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1.
J Biol Chem ; 300(4): 106794, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38403245

RESUMO

Retinal bipolar and amacrine cells receive visual information from photoreceptors and participate in the first steps of image processing in the retina. Several studies have suggested the operation of aerobic glycolysis and a lactate shuttle system in the retina due to the high production of this metabolite under aerobic conditions. However, whether bipolar cells form part of this metabolic circuit remains unclear. Here, we show that the monocarboxylate transporter 2 is expressed and functional in inner retinal neurons. Additionally, we used genetically encoded FRET nanosensors to demonstrate the ability of inner retinal neurons to consume extracellular lactate as an alternative to glucose. In rod bipolar cells, lactate consumption allowed cells to maintain the homeostasis of ions and electrical responses. We also found that lactate synthesis and transporter inhibition caused functional alterations and an increased rate of cell death. Overall, our data shed light on a notable but still poorly understood aspect of retinal metabolism.


Assuntos
Ácido Láctico , Transportadores de Ácidos Monocarboxílicos , Células Bipolares da Retina , Animais , Camundongos , Metabolismo Energético , Glucose/metabolismo , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Células Bipolares da Retina/metabolismo
2.
J Hepatol ; 80(5): 714-729, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38336348

RESUMO

BACKGROUND & AIMS: Mechanisms behind the impaired response of antigen-specific B cells to therapeutic vaccination in chronic hepatitis B virus (HBV) infection remain unclear. The development of vaccines or strategies to overcome this obstacle is vital for advancing the management of chronic hepatitis B. METHODS: A mouse model, denominated as E6F6-B, was engineered to feature a knock-in of a B-cell receptor (BCR) that specifically recognizes HBsAg. This model served as a valuable tool for investigating the temporal and spatial dynamics of humoral responses following therapeutic vaccination under continuous antigen exposure. Using a suite of immunological techniques, we elucidated the differentiation trajectory of HBsAg-specific B cells post-therapeutic vaccination in HBV carrier mice. RESULTS: Utilizing the E6F6-B transfer model, we observed a marked decline in antibody-secreting cells 2 weeks after vaccination. A dysfunctional and atypical pre-plasma cell population (BLIMP-1+ IRF4+ CD40- CD138- BCMA-) emerged, manifested by sustained BCR signaling. By deploying an antibody to purge persistent HBsAg, we effectively prompted the therapeutic vaccine to provoke conventional plasma cell differentiation. This resulted in an enhanced anti-HBs antibody response and facilitated HBsAg clearance. CONCLUSIONS: Sustained high levels of HBsAg limit the ability of therapeutic hepatitis B vaccines to induce the canonical plasma cell differentiation necessary for anti-HBs antibody production. Employing a strategy combining antibodies with vaccines can surmount this altered humoral response associated with atypical pre-plasma cells, leading to improved therapeutic efficacy in HBV carrier mice. IMPACT AND IMPLICATIONS: Therapeutic vaccines aimed at combatting HBV encounter suboptimal humoral responses in clinical settings, and the mechanisms impeding their effectiveness have remained obscure. Our research, utilizing the innovative E6F6-B mouse transfer model, reveals that the persistence of HBsAg can lead to the emergence of an atypical pre-plasma cell population, which proves to be relevant to the potency of therapeutic HBV vaccines. Targeting the aberrant differentiation process of these atypical pre-plasma cells stands out as a critical strategy to amplify the humoral response elicited by HBV therapeutic vaccines in carrier mouse models. This discovery suggests a compelling avenue for further study in the context of human chronic hepatitis B. Encouragingly, our findings indicate that synergistic therapy combining HBV-specific antibodies with vaccines offers a promising approach that could significantly advance the pursuit of a functional cure for HBV.


