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1.
DNA Cell Biol ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39049814

RESUMEN

The qseC gene is a two-component system that encodes a histidine protein kinase and is highly conserved among different Glaesserella parasuis strains. In this study, we used qRT-PCR and enzyme-linked immunosorbent assay to confirm that Toll-like receptor 4 (TLR4) plays a role in the expression of proinflammatory cytokines interleukin (IL)-1ß and IL-6 by stimulating RAW 264.7 macrophages with QseC. Furthermore, we revealed that blocking the p38 and NF-κB pathways that regulate signaling can significantly reduce the production of proinflammatory cytokines induced by QseC. In summary, our data suggest that QseC is a novel proinflammatory mediator that induces TLR4-dependent proinflammatory activity in RAW 264.7 macrophages through the p38 and NF-κB pathways.

2.
ACS Nano ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39041805

RESUMEN

Exogenous polysulfhydryls (R-SH) supplementation and nitric oxide (NO) gas molecules delivery provide essential antioxidant buffering pool components and anti-inflammatory species in cellular defense against injury, respectively. Herein, the intermolecular disulfide bonds in bovine serum albumin (BSA) molecules were reductively cleaved under native and mild conditions to expose multiple sulfhydryl groups (BSA-SH), then sulfhydryl-nitrosylated (R-SNO), and nanoprecipitated to form injectable self-sulfhydrated, nitro-fixed albumin nanoparticles (BSA-SNO NPs), allowing albumin to act as a NO donor reservoir and multiple sulfhydryl group transporter while also preventing unfavorable oxidation and self-cross-linking of polysulfhydryl groups. In two mouse models of ischemia/reperfusion-induced and endotoxin-induced acute liver injury (ALI), a single low dosage of BSA-SNO NPs (S-nitrosothiols: 4 µmol·kg-1) effectively attenuated oxidative stress and systemic inflammation cascades in the upstream pathophysiology of disease progression, thus rescuing dying hepatocytes, regulating host defense, repairing microcirculation, and restoring liver function. By mechanistically upregulating the antioxidative signaling pathway (Nrf-2/HO-1/NOQ1) and inhibiting the inflammatory cytokine storm (NF-κB/p-IκBα/TNF-α/IL-ß), BSA-SNO NPs blocked the initiation of the mitochondrial apoptotic signaling pathway (Cyto C/Bcl-2 family/caspase-3) and downregulated the cell pyroptosis pathway (NLRP3/ASC/IL-1ß), resulting in an increased survival rate from 26.7 to 73.3%. This self-sulfhydrated, nitro-fixed functionalized BSA nanoformulation proposes a potential drug-free treatment strategy for ALI.

3.
ACS Nano ; 18(29): 19283-19302, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38990194

RESUMEN

Developing strategies to target injured pancreatic acinar cells (PACs) in conjunction with primary pathophysiology-specific pharmacological therapy presents a challenge in the management of acute pancreatitis (AP). We designed and synthesized a trypsin-cleavable organosilica precursor bridged by arginine-based amide bonds, leveraging trypsin's ability to selectively identify guanidino groups on arginine via Asp189 at the active S1 pocket and cleave the carboxy-terminal (C-terminal) amide bond via catalytic triads. The precursors were incorporated into the framework of mesoporous silica nanoparticles (MSNs) for encapsulating the membrane-permeable Ca2+ chelator BAPTA-AM with a high loading content (∼43.9%). Mesenchymal stem cell membrane coating and surface modification with PAC-targeting ligands endow MSNs with inflammation recruitment and precise PAC-targeting abilities, resulting in the highest distribution at 3 h in the pancreas with 4.7-fold more accumulation than that of naked MSNs. The outcomes transpired as follows: After bioinspired MSNs' skeleton biodegradation by prematurely and massively activated trypsin, BAPTA-AM was on-demand released in injured PACs, thereby effectively eliminating intracellular calcium overload (reduced Ca2+ level by 81.3%), restoring cellular redox status, blocking inflammatory cascades, and inhibiting cell necrosis by impeding the IκBα/NF-κB/TNF-α/IL-6 and CaMK-II/p-RIP3/p-MLKL/caspase-8,9 signaling pathways. In AP mice, a single dose of the formulation significantly restored pancreatic function (lipase and amylase reduced more by 60%) and improved the survival rate from 50 to 91.6%. The formulation offers a potentially effective strategy for clinical translation in AP treatment.


