Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Infect Drug Resist ; 17: 2315-2328, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38882657

RESUMEN

Purpose: This study aimed to investigate the antibacterial effects of plasma-activated saline (PAS) on My-cobacterium tuberculosis (Mtb). Methods: We conducted a growth assay on 3 strains of Mtb and an antibiotic sensitivity test on 4 strains of Mtb. Both tests included groups treated with normal saline (NS), PAS, and hydrochloric acid (HCl). The test of antibiotic sensitivity consisted of parallel tests with two concentrations of bacteria suspension: 10-2 and 10-4. The selected antibiotics were rifampicin (RIF), isoniazid (INH), ethambutol (EMB), and streptomycin (SM). The number of bacteria was determined after one month of culture under different conditions. The Kruskal-Wallis test was used to analyze the differences in grouping factors at representative time points. Results: The growth assay indicated that PAS significantly inhibited the growth of 3 strains of Mtb compared with NS and HCl treatment groups. Furthermore, except for the initial observation time point, the remaining three observation time points consistently demonstrate no significant differences between the NS group and the HCl group. The antibiotic sensitivity test of INH, SM, and RIF indicated that PAS could inhibit the growth of antibiotic-resistant Mtb, and the antibiotic sensitivity test of INH and SM with bacterial suspension concentration of 10-2 and SM with bacterial suspension concentration of 10-4 showed statistically different results. The antibiotic sensitivity test of EMB indicated that the growth of Mtb in PAS was slower than that in NS and HCl in both antibiotic-resistant and sensitive Mtb, but there was no statistical difference. Conclusion: The study indicates that PAS contains a significant amount of active substances and exhibits high oxidizability and an acidic pH state. The unique physicochemical properties of PAS significantly delayed the growth of Mtb, compared to the NS and the HCl. PAS not only inhibited the growth of drug-sensitive strains but also significantly enhanced the sensitivity of drug-resistant strains to anti-tuberculosis drugs, which may provide a new therapeutic strategy for the treatment of tuberculosis.

2.
Front Microbiol ; 15: 1367092, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38468858

RESUMEN

Objective: The purpose of this study was to investigate the diagnostic value of urine lipoarabinomannan (LAM) detection based on chemiluminescence assay for pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) in HIV-negative individuals. Methods: A total of 215 patients and 37 healthy individuals were included according to inclusion and exclusion criteria, including 173 cases of PTB and 42 cases of EPTB. Sputum smears, sputum culture, TB-RNA, GeneXpert, and urine LAM results were obtained from all patients before treatment. Using the composite reference standard as the reference, the diagnostic performance of these methods for PTB and EPTB was evaluated, and the diagnostic performance and cost-effectiveness of different combinations were analyzed. Results: In PTB, LAM exhibited the highest sensitivity (55.49%), followed by GeneXpert (44.51%). In EPTB, LAM also had the highest sensitivity (40.48%), followed by GeneXpert (33.33%). When combined with one method, LAM combined with GeneXpert showed the highest sensitivity for both PTB (68.79%) and EPTB (61.9%). When combined with two methods, culture, GeneXpert, and LAM showed the highest sensitivity for both PTB (73.99%) and EPTB (69.05%). In terms of cost-effectiveness analysis, the price of LAM was significantly lower than that of GeneXpert ($129.82 vs. $275.79 in PTB and 275.79 vs. 502.33 in EPTB). Among all combinations, the combination of LAM and sputum smear had the lowest cost, with prices of $124.94 for PTB and $263.72 for EPTB. Conclusion: Urine LAM detection based on chemiluminescence assay can be used as an adjunct diagnostic tool for PTB and EPTB in HIV-negative individuals. This facilitates expanding the current application of urine LAM from solely HIV-positive populations to the general population. LAM detection can overcome the limitations of obtaining clinical samples, and its ease of sample acquisition will be beneficial for its broader application in a larger scope. For economically better-off areas, we recommend using a combination of LAM + GeneXpert+culture for higher sensitivity; for economically disadvantaged areas, LAM + smear microscopy combination can provide a quick and accurate diagnosis of tuberculosis at a lower cost.