Assuntos
Hepatite B Crônica , Hepatite B , Camundongos , Humanos , Animais , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B , Vacinas contra Hepatite B/uso terapêutico , Anticorpos Anti-Hepatite B , Diferenciação Celular , Hepatite B/prevenção & controle , Hepatite B/tratamento farmacológico
3.
Antimicrob Agents Chemother ; 68(5): e0115923, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38506549

RESUMO

Vancomycin heteroresistance is prone to missed detection and poses a risk of clinical treatment failure. We encountered one clinical Enterococcus faecium strain, SRR12, that carried a complete vanM gene cluster but was determined as susceptible to vancomycin using the broth microdilution method. However, distinct subcolonies appeared within the clear zone of inhibition in the E-test assay, one of which, named SRR12-v1, showed high-level resistance to vancomycin. SRR12 was confirmed as heteroresistant to vancomycin using population analysis profiling and displayed "revive" growth curves with a lengthy lag phase of over 13 hours when exposed to 2-32 mg/L vancomycin. The resistant subcolony SRR12-v1 was found to carry an identical vanM gene cluster to that of SRR12 but a significantly increased vanM copy number in the genome. Long-read whole genome sequencing revealed that a one-copy vanM gene cluster was located on a pELF1-like linear plasmid in SRR12. In comparison, tandem amplification of the vanM gene cluster jointed with IS1216E was seated on a linear plasmid in the genome of SRR12-v1. These amplifications of the vanM gene cluster were demonstrated as unstable and would decrease accompanied by fitness reversion after serial passaging for 50 generations under increasing vancomycin pressure or without antibiotic pressure but were relatively stable under constant vancomycin pressure. Further, vanM resistance in resistant variants was verified to be carried by conjugative plasmids with variable sizes using conjugation assays and S1-pulsed field gel electrophoresis blotting, suggesting the instability/flexibility of vanM cluster amplification in the genome and an increased risk of vanM resistance dissemination.


Assuntos
Antibacterianos , Enterococcus faecium , Testes de Sensibilidade Microbiana , Família Multigênica , Plasmídeos , Resistência a Vancomicina , Vancomicina , Enterococcus faecium/genética , Enterococcus faecium/efeitos dos fármacos , Plasmídeos/genética , Vancomicina/farmacologia , Resistência a Vancomicina/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Humanos , Sequenciamento Completo do Genoma
4.
Alzheimers Dement ; 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39410879

RESUMO

INTRODUCTION: Oculomotor and gait dysfunctions are closely associated with cognition. However, oculo-gait patterns and their correlation with cognition in cerebral small vessel disease (CSVD) remain unclear. METHODS: Patients with CSVD from a hospital-based cohort (n = 194) and individuals with presumed early CSVD from a community-based cohort (n = 319) were included. Oculo-gait patterns were measured using the artificial intelligence (AI) -assisted 'EyeKnow' eye-tracking and 'ReadyGo' motor evaluation systems. Multivariable linear and logistic regression models were employed to investigate the association between the oculo-gait parameters and cognition. RESULTS: Anti-saccade accuracy, stride velocity, and swing velocity were significantly associated with cognition in both patients and community dwellers with CSVD, and could identify cognitive impairment in CSVD with moderate accuracy (area under the curve [AUC]: hospital cohort, 0.787; community cohort, 0.810) after adjusting for age and education. DISCUSSION: The evaluation of oculo-gait features (anti-saccade accuracy, stride velocity, and swing velocity) may help screen cognitive impairment in CSVD. HIGHLIGHTS: Oculo-gait features (lower anti-saccade accuracy, stride velocity, and swing velocity) were associated with cognitive impairment in cerebral small vessel disease (CSVD). Logistic model integrating the oculo-gait features, age, and education level moderately distinguished cognitive status in CSVD. Artificial intelligence-assisted oculomotor and gait measurements provide quick and accurate evaluation in hospital and community settings.

5.
Actas Esp Psiquiatr ; 52(3): 334-346, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38863057

RESUMO

BACKGROUND: The use of antidepressants, especially selective serotonin reuptake inhibitors (SSRIs), has been linked to adverse effects on bone health, but findings are conflicting. This study aimed to quantify the associations between newer antidepressants and bone mineral density (BMD) and fracture risk through a comprehensive meta-analysis. METHODS: Observational studies on the association between the use of novel antidepressants and BMD and hip fracture were systematically searched in PubMed, Embase, CINAHL, Cochrane Library, and Scopus. Random effects meta-analyses were conducted to pool results across the eligible studies. The heterogeneity, publication bias, and influence were assessed extensively. RESULTS: 14 eligible studies with 1,417,134 participants were identified. Antidepressant use was associated with significantly lower BMD compared to non-use at all skeletal sites examined, with pooled standardized mean differences (SMD) ranging from -0.02 (total hip) to -0.04 (femoral neck). Importantly, antidepressant use was associated with a 2.5-fold increased risk of hip fracture (pooled odds ratio (OR) 2.50, 95% CI 2.26-2.76). While heterogeneity was detected, the overall findings were robust in sensitivity analyses. CONCLUSIONS: This meta-analysis provided strong evidence that novel antidepressants, especially widely used SSRIs, have detrimental impacts on bone health. The observed associations with decreased BMD and doubled hip fracture risk have important clinical implications.