Asunto(s)
Pancreatitis , Tripsina , Animales , Pancreatitis/tratamiento farmacológico , Pancreatitis/patología , Pancreatitis/metabolismo , Tripsina/metabolismo , Tripsina/química , Ratones , Porosidad , Nanomedicina , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Nanopartículas/química , Dióxido de Silicio/química , Compuestos de Organosilicio/química , Compuestos de Organosilicio/farmacología , Masculino , Humanos , Células Acinares/efectos de los fármacos , Células Acinares/metabolismo , Células Acinares/patología , Ratones Endogámicos C57BL
4.
Metab Eng ; 85: 61-72, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39038602

RESUMEN

Advances in synthetic biology and artificial intelligence (AI) have provided new opportunities for modern biotechnology. High-performance cell factories, the backbone of industrial biotechnology, are ultimately responsible for determining whether a bio-based product succeeds or fails in the fierce competition with petroleum-based products. To date, one of the greatest challenges in synthetic biology is the creation of high-performance cell factories in a consistent and efficient manner. As so-called white-box models, numerous metabolic network models have been developed and used in computational strain design. Moreover, great progress has been made in AI-powered strain engineering in recent years. Both approaches have advantages and disadvantages. Therefore, the deep integration of AI with metabolic models is crucial for the construction of superior cell factories with higher titres, yields and production rates. The detailed applications of the latest advanced metabolic models and AI in computational strain design are summarized in this review. Additionally, approaches for the deep integration of AI and metabolic models are discussed. It is anticipated that advanced mechanistic metabolic models powered by AI will pave the way for the efficient construction of powerful industrial chassis strains in the coming years.

5.
Mol Ther ; 32(7): 2223-2231, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38796702

RESUMEN

Positron emission tomography (PET) reporter systems are a valuable means of estimating the level of expression of a transgene in vivo. For example, the safety and efficacy of gene therapy approaches for the treatment of neurological and neuropsychiatric disorders could be enhanced via the monitoring of exogenous gene expression levels in the brain. The present study evaluated the ability of a newly developed PET reporter system [18F]fluoroestradiol ([18F]FES) and the estrogen receptor-based PET reporter ChRERα, to monitor expression levels of a small hairpin RNA (shRNA) designed to suppress choline acetyltransferase (ChAT) expression in rhesus monkey brain. The ChRERα gene and shRNA were expressed from the same transcript via lentivirus injected into monkey striatum. In two monkeys that received injections of viral vector, [18F]FES binding increased by 70% and 86% at the target sites compared with pre-injection, demonstrating that ChRERα expression could be visualized in vivo with PET imaging. Post-mortem immunohistochemistry confirmed that ChAT expression was significantly suppressed in regions in which [18F]FES uptake was increased. The consistency between PET imaging and immunohistochemical results suggests that [18F]FES and ChRERα can serve as a PET reporter system in rhesus monkey brain for in vivo evaluation of the expression of potential therapeutic agents, such as shRNAs.


Asunto(s)
Encéfalo , Estradiol , Genes Reporteros , Macaca mulatta , Tomografía de Emisión de Positrones , Animales , Tomografía de Emisión de Positrones/métodos , Estradiol/análogos & derivados , Estradiol/farmacología , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagen , Radioisótopos de Flúor , Receptores de Estrógenos/metabolismo , Receptores de Estrógenos/genética , Vectores Genéticos/genética , Vectores Genéticos/administración & dosificación , Expresión Génica , ARN Interferente Pequeño/genética , Lentivirus/genética , Humanos
6.
Microb Pathog ; 192: 106685, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38750774