3.
Front Neurosci ; 17: 1182509, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37694125

RESUMEN

Background and purpose: Traumatic brain injury (TBI) can cause progressive neuropathology that leads to chronic impairments, creating a need for biomarkers to detect and monitor this condition to improve outcomes. This study aimed to analyze the ability of data-driven analysis of diffusion tensor imaging (DTI) and neurite orientation dispersion imaging (NODDI) to develop biomarkers to infer symptom severity and determine whether they outperform conventional T1-weighted imaging. Materials and methods: A machine learning-based model was developed using a dataset of hybrid diffusion imaging of patients with chronic traumatic brain injury. We first extracted the useful features from the hybrid diffusion imaging (HYDI) data and then used supervised learning algorithms to classify the outcome of TBI. We developed three models based on DTI, NODDI, and T1-weighted imaging, and we compared the accuracy results across different models. Results: Compared with the conventional T1-weighted imaging-based classification with an accuracy of 51.7-56.8%, our machine learning-based models achieved significantly better results with DTI-based models at 58.7-73.0% accuracy and NODDI with an accuracy of 64.0-72.3%. Conclusion: The machine learning-based feature selection and classification algorithm based on hybrid diffusion features significantly outperform conventional T1-weighted imaging. The results suggest that advanced algorithms can be developed for inferring symptoms of chronic brain injury using feature selection and diffusion-weighted imaging.

4.
Microbiol Spectr ; 11(3): e0483622, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37162355

RESUMEN

Prediction of susceptibility to pyrazinamide (PZA) directly from sputum has been challenging. The MeltPro MTB/PZA assay, based on melting curve analysis, can simultaneously detect Mycobacterium tuberculosis and the resistance to PZA from sputum. We aimed to evaluate the MeltPro MTB/PZA assay to predict PZA resistance among rifampin-resistant tuberculosis (RR-TB) patients. We prospectively enrolled RR-TB patients in the registered trials, and their baseline sputum samples were obtained to perform the assay and culture. DNA sequencing of culture isolates was analyzed and used as the reference standard. Sanger sequencing was performed for samples with discrepant results between next-generation sequencing (NGS) and the investigational assay. The main analysis was conducted in the population of patients with interpretable results by both NGS and the assay. A total of 239 patients with RR-TB were screened, and 220 underwent the MeltPro MTB/PZA assay. The assay provided no information for 25 of 220 patients (11.4%). Among the remaining 195 patients, 13 had negative culture or insufficient raw NGS sequencing data, and 15 had indeterminate assay results. A total of 167 patients were included in the main analysis. Against DNA sequencing, the sensitivity, specificity, and negative predictive value of the assay for detecting resistance to PZA were 91.4% (95% confidence interval [CI], 87.1% to 95.6%), 89.9% (95% CI, 85.3% to 94.5%), and 95.2% (95% CI, 91.9% to 98.4%), respectively. In conclusion, the MeltPro MTB/PZA assay is a fast semiautomatic molecular platform to rapidly predict resistance to PZA from sputum and holds promise as a screening tool with satisfactory sensitivity. IMPORTANCE This study evaluated the accuracy of the MeltPro MTB/PZA assay at detecting the presence of PZA resistance through registered clinical trials. Compared to DNA sequencing, the assay had high sensitivity and negative predictive value, suggesting its potential utility as a screening tool in clinical practice. The assay could serve as an ideal primary screening tool in low PZA-resistant M. tuberculosis prevalence settings and could be used as an additional test to identify PZA resistance rapidly and initially in the RR-TB population.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Tuberculosis , Humanos , Pirazinamida/farmacología , Pirazinamida/uso terapéutico , Rifampin/farmacología , Rifampin/uso terapéutico , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Tuberculosis/microbiología , Pruebas de Sensibilidad Microbiana , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Mutación , Farmacorresistencia Bacteriana/genética
6.
ACS Appl Mater Interfaces ; 14(40): 46095-46102, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36174021

