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1.
Magn Reson Med ; 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39219160

RESUMO

PURPOSE: To introduce quantitative rapid gradient-echo (QRAGE), a novel approach for the simultaneous mapping of multiple quantitative MRI parameters, including water content, T1, T2*, and magnetic susceptibility at ultrahigh field strength. METHODS: QRAGE leverages a newly developed multi-echo MPnRAGE sequence, facilitating the acquisition of 171 distinct contrast images across a range of inversion and TE points. To maintain a short acquisition time, we introduce MIRAGE2, a novel model-based reconstruction method that exploits prior knowledge of temporal signal evolution, represented as damped complex exponentials. MIRAGE2 minimizes local Block-Hankel and Casorati matrices. Parameter maps are derived from the reconstructed contrast images through postprocessing steps. We validate QRAGE through extensive simulations, phantom studies, and in vivo experiments, demonstrating its capability for high-precision imaging. RESULTS: In vivo brain measurements show the promising performance of QRAGE, with test-retest SDs and deviations from reference methods of < 0.8% for water content, < 17 ms for T1, and < 0.7 ms for T2*. QRAGE achieves whole-brain coverage at a 1-mm isotropic resolution in just 7 min and 15 s, comparable to the acquisition time of an MP2RAGE scan. In addition, QRAGE generates a contrast image akin to the UNI image produced by MP2RAGE. CONCLUSION: QRAGE is a new, successful approach for simultaneously mapping multiple MR parameters at ultrahigh field.

2.
Nanotechnology ; 35(26)2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38522098

RESUMO

In industrial and engineering fields including lamination, melt-spinning, continuous casting, and fiber spinning, the flow caused by a continually moving surface is significant. Therefore, the problem of ternary hybrid nanofluid flow over a moving surface is studied. This study explores the stability and statistical analyses of the magnetohydrodynamics (MHD) forced flow of the ternary hybrid nanofluid with melting heat transfer phenomena. The impacts of viscous dissipation, Joule heating, and thermal radiation are also included in the flow. Different fluids including ternary hybrid nanofluid, hybrid nanofluids, and nanofluids with base fluid ethylene glycol (EG) are examined and compared, where magnetite (Fe3O4) and silica (SiO2) are taken as the magnetic nanomaterials while silver (Ag) is chosen as the nonmagnetic nanomaterial. The skin friction coefficient and the local Nusselt number are estimated through regression analysis. By employing similarity transformations, the governing partial differential equations are converted into non-linear ordinary differential equations. Then, the least square method is applied to solve the equations analytically. Dual solutions are established in a particular range of moving parameterλ. Due to this, a stability test is implemented to find the stable solution by using the bvp4c function in MATLAB software. It is found that the first solution is the stable one while the second is unstable. The use of ternary hybrid nanomaterials improves the heat transport rate. The increasing values of the Eckert number enlarge the heat passage. The fluid velocity and temperature profiles for nonmagnetic nanomaterials are higher than that of magnetic nanomaterials. The uniqueness and originality of this study stems from the fact that, to the best of the authors' knowledge, it is the first to use this combination technique.

3.
Biotechnol Lett ; 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-39424749

RESUMO

Interleukin-37 is a cytokine with potent immunosuppressive properties that has been shown to have potential to treat autoimmune and chronic inflammatory diseases, as well as certain types of cancer. IL-37 is a 19 kDa protein which interacts with proteins in receptor-dependent and receptor-independent pathways. The expression of the IL-37 protein cloned into the pET-28a vector was optimized in Rosetta 2(DE3) after comparing its expression with Rosetta-gami 2(DE3) and Rosetta 2(DE3) pLysS, which was then used for the large-scale production of IL-37. IMAC purification of IL-37 yielded > 97% pure 0.9 mg/mL protein from auto-induced fermentation. The IC50 value of IL-37 was < 1 µM, which was similar to that of doxorubicin, and proliferation of > 80% of all cancer cells was inhibited by 100 µg/mL of IL-37 protein. IL-37 may be a promising theragnostic target for cancer due to its comparable IC50 value with that of doxorubicin.