RESUMEN

QseC is a membrane sensor kinase that enables bacteria to perceive autoinducers -3, adrenaline, and norepinephrine to initiate downstream gene transcription. In this study, we found that the QseC protein of Glaesserella parasuis can serve as an effective antigen to activate the host's immune response. Therefore, we investigated the immunogenicity and host protective effect of this protein. ELISA and indirect immunofluorescence results showed that QseC protein can induce high titer levels of humoral immunity in mice and regularly generate specific serum antibodies. We used MTS reagents to detect lymphocyte proliferation levels and found that QseC protein can cause splenic lymphocyte proliferation with memory and specificity. Further immunological analysis of the spleen cell supernatant revealed significant upregulation of levels of IL-1ß, IL-4 and IFN-γ in the QseC + adjuvant group. In the mouse challenge experiment, it was found that QseC + adjuvant can provide effective protection. The results of this study demonstrate that QseC protein provides effective protection in a mouse model and has the potential to serve as a candidate antigen for a novel subunit vaccine for further research.


Asunto(s)
Anticuerpos Antibacterianos , Infecciones por Haemophilus , Interferón gamma , Interleucina-4 , Animales , Ratones , Interleucina-4/metabolismo , Interleucina-4/inmunología , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Infecciones por Haemophilus/inmunología , Infecciones por Haemophilus/prevención & control , Infecciones por Haemophilus/microbiología , Interferón gamma/metabolismo , Histidina Quinasa/genética , Histidina Quinasa/metabolismo , Histidina Quinasa/inmunología , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Inmunidad Humoral , Ratones Endogámicos BALB C , Bazo/inmunología , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/genética , Proliferación Celular , Femenino , Adyuvantes Inmunológicos , Haemophilus parasuis/inmunología , Haemophilus parasuis/genética , Citocinas/metabolismo , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/genética , Modelos Animales de Enfermedad , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/genética , Linfocitos/inmunología , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/genética
7.
ACS Nano ; 18(18): 11778-11803, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38652869

RESUMEN

Severe acute pancreatitis (AP) is a life-threatening pancreatic inflammatory disease with a high mortality rate (∼40%). Existing pharmaceutical therapies in development or in clinical trials showed insufficient treatment efficacy due to their single molecular therapeutic target, poor water solubility, short half-life, limited pancreas-targeting specificity, etc. Herein, acid-responsive hollow mesoporous Prussian blue nanoparticles wrapped with neutrophil membranes and surface modified with the N,N-dimethyl-1,3-propanediamine moiety were developed for codelivering membrane-permeable calcium chelator BAPTA-AM (BA) and trypsin activity inhibitor gabexate mesylate (Ga). In the AP mouse model, the formulation exhibited efficient recruitment at the inflammatory endothelium, trans-endothelial migration, and precise acinar cell targeting, resulting in rapid pancreatic localization and higher accumulation. A single low dose of the formulation (BA: 200 µg kg-1, Ga: 0.75 mg kg-1) significantly reduced pancreas function indicators to close to normal levels at 24 h, effectively restored the cell redox status, reduced apoptotic cell proportion, and blocked the systemic inflammatory amplified cascade, resulting in a dramatic increase in the survival rate from 58.3 to even 100%. Mechanistically, the formulation inhibited endoplasmic reticulum stress (IRE1/XBP1 and ATF4/CHOP axis) and restored impaired autophagy (Beclin-1/p62/LC3 axis), thereby preserving dying acinar cells and restoring the cellular "health status". This formulation provides an upstream therapeutic strategy with clinical translation prospects for AP management through synergistic ion homeostasis regulation and pancreatic autodigestion inhibition.