RESUMEN

Self-limiting assembly of particles represents the state-of-the-art controllability in nanomanufacturing processes where the assembly stops at a designated stage, providing a desirable platform for applications requiring delicate thickness control such as optics, electronics, and catalytic systems. Most successes in self-limiting assembly are limited to self-assembled monolayers (SAMs) of small molecules on inorganic, chemically homogeneous rigid substrates (e.g., Au and SiO2) through surface-interaction mechanisms. Similar mechanisms, however, cannot achieve a uniform assembly of particles on flexible polymer substrates. The complex configurations and conformations of polymer chains create a surface with nonuniform distributions of chemical groups and phases. In addition, most assembly mechanisms require good solvent wettability, where many desirable but hard-to-wet particles and polymer substrates are excluded. Here, we demonstrate a collision-based self-limiting assembly (CSA) to achieve wafer-scale, full-coverage, close-packed monolayers of hydrophobic particles on hydrophobic polymer substrates in aqueous solutions. The kinetic assembly and self-limiting processes are facilitated and controlled by the combined acoustic and shear fields. We envision many applications in functional coatings and showcase their feasibility in structural coloration. Importantly, such functional coatings can be repaired using CSA, and both particles and polymer substrate can be recycled.

7.
J Mech Behav Biomed Mater ; 131: 105255, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35500495

RESUMEN

In this study, mechanotransduction is investigated through a physics-based viscoelastic model describing the arterial diameter response during a brachial artery flow mediated dilation (BAFMD) test. The study is a significant extension of two earlier studies by the same group, where only the elastic response was considered. Experimental BAFMD responses were collected from 12 healthy volunteers. The arterial wall's elastic and viscous properties were treated as local variable quantities depending on the wall shear stress (WSS) sensed by mechanotransduction. The dimensionless parameters, arising from the model which serve as a quantitative assessment of the artery's physical state, were adjusted to replicate the experimental response. Among those dimensionless parameters, the viscoelastic ratio, which reflects the relative strength of the viscous response compared to its elastic counterpart, is of special relevance to this paper's main conclusion. Based on the results, it is concluded that the arterial wall's mechanical behavior is predominantly elastic, at least in the strict context of the BAFMD test. Recommendations for potential future research and applications are provided.


Asunto(s)
Arteria Braquial , Mecanotransducción Celular , Dilatación , Humanos , Estrés Mecánico , Viscosidad
8.
J Colloid Interface Sci ; 607(Pt 2): 1699-1708, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34592555

RESUMEN

HYPOTHESIS: Quartz is one of the most common but important minerals, and its wettability plays a significant role in affecting various natural and industrial processes. Studies have revealed that different crystal faces of quartz are with different wettabilities, but its mechanism is still vague. EXPERIMENTS AND SIMULATIONS: For specifying the mechanism of crystal face dependent wettability, the contact angles of three different liquids on the crystal faces of α-quartz are measured; the time-of-flight secondary ion mass spectrometry (ToF-SIMS) is employed to establish the crystal surface models; molecular dynamics (MD) simulations with the surface models are performed to understand the wetting behavior at molecular scale. FINDINGS: Based on the contact angle measurements, the wettabilities of different crystal faces of α-quartz are found different, which can be directly attributed to the concentration of hydroxyl group on crystal faces based on ToF-SIMS results. MD simulations yield consistent results with the contact angle order recognized from experiments, revealing that the surface hydroxyl group controls the wettability of α-quartz crystal faces. It is also recognized that the pristine surface atomic arrangement, especially the surface concentration of unsaturated bond (an intrinsic property of α-quartz), is the intrinsic cause of the difference in the concentration of hydroxyl group of the crystal surface.


Asunto(s)
Cuarzo , Espectrometría de Masa de Ion Secundario , Simulación de Dinámica Molecular , Humectabilidad
9.
Neuroimage Clin ; 30: 102681, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34215151

