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1.
Environ Sci Technol ; 58(20): 8643-8653, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38676641

RESUMEN

Antimicrobial nanomaterials frequently induce inflammatory reactions within lung tissues and prompt apoptosis in lung cells, yielding a paradox due to the inherent anti-inflammatory character of apoptosis. This paradox accentuates the elusive nature of the signaling cascade underlying nanoparticle (NP)-induced pulmonary inflammation. In this study, we unveil the pivotal role of nano-microflora interactions, serving as the crucial instigator in the signaling axis of NP-induced lung inflammation. Employing pulmonary microflora-deficient mice, we provide compelling evidence that a representative antimicrobial nanomaterial, silver (Ag) NPs, triggers substantial motility impairment, disrupts quorum sensing, and incites DNA leakage from pulmonary microflora. Subsequently, the liberated DNA molecules recruit caspase-1, precipitating the release of proinflammatory cytokines and activating N-terminal gasdermin D (GSDMD) to initiate pyroptosis in macrophages. This pyroptotic cascade culminates in the emergence of severe pulmonary inflammation. Our exploration establishes a comprehensive mechanistic axis that interlinks the antimicrobial activity of Ag NPs, perturbations in pulmonary microflora, bacterial DNA release, macrophage pyroptosis, and consequent lung inflammation, which helps to gain an in-depth understanding of the toxic effects triggered by environmental NPs.


Asunto(s)
Neumonía , Piroptosis , Piroptosis/efectos de los fármacos , Ratones , Animales , Neumonía/inducido químicamente , Neumonía/patología , Plata/toxicidad , Nanopartículas del Metal/toxicidad , Macrófagos/efectos de los fármacos , Inflamación
3.
Small ; 20(17): e2307728, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38263806

RESUMEN

Herein, the structure of integrated M3D inverters are successfully demonstrated where a chemical vapor deposition (CVD) synthesized monolayer WSe2 p-type nanosheet FET is vertically integrated on top of CVD synthesized monolayer MoS2 n-type film FET arrays (2.5 × 2.5 cm) by semiconductor industry techniques, such as transfer, e-beam evaporation (EBV), and plasma etching processes. A low temperature (below 250 °C) is employed to protect the WSe2 and MoS2 channel materials from thermal decomposition during the whole fabrication process. The MoS2 NMOS and WSe2 PMOS device fabricated show an on/off current ratio exceeding 106 and the integrated M3D inverters indicate an average voltage gain of ≈9 at VDD = 2 V. In addition, the integrated M3D inverter demonstrates an ultra-low power consumption of 0.112 nW at a VDD of 1 V. Statistical analysis of the fabricated inverters devices shows their high reliability, rendering them suitable for large-area applications. The successful demonstration of M3D inverters based on large-scale 2D monolayer TMDs indicate their high potential for advancing the application of 2D TMDs in future integrated circuits.

4.
Nat Commun ; 14(1): 3740, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37349341

RESUMEN

Polyhalogenated carbazoles (PHCZs) are emerging global pollutants found in environmental matrices, e.g., 3000 tonnes of PHCZs have been detected in the sediments of the Great Lakes. Recognition of PHCZ emissions from ongoing industrial activities worldwide is still lacking. Here, we identify and quantify PHCZ emissions from 13 large-scale industries, 12 of which previously have no data. Congener profiles of PHCZs from investigated industrial sources are clarified, which enables apportioning of PHCZ sources. Annual PHCZ emissions from major industries are estimated on the basis of derived emission factors and then mapped globally. Coke production is a prime PHCZ emitter of 9229 g/yr, followed by iron ore sintering with a PHCZ emission of 3237 g/yr. China, Australia, Japan, India, USA, and Russia are found to be significant emitters through these industrial activities. PHCZ pollution is potentially a global human health and environmental issue.


