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1.
J Clin Neurol ; 20(4): 439-449, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38951977

RESUMO

BACKGROUND AND PURPOSE: Migraine is a condition that is often observed to run in families, but its complex genetic background remains unclear. This study aimed to identify the genetic factors influencing migraines and their potential association with the family medical history. METHODS: We performed a comprehensive genome-wide association study of a cohort of 1,561 outpatients with migraine and 473 individuals without migraine in Taiwan, including Han Chinese individuals with or without a family history of migraine. By analyzing the detailed headache history of the patients and their relatives we aimed to isolate potential genetic markers associated with migraine while considering factors such as sex, episodic vs. chronic migraine, and the presence of aura. RESULTS: We revealed novel genetic risk loci, including rs2287637 in DEAD-Box helicase 1 and long intergenic non-protein coding RNA 1804 and rs12055943 in engulfment and cell motility 1, that were correlated with the family history of migraine. We also found a genetic location downstream of mesoderm posterior BHLH transcription factor 2 associated with episodic migraine, whereas loci within the ubiquitin-specific peptidase 26 exonic region, dual specificity phosphatase 9 and pregnancy-upregulated non-ubiquitous CaM kinase intergenic regions, and poly (ADP-ribose) polymerase 1 and STUM were linked to chronic migraine. We additionally identified genetic regionsassociated with the presence or absence of aura. A locus between LINC02561 and urocortin 3 was predominantly observed in female patients. Moreover, three different single-nucleotide polymorphisms were associated with the family history of migraine in the control group. CONCLUSIONS: This study has identified new genetic locations associated with migraine and its family history in a Han Chinese population, reinforcing the genetic background of migraine. The findings point to potential candidate genes that should be investigated further.

2.
J Environ Manage ; 367: 122005, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39079485

RESUMO

Soil organic carbon and nitrogen play pivotal roles as indicators of soil quality and ecological functioning in wetlands. The escalating impact of human activities and climate change has led to a severe degradation of wetland soils, particularly in semi-arid regions. However, an understanding of the factors governing the dynamics of total soil organic carbon (TSOC) and total soil nitrogen (TSN) in semi-arid areas remains elusive, impeding a comprehensive understanding of wetland ecological functions. The present study investigated variations in TSOC and TSN content as well as vegetation and soil physicochemical properties under five different land management practices (mowed wetlands, mowed and slightly grazed wetlands, moderately grazed wetlands, heavily grazed wetlands, and natural wetlands unaffected by human interference) in the semi-arid Songnen Plain region of China. The results revealed significant decreases in TSOC and TSN content within managed wetlands compared to natural wetlands. Moreover, positive correlations were observed between pairs of SOC-TN or their storage values for SOC (TSOC)-TN (TSN). Furthermore, TSOC and TSN exhibited significant positive associations with aboveground and belowground biomass levels, stem C:N, stem C:P, soil C:P, and soil N:P. Additionally, redundancy analysis indicated that species diversity accounted for 37.4% of the variations in TSOC-TSN while belowground biomass accounted for 8.5% of the variations. Furthermore, nutrient content within stems (particularly N content and C:P) contributed to a 37.2% variation in TSOC and TSN whereas root nutrient content (especially N:P, C:N, and C:P) contributed to a 15.3% variation. Soil C:P, C:N, and total phosphorous (TP) content accounted for 65.7%, 9.6%, and 7.5% of variations of TSOC and TSN, respectively. Besides, variation partitioning analysis revealed that plant community characteristics, community nutrient content, and soil physicochemical properties collectively influenced the dynamics of TSOC and TSN. Among these factors, soil physicochemical properties emerged as the primary drivers of carbon and nitrogen dynamics in degraded wetlands in semi-arid regions. The impact on TSN was more pronounced than that of TSOC. This study provides valuable insights for understanding the processes and mechanisms underlying carbon and nitrogen accumulation in degraded wetlands, facilitating the development of regionally adaptive management plans under different management practices.

