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1.
Sci Rep ; 14(1): 8384, 2024 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600114

RESUMO

Spindle-shaped waves of oscillations emerge in EEG scalp recordings during human and rodent non-REM sleep. The association of these 10-16 Hz oscillations with events during prior wakefulness suggests a role in memory consolidation. Human and rodent depth electrodes in the brain record strong spindles throughout the cortex and hippocampus, with possible origins in the thalamus. However, the source and targets of the spindle oscillations from the hippocampus are unclear. Here, we employed an in vitro reconstruction of four subregions of the hippocampal formation with separate microfluidic tunnels for single axon communication between subregions assembled on top of a microelectrode array. We recorded spontaneous 400-1000 ms long spindle waves at 10-16 Hz in single axons passing between subregions as well as from individual neurons in those subregions. Spindles were nested within slow waves. The highest amplitudes and most frequent occurrence suggest origins in CA3 neurons that send feed-forward axons into CA1 and feedback axons into DG. Spindles had 50-70% slower conduction velocities than spikes and were not phase-locked to spikes suggesting that spindle mechanisms are independent of action potentials. Therefore, consolidation of declarative-cognitive memories in the hippocampus may be separate from the more easily accessible consolidation of memories related to thalamic motor function.


Assuntos
Hipocampo , Tálamo , Humanos , Hipocampo/fisiologia , Tálamo/fisiologia , Córtex Cerebral/fisiologia , Axônios , Neurônios , Eletroencefalografia , Sono/fisiologia
2.
Front Neural Circuits ; 17: 1272925, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38144878

RESUMO

The sub-regions of the hippocampal formation are essential for episodic learning and memory formation, yet the spike dynamics of each region contributing to this function are poorly understood, in part because of a lack of access to the inter-regional communicating axons. Here, we reconstructed hippocampal networks confined to four subcompartments in 2D cultures on a multi-electrode array that monitors individual communicating axons. In our novel device, somal, and axonal activity was measured simultaneously with the ability to ascertain the direction and speed of information transmission. Each sub-region and inter-regional axons had unique power-law spiking dynamics, indicating differences in computational functions, with abundant axonal feedback. After stimulation, spiking, and burst rates decreased in all sub-regions, spikes per burst generally decreased, intraburst spike rates increased, and burst duration decreased, which were specific for each sub-region. These changes in spiking dynamics post-stimulation were found to occupy a narrow range, consistent with the maintenance of the network at a critical state. Functional connections between the sub-region neurons and communicating axons in our device revealed homeostatic network routing strategies post-stimulation in which spontaneous feedback activity was selectively decreased and balanced by decreased feed-forward activity. Post-stimulation, the number of functional connections per array decreased, but the reliability of those connections increased. The networks maintained a balance in spiking and bursting dynamics in response to stimulation and sharpened network routing. These plastic characteristics of the network revealed the dynamic architecture of hippocampal computations in response to stimulation by selective routing on a spatiotemporal scale in single axons.


Assuntos
Axônios , Hipocampo , Reprodutibilidade dos Testes , Hipocampo/fisiologia , Axônios/fisiologia , Córtex Cerebral , Neurônios/fisiologia
4.
J Neural Eng ; 20(5)2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37666242

RESUMO

Objective. Decoding memory functions for each hippocampal subregion involves extensive understanding of how each hippocampal subnetwork processes input stimuli. Theta burst stimulation (TBS) recapitulates natural brain stimuli which potentiates synapses in hippocampal circuits. TBS is typically applied to a bundle of axons to measure the immediate response in a downstream subregion like the cornu ammonis 1 (CA1). Yet little is known about network processing in response to stimulation, especially because individual axonal transmission between subregions is not accessible.Approach. To address these limitations, we reverse engineered the hippocampal network on a micro-electrode array partitioned by a MEMS four-chambered device with interconnecting microfluidic tunnels. The micro tunnels allowed monitoring single axon transmission which is inaccessible in slices orin vivo. The four chambers were plated separately with entorhinal cortex (EC), dentate gyrus (DG), CA1, and CA3 neurons. The patterned TBS was delivered to the EC hippocampal gateway. Evoked spike pattern similarity in each subregions was quantified with Jaccard distance metrics of spike timing.Main results. We found that the network subregion produced unique axonal responses to different stimulation patterns. Single site and multisite stimulations caused distinct information routing of axonal spikes in the network. The most spatially similar output at axons from CA3 to CA1 reflected the auto association within CA3 recurrent networks. Moreover, the spike pattern similarities shifted from high levels for axons to and from DG at 0.2 s repeat stimuli to greater similarity in axons to and from CA1 for repetitions at 10 s intervals. This time-dependent response suggested that CA3 encoded temporal information and axons transmitted the information to CA1.Significance. Our design and interrogation approach provide first insights into differences in information transmission between the four subregions of the structured hippocampal network and the dynamic pattern variations in response to stimulation at the subregional level to achieve probabilistic pattern separation and novelty detection.


