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1.
J Exp Clin Cancer Res ; 43(1): 108, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38600610

RESUMEN

Ferroptosis is a newly identified iron-dependent form of death that is becoming increasingly recognized as a promising avenue for cancer therapy. N6-methyladenosine (m6A) is the most abundant reversible methylation modification in mRNA contributing to tumorigenesis. However, the crucial role of m6A modification in regulating ferroptosis during colorectal cancer (CRC) tumorigenesis remains elusive. Herein, we find that m6A modification is increased during ferroptotic cell death and correlates with the decreased m6A demethylase fat mass and obesity-associated protein (FTO) expression. Functionally, we demonstrate that suppressing FTO significantly induces CRC ferroptotic cell death, as well as enhancing CRC cell sensitivity to ferroptosis inducer (Erastin and RSL3) treatment. Mechanistically, high FTO expression increased solute carrier family 7 member 11 (SLC7A11) or glutathione peroxidase 4 (GPX4) expressions in an m6A-YTHDF2 dependent manner, thereby counteracting ferroptotic cell death stress. In addition, we identify Mupirocin as a novel inhibitor of FTO, and Mupirocin induces CRC ferroptosis and inhibits tumor growth. Clinically, the levels of FTO, SLC7A11, and GPX4, are highly correlated expression in CRC tissues. Our findings reveal that FTO protects CRC from ferroptotic cell death in promoting CRC tumorigenesis through triggering SLC7A11/GPX4 expression.


Asunto(s)
Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Neoplasias Colorrectales , Mupirocina , Humanos , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/antagonistas & inhibidores , Sistema de Transporte de Aminoácidos y+ , Carcinogénesis , Muerte Celular , Transformación Celular Neoplásica , Neoplasias Colorrectales/tratamiento farmacológico
2.
J Am Chem Soc ; 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38663863

RESUMEN

Herein, we present the discovery and development of the first photoredox-catalyzed alkoxy diazomethylation of alkenes with hypervalent iodine reagents and alcohols. This multicomponent process represents a new disconnection approach to diazo compounds and is featured by a broad scope, mild reaction conditions, and excellent selectivity. Key to the process was the generation of diazomethyl radicals, which engaged alkenes and alcohols in an inter- and intramolecular fashion by a photoredox-catalyzed oxidative radical-polar crossover leading to unexplored ß-alkoxydiazo compounds. The synthetic utility of such diazo compounds was demonstrated with a series of transformations involving C-H, N-H, and O-H insertions as well as in the construction of complex sp3-rich heterocycles.

3.
iScience ; 27(5): 109665, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38646167

RESUMEN

Glucagon is secreted by pancreatic α-cells to counteract hypoglycaemia. How glucose regulates glucagon secretion remains unclear. Here, using mouse islets, we studied the role of transmembrane and endoplasmic reticulum (ER) Ca2+ on intrinsic α-cell glucagon secretion. Blocking isradipine-sensitive L-type voltage-gated Ca2+ (Cav) channels abolished α-cell electrical activity but had little impact on its cytosolic Ca2+ oscillations or low-glucose-stimulated glucagon secretion. In contrast, depleting ER Ca2+ with cyclopiazonic acid or blocking ER Ca2+-releasing ryanodine receptors abolished α-cell glucose sensitivity and low-glucose-stimulated glucagon secretion. ER Ca2+ mobilization in α-cells is regulated by intracellular ATP and likely to be coupled to Ca2+ influx through P/Q-type Cav channels. ω-Agatoxin IVA blocked α-cell ER Ca2+ release and cell exocytosis, but had no additive effect on glucagon secretion when combined with ryanodine. We conclude that glucose regulates glucagon secretion through the control of ER Ca2+ mobilization, a mechanism that can be independent of α-cell electrical activity.

