RESUMEN
The question of whether all materials can solidify into the glassy form proposed by Turnbull half a century ago remains unsolved. Some of the simplest systems of monatomic metals have not been vitrified, especially the close-packed face-centred cubic metals. Here we report the vitrification of gold, which is notoriously difficult to be vitrified, and several similar close-packed face-centred cubic and hexagonal metals using a method of picosecond pulsed laser ablation in a liquid medium. The vitrification occurs through the rapid cooling during laser ablation and the inhibition of nucleation by the liquid medium. Using this method, a large number of atomic configurations, including glassy configurations, can be generated simultaneously, from which a stable glass state can be sampled. Simulations demonstrate that the favourable stability of monatomic metals stems from the strong topological frustration of icosahedra-like clusters. Our work breaks the limitation of the glass-forming ability of matter, indicating that vitrification is an intrinsic property of matter and providing a strategy for the preparation and design of metallic glasses from an atomic configuration perspective.
RESUMEN
BACKGROUND: Intracerebral hemorrhage (ICH) is a common stroke type with high morbidity and mortality. There are mainly three surgical methods for treating ICH. Unfortunately, thus far, no specific surgical method has been proven to be the most effective. We carried out this study to investigate whether minimally invasive surgeries with endoscopic surgery or stereotactic aspiration (frameless navigated aspiration) will improve functional outcomes in patients with supratentorial ICH compared with small-bone flap craniotomy. METHODS: In this parallel-group multicenter randomized controlled trial conducted at 16 centers, patients with supratentorial hypertensive ICH were randomized to receive endoscopic surgery, stereotactic aspiration, or craniotomy at a 1:1:1 ratio from July 2016 to June 2022. The follow-up duration was 6 months. Patients were randomized to receive endoscopic evacuation, stereotactic aspiration, or small-bone flap craniotomy. The primary outcome was favorable functional outcome, defined as the proportion of patients who achieved a modified Rankin scale (mRS) score of 0-2 at the 6-month follow-up. RESULTS: A total of 733 patients were randomly allocated to three groups: 243 to the endoscopy group, 247 to the aspiration group, and 243 to the craniotomy group. Finally, 721 patients (239 in the endoscopy group, 246 in the aspiration group, and 236 in the craniotomy group) received treatment and were included in the intention-to-treat analysis. Primary efficacy analysis revealed that 73 of 219 (33.3%) in the endoscopy group, 72 of 220 (32.7%) in the aspiration group, and 47 of 212 (22.2%) in the craniotomy group achieved favorable functional outcome at the 6-month follow-up (P = .017). We got similar results in subgroup analysis of deep hemorrhages, while in lobar hemorrhages the prognostic outcome was similar among three groups. Old age, deep hematoma location, large hematoma volume, low preoperative GCS score, craniotomy, and intracranial infection were associated with greater odds of unfavorable outcomes. The mean hospitalization expenses were ¥92,420 in the endoscopy group, ¥77,351 in the aspiration group, and ¥100,947 in the craniotomy group (P = .000). CONCLUSIONS: Compared with small bone flap craniotomy, endoscopic surgery and stereotactic aspiration improved the long-term outcome of hypertensive ICH, especially deep hemorrhages. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02811614.