Asunto(s)
Carbazoles , Contaminantes Químicos del Agua , Humanos , Contaminantes Químicos del Agua/análisis , China , Contaminación Ambiental , Monitoreo del Ambiente
5.
Sci Total Environ ; 854: 158793, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36113794

RESUMEN

Emissions from two typical cement kilns co-processing different kind of hazardous waste were analyzed for 143 congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls, polychlorinated naphthalenes, polybrominated dibenzo-p-dioxins and dibenzofurans, and polybrominated diphenyl ethers. The congener distributions in different process stages were investigated. One of the plants co-processed waste chemical reagents from laboratories. The emission factor (TEQ basis) for the plant was 2.09 ng WHO2005 TEQ/t, with the kiln head and the kiln back end contributing 1.18, 0.91 ng WHO2005 TEQ/t, respectively. The other plant co-processed municipal waste incineration fly ash. The emission factor for the plant was 0.12 ng WHO2005 TEQ/t, with the kiln head and the kiln back end contributing 0.022, and 0.10 ng WHO2005 TEQ/t. These results indicate that co-processing of waste containing reagents from laboratories may lead to higher emission levels than co-processing of other types of waste. The congener patterns of persistent organic pollutants (POPs) in ash samples from the humidifier tower were similar to those in samples from the bag filter at the kiln back end. The correlation coefficients of five pollutants between the humidifier and bag filters samples were generally high, which indicated that conditions in those two stages similarly favored the formation of these POPs. Comparison of the concentrations for different process stages suggested that the main stage for formation of unintentional POPs was the humidifier tower. These results improve our understanding of emission characteristics and could be used for simultaneous control of multiple POPs.

6.
Front Microbiol ; 13: 1005818, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36225375

RESUMEN

This study aimed to determine the effect of capsicum oleoresin (CAP) on rumen fermentation and microbial abundance under different temperature and dietary conditions in vitro. The experimental design was arranged in a 2 × 2 × 3 factorial format together with two temperatures (normal: 39°C; hyperthermal: 42°C), two forage/concentrate ratios (30:70; 70:30), and two CAP concentrations in the incubation fluid at 20 and 200 mg/L with a control group. Regarding the fermentation characteristics, high temperature reduced short-chain fatty acids (SCFA) production except for molar percentages of butyrate while increasing acetate-to-propionate ratio and ammonia concentration. The diets increased total SCFA, propionate, and ammonia concentrations while decreasing acetate percentage and acetate-to-propionate ratio. CAP reduced acetate percentage and acetate-to-propionate ratio. Under hyperthermal condition, CAP could reduce acetate percentage and increase acetate-to-propionate ratio, lessening the negative effect of high heat on SCFA. Hyperthermal condition and diet altered the relative abundance of microbial abundance in cellulose-degrading bacteria. CAP showed little effect on the microbial abundance which only increased Butyrivibrio fibrisolvens. Thus, CAP could improve rumen fermentation under different conditions, with plasticity in response to the ramp of different temperature and dietary conditions, although hardly affecting rumen microbial abundance.

7.
J Hazard Mater ; 439: 129602, 2022 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-35870210

RESUMEN

Simultaneous determination of 58 congeners of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), brominated polycyclic aromatic hydrocarbons (Br-PAHs), and polybrominated diphenyl ethers (PBDEs) from multiple stages of industrial-scale secondary copper smelting plants was conducted with the aim of understanding their variations and control. In addition to the historical manufacture of PBDEs as brominated flame retardants, this study confirmed that PBDEs can be unintentionally produced and released from the secondary copper industry. The average mass emission factors of PBDD/Fs, PBDEs, and Br-PAHs from different sources were 10.0, 5.21 × 103, and 7.24 × 103 µg t-1, respectively. Therefore, the emission of brominated persistent organic pollutants (POPs) in the secondary copper industry should be of concern. The concentration of brominated POPs increased from the gas cooling stage to stack outlet due to the possible "memory effect" and the regenerated POPs were mainly low-brominated homologs. A comparison of brominated POPs with corresponding chlorinated analogs in the same process indicated that the formation pathway of Br-PAHs was consistent with that of chlorinated PAHs. However, unlike chlorinated dioxins and furans, PBDD/Fs can also be formed from PBDEs as precursors, leading to obvious increases in highly brominated furans. Therefore, inhibiting the unintentional formation of PBDEs is important for controlling brominated POPs emissions.


