Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 283
Filtrar
1.
Sci Rep ; 14(1): 9375, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654100

RESUMO

We propose an integrated methodology for the design and fabrication of 3D micromodels that are suitable for the pore-scale study of transport processes in macroporous materials. The micromodels, that bear the pore-scale characteristics of sandstone, such as porosity, mean pore size, etc, are designed following a stochastic reconstruction algorithm that allows for fine-tuning the porosity and the correlation length of the spatial distribution of the solid material. We then construct a series of 3D micromodels at very fine resolution (i.e. 16 µ m) using a state-of-the-art 3D printing infrastructure, specifically a ProJet MJP3600 3D printer, that utilizes the Material Jetting technology. Within the technical constraints of the 3D printer resolution, the fabricated micromodels represent scaled-up replicas of natural sandstones, that are suitable for the study of the scaling between the permeability, the porosity and the mean pore size. The REV- and pore-scale characteristics of the resulting physical micromodels are recovered using a combination of X-ray micro-CT and microfluidic studies. The experimental results are then compared with single-phase flow simulations at pore-scale and geostatistic models in order to determine the effects of the design parameters on the intrinsic permeability and the spatial correlation of the velocity profile. Our numerical and experimental measurements reveal an excellent match between the properties of the designed and fabricated 3D domains, thus demonstrating the robustness of the proposed methodology for the construction of 3D micromodels with fine-tuned and well-controlled pore-scale characteristics. Furthermore, a pore-scale numerical study over a wider range of 3D digital domain realizations reveals a very good match of the measured permeabilities with the predictions of the Kozeny-Carman formulation based on a single control parameter, k 0 , that is found to have a practically constant value for porosities ϕ ≥ 0.2 . This, in turn, enables us to customize the sample size to meet REV constraints, including enlarging pore morphology while considering the Reynolds number. It is also found that at lower porosities there is a significant increase in the fraction of the non-percolating pores, thus leading to different k 0 , as the porosity approaches a numerically determined critical porosity value, ϕ c , where the domain is no longer percolating.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38639309

RESUMO

OBJECTIVE: In this study, we examine how impairments in vision, hearing, touch, and olfaction relate to depression in older adults, considering both individual and multisensory impairments (MSIs). STUDY DESIGN: Analysis of cross-sectional data from a longitudinal investigation involving black and white older adults aged 70 to 79 at enrollment. SETTING: We studied 1640 black and white participants in the Health ABC study using complete sensory evaluation data from years 3 to 5. METHODS: Our MSI assessment utilized data obtained for visual acuity, hearing perception, olfactory performance, and tactile function. We performed multivariable logistic regression analyses to examine the associations between the presence of individual and MSIs and depression which was defined as the presence of antidepressants prescribed for depression, or a Center for Epidemiological Studies Depression Scale score of greater than 10. RESULTS: We observed a possible dose-response relationship between the number of sensory impairments and depression. In adjusted models, when compared to no impairments, vision (odds ratio [OR] = 1.45, 95% confidence interval [CI]: 1.09-1.93) and hearing impairments (OR = 1.49, 95% CI: 1.11-1.99) were significantly associated with depression, whereas olfaction (OR = 1.11, 95% CI: 0.83-1.47) and tactile impairments (OR = 1.28, 95% CI: 0.96-1.70) were not. Participants with 3 sensory impairments had a higher rate of depression (OR = 2.05, 95% CI: 1.22-3.54) compared to those without impairments, and this risk increased further for those with 4 sensory impairments (OR = 2.95, 95% CI: 1.48-5.88). CONCLUSION: The findings suggest that individuals with MSI represent a high-risk population for depression, warranting close monitoring to screen for depression. The study emphasizes the importance of considering multiple sensory impairments in the context of mental health and supports the early identification and monitoring of depression in this population.

