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1.
Materials (Basel) ; 17(6)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38541512

RESUMEN

Coke plays a key role as the skeleton of the charge column in BF. The gas path formed by the coke layer in the BF has a decisive influence on gas permeability. At high temperatures, the interface between coke and ore undergoes a melting reaction of coke and a reduction reaction of ore. The better the reducibility of the ore, the more conducive it is to the coupling reaction of ore and coke. The melting loss reaction of coke becomes more intense, and the corresponding strength of coke will decrease, which will affect the permeability of the blast furnace and is not conducive to the smooth operation of the blast furnace. Especially with a deterioration in iron ore quality, BF operation faces severe challenges, which makes it necessary to find an effective way to strengthen BF operation. In this study, a melting-dropping furnace was used to develop and clarify the high-temperature interaction between coke and iron ores with different layer thicknesses. The influencing factors were studied by establishing a gas permeability mathematical model and observing the metallographic microscope images of samples after the coke solution loss reaction. The relationships between coke layer thickness, distribution of gas flow, and pressure drop were obtained. The results showed that, under certain conditions, the gas permeability property of a furnace burden has been improved after the coke layer thickness increased. Upon observing the size of coke particles at the interface reaction site, the degree of melting loss reaction can be determined. A smaller particle size indicates more melting loss reaction. A dripping eigenvalue for molten metal was introduced to evaluate the dynamic changes in the comprehensive dripping properties of molten metal of furnace burden, which showed that the dripping eigenvalue for the molten metal could deteriorate because of the unruly thickness and the coke layer thickness should be limited through considering the operational indicators of the blast furnace.

2.
Phytomedicine ; 127: 155453, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38452692

RESUMEN

BACKGROUND: Herpes zoster (HZ) is a common medical condition accompanied by several distressing symptoms, including acute pain. Pien Tze Huang (PZH) is a well-known traditional Chinese medicine (TCM) with numerous pharmacological effects, including antiviral properties, neuroprotection, and immunity regulation. PURPOSE: To investigate the efficacy and safety of PZH capsules in patients with HZ. STUDY DESIGN: A multicenter, double-blinded, randomized, and placebo-controlled trial from 8 hospitals in 5 cities of China. METHODS: Eligible participants were randomly assigned to the PZH capsule and placebo group at a 1:1 ratio. Treatment was conducted for 14 days with a window period of no more than 2 days. For the first 7 days, participants received antiviral drugs combined with PZH capsules (0.6 g/time, 3 times a day) or placebos. For the remaining 7 days, they were only treated with PZH capsules (0.6 g/time, 3 times a day) or placebos. RESULTS: We included 222 patients in the full analysis set (FAS), and 187 patients in the per protocol set (PPS). The change of numeric rating scale pain scores from baseline to the seventh day (±1 day) after treatment in the PZH capsule group was statistically superior to the placebo group (FAS: 2.33 vs. 1.71, 97.5%CI: 0.03 ∼ 1.19; PPS: 2.29 vs. 1.51, 97.5%CI: 0.18 ∼ 1.38). In the PPS, there was a significant difference in the time (days) of pain relief between the placebo group and the PZH capsule group (Mean (SD): 5.71 (3.76) vs. 4.69 (3.57), p = 0.046). On the seventh day (±1 day) after treatment, the level of CD8+ cells in the PZH capsule group were higher than those of the placebo group (FAS: Mean (SD): 24.08 (6.81) vs. 21.93 (8.19), p = 0.007; PPS: Mean (SD): 24.26 (6.93) vs. 22.15 (8.51), p = 0.012). The level of cytotoxic lymphocyte cells found similar results on the seventh day (±1 day) (FAS: Mean (SD): 12.17 (4.65) vs. 10.55 (4.15), p = 0.018; PPS: Mean (SD): 12.25 (4.65) vs. 10.11 (3.93), p = 0.002). No serious adverse events were noted and PZH capsules were well tolerated. CONCLUSION: PZH capsules confer therapeutic effects on HZ with the TCM symptom of stagnated heat of liver channel by substantially reducing the pain intensity, shortening the time of pain relief as well as regulating the immune function. On the basis of the efficacy and safety profiles, PZH capsules may be a promising complementary therapy for the treatment of HZ.