Asunto(s)
Dioxinas , Contaminantes Ambientales , Hidrocarburos Policíclicos Aromáticos , Cobre , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Furanos , Éteres Difenilos Halogenados/análisis
8.
Rapid Commun Mass Spectrom ; 36(14): e9324, 2022 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-35560965

RESUMEN

RATIONALE: Polyhalogenated carbazoles (PHCZs) are dioxin-like compounds that are ubiquitous in the environment. However, their unintentional emissions from industrial sources have received little attention and there is no method available for determination of PHCZs in industrial waste. This research develops a method for determination of PHCZs in industrial waste. METHODS: In this research, a glass column packed with activated silica serves as a rapid and efficient clean-up pretreatment for purification. An isotope dilution gas chromatography/triple quadrupole tandem mass spectrometry method was established for simultaneous determination of eleven PHCZs in industrial samples. RESULTS: The regression coefficients of the standard curves for the congeners were all >0.99. The method detection limit ranged from 1.46 to 3.82 ng/mL for liquid samples and from 0.009 to 0.021 ng/g for solid samples. The precision described by the relative standard deviation ranged from 2.4% to 18.4% for liquid samples and from 5.5% to 35.8% for solid samples. The recovery ranges for the liquid and solid samples were 82%-123% and 83%-137%, respectively. 3-Chlorocarbazole (3-CCZ) and 36-dichlorocarbazole (36-CCZ) can be detected in both chemical bottom liquid from vinyl chloride production and fly ash from medical waste incineration by this method. CONCLUSIONS: An efficient method is established for determination of PHCZs from industrial waste. The discovery of 3-CCZ and 36-CCZ highlights the importance of identification of potential industrial sources of PHCZs and clarification of their contribution to environmental risks. Our method could be applied to investigate industrial emission of PHCZs.


Asunto(s)
Residuos Industriales , Espectrometría de Masas en Tándem , Carbazoles/análisis , Carbazoles/química , Cromatografía de Gases y Espectrometría de Masas , Residuos Industriales/análisis
9.
Environ Sci Technol ; 56(9): 5520-5529, 2022 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-35417140

RESUMEN

Intake from food is considered an important route of human exposure to polychlorinated naphthalenes. To our knowledge, several studies have quantified dietary exposure but only in European countries and measuring only a few of the 75 congeners. In addition, the influence of source diversity on human exposure has seldom been assessed. We analyzed 192 composite food samples composed of 17,280 subsamples from 24 provinces in China to measure the concentrations of polychlorinated naphthalenes and estimate their daily intake and potential health risks on a national scale. The estimated cancer risk was in the range of 6.8 × 10-8 to 4.6 × 10-7. We compared our findings for 75 congeners with reports in the literature that quantified only 12 congeners. We estimate that these 12 congeners contribute only approximately 4% to the total mass daily intake of polychlorinated naphthalenes and 70% to the total toxic equivalent quantity, indicating underestimation of dietary exposure. The contributions of combustion-associated congeners to the total concentrations of polychlorinated naphthalenes were in the range of 31-52%, suggesting that the ongoing unintentional release of these compounds from industrial thermal processes is an important factor in polychlorinated naphthalene contamination and human exposure in China.


Asunto(s)
Exposición Dietética , Bifenilos Policlorados , China , Dibenzofuranos Policlorados , Monitoreo del Ambiente , Humanos , Industrias , Naftalenos/toxicidad
10.
J Hazard Mater ; 423(Pt A): 127080, 2022 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-34523503

RESUMEN

Thallium (Tl) is a trace metal with high toxicity. Comprehensive investigation of spatial distribution of Tl and microorganism is still limited in soils from mining area. In this study, 16S rRNA sequencing and network analysis were used for deciphering the co-occurrence patterns of bacterial communities in two different types of soil profiles around a typical Tl-bearing pyrite mine. The results showed that geochemical parameters (such as pH, S, Tl, Fe and TOM) were the driving forces for shaping the vertical distribution of microbial community. According to network analysis, a wide diversity of microbial modules were present in both soil profiles and affected by depth, significantly associated with variations in Tl geochemical fractionation. Phylogenetic information further unveiled that the microbial modules were mainly dominated by Fe reducing bacteria (FeRB), Fe oxidizing bacteria (FeOB), S oxidizing bacteria and Mn reducing bacteria. The results of metagenome indicated that Fe, Mn and S cycle in soil are closely involved in the biogeochemical cycle of Tl. The findings of co-occurrence patterns in the bacterial network and correlation between microorganisms and different geochemical fractions of Tl may benefit the strategy of bioremediation of Tl-contaminated soils with indigenous microbes.