4.
ACS Nano ; 2024 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-38644575

RESUMEN

Bimetallic alloy nanoparticles have garnered substantial attention for diverse catalytic applications owing to their abundant active sites and tunable electronic structures, whereas the synthesis of ultrafine alloy nanoparticles with atomic-level homogeneity for bulk-state immiscible couples remains a formidable challenge. Herein, we present the synthesis of RuxCo1-x solid-solution alloy nanoparticles (ca. 2 nm) across the entire composition range, for highly efficient, durable, and selective CO2 hydrogenation to CH4 under mild conditions. Notably, Ru0.88Co0.12/TiO2 and Ru0.74Co0.26/TiO2 catalysts, with 12 and 26 atom % of Ru being substituted by Co, exhibit enhanced catalytic activity compared with the monometallic Ru/TiO2 counterparts both in dark and under light irradiation. The comprehensive experimental investigations and density functional theory calculations unveil that the electronic state of Ru is subtly modulated owing to the intimate interaction between Ru and Co in the alloy nanoparticles, and this effect results in the decline in the CO2 conversion energy barrier, thus ultimately culminating in an elevated catalytic performance relative to monometallic Ru and Co catalysts. In the photopromoted thermocatalytic process, the photoinduced charge carriers and localized photothermal effect play a pivotal role in facilitating the chemical reaction process, which accounts for the further boosted CO2 methanation performance.

5.
Sci Total Environ ; : 172466, 2024 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-38626826

RESUMEN

The burgeoning issue of plasmid-mediated resistance genes (ARGs) dissemination poses a significant threat to environmental integrity. However, the prediction of ARGs prevalence is overlooked, especially for emerging ARGs that are potentially evolving gene exchange hotspot. Here, we explored to classify plasmid or chromosome sequences and detect resistance gene prevalence by using DNABERT. Initially, the DNABERT fine-tuned in plasmid and chromosome sequences followed by multilayer perceptron (MLP) classifier could achieve 0.764 AUC (Area under curve) on external datasets across 23 genera, outperforming 0.02 AUC than traditional statistic-based model. Furthermore, Escherichia, Pseudomonas single genera based model were also be trained to explore its predict performance to ARGs prevalence detection. By integrating K-mer frequency attributes, our model could boost the performance to predict the prevalence of ARGs in an external dataset in Escherichia with 0.0281-0.0615 AUC and Pseudomonas with 0.0196-0.0928 AUC. Finally, we established a random forest model aimed at forecasting the relative conjugation transfer rate of plasmids with 0.7956 AUC, drawing on data from existing literature. It identifies the plasmid's repression status, cellular density, and temperature as the most important factors influencing transfer frequency. With these two models combined, they provide useful reference for quick and low-cost integrated evaluation of resistance gene transfer, accelerating the process of computer-assisted quantitative risk assessment of ARGs transfer in environmental field.

6.
J Neuroinflammation ; 21(1): 106, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38658922

RESUMEN

BACKGROUND: Intracerebral hemorrhage (ICH) is a devastating neurological disease causing severe sensorimotor dysfunction and cognitive decline, yet there is no effective treatment strategy to alleviate outcomes of these patients. The Mas axis-mediated neuroprotection is involved in the pathology of various neurological diseases, however, the role of the Mas receptor in the setting of ICH remains to be elucidated. METHODS: C57BL/6 mice were used to establish the ICH model by injection of collagenase into mice striatum. The Mas receptor agonist AVE0991 was administered intranasally (0.9 mg/kg) after ICH. Using a combination of behavioral tests, Western blots, immunofluorescence staining, hematoma volume, brain edema, quantitative-PCR, TUNEL staining, Fluoro-Jade C staining, Nissl staining, and pharmacological methods, we examined the impact of intranasal application of AVE0991 on hematoma absorption and neurological outcomes following ICH and investigated the underlying mechanism. RESULTS: Mas receptor was found to be significantly expressed in activated microglia/macrophages, and the peak expression of Mas receptor in microglia/macrophages was observed at approximately 3-5 days, followed by a subsequent decline. Activation of Mas by AVE0991 post-treatment promoted hematoma absorption, reduced brain edema, and improved both short- and long-term neurological functions in ICH mice. Moreover, AVE0991 treatment effectively attenuated neuronal apoptosis, inhibited neutrophil infiltration, and reduced the release of inflammatory cytokines in perihematomal areas after ICH. Mechanistically, AVE0991 post-treatment significantly promoted the transformation of microglia/macrophages towards an anti-inflammatory, phagocytic, and reparative phenotype, and this functional phenotypic transition of microglia/macrophages by Mas activation was abolished by both Mas inhibitor A779 and Nrf2 inhibitor ML385. Furthermore, hematoma clearance and neuroprotective effects of AVE0991 treatment were reversed after microglia depletion in ICH. CONCLUSIONS: Mas activation can promote hematoma absorption, ameliorate neurological deficits, alleviate neuron apoptosis, reduced neuroinflammation, and regulate the function and phenotype of microglia/macrophages via Akt/Nrf2 signaling pathway after ICH. Thus, intranasal application of Mas agonist ACE0991 may provide promising strategy for clinical treatment of ICH patients.