Assuntos
Córtex Entorrinal , Estimulação Magnética Transcraniana , Hipocampo , Região CA1 Hipocampal , Axônios
5.
Front Genet ; 14: 1192799, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37229187

RESUMO

Acute myeloid leukemia (AML) is a heterogeneous and deadly disease characterized by uncontrolled expansion of malignant blasts. Altered metabolism and dysregulated microRNA (miRNA) expression profiles are both characteristic of AML. However, there is a paucity of studies exploring how changes in the metabolic state of the leukemic cells regulate miRNA expression leading to altered cellular behavior. Here, we blocked pyruvate entry into mitochondria by deleting the Mitochondria Pyruvate Carrier (MPC1) gene in human AML cell lines, which decreased Oxidative Phosphorylation (OXPHOS). This metabolic shift also led to increased expression of miR-1 in the human AML cell lines tested. AML patient sample datasets showed that higher miR-1 expression correlates with reduced survival. Transcriptional and metabolic profiling of miR-1 overexpressing AML cells revealed that miR-1 increased OXPHOS, along with key metabolites that fuel the TCA cycle such as glutamine and fumaric acid. Inhibition of glutaminolysis decreased OXPHOS in miR-1 overexpressing MV4-11 cells, highlighting that miR-1 promotes OXPHOS through glutaminolysis. Finally, overexpression of miR-1 in AML cells exacerbated disease in a mouse xenograft model. Together, our work expands current knowledge within the field by uncovering novel connections between AML cell metabolism and miRNA expression that facilitates disease progression. Further, our work points to miR-1 as a potential new therapeutic target that may be used to disrupt AML cell metabolism and thus pathogenesis in the clinic.

6.
J Immunol ; 210(7): 926-934, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36883849

RESUMO

The proinflammatory microRNA-155 (miR-155) is highly expressed in the serum and CNS lesions of patients with multiple sclerosis (MS). Global knockout (KO) of miR-155 in mice confers resistance to a mouse model of MS, experimental autoimmune encephalomyelitis (EAE), by reducing the encephalogenic potential of CNS-infiltrating Th17 T cells. However, cell-intrinsic roles for miR-155 during EAE have not been formally determined. In this study, we use single-cell RNA sequencing and cell-specific conditional miR-155 KOs to determine the importance of miR-155 expression in distinct immune cell populations. Time-course single-cell sequencing revealed reductions in T cells, macrophages, and dendritic cells (DCs) in global miR-155 KO mice compared with wild-type controls at day 21 after EAE induction. Deletion of miR-155 in T cells, driven by CD4 Cre, significantly reduced disease severity similar to global miR-155 KOs. CD11c Cre-mediated deletion of miR-155 in DCs also resulted in a modest yet significant reduction in the development of EAE, with both T cell- and DC-specific KOs showing a reduction in Th17 T cell infiltration into the CNS. Although miR-155 is highly expressed in infiltrating macrophages during EAE, deletion of miR-155 using LysM Cre did not impact disease severity. Taken together, these data show that although miR-155 is highly expressed in most infiltrating immune cells, miR-155 has distinct roles and requirements depending on the cell type, and we have demonstrated this using the gold standard conditional KO approach. This provides insights into which functionally relevant cell types should be targeted by the next generation of miRNA therapeutics.