Asunto(s)
Contaminantes del Suelo , Talio , Filogenia , ARN Ribosómico 16S/genética , Suelo , Contaminantes del Suelo/análisis , Talio/análisis
11.
Entropy (Basel) ; 23(8)2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-34441064

RESUMEN

A new active fault tolerant control scheme based on active fault diagnosis is proposed to address the component/actuator faults for systems with state and input constraints. Firstly, the active fault diagnosis is composed of diagnostic observers, constant auxiliary signals, and separation hyperplanes, all of which are designed offline. In online applications, only a single diagnostic observer is activated to achieve fault detection and isolation. Compared with the traditional multi-observer parallel diagnosis methods, such a design is beneficial to improve the diagnostic efficiency. Secondly, the active fault tolerant control is composed of outer fault tolerant control, inner fault tolerant control and a linear-programming-based interpolation control algorithm. The inner fault tolerant control is determined offline and satisfies the prescribed optimal control performance requirement. The outer fault tolerant control is used to enlarge the feasible region, and it needs to be determined online together with the interpolation optimization. In online applications, the updated state estimates trigger the adjustment of the interpolation algorithm, which in turn enables control reconfiguration by implicitly optimizing the dynamic convex combination of outer fault tolerant control and inner fault tolerant control. This control scheme contributes to further reducing the computational effort of traditional constrained predictive fault tolerant control methods. In addition, each pair of inner fault tolerant control and diagnostic observer is designed integratedly to suppress the robust interaction influences between estimation error and control error. The soft constraint method is further integrated to handle some cases that lead to constraint violations. The effectiveness of these designs is finally validated by a case study of a wastewater treatment plant model.

12.
Biosci Rep ; 41(4)2021 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-33835138

RESUMEN

OBJECTIVE: The present study aimed to identify risk factors for overall survival in advanced hepatocellular carcinoma (HCC) patients and establish a scoring system to select patients who would benefit from hepatic resection. METHODS: Survival curves were analyzed using the Kaplan-Meier method and log-rank test. The prognostic scoring system was developed from training cohort using a Cox-regression model and validated in a external validation cohort Results: There were 401 patients in the training cohort, 163 patients in the external validation cohorts. The training cohort median survival in all patients was 12 ± 1.07 months, rate of overall survival was 49.6% at 1 year, 25.0% at 3 years, and 18.0% at 5 years. A prognostic scoring system was established based on age, body mass index, alkaline phosphatase, tumor number and tumor capsule. Patients were classified as low- risk group(≤3.5) or high-risk group(>3.5). High-risk patients had a median survival of 9 months, compared with 23 months in low-risk patients. The area under the receiver operating characteristic curve (AUC) of the prognostic scoring system was 0.747 (0.694-0.801), which is significantly better than AFP, Child-Pugh and ALBI. The AUC of validation cohorts was 0.716 (0.63-0.803). CONCLUSION: A prognostic scoring system for hepatic resection in advanced HCC patients has been developed based entirely on preoperative variables. Patients classified as low risk using this system may experience better prognosis after hepatic resection.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Neoplasias Hepáticas/cirugía , Complicaciones Posoperatorias/epidemiología , Periodo Preoperatorio , Adolescente , Adulto , Factores de Edad , Anciano , Biomarcadores de Tumor/metabolismo , Índice de Masa Corporal , Carcinoma Hepatocelular/patología , Femenino , Hepatectomía/normas , Humanos , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Carga Tumoral
13.
Chemosphere ; 267: 128875, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33187660