Asunto(s)
Medicamentos Herbarios Chinos , Herpes Zóster , Humanos , Medicamentos Herbarios Chinos/efectos adversos , Medicina Tradicional China , Herpes Zóster/tratamiento farmacológico , Dolor/tratamiento farmacológico
3.
Environ Pollut ; 344: 123312, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38199480

RESUMEN

Unveiling composition and release rates of chemicals in chemical-intensive products (CIPs) such as inkjet fabrics that are applied extensively in advertising and publicizing industries, is of importance to sound management of chemicals. This study tentatively identified 212 compounds from 69 inkjet fabric samples using gas chromatograph coupled with quadrupole time-of-flight mass spectrometry (GC-QTOF-MS). Contents of six phthalate esters (PAEs) were quantified to range from 3.0 × 102 mg/kg to 3.1 × 105 mg/kg with GC-MS. Bis(2-ethylhexyl) phthalate was predominantly detected to average 96 g/kg. The inkjet fabrics collected from southern China contained fewer non-intentionally added substances (NIASs) than from northern China. Annual mass release rates (RM) of the 6 PAEs from inkjet fabrics to air were estimated to range from 1.4 × 10-2 kg/year to 2.8 × 104 kg/year in China in 2020, and the mean indoor RM was comparable with the outdoor one. Equilibrium partition coefficients of the compounds between the product and air, ambient temperature, and concentrations of chemicals in the product, are key factors leading to RM with the high variance. The findings indicate that contents of the NIASs in the CIPs should be minimized, and the refining concept should be adopted in design of the CIPs, so as to control the release of chemicals from the CIPs.


Asunto(s)
Ésteres , Ácidos Ftálicos , Ésteres/análisis , Ácidos Ftálicos/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , China
4.
BMC Microbiol ; 23(1): 237, 2023 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-37641037

RESUMEN

BACKGROUND: Despite the growing interest in the impact of the gut microbiome on cancer, the relationship between the lung microbiome and lung cancer has received limited investigation. Additionally, the composition of the oral microbiome was found to differ from that of individuals with lung cancer, indicating that these microorganisms may serve as potential biomarkers for the detection of lung cancer. METHODS: Forty-three Chinese lung cancer patients were enrolled in the current retrospective study and 16 S rRNA sequencing was performed on saliva, cancerous tissue (CT) and paracancerous tissue (PT) samples. RESULTS: Diversity and species richness were significantly different between the oral and lung microbiota. Lung microbiota were largely composed of the phyla Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. The relative abundance of Promicromonosporacea and Chloroflexi increased in CT, while Enterococcaceae and Enterococcus were enriched in PT (p<0.05). A cancer-related microbiota model was constructed and produced an area under the curve of 0.74 in the training set, indicating discrimination between subjects with and without cancer. CONCLUSIONS: Characterization of microbiota in saliva, CT and PT from Chinese lung cancer patients revealed little difference between CT and PT, indicating that the tumor and its microenvironment might influence the local microbiome. A model to distinguish between CT and PT was constructed, which has the potential to enhance our comprehension of the involvement of microbiota in the pathogenesis of lung cancer and identify novel therapeutic targets.


Asunto(s)
Neoplasias Pulmonares , Microbiota , Humanos , Saliva , Pueblos del Este de Asia , Estudios Retrospectivos , Microbiota/genética , Microambiente Tumoral
5.
J Recept Signal Transduct Res ; 42(1): 23-33, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33243063