4.
J Dairy Sci ; 107(7): 5132-5149, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38395401

RESUMO

As the stress-inducible isoform of the heat-shock protein 90 (HSP90), the HSP90AA1 gene encodes HSP90α and plays an important role in heat stress (HS) response. Therefore, this study aimed to investigate the role of the HSP90AA1 gene in cellular responses during HS and to identify functional SNPs associated with thermotolerance in Holstein cattle. For the in vitro validation experiment of acute HS, cells from the Madin-Darby bovine kidney cell line were exposed to 42°C for 1 h, and various parameters were assessed, including cell apoptosis, cell autophagy, and the cellular functions of HSP90α by using its inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG). Furthermore, the polymorphisms identified in the HSP90AA1 gene and their functions related to HS were validated in vitro. Acute HS exposure induced cell apoptosis, cell autophagy, and upregulated expression of the HSP90AA1 gene. Inhibition of HSP90α by 17-AAG treatment had a significant effect on the expression of the HSP90α protein and increased cell apoptosis. However, autophagy decreased in comparison to the control treatment when cells were exposed to 42°C for 1 h. Five SNPs identified in the HSP90AA1 gene were significantly associated with rectal temperature and respiration score in Holstein cows, in which the rs109256957 SNP is located in the 3' untranslated region (3' UTR). Furthermore, we demonstrated that the 3' UTR of HSP90AA1 is a direct target of bta-miR-1224 by cell transfection with exogenous microRNA (miRNA) mimic and inhibitor. The luciferase assays revealed that the SNP rs109256957 affects the regulation of bta-miR-1224 binding activity and alters the expression of the HSP90AA1 gene. Heat stress-induced HSP90AA1 expression maintains cell survival by inhibiting cell apoptosis and increasing cell autophagy. The rs109256957 located in the 3' UTR region is a functional variation and it affects the HSP90AA1 expression by altering its binding activity with bta-miR-1224, thereby associating with the physiological parameters of Holstein cows.


Assuntos
Bovinos , Proteínas de Choque Térmico HSP90 , Resposta ao Choque Térmico , Animais , Bovinos/genética , Bovinos/fisiologia , Feminino , Benzoquinonas/farmacologia , Proteínas de Choque Térmico HSP90/genética , Lactamas Macrocíclicas/farmacologia , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único
5.
Int J Mol Sci ; 25(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38791372

RESUMO

Mulberry is a rapidly growing plant that thrives in diverse climatic, topographical, and soil types, spanning temperature and temperate countries. Mulberry plants are valued as functional foods for their abundant chemical composition, serving as a significant reservoir of bioactive compounds like proteins, polysaccharides, phenolics, and flavonoids. Moreover, these compounds displayed potent antioxidant activity by scavenging free radicals, inhibiting reactive oxygen species generation, and restoring elevated nitric oxide production induced by LPS stimulation through the downregulation of inducible NO synthase expression. Active components like oxyresveratrol found in Morus demonstrated anti-inflammatory effects by inhibiting leukocyte migration through the MEK/ERK signaling pathway. Gallic and chlorogenic acids in mulberry leaves (ML) powder-modulated TNF, IL-6, and IRS1 proteins, improving various inflammatory conditions by immune system modulation. As we delve deeper into understanding its anti-inflammatory potential and how it works therapeutically, it is crucial to refine the extraction process to enhance the effectiveness of its bioactive elements. Recent advancements in extraction techniques, such as solid-liquid extraction, pressurized liquid extraction, superficial fluid extraction, microwave-assisted extraction, and ultrasonic-assisted extraction, are being explored. Among the extraction methods tested, including Soxhlet extraction, maceration, and ultrasound-assisted extraction (UAE), UAE demonstrated superior efficiency in extracting bioactive compounds from mulberry leaves. Overall, this comprehensive review sheds light on the potential of mulberry as a natural immunomodulatory agent and provides insights into its mechanisms of action for future research and therapeutic applications.


Assuntos
Morus , Extratos Vegetais , Morus/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Humanos , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Agentes de Imunomodulação/farmacologia , Agentes de Imunomodulação/química , Fatores Imunológicos/farmacologia , Fatores Imunológicos/química , Folhas de Planta/química
6.
Molecules ; 29(20)2024 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-39459211

RESUMO

A balanced inflammatory response is crucial for the organism to defend against external infections, however, an exaggerated response may lead to detrimental effects, including tissue damage and even the onset of disease. Therefore, anti-inflammatory drugs are essential for the rational control of inflammation. In this study, we found that a previously screened peptide TaY (KEKKEVVEYGPSSYGYG) was able to inhibit the LPS-induced RAW264.7 inflammatory response by decreasing a series of proinflammatory cytokines, such as TNF-α, IL-6, and nitric oxide (NO). To elucidate the underlying mechanism, we conducted further investigations. Western blot analysis showed that TaY reduced the phosphorylation of key proteins (IKK-α/ß, IκB-α,NF-κB (P65)) in the TLR4-NF-κB signaling pathway and inhibited the inflammatory response. Furthermore, molecular docking and molecular dynamic simulations suggested that TaY binds to the hydrophobic pocket of MD2 through hydrogen bonding and hydrophobic interactions, potentially competing with LPS for MD2 binding. Collectively, TaY is a promising candidate for the development of novel therapeutic strategies against inflammatory disorders.