3.
Int J Nanomedicine ; 19: 3031-3044, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38562612

RESUMO

Purpose: Peripheral nerve damage lacks an appropriate diagnosis consistent with the patient's symptoms, despite expensive magnetic resonance imaging or electrodiagnostic assessments, which cause discomfort. Ultrasonography is valuable for diagnosing and treating nerve lesions; however, it is unsuitable for detecting small lesions. Poly(vanillin-oxalate) (PVO) nanoparticles are prepared from vanillin, a phytochemical with antioxidant and anti-inflammatory properties. Previously, PVO nanoparticles were cleaved by H2O2 to release vanillin, exert therapeutic efficacy, and generate CO2 to increase ultrasound contrast. However, the role of PVO nanoparticles in peripheral nerve lesion models is still unknown. Herein, we aimed to determine whether PVO nanoparticles can function as contrast and therapeutic agents for nerve lesions. Methods: To induce sciatic neuritis, rats were administered a perineural injection of carrageenan using a nerve stimulator under ultrasonographic guidance, and PVO nanoparticles were injected perineurally to evaluate ultrasonographic contrast and therapeutic effects. Reverse transcription-quantitative PCR was performed to detect mRNA levels of pro-inflammatory cytokines, ie, tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2. Results: In the rat model of sciatic neuritis, PVO nanoparticles generated CO2 bubbles to increase ultrasonographic contrast, and a single perineural injection of PVO nanoparticles suppressed the expression of tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2, reduced the expression of F4/80, and increased the expression of GAP43. Conclusion: The results of the current study suggest that PVO nanoparticles could be developed as ultrasonographic contrast agents and therapeutic agents for nerve lesions.


Assuntos
Benzaldeídos , Nanopartículas , Neuropatia Ciática , Ratos , Humanos , Animais , Peróxido de Hidrogênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Dióxido de Carbono , Ciclo-Oxigenase 2/metabolismo , Neuropatia Ciática/metabolismo , Neuropatia Ciática/patologia , Nanopartículas/química , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/metabolismo
4.
J Control Release ; 369: 351-362, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38552963

RESUMO

Polymeric prodrug nanoparticles have gained increasing attention in the field of anticancer drug delivery because of their dual functions as a drug carrier and a therapeutic agent. Doxorubicin (DOX) is a highly effective chemotherapeutic agent for various cancers but causes cardiotoxicity. In this work, we developed polymeric prodrug (pHU) nanoparticles that serve as both a drug carrier of DOX and a therapeutic agent. The composition of pHU includes antiangiogenic hydroxybenzyl alcohol (HBA) and ursodeoxycholic acid (UDCA), covalently incorporated through hydrogen peroxide (H2O2)-responsive peroxalate. To enhance cancer cell specificity, pHU nanoparticles were surface decorated with taurodeoxycholic acid (TUDCA) to facilitate p-selectin-mediated cancer targeting. TUDCA-coated and DOX-loaded pHU nanoparticles (t-pHUDs) exhibited controlled release of DOX triggered by H2O2, characteristic of the tumor microenvironment. t-pHUDs also effectively suppressed cancer cell migration and vascular endothelial growth factor (VEGF) expression in response to H2O2. In animal studies, t-pHUDs exhibited highly potent anticancer activity. Notably, t-pHUDs, with their ability to accumulate preferentially in tumors due to the p-selectin targeting, surpassed the therapeutic efficacy of equivalent DOX and pHU nanoparticles alone. What is more, t-pHUDs significantly suppressed VEGF expression in tumors and mitigated hepato- and cardiotoxicity of DOX. Given their cancer targeting ability, enhanced therapeutic efficacy and minimized off-target toxicity, t-pHUDs present an innovative and targeted approach with great translational potential as an anticancer therapeutic agent.

5.
J Neurosci ; 44(14)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38360746

RESUMO

An increasing number of pathogenic variants in presynaptic proteins involved in the synaptic vesicle cycle are being discovered in neurodevelopmental disorders. The clinical features of these synaptic vesicle cycle disorders are diverse, but the most prevalent phenotypes include intellectual disability, epilepsy, movement disorders, cerebral visual impairment, and psychiatric symptoms ( Verhage and Sørensen, 2020; Bonnycastle et al., 2021; John et al., 2021; Melland et al., 2021). Among this growing list of synaptic vesicle cycle disorders, the most frequent is STXBP1 encephalopathy caused by de novo heterozygous pathogenic variants in syntaxin-binding protein 1 (STXBP1, also known as MUNC18-1; Verhage and Sørensen, 2020; John et al., 2021). STXBP1 is an essential protein for presynaptic neurotransmitter release. Its haploinsufficiency is the main disease mechanism and impairs both excitatory and inhibitory neurotransmitter release. However, the disease pathogenesis and cellular origins of the broad spectrum of neurological phenotypes are poorly understood. Here we generate cell type-specific Stxbp1 haploinsufficient male and female mice and show that Stxbp1 haploinsufficiency in GABAergic/glycinergic neurons causes developmental delay, epilepsy, and motor, cognitive, and psychiatric deficits, recapitulating majority of the phenotypes observed in the constitutive Stxbp1 haploinsufficient mice and STXBP1 encephalopathy. In contrast, Stxbp1 haploinsufficiency in glutamatergic neurons results in a small subset of cognitive and seizure phenotypes distinct from those caused by Stxbp1 haploinsufficiency in GABAergic/glycinergic neurons. Thus, the contrasting roles of excitatory and inhibitory signaling reveal GABAergic/glycinergic dysfunction as a key disease mechanism of STXBP1 encephalopathy and suggest the possibility to selectively modulate disease phenotypes by targeting specific neurotransmitter systems.