3.
IEEE Trans Biomed Eng ; PP2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39074001

RESUMO

OBJECTIVE: Multi-color Magnetic Particle Imaging (MPI) technology offers high sensitivity and non-invasive imaging capabilities. It can simultaneously image multiple superparamagnetic iron oxide nanoparticles (SPIOs), facilitating more precise detection of multiple molecular markers in vivo. However, the fixed drive frequency of existing hand-held MPI devices makes it difficult to fully match the nonlinear magnetic response of different SPIOs, affecting the spatial resolution and quantitative accuracy of multi-color imaging. METHODS: We designed a novel rapid frequency conversion based hand-held multi-color magnetic particle imaging (RFC-MPI) device. This device adjusts the drive frequency based on the nonlinear magnetic response of SPIOs at different frequencies, effectively expanding the system matrix information and thereby improving spatial resolution and multi-color imaging capabilities simultaneously. RESULTS: The device achieved a spatial resolution of 2 mm and an imaging speed of 1 frame/s. The scanning depth is 8 mm. It was used to scan a 22 cm x 22 cm area of a human-shaped phantom, verifying its potential for scanning humans. The ability of the device to identify and quantify SPIOs was validated using mice breast tumors. The quantitative accuracy during simultaneous imaging was determined to be 96.58%. CONCLUSION: Due to its innovative structural design and rapid frequency conversion method, the RFC-MPI device exhibits excellent in vivo imaging performance. Both simulation and phantom experiments have verified the effectiveness of the proposed method. SIGNIFICANCE: The hand-held RFC-MPI device can effectively improve the spatial resolution and quantitative accuracy of multi-color MPI, laying the foundation for future clinical applications.

4.
Microbiol Spectr ; : e0010824, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39041812

RESUMO

Aspergillus flavus conidia are widespread in air; they attach to food and feed crops and secrete aflatoxins, which results in serious contamination. Germination of A. flavus conidia is the most critical step in contamination of food by A. flavus. This study aims to gain an insight into A. flavus conidia through dormancy to germination to provide a theoretical basis for inhibition of A. flavus conidia germination. The morphological changes and regulation mechanism of A. flavus conidia germination at 0, 4, 8, and 12 hours were observed. Transcriptomic and metabolomic analyses showed that conidia became active from dormancy (0 hour) to the initial stage of germination (4 hours), cellular respiration and energy metabolism increased, and amino acids and lipids were synthesized rapidly. The number of differentially expressed genes and differential metabolites was highest at this stage. Besides, we found that conidia germination had selectivity for different carbon and nitrogen sources. Compared with monosaccharides, disaccharides, as the only carbon source, significantly promoted the germination of conidia. Moreover, MepA, one of genes in the ammonium transporter family was studied. The gene deletion mutant ΔMepA had a significant growth defect, and the expression of MeaA was significantly upregulated in ΔMepA compared with the wild-type, indicating that both MepA and MeaA played an important role in transporting ammonium ions.IMPORTANCEThis is the first study to use combined transcriptomic and metabolomics analyses to explore the biological changes during germination of Aspergillus flavus conidia. The biological process with the highest changes occurred in 0-4 hours at the initial stage of germination. Compared with polysaccharides, monosaccharides significantly increased the size of conidia, while significantly decreasing the germination rate of conidia. Both MeaA and MepA were involved in ammonia transport and metabolism during conidia germination.

5.
STAR Protoc ; 5(2): 103042, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38850537

RESUMO

The mitochondrial stress test is a gold-standard approach for assessing adipose tissue physiological functions and pathological changes. Here, we present a protocol for conducting Seahorse assays using ex vivo mouse brown and white adipose depots. We describe steps for rehydrating the cartridge, preparing freshly harvested fat depots, placing them onto an islet capture plate, and incubating them in a non-CO2 incubator. We then detail procedures for adding mitochondrial stressor solutions and conducting the mitochondrial stress test using the Seahorse XFe24 Analyzer. For complete details on the use and execution of this protocol, please refer to An et al.1.