Assuntos
Inflamação , Lipopolissacarídeos , Antígeno 96 de Linfócito , Simulação de Acoplamento Molecular , NF-kappa B , Transdução de Sinais , Camundongos , Animais , Transdução de Sinais/efeitos dos fármacos , NF-kappa B/metabolismo , Células RAW 264.7 , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Antígeno 96 de Linfócito/metabolismo , Antígeno 96 de Linfócito/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Peptídeos/química , Peptídeos/farmacologia , Simulação de Dinâmica Molecular , Citocinas/metabolismo , Receptor 4 Toll-Like/metabolismo , Ligação Proteica , Óxido Nítrico/metabolismo
7.
Prep Biochem Biotechnol ; : 1-13, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38824503

RESUMO

Interleukin-2 has emerged as a potent protein-based drug to treat various cancers, AIDS, and autoimmune diseases. Despite its immense requirement, the production procedures are inefficient to meet the demand. Therefore, efficient production procedures must be adopted to improve protein yield and decrease procedural loss. This study analyzed cytoplasmic and periplasmic IL-2 expression for increased protein yield and significant biological activity. The study is focused on cloning IL-2 into a pET-SUMO and pET-28a vector that expresses IL-2 in soluble form and inclusion bodies, respectively. Both constructs were expressed into different E. coli expression strains, but the periplasmic and cytoplasmic expression of IL-2 was highest in overnight culture in Rosetta 2 (DE3). Therefore, E. coli Rosetta 2 (DE3) was selected for large-scale production and purification. Purified IL-2 was characterized by SDS-PAGE and western blotting, while its biological activity was determined using MTT bioassay. The results depict that the periplasmic and cytoplasmic IL-2 achieved adequate purification, yielding 0.86 and 0.51 mg/mL, respectively, with significant cytotoxic activity of periplasmic and cytoplasmic IL-2. Periplasmic IL-2 has shown better yield and significant biological activity in vitro which describes its attainment of native protein structure and function.

8.
J Magn Reson Imaging ; 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37855368

RESUMO

BACKGROUND: Given that changes in brain water content are often correlated with disease, investigating water content non-invasively and in vivo could lead to a better understanding of the pathogenesis of several neurologic diseases. PURPOSE: To adapt a super-resolution-based technique, previously developed for humans, to the rat brain and report in vivo high-resolution (HR) water content maps in comparison with ex vivo wet/dry methods. STUDY TYPE: Prospective. ANIMAL MODEL: Eight healthy male Wistar rats. FIELD STRENGTH/SEQUENCE: 9.4-T, multi-echo gradient-echo (mGRE) sequence. ASSESSMENT: Using super-resolution reconstruction (SRR), a HR mGRE image (200 µm isotropic) was reconstructed from three low-resolution (LR) orthogonal whole-brain images in each animal, which was followed by water content mapping in vivo. The animals were subsequently sacrificed, the brains excised and divided into five regions (front left, front right, middle left, middle right, and cerebellum-brainstem regions), and the water content was measured ex vivo using wet/dry measurements as the reference standard. The water content values of the in vivo and ex vivo methods were then compared for the whole brain and also for the different regions separately. STATISTICAL TESTS: Friedman's non-parametric test was used to test difference between the five regions, and Pearson's correlation coefficient was used for correlation between in vivo and ex vivo measurements. A P-value <0.05 was considered statistically significant. RESULTS: Water content values derived from in vivo MR measurements showed strong correlations with water content measured ex vivo at a regional level (r = 0.902). Different brain regions showed significantly different water content values. Water content values were highest in the frontal brain, followed by the midbrain, and lowest in the cerebellum and brainstem regions. DATA CONCLUSION: An in vivo technique to achieve HR isotropic water content maps in the rat brain using SRR was adopted in this study. The MRI-derived water content values obtained using the technique showed strong correlations with water content values obtained using ex vivo wet/dry methods. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 1.

