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1.
Pain Physician ; 27(5): E579-E587, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-39087967

RÉSUMÉ

BACKGROUND: Hip fracture surgeries in elderly patients often require spinal or general anesthesia, posing risks of severe hypotension and inadequate pain management. The optimal anesthesia type for minimizing these risks remains undetermined. Preliminary studies suggest that a combination of fascia iliaca block (FIB) and low-dose low-specific-gravity spinal anesthesia (LLSA) might offer a solution, but comprehensive evidence is lacking. OBJECTIVES: This study aimed to assess the efficacy of combining FIB with LLSA for reducing severe hypotension and enhancing analgesia during hip fracture surgery in elderly patients. STUDY DESIGN: A prospective, randomized controlled trial was conducted. SETTING: An operating theatre of a tertiary hospital. METHODS: The study comprised 68 patients. They were separated into 2 equal parallel groups 34 patients each: the FIB+LLSA group and the general anesthesia (GA) group. Patients aged 75-96 undergoing primary hip arthroplasty for hip fracture were randomized to receive either FIB+LLSA or GA. The primary outcome was the incidence of severe hypotension; secondary outcomes included postoperative pain, use of rescue analgesia, vasopressor dosage, and complications. RESULTS: We found a significantly lower incidence of severe hypotension in the FIB+LLSA group compared to the GA group (32.4% vs 67.6%). Additionally, postoperative pain scores were significantly lower, and the need for rescue analgesia was reduced in the FIB+LLSA group. Vasopressor use during surgery was also significantly lower in the FIB+LLSA group. The hospital stay was shorter in the FIB+LLSA group, with an average of 5.9 days compared to 6.7 days in the GA group. LIMITATIONS: The study's limitations include its single-center nature, which may limit the generalizability of the findings. Additionally, the inability to conduct a double-blind study could introduce biases, though measures were taken to minimize this. The sample size might not be sufficient to determine the broader implications of LLSA. CONCLUSIONS: Combining FIB with LLSA for elderly patients undergoing hip fracture surgery significantly reduces the incidence of severe intraoperative hypotension and postoperative pain. It also decreases the need for rescue analgesia and shortens hospital stays, suggesting that FIB+LLSA could be a beneficial regional anesthesia technique for elderly hip fracture surgery patients, aligning with enhanced recovery protocols.


Sujet(s)
Rachianesthésie , Fractures de la hanche , Hypotension artérielle , Bloc nerveux , Humains , Fractures de la hanche/chirurgie , Sujet âgé , Rachianesthésie/méthodes , Rachianesthésie/effets indésirables , Sujet âgé de 80 ans ou plus , Femelle , Mâle , Bloc nerveux/méthodes , Études prospectives , Douleur postopératoire/prévention et contrôle , Douleur postopératoire/traitement médicamenteux , Analgésie/méthodes , Fascia
2.
Front Neurol ; 15: 1365860, 2024.
Article de Anglais | MEDLINE | ID: mdl-38974682

RÉSUMÉ

Objectives: This study aimed to investigate the management of vascular risk factors, with a specific focus on understanding the various factors affecting risk factor control through an in-depth analysis of clinical data and a longitudinal follow-up of patients who have experienced ischemic strokes. Methods: A total of 1,572 participants were included in the analysis. We assessed thresholds for blood pressure (BP), low-density lipoprotein cholesterol (LDL-C), and glycated hemoglobin (HbA1c) levels to uncover the contextual conditions and factors affecting vascular risk factor control. Moreover, the study also scrutinized medication compliance at intervals of 3, 6, and 12 months post-onset. Logistic regression was used to adjust for confounding factors. Results: At 3, 6, and 12 months, BP,LDL, hemoglobin control targets were achieved in 50.7, 51.8, and 50.6%; 51.5, 59.4, and 50.6%; 48.1, 44.0, and 48.4%,respectively. Notably, age was associated with the achievement of BP control (odds ratio [OR], 0.96; 95% confidence intervals [CI], 0.94-0.98; p < 0.0001). Ethnic minorities (OR, 4.23; 95% CI, 1.19-15.09; p = 0.02) and individuals with coronary heart disease (OR, 0.5; 95% CI, 0.3-1.0; p = 0.05) experienced decreased BP control ratios. A previous history of stroke (OR, 1.7; 95% CI, 1.0-2.8; p = 0.03) and unrestricted alcohol consumption (OR, 3.3; 95% CI, 1.0-11.1; p = 0.05) was significantly associated with the achievement of lipid control. Furthermore, lifestyle modifications were significantly correlated with the achievement of BP control (OR, 0.19; 95% CI, 0.12-0.30; p < 0.01), blood glucose control (OR, 0.03; 95% CI, 0.01-0.08; p < 0.01), and blood lipid control (OR, 0.26; 95% CI, 0.16-0.42; p < 0.01). The absence of regular physical activity was associated with lower rates of glycemic (OR, 0.14; 95% CI, 0.06-0.36; p < 0.01) and lipid controls (OR, 0.55; 95% CI, 0.33-0.90; p = 0.01). Over time, overall medication compliance declined. Conclusion: Within the cohort of patients under medication, the compliance rate concerning vascular risk factors remains unsatisfactory. Attention should be paid to compliance with secondary prevention medications and enhance the control of vascular risk factors, as compliance emerges as the key to effective prevention.