Assuntos
Tecido Adiposo Marrom , Tecido Adiposo Branco , Mitocôndrias , Animais , Camundongos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Marrom/metabolismo , Mitocôndrias/metabolismo
6.
J Environ Manage ; 362: 121286, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38824886

RESUMO

Water deficiency threatens the health and function of wetlands in semi-arid areas. Optimum re-watering is an effective method for close-to-natural restoration to mitigate wetland degradation. Although the ecological importance of optimal re-watering as a nature-based solution for promoting wetland plant growth has been widely recognized, the response mechanisms of seed germination and seedling growth to re-watering are still poorly understood despite their decisive impact on plant life history. To fill this gap, this study compared the characteristics of seed germination and seedling growth in Carex schmidtii under initial water content with three levels (30%, 50%, and 70%) and five re-watering treatments (maintained at constant water content and re-watering to 100% on 7th, 14th, 21st, and 28th day). Moreover, the degree of reserve mobilization during four germination stages (seed suckering, sprouting, 20% germination, and seedling growth) was investigated. The results showed that water deficiency and re-watering treatments significantly affected C. schmidtii seed germination, seedling growth, and reserve mobilization. Compared with the other treatments, 50% moisture content and re-watering to 100% on the 14th day (50%-RT3) treatment significantly improved germination traits (germination rate, daily germination rate, germination index, and vigor index) and seedling growth characteristics (shoot length, root length, shoot biomass, root biomass, and total biomass). Furthermore, the degree of mobilization of starch, soluble protein, fat, and soluble sugar accumulation in C. schmidtii seeds under 50%-RT3 was higher than that in the other treatments. The structural equation model showed that the characteristics of seed germination and seedling growth of C. schmidtii were directly related to water deficiency and re-watering treatments, whereas reserve mobilization indirectly affected seed germination and seedling growth. These findings demonstrated that water deficiency and re-watering treatments have a crucial regulatory effect on seed germination and seedling growth of wetland plant species through a dual mechanism. This study provides information for the formulation of an optimum re-watering strategy for wetland vegetation restoration in semi-arid areas of the world.


Assuntos
Germinação , Plântula , Sementes , Água , Áreas Alagadas , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento
7.
Comput Biol Med ; 178: 108783, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38909446

RESUMO

Magnetic particle imaging (MPI) is an emerging non-invasive medical imaging tomography technology based on magnetic particles, with excellent imaging depth penetration, high sensitivity and contrast. Spatial resolution and signal-to-noise ratio (SNR) are key performance metrics for evaluating MPI, which are directly influenced by the gradient of the selection field (SF). Increasing the SF gradient can improve the spatial resolution of MPI, but will lead to a decrease in SNR. Deep learning (DL) methods may enable obtaining high-resolution images from low-resolution images to improve the MPI resolution under low gradient conditions. However, existing DL methods overlook the physical procedures contributing to the blurring of MPI images, resulting in low interpretability and hindering breakthroughs in resolution. To address this issue, we propose a dual-channel end-to-end network with prior knowledge embedding for MPI (DENPK-MPI) to effectively establish a latent mapping between low-gradient and high-gradient images, thus improving MPI resolution without compromising SNR. By seamlessly integrating MPI PSF with DL paradigm, DENPK-MPI leads to a significant improvement in spatial resolution performance. Simulation, phantom, and in vivo MPI experiments have collectively confirmed that our method can improve the resolution of low-gradient MPI images without sacrificing SNR, resulting in a decrease in full width at half maximum by 14.8%-23.8 %, and the accuracy of image reconstruction is 18.2 %-27.3 % higher than other DL methods. In conclusion, we propose a DL method that incorporates MPI prior knowledge, which can improve the spatial resolution of MPI without compromising SNR and possess improved biomedical application.


Assuntos
Processamento de Imagem Assistida por Computador , Imagens de Fantasmas , Razão Sinal-Ruído , Processamento de Imagem Assistida por Computador/métodos , Animais , Camundongos , Aprendizado Profundo , Humanos , Nanopartículas de Magnetita/química , Tomografia/métodos
8.
Biology (Basel) ; 13(6)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38927248