9.
Adapt Behav ; 31(1): 3-19, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36618906

RESUMO

We present three new diagnostic prediction problems inspired by classical-conditioning experiments to facilitate research in online prediction learning. Experiments in classical conditioning show that animals such as rabbits, pigeons, and dogs can make long temporal associations that enable multi-step prediction. To replicate this remarkable ability, an agent must construct an internal state representation that summarizes its interaction history. Recurrent neural networks can automatically construct state and learn temporal associations. However, the current training methods are prohibitively expensive for online prediction-continual learning on every time step-which is the focus of this paper. Our proposed problems test the learning capabilities that animals readily exhibit and highlight the limitations of the current recurrent learning methods. While the proposed problems are nontrivial, they are still amenable to extensive testing and analysis in the small-compute regime, thereby enabling researchers to study issues in isolation, ultimately accelerating progress towards scalable online representation learning methods.

10.
Neuroimage ; 252: 119014, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35202813

RESUMO

The measurement of quantitative, tissue-specific MR properties, e.g., water content, longitudinal relaxation time (T1) and effective transverse relaxation time (T2⁎), using quantitative MRI at a clinical field strength (1.5 T to 3T) is a well-explored topic. However, none of the commonly used standard brain atlases, such as MNI or JHU, provide quantitative information. Within the framework of quantitative MRI of the brain, this work reports on the development of the first quantitative brain atlas for tissue water content at 3T. A methodology to create this quantitative atlas of in vivo brain water content based on healthy volunteers is presented, and preliminary, practical examples of its potential applications are also shown. Established methods for the fast and reliable measurement of the absolute water content were used to achieve high precision and accuracy. Water content and T2⁎ were mapped based on two different methods: an intermediate-TR, two-point method and a long-TR, single-scan method. Twenty healthy subjects (age 25.3 ± 2.5 years) were examined with these quantitative imaging protocols. The images were normalised to MNI stereotactic coordinates, and water content atlases of healthy volunteers were created for each method and compared. Regions-of-interest were generated with the help of a standard MNI template, and water content values averaged across the ROIs were compared to water content values from the literature. Finally, in order to demonstrate the strength of quantitative MRI, water content maps from patients with pathological changes in the brain due to stroke, tumour (glioblastoma) and multiple sclerosis were voxel-wise compared to the healthy brain. The water content atlases were largely independent of the method used to acquire the individual water maps. Global grey matter and white matter water content values between the methods agreed with each other to within 0.5 %. The feasibility of detecting abnormal water content in the brains of patients based on comparison to a healthy brain water content atlas was demonstrated. In summary, the first quantitative water content brain atlas in vivo has been developed, and a voxel-wise assessment of pathology-related changes in the brain water content has been performed. These results suggest that qMRI, in combination with a water content atlas, allows for a quantitative interpretation of changes due to disease and could be used for disease monitoring.


Assuntos
Água , Substância Branca , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Adulto Jovem
11.
Mol Biol Rep ; 49(12): 12039-12053, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36309612

RESUMO

BACKGROUNDS: The BRASSINAZOLE-RESISTANT (BZR) family of transcription factors affects a variety of developmental and physiological processes and plays a key role in multiple stress-resistance functions in plants. However, the evolutionary relationship and individual expression patterns of the BZR genes are unknown in various crop plants. METHODS AND RESULTS: In this study, we performed a genome-wide analysis of the BZR genes family in wheat and rice. Here, we found a total of 16 and 6 proteins containing the BZR domain in wheat and rice respectively. The phylogenetic analysis divided the identified BZR proteins from several plants into five subfamilies. The intron/exon structural patterns and conserved motifs distribution revealed that BZR proteins exhibite high specificities in each subfamily. Moreover, the co-expression and protein-protein interaction analysis suggested that BZR proteins may interact/co-expressed with several other proteins to perform various functions in plants. The presence of different stresses, hormones and light-responsive cis-elements in promoter regions of BZR genes imply its diverse functions in plants. The expression patterns indicated that many BZR genes regulate organ development and differentiation. BZR genes significantly respond to exogenous application of brassinosteroids, melatonin and abiotic stresses, demonstrating its key role in various developmental and physiological processes. CONCLUSION: The present study establishes the foundation for future functional genomics studies of BZR genes through reverse genetics and to further explore the potential of BZR genes in mitigating the stress tolerance in crop plants.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta , Filogenia , Triticum/metabolismo , Estresse Fisiológico/genética , Oryza/genética , Proteínas de Plantas/metabolismo , Família Multigênica
12.
Chem Biodivers ; 19(11): e202200521, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36149393