Asunto(s)
Hematoma , Accidente Cerebrovascular Hemorrágico , Ratones Endogámicos C57BL , Receptores Acoplados a Proteínas G , Recuperación de la Función , Animales , Ratones , Hematoma/tratamiento farmacológico , Hematoma/patología , Hematoma/metabolismo , Masculino , Accidente Cerebrovascular Hemorrágico/patología , Accidente Cerebrovascular Hemorrágico/tratamiento farmacológico , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Recuperación de la Función/efectos de los fármacos , Recuperación de la Función/fisiología , Proteínas Proto-Oncogénicas/metabolismo , Edema Encefálico/etiología , Edema Encefálico/metabolismo , Edema Encefálico/tratamiento farmacológico , Microglía/efectos de los fármacos , Microglía/metabolismo
7.
World J Gastroenterol ; 30(11): 1588-1608, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38617450

RESUMEN

BACKGROUND: Acute liver failure (ALF) has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis. The silent information regulator sirtuin 1 (SIRT1)-mediated deacetylation affects multiple biological processes, including cellular senescence, apoptosis, sugar and lipid metabolism, oxidative stress, and inflammation. AIM: To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms. METHODS: This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) testing. C57BL/6 mice were also intraperitoneally pretreated with SIRT1, p53, or glutathione peroxidase 4 (GPX4) inducers and inhibitors and injected with lipopolysaccharide (LPS)/D-galactosamine (D-GalN) to induce ALF. Gasdermin D (GSDMD)-/- mice were used as an experimental group. Histological changes in liver tissue were monitored by hematoxylin and eosin staining. ALT, AST, glutathione, reactive oxygen species, and iron levels were measured using commercial kits. Ferroptosis- and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction. SIRT1, p53, and GSDMD were assessed by immunofluorescence analysis. RESULTS: Serum AST and ALT levels were elevated in patients with ALF. SIRT1, solute carrier family 7a member 11 (SLC7A11), and GPX4 protein expression was decreased and acetylated p5, p53, GSDMD, and acyl-CoA synthetase long-chain family member 4 (ACSL4) protein levels were elevated in human ALF liver tissue. In the p53 and ferroptosis inhibitor-treated and GSDMD-/- groups, serum interleukin (IL)-1ß, tumour necrosis factor alpha, IL-6, IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated. In mice with GSDMD knockout, p53 was reduced, GPX4 was increased, and ferroptotic events (depletion of SLC7A11, elevation of ACSL4, and iron accumulation) were detected. In vitro, knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels, the cytostatic rate, and GSDMD expression, restoring SLC7A11 depletion. Moreover, SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group, accompanied by reduced p53, GSDMD, and ACSL4, and increased SLC7A11 and GPX4. Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalN-induced in vitro and in vivo models. CONCLUSION: SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.


Asunto(s)
Fallo Hepático Agudo , Sirtuina 1 , Animales , Humanos , Ratones , Gasderminas , Hierro , Lipopolisacáridos , Fallo Hepático Agudo/inducido químicamente , Ratones Endogámicos C57BL , Fosfolípido Hidroperóxido Glutatión Peroxidasa , Sirtuina 1/genética , Proteína p53 Supresora de Tumor
8.
Innov Aging ; 8(3): igae015, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38618517

RESUMEN

Background and Objectives: In China, rural older adults face a significantly heightened risk of suicide. However, there has been no comprehensive review of the literature examining the risk factors associated with suicide among older people in rural China. Therefore, a comprehensive understanding of risk factors for this phenomenon among rural older people must be gained. We conducted a systematic literature review on risk factors for suicide among older people in rural China. Research Design and Methods: Seven English electronic databases (PubMed, EMBASE, PsycINFO, Cochrane, CINAHL, ScienceDirect, and Web of Science) and 3 Chinese electronic databases (CNKI, CQVIP, and Wanfang) were searched for peer-reviewed articles published in English or Chinese, from inception to July 25, 2022. For data collection, scientific strategies were used for searching and selecting literature within the electronic databases. The collected data were then synthesized using the thematic analysis method. The study was conducted under PRISMA 2020 guidelines. Results: The final analysis included 16 studies. The identified risk factors were categorized under 6 themes: navigating the challenges of illness, unmet basic needs, experiencing abuse from children, feelings of loneliness, negative life events, and altruistic motivation to benefit children. Discussion and Implications: Multiple factors affect suicide among older people in rural China. This invaluable information can be used to develop targeted prevention strategies particularly relevant to this age group.