RESUMO

The purpose of this study was to explore the effects of Res and EGCG on cell growth, cellular antioxidant levels, and cellular lipid metabolism in hepatocytes. In this experiment, leghorn male hepatoma (LMH) cells were used as hepatocytes. The results showed that 6.25-25 µM Res and EGCG had no adverse effects on cell viability and growth. Meanwhile, with the increasing dosage of Res and EGCG, the contents of total cholesterol (TC), total glyceride (TG), and malondialdehyde (MDA) in hepatocytes decreased significantly (p < 0.05), while the contents of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), and catalase (CAT) increased significantly (p < 0.05). In addition, western blot results showed that Res and EGCG could significantly increase the expression of p-AMPK protein and reduce the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) protein in hepatocytes (p < 0.05). Moreover, q-PCR results showed that with the increase in Res and EGCG, the expression of cholesterol- and fatty acid synthesis-related genes decreased significantly (p < 0.05). In conclusion, Res and EGCG can increase the antioxidant capacity of hepatocytes and reduce the synthesis of TC and TG in hepatocytes by activating AMPK, thereby regulating lipid metabolism in hepatocytes.

9.
Exp Neurol ; 378: 114823, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38782351

RESUMO

The established role of disturbances in the microbiota-gut-brain axis in the development of diabetic cognitive impairment (DCI) has long been recognized. It has shown the potential of Akkermansia muciniphila (A. muciniphila) in improving metabolic disorders and exerting anti-inflammatory effects. However, there remains a lack of comprehensive understanding regarding the specific effects and mechanisms underlying the treatment of DCI with A. muciniphila. This study aimed to evaluate the potential of A. muciniphila in alleviating DCI in db/db mice. Eleven-week-old db/db mice were administered either live or pasteurized A. muciniphila (5 × 109 CFU/200 µL) for a duration of eight weeks. Administering live A. muciniphila significantly ameliorated cognitive impairments, improved the synaptic ultrastructure, and inhibited hippocampal neuron loss in the CA1 and CA3 subregions in db/db mice. Both live and pasteurized A. muciniphila effectively mitigated neuroinflammation. Moreover, live A. muciniphila increased the relative abundance of Lactococcus and Staphylococcus, whereas pasteurized A. muciniphila increased the relative abundance of Lactobacillus, Prevotellaceae_UCG_001, and Alistipes. Supplementation of A. muciniphila also induced alterations in serum and brain metabolites, with a particular enrichment observed in tryptophan metabolism, glyoxylate and dicarboxylate metabolism, nitrogen metabolism, and pentose and glucuronate interconversions. Correlation analysis further demonstrated a direct and substantial correlation between the altered gut microbiota and the metabolites in the serum and brain tissue. In conclusion, the results indicate that live A. muciniphila demonstrated greater efficacy compared to pasteurized A. muciniphila. The observed protective effects of A. muciniphila against DCI are likely mediated through the neuroinflammation and microbiota-metabolites-brain axis.


Assuntos
Akkermansia , Disfunção Cognitiva , Microbioma Gastrointestinal , Probióticos , Animais , Microbioma Gastrointestinal/fisiologia , Camundongos , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/dietoterapia , Disfunção Cognitiva/etiologia , Masculino , Probióticos/farmacologia , Probióticos/uso terapêutico , Verrucomicrobia , Camundongos Endogâmicos C57BL , Pasteurização
10.
Mol Cell Biochem ; 479(7): 1707-1720, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38822192

RESUMO

HOXC6 (Homeobox C6) and methyltransferase-like 3 (METTL3) have been shown to be involved in the progression of prostate cancer (PCa). However, whether HOXC6 performs oncogenic effects in PCa via METTL3-mediated N6-methyladenosine (m6A) modification is not yet reported. The Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, scratch, sphere formation assays were applied for cell growth, invasion, migration and stemness analyses. Glycolysis was evaluated by measuring glucose consumption, lactate generation and ATP/ADP ratio. The N6-methyladenine (m6A) modification profile was determined by RNA immunoprecipitation (Me-RIP) assay. The proteins that interact with PGK1 (phosphoglycerate kinase 1) were confirmed by Co-immunoprecipitation assay. Tumor formation experiments in mice were conducted for in vivo assay. PCa tissues and cells showed highly expressed HOXC6 and METTL3. Functionally, the silencing of HOXC6 or METTL3 suppresses PCa cell proliferation, invasion, migration, stemness, and glycolysis. Moreover, METTL3-induced HOXC6 m6A modification to stabilize its expression. In addition, the m6A reader IGF2BP2 directly recognized and bound to HOXC6 mRNA, and maintained its stability, and was involved in the regulation of HOXC6 expression by METTL3. Furthermore, IGF2BP2 knockdown impaired PCa cell proliferation, invasion, migration, stemness, and glycolysis by regulating HOXC6. Besides that HOXC6 interacted with the glycoytic enzyme PGK1 in PCa cells. In vivo assays further showed that METTL3 silencing reduced the expression of HOXC6 and PGK1, and impeded PCa growth. METTL3 promoted PCa progression by maintaining HOXC6 expression in an m6A-IGF2BP2-dependent mechanism.