RESUMO

Convolvulus arvensis L. is an evergreen herb growing in various regions of Pakistan. Despite of several medicinal properties associated to this herb, it was not investigated scientifically for its bioactive compounds and detailed pharmaceutical properties. Therefore, its methanolic extract was divided into hexane (CA-H), chloroform (CA-C), ethyl acetate (CA-E) and butanol (CA-B) soluble fractions. CA-H and CA-C were found rich in phenolics (30.73±0.63 and 20.15±0.59 mg GAE/g of the extract, respectively), and the same fractions exhibited significant antioxidant activities (DPPH: 5.23±0.11 & 12.34±0.17 mg TE/g extract, respectively; ABTS: 36.82±0.04 & 56.74±0.61 mg TE/g extract, respectively). Also in CUPRAC activity assay, CA-H and CA-C exhibited highest activities as 87.30±0.46 and 56.74±0.61 mg TE/g extract, respectively, while CA-C was most active in FRAP activity assay with value of 40.21±2.19 mg TE/g extract. Total antioxidant capacity (1.23±0.033 mmol TE/g extract) was also found higher for CA-C, while CA-H activity was also comparable, however, CA-H showed higher metal chelating activity (22.74±0.001 mg EDTAE/g extract) than that of CA-C (17.55±0.22 mg EDTAE/g extract). These activities clearly revealed a direct relation between antioxidant potential and phenolic contents of CA-H and CA-C. In AChE and BChE inhibitory assay, CA-H and CA-E showed better inhibition (AChE: 8.24±0.77 & 4.46±0.007 mg GALAE/g extract; BChE: 5.40±0.02 & 1.92±0.24 mg GALAE/g extract) as compared to other fractions, whereas, against tyrosinase, CA-B was most active (37.35±0.53 mg KAE/g extract). CA-H and CA-C also showed higher inhibitory potential (0.98±0.08 & 0.58±0.01 mmol ACAE/g extract) against α-Amylase; while against α-Glucosidase, CA-E was the most active fraction. UHPLC/MS analysis of the methanolic extract of C. arvensis disclosed the presence of 62 compounds as sterols, triterpenes, flavonoids, fatty acids, alkaloids and coumarins. In Multivariate Analysis, the total phenolic contents were correlated strongly with all antioxidant assays except FRAP and DPPH. Regarding enzyme inhibitory properties, only AChE, BChE and α-amylase were correlated with the total phenolic contents in the extracts. Docking analyses confirmed these findings, as identified compounds had high binding free energy and inhibition constants with the enzymes studied. It was finally concluded that C. arvensis is a potential industrial crop, which can be a component of nutraceuticals and functional foods, if evaluated for its toxicity.


Assuntos
Antioxidantes , Convolvulus , Antioxidantes/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão , alfa-Amilases , Fenóis/química , Metanol/química , Análise Multivariada , Indústria Farmacêutica , Recursos Naturais , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/análise
13.
Int J Mol Sci ; 23(4)2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35216260

RESUMO

Heat stress affects granulosa cells and the ovarian follicular microenvironment, ultimately resulting in poor oocyte developmental competence. This study aims to investigate the metabo-lomics response of bovine granulosa cells (bGCs) to in vitro acute heat stress of 43 °C. Heat stress triggers oxidative stress-mediated apoptosis in cultured bGCs. Heat-stressed bGCs exhibited a time-dependent recovery of proliferation potential by 48 h. A total of 119 metabolites were identified through LC-MS/MS-based metabolomics of the spent culture media, out of which, 37 metabolites were determined as differentially involved in metabolic pathways related to bioenergetics support mechanisms and the physical adaptations of bGCs. Multiple analyses of metabolome data identified choline, citric acid, 3-hydroxy-3-methylglutaric acid, glutamine, and glycocyamine as being upregulated, while galactosamine, AICAR, ciliatine, 16-hydroxyhexadecanoic acid, lysine, succinic acid, uridine, xanthine, and uraconic acid were the important downregulated metabolites in acute heat stress. These differential metabolites were implicated in various important metabolic pathways directed towards bioenergetics support mechanisms including glycerophospholipid metabolism, the citrate cycle (TCA cycle), glyoxylate and dicarboxylate metabolism, and serine, threonine, and tyrosine metabolism. Our study presents important metabolites and metabolic pathways involved in the adaptation of bGCs to acute heat stress in vitro.