3.
Bioresour Technol ; 407: 131142, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39043277

RÉSUMÉ

In this study, a sustainable and environmentally friendly method was developed for the enrichment and purification of phycocyanin from Spirulina platensis. This was achieved by utilizing a temperature-sensitive polymer, Pluronic F68, in an aqueous two-phase solvent system. The phase behavior of the temperature-sensitive polymer-based biphasic system was evaluated. The extraction conditions were optimized by both single-factor experiments and response surface methodology. Under the optimal conditions, the upper polymer-rich phase was recycled for sustainable phycocyanin extraction, resulting in a grade of 3.23 during the third extraction cycle. Pluronic F68 could be efficiently recovered and reused during the extraction process. The interaction mechanism between Pluronic F68 and phycocyanin was systematically studied using FT-IR and fluorescence analysis. This was further complemented by static and dynamic calculation of molecular motion through molecular docking and molecular dynamics simulation, indicating that hydrophobic segment of Pluronic F68 played a key role in the binding process with phycocyanin.


Sujet(s)
Technologie de la chimie verte , Phycocyanine , Poloxamère , Spirulina , Température , Phycocyanine/composition chimique , Phycocyanine/isolement et purification , Spirulina/composition chimique , Poloxamère/composition chimique , Technologie de la chimie verte/méthodes , Simulation de docking moléculaire , Spectroscopie infrarouge à transformée de Fourier , Eau/composition chimique , Polymères/composition chimique , Simulation de dynamique moléculaire
4.
Anal Bioanal Chem ; 415(29-30): 7235-7246, 2023 Dec.
Article de Anglais | MEDLINE | ID: mdl-37957327

RÉSUMÉ

Adulteration of meat and meat products causes a concerning threat for consumers. It is necessary to develop novel robust and sensitive methods which can authenticate the origin of meat species to compensate for the drawbacks of existing methods. In the present study, the sarcoplasmic proteins of six meat species, namely, pork, beef, mutton, chicken, duck and turkey, were analyzed by one-dimensional gel electrophoresis. It was found that enolase could be used as a potential biomarker protein to distinguish between livestock and poultry meats. The glycosylation sites and glycans of enolase were analyzed by UPLC-QTOF-MS and a total of 41 glycopeptides were identified, indicating that the enolase N-glycopeptide profiles of different meats were species-specific. The identification models of livestock meat, poultry and mixed animal were established based on the glycopeptide contents, and the explanation degree of the three models was higher than 90%. The model prediction performance and feasibility results showed that the average prediction accuracy of the three models was 75.43%, with the animal-derived meat identification model showing superiority in identifying more closely related species. The obtained results indicated that the developed strategy was promising for application in animal-derived meat species monitoring and the quality supervision of animal-derived food.


Sujet(s)
Glycopeptides , Viande rouge , Bovins , Animaux , Viande/analyse , Volaille , Viande rouge/analyse , Poulets , Enolase
5.
Anal Sci ; 39(7): 1129-1142, 2023 Jul.
Article de Anglais | MEDLINE | ID: mdl-37000321

RÉSUMÉ

In the present work, a potential solid-phase extraction (SPE) material based on graphene anchored with platinum nanoparticles (Pt-Graphene) was prepared and characterized by scanning electron micrographs and transmission electron micrograph. The carbamates residues in fish were enriched by SPE filled with Pt-Graphene and detected by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The proposed extraction protocol exhibited satisfactory recoveries (76.5-115.6%), low limit of quantitation values in µg kg-1 level, and good precision for the studied ten carbamates. These results demonstrated the feasibility of the proposed protocol. The developed Pt-Graphene nanoparticles showed excellent performance for extracting analytes at trace levels, indicating that it could be used as a potential SPE sorbent in food residue analysis.


Sujet(s)
Graphite , Nanoparticules métalliques , Pesticides , Animaux , Chromatographie en phase liquide/méthodes , Graphite/composition chimique , Chromatographie en phase liquide à haute performance/méthodes , Spectrométrie de masse en tandem/méthodes , Nanoparticules métalliques/analyse , Platine , Pesticides/analyse , Extraction en phase solide/méthodes , Carbamates/analyse , Carbamates/composition chimique
6.
Mar Drugs ; 21(1)2023 Jan 05.
Article de Anglais | MEDLINE | ID: mdl-36662216