Assuntos
Adenosina , Proteínas de Homeodomínio , Metiltransferases , Neoplasias da Próstata , Proteínas de Ligação a RNA , Metiltransferases/metabolismo , Metiltransferases/genética , Masculino , Humanos , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Neoplasias da Próstata/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Animais , Camundongos , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Adenosina/análogos & derivados , Adenosina/metabolismo , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Progressão da Doença , Fosfoglicerato Quinase/metabolismo , Fosfoglicerato Quinase/genética , Linhagem Celular Tumoral , Glicólise , Movimento Celular , Camundongos Nus
11.
Alzheimers Res Ther ; 16(1): 106, 2024 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-38730474

RESUMO

BACKGROUND: Previous studies on the associations between serum urate levels and neurodegenerative outcomes have yielded inconclusive results, and the causality remains unclear. This study aimed to investigate whether urate levels are associated with the risks of Alzheimer's disease and related dementias (ADRD), Parkinson's disease (PD), and neurodegenerative deaths. METHODS: This prospective study included 382,182 participants (45.7% men) from the UK Biobank cohort. Cox proportional hazards models were used to assess the associations between urate levels and risk of neurodegenerative outcomes. In the Mendelian randomization (MR) analysis, urate-related single-nucleotide polymorphisms were identified through a genome-wide association study. Both linear and non-linear MR approaches were utilized to investigate the potential causal associations. RESULTS: During a median follow-up period of 12 years, we documented 5,400 ADRD cases, 2,553 PD cases, and 1,531 neurodegenerative deaths. Observational data revealed that a higher urate level was associated with a decreased risk of ADRD (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.90, 0.96), PD (HR: 0.87, 95% CI: 0.82, 0.91), and neurodegenerative death (HR: 0.88, 95% CI: 0.83, 0.94). Negative linear associations between urate levels and neurodegenerative events were observed (all P-values for overall < 0.001 and all P-values for non-linearity > 0.05). However, MR analyses yielded no evidence of either linear or non-linear associations between genetically predicted urate levels and the risk of the aforementioned neurodegenerative events. CONCLUSION: Although the prospective cohort study demonstrated that elevated urate levels were associated with a reduced risk of neurodegenerative outcomes, MR analyses found no evidence of causality.


Assuntos
Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Polimorfismo de Nucleotídeo Único , Ácido Úrico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Alzheimer/genética , Doença de Alzheimer/sangue , Doença de Alzheimer/epidemiologia , Estudos de Coortes , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/sangue , Doenças Neurodegenerativas/epidemiologia , Doença de Parkinson/genética , Doença de Parkinson/sangue , Doença de Parkinson/epidemiologia , Estudos Prospectivos , Biobanco do Reino Unido , Reino Unido/epidemiologia , Ácido Úrico/sangue
12.
Nutrients ; 16(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38732503

RESUMO

(1) Background: This study investigated the effects of caffeinated chewing gum on the basketball-specific performance of trained basketball players. A double-blind, randomized crossover design was employed. (2) Methods: Fifteen participants (age: 20.9 ± 1.0 years; height: 180.9 ± 5.4 cm; mass: 77.2 ± 7.5 kg; training age: 8.2 ± 0.3 years) were recruited and divided into a caffeine trial (CAF) and placebo trial (PL). The participants in the CAF trial chewed gum containing 3 mg/kg of caffeine for 10 min, while those in the PL trial chewed a placebo gum without caffeine. Following a 15 min rest, all the participants completed basketball-specific performance tests. (3) Results: The free throw accuracy for the CAF trial was significantly higher than that for the PL trial (CAF: 79.0 ± 4.31%; PL: 73.0 ± 9.16%; p = 0.012; Cohen's d = 0.94). Additionally, the CAF trial demonstrated significantly better performance in the 20 m segmented dash (CAF: 2.94 ± 1.12 s; PL: 3.13 ± 0.10 s; p < 0.001; Cohen's d =1.8) and squats (p < 0.05), and exhibited lower fatigue indexes (CAF: 3.6 ± 1.6%; PL: 5.2 ± 1.6%; p = 0.009; Cohen's d =1.0). (4) Conclusions: These findings suggest that chewing gum containing 3 mg/kg of caffeine offers moderate-to-large improvements in key performance aspects relevant to professionally trained basketball players.