RESUMEN

In this research, a novel iron based bimetallic nanoparticles (Fe-Ni) supported on activated carbon (AC) were synthesized and employed as an activator of persulfate in polycyclic aromatic hydrocarbons (PAHs) polluted sites remediation. AC-supported Fe-Ni activator was prepared according to two-step reduction method: the liquid phase reduction and H2- reduction under high temperature (600 °C), which was defined as Fe-Ni/AC. Characterizations using micropore physisorption analyzer, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HR-TEM) showed that the synthetic material had large specific surface area, nano-size and carbon-encapsulated metal particles, moreover, the lattice fringes of metals were clearly defined. The PAH compound types and their concentrations were determined by gas chromatography mass spectrometry (GC-MS) with SIM mode, the method detection limit (MDL) was estimated to about 0.21 µg/kg for PAHs, and the average recovery of PAHs was 96.3%. Mechanisms of PAH oxidation degradation with the reaction system of Fe-Ni/AC activated persulfate were discussed, the results showed that short-life free radicals, such as SO4-·, OH·, and OOH· were generated simultaneously, which acted as strong oxidizing radicals, resulting in the oxidation and almost complete opening of the PAH rings.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Carbón Orgánico , Hierro , Oxidación-Reducción , Hidrocarburos Policíclicos Aromáticos/análisis , Suelo , Contaminantes del Suelo/análisis , Sulfatos
14.
Biosci Rep ; 39(8)2019 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-31383787

RESUMEN

Aim: To explore clinical factors associated with extent of liver regeneration after hemihepatectomy to treat hepatocellular carcinoma (HCC).Methods: Future liver remnant volume (as a percentage of functional liver volume, %FLRV) and remnant liver volume were measured preoperatively and at 1, 5, 9, and 13 weeks postoperatively.Results: After hepatectomy, 1 of 125 patients (0.8%) died within 3 months, 13 (10.4%) experienced liver failure, and 99 (79.2%) experienced complications. %FLRV was able to predict liver failure with an area under the receiver operating characteristic curve of 0.900, and a cut-off value of 42.7% showed sensitivity of 85.7% and specificity of 88.6%. Postoperative median growth ratio was 21.3% at 1 week, 30.9% at 5 weeks, 34.6% at 9 weeks, and 37.1% at 13 weeks. Multivariate analysis identified three predictors associated with liver regeneration: FLRV < 601 cm3, %FLRV, and liver cirrhosis. At postoperative weeks (POWs) 1 and 5, liver function indicators were significantly better among patients showing high extent of regeneration than among those showing low extent, but these differences disappeared by POW 9.Conclusions: FLRV, %FLRV, and liver cirrhosis strongly influence extent of liver regeneration after hepatectomy. %FLRV values below 42.7% are associated with greater risk of post-hepatectomy liver failure.


Asunto(s)
Carcinoma Hepatocelular , Hepatectomía , Fallo Hepático , Neoplasias Hepáticas , Regeneración Hepática , Adulto , Anciano , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/fisiopatología , Carcinoma Hepatocelular/cirugía , Femenino , Estudios de Seguimiento , Humanos , Fallo Hepático/epidemiología , Fallo Hepático/etiología , Fallo Hepático/fisiopatología , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/fisiopatología , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad
15.
Am J Surg ; 217(4): 739-744, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30103903

RESUMEN

BACKGROUND: Microvascular invasion (MVI) has recently been reported to be an independent prognostic factor in patients with hepatocellular carcinoma (HCC). This study compared the outcomes of adjuvant transarterial chemoembolization (A-TACE) after hepatic resection (HR) in patients with HCC involving MVI. METHODS: This prospective study involved 200 consecutive patients with MVI-HCC who underwent HR alone (n = 109) or HR with A-TACE (n = 91).The Kaplan-Meier method was used to compare disease-free survival (DFS) and overall survival (OS). RESULTS: The two groups showed similar DFS at 1, 2, and 3 years (P = 0.077). The A-TACE group showed significantly higher OS than the HR-only group (P = 0.030). Subgroup analysis showed that A-TACE was associated with significantly higher DFS and OS among patients with a tumor diameter >5 cm or with multinodular tumors. CONCLUSIONS: A-TACE may improve postoperative outcomes for MVI-HCC patients, especially those with tumor diameter >5 cm or multinodular tumors.


Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Quimioembolización Terapéutica/métodos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Vasculares/patología , Anciano , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/cirugía , Quimioterapia Adyuvante , Femenino , Humanos , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Invasividad Neoplásica/patología , Pronóstico , Estudios Prospectivos , Tasa de Supervivencia
17.
J Biomed Mater Res B Appl Biomater ; 100(6): 1654-61, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22707089

RESUMEN

Human vascular cells from saphenous veins have been used for cell seeding on the synthetic scaffolds for constructing tissue-engineered heart valve (TEHV). However, little is known about the seeding of human vascular cells on bovine pericardium, a potential natural scaffold for TEHV. This study was aimed to assess the basic in vitro and in vivo characteristics of the human vascular cells seeded on decellularized bovine pericardium. In vitro, bovine pericardium samples with cell seeding were inspected on day 7, 14, and 21 by histology, scanning electron microscopy, and immunohistochemistry. In vivo, experiments were performed in nude mice by bilateral dorsal incision for the implantation of decellularized bovine pericardium with and without cell seeding. Results demonstrated that a total of 8-10 × 10(6) cells were obtained within 4-5 wk by the primary co-culture, which were detected positive for von Willebrand factor, α-smooth muscle actin antibodies, and fibronectin, indicating the presence of endothelial cells, smooth muscle cells, and fibroblasts, respectively. In vitro, the seeded cells showed a steady increase of endothelial activity from day 1 to day 7 and remained stable until day 21. After 30 days of implantation in vivo, the cells on the decellularized bovine pericardium could differentiate directionally and show all the identities of human endothelial cells, smooth muscle cells, and fibroblasts. These results indicate that the human vascular cells from the saphenous vein are an optional cell source for seeding on decellularized bovine pericardium scaffold for constructing TEHV.


Asunto(s)
Bioprótesis , Células Endoteliales/citología , Células Endoteliales/metabolismo , Fibroblastos/citología , Prótesis Valvulares Cardíacas , Válvulas Cardíacas , Músculo Liso Vascular/citología , Miocitos del Músculo Liso/citología , Pericardio/química , Andamios del Tejido/química , Animales , Bovinos , Células Cultivadas , Técnicas de Cocultivo , Fibroblastos/metabolismo , Humanos , Masculino , Ratones , Ratones Desnudos , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Ingeniería de Tejidos/métodos
18.
Altern Lab Anim ; 38(3): 213-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20602537

RESUMEN

The accurate temperature control of a polymerase chain reaction (PCR) thermocycler was exploited in developing an in vitro model to study neutrophil activation during cardiopulmonary bypass. Neutrophils from 12 volunteers underwent temperature changes in a PCR thermocycler (37 degrees C for 30 minutes, 28 degrees C for 60 minutes, and then 37 degrees C for 90 minutes). Different co-incubates were applied to neutrophils, as follows: Group A: phosphate-buffered saline solution; Group B: platelet activating factor (PAF) ; Group C: platelet-depleted plasma; Group D: platelet-depleted plasma + PAF; and Group E: platelet-rich plasma. Membrane-bound elastase (MBE) activity was measured every 30 minutes throughout the experiment. MBE activity decreased significantly after hypothermia, compared with the baseline level (p < 0.001), and it resumed an increase after re-warming. Among all co-incubates, platelet-rich plasma was the most potent pro-inflammatory stimulus to neutrophils. A linear correlation was found between MBE and platelet count in platelet-rich plasma (p = 0.004). A novel in vitro model involving a PCR thermocycler has been proved to be reliable in the study of neutrophil activation during cardiopulmonary bypass. The model could possibly be used as an alternative to animals in the development of new drugs to combat neutrophil damage to tissues and organs during cardiopulmonary bypass in cardiac surgery.