RESUMEN

PURPOSE: Pulsatilla saponins from pulsatilla chinensis (Bunge) Regel have potential anti-tumor activities to certain human cancers. However, the roles of pulsatilla saponin E separated from pulsatilla saponins in non-small cell lung cancer (NSCLC) have not been reported. MATERIALS AND METHODS: After treating NSCLC cells by pulsatilla saponin E at different concentrations, cell viability was measured by MTT and CCK-8 assays, and cell migration, invasion and apoptosis were detected by scratch wound-healing, transwell and flow cytometry assays. The contents of free cholesterol (FC) and total cholesterol (TC) were measured by high performance liquid chromatography (HPLC). The expression levels of flotillin-1, flotillin-2, Akt, fatty acid synthase (FASN) were detected by qRT-PCR and Western blot assays. RESULTS: Pulsatilla saponin E suppressed viability, migration, invasion and promoted apoptosis of NSCLC cells followed by regulation of apoptosis-related proteins, reduced contents of FC and TC, and the expression levels of flotillin-1, flotillin-2, Akt, and FASN in a concentration-dependent manner. However, the inhibitory effects of pulsatilla saponin E on viability, migration, invasion of A549 cells and the expression levels of flotillin-1, flotillin-2, Akt, and FASN were reversed by flotillin-2 overexpression. CONCLUSIONS: Our study revealed that pulsatilla saponin E suppressed migration, invasion and promoted apoptosis of NSCLC cells through negatively regulating Akt/FASN signaling pathway via the inhibition of flotillin-2 in lipid raft (LR). The current findings could be explored for developing a novel therapeutic drug for NSCLC treatment.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Pulsatilla , Saponinas , Apoptosis , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Acido Graso Sintasa Tipo I , Ácido Graso Sintasas , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Microdominios de Membrana/metabolismo , Proteínas de la Membrana , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pulsatilla/metabolismo , Saponinas/farmacología
6.
J Hazard Mater ; 422: 126848, 2022 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-34403943

RESUMEN

Face masks are necessary for fighting against the coronavirus disease 2019 around the world. As the face mask is usually made from polymers and phthalates are widely-used additives into the polymers, the face mask could be a potential source of phthalate exposure to humans. However, limited knowledge is available on the occurrence and risks of the phthalates from the face mask. In this study, twelve phthalates were determined in 56 mask samples collected from different countries. The phthalates were detected in all the samples with total levels ranging from 115 ng/g to 37,700 ng/g. Estimated daily intakes (EDIs) of the phthalates from the masks ranged from 3.71 to 639 ng/kg-bw/day, and the EDIs of the phthalates from masks for toddlers were approximately 4-5 times higher than those for adults. Non-carcinogenic risks in relation to the phthalates in masks were found to be within safe levels, yet 89.3% of the mask samples exhibited potential carcinogenic effects to humans. The extent of the risks for wearing masks located at a moderate level comparing with other skin-contacted products. This study unveiled a potential source of phthalate exposure to human, and indicated necessity of managing types and levels of additives in the face masks.


Asunto(s)
COVID-19 , Ácidos Ftálicos , Adulto , Humanos , Máscaras , Ácidos Ftálicos/toxicidad , SARS-CoV-2
7.
Environ Sci Technol ; 55(17): 11874-11884, 2021 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-34488350

RESUMEN

Benzotriazole ultraviolet stabilizers (BUVSs) are high-production-volume chemicals with ubiquitous occurrence in the aquatic environment. However, little is known about their bioconcentration and biotransformation, and physiologically based toxicokinetic (PBTK) models for BUVSs are lacking. This study selected six BUVSs for which experiments were performed with zebrafish (Danio rerio) exposed to two different levels (0.5 and 10 µg·L-1). Higher kinetic bioconcentration factors (BCFs) were observed at the lower exposure level with environmental relevance, with BCF of 3.33 × 103 L·kg-1 for 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327). This phenomenon was interpreted by a nonlinear adsorption mechanism, where binding with specific protein sites contributes to bioconcentration. Muscle exhibited the lowest accumulation, in which depuration half-life of UV-327 was 19.5 d. In kidney, muscle, ovary, gill, and skin, logBCF increased with increase in log KOW of the BUVSs until log KOW was ca. 6.5, above which logBCF decreased. However, the trend was not observed in the liver and intestine. Six biotransformation products were identified and mainly accumulated in the liver and intestine. Considering the nonlinear adsorption mechanism in the PBTK model, the prediction accuracy of the model was improved, highlighting the binding of xenobiotics with specific protein sites in assessing the bioconcentration of chemicals for their risk assessment.