Assuntos
Desempenho Atlético , Basquetebol , Cafeína , Goma de Mascar , Estudos Cross-Over , Humanos , Basquetebol/fisiologia , Método Duplo-Cego , Cafeína/administração & dosagem , Desempenho Atlético/fisiologia , Adulto Jovem , Masculino , Adulto , Atletas , Estimulantes do Sistema Nervoso Central/administração & dosagem , Estimulantes do Sistema Nervoso Central/farmacologia
13.
Clin Exp Gastroenterol ; 17: 141-145, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38708059

RESUMO

This report presents a unique case of acute necrotizing pancreatitis(ANP) concomitant with paroxysmal nocturnal hemoglobinuria(PNH), a combination that has not been documented in existing literature. The impact of PNH on ANP and its treatment remains uncertain due to the lack of consensus. The case described herein involves a patient who exhibited both ANP and PNH, subsequently experiencing splanchnic vein thrombosis (SVT), resulting in substantial intra-abdominal and gastrointestinal hemorrhaging. We attempted to analyze the role of PNH in the formation of SVT in ANP and propose some new insights and hypotheses for the treatment of such patients.

14.
IEEE Trans Biomed Eng ; PP2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739521

RESUMO

OBJECTIVE: Magnetic Particle Imaging (MPI) is a radiation-free tracer-based imaging technology that visualizes the spatial distribution of superparamagnetic iron oxide nanoparticles. Conventional spatial encoding methods in MPI rely on a gradient magnetic field with a constant gradient strength to generate a field-free point or line for spatial scanning. However, increasing the gradient strength can enhance theoretical spatial resolution but also lead to a decrease in the Signal-to-Noise Ratio (SNR) and sensitivity of the imaging system. This poses a technical challenge in balancing spatial resolution and sensitivity, necessitating intricate hardware design. METHODS: To address this, we present a Space-Specific Mixing Excitation (SSME) technique for achieving high-SNR spatial encoding in MPI. By utilizing a dual-frequency excitation magnetic field with a non-homogeneous field strength, magnetic particles at each position generate unique intermodulation responses. By performing multi-channel acquisitions across the entire field of view, high SNR MPI signals can be acquired. When combined with reconstruction techniques based on system matrix, multi-dimensional SSME-MPI can be achieved. RESULTS: The effectiveness of the proposed method was validated through phantom and in vivo imaging experiments. The results demonstrate significant improvements in sensitivity (3.6-fold improvement) and spatial resolution (better than 1 mm) without any hardware modifications. CONCLUSION: These findings demonstrate the capability of SSME to enhance both the spatial resolution and sensitivity of MPI. SIGNIFICANCE: This method provides a solution to the ongoing challenge of balancing spatial resolution and sensitivity in MPI, potentially facilitating the implementation of MPI in a wider range of medical applications.