Asunto(s)
Puente Cardiopulmonar , Activación Neutrófila/fisiología , Neutrófilos/inmunología , Reacción en Cadena de la Polimerasa/instrumentación , Plaquetas/inmunología , Calor , Humanos , Técnicas In Vitro , Elastasa de Leucocito/metabolismo , Reacción en Cadena de la Polimerasa/métodos
19.
J Biomed Mater Res B Appl Biomater ; 91(1): 354-61, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19507136

RESUMEN

Bovine pericardium has been extensively applied as the biomaterial for artificial heart valves and may potentially be used as a scaffold for tissue-engineered heart valves after decellularization. Although various methods of decellularization are currently available, it is unknown which method is the most ideal one for the decellularization for bovine pericardium. We compared three decellularization methods, namely, the detergent and enzyme extraction (DEE), the trypsin (TS), and the Triton X-100 and sodium-deoxycholate (TSD) method, to examine their efficacy on cell removal and their preservation of the mechanical function and the tissue matrix structure. Results indicated that decellularization was achieved by all the three methods as confirmed by hematoxylin-eosin staining, scanning electron microscopy, as well as quantitative DNA measurement. However, TS and TSD methods resulted in severe structural destruction of the bovine pericardium as shown by von Gieson staining and Gomori staining. Furthermore, both TS and TSD methods changed the mechanical property of the bovine pericardium, as evidenced by a lower elastic modulus, maximal-stress, maximal-disfiguration, maximal-load, and maximal-strain. In conclusion, the DEE method achieved both a complete decellularization and preservation of the mechanical function and tissue structure of the bovine pericardium. Thus, this method is superior to either the TS or the TSD method for preparing decellularized bovine pericardium scaffold for constructing tissue-engineered heart valves.


Asunto(s)
Detergentes/química , Prótesis Valvulares Cardíacas , Pericardio , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Bovinos , Ácido Desoxicólico/química , Implantación de Prótesis de Válvulas Cardíacas , Válvulas Cardíacas/citología , Ensayo de Materiales , Octoxinol/química , Pericardio/química , Pericardio/citología , Pericardio/metabolismo , Distribución Aleatoria , Tripsina/metabolismo
20.
Artif Organs ; 33(6): 448-55, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19473140

RESUMEN

Small-caliber decellularized xenografts with surface heparin coating are known to reduce in vivo thrombogenicity. This study was performed to examine whether heparin coating on the small-caliber decellularized xenografts would reduce macrophage infiltration and intimal hyperplasia. In a rabbit model of bilateral carotid implantation, each of the animals (n = 18) received a heparin-coated decellularized xenograft from a canine carotid artery on one side and a nonheparin-coated one on the other side. These experiments were terminated respectively at 1 week (n = 6), 3 weeks (n = 6), and 12 weeks (n = 6). Results showed that, compared with the nonheparin-coated grafts, the heparin-coated grafts had significantly less macrophage infiltration 1 week after implantation, identified by the mouse antirabbit macrophage antibody (RAM11)-positive cells on the vascular wall, covering all the proximal, middle, and distal parts of the grafts (P < 0.01). Moreover, the heparin-coated grafts also showed less deposition of proliferation cell nuclear antigen (PCNA)-positive cells on the vascular wall, indicating less cell proliferation, which was significant not only at 1 week (P < 0.01) but also at 12 weeks (P < 0.01). Intimal hyperplasia, measured by the intimal : media (I : M) ratio, was found similar in both groups at 1 and 3 weeks. However, the I : M ratio was significantly lower in the heparin-coated group than in the nonheparin-coated group at 12 weeks, especially in the proximal anastomosis area (0.76 +/- 0.12 vs. 0.345 +/- 0.06, P < 0.01). Heparin coating of small-caliber decellularized xenografts is associated with an early reduction of macrophage infiltration and intimal hyperplasia in a rabbit model of bilateral carotid artery implantation for 12 weeks. Thus, heparin coating appears to deliver not only the antithrombogeneity but also the antiproliferative property for small-caliber decellularized xenografts.


Asunto(s)
Heparina/farmacología , Macrófagos/efectos de los fármacos , Trasplante Heterólogo/métodos , Túnica Íntima/efectos de los fármacos , Túnica Íntima/patología , Animales , Implantación de Prótesis Vascular , Proliferación Celular/efectos de los fármacos , Femenino , Heparina/química , Hiperplasia , Macrófagos/citología , Masculino , Conejos
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