Asunto(s)
Contaminantes Químicos del Agua , Pez Cebra , Animales , Biotransformación , Femenino , Toxicocinética , Triazoles , Rayos Ultravioleta
8.
Front Immunol ; 12: 656817, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33912184

RESUMEN

Mice with a mutation at the LAT-PLCγ1 binding site (Y136) have a defect in thymocyte development due to dampened TCR signaling. CD4+ T cells that do reach the periphery are hyper-activated and skewed to Th2. Over time, these mice develop an autoimmune-like syndrome, characterize by overproduction of Th2 cytokines, T cell infiltration into various organs, and B cell activation, isotype switching, and autoantibody production. In this study, we examined IL4 production by CD4+ T cells in the LATY136F mice using the KN2 reporter mice, in which human CD2 expression marks T cells that are actively producing IL4 protein. We showed that these mice had spontaneous Tfh differentiation. Despite the fact that the majority of CD4+ T cells were skewed to Th2 and were GATA3+, only a small subset of them were actively secreting IL4. These T cells were Tfh cells that expressed BCL6 and were localized to B cell-rich germinal centers within the spleen. Interestingly, these Tfh cells expressed high levels of both BCL6 and GATA3. By using LAT conditional knockout mice that inducibly express only the LATY136F allele, we further showed that Tfh cell differentiation was likely the result of defective LAT-PLCγ1 signaling in the periphery. In addition, B cells were required for spontaneous development of Tfh cells and uncontrolled T cell expansion in these mice. Together, these results indicated a novel role for tonic LAT-PLCγ1 signaling in modulating Tfh cell differentiation during development of autoimmune syndrome.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Alelos , Sustitución de Aminoácidos , Diferenciación Celular/genética , Proteínas de la Membrana/genética , Células T Auxiliares Foliculares/citología , Células T Auxiliares Foliculares/metabolismo , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Comunicación Celular/inmunología , Diferenciación Celular/inmunología , Centro Germinal/citología , Centro Germinal/inmunología , Inmunofenotipificación , Proteína Coestimuladora de Linfocitos T Inducibles/genética , Proteína Coestimuladora de Linfocitos T Inducibles/metabolismo , Interleucina-4/biosíntesis , Ratones , Ratones Noqueados , Transducción de Señal , Células T Auxiliares Foliculares/inmunología
10.
Transplantation ; 105(12): 2554-2563, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33724247

RESUMEN

BACKGROUND: Immunological mechanisms linking undernutrition to infection and the alloimmune response are poorly understood in transplantation. We aimed to determine how undernutrition and hypoleptinemia impact T-cell allospecific and cytomegalovirus (CMV) viral-specific immunity in a murine model. METHODS: Fed, fasted for 48 h (model of undernutrition), and fasted with leptin injections (leptin rescue), C57BL/6 mice received skin grafts from either C57BL/6 (syngeneic) or BALB/c (allogeneic) mice donors. Allograft rejection and survival were monitored. Fed, fasted, and leptin rescue C57BL/6 mice were inoculated with murine cytomegalovirus (mCMV). Mouse spleens were retrieved for T-cell flow cytometry analysis, mCMV DNA extraction, and quantitative polymerase chain reaction. Serum leptin levels were measured with ELISA. RESULTS: Fasted mice had prolonged rejection-free and graft survival compared with fed mice (P = 0.0002 and P = 0.043). Leptin administration did not alter rejection-free survival or allograft failure. CD8+ central memory T cell and CD8+ effector T cell proportions were significantly lower in fasted mice receiving allogeneic skin transplants compared with fed mice (P = 0.0009 and P = 0.0015). Fasted mice had higher viral loads (P = 0.0028) and impaired mCMV-specific interferon-gamma-producing CD8+ T cells (P = 0.0007), which improved with leptin rescue (P = 0.032). CONCLUSIONS: Undernutrition and its associated hypoleptinemia correlated with impaired allospecific and viral-specific immunities. Leptin administration decreased mCMV viral burden and increased mCMV-specific T-cell immunity, however, it did not increase rejection or worsen graft survival in complete major histocompatibility complex-mismatched skin allografts. Leptin may be a potential adjunctive therapy for CMV viremia in undernourished transplant recipients.