Assuntos
Antidepressivos , Densidade Óssea , Fraturas do Quadril , Osteoporose , Humanos , Densidade Óssea/efeitos dos fármacos , Antidepressivos/efeitos adversos , Osteoporose/induzido quimicamente , Osteoporose/tratamento farmacológico , Fraturas do Quadril/induzido quimicamente , Fraturas do Quadril/epidemiologia , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Fraturas por Osteoporose/induzido quimicamente , Fraturas por Osteoporose/epidemiologia , Fatores de Risco
6.
Antimicrob Agents Chemother ; 67(11): e0056323, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37902403

RESUMO

Daptomycin (DAP) is effective against methicillin-resistant Staphylococcus aureus (MRSA). However, reduced susceptibility to DAP in MRSA may lead to treatment failures. We aim to determine the distribution of DAP minimum inhibitory concentrations (MICs) and DAP heteroresistance (hDAP) among MRSA lineages in China. A total of 472 clinical MRSA isolates collected from 2015 to 2017 in China were examined for DAP susceptibility. All isolates (n = 472) were found to be DAP susceptible, but 35.17% (166/472) of them exhibited a high DAP MIC (MIC >0.5 µg/mL). The high DAP MIC group contained a larger proportion of isolates with a higher vancomycin or teicoplanin MIC (>1.5 µg/mL) than the low DAP MIC group (19.3% vs 7.8%, P < 0.001; 22.3% vs 8.2%, P < 0.001). We compared the clonal complex (CC) distributions and clinical characteristics in MRSA isolates stratified by DAP MIC. CC5 isolates were less susceptible to DAP (MIC50 = 1 µg/mL) than CC59 isolates (MIC50 = 0.5 µg/mL, P < 0.001). Population analysis profiling revealed that 5 of 10 ST5 and ST59 DAP-susceptible MRSA isolates investigated exhibited hDAP. The results also showed that CC5 MRSA with an agrA mutation (I238K) had a higher DAP MIC than those with a wild-type agrA (P < 0.001). The agrA-I238K mutation was found to be associated with agr dysfunction as indicated by the loss of δ-hemolysin production. In addition, agr/psmα defectiveness was associated with hDAP in MRSA. Whole-genome sequencing analysis revealed mutations in mprF and walR/walK in DAP-resistant subpopulations, and most DAP-resistant subpopulations (6/8, 75%) were stable. Our study suggests that the increased DAP resistance and hDAP in MRSA may threaten the effectiveness against MRSA infections.


Assuntos
Daptomicina , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Daptomicina/farmacologia , Daptomicina/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Vancomicina/farmacologia , Testes de Sensibilidade Microbiana
7.
J Antimicrob Chemother ; 78(8): 1871-1881, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37287125

RESUMO

BACKGROUND: The overuse of antibiotics in livestock is contributing to the burden of antimicrobial resistance in humans, representing a One Health challenge. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has recently become a growing concern, and ST9 is the major LA-MRSA lineage in China and has emerged in clinical settings. METHODS: Antimicrobial susceptibility testing was used to evaluate the tetracycline resistance of ST9 MRSA collections, and gene cloning experiments were performed to explore the resistance mechanisms. Whole-genome sequencing and comparative genomics were used to analyse the genetic features of clinical ST9 isolates. A phylogenetic tree was constructed to investigate the relationship of human- and livestock-derived ST9 isolates. RESULTS: Clinical ST9 isolates were found to possess several types of resistance genes and resistance-related mutations and were multidrug-resistant. Notably, all clinical ST9 isolates were resistant to third-generation tetracyclines. Cloning experiments showed that both the acquisition of the tetracycline resistance gene tet(L)/tet(63) and a mutation in the rpsJ gene contributed to third-generation tetracycline resistance. Phylogenetic analysis showed that the ST9 isolates collected in healthcare systems were probably transmitted from livestock. The ST9 lineage underwent multiple interspecies recombination events and gained many resistance elements. Furthermore, the resistance to third-generation tetracyclines may have evolved under tetracycline pressure in livestock. CONCLUSIONS: The evolution of ST9 MRSA in livestock and transmission of this clone between humans and livestock highlight the importance of establishing control strategies with the One Health approach to reduce the burden of antibiotic resistance.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Humanos , Gado , Resistência a Tetraciclina/genética , Filogenia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/veterinária , Antibacterianos/farmacologia , Tetraciclina , China/epidemiologia
8.
Exp Eye Res ; 226: 109352, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36528083