9.
Front Microbiol ; 15: 1368215, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38605716

RESUMEN

Introduction: The cooperation among members of microbial communities based on the exchange of public goods such as 20 protein amino acids (AAs) has attracted widespread attention. However, little is known about how AAs availability affects interactions among members of complex microbial communities and the structure and function of a community. Methods: To investigate this question, trace amounts of AAs combinations with different synthetic costs (low-cost, medium-cost, high-cost, and all 20 AAs) were supplemented separately to acetate-degrading thermophilic methanogenic reactors, and the differences in microbial community structure and co-occurring networks of main members were compared to a control reactor without AA supplementation. Results: The structure of the microbial community and the interaction of community members were influenced by AAs supplementation and the AAs with different synthetic costs had different impacts. The number of nodes, links, positive links, and the average degree of nodes in the co-occurrence network of the microbial communities with AAs supplementation was significantly lower than that of the control without AAs supplementation, especially for all 20 AAs supplementation followed by the medium- and high-cost AAs supplementation. The average proportion of positive interactions of microbial members in the systems supplemented with low-cost, medium-cost, high-cost, all AAs, and the control group were 0.42, 0.38, 0.15, 0.4, and 0.45, respectively. In addition, the ecological functions of community members possibly changed with the supplementation of different cost AAs. Discussion: These findings highlight the effects of AAs availability on the interactions among members of complex microbial communities, as well as on community function.

10.
Artículo en Inglés | MEDLINE | ID: mdl-38597996

RESUMEN

We have previously identified a latent interaction mechanism between non-small cell lung cancer cells (NSCLCC) and their associated macrophages (TAM) mediated by mutual paracrine activation of the HMGB1/RAGE/NF-κB signaling. Activation of this mechanism results in TAM stimulation and PD-L1 upregulation in the NSCLCC. In the present work, we found that free DOX at a low concentration that does not cause DNA damage could activate the HMGB1/RAGE/NF-κB/PD-L1 pathway byinducing oxidative stress. It was thus proposed that a combination of low-dose DOX and a PD-L1 blocker delivered in the NSCLC tumor would achieve synergistic TAM stimulation and thereby synergetic anti-tumor potency. To prove this idea, DOX and BMS-202 (a PD-L1 blocker) were loaded to black phosphorus (BP) nanoparticles after dosage titration to yield the BMS-202/DOX@BP composites that rapidly disintegrated and released drug cargo upon mild photothermal heating at 40 °C. In vitro experiments then demonstrated that low-dose DOX and BMS-202 delivered via BMS-202/DOX@BP under mild photothermia displayed enhanced tumor cell toxicity with a potent synergism only in the presence of TAM. This enhanced synergism was due to an anti-tumor M1-like TAM phenotype that was synergistically induced by low dose DOX plus BMS-202 only in the presence of the tumor cells, indicating the damaged tumor cells to be the cardinal contributor to the M1-like TAM stimulation. In vivo, BMS-202/DOX@BP under mild photothermia exhibited targeted delivery to NSCLC graft tumors in mice and synergistic anti-tumor efficacy of delivered DOX and BMS-202. In conclusion, low-dose DOX in combination with a PD-L1 blocker is an effective strategy to turn TAM against their host tumor cells exploiting the HMGB1/RAGE/NF-κB/PD-L1 pathway. The synergetic actions involved highlight the value of TAM and the significance of modulating tumor cell-TAM cross-talk in tumor therapy. Photothermia-responsive BP provides an efficient platform to translate this strategy into targeted, efficacious tumor therapy.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38624164