Asunto(s)
Infecciones por Citomegalovirus , Desnutrición , Animales , Linfocitos T CD8-positivos , Citomegalovirus , Rechazo de Injerto/prevención & control , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL
11.
J Cereb Blood Flow Metab ; 41(5): 1091-1102, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32787543

RESUMEN

In patients who are successfully resuscitated after initial cardiac arrest (CA), mortality and morbidity rates are high, due to ischemia/reperfusion injury to the whole body including the nervous and immune systems. How the interactions between these two critical systems contribute to post-CA outcome remains largely unknown. Using a mouse model of CA and cardiopulmonary resuscitation (CA/CPR), we demonstrate that CA/CPR induced neuroinflammation in the brain, in particular, a marked increase in pro-inflammatory cytokines, which subsequently activated the hypothalamic-pituitary-adrenal (HPA) axis. Importantly, this activation was associated with a severe immunosuppression phenotype after CA. The phenotype was characterized by a striking reduction in size of lymphoid organs accompanied by a massive loss of immune cells and reduced immune function of splenic lymphocytes. The mechanistic link between post-CA immunosuppression and the HPA axis was substantiated, as we discovered that glucocorticoid treatment, which mimics effects of the activated HPA axis, exacerbated post-CA immunosuppression, while RU486 treatment, which suppresses its effects, significantly mitigated lymphopenia and lymphoid organ atrophy and improved CA outcome. Taken together, targeting the HPA axis could be a viable immunomodulatory therapeutic to preserve immune homeostasis after CA/CPR and thus improve prognosis of post-resuscitation CA patients.


Asunto(s)
Reanimación Cardiopulmonar/efectos adversos , Paro Cardíaco/terapia , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Mifepristona/farmacología , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Animales , Encéfalo/metabolismo , Encéfalo/fisiopatología , Reanimación Cardiopulmonar/métodos , Estudios de Casos y Controles , Citocinas/metabolismo , Glucocorticoides/administración & dosificación , Glucocorticoides/farmacología , Paro Cardíaco/complicaciones , Paro Cardíaco/patología , Homeostasis/efectos de los fármacos , Antagonistas de Hormonas/administración & dosificación , Antagonistas de Hormonas/farmacología , Sistema Hipotálamo-Hipofisario/inmunología , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipotálamo-Hipofisario/fisiopatología , Terapia de Inmunosupresión/efectos adversos , Masculino , Ratones , Ratones Endogámicos C57BL , Mifepristona/administración & dosificación , Modelos Animales , Sistema Hipófiso-Suprarrenal/inmunología , Sistema Hipófiso-Suprarrenal/metabolismo , Sistema Hipófiso-Suprarrenal/fisiopatología , Pronóstico , Daño por Reperfusión
12.
Heart Surg Forum ; 23(6): E725-E730, 2020 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-33234221

RESUMEN

BACKGROUND: To verify the validity and feasibility of using a mechanical compression method to locate the atrioventricular node in open-heart surgery. METHODS: Ten healthy miniature pigs were used to establish an animal model of the beating heart under cardiopulmonary bypass. During the operation, the atrioventricular node and its surrounding areas were stimulated by mechanical compression (mechanical compression method), and the occurrence of complete atrioventricular block was judged by real-time electrocardiograph monitoring and direct observation of the heart rhythm to identify the position of the atrioventricular node. The final localization of the atrioventricular node was determined using the iodine staining method, and the results were used as the "gold standard" to test the effectiveness and feasibility of the mechanical compression method for locating the atrioventricular node. RESULTS: With the beating heart model, complete atrioventricular block occurred after mechanical compression of the "atrioventricular node" area in 10 pigs. Nine pigs regained normal conduction immediately after the compression was released, and one pig failed to recover. No atrioventricular block or other arrhythmias occurred after mechanical compression of the "non-atrioventricular node" area. The sensitivity of the method was 86.6%, specificity was 100.0%, misdiagnosis rate was 0.0%, missed diagnosis rate was 13.4%, positive predictive value was 100.0%, negative predictive value was 97.9%, positive likelihood ratios were +∞, negative likelihood ratios were 13.4%, accuracy was 98.1%, and diagnostic odds ratio was +∞. CONCLUSION: This study innovatively proposes the application of the mechanical compression method to locate the atrioventricular node during operation and preliminarily proves that this method is effective and feasible through animal experiments.