Assuntos
Encefalopatias , Epilepsia , Transtornos do Neurodesenvolvimento , Animais , Feminino , Masculino , Camundongos , Encefalopatias/genética , Epilepsia/genética , Neurônios GABAérgicos/metabolismo , Proteínas Munc18/genética , Proteínas Munc18/metabolismo , Transtornos do Neurodesenvolvimento/genética , Neurotransmissores
6.
Environ Sci Technol ; 58(6): 2728-2738, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38232385

RESUMO

Understanding geochemical dissolution in porous materials is crucial, especially in applications such as geological CO2 storage. Accurate estimation of reaction rates enhances predictive modeling in geochemical-flow simulations. Fractured porous media, with distinct transport time scales in fractures and the matrix, raise questions about fracture-matrix interface dissolution rates compared to bulk dissolution rate and the scale-dependency of reaction rate averaging. Our investigation delves into these factors, studying the impact of flow rate and mineralogy on interface dissolution patterns. By injecting carbonated water into carbonate rock samples containing a central channel (mimicking fracture hydrodynamics), our study utilized µCT X-ray imaging at 3.3 µm spatial resolution to estimate the reaction rate and capture the change in pore morphology. Results revealed dissolution rates significantly lower (up to 4 orders of magnitude) than batch experiments. Flow rate notably influenced fracture profiles, causing uneven enlargement at low rates and uniform widening at higher ones. Ankerite presence led to a dissolution-altered layer on the fracture surface, showing high permeability and porosity without greatly affecting the dissolution rate, unlike clay-rich carbonates. This research sheds light on controlling factors influencing dissolution in subsurface environments, critical for accurate modeling in diverse applications.


Assuntos
Dióxido de Carbono , Carbonatos , Microtomografia por Raio-X
7.
Muscle Nerve ; 69(4): 498-503, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38294129

RESUMO

INTRODUCTION/AIMS: Oxaliplatin is a platinum-based anti-cancer drug widely used in colorectal cancer patients, but it may cause peripheral neuropathy. As one of the main causes of oxaliplatin-induced peripheral neuropathy (OPN) is oxidative stress, which is also a key factor causing diabetic peripheral neuropathy (DPN), the aim of this study was to evaluate the preventive effects of alpha-lipoic acid (ALA) and epalrestat (EP), which are used for the treatment of DPN, in an OPN zebrafish model. METHODS: Tg(nbt:dsred) transgenic zebrafish, with sensory nerves in the peripheral lateral line, were treated with oxaliplatin, oxaliplatin/EP, and oxaliplatin/ALA for 4 days. A confocal microscope was used to visualize and quantify the number of axon bifurcations in the distal nerve ending. To analyze the formation of synapses on sensory nerve terminals, quantification of membrane-associated guanylate kinase (MAGUK) puncta was performed using immunohistochemistry. RESULTS: The number of axon bifurcations and intensity of MAGUK puncta were significantly reduced in the oxaliplatin-treated group compared with those in the embryo medium-treated group. In both the oxaliplatin/EP and oxaliplatin/ALA-treated groups, the number of axon bifurcations and intensity of MAGUK puncta were greater than those in the oxaliplatin-treated group (p < .0001), and no significant difference was observed between larvae treated with oxaliplatin/ALA 1 µM and oxaliplatin/EP 1 µM (p = .4292). DISCUSSION: ALA and EP have protective effects against OPN in zebrafish. Our findings show that ALA and EP can facilitate more beneficial treatment for OPN.