RESUMEN

The detection and association of in vivo biomarkers in white matter (WM) pathology after acute and chronic mild traumatic brain injury (mTBI) are needed to improve care and develop therapies. In this study, we used the diffusion MRI method of hybrid diffusion imaging (HYDI)to detect white matter alterations in patients with chronic TBI (cTBI). 40 patients with cTBI presenting symptoms at least three months post injury, and 17 healthy controls underwent magnetic resonance HYDI. cTBI patients were assessed with a battery of neuropsychological tests. A voxel-wise statistical analysis within the white matter skeleton was performed to study between group differences in the diffusion models. In addition, a partial correlation analysis controlling for age, sex, and time after injury was performed within the cTBI cohort, to test for associations between diffusion metrics and clinical outcomes. The advanced diffusion modeling technique of neurite orientation dispersion and density imaging (NODDI) showed large clusters of between-group differences resulting in lower values in the cTBI across the brain, where the single compartment diffusion tensor model failed to show any significant results. However, the diffusion tensor model appeared to be just as sensitive in detecting self-reported symptoms in the cTBI population using a within-group correlation. To the best of our knowledge this study provides the first application of HYDI in evaluation of cTBI using combined DTI and NODDI, significantly enhancing our understanding of the effects of concussion on white matter microstructure and emphasizing the utility of full characterization of complex diffusion to diagnose, monitor, and treat brain injury.


Asunto(s)
Conmoción Encefálica , Disfunción Cognitiva , Sustancia Blanca , Encéfalo/diagnóstico por imagen , Conmoción Encefálica/complicaciones , Conmoción Encefálica/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/etiología , Imagen de Difusión Tensora , Humanos , Sustancia Blanca/diagnóstico por imagen
10.
J Mech Behav Biomed Mater ; 120: 104606, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34044251

RESUMEN

In this paper, we report a physics based mathematical model to describe the mechanotransduction at the luminal surface of the brachial artery during a flow-mediated dilation (FMD) process. To account for the effect of the released vasodilators in response to the sudden blood flow resurgence, a scalar property is introduced as a signal radially diffusing through the arterial wall, locally affecting its compliance. The model was evaluated on 19 in vivo responses of brachial artery FMD (BAFMD) in 12 healthy subjects. It successfully reproduces the time-dependent dilation of the brachial artery. The predicted artery's outer-to-inner radius ratio was also found to be consistent with the measurements within an acceptable margin of error. Physically meaningful dimensionless parameters quantifying the artery's physical state arose from the model, providing a description to how sensitive or responsive the artery is to the changes of wall shear stress (WSS). Future applications of this model, via incorporating inexpensive, relatively quick, and non-invasive imaging, could potentially help detect early stages of developing forms of cardiovascular diseases.


Asunto(s)
Endotelio Vascular , Vasodilatación , Arteria Braquial , Dilatación , Mecanotransducción Celular , Estrés Mecánico
11.
Infect Dis Poverty ; 10(1): 32, 2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33736710

RESUMEN

BACKGROUND: World Health Organization recommends countries introducing new drug and short treatment regimen for drug resistant tuberculosis (DR-TB) should develop and implement a system for active pharmacovigilance that allows for detection, reporting and management of adverse events. The aim of the study is to evaluate the frequency and severity of adverse events (AEs) of bedaquiline-containing regimen in a cohort of Chinese patients with multidrug-resistant (MDR)/extensively drug-resistant (XDR)-TB based on active drug safety monitoring (aDSM) system of New Drug Introduction and Protection Program (NDIP). METHODS: AEs were prospectively collected with demographic, bacteriological, radiological and clinical data from 54 sites throughout China at patient enrollment and during treatment between February, 2018 and December, 2019. This is an interim analysis including patients who are still on treatment and those that have completed treatment. A descriptive analysis was performed on the patients evaluated in the cohort. RESULTS: By December 31, 2019, a total of 1162 patients received bedaquiline-containing anti-TB treatment. Overall, 1563 AEs were reported, 66.9% were classified as minor (Grade 1-2) and 33.1% as serious (Grade 3-5). The median duration of bedaquiline treatment was 167.0 [interquartile range (IQR): 75-169] days. 86 (7.4%) patients received 36-week prolonged treatment with bedaquiline. The incidence of AEs and serious AEs was 47.1% and 7.8%, respectively. The most frequently reported AEs were QT prolongation (24.7%) and hepatotoxicity (16.4%). There were 14 (1.2%) AEs leading to death. Out of patients with available corrected QT interval by Fridericia's formula (QTcF) data, 3.1% (32/1044) experienced a post-baseline QTcF ≥ 500 ms, and 15.7% (132/839) had at least one change of QTcF ≥ 60 ms from baseline. 49 (4.2%) patients had QT prolonged AEs leading to bedaquiline withdrawal. One hundred and ninety patients reported 361 AEs with hepatotoxicity ranking the second with high occurrence. Thirty-four patients reported 43 AEs of hepatic injury referred to bedaquiline, much lower than that referred to protionamide, pyrazinamide and para-aminosalicylic acid individually. CONCLUSIONS: Bedaquiline was generally well-tolerated with few safety concerns in this clinical patient population without any new safety signal identified. The mortality rate was generally low. These data inform significant positive effect to support the WHO recent recommendations for the wide use of bedaquiline.