Asunto(s)
Bloqueo Atrioventricular/diagnóstico , Nodo Atrioventricular/fisiopatología , Procedimientos Quirúrgicos Cardíacos , Complicaciones Posoperatorias , Animales , Bloqueo Atrioventricular/etiología , Bloqueo Atrioventricular/fisiopatología , Modelos Animales de Enfermedad , Electrocardiografía/métodos , Porcinos , Porcinos Enanos
13.
Environ Sci Technol ; 54(20): 13175-13185, 2020 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-32985863

RESUMEN

Extensive application of antibiotics leads to their ubiquitous occurrence in coastal aquatic environments. However, it remains largely unknown whether antibiotics can be bioaccumulated and biotransformed in major mariculture organisms such as sea cucumbers and toxicokinetic models for Echinodermata are lacking. In this study, laboratory exposure experiments on juvenile sea cucumber (Apostichopus japonicus) were performed for seven antibiotics (sulfadiazine, sulfamethoxazole, trimethoprim, enrofloxacin, ofloxacin, clarithromycin, and azithromycin). Field sea cucumber and surrounding seawater samples were also analyzed. Results show that the sea cucumbers tend to accumulate high concentrations of the antibiotics with kinetic bioconcentration factors (BCFs) up to 1719.7 L·kg-1 for ofloxacin. The BCFs determined in the laboratory agree well with those estimated from the field measurements. Seven biotransformation products (BTPs) of the antibiotics were identified, four of which were not reported previously in aquatic organisms. The BTPs were mainly found in the digestive tract, indicating its high capacity in the biotransformation. A multicompartmental toxicokinetic model based on the principles of passive diffusion was developed, which can successfully predict time-course concentrations of the antibiotics in different compartments of the juvenile sea cucumbers. The findings may offer a scientific basis for assessing health risks and guiding healthy mariculture of sea cucumbers.


Asunto(s)
Pepinos de Mar , Stichopus , Animales , Antibacterianos/toxicidad , Bioacumulación , Biotransformación , Toxicocinética
14.
Sci Rep ; 10(1): 11860, 2020 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-32681076

RESUMEN

The cellular mechanisms underlying impaired function of aged liver grafts have not been fully elucidated, but mitochondrial dysfunction appears to be contributory. Sirtuin1 has been identified as a key mediator of mitochondrial recovery following ischemia-reperfusion injury. The purpose of this study was to determine whether differences exist in sirtuin-1 expression/activity in old vs. young liver grafts and to determine correlations with mitochondrial function, graft metabolic function, and graft injury. Old and young rat liver grafts (N = 7 per group) were exposed to 12 h of static cold storage (SCS), followed by a 2 h period of graft reperfusion ex vivo. Sirtuin1 expression and activity, mitochondrial function, graft metabolic function, and graft injury were compared. Sirtuin1 expression is upregulated in young, but not old, liver grafts in response to cold storage and reperfusion. This is associated with diminished tissue ATP, antioxidant defense, and graft metabolic function in old liver grafts. There was no evidence of increased inflammation or histologic injury in old grafts. Sirtuin1 expression is diminished in old liver grafts and correlates with mitochondrial and metabolic function. The sirtuin pathway may represent a target for intervention to enhance the function of aged liver grafts.


Asunto(s)
Activación Enzimática , Expresión Génica , Trasplante de Hígado , Hígado/metabolismo , Preservación de Órganos , Sirtuina 1/genética , Sirtuina 1/metabolismo , Animales , Antioxidantes/metabolismo , Biomarcadores , Criopreservación , Citocinas/metabolismo , Supervivencia de Injerto , Mediadores de Inflamación/metabolismo , Pruebas de Función Hepática , Masculino , Mitocondrias/metabolismo , Modelos Animales , Consumo de Oxígeno , Ratas , Daño por Reperfusión , Factores de Tiempo
15.
Nature ; 580(7803): E8, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32296176