RESUMO

Müller cells, the glial cells of the retina, provide metabolic support for photoreceptors and inner retinal neurons, and have been proposed as source of the significant lactate production of this tissue. To better understand the role of lactate in retinal metabolism, we expressed a lactate and a glucose nanosensor in organotypic mouse retinal explants cultured for 14 days, and used FRET imaging in acute vibratome sections of the explants to study metabolite flux in real time. Pharmacological manipulation with specific monocarboxylate transporter (MCT) inhibitors and immunohistochemistry revealed the functional expression of MCT1, MCT2 and MCT4 in Müller cells of retinal explants. The introduction of FRET nanosensors to measure key metabolites at the cellular level may contribute to a better understanding of heretofore poorly understood issues in retinal metabolism.


Assuntos
Células Ependimogliais , Transferência Ressonante de Energia de Fluorescência , Camundongos , Animais , Células Ependimogliais/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Retina/metabolismo , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo
9.
Neuroepidemiology ; 57(6): 413-422, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37734325

RESUMO

INTRODUCTION: Cerebral small vessel disease (CSVD) is a significant burden of morbidity and mortality among elderly people around the world. Epidemiological data with complete CSVD evaluations and a large sample size in the general population are still limited. METHODS: Community-dwelling residents in Lishui city in China from the cross-sectional survey of the Polyvascular Evaluation for Cognitive Impairment and Vascular Events (PRECISE) study were included in this study from 2017 to 2019. All participants underwent 3 Tesla brain magnetic resonance images to assess CSVD imaging markers. Demographic and risk factor data were collected. The general and age-specific prevalence of lacune, confluent white matter hyperintensity (WMH), moderate-severe enlarged perivascular spaces (EPVS), cerebral microbleed (CMB), and total CSVD score (an ordinal scale from 0 to 4, counting the presence of four imaging markers of CSVD) was evaluated. Associations between vascular risk factors and these markers were analyzed by multivariable logistic regression. RESULTS: A total of 3,063 participants were enrolled. The mean age was 61.2 years and 46.5% were men. The most prevalent CSVD marker was confluent WMH (16.7%), followed by CMB (10.2%), moderate-severe EPVS in the basal ganglia (BG-EPVS) (9.8%), and lacune (5.6%). 30.5% of the participants have at least one of the four markers (total CSVD score ≥1 points). The prevalence of CSVD markers increases as age increases. Age and hypertension were independent risk factors for four CSVD markers and the total CSVD score. CONCLUSIONS: In this Chinese cohort with community-based adults aged 50-75 years, our findings showed a prevalence of 30.5% for CSVD. The most prevalent CSVD marker was confluent WMH, followed by CMB, moderate-severe BG-EPVS, and lacune. The risk factors for CSVD must be strictly screened and controlled in adults living in the community.


Assuntos
Doenças de Pequenos Vasos Cerebrais , Masculino , Idoso , Adulto , Humanos , Pessoa de Meia-Idade , Feminino , Prevalência , Estudos Transversais , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/epidemiologia , Encéfalo , Imageamento por Ressonância Magnética , Fatores de Risco
10.
Anal Bioanal Chem ; 415(20): 4935-4947, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37452213