Assuntos
Células da Granulosa/metabolismo , Resposta ao Choque Térmico/fisiologia , Metaboloma/fisiologia , Animais , Apoptose/fisiologia , Bovinos , Doenças dos Bovinos/metabolismo , Células Cultivadas , Cromatografia Líquida/métodos , Feminino , Temperatura Alta , Metabolômica/métodos , Estresse Oxidativo/fisiologia , Espectrometria de Massas em Tandem/métodos
14.
Int J Mol Sci ; 23(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35163165

RESUMO

Recently, the drawbacks arising from the overuse of antibiotics have drawn growing public attention. Among them, drug-resistance (DR) and even multidrug-resistance (MDR) pose significant challenges in clinical practice. As a representative of a DR or MDR pathogen, Staphylococcus aureus can cause diversity of infections related to different organs, and can survive or adapt to the diverse hostile environments by switching into other phenotypes, including biofilm and small colony variants (SCVs), with altered physiologic or metabolic characteristics. In this review, we briefly describe the development of the DR/MDR as well as the classical mechanisms (accumulation of the resistant genes). Moreover, we use multidimensional scaling analysis to evaluate the MDR relevant hotspots in the recent published reports. Furthermore, we mainly focus on the possible non-classical resistance mechanisms triggered by the two important alternative phenotypes of the S. aureus, biofilm and SCVs, which are fundamentally caused by the different global regulation of the S. aureus population, such as the main quorum-sensing (QS) and agr system and its coordinated regulated factors, such as the SarA family proteins and the alternative sigma factor σB (SigB). Both the biofilm and the SCVs are able to escape from the host immune response, and resist the therapeutic effects of antibiotics through the physical or the biological barriers, and become less sensitive to some antibiotics by the dormant state with the limited metabolisms.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Animais , Proteínas de Bactérias/genética , Biofilmes/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica , Humanos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade
15.
Neuroimage ; 244: 118605, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34592438

RESUMO

BACKGROUND AND PURPOSE: The excess fluid as a result of vasogenic oedema and the subsequent tissue cavitation obscure the microstructural characterisation of ischaemic tissue by conventional diffusion and relaxometry MRI. They lead to a pseudo-normalisation of the water diffusivity and transverse relaxation time maps in the subacute and chronic phases of stroke. Within the context of diffusion MRI, the free water elimination and mapping method (FWE) with echo time dependence has been proposed as a promising approach to measure the amount of free fluid in brain tissue robustly and to eliminate its biasing effect on other biomarkers. In this longitudinal study of transient middle cerebral artery occlusion (MCAo) in the rat brain, we investigated the use of FWE MRI with echo time dependence for the characterisation of the tissue microstructure and explored the potential of the free water fraction as a novel biomarker of ischaemic tissue condition. METHODS: Adult rats received a transient MCAo. Diffusion- and transverse relaxation-weighted MRI experiments were performed longitudinally, pre-occlusion and on days 1, 3, 4, 5, 6, 7 and 10 after MCAo on four rats. Histology was performed for non-stroke and 1, 3 and 10 days after MCAo on three different rats at each time point. RESULTS: The free water fraction was homogeneously increased in the ischaemic cortex one day after stroke. Between three and ten days after stroke, the core of the ischaemic tissue showed a progressive normalisation in the amount of free water, whereas the inner and outer border zones of the ischaemic cortex depicted a large, monotonous increase with time. The specific lesions in brain sections were verified by H&E and immunostaining. The tissue-specific diffusion and relaxometry MRI metrics in the ischaemic cortex were significantly different compared to their conventional counterpart. CONCLUSIONS: Our results demonstrate that the free water fraction in FWE MRI with echo time dependence is a valuable biomarker, sensitive to the progressive degeneration in ischaemic tissue. We showed that part of the heterogeneity previously observed in conventional parameter maps can be accounted for by a heterogeneous distribution of free water in the tissue. Our results suggest that the temporal evolution of the free fluid fraction map at the core and inner border zone can be associated with the pathological changes linked to the evolution of vasogenic oedema. Namely, the homogeneous increase in free water one day after stroke and its tendency to normalise in the core of the ischaemic cortex starting three days after stroke, followed by a progressive increase in free water at the inner border zone from three to ten days after stroke. Finally, the monotonous increase in free fluid in the outer border zone of the cortex reflects the formation of fluid-filled cysts.