Asunto(s)
Antituberculosos/efectos adversos , Antituberculosos/uso terapéutico , Diarilquinolinas/efectos adversos , Diarilquinolinas/uso terapéutico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Adulto , Antituberculosos/administración & dosificación , China/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Seguridad
13.
Front Pharmacol ; 11: 1068, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32973492

RESUMEN

Abelmoschus manihot, an annual herbal flowering plant, is widely distributed throughout eastern Europe and in temperate and subtropical regions of Asia. Its flowers have been traditionally used for the treatment of chronic kidney disease in China. Currently, more than 128 phytochemical ingredients have been obtained and identified from the flowers, seeds, stems, and leaves of A. manihot. The primary components are flavonoids, amino acids, nucleosides, polysaccharides, organic acids, steroids, and volatile oils. A. manihot and its bioactive constituents possess a plethora of biological properties, including antidiabetic nephropathy, antioxidant, antiadipogenic, anti-inflammatory, analgesic, anticonvulsant, antidepressant, antiviral, antitumor, cardioprotective, antiplatelet, neuroprotective, immunomodulatory, and hepatoprotective activities, and have effects on cerebral infarction, bone loss, etc. However, insufficient utilization and excessive waste have already led to a rapid reduction of resources, meaning that a study on the sustainable use of A. manihot is urgent and necessary. Moreover, the major biologically active constituents and the mechanisms of action of the flowers have yet to be elucidated. The present paper provides an early and comprehensive review of the traditional uses, chemical constituents, pharmacological activities, and pharmaceutical, quality control, toxicological, and clinical settings to emphasize the benefits of this plant and lays a solid foundation for further development of A. manihot.

14.
ACS Appl Mater Interfaces ; 12(23): 26342-26349, 2020 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-32420727

RESUMEN

Atmospheric pressure chemical vapor deposition (APCVD) has been used extensively for synthesizing two-dimensional (2D) materials because of its low cost and promise for high-quality monolayer crystal synthesis. However, the understanding of the reaction mechanism and the key parameters affecting the APCVD processes is still in its embryonic stage. Hence, the scalability of the APCVD method in achieving large-scale continuous film remains very poor. Here, we use MoSe2 as a model system and present a fluid guided growth strategy for understanding and controlling the growth of 2D materials. Through the integration of experiment and computational fluid dynamics (CFD) analysis in the full-reactor scale, we identified three key parameters, precursor mixing, fluid velocity, and shear stress, which play a critical role in the APCVD process. By modifying the geometry of the growth setup to enhance precursor mixing and decrease nearby velocity shear rate and adjusting flow direction, we have successfully obtained inch-scale monolayer MoSe2. This unprecedented success of achieving scalable 2D materials through fluidic design lays the foundation for designing new CVD systems to achieve the scalable synthesis of nanomaterials.

15.
Langmuir ; 36(20): 5608-5617, 2020 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-32354211

RESUMEN

The significant size distribution of as-synthesized nanomaterials presents a challenge for reproducable and reliable applications. In this paper, we report a fluidic-assisted sorted assembly method in which nanomaterial sorting and enhanced assembly can be achieved simultaneously. As a proof of concept, a two-dimensional (2D) graphene flake, with a large size variation, was chosen as the target nanomaterial system. This study synergizes a novel fluidic assembly design, suspending a rotating disk over a polydimethylsiloxane (PDMS) substrate, and a computational fluid dynamics (CFD) model using Ansys CFX to disclose the mechanism of sorted assembly. By controlling the rotating speed and the gap between the disk and the substrate, the flow field is altered. In contrast to centrifugal sorting, where larger particles move outward, in this study, the size of assembled graphene flake (average lateral size, Xc) reduces significantly from the center (Xc = 3 µm) to the edge of the disk (Xc = 2 µm). The particle sorting process is dictated by the fluid shear-stress, with higher shear-stress leading to smaller particles, while the assembly process is mainly dominated by the pressure field with higher pressure magnitude leading to better assembly. Near the edge of the disk, enhanced particle sorting is coupled with an enhanced assembly where a continuous graphene film with smaller Xc can be formed. To prove the potential application of this method, an ultrasensitive strain sensor with one of the lowest detection limits, 0.02%, is demonstrated. This research presents a novel route toward large-scale and cost-effective manufacturing of nanomaterial-based flexible electronics.