Assuntos
Antineoplásicos , Doenças do Sistema Nervoso Periférico , Rodanina/análogos & derivados , Tiazolidinas , Ácido Tióctico , Animais , Humanos , Ácido Tióctico/farmacologia , Ácido Tióctico/uso terapêutico , Peixe-Zebra , Oxaliplatina/toxicidade , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Doenças do Sistema Nervoso Periférico/prevenção & controle , Antineoplásicos/toxicidade
8.
Plast Reconstr Surg ; 153(1): 10e-24e, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37010460

RESUMO

BACKGROUND: Implant-based breast reconstruction has evolved over time. However, the effects of prepectoral breast reconstruction (PBR) compared with those of subpectoral breast reconstruction (SBR) have not been clearly defined. Therefore, this study aimed to compare the occurrence of surgical complications between PBR and SBR to determine the procedure that is effective and relatively safe. METHODS: The PubMed, Cochrane Library, and EMBASE databases were searched for studies published until April of 2021 comparing PBR and SBR following mastectomy. Two authors independently assessed the risk of bias. General information on the studies and surgical outcomes were extracted. Among 857 studies, 34 and 29 were included in the systematic review and meta-analysis, respectively. Subgroup analysis was performed to clearly compare the results of patients who underwent postmastectomy radiation therapy. RESULTS: Pooled results showed that prevention of capsular contracture (OR, 0.57; 95% CI, 0.41 to 0.79) and infection control (OR, 0.73; 95% CI, 0.58 to 0.92) were better with PBR than with SBR. Rates of hematoma, implant loss, seroma, skin-flap necrosis, and wound dehiscence were not significantly different between PBR and SBR. PBR considerably improved postoperative pain, BREAST-Q score, and upper arm function compared with SBR. Among postmastectomy radiation therapy patients, the incidence rates of capsular contracture were significantly lower in the PBR group than in the SBR group (OR, 0.14; 95% CI, 0.05 to 0.35). CONCLUSIONS: The results showed that PBR had fewer postoperative complications than SBR. The authors' meta-analysis suggests that PBR could be used as an alternative technique for breast reconstruction in appropriate patients.


Assuntos
Implante Mamário , Implantes de Mama , Neoplasias da Mama , Contratura , Mamoplastia , Humanos , Feminino , Neoplasias da Mama/etiologia , Mastectomia/efeitos adversos , Mastectomia/métodos , Implante Mamário/efeitos adversos , Implante Mamário/métodos , Mamoplastia/efeitos adversos , Mamoplastia/métodos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Contratura/etiologia , Implantes de Mama/efeitos adversos
9.
J Control Release ; 365: 286-300, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992875

RESUMO

Multidrug resistance (MDR) is an inevitable clinical problem in chemotherapy due to the activation of abundant P-glycoprotein (P-gp) that can efflux drugs. Limitations of current cancer therapy highlight the need for the development of a comprehensive cancer treatment strategy, including drug-resistant cancers. Small extracellular vesicles (sEVs) possess significant potential in surmounting drug resistance as they can effectively evade the efflux mechanism and transport small molecules directly to MDR cancer cells. One mechanism mediating MDR in cancer cells is sustaining increased levels of reactive oxygen species (ROS) and maintenance of the redox balance with antioxidants, including glutathione (GSH). Herein, we developed GSH-depleting benzoyloxy dibenzyl carbonate (B2C)-encapsulated sEVs (BsEVs), which overcome the efflux system to exert highly potent anticancer activity against human MDR ovarian cancer cells (OVCAR-8/MDR) by depleting GSH to induce oxidative stress and, in turn, apoptotic cell death in both OVCAR-8/MDR and OVCAR-8 cancer cells. BsEVs restore drug responsiveness by inhibiting ATP production through the oxidation of nicotinamide adenine dinucleotide with hydrogen (NADH) and inducing mitochondrial dysfunction, leading to the dysfunction of efflux pumps responsible for drug resistance. In vivo studies showed that BsEV treatment significantly inhibited the growth of OVCAR-8/MDR and OVCAR-8 tumors. Additionally, OVCAR-8/MDR tumors showed a trend towards a greater sensitivity to BsEVs compared to OVCAR tumors. In summary, this study demonstrates that BsEVs hold tremendous potential for cancer treatment, especially against MDR cancer cells.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Antineoplásicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Preparações Farmacêuticas , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico
10.
IEEE Trans Biomed Circuits Syst ; 17(6): 1214-1226, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38096094