RESUMEN

Combined mild-temperature photothermal/chemotherapy has emerged as a highly promising modality for tumor therapy. However, its therapeutic efficacy is drastically compromised by the heat-induced overexpression of heat shock proteins (HSPs) by the cells, which resist heat stress and apoptosis. The purpose of this study was to downregulate HSPs and enhance the mild-temperature photothermal/chemotherapy effect. In detail, the colon cancer cell membrane (CT26M)-camouflaged HSP90 inhibitor ganetespib and the chemotherapeutic agent doxorubicin (DOX)-coloaded hollow mesoporous Prussian blue (HMPB) nanoplatform (named PGDM) were designed for synergistic mild photothermal/chemotherapy via HSP inhibition. In addition to being a photothermal agent with a high efficiency of photothermal conversion (24.13%), HMPB offers a hollow hole that can be filled with drugs. Concurrently, the cancer cell membrane camouflaging enhances tumor accumulation through a homologous targeting mechanism and gives the nanoplatform the potential to evade the immune system. When exposed to NIR radiation, HMPB's photothermal action (44 °C) not only causes tumor cells to undergo apoptosis but also causes ganetespib to be released on demand. This inhibits the formation of HSP90, which enhances the mild photothermal/chemotherapy effect. The results confirmed that the combined treatment regimen of mild photothermal therapy (PTT) and chemotherapy showed a better therapeutic efficacy than the individual treatment methods. Therefore, this multimodal nanoparticle can advance the development of drugs for the treatment of malignancies, such as colon cancer, and has prospects for clinical application.

12.
Plant J ; 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38606500

RESUMEN

Drought stress is one of the dominating challenges to the growth and productivity in crop plants. Elucidating the molecular mechanisms of plants responses to drought stress is fundamental to improve fruit quality. However, such molecular mechanisms are poorly understood in apple (Malus domestica Borkh.). In this study, we explored that the BTB-BACK-TAZ protein, MdBT2, negatively modulates the drought tolerance of apple plantlets. Moreover, we identified a novel Homeodomain-leucine zipper (HD-Zip) transcription factor, MdHDZ27, using a yeast two-hybrid (Y2H) screen with MdBT2 as the bait. Overexpression of MdHDZ27 in apple plantlets, calli, and tomato plantlets enhanced their drought tolerance by promoting the expression of drought tolerance-related genes [responsive to dehydration 29A (MdRD29A) and MdRD29B]. Biochemical analyses demonstrated that MdHDZ27 directly binds to and activates the promoters of MdRD29A and MdRD29B. Furthermore, in vitro and in vivo assays indicate that MdBT2 interacts with and ubiquitinates MdHDZ27, via the ubiquitin/26S proteasome pathway. This ubiquitination results in the degradation of MdHDZ27 and weakens the transcriptional activation of MdHDZ27 on MdRD29A and MdRD29B. Finally, a series of transgenic analyses in apple plantlets further clarified the role of the relationship between MdBT2 and MdHDZ27, as well as the effect of their interaction on drought resistance in apple plantlets. Collectively, our findings reveal a novel mechanism by which the MdBT2-MdHDZ27 regulatory module controls drought tolerance, which is of great significance for enhancing the drought resistance of apple and other plants.

13.
BMC Pregnancy Childbirth ; 24(1): 181, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38454334

RESUMEN

BACKGROUND: Venous thromboembolism (VTE) is most prevalent among parturients following a cesarean section (CS). The objective of this study was to assess the practical utility of bilateral compression ultrasonography (CUS) of the lower limbs, coupled with D-dimer monitoring, in the early diagnosis of VTE within the Han Chinese population. METHODS: Our prospective observational study included 742 women who underwent CUS and D-dimer testing on the first day post-CS. Subsequently, telephone or outpatient follow-ups were conducted until 42 days postpartum. States of hypercoagulation and thrombosis, as indicated by CUS, were classified as CUS abnormal. A D-dimer level ≥ 3 mg/l was considered the D-dimer warning value. Early ambulation and mechanical prophylaxis were universally recommended for all parturients post-CS. A sequential diagnostic strategy, based on the 2015 RCOG VTE risk-assessment tool, was employed. Therapeutic doses of low-molecular-weight heparin (LMWH) were administered for the treatment of thromboembolic disease. Prophylactic doses of LMWH were given for VTE prophylaxis in parturients with hypercoagulative status accompanied by D-dimer levels ≥ 3 mg/l. All high-risk women (RCOG score ≥ 4 points) were additionally treated with preventive LMWH. Statistical analyses were conducted using the R statistical software, with a two-sided P value < 0.05 considered statistically significant. RESULTS: Fifteen cases of VTE and 727 instances without VTE were observed. The overall VTE rate post-CS was 2.02% (15/742), with 66.7% (10/15) being asymptomatic. Eleven patients received a VTE diagnosis on the first postpartum day. Among the 41 parturients exhibiting hypercoagulation ultrasound findings and D-dimer levels ≥ 3 mg/l, despite receiving pharmacological VTE prophylaxis with LMWH, 4.88% (2/41) in the high-risk group were eventually diagnosed with VTE. A total of 30.86% (229/742) exhibited normal ultrasound findings and D-dimer levels < 3 mg/l on the first day post-CS, with no VTE occurrences in the postpartum follow-up. According to RCOG's recommendation, 78.03% (579/742) of cesarean delivery women should receive prophylactic anticoagulation, while only 20.62% (153/742) met our criterion for prophylactic anticoagulation. CONCLUSION: The strategy of timely routine bilateral CUS and D-dimer monitoring is conducive to the early diagnosis and treatment of VTE, significantly reducing the use of LMWH in the Chinese Han population.