RESUMO

Due to universal contamination and synergistic toxicity of multiple mycotoxins in foodstuff, reliable and high-throughput detection methods for multiple mycotoxins are urgently needed in corn products. In this study, a novel dual-channel immunochromatographic assay (ICA) based on improved up-conversion nanoparticles (IUCNPs) was developed for rapidly detecting aflatoxin B1 (AFB1) and zearalenone (ZEN). The synthesized IUCNPs doped by 30% Lu3+ showed a larger size, more regular structure, and brighter fluorescence intensity than conventional UCNPs. The limits of detection (LODs) of single-channel ICA test strips for AFB1 and ZEN detection were 0.01 and 0.1 ng/mL, respectively. After the optimization, the dual-channel ICA of AFB1 and ZEN in 10 min was conducted, resulting in low detection limits of 0.025 and 0.1 ng/mL, respectively. Moreover, the built assay was revealed to be highly specific for six other food-contaminated mycotoxins, and exhibited excellent accuracy, with corresponding R2 of 0.9931 and 0.9982 in calibration curves, respectively. Long-term storage experiments indicated that the dual-channel test strips had superior stability and precision. The LODs of AFB1 and ZEN in spiked maize were 0.025 and 0.25 µg/kg, demonstrating great sensitivity and matrix tolerance. Furthermore, the IUNCP-ICA was validated by high-performance liquid chromatography (HPLC) analyses, and a satisfactory consistency was obtained in 15 natural maize samples. Thus, the IUCNPs-ICA proposed in this work realized rapid and sensitive detection of AFB1 and ZEN, providing broad application potential in on-site screening for multiple mycotoxins in agricultural products.


Assuntos
Micotoxinas , Nanopartículas , Zearalenona , Zearalenona/análise , Aflatoxina B1/análise , Zea mays/química , Contaminação de Alimentos/análise , Limite de Detecção , Micotoxinas/análise
11.
Adv Exp Med Biol ; 1415: 429-434, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37440068

RESUMO

The retina has the highest energy consumption of any tissue in the human body. Remarkably, to satisfy its energy demand, the retina appears to rely mostly on aerobic glycolysis, which results in the production and release of large amounts of lactate. In the present study, we compared two different methods to assess lactate release from in vitro organotypic retinal explants cultured under entirely controlled, serum-free conditions. We used a standard lactate assay kit and 1H-nuclear magnetic resonance (NMR) spectroscopy-based analysis. We found that during the culturing of retinal explants derived from wild-type mice, lactate was released in large amounts and that the two different methods agreed well with each other. When comparing wild-type retina with degenerating rd1 mouse retina, we found the latter to release significantly higher amounts of lactate. Hence, degenerating retina may have an even higher energy demand and metabolic rate compared to healthy retina. We conclude that the use of lactate measurement can be a reliable and simple readout to evaluate ongoing retinal metabolism.


Assuntos
Ácido Láctico , Degeneração Retiniana , Humanos , Camundongos , Animais , Ácido Láctico/metabolismo , Retina/metabolismo , Degeneração Retiniana/metabolismo
12.
Proc Natl Acad Sci U S A ; 117(22): 12315-12323, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32424106

RESUMO

The androgen receptor (AR) antagonist enzalutamide is one of the principal treatments for men with castration-resistant prostate cancer (CRPC). However, not all patients respond, and resistance mechanisms are largely unknown. We hypothesized that genomic and transcriptional features from metastatic CRPC biopsies prior to treatment would be predictive of de novo treatment resistance. To this end, we conducted a phase II trial of enzalutamide treatment (160 mg/d) in 36 men with metastatic CRPC. Thirty-four patients were evaluable for the primary end point of a prostate-specific antigen (PSA)50 response (PSA decline ≥50% at 12 wk vs. baseline). Nine patients were classified as nonresponders (PSA decline <50%), and 25 patients were classified as responders (PSA decline ≥50%). Failure to achieve a PSA50 was associated with shorter progression-free survival, time on treatment, and overall survival, demonstrating PSA50's utility. Targeted DNA-sequencing was performed on 26 of 36 biopsies, and RNA-sequencing was performed on 25 of 36 biopsies that contained sufficient material. Using computational methods, we measured AR transcriptional function and performed gene set enrichment analysis (GSEA) to identify pathways whose activity state correlated with de novo resistance. TP53 gene alterations were more common in nonresponders, although this did not reach statistical significance (P = 0.055). AR gene alterations and AR expression were similar between groups. Importantly, however, transcriptional measurements demonstrated that specific gene sets-including those linked to low AR transcriptional activity and a stemness program-were activated in nonresponders. Our results suggest that patients whose tumors harbor this program should be considered for clinical trials testing rational agents to overcome de novo enzalutamide resistance.