Assuntos
Encefalomielite Autoimune Experimental , MicroRNAs , Esclerose Múltipla , Animais , Camundongos , Doenças Neuroinflamatórias , Células Th17/metabolismo , Encéfalo/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout
7.
Cancers (Basel) ; 15(5)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36900204

RESUMO

(1) Background: Immune cells infiltrate the tumor microenvironment and secrete inflammatory cytokines, including interferons (IFNs), to drive antitumor responses and promote tumor clearance. However, recent evidence suggests that sometimes, tumor cells can also harness IFNs to enhance growth and survival. The essential NAD+ salvage pathway enzyme nicotinamide phosphoribosyltransferase (NAMPT) gene is constitutively expressed in cells during normal homeostasis. However, melanoma cells have higher energetic demands and elevated NAMPT expression. We hypothesized that interferon gamma (IFNγ) regulates NAMPT in tumor cells as a mechanism of resistance that impedes the normal anti-tumorigenic effects of IFNγ. (2) Methods: Utilizing a variety of melanoma cells, mouse models, Crispr-Cas9, and molecular biology techniques, we explored the importance of IFNγ-inducible NAMPT during melanoma growth. (3) Results: We demonstrated that IFNγ mediates the metabolic reprogramming of melanoma cells by inducing Nampt through a Stat1 binding site in the Nampt gene, increasing cell proliferation and survival. Further, IFN/STAT1-inducible Nampt promotes melanoma in vivo. (4) Conclusions: We provided evidence that melanoma cells directly respond to IFNγ by increasing NAMPT levels, improving their fitness and growth in vivo (control n = 36, SBS KO n = 46). This discovery unveils a possible therapeutic target that may improve the efficacy of immunotherapies involving IFN responses in the clinic.

8.
Cereb Cortex ; 33(4): 959-968, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35348637

RESUMO

OBJECTIVE: Previous studies have revealed that, compared with Parkinson's disease (PD) patients without freezing of gait (FoG), the ones with FoG showed greater prefrontal activation while doing lower-limb movements involving standing, walking and turning, which require both locomotor and balance control. However, the relation between FoG and pure locomotor control as well as its underlying mechanism remain unclear. METHODS: A total of 56 PD subjects were recruited and allocated to PD-FoG and PD-noFoG subgroups, and 34 age-matched heathy adults were included as heathy control (HC). Functional near-infrared spectroscopy was used to measure their prefrontal activation in a sitting lower-limb movement task, wherein subjects were asked to sit and tap their right toes as big and as fast as possible. RESULTS: Result of one-way ANOVA (Group: PD-FoG vs. PD-noFoG vs. HC) revealed greater activation in the right prefrontal cortex in the PD-FoG group than in the other 2 groups. Linear mixed-effects model showed consistent result. Furthermore, the right prefrontal activation positively correlated with the severity of FoG symptoms in PD-FoG patients. CONCLUSION: These findings suggested that PD patients with FoG require additional cognitive resources to compensate their damaged automaticity in locomotor control, which is more pronounced in severe FoG patients than milder ones.


Assuntos
Transtornos Neurológicos da Marcha , Doença de Parkinson , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Transtornos Neurológicos da Marcha/diagnóstico por imagem , Transtornos Neurológicos da Marcha/etiologia , Postura Sentada , Marcha/fisiologia , Dedos do Pé
9.
J Endovasc Ther ; : 15266028221134891, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36408609

RESUMO

BACKGROUND: Endovascular interventions in infrapopliteal occlusive artery disease are becoming more complex, and this frequently tests the standard method of treatment, plain old balloon angioplasty (POBA). The potential that serration angioplasty could produce a more acceptable tibial artery lumen was assessed in this study. AIM: The aim of this single-center subgroup analysis was to compare acute angiographic results after endovascular treatment using the Serranator serration balloon catheter in patients participating in the PRELUDE-BTK trial with POBA of the infrapopliteal arteries. A secondary objective was to assess post-treatment hemodynamic improvements. METHODS: Our center enrolled 15 subjects and treated 17 lesions within the multicenter prospective core laboratory-adjudicated PRELUDE-BTK study. A 25 lesions analyzed separately were treated with POBA and then compared with the Serranator subset. In both cohorts, lesions were treated with either plain angioplasty or Serranator as a stand-alone therapy; subsequent methods, such as drug elution technologies, were not used. Acute angiographic results were analyzed by the SynvaCor angiographic core laboratory. To assess volumetric flow rates, data were analyzed with a fluid flow simulation software and compared against Poiseuille's Law. RESULTS: Final residual stenosis was 17.2%±8.2% in the Serranator group versus 33.7%±15.7% in the POBA group. The mean lumen diameter (MLD) gain for the Serranator group and the POBA group was 1.64±0.41 mm and 1.33±0.63 mm, respectively. The average atmospheric balloon inflation pressure was 5 ATM in the Serranator group versus 9 ATM in the POBA group. Neither group required a bailout stent; however, it was notable that there were significantly more chronic total occlusions (CTOs) treated in the Serranator group at 41.2% versus 12% in the POBA group. Regarding the effectiveness in improving hemodynamic blood flow for non-CTO lesions, the calculated average ratio of post-treatment to pre-treatment flow rates in the Serranator group was 238% than that for the POBA group. For CTO cases where pre-treatment flow rate was zero, final residual stenosis was used as the parameter for comparison. The Serranator group showed a 62% improvement in final residual stenosis over POBA. CONCLUSION: Endovascular treatment of the infrapopliteal arteries by use of the Serranator serration balloon provides a novel and promising method of action compared with standard balloon angioplasty and, thus, may have a leading role in complex below-the-knee arterial lesions. CLINICAL IMPACT: The Serranator device might help to adequately address issues with conventional routine techniques for the treatment of complex lesions in infrapopliteal arteries in patients with advanced stages of PAD and critical limb ischemia. Integrating modern technologies such as the Serranator balloon catheter into clinical routine is mandatory in order to gain a more favorable outcome in these severely diseased patients and, particularly, to reduce mortality and morbidity.