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

16.
Nature ; 579(7800): 534-539, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32214267

RESUMEN

The broad applications of ultrawide-band signals and terahertz waves in quantum measurements1,2, imaging and sensing techniques3,4, advanced biological treatments5, and very-high-data-rate communications6 have drawn extensive attention to ultrafast electronics. In such applications, high-speed operation of electronic switches is challenging, especially when high-amplitude output signals are required7. For instance, although field-effect and bipolar junction devices have good controllability and robust performance, their relatively large output capacitance with respect to their ON-state current substantially limits their switching speed8. Here we demonstrate a novel on-chip, all-electronic device based on a nanoscale plasma (nanoplasma) that enables picosecond switching of electric signals with a wide range of power levels. The very high electric field in the small volume of the nanoplasma leads to ultrafast electron transfer, resulting in extremely short time responses. We achieved an ultrafast switching speed, higher than 10 volts per picosecond, which is about two orders of magnitude larger than that of field-effect transistors and more than ten times faster than that of conventional electronic switches. We measured extremely short rise times down to five picoseconds, which were limited by the employed measurement set-up. By integrating these devices with dipole antennas, high-power terahertz signals with a power-frequency trade-off of 600 milliwatts terahertz squared were emitted, much greater than that achieved by the state of the art in compact solid-state electronics. The ease of integration and the compactness of the nanoplasma switches could enable their implementation in several fields, such as imaging, sensing, communications and biomedical applications.

17.
Nature ; 578(7796): 577-581, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32076270

RESUMEN

Hydrogen peroxide (H2O2) is a major reactive oxygen species in unicellular and multicellular organisms, and is produced extracellularly in response to external stresses and internal cues1-4. H2O2 enters cells through aquaporin membrane proteins and covalently modifies cytoplasmic proteins to regulate signalling and cellular processes. However, whether sensors for H2O2 also exist on the cell surface remains unknown. In plant cells, H2O2 triggers an influx of Ca2+ ions, which is thought to be involved in H2O2 sensing and signalling. Here, by using forward genetic screens based on Ca2+ imaging, we isolated hydrogen-peroxide-induced Ca2+ increases (hpca) mutants in Arabidopsis, and identified HPCA1 as a leucine-rich-repeat receptor kinase belonging to a previously uncharacterized subfamily that features two extra pairs of cysteine residues in the extracellular domain. HPCA1 is localized to the plasma membrane and is activated by H2O2 via covalent modification of extracellular cysteine residues, which leads to autophosphorylation of HPCA1. HPCA1 mediates H2O2-induced activation of Ca2+ channels in guard cells and is required for stomatal closure. Our findings help to identify how the perception of extracellular H2O2 is integrated with responses to various external stresses and internal cues in plants, and have implications for the design of crops with enhanced fitness.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Peróxido de Hidrógeno/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Calcio/metabolismo , Canales de Calcio/metabolismo , Señalización del Calcio , Cisteína/química , Cisteína/metabolismo , Activación Enzimática , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Mutación , Oxidación-Reducción , Células Vegetales/metabolismo , Dominios Proteicos , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/genética
18.
J Surg Res ; 249: 50-57, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31918330

RESUMEN

BACKGROUND: Immunosuppressive medications are widely used for the prevention of allograft rejection in transplantation and graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. Despite their clinical utility, these medications are accompanied by multiple off-target effects, some of which may be mediated by their effects on mitochondria. METHODS: We examined the effect of commonly used immunosuppressive reagents, mycophenolate mofetil (MMF), cyclosporine A (CsA), rapamycin, and tacrolimus on mitochondrial function in human T-cells. T-cells were cultured in the presence of immunosuppressive medications in a range of therapeutic doses. After incubation, mitochondrial membrane potential, reactive oxygen species (ROS) production, and apoptotic cell death were measured by flow cytometry after staining with DiOC6, MitoSOX Red, and Annexin V and 7-AAD, respectively. Increases in cytosolic cytochrome c were demonstrated by Western blot. T-cell basal oxygen consumption rates were measured using a Seahorse bioanalyzer. RESULTS: T-cells demonstrated significant levels of mitochondrial depolarization after treatment with therapeutic levels of MMF but not after treatment with CsA, tacrolimus, or rapamycin. Only MMF induced T-cell ROS production and induced significant levels of apoptotic cell death that were associated with increased levels of cytosolic cytochrome c. MMF decreased T-cell basal oxygen consumption within its therapeutic range, and CsA demonstrated a trend toward this result. CONCLUSIONS: The impairment of mitochondrial function by commonly used immunosuppressive reagents may impair T-cell differentiation and function by decreasing energy production, producing toxic ROS, and inducing apoptotic cell death.