Asunto(s)
Células Acinares , Calcio , Homeostasis , Nanomedicina , Pancreatitis , Animales , Pancreatitis/tratamiento farmacológico , Pancreatitis/patología , Pancreatitis/metabolismo , Células Acinares/efectos de los fármacos , Células Acinares/metabolismo , Células Acinares/patología , Ratones , Homeostasis/efectos de los fármacos , Calcio/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/patología , Inflamación/metabolismo , Nanopartículas/química , Páncreas/patología , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Ratones Endogámicos C57BL , Masculino , Humanos
8.
IEEE Trans Image Process ; 33: 1361-1374, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38335088

RESUMEN

While the wisdom of training an image dehazing model on synthetic hazy data can alleviate the difficulty of collecting real-world hazy/clean image pairs, it brings the well-known domain shift problem. From a different yet new perspective, this paper explores contrastive learning with an adversarial training effort to leverage unpaired real-world hazy and clean images, thus alleviating the domain shift problem and enhancing the network's generalization ability in real-world scenarios. We propose an effective unsupervised contrastive learning paradigm for image dehazing, dubbed UCL-Dehaze. Unpaired real-world clean and hazy images are easily captured, and will serve as the important positive and negative samples respectively when training our UCL-Dehaze network. To train the network more effectively, we formulate a new self-contrastive perceptual loss function, which encourages the restored images to approach the positive samples and keep away from the negative samples in the embedding space. Besides the overall network architecture of UCL-Dehaze, adversarial training is utilized to align the distributions between the positive samples and the dehazed images. Compared with recent image dehazing works, UCL-Dehaze does not require paired data during training and utilizes unpaired positive/negative data to better enhance the dehazing performance. We conduct comprehensive experiments to evaluate our UCL-Dehaze and demonstrate its superiority over the state-of-the-arts, even only 1,800 unpaired real-world images are used to train our network. Source code is publicly available at https://github.com/yz-wang/UCL-Dehaze.

9.
Small ; 20(20): e2308585, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38212280

RESUMEN

This study addresses the challenge of designing simple and environmentally friendly methods for the preparation of effective electromagnetic wave (EMW) absorbing materials with tailored microstructures and multi-component regulation. N, O doped walnut-like porous carbon composite microspheres loaded with FeCo nanoparticles (WPCM/Fe-Co) are synthesized through high-temperature carbonization combined with soap-free emulsion polymerization and hydrothermal methods, avoiding the use of toxic solvents and complex conditions. The incorporation of magnetic components enhances magnetic loss, complementing dielectric loss to optimize EMW attenuation. The unique walnut-like morphology further improves impedance matching. The proportions of Fe and Co components can be adjusted to regulate the material's reflection loss, thickness, and bandwidth, allowing for fine-tuning of absorption performance. At a low filling ratio (16.7%), the optimal WPCM/Fe-Co composites exhibit a minimum reflection loss (RLmin) of -48.34 dB (10.33 GHz, 3.0 mm) and an overall effective absorbing bandwidth (EAB) covering the entire C bands, X bands, and Ku bands. This work introduces a novel approach to composition regulation and presents a green synthesis method for magnetic carbon composite absorbers with high-performance EMW absorption at low loading.

10.
Sci Rep ; 13(1): 21416, 2023 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-38049461

RESUMEN

To investigate the influence of different grasping postures on the hand's skin deformation, a handheld 3D EVA SCANNER was used to obtain 3D models of 111 women in five postures, including a straight posture and grasping cylinders with various diameters (4/6/8/10 cm). Skin relaxation strain ratio ([Formula: see text]) and surface area skin relaxation strain ratio ([Formula: see text]) were used as measures of skin deformation between two landmarks and multiple landmarks, respectively. The effects of grasping posture on skin deformation in different directions were analyzed. The results revealed significant variations in skin deformation among different grasping postures, except for the width of middle finger metacarpal and the length of middle finger's proximal phalanx. The [Formula: see text] increased with decreasing grasping object diameter, ranging from 5 to 18% on the coronal axis, and from 4 to 20% on the vertical axis. The overall variation of [Formula: see text] ranged from 5 to 37.5%, following the same trend as [Formula: see text] except for the surface area of tiger's mouth, which exhibited a maximum difference of 10.9% with significant differences. These findings have potential applications in improving the design of hand equipment and understanding hand movement characteristics.