15.
Med Phys ; 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38700948

RESUMO

BACKGROUND: Magnetic particle imaging (MPI) is a recently developed, non-invasive in vivo imaging technique to map the spatial distribution of superparamagnetic iron oxide nanoparticles (SPIONs) in animal tissues with high sensitivity and speed. It is a challenge to reconstruct images directly from the received signals of MPI device due to the complex physical behavior of the nanoparticles. System matrix and X-space are two commonly used MPI reconstruction methods, where the former is extremely time-consuming and the latter usually produces blurry images. PURPOSE: Currently, we proposed an end-to-end machine learning framework to reconstruct high-resolution MPI images from 1-D voltage signals directly and efficiently. METHODS: The proposed framework, which we termed "MPIGAN", was trained on a large MPI simulation dataset containing 291 597 pairs of high-resolution 2-D phantom images and each image's corresponding voltage signals, so that it was able to accurately capture the nonlinear relationship between the spatial distribution of SPIONs and the received voltage signal, and realized high-resolution MPI image reconstruction. RESULTS: Experiment results showed that, MPIGAN exhibited remarkable abilities in high-resolution MPI image reconstruction. MPIGAN outperformed the traditional methods of system matrix and X-space in recovering the fine-scale structure of magnetic nanoparticles' spatial distribution and achieving enhanced reconstruction performance in both visual effects and quantitative assessments. Moreover, even when the received signals were severely contaminated with noise, MPIGAN could still generate high-quality MPI images. CONCLUSION: Our study provides a promising AI solution for end-to-end, efficient, and high-resolution magnetic particle imaging reconstruction.

16.
IEEE Trans Med Imaging ; PP2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38781069

RESUMO

Open-sided magnetic particle imaging (OS-MPI) has garnered significant interest due to its potential for interventional applications. However, the system matrix calibration in OS-MPI using sequential scans is a time-consuming task and susceptible to the low signal-to-noise ratio (SNR) resulting from the small calibration sample size. These challenges have hindered the practical implementation of system matrix-based reconstruction for sequentially scanned OS-MPI. To address these issues, we propose a novel calibration method, named sequential scan-based single-dimension multi-voxel calibration (SS-SDMVC), to efficiently obtain a high-SNR system matrix. This method was implemented in a cylindrical field of view (FOV), where a bar calibration sample parallel to the field-free line (FFL) was shifted along a fixed radial direction. A standard image reconstruction process was also introduced to verify the feasibility of SS-SDMVC. Through simulations, we analyzed the effects of noise levels and scanner imperfections on the SS-SDMVC-based reconstruction and demonstrated its robustness. In experiments, we compared the imaging performance of SS-SDMVC and the sequential scan-based traditional cubic-FOV SMC. The results showed that SS-SDMVC reduced the number of measurements by a factor of 210.94 and achieved higher reconstruction quality. Therefore, SS-SDMVC is expected to improve the reconstruction quality of human-scale or high-gradient FFL MPI scanners.

17.
JCI Insight ; 9(10)2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775156

RESUMO

Since its emergence, SARS-CoV-2 has been continuously evolving, hampering the effectiveness of current vaccines against COVID-19. mAbs can be used to treat patients at risk of severe COVID-19. Thus, the development of broadly protective mAbs and an understanding of the underlying protective mechanisms are of great importance. Here, we isolated mAbs from donors with breakthrough infection with Omicron subvariants using a single-B cell screening platform. We identified a mAb, O5C2, which possesses broad-spectrum neutralization and antibody-dependent cell-mediated cytotoxic activities against SARS-CoV-2 variants, including EG.5.1. Single-particle analysis by cryo-electron microscopy revealed that O5C2 targeted an unusually large epitope within the receptor-binding domain of spike protein that overlapped with the angiotensin-converting enzyme 2 binding interface. Furthermore, O5C2 effectively protected against BA.5 Omicron infection in vivo by mediating changes in transcriptomes enriched in genes involved in apoptosis and interferon responses. Our findings provide insights into the development of pan-protective mAbs against SARS-CoV-2.


Assuntos
Anticorpos Antivirais , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , SARS-CoV-2/imunologia , Humanos , COVID-19/imunologia , COVID-19/virologia , Anticorpos Antivirais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/química , Animais , Camundongos , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Microscopia Crioeletrônica , Epitopos/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Feminino
18.
Sci Adv ; 10(22): eadl1123, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38809977

RESUMO

Immunosenescence contributes to systematic aging and plays a role in the pathogenesis of Alzheimer's disease (AD). Therefore, the objective of this study was to investigate the potential of immune rejuvenation as a therapeutic strategy for AD. To achieve this, the immune systems of aged APP/PS1 mice were rejuvenated through young bone marrow transplantation (BMT). Single-cell RNA sequencing revealed that young BMT restored the expression of aging- and AD-related genes in multiple cell types within blood immune cells. The level of circulating senescence-associated secretory phenotype proteins was decreased following young BMT. Notably, young BMT resulted in a significant reduction in cerebral Aß plaque burden, neuronal degeneration, neuroinflammation, and improvement of behavioral deficits in aged APP/PS1 mice. The ameliorated cerebral amyloidosis was associated with an enhanced Aß clearance of peripheral monocytes. In conclusion, our study provides evidence that immune system rejuvenation represents a promising therapeutic approach for AD.