Asunto(s)
Craneotomía , Hemorragia Intracraneal Hipertensiva , Procedimientos Quirúrgicos Mínimamente Invasivos , Humanos , Masculino , Femenino , Persona de Mediana Edad , Hemorragia Intracraneal Hipertensiva/cirugía , Anciano , Craneotomía/métodos , Resultado del Tratamiento , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Endoscopía/métodos , AdultoRESUMEN
Car-sharing systems require accurate demand prediction to ensure efficient resource allocation and scheduling decisions. However, developing precise predictive models for vehicle demand remains a challenging problem due to the complex spatio-temporal relationships. This paper introduces USTIN, the Unified Spatio-Temporal Inference Prediction Network, a novel neural network architecture for demand prediction. The model consists of three key components: a temporal feature unit, a spatial feature unit, and a spatio-temporal feature unit. The temporal unit utilizes historical demand data and comprises four layers, each corresponding to a different time scale (hourly, daily, weekly, and monthly). Meanwhile, the spatial unit incorporates contextual points of interest data to capture geographic demand factors around parking stations. Additionally, the spatio-temporal unit incorporates weather data to model the meteorological impacts across locations and time. We conducted extensive experiments on real-world car-sharing data. The proposed USTIN model demonstrated its ability to effectively learn intricate temporal, spatial, and spatiotemporal relationships, and outperformed existing state-of-the-art approaches. Moreover, we employed negative binomial regression with uncertainty to identify the most influential factors affecting car usage.
RESUMEN
BACKGROUND: Sepsis is defined as a systemic inflammatory response to microbial infections with multiple organ dysfunction. This study analysed untargeted metabolomics combined with proteomics of serum from patients with sepsis to reveal the underlying pathological mechanisms involved in sepsis. METHODS: A total of 63 patients with sepsis and 43 normal controls were enrolled from a prospective multicentre cohort. The biological functions of the metabolome were assessed by coexpression network analysis. A molecular network based on metabolomics and proteomics data was constructed to investigate the key molecules. RESULTS: Untargeted metabolomics analysis revealed widespread dysregulation of amino acid metabolism, which regulates inflammation and immunity, in patients with sepsis. Seventy-three differentially expressed metabolites (|log2 fold change| > 1.5, adjusted P value < 0.05 and variable importance in the projection (VIP) > 1.5) that could predict sepsis were identified. External validation of the hub metabolites was consistent with the derivation results (area under the receiver operating characteristic curve (AUROC): 0.81-0.96/0.62-1.00). The pentose phosphate pathway was found to be related to sepsis-associated encephalopathy. Phenylalanine metabolism was associated with sepsis-associated acute kidney injury. The key molecular alterations of the multiomics network in sepsis compared to normal controls implicate acute inflammatory response, platelet degranulation, myeloid cell activation involved in immune response and phenylalanine, tyrosine and tryptophan biosynthesis, and arginine biosynthesis. CONCLUSIONS: Integrated analysis of untargeted metabolomics and proteomics revealed characteristic metabolite and protein alterations in sepsis, which were mainly involved in inflammation-related pathways and amino acid metabolism. This study depicted the pathological characteristics and pathways involved in sepsis and potential therapeutic targets.
Asunto(s)
Proteómica , Sepsis , Aminoácidos , Humanos , Metabolómica/métodos , Estudios Prospectivos , Sepsis/complicacionesRESUMEN
OBJECTIVE: Endoplasmic reticulum stress (ERS) might play a pivotal role in the persistence of metabolic syndrome (MS). Lipopolysaccharide (LPS) derived from various gram-negative bacteria could result in the ERS. Therefore, we aimed to investigate the association between LPS and ERS in MS. METHOD: We enrolled 86 patients with MS and 42 healthy people aged 35-65 years. Body weight, waist circumference, blood pressure were measured. LPS, LBP and inflammation factors, fasting plasma glucose (FPG), insulin, total cholesterol (TC), triglyceride, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), free fatty acid (FFA) were analyzed in blood plasma of patient's cohort. Body mass index (BMI) and HOMA-IR were calculated. The mRNA and protein expression of ERS GRP78, IRE1α, ASK1 and IKKß, JNK1 were measured in blood plasma of patient's cohort by RT-PCR and Elisa. MS was defined by the updated National Cholesterol Education Program Adult Treatment Panel III criterion for Asian Americans. RESULTS: BMI, waist circumference, blood pressure, FPG, insulin, HOMA-IR, TC, triglyceride, HDL-C, LDL-C, FFA and LPS, LBP, TNF-α, CRP, IL-1, IL-6, MCP-1 were significantly higher in patients with MS than healthy people (P < 0.001). The correlation analysis suggested that LPS were associated with TNF-α, IL-1, IL-6, MCP-1, LBP, FFA, HOMA-IR potently (P < 0.05). The marker gene and protein expressions of ERS (GRP78, IRE1α, ASK1, IKKß and JNK) were significantly overexpressed in patients with MS and were positive correlation with LPS (P < 0.05). CONCLUSION: LPS may play an important role in mediating chronic low-grade inflammation by activating the ERS GRP78-IRE1α-ASK1 signaling pathway, contributing to the persistence of MS.