Asunto(s)
Productos de Degradación de Fibrina-Fibrinógeno , Trombofilia , Tromboembolia Venosa , Trombosis de la Vena , Humanos , Femenino , Embarazo , Heparina de Bajo-Peso-Molecular/uso terapéutico , Tromboembolia Venosa/diagnóstico por imagen , Tromboembolia Venosa/etiología , Cesárea/efectos adversos , Ultrasonografía , Trombofilia/tratamiento farmacológico , Anticoagulantes/uso terapéutico , Trombosis de la Vena/diagnóstico por imagen , Trombosis de la Vena/etiología , China/epidemiología
14.
Sci Rep ; 14(1): 5871, 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38467664

RESUMEN

The damage behavior of limestone rock masses containing calcite mineral filling under uniaxial compression experimental conditions is unclear, and the fracture mechanism of the rock masses needs to be further explored. In this study, uniaxial compression tests were conducted on limestone rock specimens containing veined calcite by combining acoustic emission and digital image correlation techniques. The effects of veined calcite on the generation and development of cracks on the surface of the specimens until the formation of macroscopic penetration and the strength properties of the rock mass were analyzed. The results showed that the transversely distributed veined calcite caused significant stress concentrations in the rock specimens. The longitudinally distributed veined calcite caused cracks in the specimens or influenced the expansion path of the longitudinal principal cracks. The final damage pattern of the specimens didn't differ significantly from that of conventional rock masses due to the presence of veined calcite. The presence of the veined calcite had effect on the uniaxial compressive capacity of the rock, but the load variation process of the specimen with time still conformed to the load variation pattern during the uniaxial compressive test of conventional rocks.

15.
J Hazard Mater ; 469: 133997, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38508115

RESUMEN

Maternal exposure to glucocorticoids has been associated with adverse outcomes in offspring. However, the consequences and mechanisms of gestational exposure to prednisone on susceptibility to osteoporosis in the offspring remain unclear. Here, we found that gestational prednisone exposure enhanced susceptibility to osteoporosis in adult mouse offspring. In a further exploration of myogenic mechanisms, results showed that gestational prednisone exposure down-regulated FNDC5/irisin protein expression and activation of OPTN-dependent mitophagy in skeletal muscle of adult offspring. Additional experiments elucidated that activated mitophagy significantly inhibited the expression of FNDC5/irisin in skeletal muscle cells. Likewise, we observed delayed fetal bone development, downregulated FNDC5/irisin expression, and activated mitophagy in fetal skeletal muscle upon gestational prednisone exposure. In addition, an elevated total m6A level was observed in fetal skeletal muscle after gestational prednisone exposure. Finally, gestational supplementation with S-adenosylhomocysteine (SAH), an inhibitor of m6A activity, attenuated mitophagy and restored FNDC5/irisin expression in fetal skeletal muscle, which in turn reversed fetal bone development. Overall, these data indicate that gestational prednisone exposure increases m6A modification, activates mitophagy, and decreases FNDC5/irisin expression in skeletal muscle, thus elevating osteoporosis susceptibility in adult offspring. Our results provide a new perspective on the earlier prevention and treatment of fetal-derived osteoporosis.