Assuntos
Água Corporal/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Animais , Córtex Cerebral/diagnóstico por imagem , Técnicas Histológicas , Estudos Longitudinais , Modelos Animais , Ratos
16.
Mol Biol Rep ; 48(9): 6581-6588, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34432219

RESUMO

Helminths are the old dirty friends of humans from decades and may live undetected by the immune system for years in the tissues. They have evolved as good experts at subverting the immune system. Despite of their pathogenicity, they provide protection to their host against certain inflammatory diseases such as diabetes by modulating the immune mechanisms. These parasites are extra-cellular and induce Th2 response which triggers the adaptive immune cells as well as innate immune cells to work synergistically allowing Tregs to work in a toll-like receptor-dependent manure. T-helper cells type-2 also secrete certain anti-inflammatory cytokines including IL-4, IL-10, IL-13 and TGF-ß which also provide protection against type-1 diabetes. Several helminths such as T. crassiceps, S. venezuelensis, filarial worms, Schistosoma spp. and T. spiralis have been reported to prevent diabetes in mouse models as well as in some clinical trials. Immunomodulatory talent of helminths is receiving greater attention to prevent diabetes. Herein, an attempt has been made to review and highlight the possible immuno-modulatory mechanisms by which helminths provide protection against diabetes. Moreover, this review also emphasizes on the use of helminth-derived molecules or synthetic derivatives of helminth-antigens in clinical trials to overcome rapidly growing autoimmune disorders including diabetes.


Assuntos
Imunidade Adaptativa , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Helmintíase/imunologia , Helmintos/imunologia , Imunidade Inata , Animais , Antígenos de Helmintos/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Helmintíase/parasitologia , Humanos , Camundongos , Linfócitos T Reguladores/imunologia , Células Th2/imunologia
17.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204328

RESUMO

The use of experimental relations to approximate the efficient thermophysical properties of a nanofluid (NF) with Cu nanoparticles (NPs) and hybrid nanofluid (HNF) with Cu-SWCNT NPs and subsequently model the two-dimensional pulsatile Casson fluid flow under the impact of the magnetic field and thermal radiation is a novelty of the current study. Heat and mass transfer analysis of the pulsatile flow of non-Newtonian Casson HNF via a Darcy-Forchheimer porous channel with compliant walls is presented. Such a problem offers a prospective model to study the blood flow via stenosed arteries. A finite-difference flow solver is used to numerically solve the system obtained using the vorticity stream function formulation on the time-dependent governing equations. The behavior of Cu-based NF and Cu-SWCNT-based HNF on the wall shear stress (WSS), velocity, temperature, and concentration profiles are analyzed graphically. The influence of the Casson parameter, radiation parameter, Hartmann number, Darcy number, Soret number, Reynolds number, Strouhal number, and Peclet number on the flow profiles are analyzed. Furthermore, the influence of the flow parameters on the non-dimensional numbers such as the skin friction coefficient, Nusselt number, and Sherwood number is also discussed. These quantities escalate as the Reynolds number is enhanced and reduce by escalating the porosity parameter. The Peclet number shows a high impact on the microorganism's density in a blood NF. The HNF has been shown to have superior thermal properties to the traditional one. These results could help in devising hydraulic treatments for blood flow in highly stenosed arteries, biomechanical system design, and industrial plants in which flow pulsation is essential.


Assuntos
Cobre , Hemodinâmica , Hidrodinâmica , Nanopartículas Metálicas , Modelos Cardiovasculares , Fluxo Pulsátil , Algoritmos , Artérias/patologia , Artérias/fisiopatologia , Circulação Sanguínea , Constrição Patológica , Cobre/química , Humanos , Nanopartículas Metálicas/química , Porosidade , Suspensões
18.
Int J Mol Sci ; 22(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34769113