10.
Front Immunol ; 13: 929677, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36248881

RESUMO

The rising toll of cancer globally necessitates ingenuity in early detection and therapy. In the last decade, the utilization of immune signatures and immune-based therapies has made significant progress in the clinic; however, clinical standards leave many current and future patients without options. Non-coding RNAs, specifically microRNAs, have been explored in pre-clinical contexts with tremendous success. MicroRNAs play indispensable roles in programming the interactions between immune and cancer cells, many of which are current or potential immunotherapy targets. MicroRNAs mechanistically control a network of target genes that can alter immune and cancer cell biology. These insights provide us with opportunities and tools that may complement and improve immunotherapies. In this review, we discuss immune and cancer cell-derived miRNAs that regulate cancer immunity and examine miRNAs as an integral part of cancer diagnosis, classification, and therapy.


Assuntos
MicroRNAs , Neoplasias , Humanos , Imunoterapia , Neoplasias/tratamento farmacológico , Neoplasias/terapia
11.
JCI Insight ; 7(19)2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-36214220

RESUMO

Intercellular communication is critical for homeostasis in mammalian systems, including the gastrointestinal (GI) tract. Exosomes are nanoscale lipid extracellular vesicles that mediate communication between many cell types. Notably, the roles of immune cell exosomes in regulating GI homeostasis and inflammation are largely uncharacterized. By generating mouse strains deficient in cell-specific exosome production, we demonstrate deletion of the small GTPase Rab27A in CD11c+ cells exacerbated murine colitis, which was reversible through administration of DC-derived exosomes. Profiling RNAs within colon exosomes revealed a distinct subset of miRNAs carried by colon- and DC-derived exosomes. Among antiinflammatory exosomal miRNAs, miR-146a was transferred from gut immune cells to myeloid and T cells through a Rab27-dependent mechanism, targeting Traf6, IRAK-1, and NLRP3 in macrophages. Further, we have identified a potentially novel mode of exosome-mediated DC and macrophage crosstalk that is capable of skewing gut macrophages toward an antiinflammatory phenotype. Assessing clinical samples, RAB27A, select miRNAs, and RNA-binding proteins that load exosomal miRNAs were dysregulated in ulcerative colitis patient samples, consistent with our preclinical mouse model findings. Together, our work reveals an exosome-mediated regulatory mechanism underlying gut inflammation and paves the way for potential use of miRNA-containing exosomes as a novel therapeutic for inflammatory bowel disease.


Assuntos
Antígenos CD11 , Colite , Exossomos , Inflamação , Células Mieloides , Animais , Antígenos CD11/genética , Antígenos CD11/imunologia , Colite/genética , Colite/imunologia , Exossomos/genética , Exossomos/imunologia , Inflamação/genética , Inflamação/imunologia , Doenças Inflamatórias Intestinais/imunologia , Intestinos/imunologia , Lipídeos , Mamíferos/genética , Mamíferos/imunologia , Camundongos , MicroRNAs/imunologia , Proteínas Monoméricas de Ligação ao GTP/imunologia , Células Mieloides/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Fator 6 Associado a Receptor de TNF/imunologia
12.
Zootaxa ; 5150(3): 428-442, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-36095653

RESUMO

Two beetles, Ceratophila (Vovidesa) chipjonesi, new species, and Pharaxonotha perezi, new species, (Coleoptera: Erotylidae: Pharaxonothinae) are described from the male cones of the New World cycad Ceratozamia santillanii Prez-Farr. Vovides (Cycadales: Zamiaceae). Morphological analysis and keys are provided for distinguishing these from related beetles inhabiting Ceratozamia in Mexico.