Asunto(s)
Chaperón BiP del Retículo Endoplásmico/metabolismo , Endorribonucleasas/metabolismo , Lipopolisacáridos/toxicidad , MAP Quinasa Quinasa Quinasa 5/metabolismo , Síndrome Metabólico/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Chaperón BiP del Retículo Endoplásmico/genética , Endorribonucleasas/genética , Femenino , Humanos , MAP Quinasa Quinasa Quinasa 5/genética , Masculino , Síndrome Metabólico/genética , Persona de Mediana Edad , Proteínas Serina-Treonina Quinasas/genéticaRESUMEN
The anti-senescence function of genistein is related to inhibiting oxidative stress, however, the mechanism has not been clarified. The present study aimed to explore the effects of genistein on oxidized low-density lipoprotein (ox-LDL)-induced endothelial senescence and the role of the sirtuin-1 (SIRT1)-66-kDa Src homology 2 domain-containing protein (p66Shc)-forkhead box protein O3 (Foxo3a) pathways in the process. In this paper, human umbilical vein endothelial cells were pretreated with 1000 nM genistein for 30 min and then incubated with 50 mg/L ox-LDL for another 12 h; meanwhile, the functions of adenovirus-mediated overexpression of p66shc and small interfering RNA-mediated silencing of SIRT1 were investigated. Results showed that genistein pretreatment alleviated ox-LDL-induced mitochondrial reactive oxygen species, the levels of oxidatively modified DNA (8-OHdG) and pai-1, and the activity of SA-ß-gal, which was associated with mitigating p66shc. Further studies indicated the inhibitory effect of genistein on p66shc was correlated with suppressing the acetylation and phosphorylation of p66shc, and ameliorating its mitochondrial translocation by activating SIRT1. Moreover, the inactivated p66shc could enhance the activity of Foxo3a via restraining the phosphorylation and triggering nucleus accumulation. The study demonstrates genistein could prevent ox-LDL-induced mitochondrial oxidative stress and senescence through the SIRT1-p66shc-Foxo3a pathways.
Asunto(s)
Senescencia Celular/efectos de los fármacos , Proteína Forkhead Box O3/metabolismo , Genisteína/farmacología , Lipoproteínas LDL/metabolismo , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Sirtuina 1/metabolismo , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src/metabolismo , Proteína Forkhead Box O3/genética , Células Endoteliales de la Vena Umbilical Humana , Humanos , Lipoproteínas LDL/genética , Sirtuina 1/genética , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src/genéticaRESUMEN
OBJECTIVE: To increase access to health interventions and healthcare services for patients in resource-constrained settings, strategies such as telemedicine must be implemented for the allocation of medical resources across geographic boundaries. Telecollaboration is the dominant form of surgical telemedicine. In this study, the authors report and evaluate a novel mobile internet-based mixed-reality interactive telecollaboration (MIMIT) system as a new paradigm for telemedicine and validate its clinical feasibility. METHODS: The application of this system was demonstrated for long-distance, real-time collaboration of neuroendoscopic procedures. The system consists of a local video processing workstation, a head-mounted mixed-reality display device, and a mobile remote device, connected over mobile internet (4G or 5G), allowing global point-to-point communication. Using this system, 20 cases of neuroendoscopic surgery were