16.
Iran J Immunol ; 17(1): 1-13, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32224537

RESUMEN

BACKGROUND: Patient immune status might be indicative of the variance in bacterial genetics in drug-resistant tuberculous pleuritis and could be used for predicting the risk of multi-drug resistant tuberculous pleuritis (MDR-TB). OBJECTIVE: To determine the significance of Th2/Th1 ratio and concentration of PD-L1 in the pleural effusions for prediction of MDR-TB. METHODS: We measured the ratio of Th2 to Th1 T cells from pleural effusions in 373 tuberculous pleuritis patients. We also measured the concentration of programmed death ligand-1 (PD-L1) in the pleural effusions of these patients. Afterwards, we determined the optimal cut-off value for predicting the occurrence of multi-drug resistant tuberculous based on the Youden index, diagnostic evaluation test, and receiver operation curve. Multiple logistic analysis was employed to identify the independent risk factors for MDR-TB occurrence. RESULTS: The area under the curve (AUC) of the Th2 to Th1 ratio was 0.66 and the concentration of PD-L1 was 0.71. Based on the combined detection of PD-L1 concentration in pleural effusion and the Th2 to Th1 ratio, our AUC was 0.81 and had a specificity of 0.92. Only a combined detection was able to identify patients developing multidrug-resistant tuberculosis. Multiple logistic analysis showed that a high concentration of PD-L1 and a high Th2 to Th1 ratio in pleural effusions were indicative of an immunocompromised status. Therefore, these measurements might be independent risk factors for the occurrence of multidrug-resistant tuberculous. CONCLUSION: Evaluation of immune status based on PD-L1 pleural concentration and Th2 to Th1 ratio might predict the risk of MDR-TB occurrence.


Asunto(s)
Antígeno B7-H1/metabolismo , Derrame Pleural , Células TH1/inmunología , Células Th2/inmunología , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Pleural/diagnóstico , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Derrame Pleural/inmunología , Derrame Pleural/metabolismo , Tuberculosis Resistente a Múltiples Medicamentos/inmunología , Tuberculosis Resistente a Múltiples Medicamentos/metabolismo , Tuberculosis Pleural/inmunología , Tuberculosis Pleural/metabolismo
17.
J Mech Behav Biomed Mater ; 107: 103756, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32278310

RESUMEN

In this paper, a physics-based mathematical model is developed to describe the transient behavior of the brachial artery during the Flow Mediated Dilation (FMD) test. The change of the artery's diameter was collected for 7 cases via in vivo, non-invasive ultrasound imaging. A theoretical model was developed to capture the response of the blood vessel to the change of the blood flow, in which the vessel's compliance is modeled as a function of the wall shear stress (WSS). The theory precisely captures the key feature of the mechanotransduction process, which a conventional viscoelastic model fails to describe. Three characteristic dimensionless parameters were obtained from the model, quantifying the physical state of the artery and related to the cardiovascular health. The transient physics, manifested in the two-way (where both arterial compliance and blood flow conditions affect each other) Fluid-Structure Interaction (FSI) process, present an interesting opportunity to explore the nature of living materials making up the arterial walls, which would in turn lead to a better understanding and therefore detection of the onset of some forms of cardiovascular diseases (CVD).