Assuntos
Besouros , Zamiaceae , Animais , Cycadopsida , Masculino , México
13.
Asia Pac J Ophthalmol (Phila) ; 11(4): 314-327, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36041146

RESUMO

Retinal degeneration (RD) is a significant cause of incurable blindness worldwide. Photoreceptors and retinal pigmented epithelium are irreversibly damaged in advanced RD. Functional replacement of photoreceptors and/or retinal pigmented epithelium cells is a promising approach to restoring vision. This paper reviews the current status and explores future prospects of the transplantation therapy provided by pluripotent stem cell-derived retinal organoids (ROs). This review summarizes the status of rodent RD disease models and discusses RO culture and analytical tools to evaluate RO quality and function. Finally, we review and discuss the studies in which RO-derived cells or sheets were transplanted. In conclusion, methods to derive ROs from pluripotent stem cells have significantly improved and become more efficient in recent years. Meanwhile, more novel technologies are applied to characterize and validate RO quality. However, opportunity remains to optimize tissue differentiation protocols and achieve better RO reproducibility. In order to screen high-quality ROs for downstream applications, approaches such as noninvasive and label-free imaging and electrophysiological functional testing are promising and worth further investigation. Lastly, transplanted RO-derived tissues have allowed improvements in visual function in several RD models, showing promises for clinical applications in the future.


Assuntos
Organoides , Degeneração Retiniana , Humanos , Espécies Reativas de Oxigênio , Reprodutibilidade dos Testes , Retina , Degeneração Retiniana/terapia
14.
Sensors (Basel) ; 22(14)2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35890819

RESUMO

The Internet of Things (IoT) has become critical to the implementation of Industry 4.0. The successful operation of smart manufacturing depends on the ability to connect everything together. In this research, we applied the TOC (Theory of Constraints) to develop a wireless Wi-Fi intelligent programmable IoT controller that can be connected to and easily control PLCs. By applying the TOC-focused thinking steps to break through their original limitations, the development process guides the user to use the powerful and simple flow language process control syntax to efficiently connect to PLCs and realize the full range of IoT applications. Finally, this research uses oil-water mixer equipment as the target of continuous improvement and verification. The verification results meet the requirements of the default function. The IoT controller developed in this research uses a marine boiler to illustrate the application. The successful development of flow control language by TOC in this research will enable academic research on PLC-derivative applications. The results of this research will help more SMEs to move into smart manufacturing and the new realm of Industry 4.0.

15.
Front Big Data ; 5: 787421, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35496379

RESUMO

In this community review report, we discuss applications and techniques for fast machine learning (ML) in science-the concept of integrating powerful ML methods into the real-time experimental data processing loop to accelerate scientific discovery. The material for the report builds on two workshops held by the Fast ML for Science community and covers three main areas: applications for fast ML across a number of scientific domains; techniques for training and implementing performant and resource-efficient ML algorithms; and computing architectures, platforms, and technologies for deploying these algorithms. We also present overlapping challenges across the multiple scientific domains where common solutions can be found. This community report is intended to give plenty of examples and inspiration for scientific discovery through integrated and accelerated ML solutions. This is followed by a high-level overview and organization of technical advances, including an abundance of pointers to source material, which can enable these breakthroughs.

16.
Environ Sci Pollut Res Int ; 29(29): 44162-44174, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35122652

RESUMO

This paper applies the modified undesirable dynamic data envelopment analysis (DEA) model by considering the role of forest carbon sinks to evaluate European countries' carbon dioxide (CO2) emissions and productivity efficiency. Taking population and energy consumption as input variables, gross domestic product (GDP) as the desirable input, CO2 as the undesirable output, and fixed assets as an inter-temporal carry-out input variable, our results suggest considering the fixed amount of the forest carbon sinks significantly affects efficiency rankings. The overall efficiency rankings for Ireland, Austria, Italy, Germany, Spain, and Belgium look to be overrated, while those of Finland, France, and Netherlands are apparently underrated. In terms of Total-Factor Efficiency analysis, countries with the best performance in efficiency ranking are Denmark, Luxembourg, Norway, Sweden, and the UK, thanks to their long-term effort at addressing the impact of forest carbon sinks and the effect of CO2 emissions on efficiency.