RESUMO

This article presents a fully-integrated dielectrophoresis (DEP)-assisted multi-functional CMOS biosensor array chip with 4096 working electrodes (WEs), 12288 photodiodes (PDs), reference electrodes (REs), and counter electrodes (CEs), while each WE and photodiode can be reconfigured to support on-chip DEP actuation, electrochemical potentiostat, optical shadow imaging, and complex impedance sensing. The proposed CMOS biosensor is an example of an actuation-assisted label-free biosensor for the rapid sensing of low-concentration analytes. The DEP actuator of the proposed CMOS biosensor does not require any external electrode. Instead, on-chip WE pairs can be re-used for DEP actuation to simplify the sensor array design. The CMOS biosensor is implemented in a standard 130-nm BiCMOS process. Theoretical analyses and finite element method (FEM) simulations of the on-chip DEP operations are conducted as proof of concept. Biological assay measurements (DEP actuation/electrochemical potentiostat/impedance sensing) with E.coli bacteria and microbeads (optical shadow imaging) demonstrate rapid detection of low-concentration analytes and simultaneous manipulation and detection of large particles. The on-chip DEP operations draw the analytes closer to the sensor electrode surface, which overcomes the diffusion limit and accelerates low-concentration analyte sensing. Moreover, the DEP-based movement of large particles can be readily detected by on-chip photodiode arrays to achieve close-loop manipulation and sensing of particles and droplets. These show the unique advantages of the DEP-assisted multi-functional biosensor.


Assuntos
Técnicas Biossensoriais , Eletrodos
11.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38065175

RESUMO

An existing open and modular designed micro X-Ray Computed Tomography (µXRCT) system is extended by a test rig in order to combine mechanical and hydro-mechanical experiments with µXRCT characterization. The aim of the system is to cover the complete resolution range of the underlying µXRCT system in combination with a broad load capacity range. A characteristic feature of the developed setup is that it consists mainly of standard components. This makes the shown test rig potentially interesting for other researchers considering extending an existing µXRCT system with an apparatus for mechanical and hydro-mechanical in situ testing. For the load frame, an uniaxial 10 kN universal testing machine with a digital control system was employed, which was extended by two aligned rotational stages. The uniaxial load capacity is ±3.1 kN and can be combined with torque moments of up to ±15 N m both limited by the used rotational stages. The setup is designed in such a way that different x-ray transparent cells (flow cells, oedometer cells, triaxial cells, etc.) can be integrated to generate three-dimensional stress/strain states as required for porous media research. Three applications demonstrate the possible versatile use of the system. As part of these examples, we show how corresponding x-ray transparent cells are designed and implemented. Finally, we discuss the presented approach's technical advantages and disadvantages and suggest improvements.

12.
Int J Mol Sci ; 24(24)2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38139091

RESUMO

Chronic rhinosinusitis (CRS) is characterized by inflammatory cell infiltration in the sinonasal mucosa. Eosinophil and neutrophil extracellular traps (EETs and NETs, respectively) are prominently found in CRS. This study aimed to investigate the effect of airborne fungi, Alternaria alternata and Aspergillus fumigatus, on EET and NET formation. Nasal epithelial cells, eosinophils, and neutrophils were isolated from eosinophilic CRS (ECRS), non-ECRS (NECRS), and healthy control. We determined eosinophil and neutrophil transepithelial migration after fungal treatment. We then determined the release of EETs and NETs by fungi using Sytox Green staining and determined the role of reactive oxygen species (ROS) using ROS inhibitors. We identified more abundant EETs and NETs in ECRS than in NECRS. A. alternata and A. fumigatus enhanced eosinophil and neutrophil transepithelial migration. A. fumigatus strongly induced EET and NET formation in CRS and, simultaneously, suppressed fungal metabolic activity. EET formation in CRS is associated with nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase and NET formation with NADPH-oxidase and mitochondrial ROS. A. fumigatus, but not A. alternata, induced EET and NET formation, and peripheral blood eosinophils and neutrophils exhibited different immune responses against A. fumigatus following the inflammatory status of the host. Aspergillus-fumigatus-induced EET and NET formation plays a crucial role in CRS pathogenesis.