RESUMO

The increasing numbers of infections caused by multidrug-resistant (MDR) pathogens highlight the urgent need for new alternatives to conventional antibiotics. Antimicrobial peptides have the potential to be promising alternatives to antibiotics because of their effective bactericidal activity and highly selective toxicity. The present study was conducted to investigate the antibacterial, antibiofilm, and anti-adhesion activities of different CTP peptides (CTP: the original hybrid peptide cathelicidin 2 (1-13)-thymopentin (TP5); CTP-NH2: C-terminal amidated derivative of cathelicidin 2 (1-13)-TP5; CTPQ: glutamine added at the C-terminus of cathelicidin 2 (1-13)-TP5) by determining the minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), propidium iodide uptake, and analysis by scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy). The results showed that CTPs had broad-spectrum antibacterial activity against different gram-positive and gram-negative bacteria, with MICs against the tested strains varying from 2 to 64 µg/mL. CTPs at the MBC (2 × MIC 64 µg/mL) showed strong bactericidal effects on a standard methicillin-resistant Staphylococcus aureus strain ATCC 43300 after co-incubation for 6 h through disruption of the bacterial membrane. In addition, CTPs at 2 × MIC also displayed effective inhibition activity of several S. aureus strains with a 40-90% decrease in biofilm formation by killing the bacteria embedded in the biofilms. CTPs had low cytotoxicity on the intestinal porcine epithelial cell line (IPEC-J2) and could significantly decrease the rate of adhesion of S. aureus ATCC 43300 on IPEC-J2 cells. The current study proved that CTPs have effective antibacterial, antibiofilm, and anti-adhesion activities. Overall, this study contributes to our understanding of the possible antibacterial and antibiofilm mechanisms of CTPs, which might be an effective anti-MDR drug candidate.


Assuntos
Catelicidinas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Timopentina , Biofilmes/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Testes de Sensibilidade Microbiana
19.
Metab Brain Dis ; 34(4): 1071-1076, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31089866

RESUMO

Hepatic encephalopathy (HE) is a frequent and debilitating complication of cirrhosis and its pathogenesis is not definitively clarified. Recent hypotheses focus on the possible existence of low-grade cerebral edema due to accumulation of osmolytes secondary to hyperammonemia. In the present study we investigated increases in cerebral water content by a novel magnetic resonance impedance (MRI) technique in cirrhosis patients with and without clinically manifest HE. We used a 3 T MRI technique for quantitative cerebral water content mapping in nine cirrhosis patients with an episode of overt HE, ten cirrhosis patients who never suffered from HE, and ten healthy aged-matched controls. We tested for differences between groups by statistical non-parametric mapping (SnPM) for a voxel-based spatial evaluation. The patients with HE had significantly higher water content in white matter than the cirrhosis patients (0.6%), who in turn, had significantly higher content than the controls (1.7%). Although the global gray matter water content did not differ between the groups, the patients with HE had markedly higher thalamic water content than patients who never experienced HE (6.0% higher). We found increased white matter water content in cirrhosis patients, predominantly in those with manifest HE. This confirms the presence of increasing degrees of low-grade edema with exacerbation of pathology. The thalamic edema in manifest HE may lead to compromised basal ganglia-thalamo-cortical circuits, in accordance with the major clinical symptoms of HE. The identification of the thalamus as particularly inflicted in manifest HE is potentially relevant to the pathophysiology of HE.


Assuntos
Edema Encefálico/patologia , Encéfalo/patologia , Encefalopatia Hepática/patologia , Cirrose Hepática/patologia , Água , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Edema Encefálico/diagnóstico por imagem , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Encefalopatia Hepática/diagnóstico por imagem , Humanos , Cirrose Hepática/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto Jovem
20.
Sensors (Basel) ; 20(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881686

RESUMO

Procalcitonin (PCT) protein has recently been identified as a clinical marker for bacterial infections based on its better sepsis sensitivity. Thus, an increased level of PCT could be linked with disease diagnosis and therapeutics. In this study, we describe the construction of the photoelectrochemical (PEC) PCT immunosensing platform based on it situ grown photo-active CuWO4 nanospheres over reduced graphene oxide layers (CuWO4@rGO). The in situ growth strategy enabled the formation of small nanospheres (diameter of 200 nm), primarily composed of tiny self-assembled CuWO4 nanoparticles (2-5 nm). The synergic coupling of CuWO4 with rGO layers constructed an excellent photo-active heterojunction for photoelectrochemical (PEC) sensing. The platform was then considered for electrocatalytic (EC) mechanism-based detection of PCT, where inhibition of the photocatalytic oxidation signal of ascorbic acid (AA), subsequent to the antibody-antigen interaction, was recorded as the primary signal response. This inhibition detection approach enabled sensitive detection of PCT in a concentration range of 10 pg·mL-1 to 50 ng.mL-1 with signal sensitivity achievable up to 0.15 pg·mL-1. The proposed PEC hybrid (CuWO4@rGO) could further be engineered to detect other clinically important species.


Assuntos
Biomarcadores/análise , Técnicas Biossensoriais , Técnicas Eletroquímicas , Grafite/química , Nanosferas/química , Tungstênio/química , Animais , Bovinos , Cobre , Pró-Calcitonina/análise , Soroalbumina Bovina/química
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