Asunto(s)
Mano , Huesos del Metacarpo , Humanos , Femenino , Postura , Dedos , Movimiento , Fuerza de la Mano
11.
Artículo en Inglés | MEDLINE | ID: mdl-37948146

RESUMEN

There is a prevailing trend towards fusing multi-modal information for 3D object detection (3OD). However, challenges related to computational efficiency, plug-and-play capabilities, and accurate feature alignment have not been adequately addressed in the design of multi-modal fusion networks. In this paper, we present PointSee, a lightweight, flexible, and effective multi-modal fusion solution to facilitate various 3OD networks by semantic feature enhancement of point clouds (e.g., LiDAR or RGB-D data) assembled with scene images. Beyond the existing wisdom of 3OD, PointSee consists of a hidden module (HM) and a seen module (SM): HM decorates point clouds using 2D image information in an offline fusion manner, leading to minimal or even no adaptations of existing 3OD networks; SM further enriches the point clouds by acquiring point-wise representative semantic features, leading to enhanced performance of existing 3OD networks. Besides the new architecture of PointSee, we propose a simple yet efficient training strategy, to ease the potential inaccurate regressions of 2D object detection networks. Extensive experiments on the popular outdoor/indoor benchmarks show quantitative and qualitative improvements of our PointSee over thirty-five state-of-the-art methods.

12.
Bioprocess Biosyst Eng ; 46(11): 1677-1693, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37878184

RESUMEN

The quality prediction of batch processes is an important task in the field of biological fermentation. However, dynamic nonlinearity, unequal sampling intervals, uneven duration, and multiple features of a batch process make this task challenging. Thus, the multiple-feature fusion transformer (MFFT) model is proposed for the time series quality prediction of a batch process. First, the application of sequence-to-sequence architecture enables MFFT to perform a wide range of sequence prediction tasks. Second, the transformer parallel operation model imposes no rigid requirement for the order of sequence input, allowing the model to deal with problems of unequal interval sampling and utilize the sequence information. Third, MFFT integrates a pretrained ResNet50 as a mycelium status classifier for fusing image information into the features. Moreover, a multiple-feature encoding structure is proposed to integrate sampling time and mycelium status. Finally, multiple tasks in penicillin fermentation have shown that MFFT significantly outperforms existing methods for time series prediction.


Asunto(s)
Micelio , Penicilinas , Fermentación , Factores de Tiempo
13.
Polymers (Basel) ; 15(16)2023 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-37631451

RESUMEN

Through the effective combination of photothermal conversion agent polydopamine (PDA) nanoparticles and epoxy acrylate polymer (EA), a new kind of near-infrared (NIR) light-triggered shape memory polymer (PDA/EA) is developed. Due to the outstanding photothermal effect of PDA, even with a very low concentration of PDA (0.1 wt.%), when exposed to an 808 nm NIR light with a power of 1 W/cm2, the temporary shapes can be fully light-responsive, recovered in 60 s. Based on dynamic thermomechanical analysis and thermal gravimetric analysis, it can be seen that the introduction of PDA is beneficial for improving dynamic mechanical properties and thermal resistance compared to EA. As an environmentally friendly and highly efficient photoactive SMP, PDA/EA has a great application prospect.

15.
Curr Res Neurobiol ; 4: 100091, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37397810

RESUMEN

Genetically encoded synthetic receptors, such as the chemogenetic and optogenetic proteins, are powerful tools for functional brain studies in animals. In the primate brain, with its comparatively large, intricate anatomical structures, it can be challenging to express transgenes, such as the hM4Di chemogenetic receptor, in a defined anatomical structure with high penetrance. Here, we compare parameters for lentivirus vector injections in the rhesus monkey amygdala. We find that four injections of 20 µl, infused at 0.5 µl/min, can achieve neuronal hM4Di expression in 50-100% of neurons within a 60 mm3 volume, without observable damage from overexpression. Increasing the number of hM4Di_CFP lentivirus injections to up to 12 sites per hemisphere, resulted in 30%-40% neuronal coverage of the overall amygdala volume, with coverage reaching 60% in some subnuclei. Manganese Chloride was mixed with lentivirus and used as an MRI marker to verify targeting accuracy and correct unsuccessful injections in these experiments. In a separate monkey we visualized, in vivo, viral expression of the hM4Di receptor protein in the amygdala, using Positron Emission Tomography. Together, these data show efficient and verifiable expression of a chemogenetic receptor in old-world monkey amygdala.