performed and evaluated. The system setup, composite video latency, technical feasibility, clinical implementation, and future potential business model were analyzed and evaluated. RESULTS: The MIMIT system allows two surgeons to perform complex visual and verbal communication during the operation. The average video delay time is 184.25 msec (range 160-230 msec) with 4G mobile internet, and 23.25 msec (range 20-26 msec) with 5G mobile internet. Excellent image resolution enabled remote neurosurgeons to visualize all critical anatomical structures intraoperatively. Remote instructors could easily make marks on the surgical view; then the composite image, as well as the audio conversation, was transferred to the local surgeon. In this way, a real-time, long-distance collaboration can occur. This system was used for 20 neuroendoscopic surgeries in various cities in China and even across countries (Boston, Massachusetts, to Jingzhou, China). Its simplicity and practicality have been recognized by both parties, and there were no technically related complications recorded. CONCLUSIONS: The MIMIT system allows for real-time, long-distance telecollaborative neuroendoscopic procedures and surgical training through a commercially available and inexpensive system. It enables remote experts to implement real-time, long-distance intraoperative interaction to guide inexperienced local surgeons, thus integrating the best medical resources and possibly promoting both diagnosis and treatment. Moreover, it can popularize and improve neurosurgical endoscopy technology in more hospitals to benefit more patients, as well as more neurosurgeons.
Asunto(s)
Neuroendoscopía , Telemedicina , Estudios de Factibilidad , Humanos , Internet , NeurocirujanosRESUMEN
Pulmonary rehabilitation (PR) is an essential method for Acute exacerbation in chronic obstructive pulmonary disease (AECOPD) recovery. We perform a meta-analysis to compare early PR with usual care. A literature search was performed through these databases: PubMed, MEDLINE database, Google Scholar, Cochrane, Embase from inception to July 2021. Eligible trials were clinical randomized controlled trials comparing the effects of early PR and usual care in AECOPD patients. The primary endpoint of this meta-analysis was FEV1% predicted, 6-min walk test (6MWD), modified Medical Research Council (mMRC) and George Respiratory Questionnaire-total (SGRQ-total). The secondary outcomes were borg dyspnea score, short-form 36 health survey questionnaire physical (SF-36 physical) and SF-36 mental. We included 13 RCTs with a total of 866 patients. There were no significant effects of the PR group on measures of FEV1% predicted (MD = 0.50, 95%CI -1.43 to 2.44, Z = 0.51, p = 0.61), borg dyspnea score (MD = -0.88, 95%CI -1.89 to 0.13, Z = 1.71, p = 0.09) and SF-36 mental (MD = 4.34, 95%CI -1.64 to 10.32, Z = 1.42, p = 0.16) compared with usual care. PR group achieved better 6MWD (MD = 97.58, 95%CI 17.21 to 177.96, Z = 2.38, p = 0.02), mMRC (MD = -0.36, 95%CI -0.52 to -0.21, Z = 4.56, p Ë 0.00001), SGRQ-total (MD= -9.67, 95%CI -16.23 to -3.11, Z = 2.89, p = 0.004) and SF-36 physical (MD = 4.98, 95%CI 0.60 to 9.35, Z = 2.23, p = 0.03) compared with usual care group. Early PR in AECOPD patients would lead to better 6MWD, mMRC, SGRQ-total and SF-36 physical. But there were no significant effects of the PR group on measures of FEV1% predicted, borg dyspnea score and SF-36 mental.
Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Disnea/etiología , Humanos , Enfermedad Pulmonar Obstructiva Crónica/rehabilitación , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Prueba de PasoRESUMEN
We aimed to detect the expression pattern of long non-coding RNA (lncRNA) FGD5-AS1 in gastric cancer (GC) samples and its impact on driving the development of GC. FGD5-AS1 levels in 66 cases of GC tissues and paracancerous ones were detected. Its influences on clinical features and prognosis in GC patients were analyzed. In AGS and SGC-7901 cells with FGD5-AS1 knockdown, phenotype changes were assessed through cell counting kit-8 (CCK-8), Transwell and wound healing assay. The downstream target of FGD5-AS1 was searched by a bioinformatics tool and confirmed by dual-luciferase reporter assay. Their interaction in regulating the malignant development of GC was finally explored. FGD5-AS1 was upregulated in GC tissues compared to paracancerous ones. GC patients expressing a high level of FGD5-AS1 had higher risk of lymphatic metastasis or distant metastasis and worse prognosis than those with a low level. Knockdown of FGD5-AS1 weakened proliferative and metastatic abilities in AGS and SGC-7901 cells. FZD3 was the downstream target of FGD5-AS1. Protein levels of FZD3 and FZD5 were upregulated, while b-catenin, TGF-b and MMP9 were downregulated in GC cells with FGD5-AS1 knockdown. Knockdown of FZD3 abolished the regulatory effects of FGD5-AS1 on malignant phenotypes of GC cells. FGD5-AS1 is upregulated in GC samples, which is linked to metastasis and prognosis in GC. It drives proliferative and metastatic abilities in GC cells via negatively interacting with FZD3.
Asunto(s)
MicroARNs , ARN Largo no Codificante , Neoplasias Gástricas , Línea Celular Tumoral , Proliferación Celular/genética , Receptores Frizzled/genética , Receptores Frizzled/metabolismo , Regulación Neoplásica de la Expresión Génica , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Humanos , MicroARNs/genética , ARN Largo no Codificante/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologíaRESUMEN
Background: Sepsis, as a clinical emergency, usually causes multiorgan dysfunction and can lead to high mortality. Establishment of specific and sensitive biomarkers for early diagnosis is critical to identify patients who would benefit from targeted therapy. In this study, we investigated this syndrome by analyzing the transcriptome of peripheral blood mononuclear cells (PBMCs) from patients with sepsis and identified sepsis-specific biomarkers. Methods: In this study, a total of 87 patients with sepsis and 40 healthy controls from a prospective multicenter cohort were enrolled. Samples from 44 subjects (24 patients with sepsis and 20 healthy controls) were sequenced and the remaining patients were included in the validation group. Using high-throughput sequencing, a gene expression profile of PBMCs from patients with sepsis was generated to elucidate the pathophysiology of sepsis and identify sepsis-specific biomarkers. Results: Principal component analysis (PCA) and unsupervised hierarchical cluster analysis showed that patients with sepsis separated from healthy controls. A total of 1639 differentially expressed genes (DEGs) were identified (|log2 fold change|>2, adjusted P value <0.05) between these two groups, with 1278 (78.0%) upregulated and 361 (22.0%) downregulated in patients with sepsis. Gene Ontology (GO) analysis of the upregulated DEGs identified 194 GO terms that were clustered into 27 groups, and analysis of the downregulated DEGs identified 20 GO terms that were clustered into 4 groups. Four unique genes were identified that could be predictive of patients with sepsis. External validation of the four genes using quantitative real-time polymerase chain reaction (qRT-PCR) was consistent with the results of mRNA sequencing, revealing their potential in sepsis diagnosis. Conclusions: The transcriptome characteristics of PBMCs, which were significantly altered in sepsis patients, provide new insights into sepsis pathogenesis. The four identified gene expression changes differentiated patients with sepsis from healthy subjects, which could serve as a convenient tool contributing to sepsis diagnosis.