Asunto(s)
Fibronectinas , Osteoporosis , Humanos , Ratones , Femenino , Animales , Embarazo , Prednisona/metabolismo , Fibronectinas/metabolismo , Exposición Materna , Mitofagia , Músculo Esquelético/metabolismo , Factores de Transcripción/metabolismo , Osteoporosis/inducido químicamente
16.
J Colloid Interface Sci ; 665: 1-9, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38513403

RESUMEN

The cancer therapeutic efficacy of the peroxidase (POD)-mimicking nanozyme-based monotherapy is significantly hindered due to insufficient intratumoral hydrogen peroxide (H2O2) and glutathione (GSH) consumption effect on reactive oxygen species (ROS). In this study, we present the development of poly(o-phenylenediamine)@gold nanoparticles (AuNPs) (PoPD@Au) nanocomposites for multifunctional catalytic-photothermal therapy. These nanocomposites exhibit triple distinct nanozymatic activities, i.e., POD-like activity that catalyzes H2O2 to ROS, glucose oxidase (GOx)-like activity that supplements endogenous H2O2, and GSH depleting activity that decreases the ROS consumption efficiency. This open source and reduce expenditure strategy for ROS generation allows for the amplification of tumor oxidative stress, thereby enhancing anti-tumor efficiency. Additionally, the PoPD@Au nanocomposites demonstrate outstanding photothermal conversion efficiency, contributing to the synergistic effect between PoPD and AuNPs. Moreover, we reveal the improved photothermal performance of PoPD@Au triggered by the tumor microenvironment pH, which provides additional benefits for targeted catalytic-photothermal therapy. This "four-in-one" design of PoPD@Au enables efficient anti-tumor effects both in vitro and in vivo, making it a universal strategy for engineering catalytic-photothermal therapeutic nanoagents.


Asunto(s)
Nanopartículas del Metal , Neoplasias , Humanos , Oro/farmacología , Peróxido de Hidrógeno , Terapia Fototérmica , Especies Reactivas de Oxígeno , Glutatión , Neoplasias/terapia , Línea Celular Tumoral , Microambiente Tumoral
17.
Artículo en Inglés | MEDLINE | ID: mdl-38538036

RESUMEN

BACKGROUND: Nurses play a unique and critical role in palliative care, and it is noteworthy that nurses often encounter ethical dilemmas in this field. OBJECTIVE: This review aims to conduct a summarised synthesis of the latest research on the ethical considerations nurses faced in palliative care. METHODS: We conducted a rigorous systematic review of relevant existing studies published in high-quality English peer-reviewed journals from January 2017 to July 2023. We identified a total of 4492 articles (1029 in Web of Science, 1570 in PubMed and 1893 in Science Direct). Out of these, only 13 studies met the inclusion criteria. RESULTS: Following the thematic analysis, the ethical considerations reported in these 13 studies were grouped into three main themes and four subthemes: ethical issues in communication (ethical issues in communication with patients, ethical issues in communication with families), ethical issues in decision-making (autonomy, dignity) and moral distress in palliative care. CONCLUSION: This study elaborated on the ethical challenges faced by nurses in their communication with patients and families as well as decision-making and analysed the causes and effects of ethical distress, hoping to give a hand to ethical issues for nurses' work in palliative care.

18.
BMC Cardiovasc Disord ; 24(1): 178, 2024 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-38521897

RESUMEN

AIMS: The current management of patients with atrial fibrillation (AF) and concomitant heart failure (HF) remains a significant challenge. Catheter ablation (CA) has been shown to improve left ventricular ejection fraction (LVEF) in these patients, but which patients can benefit from CA is still poorly understood. The aim of our study was to determine the predictors of improved ejection fraction in patients with persistent atrial fibrillation (PeAF) complicated with HF undergoing CA. METHODS AND RESULTS: A total of 435 patients with persistent AF underwent an initial CA between January 2019 and March 2023 in our hospital. We investigated consecutive patients with left ventricular systolic dysfunction (LVEF < 50%) measured by transthoracic echocardiography (TTE) within one month before CA. According to the LVEF changes at 6 months, these patients were divided into an improved group (fulfilling the '2021 Universal Definition of HF' criteria for LVEF recovery) and a nonimproved group. Eighty patients were analyzed, and the improvement group consisted of 60 patients (75.0%). In the univariate analysis, left ventricular end-diastolic diameter (P = 0.005) and low voltage zones in the left atrium (P = 0.043) were associated with improvement of LVEF. A receiver operating characteristic analysis determined that the suitable cutoff value for left ventricular end-diastolic diameter (LVDd) was 59 mm (sensitivity: 85.0%, specificity: 55.0%, area under curve: 0.709). A multivariate analysis showed that LVDd (OR = 0.85; 95% CI: 0.76-0.95, P = 0.005) and low voltage zones (LVZs) (OR = 0.26; 95% CI: 0.07-0.96, P = 0.043) were significantly independently associated with the improvement of LVEF. Additionally, parameters were significantly improved regarding the left atrial diameter, LVDd and ventricular rate after radiofrequency catheter ablation (all p < 0.05). CONCLUSIONS: The improvement of left ventricular ejection fraction (LVEF) occurred in 75.0% of patients. Our study provides additional evidence that LVDd < 59 mm and no low voltage zones in the left atrium can be used to jointly predict the improvement of LVEF after atrial fibrillation ablation.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Insuficiencia Cardíaca , Disfunción Ventricular Izquierda , Humanos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Fibrilación Atrial/complicaciones , Función Ventricular Izquierda , Volumen Sistólico , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/complicaciones , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/complicaciones , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , Resultado del Tratamiento
19.
World J Clin Cases ; 12(7): 1356-1364, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38524505