Assuntos
Armadilhas Extracelulares , 60523 , Sinusite , Humanos , Neutrófilos/metabolismo , Armadilhas Extracelulares/metabolismo , Eosinófilos , Espécies Reativas de Oxigênio/metabolismo , NADP/metabolismo , Doença Crônica , Sinusite/metabolismo , Aspergillus , Aspergillus fumigatus , NADPH Oxidases/metabolismo
13.
Cell Rep ; 42(11): 113351, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37910504

RESUMO

Genome-wide association studies (GWASs) have identified numerous variants associated with polygenic traits and diseases. However, with few exceptions, a mechanistic understanding of which variants affect which genes in which tissues to modulate trait variation is lacking. Here, we present genomic analyses to explain trait heritability of blood pressure (BP) through the genetics of transcriptional regulation using GWASs, multiomics data from different tissues, and machine learning approaches. Approximately 500,000 predicted regulatory variants across four tissues explain 33.4% of variant heritability: 2.5%, 5.3%, 7.7%, and 11.8% for kidney-, adrenal-, heart-, and artery-specific variants, respectively. Variation in the enhancers involved shows greater tissue specificity than in the genes they regulate, suggesting that gene regulatory networks perturbed by enhancer variants in a tissue relevant to a phenotype are the major source of interindividual variation in BP. Thus, our study provides an approach to scan human tissue and cell types for their physiological contribution to any trait.


Assuntos
Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Humanos , Locos de Características Quantitativas/genética , Pressão Sanguínea/genética , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Variação Genética
14.
Diagnostics (Basel) ; 13(21)2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37958215

RESUMO

Ultrasound contrast agents are clinically used for diagnosis of internal organs, but ultrasound contrast agents are rarely applied clinically in musculoskeletal disorders. Our study aims to comparatively analyze the differences between ultrasonographic images through peri-injury injection of the clinically used microbubble and researched nanoparticle contrast agents in various muscular injury models. To compare contrast-enhanced images in different muscle injury models, we prepared groups of rats with sham, laceration, punch, contusion, and toxin injection injuries. We measured H2O2 levels using the Amplex Red assay by extracting tissue from the damaged area. As comparative contrast agents, SonoVue®, a commercially available microbubble contrast agent, and poly(vanillinoxalte) (PVO) nanoparticles, which are H2O2-responsive nanoparticles, were used. The difference in contrast between the two contrast agents was recorded as an ultrasound movie, and J-image software 1.53p was used to quantify and analyze the maximum and minimum echogenicity values of the images after contrast enhancement. In the Amplex red assay for the highest H2O2 level in each muscle injury model, the maximum level showed 24 h after the modeling. In the sham rats, PVO injection showed no increased echogenicity except at the needle insertion site, but SonoVue® injection showed increased echo signal throughout the injected muscle immediately after injection. One day after the preparation of the lesion, PVO and SonoVue® were injected into the lesion site and ultrasound was performed on the lesion site. After the injection of PVO nanoparticles, contrast enhancement was observed at the lesion site immediately. SonoVue® injections, on the other hand, showed a widespread pattern of echo signals and an increase in echo retention only at the lesion site over time, but this was not clear. There were statistically significant differences between the highest and lowest echogenicity in PVO and SonoVue® contrast-enhanced images in all models. Contrast enhancement lasted more than 3 h in the PVO injection, but disappeared within 3 h in the SonoVue® injection. PVO nanoparticles showed the possibility of physiologic contrast by CO2 generated by conjugation with H2O2 generated by muscle injuries, and SonoVue® injection observed the possibility of microbubble contrast as a contrast agent with a pooling effect that lasts longer on the lesion. Further research is needed to investigate the use of various ultrasound contrast agents, including nanoparticles, in musculoskeletal disorders, as well as the potential for further utilities of microbubble contrast agents.