Asunto(s)
Regulación de la Expresión Génica/inmunología , Leucocitos Mononucleares/metabolismo , Sepsis/diagnóstico , Transcriptoma/inmunología , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Estudios de Casos y Controles , Análisis por Conglomerados , Biología Computacional , Femenino , Perfilación de la Expresión Génica , Humanos , Leucocitos Mononucleares/inmunología , Masculino , Puntuaciones en la Disfunción de Órganos , Análisis de Componente Principal , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa , Sepsis/sangre , Sepsis/genética , Sepsis/inmunologíaRESUMEN
Gut microbiota alterations manifest as intermittent hypoxia and fragmented sleep, thereby mimicking obstructive sleep apnea-hypopnea syndrome (OSAHS). Here, we sought to perform the first direct survey of gut microbial dysbiosis over a range of apnea-hypopnea indices (AHI) among patients with OSAHS. We obtained fecal samples from 93 patients with OSAHS [5 < AHI ≤ 15 (n=40), 15 < AHI ≤ 30 (n=23), and AHI ≥ 30 (n=30)] and 20 controls (AHI ≤ 5) and determined the microbiome composition via 16S rRNA pyrosequencing and bioinformatics analysis of variable regions 3-4. We measured fasting levels of homocysteine (HCY), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α). Results revealed gut microbial dysbiosis in several patients with varying severities of OSAHS, reliably separating them from controls with a receiver operating characteristic-area under the curve (ROC-AUC) of 0.789. Functional analysis in the microbiomes of patients revealed alterations; additionally, decreased in short-chain fatty acid (SCFA)-producing bacteria and increased pathogens, accompanied by elevated levels of IL-6. Lactobacillus levels correlated with HCY levels. Stratification analysis revealed that the Ruminococcus enterotype posed the highest risk for patients with OSAHS. Our results show that the presence of an altered microbiome is associated with HCY among OSAHS patients. These changes in the levels of SCFA affect the levels of pathogens that play a pathophysiological role in OSAHS and related metabolic comorbidities.
Asunto(s)
Bacterias/aislamiento & purificación , Microbioma Gastrointestinal , Intestinos/microbiología , Enfermedades Metabólicas/microbiología , Apnea Obstructiva del Sueño/microbiología , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Comorbilidad , Disbiosis , Heces/microbiología , Femenino , Homocisteína/sangre , Interacciones Huésped-Patógeno , Humanos , Masculino , Enfermedades Metabólicas/sangre , Enfermedades Metabólicas/diagnóstico , Enfermedades Metabólicas/epidemiología , Persona de Mediana Edad , Apnea Obstructiva del Sueño/sangre , Apnea Obstructiva del Sueño/diagnóstico , Apnea Obstructiva del Sueño/epidemiologíaRESUMEN
The anti-senescence activity of genistein is associated with inducing autophagy; however, the underlying mechanisms are not fully understood. In this study, human umbilical vein endothelial cells (HUVECs) were pretreated with genistein (1000 nM) for 30 min and then exposed to ox-LDL (50 mg/L) for another 12 h. The study found that genistein inhibited the ox-LDL-induced senescence (reducing the levels of P16 and P21 protein, and the activity of SA-ß-gal); meanwhile, the effect of genistein was bound up with enhancing autophagic flux (increasing LC3-II, and decreasing the level of P62, p-mTOR and p-P70S6K). Moreover, SIRT1/LKB1/AMPK pathway was involved in genistein accelerating autophagic flux and mitigating senescence in HUVECs. The present study illustrated that genistein was a promising therapeutic agent to delay aging process and extend longevity.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Autofagia/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Genisteína/farmacología , Lipoproteínas LDL/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Sirtuina 1/metabolismo , Quinasas de la Proteína-Quinasa Activada por el AMP , Células Endoteliales de la Vena Umbilical Humana , HumanosRESUMEN
Activation of the stimulator of interferon genes (STING) pathway by both exogenous and endogenous cytosolic DNA results in the production of interferon beta (IFN-ß) and is required for the generation of cytotoxic T-cell priming against tumor antigens. In the clinical setting, pharmacological stimulation of the STING pathway has the potential to synergize with immunotherapy antibodies by boosting anti-tumor immune responses. We report the discovery of two highly potent cyclic dinucleotide STING agonists, IACS-8803 and IACS-8779, which show robust activation of the STING pathway in vitro and a superior systemic anti-tumor response in the B16 murine model of melanoma when compared to one of the clinical benchmark compounds.