RESUMEN

BACKGROUND: While most complications of cervical surgery are reversible, some, such as symptomatic postoperative spinal epidural hematoma (SEH), which generally occurs within 24 h, are associated with increased morbidity and mortality. Delayed neurological dysfunction is diagnosed in cases when symptoms present > 3 d postoperatively. Owing to its rarity, the risk factors for delayed neurological dysfunction are unclear. Consequently, this condition can result in irreversible neurological deficits and serious consequences. In this paper, we present a case of postoperative SEH that developed three days after hematoma evacuation. CASE SUMMARY: A 68-year-old man with an American Spinal Injury Association (ASIA) grade C injury was admitted to our hospital with neck pain and tetraplegia following a fall. The C3-C7 posterior laminectomy and the lateral mass screw fixation surgery were performed on the tenth day. Postoperatively, the patient showed no changes in muscle strength or ASIA grade. The patient experienced neck pain and subcutaneous swelling on the third day postoperatively, his muscle strength decreased, and his ASIA score was grade A. Magnetic resonance imaging showed hypointense signals on T1 weighted image (T1WI) and T2WI located behind the epidural space, with spinal cord compression. Emergency surgical intervention for the hematoma was performed 12 h after onset. Although hypoproteinemia and pleural effusion did not improve in the perioperative period, the patient recovered to ASIA grade C on day 30 after surgery, and was transferred to a functional rehabilitation exercise unit. CONCLUSION: This case shows that amelioration of low blood albumin and pleural effusion is an important aspect of the perioperative management of cervical surgery. Surgery to relieve the pressure on the spinal cord should be performed as soon as possible to decrease neurological disabilities.

20.
Artículo en Inglés | MEDLINE | ID: mdl-38530452

RESUMEN

PURPOSE: To investigate the alterations in extraocular muscles (EOMs) by magnetic resonance imaging (MRI) among patients diagnosed with Duane retraction yndrome (DRS) and congenital fibrosis of the extraocular muscles (CFEOM), who present with various cranial nerve anomalies in an attempt to enhance the clinical diagnostic process. METHODS: A case-control study was conducted to evaluate 27 patients with DRS and 14 patients with CFEOM. All patients underwent MRI scans of the brainstem and orbital examination. Neurodevelopmental assessments were conducted through MRI, and maximum cross-sectional area and volumes of EOMs were obtained. Three types of models were constructed using machine learning decision tree algorithms based on EOMs to predict disease diagnosis, cranial nerve abnormalities, and clinical subtypes. RESULTS: Patients with bilateral CN VI abnormalities had smaller volumes of LR, MR, and IR muscles compared to those with unilateral involvement (P < 0.05). Similarly, patients with CFEOM and unilateral third cranial nerve abnormalities had a smaller maximum cross-section of the affected eye's SR compared to the contralateral eye (P < 0.05). In patients with both CN III and CN VI abnormalities, the volume of SR was smaller than in patients with CN III abnormalities alone (P < 0.05). The prediction model using EOMs volume showed a diagnostic precision of 82.5% for clinical cases and 60.1% for predicting cranial nerve abnormalities. Nonetheless, the precision for identifying clinical subtypes was relatively modest, at only 41.7%. CONCLUSION: The distinctive volumetric alterations in EOMs among individuals exhibiting distinct cranial nerve anomalies associated with DRS or CFEOM provide valuable diagnostic insights into to Congenital Cranial Neurodevelopmental Disorders (CCDDs). MRI analysis of EOMs should thus be regarded as a crucial diagnostic modality.

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