This article offers a comprehensive review of recent developments in 5-ALA production using engineered bacteria and presents new insights to propel the field forward.
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Background: The diaphragm is a critical structure in respiratory function, yet in-vivo quantitative description of its motion available in the literature is limited. Research Question: How to quantitatively describe regional hemi-diaphragmatic motion and curvature via free-breathing dynamic magnetic resonance imaging (dMRI)? Study Design and Methods: In this prospective cohort study we gathered dMRI images of 177 normal children and segmented hemi-diaphragm domes in end-inspiration and end-expiration phases of the constructed 4D image. We selected 25 points uniformly located on each 3D hemi-diaphragm surface. Based on the motion and local shape of hemi-diaphragm at these points, we computed the velocities and sagittal and coronal curvatures in 13 regions on each hemi-diaphragm surface and analyzed the change in these properties with age and gender. Results: Our cohort consisted of 94 Females, 6-20 years (12.09 + 3.73), and 83 Males, 6-20 years (11.88 + 3.57). We observed velocity range: â¼2mm/s to â¼13mm/s; Curvature range -Sagittal: â¼3m -1 to â¼27m -1 ; Coronal: â¼6m -1 to â¼20m -1 . There was no significant difference in velocity between genders, although the pattern of change in velocity with age was different for the two groups. Strong correlations in velocity were observed between homologous regions of right and left hemi-diaphragms. There was no significant difference in curvatures between genders or change in curvatures with age. Interpretation: Regional motion/curvature of the 3D diaphragmatic surface can be estimated using free-breathing dynamic MRI. Our analysis sheds light on here-to-fore unknown matters such as how the pediatric 3D hemi-diaphragm motion/shape varies regionally, between right and left hemi-diaphragms, between genders, and with age.
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Purpose: There is a concern in pediatric surgery practice that rib-based fixation may limit chest wall motion in early onset scoliosis (EOS). The purpose of this study is to address the above concern by assessing the contribution of chest wall excursion to respiration before and after surgery. Methods: Quantitative dynamic magnetic resonance imaging (QdMRI) is performed on EOS patients (before and after surgery) and normal children in this retrospective study. QdMRI is purely an image-based approach and allows free breathing image acquisition. Tidal volume parameters for chest walls (CWtv) and hemi-diaphragms (Dtv) were analyzed on concave and convex sides of the spinal curve. EOS patients (1-14 years) and normal children (5-18 years) were enrolled, with an average interval of two years for dMRI acquisition before and after surgery. Results: CWtv significantly increased after surgery in the global comparison including all EOS patients (p < 0.05). For main thoracic curve (MTC) EOS patients, CWtv significantly improved by 50.24% (concave side) and 35.17% (convex side) after age correction (p < 0.05) after surgery. The average ratio of Dtv to CWtv on the convex side in MTC EOS patients was not significantly different from that in normal children (p=0.78), although the concave side showed the difference to be significant. Conclusion: Chest wall component tidal volumes in EOS patients measured via QdMRI did not decrease after rib-based surgery, suggesting that rib-based fixation does not impair chest wall motion in pediatric patients with EOS.