Asunto(s)
Antineoplásicos/química , Compuestos Heterocíclicos/química , Interferón beta/metabolismo , Melanoma Experimental/inmunología , Melanoma/inmunología , Nucleótidos Cíclicos/antagonistas & inhibidores , Animales , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Línea Celular , Citosol/metabolismo , Compuestos Heterocíclicos/farmacología , Humanos , Inmunidad Innata , Inmunoterapia/métodos , Proteínas de la Membrana/inmunología , Ratones , Fosfatos/metabolismo , Transducción de Señal , Microambiente TumoralRESUMEN
Prolonged storage of technical abamectin as well as avermectin B1a samples yielded a previously unknown derivative, designated here as compound 1. Detailed NMR analysis and X-ray crystallography allowed us to determine the structure of this compound and revealed the presence of a hydroperoxide group (-OOH) attached stereoselectively with configuration S to the C-8a carbon. This surprising result involves the formation of the peroxide bond in solid crystalline avermectin B1a upon exposure to air with no involvement of light or recognized catalytic factors and is consistent with a topotactic mechanism for the oxidation reaction. Compound 1 is stable in the absence of reducing agents and has potential as a starting point in structural modification of the tetrahydrofuran ring of avermectin B1a. It could also serve as a marker in assessing the quality of stored technical abamectin.
Asunto(s)
Peróxido de Hidrógeno/química , Ivermectina/análogos & derivados , Cristalización , Cristalografía por Rayos X , Ivermectina/química , Ivermectina/farmacología , Espectroscopía de Resonancia Magnética/métodos , Estructura Molecular , Oxidación-Reducción , EstereoisomerismoRESUMEN
Currently available data regarding the blood levels of erythropoietin (EPO) in sleep apnea (SA) patients are contradictory. The aim of the present meta-analysis was to evaluate the EPO levels in SA patients via quantitative analysis. A systematic search of Pubmed, Embase, and Web of Science were performed. EPO levels in SA group and control group were extracted from each eligible study. Weight mean difference (WMD) or Standard mean difference (SMD) with 95% confidence interval (CI) was calculated by using fixed-effects or random effect model analysis according to the degree of heterogeneity between studies. A total of 9 studies involving 407 participants were enrolled. The results indicated that EPO levels in SA group were significantly higher than that in control group (SMD 0.61, 95% CI 0.11-1.11, p = 0.016). Significantly higher EPO levels were found in patients with body mass index <30 kg/m2, and cardiovascular complications in the subsequent subgroup analysis (both p < 0.05). High blood EPO levels were found in SA patients in the present meta-analysis.
Asunto(s)
Eritropoyetina , Síndromes de la Apnea del Sueño/sangre , Eritropoyetina/análisis , Eritropoyetina/sangre , Humanos , Estadística como AsuntoRESUMEN
A classic withanolide is defined as a highly oxygenated C28 ergostane-type steroid that is characterized by a C22-hydroxy-C26-oic acid δ-lactone in the nine-carbon side chain. Analysis of the reported (13)C NMR data of classic withanolides with hydroxy groups (C-14, C-17, and C-20) revealed that (1) a hydroxy (C-14 or C-17) substituent significantly alters the chemical shifts (C-7, C-9, C-12, and C-21) via the γ-gauche effect; (2) the chemical shift values (C-9, C-12, and C-21) reflect the orientation (α or ß) of the hydroxy moiety (C-14 or C-17); (3) a double-bond positional change in ring A (Δ(2) to Δ(3)), or hydroxylation (C-27), results in a minuscule effect on the chemical shifts of carbons in rings C and D (from C-12 to C-18); and (4) the (13)C NMR γ-gauche effect method is more convenient and reliable than the traditional approach ((1)H NMR shift comparisons in C5D5N versus CDCl3) to probe the orientation of the hydroxy substituent (C-14 and C-17). Utilization of these rules demonstrated that the reported (13)C NMR data of withanolides 1a-29a were inconsistent with their published structures, which were subsequently revised as 1-16 and 12 and 18-29, respectively. When combined, this strongly supports the application of these methods to determine the relative configuration of steroidal substituents.