15.
Front Oncol ; 13: 1211593, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38023138

RESUMO

Background: Sarcopenia is characterized by the loss of skeletal muscle mass and power. Preoperative sarcopenia may be associated with an increased risk of postoperative complications after autologous free-flap breast reconstruction surgery; however, this relationship is controversial. Objectives: This study aimed to determine whether preoperative sarcopenia is associated with a high complication rate in patients undergoing autologous free-flap breast reconstruction. Methods: Patients who underwent autologous free-flap breast reconstruction at our hospital between 2019 and 2021 were included in the study. Data on significant complications requiring surgical intervention were retrospectively collected from the medical records. Sarcopenia was defined as having a skeletal muscle index value <41 cm2/m2. The skeletal muscle index was calculated by dividing the sum of the psoas and iliopsoas muscle areas at the level of the third lumbar vertebra by the patient's height in meters squared. The relationship between preoperative sarcopenia and postoperative complications was investigated using an inverse probability of treatment weighting (IPTW) analysis. Results: Among the 203 participants, 90 (44.33%) had preoperative sarcopenia. The general patient characteristics were similar between the sarcopenia and non-sarcopenia groups after IPTW adjustment. Sarcopenia did not significantly increase the risk of flap failure or emergency surgery related to breast reconstruction before IPTW adjustment. However, after IPTW adjustment, the rates of recipient site infection and hematoma were significantly higher in participants with sarcopenia than in those without sarcopenia (p < 0.001 and p = 0.014, respectively). Conclusion: Preoperative sarcopenia may influence certain complications of autologous free-flap breast reconstruction surgery.

16.
J Health Econ ; 92: 102829, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37865028

RESUMO

We use Nielsen Homescan data to examine whether the incidence of cigarette taxes on menthol products varies with race. We find that taxes are shifted at significantly lower rates to Black smokers of menthol cigarettes than any other smokers. One possible explanation is that the industry targets price promotions to Black menthol smokers because they tend to be more responsive to cigarette prices relative to other smokers. We find evidence that Black smokers receive significantly more price discounts for menthol products than white menthol smokers. Our findings indicate that increasing cigarette taxes would effectively reduce menthol smoking among Black Americans because tax pass-through rate for Black menthol smokers is still substantially above zero.


Assuntos
Mentol , Produtos do Tabaco , Humanos , Incidência , Fumar/epidemiologia , Impostos
17.
J Control Release ; 363: 574-584, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37797890

RESUMO

Ischemia/reperfusion (IR) injury is an inevitable pathological event occurring when blood is resupplied to the tissues after a period of ischemia. One of major causes of IR injury is the overproduction of reactive oxygen species (ROS) including hydrogen peroxide (H2O2), which mediates the expression of various inflammatory cytokines to exacerbate tissue damages. The overproduced H2O2 could therefore serve as a diagnostic and therapeutic biomarker of IR injury. In this study, poly(boronated methacrylate) (pBMA) nanoparticles were developed as nanotheranostic agents for renal IR injury, which not only generate CO2 bubbles to enhance the ultrasound contrast but also provide potent preventive effects in a H2O2-triggered manner. The surface of pBMA nanoparticles was decorated with taurodeoxycholic acid (TUDCA) that binds P-selectin overexpressed in inflamed tissues. In the mouse model of renal IR injury, TUDCA-coated pBMA (T-pBMA) nanoparticles preferentially accumulated in the injured kidney and markedly enhanced the ultrasound contrast. T-pBMA nanoparticles also effectively prevented renal IR injury by scavenging H2O2 and suppressing the expression of inflammatory cytokines. Treatment progress of IR injury could be also monitored by echogenic T-pBMA nanoparticles. Given their targeting ability, excellent H2O2-responsiveness, anti-inflammatory activity and H2O2-triggered echogenicity, T-pBMA nanoparticles have excellent translational potential for the management of various H2O2-related diseases including IR injury.


Assuntos
Nanopartículas , Pró-Fármacos , Traumatismo por Reperfusão , Camundongos , Animais , Pró-Fármacos/uso terapêutico , Antioxidantes/uso terapêutico , Peróxido de Hidrogênio/metabolismo , Traumatismo por Reperfusão/diagnóstico por imagem , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Anti-Inflamatórios/uso terapêutico , Polímeros/uso terapêutico , Isquemia/tratamento farmacológico , Meios de Contraste , Citocinas
18.
Biomater Sci ; 11(19): 6600-6610, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37605830