Assuntos
Antineoplásicos/administração & dosagem , Resistencia a Medicamentos Antineoplásicos , Feniltioidantoína/análogos & derivados , Neoplasias de Próstata Resistentes à Castração/genética , Receptores Androgênicos/administração & dosagem , Receptores Androgênicos/genética , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas , Feniltioidantoína/administração & dosagem , Antígeno Prostático Específico/metabolismo , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismo
13.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(2): 207-210, 2023 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-37096478

RESUMO

OBJECTIVE: To analyze the key points of evaluation on the safety and effectiveness of wearable rehabilitation walking aid robot, then improve its quality control ability. METHODS: Combined with the functional and structural characteristics of the wearable rehabilitation walking aid robot, the key points of quality evaluation were analyzed from the aspects of electrical safety and main performance. Some reasonable suggestions were put forward for the design and development of the robot. RESULTS: The key points of safety and effectiveness evaluation of wearable rehabilitation aid walking robot focused on battery, protection device, operation parameters, static load strength, network security, environmental adaptability and other aspects. CONCLUSIONS: By analyzing the key points of safety and effectiveness evaluation of wearable rehabilitation walking aid robot, certain ideas are provided for the design and development of such products, and reference is provided for the improvement of product quality evaluation system.


Assuntos
Medicina , Robótica , Dispositivos Eletrônicos Vestíveis , Caminhada , Equipamentos de Proteção
14.
J Neurochem ; 160(2): 283-296, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34726780

RESUMO

The retina has the highest relative energy consumption of any tissue, depending on a steady supply of glucose from the bloodstream. Glucose uptake is mediated by specific transporters whose regulation and expression are critical for the pathogenesis of many diseases, including diabetes and diabetic retinopathy. Here, we used immunofluorescence to show that glucose transporter-2 (GLUT2) is expressed in horizontal cells of the mouse neuroretina in proximity to inner retinal capillaries. To study the function of GLUT2 in the murine retina, we used organotypic retinal explants, cultivated under entirely controlled, serum-free conditions and exposed them to streptozotocin, a cytotoxic drug transported exclusively by GLUT2. Contrary to our expectations, streptozotocin did not measurably affect horizontal cell viability, while it ablated rod and cone photoreceptors in a concentration-dependent manner. Staining for poly-ADP-ribose (PAR) indicated that the detrimental effect of streptozotocin on photoreceptors may be associated with DNA damage. The negative effect of streptozotocin on the viability of rod photoreceptors was counteracted by co-administration of either the inhibitor of connexin-formed hemi-channels meclofenamic acid or the blocker of clathrin-mediated endocytosis dynasore. Remarkably, cone photoreceptors were not protected from streptozotocin-induced degeneration by neither of the two drugs. Overall, these data suggest the existence of a GLUT2-dependent glucose transport shuttle, from horizontal cells into photoreceptor synapses. Moreover, our study points at different glucose uptake mechanisms in rod and cone photoreceptors.


Assuntos
Transportador de Glucose Tipo 2/metabolismo , Glucose/metabolismo , Células Fotorreceptoras/metabolismo , Células Horizontais da Retina/metabolismo , Sinapses/metabolismo , Animais , Transporte Biológico , Camundongos , Retina/metabolismo
15.
Mutagenesis ; 37(3-4): 213-225, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-35869703

RESUMO

Two prototypical genotoxicants, benzo[a]pyrene (B[a]P) and colchicine (COL), were selected as model compounds to deduce their quantitative genotoxic dose-response relationship at low doses in a multi-endpoint genotoxicity assessment platform. Male Sprague-Dawley rats were treated with B[a]P (2.5-80 mg/kg bw/day) and COL (0.125-2 mg/kg bw/day) daily for 28 days. The parameters included were as follows: comet assay in the peripheral blood and liver, Pig-a gene mutation assay in the peripheral blood, and micronucleus test in the peripheral blood and bone marrow. A significant increase was observed in Pig-a mutant frequency in peripheral blood for B[a]P (started at 40 mg/kg bw/day on Day 14, started at 20 mg/kg bw/day on Day 28), whereas no statistical difference for COL was observed. Micronucleus frequency in reticulocytes of the peripheral blood and bone marrow increased significantly for B[a]P (80 mg/kg bw/day on Day 4, started at 20 mg/kg bw/day on Days 14 and 28 in the blood; started at 20 mg/kg bw/day on Day 28 in the bone marrow) and COL (started at 2 mg/kg bw/day on Day 14, 1 mg/kg bw/day on Day 28 in the blood; started at 1 mg/kg bw/day on Day 28 in the bone marrow). No statistical variation was found in indexes of comet assay at all time points for B[a]P and COL in the peripheral blood and liver. The dose-response relationships of Pig-a and micronucleus test data were analyzed for possible point of departures using three quantitative approaches, i.e., the benchmark dose, breakpoint dose, and no observed genotoxic effect level. The practical thresholds of the genotoxicity of B[a]P and COL estimated in this study were 0.122 and 0.0431 mg/kg bw/day, respectively, and our results also provided distinct genotoxic mode of action of the two chemicals.