Assuntos
Doença de Alzheimer , Modelos Animais de Doenças , Rejuvenescimento , Animais , Doença de Alzheimer/terapia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/imunologia , Camundongos , Camundongos Transgênicos , Transplante de Medula Óssea , Comportamento Animal , Peptídeos beta-Amiloides/metabolismo , Monócitos/imunologia , Monócitos/metabolismo , Placa Amiloide/patologia , Placa Amiloide/metabolismo , Envelhecimento/imunologia , Humanos
19.
Gut ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724220

RESUMO

OBJECTIVE: Previous studies indicate that eosinophils are recruited into the allograft following orthotopic liver transplantation and protect from ischaemia reperfusion (IR) injury. In the current studies, we aim to explore whether their protective function could outlast during liver repair. DESIGN: Eosinophil-deficient mice and adoptive transfer of bone marrow-derived eosinophils (bmEos) were employed to investigate the effects of eosinophils on tissue repair and regeneration after hepatic IR injury. Aside from exogenous cytokine or neutralising antibody treatments, mechanistic studies made use of a panel of mouse models of eosinophil-specific IL-4/IL-13-deletion, cell-specific IL-4rα-deletion in liver macrophages and hepatocytes and macrophage-specific deletion of heparin-binding epidermal growth factor-like growth factor (hb-egf). RESULT: We observed that eosinophils persisted over a week following hepatic IR injury. Their peak accumulation coincided with that of hepatocyte proliferation. Functional studies showed that eosinophil deficiency was associated with a dramatic delay in liver repair, which was normalised by the adoptive transfer of bmEos. Mechanistic studies demonstrated that eosinophil-derived IL-4, but not IL-13, was critically involved in the reparative function of these cells. The data further revealed a selective role of macrophage-dependent IL-4 signalling in liver regeneration. Eosinophil-derived IL-4 stimulated macrophages to produce HB-EGF. Moreover, macrophage-specific hb-egf deletion impaired hepatocyte regeneration after IR injury. CONCLUSION: Together, these studies uncovered an indispensable role of eosinophils in liver repair after acute injury and identified a novel crosstalk between eosinophils and macrophages through the IL-4/HB-EGF axis.

20.
Curr Med Sci ; 44(2): 399-405, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38632142

RESUMO

OBJECTIVE: Complete resection of malignant gliomas is often challenging. Our previous study indicated that intraoperative contrast-enhanced ultrasound (ICEUS) could aid in the detection of residual tumor remnants and the total removal of brain lesions. This study aimed to investigate the survival rates of patients undergoing resection with or without the use of ICEUS and to assess the impact of ICEUS on the prognosis of patients with malignant glioma. METHODS: A total of 64 patients diagnosed with malignant glioma (WHO grade HI and IV) who underwent surgery between 2012 and 2018 were included. Among them, 29 patients received ICEUS. The effects of ICEUS on overall survival (OS) and progression-free survival (PFS) of patients were evaluated. A quantitative analysis was performed to compare ICEUS parameters between gliomas and the surrounding tissues. RESULTS: The ICEUS group showed better survival rates both in OS and PFS than the control group. The univariate analysis revealed that age, pathology and ICEUS were significant prognostic factors for PFS, with only age being a significant prognostic factor for OS. In multivariate analysis, age and ICEUS were significant prognostic factors for both OS and PFS. The quantitative analysis showed that the intensity and transit time of microbubbles reaching the tumors were significantly different from those of microbubbles reaching the surrounding tissue. CONCLUSION: ICEUS facilitates the identification of residual tumors. Age and ICEUS are prognostic factors for malignant glioma surgery, and use of ICEUS offers a better prognosis for patients with malignant glioma.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Glioma/diagnóstico por imagem , Glioma/cirurgia , Ultrassonografia , Prognóstico , Análise de Sobrevida
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