Asunto(s)
Inmunosupresores/efectos adversos , Mitocondrias/efectos de los fármacos , Linfocitos T/efectos de los fármacos , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Ciclosporina/efectos adversos , Metabolismo Energético/efectos de los fármacos , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Células Jurkat , Potencial de la Membrana Mitocondrial , Mitocondrias/patología , Ácido Micofenólico/efectos adversos , Especies Reactivas de Oxígeno/metabolismo , Sirolimus/efectos adversos , Linfocitos T/citología , Linfocitos T/patología , Tacrolimus/efectos adversos
19.
Invest New Drugs ; 38(2): 350-359, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31124054

RESUMEN

Intrinsic chemoresistance is the main reason for the failure of human pancreatic ductal adenocarcinoma (PDAC) therapy. To identify the candidate protein, we compared the protein expression profiling of PDAC cells and its distinct surviving cells following primary treatment with gemcitabine (GEM) and 5-fluorouracil (5-FU) by two-dimensional electrophoresis combined with liquid chromatography-mass spectrometry or mass spectrometry. A total of 20 differentially expressed proteins were identified, and annexin A1 (ANXA1) was analyzed for further validation. The functional validation showed that the downregulation of ANXA1 contributes to GEM and 5-FU resistance in PDAC cells through protein kinase C/c-Jun N-terminal kinase/P-glycoprotein signaling pathway. Our findings provide a platform for the further elucidation of the underlying mechanisms of PDAC intrinsic chemoresistance and demonstrated that ANXA1 may be a valid marker for anticancer drug development.


Asunto(s)
Anexina A1 , Biomarcadores de Tumor , Desoxicitidina/análogos & derivados , Resistencia a Antineoplásicos , Fluorouracilo/uso terapéutico , Neoplasias Pancreáticas , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Anexina A1/genética , Anexina A1/metabolismo , Antimetabolitos Antineoplásicos/farmacología , Antimetabolitos Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Desoxicitidina/farmacología , Desoxicitidina/uso terapéutico , Regulación hacia Abajo , Femenino , Fluorouracilo/farmacología , Humanos , MAP Quinasa Quinasa 4/metabolismo , Masculino , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Proteína Quinasa C/metabolismo , Transducción de Señal , Gemcitabina
20.
Sci Total Environ ; 703: 135562, 2020 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-31767303

RESUMEN

Plant-soil systems have complex regulatory mechanisms for xenobiotics uptake by plant, and these chemicals in soil pore water (SPW) are regarded as the bioavailable fraction. To date, little is known about the role of SPW in regard to the bioavailability of antibiotics for plant. In this study, in situ soil moisture sampler (SMS) was adopted to collect SPW from four paddy soils without disrupting the rhizosphere zone to evaluate antibiotic uptake in rice. The results show that SMS is applicable for antibiotics that have small molecular sizes and Log Kow values, e.g., sulfadiazine (SDZ), sulfamethoxazole (SMZ), trimethoprim (TRM), and florfenicol (FLR). However, SMS performance was not feasible for large size and medium hydrophobic clarithromycin (CLR). Antibiotics in SPW demonstrated differences among chemicals and soils. Relatively higher levels of SDZ, SMZ, and FLR were observed in SPW than TRM, and neutral Panjin soil had the highest levels of antibiotics in SPW among four soils. The levels of antibiotics in SPW were negatively correlated with their soil partition parameter, Kd. Rapid decreases of SMZ, FLR, and SDZ in the SPW were consistent with their low residues in the final soils. All antibiotics were detectable in rice roots, followed by low detection levels in a few shoot samples, while no antibiotics were detectable in the grains of four soils. Relatively higher levels of SDZ, SMZ and FLR were observed in the roots of Panjin soil, consistent with their levels in SPW and Kd values. Furthermore, CLR and TRM were observed to have higher levels in roots, which was regarded as a consequence of their relatively longer persistence. Our study indicates that SMS is an applicable technique for in situ sampling of SPW, and level of antibiotics in SPW can work as a useful indicator to explore their bioavailability to plants.


Asunto(s)
Antibacterianos/análisis , Monitoreo del Ambiente , Contaminantes del Suelo/análisis , Rizosfera , Suelo/química , Sulfametoxazol , Trimetoprim , Agua
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