Assuntos
Benzo(a)pireno , Colchicina , Ratos , Animais , Masculino , Benzo(a)pireno/toxicidade , Colchicina/toxicidade , Ratos Sprague-Dawley , Eritrócitos , Testes para Micronúcleos/métodos , Ensaio Cometa/métodos , Reticulócitos , Dano ao DNA , Relação Dose-Resposta a Droga , Testes de Mutagenicidade/métodos
16.
Langmuir ; 38(15): 4578-4588, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35380840

RESUMO

Polyetherketoneketone (PEKK) is considered to be a potential substitute material for metal bone implants because of its advantageous biocompatibility, chemical stability, and mechanical properties, but clinical application has been severely restricted due to PEKK's lack of antibacterial ability and biological activity. In this study, LL-37, a natural human antimicrobial peptide, was successfully modified on the PEKK surface with polydopamine as the intermediate layer and released continuously for more than 6 days. The results of the MTT assay, colony counts, and Live/Dead staining demonstrated that compared to unmodified PEKK, the LL-37-modified PEKK significantly inhibited the adhesion, vitality, and bacterial biofilm growth of Staphylococcus aureus and Escherichia coli in a concentration-dependent way. Furthermore, the LL-37-modified PEKK enhanced biocompatibility (cell adhesion and viability) and promoted osteogenic differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells. Our data suggested that LL-37-modified PEKK might be a promising material for use in orthopedic implants.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Antibacterianos/farmacologia , Benzofenonas/química , Diferenciação Celular , Humanos , Polímeros
17.
J Org Chem ; 87(11): 7013-7021, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35603573

RESUMO

Electrocatalytic three-component acylcyanation and aminocyanation of simple alkenes have been developed. The protocol features high functional group tolerance and can easily be scaled up. The key to success is to use an electrophilic cyanation source, enabling a broadened use of alkenes to aliphatic ones for acylcyanation.


Assuntos
Alcenos , Catálise
18.
BMC Geriatr ; 22(1): 635, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35918645

RESUMO

BACKGROUND: Good self-management behaviors in patients with knee osteoarthritis can improve disease awareness, treatment effectiveness, quality of life, and reduce medical costs. However, there is a paucity of studies focusing on patients with knee osteoarthritis. Therefore, the purpose of this study was to explore the mediating effect of self-efficacy on aspects of social support and self-management behaviors in this population. METHODS: This study employed a cross-sectional design and convenience sampling to survey patients with knee osteoarthritis in an outpatient department of a regional hospital in northern Taiwan from February 22, 2021, to April 15, 2021. The inclusion criteria for patients were (1) those diagnosed by a physician with knee osteoarthritis and (2) who could communicate in Chinese or Taiwanese. Participants were asked to complete a demographic questionnaire, the Arthritis Self-Efficacy Scale (ASE), the Inventory of Socially Supportive Behavior (including enacted support and perceived social support), and the Arthritis Self-Management Assessment Tool (ASMAT). In addition, the Kellgren-Lawrence Grading Scale was obtained from a chart review. Data were analyzed with descriptive statistics, t-test, one-way analysis of variance, Pearson product-moment correlation, and mediation analysis. RESULTS: A total of 140 patients met the inclusion criteria. The mean age of participants was 70.21 ± 10.84years; most (73.6%) were female. The mean total score of the ASMAT was 64.27 ± 14.84. Scores for the ASE, enacted support, and perceived social support were significantly positively correlated with ASMAT (all p < .001). The standardized coefficient for total effect and direct effect of perceived social support on ASMAT was 0.899 (p < .001) and 0.754 (p < .05), respectively. After introducing the ASE into the model, the indirect effect was 0.145 (p < .05), which indicated that ASE had a partial mediating effect on the relationship between perceived social support and ASMAT. CONCLUSION: Our findings might suggest that perceived social support indirectly affected ASMAT through ASE. Therefore, interventions designed to increase self-efficacy and social support could enhance self-management behaviors for patients with knee osteoarthritis.