Asunto(s)
Arteria Braquial , Mecanotransducción Celular , Arteria Braquial/diagnóstico por imagen , Dilatación , Hemodinámica , Física , Vasodilatación
18.
J Mech Behav Biomed Mater ; 102: 103504, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31670258

RESUMEN

In this paper, the interstitial fluid flow in skeletal muscle endomysium was examined using an in-situ indentation testing in combination with theoretical modelling. The objective was to understand the transport properties of the three-dimensional and highly hierarchical muscular interstitial matrices, which play important roles in muscle-bone cross-talk and signaling during musculoskeletal development and maintenance. Gastrocnemius muscles from four 3-month old calves were harvested and subjected to a creeping test using a custom-designed device. The experiments, in combination with an anatomy-based theoretical model, were used to capture the spatial-temporal response of the skeletal muscle to external impacts. For the first time, the detailed load-induced interstitial fluid pressurization in the muscle endomyseal space was obtained. The relative contribution from the solid muscle fibers and the interstitial fluid to the temporal loading response was captured. The paper presented herein provides important information regarding the mechanical environment within the muscle tissue, which could help the future study of muscle's response to forces and its subsequent signaling to surrounding tissues in vivo.


Asunto(s)
Líquido Extracelular , Fibras Musculares Esqueléticas , Animales , Huesos , Bovinos , Músculo Esquelético , Fenómenos Físicos
20.
Zhonghua Jie He He Hu Xi Za Zhi ; 37(6): 421-6, 2014 Jun.
Artículo en Chino | MEDLINE | ID: mdl-25200041

RESUMEN

OBJECTIVE: By using the cell wall component of Mycobacterium tuberculosis 19 000 lipoprotein (P19) and curcumin (CUR) acting on the human macrophage cell line WBC264-9C, and by the blocking of the p38 mitogen-activated protein kinases (p38 MAPK) signaling pathway, we wanted to investigate the effect of curcumin on P19-induced inflammatory responses and apoptosis in human macrophages and the potential underlying molecular mechanisms. METHODS: P19 and CUR were used to stimulate human macrophages for 48 h. Their effects on growth inhibition and on apoptosis in macrophages were observed. The combination effect of CUR with P19 on the expression of IL-1ß, IL-6, TNF-α, STAT3, P53, Bax, Bcl2 and phspho-p38 MAPK levels were also observed. By using the antagonist of p38 MAPK, the effect of CUR on P19-induced expression of inflammatory cytokines and apoptotic proteins were investigated. RESULTS: Twenty and 40 µmol/L of CUR inhibited the growth of macrophages by (10.1 ± 2.3)% and (19.0 ± 2.7)%. The growth inhibition rate of macrophages in the controls, P19 and P19+CUR treated groups were (6.7 ± 4.2)%, (45.4 ± 3.6)% and (32.1 ± 3.0)%, respectively. The P19-induced growth inhibition was significantly attenuated by CUR treatment (q = 9.75, P < 0.01). The expression of IL-1ß, IL-6, TNF-α and STAT3 mRNA (13.2 ± 2.7, 33.5 ± 1.1, 3.3 ± 2.2, 0.9 ± 1.7) were significantly lower than P19-treated groups (21.8 ± 3.5, 14.3 ± 1.4, 6.1 ± 3.6, 4.5 ± 3.4) (q values were ranged from 7.18 to 3.22, all P < 0.05). Furthermore, P53 protein (94.3 ± 0.2; q = 7.05, P < 0.01) and Bax (70.8 ± 8.7; q = 7.66, P < 0.01) levels were decreased in CUR+P19 group as compared with P19 group (320.2 ± 0.2 and 182.6 ± 1.2). Blockade of p38 MAPK accompanied with CUR and P19 induced significantly lower levels of IL-6 mRNA (34.9 ± 1.5, q = 2.36, P < 0.05) and Bax/Bcl2 protein (0.36 ± 0.09; q = 3.50, P < 0.05) expression, as compared with the controls (69.9 ± 1.8 and 0.71 ± 0.11). CONCLUSIONS: P19 increased the expression of inflammatory cytokines and promoted the apoptosis of macrophages possibly through the activation of p38 MAPK signaling pathway. Low concentration of curcumin may play a protective effect against P19-induced immune responses by inhibiting the p38 MAPK pathway in macrophages.


Asunto(s)
Proteínas Bacterianas/farmacología , Curcumina/farmacología , Macrófagos/efectos de los fármacos , Mycobacterium tuberculosis/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Citocinas/metabolismo , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Lipoproteínas/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Mycobacterium tuberculosis/genética , Plantas Medicinales/química , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...