16.
Biotechnol Bioeng ; 120(8): 2301-2313, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37448239

RESUMEN

Genome-scale metabolic network model (GSMM) based on enzyme constraints greatly improves general metabolic models. The turnover number ( k cat ${k}_{\mathrm{cat}}$ ) of enzymes is used as a parameter to limit the reaction when extending GSMM. Therefore, turnover number plays a crucial role in the prediction accuracy of cell metabolism. In this work, we proposed an enzyme-constrained GSMM parameter optimization method. First, sensitivity analysis of the parameters was carried out to select the parameters with the greatest influence on predicting the specific growth rate. Then, differential evolution (DE) algorithm with adaptive mutation strategy was adopted to optimize the parameters. This algorithm can dynamically select five different mutation strategies. Finally, the specific growth rate prediction, flux variability, and phase plane of the optimized model were analyzed to further evaluate the model. The enzyme-constrained GSMM of Saccharomyces cerevisiae, ecYeast8.3.4, was optimized. Results of the sensitivity analysis showed that the optimization variables can be divided into three groups based on sensitivity: most sensitive (149 k cat ${k}_{\mathrm{cat}}$ c), highly sensitive (1759 k cat ${k}_{\mathrm{cat}}$ ), and nonsensitive (2502 k cat ${k}_{\mathrm{cat}}$ ) groups. Six optimization strategies were developed based on the results of the sensitivity analysis. The results showed that the DE with adaptive mutation strategy can indeed improve the model by optimizing highly sensitive parameters. Retaining all parameters and optimizing the highly sensitive parameters are the recommended optimization strategy.


Asunto(s)
Algoritmos , Redes y Vías Metabólicas , Redes y Vías Metabólicas/genética , Mutación , Modelos Biológicos
17.
J Colloid Interface Sci ; 646: 54-66, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37182259

RESUMEN

Nowadays, multifunction is regarded as an advanced development direction of new-generation electromagnetic wave absorption (EMWA) materials to fulfill the ever-growing demands in complex environment and situation. Environmental pollution and electromagnetic pollution are all difficult problems for human beings all the time. Now, there is no multifunctional materials for collaborative treatment of environmental and electromagnetic pollution. Herein, We synthesized nanospheres with divinyl benzene (DVB) and N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA), using a simple one-pot method. After calcination at 800 ℃ in N2, porous N, O-doped porous carbon materials were prepared. By regulating the mole ratio of DVB and DMAPMA, the ratio was 5:1 reached excellent EMWA property. Remarkably, the introduction of iron acetylacetonate into the reaction of DVB and DMAPMA was effective in enhancing the absorption bandwidth to 8.00 GHz at a 3.74 mm thickness, which depended on the synergistic effects from dielectric and magnetic losses. Simultaneously, the Fe-doped carbon materials had a methyl orange adsorption capacity. The adsorption isotherm conformed to the Freundlich model. After methyl orange absorption, the EMWA property did not greatly change. Thus, this research paves the way for the creation of multifunctional materials to solve environmental pollution and electromagnetic pollution together.