Asunto(s)
Witanólidos/química , Modelos Moleculares , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Esteroides/químicaRESUMEN
Previously, we have shown that downregulation of POLD4 in lung cancer cells delays progression through the G1-S cell cycle transition and leads to increased genomic instability. To date however, detailed molecular mechanisms have not been elucidated to explain how this occurs. In the present study, we found that reduction in POLD4 by siRNA knockdown promoted downregulation of both p-Akt Ser473 and Skp2 as well as upregulation of p27. Furthermore, these protein expression levels were rescued when siRNA-resistant POLD4 was ectopically expressed in the knockdown cells. These data suggest that the POLD4 downregulation is associated with impaired Akt-Skp2-p27 pathway in lung cancer.
Asunto(s)
Inhibidor p27 de las Quinasas Dependientes de la Ciclina/antagonistas & inhibidores , ADN Polimerasa III/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , ARN Interferente Pequeño/farmacología , Proteínas Quinasas Asociadas a Fase-S/antagonistas & inhibidores , Línea Celular Tumoral , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , ADN Polimerasa III/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo/efectos de los fármacos , Fase G1/efectos de los fármacos , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fase S/efectos de los fármacos , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Relación Estructura-ActividadRESUMEN
Nine new withanolides (1-9), withahisolides A-I, were isolated along with nine known compounds (10-18) from the aerial parts of Physalis hispida. The structures of 1-9 were elucidated through a variety of spectroscopic techniques, while the structures of 1 and 2 were confirmed by X-ray crystallographic analysis. Compounds 1-3 are the first withanolides with nonaromatic six-membered ring D moieties. In addition, withanolide 8 represents a novel withanolide skeleton due to the absence of a C-13-C-17 bond within the steroidal nucleus.
Asunto(s)
Physalis/química , Witanólidos/aislamiento & purificación , Cristalografía por Rayos X , Kansas , Conformación Molecular , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Witanólidos/químicaRESUMEN
BACKGROUND: Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with poor prognosis, as a majority of patients present with advanced disease. Current adjuvant strategies for metastatic patients include mitotane or other cytotoxic agents and carry a significant morbidity as well as a low (<10 %) 5-year survival. Withanolides, including withaferin A, are novel chemotherapeutic agents with potent targeted effects in medullary thyroid cancer and a number of solid malignancies with low toxicity in vivo. We hypothesize that novel naturally derived withanolides will have potent targeted anti-cancer activity against ACCs. METHODS: In vitro cell viability of ACC cell lines (Y1 and SW13) was measured using MTS cell proliferation assay. Cell cycle and apoptotic analysis studied using annexin V/propidium iodide staining on flow cytometry (FC) and targeted molecular mechanisms of withanolide cytotoxicity were assessed using standard Western blot analysis. RESULTS: All the withanolides potently reduced ACC cell viability on MTS assay with 7- to 185-fold higher selectivity than normal fibroblasts. Cell cycle analysis demonstrated a shift in cell cycle arrest from G1/G0 to G2/M with induction of apoptosis at nanomolar concentrations of withanolides. Unlike current ACC therapeutics, withanolides modulated expression of several key oncogenic pathway proteins in ACCs by Western blot, including Jagged 1, MAPK, and Akt/mTOR pathway proteins in a dose-dependent manner after 24 h drug treatment of SW13 cells. CONCLUSION: These results demonstrate the first evidence of the anticancer efficacy of withanolides in ACC cells and provide support for future translational evaluation of these compounds as novel therapeutic agents for ACC patients.