Assuntos
Osteoartrite do Joelho , Autogestão , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Osteoartrite do Joelho/diagnóstico , Osteoartrite do Joelho/terapia , Qualidade de Vida , Autoeficácia , Apoio Social
19.
J Appl Toxicol ; 42(8): 1310-1322, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35128692

RESUMO

The mycotoxin altertoxin I (ATX-I) is one of secondary metabolites produced by Alternaria fungi and is frequently detected as food and feed contaminants. Little is known about the genotoxicity of the ATX-I. In order to evaluate potential genotoxicity and general toxicity of ATX-I, the novel 28-day multiendpoint (Pig-a assay + micronucleus [MN] test + comet assay) genotoxicity platform was applied. Male Sprague-Dawley (SD) rats were randomized to five groups (six rats per group), that is, a positive control group (N-ethyl-N-nitrosourea [ENU], 40 mg/kg.bw/d), two solvent control groups (PBS and corn oil), and two ATX-I-treated groups (low-dose group [1.10 µg/kg.bw/d] and high-dose group [5.51 µg/kg.bw/d]). Treatments were administered by oral gavage to male SD rats for 28 consecutive days. Histopathological damages in the liver, kidney, and spleen were observed, but without significant changes in hematological and serum biochemical parameters. Genotoxic endpoints indicated that ATX-I could cause DNA damage. To summarize, in a relatively low-dose range, ATX-I may not have direct genotoxicity in vivo but could induce liver, kidney, and spleen damage.


Assuntos
Micotoxinas , Perileno , Animais , Ensaio Cometa , Dano ao DNA , Masculino , Testes para Micronúcleos , Perileno/análogos & derivados , Perileno/toxicidade , Ratos , Ratos Sprague-Dawley
20.
BMC Musculoskelet Disord ; 23(1): 187, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35227229

RESUMO

BACKGROUND: Kinesio Taping (KT) is proved useful to many musculoskeletal disorders. But the mechanism remains unclear. The kinesio tape works by sticking to the skin surface. So exploring the interaction between the tape and the skin and analyzing its biomechanical influence may be an effective way to explore the mechanism of the tape. OBJECTIVES: This study aimed to investigate the effect of Kinesio taping and taping methods on skin deformation during knee joint flexion and extension motion and further explore its possible functional mechanisms. METHODS: Ten healthy and pain-free subjects (4 males, 6 females) were recruited in this study. The skin observation area on the anterior side of the right thigh of the subjects was divided into 11 segments by 12 reflective marker points for distance measurement, from the distal knee to the proximal knee, the length of the interval was L1 to L11, and the total length was L0. Subjects were treated with no KT (NT), resting positive taping (RPT), resting negative taping (RNT), stretching positive taping (SPT), and stretching negative taping (SNT). A Qualisys infrared high-speed three-dimensional spatial coordinate capture system was used to observe changes in the length of the observed skin surface on the right anterior thigh during right knee flexion and extension in the sitting position. RESULTS: During right knee flexion and extension in the seated position in 10 subjects, all skin segment deformations produced significant differences between intervention groups (P < 0.05), except for L1 during flexion (P = 0.07). During right knee flexion and extension, total length, L0, and spacing lengths, L1, L6, and L11, were longer in the NT group than in all other groups. L0 and L1 were both longer in the stretched position than in the rest position; L11 also showed this trend. CONCLUSIONS: The usage of the KT had an effect on the biomechanical changes of the skin, resulting in changes in skin deformation. I-tape, natural tension taping can shorten the skin distance between the two ends of the tape. Limb position during taping may influence the KT's effects. However, the change in taping direction showed no significant effects on skin deformation during exercise. KT may apply a pre-stress in the biomechanics of the skin.


Assuntos
Fita Atlética , Fenômenos Biomecânicos , Feminino , Humanos , Articulação do Joelho , Perna (Membro) , Masculino , Amplitude de Movimento Articular
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