18.
Eur J Nucl Med Mol Imaging ; 50(10): 2962-2970, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37249618

RESUMEN

PURPOSE: [18F]SF51 was previously found to have high binding affinity and selectivity for 18 kDa translocator protein (TSPO) in mouse brain. This study sought to assess the ability of [18F]SF51 to quantify TSPO in rhesus monkey brain. METHODS: Positron emission tomography (PET) imaging was performed in monkey brain (n = 3) at baseline and after pre-blockade with the TSPO ligands PK11195 and PBR28. TSPO binding was calculated as total distribution volume corrected for free parent fraction in plasma (VT/fP) using a two-tissue compartment model. Receptor occupancy and nondisplaceable uptake were determined via Lassen plot. Binding potential (BPND) was calculated as the ratio of specific binding to nondisplaceable uptake. Time stability of VT was used as an indirect probe to detect radiometabolite accumulation in the brain. In vivo and ex vivo experiments were performed in mice to determine the distribution of the radioligand. RESULTS: After [18F]SF51 injection, the concentration of brain radioactivity peaked at 2.0 standardized uptake value (SUV) at ~ 10 min and declined to 30% of the peak at 180 min. VT/fP at baseline was generally high (203 ± 15 mL· cm-3) and decreased by ~ 90% after blockade with PK11195. BPND of the whole brain was 7.6 ± 4.3. VT values reached levels similar to terminal 180-min values by 100 min and remained relatively stable thereafter with excellent identifiability (standard errors < 5%), suggesting that no significant radiometabolites accumulated in the brain. Ex vivo experiments in mouse brain showed that 96% of radioactivity was parent. No significant uptake was observed in the skull, suggesting a lack of defluorination in vivo. CONCLUSION: The results demonstrate that [18F]SF51 is an excellent radioligand that can quantify TSPO with a good ratio of specific to nondisplaceable uptake and has minimal radiometabolite accumulation in brain. Collectively, the results suggest that [18F]SF51 warrants further evaluation in humans.


Asunto(s)
Encéfalo , Receptores de GABA , Humanos , Ratones , Animales , Receptores de GABA/metabolismo , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Tomografía de Emisión de Positrones/métodos , Proteínas Portadoras/metabolismo , Unión Proteica , Radiofármacos/metabolismo
19.
IEEE Trans Pattern Anal Mach Intell ; 45(8): 9374-9392, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37022019

RESUMEN

Convolution on 3D point clouds is widely researched yet far from perfect in geometric deep learning. The traditional wisdom of convolution characterises feature correspondences indistinguishably among 3D points, arising an intrinsic limitation of poor distinctive feature learning. In this article, we propose Adaptive Graph Convolution (AGConv) for wide applications of point cloud analysis. AGConv generates adaptive kernels for points according to their dynamically learned features. Compared with the solution of using fixed/isotropic kernels, AGConv improves the flexibility of point cloud convolutions, effectively and precisely capturing the diverse relations between points from different semantic parts. Unlike the popular attentional weight schemes, AGConv implements the adaptiveness inside the convolution operation instead of simply assigning different weights to the neighboring points. Extensive evaluations clearly show that our method outperforms state-of-the-arts of point cloud classification and segmentation on various benchmark datasets. Meanwhile, AGConv can flexibly serve more point cloud analysis approaches to boost their performance. To validate its flexibility and effectiveness, we explore AGConv-based paradigms of completion, denoising, upsampling, registration and circle extraction, which are comparable or even superior to their competitors.


Asunto(s)
Algoritmos , Benchmarking
20.
ACS Pharmacol Transl Sci ; 6(4): 614-632, 2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37082755

RESUMEN

[11C]CPPC has been advocated as a radioligand for colony-stimulating factor 1 receptor (CSF1R) with the potential for imaging neuroinflammation in human subjects with positron emission tomography (PET). This study sought to prepare fluoro analogs of CPPC with higher affinity to provide the potential for labeling with longer-lived fluorine-18 (t 1/2 = 109.8 min) and for delivery of higher CSF1R-specific PET signal in vivo. Seven fluorine-containing analogs of CPPC were prepared and four were found to have high inhibitory potency (IC50 in low to sub-nM range) and selectivity at CSF1R comparable with CPPC itself. One of these, a 4-fluoromethyl analog (Psa374), was investigated more deeply by labeling with carbon-11 (t 1/2 = 20.4 min) for PET studies in mouse and monkey. [11C]Psa374 showed high peak uptake in monkey brain but not in mouse brain. Pharmacological challenges revealed no CSF1R-specific binding in either species at baseline. [11C]CPPC also failed to show specific binding at baseline. Moreover, both [11C]Psa374 and [11C]CPPC showed brain efflux transporter substrate behavior in both species in vivo, although Psa374 did not show liability toward human efflux transporters in vitro. Further development of [11C]Psa374 in non-human primate models of neuroinflammation with demonstration of CSF1R-specific binding would be required to warrant the fluorine-18 labeling of Psa374 with a view to possible application in human subjects.

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