RESUMO

Oxidative stress amplifying compounds could elicit selective killing of cancer cells with minimal toxicity to normal cells and also induce immunogenic cell death (ICD). However, compared to conventional anticancer drugs, oxidative stress amplifying compounds have inferior therapeutic efficacy. It can be postulated that the anticancer therapeutic efficacy and immunostimulating activity of oxidative stress amplifying hybrid prodrug (OSamp) could be fully maximized by employing ultrastable polymeric micelles as drug carriers. In this work, we developed tumour-targeted oxidative stress nanoamplifiers, composed of OSamp, amphiphilic poly(ethylene glycol) methyl ether-block-poly(cyclohexyloxy ethyl glycidyl ether)s (mPEG-PCHGE) and a lipopeptide containing Arg-Gly-Asp (RGD). Tumour targeted OSamp-loaded mPEG-PCHGE (T-POS) micelles exhibited excellent colloidal stability and significant cytotoxicity to cancer cells with the expression of DAMPs (damage-associated molecular patterns). In the syngeneic mouse tumour model, T-POS micelles induced significant apoptotic cell death to inhibit tumour growth without noticeable body weight changes. T-POS micelles also induced ICD and activated adaptive immune responses by increasing the populations of cytotoxic CD4+ and CD8+ T cells. Therefore, these results suggest that T-POS micelles hold great translational potential as immunostimulating anticancer nanomedicine.


Assuntos
Antineoplásicos , Neoplasias , Pró-Fármacos , Camundongos , Animais , Micelas , Linfócitos T CD8-Positivos , Nanomedicina , Polímeros/química , Polietilenoglicóis/química , Antineoplásicos/química , Portadores de Fármacos/química , Pró-Fármacos/farmacologia , Estresse Oxidativo , Neoplasias/tratamento farmacológico , Linhagem Celular Tumoral
19.
iScience ; 26(9): 107511, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37636056

RESUMO

Cell differentiation is associated with global changes in translational activity. Here, we characterize how mRNA poly(A) tail processing supports this dynamic. We observe that decreased translation during neuronal differentiation of P19 cells correlates with the downregulation of 5'-terminal oligopyrimidine (TOP) transcripts which encode the translational machinery. Despite their downregulation, TOP transcripts remain highly stable and show increased translation as cells differentiate. Changes in TOP mRNA metabolism are reflected by their accumulation with poly(A) tails ∼60-nucleotide (nt) long. The dynamic changes in poly(A) processing can be partially recapitulated by depleting LARP1 or activating the mTOR pathway in undifferentiated cells. Although mTOR-induced accumulation of TOP mRNAs with tails ∼60-nt long does not trigger differentiation, it is associated with reduced proliferation of neuronal progenitors. We propose that while TOP mRNAs are transcriptionally silenced, their post-transcriptional regulation mediated by a specific poly(A) processing ensures an adequate supply of ribosomes to complete differentiation.

20.
J Periodontal Implant Sci ; 53(4): 306-317, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37524378

RESUMO

PURPOSE: Biphasic calcium phosphate (BCP), a widely used biomaterial for bone regeneration, contains synthetic hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP), the ratio of which can be adjusted to modulate the rate of degradation. The aim of this study was to evaluate the clinical and radiographic benefits of reconstructing peri-implant bone defects with a newly developed BCP consisting of 40% ß-TCP and 60% HA compared to demineralized bovine bone mineral (DBBM). METHODS: This prospective, multicenter, parallel, single-blind randomized controlled trial was conducted at the periodontology departments of 3 different dental hospitals. Changes in clinical (defect width and height) and radiographic (augmented horizontal bone thickness) parameters were measured between implant surgery with guided bone regeneration (GBR) and re-entry surgery. Postoperative discomfort (severity and duration of pain and swelling) and early soft-tissue wound healing (dehiscence and inflammation) were also assessed. Data were compared between the BCP (test) and DBBM (control) groups using the independent t-test and the χ² test. RESULTS: Of the 53 cases included, 27 were in the test group and 26 were in the control group. After a healing period of 18 weeks, the full and mean resolution of buccal dehiscence defects were 59.3% (n=16) and 71.3% in the test group and 42.3% (n=11) and 57.9% in the control group, respectively. There were no significant differences between the groups in terms of the change in mean horizontal bone augmentation (test group: -0.50±0.66 mm vs. control groups: -0.66±0.83 mm, P=0.133), postoperative discomfort, or early wound healing. No adverse or fatal complications occurred in either group. CONCLUSION: The GBR procedure with the newly developed BCP showed favorable clinical, radiographic, postoperative discomfort-related, and early wound healing outcomes for peri-implant dehiscence defects that were similar to those for DBBM. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0006428.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...