Assuntos
Dióxido de Carbono , Florestas , Dióxido de Carbono/análise , Sequestro de Carbono , Europa (Continente) , Produto Interno Bruto
17.
J Vitreoretin Dis ; 6(4): 316-319, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37007928

RESUMO

Purpose: To recognize the novel finding of a bacillary layer detachment (BALAD) secondary to endogenous fungal endophthalmitis. Methods: Chart review, literature review. Results: BALAD is a recently described condition in which the photoreceptor layer splits at the level of the inner segment myoid. We describe a case of BALAD associated with endogenous fungal endophthalmitis and subsequent development of choroidal neovascularization, although it is unclear if BALAD contributed to neovessel formation. Conclusions: BALAD is generally seen in the setting of inflammatory or infectious retinal diseases. This is the first report of BALAD secondary to endogenous fungal endophthalmitis.

18.
J Vitreoretin Dis ; 6(2): 167-170, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37008670

RESUMO

Purpose: This work reports on the management of a large subretinal gas bubble after pneumatic retinopexy. Methods: A case report is discussed. Results: We report a case of subretinal gas after pneumatic retinopexy for rhegmatogenous retinal detachment that was managed with a series of head-positioning maneuvers to allow the subretinal gas to migrate into the vitreous cavity through the retinal break. Despite the subretinal bubbles being larger than the retinal break, this approach eliminated the subretinal gas and averted surgical intervention. Conclusions: Subretinal gas after pneumatic retinopexy can be successfully managed by head-positioning maneuvers in some cases, even if the subretinal gas bubble is larger than the retinal break.

19.
J Biophotonics ; 15(5): e202100269, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34837329

RESUMO

Mueller matrix imaging polarimetry (MMIP) is a promising technique for the textural characterization of biological tissue structures. To reveal the influence of imaging magnification on the robustness of Mueller matrix parameters (MMPs), the spatial scale stability of MMPs was studied. We established a new MMIP detector and derived the mathematical model of the spatial scale stability of MMPs. The biological tissues with well-defined structural components were imaged under different magnifications. Then, we compared and analyzed the textural features of the MMPs in the resulting images. The experimental results match the predictions of the mathematical model in these aspects: (a) magnification exhibits a strong nonlinear effect on the textural contrasts of MMPs images; (b) higher magnification does not necessarily lead to superior contrast for textural characterization; and (c) for different biological tissues, MMPs contrasts can be optimized differently, with some showing superior results. This study provides a reference for the experimental design and operation of the MMIP technique and is helpful for improving the characterization ability of MMPs.


Assuntos
Diagnóstico por Imagem , Modelos Teóricos , Diagnóstico por Imagem/métodos , Metaloproteinases da Matriz , Análise Espectral
20.
Heliyon ; 8(12): e12571, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36636217

RESUMO

Traditional Chinese medicine (TCM) has been frequently used as skin lightning agents. However, the mechanism of action of their effect is unclear. The present study aims to evaluate anti-tyrosinase activity of 10 commonly used TCM on mushroom (ab), human (hs) and mouse melanoma B16F0 (mm) tyrosinase (TYR) respectively. The results showed that at 1.0 mg/mL, extracts from Rosa rugosa Thumb, Morus alba L. and Paeonia lactiflora Pall were active against both abTYR and hsTYR (>50% inhibition), extracts from Bletilla striata (Thunb.) Rchb. F., Centella asiatica (L.) Urb, Cynanchum atratum L., Rosa canina L., Rhus chinensis Mill. and Glycyrrhiza urolensis Fisch. Ex DC. inhibited either abTYR or hsTYR (>50%), while extract from Tribulus terrestris L. had no/minimal activity (<10% inhibition). When treated with melanoma B16F0 cells, M. alba also significantly reduced mmTYR activity (70% at 250 µg/mL) and melanin content (50% at 250 µg/mL). These findings demonstrated inhibitory effects of 9 TCM against TYR and hence support their application as skin lightning agents. Our results also showed discrepancies in TYR activity from different sources, suggesting a testing regime of combining abTYR, hsTYR and mmTYR when developing depigmentation agents for human application.

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