RÉSUMÉ

Alzheimer's disease (AD), a neurodegenerative disease, is one of the most intractable illnesses which affects the elderly. Clinically manifested as various impairments in memory, language, cognition, visuospatial skills, executive function, etc., the symptoms gradually aggravated over time. The drugs currently used clinically can slow down the deterioration of AD and relieve symptoms but cannot completely cure them. The drugs are mainly acetylcholinesterase inhibitors (AChEI) and non-competitive N-methyl-D-aspartate receptor (NDMAR) antagonists. The pathogenesis of AD is inconclusive, but it is often associated with the expression of beta-amyloid. Abnormal deposition of amyloid and hyperphosphorylation of tau protein in the brain have been key targets for past, current, and future drug development for the disease. At present, researchers are paying more and more attention to excavate natural compounds which can be effective against Alzheimer's disease and other neurodegenerative pathologies. Marine natural products have been demonstrated to be the most prospective candidates of these compounds, and some have presented significant neuroprotection functions. Consequently, we intend to describe the potential effect of bioactive compounds derived from marine organisms, including polysaccharides, carotenoids, polyphenols, sterols and alkaloids as drug candidates, to further discover novel and efficacious drug compounds which are effective against AD.


Sujet(s)
Maladie d'Alzheimer , Produits biologiques , Maladies neurodégénératives , Humains , Sujet âgé , Maladie d'Alzheimer/traitement médicamenteux , Produits biologiques/pharmacologie , Produits biologiques/usage thérapeutique , Acetylcholinesterase/métabolisme , Peptides bêta-amyloïdes/métabolisme
7.
Mar Drugs ; 20(4)2022 Apr 07.
Article de Anglais | MEDLINE | ID: mdl-35447930

RÉSUMÉ

A method for batch preparation of fucoxanthin from brown algae was established, which possessed the advantages of high yield and high purity. The ultrasonic-assisted extraction method was used to obtain a crude extract from Sargassum fusiforme as the separation sample. Then the crude extract was separated by elution-extrusion countercurrent chromatography. The optimum preparation conditions of fucoxanthin were determined as follows: n-hexane-ethanol-water (20:9:11, v:v:v) as a two-phase solvent system, the mobile phase flow rate was 5 mL min-1, the revolution speed was 800 r min-1, the loading capacity was 60 mg 10 mL-1 and the temperature was 25 °C. By this method, 12.8 mg fucoxanthin with a purity of 94.72% was obtained from the crude extract of Sargassum fusiforme. In addition, when the loading capacity was 50 mg 10 mL-1, the purity of fucoxanthin reached 96.01%. Two types of by-products, chlorophyll and pheophytin, could also be obtained during the process of separation. This optimal method was further applied to separate fucoxanthin from Laminaria japonica and Undaria pinnatifida, and 6.0 mg and 9.7 mg fucoxanthin with a purity of 96.24% and 92.62% were acquired, respectively. Therefore, it was demonstrated that the preparation method of fucoxanthin established in this study had an applicability to brown algae, which improved the utilization value of raw materials.


Sujet(s)
Phaeophyceae , Sargassum , Chromatographie en phase liquide à haute performance , Mélanges complexes , Distribution à contre-courant/méthodes , Phaeophyceae/composition chimique , Sargassum/composition chimique , Xanthophylles/composition chimique
8.
Foods ; 12(1)2022 Dec 22.
Article de Anglais | MEDLINE | ID: mdl-36613268

RÉSUMÉ

This study was aimed to investigate the structural and immunological properties of parvalbumin from mandarin fish during the Maillard reaction. The microwave-assisted the Maillard reaction was optimized by orthogonal designed experiments. The results showed that the type of sugar and heating time had a significant effect on the Maillard reaction (p < 0.05). The SDS-PAGE analysis displayed that the molecular weight of parvalbumin in mandarin fish changed after being glycated with the Maillard reaction. The glycated parvalbumin was analyzed by Nano-LC-MS/MS and eleven glycation sites as well as five glycation groups were identified. By using the indirect competitive ELISA method, it was found that microwave heating gave a higher desensitization ability of mandarin fish parvalbumin than induction cooker did. In vitro gastric digestion experiments showed that microwave-heated parvalbumin was proved to be digested more easily than that cooked by induction cookers. The microwave-assisted Maillard reaction modified the structure of parvalbumin and reduced the immunoreactivity of parvalbumin of mandarin fish.

9.
Ultrason Sonochem ; 77: 105671, 2021 Sep.
Article de Anglais | MEDLINE | ID: mdl-34304119

RÉSUMÉ

The development of green and sustainable extraction technologies for various naturally active biomaterials is gaining increasing attention due to their environmentally friendly advantages. In this work, the ultrasonic-assisted extraction of fucoxanthin from edible brown algae Sargassum fusiforme using different green solvents was presented. Ethyl lactate, limonene, soybean oil, and sunflower oil were used in place of traditional organic solvents. Ethyl lactate showed similar performance to organic solvents, whereas limonene and vegetable oil exhibited higher selectivity for fucoxanthin. Moreover, the effects of various extraction factors, including liquid/solid ratio, extraction time, extraction temperature, as well as amplitude were studied. The optimal conditions were optimized as follows: liquid/solid ratio, 40 mL/g; extraction time, 27 min; extraction temperature, 75 ℃; amplitude, 53%; and solvent, ethyl lactate. Optimal model of second-order kinetic parameters (rate constant, equilibrium concentration, and initial extraction rate) was successfully developed for describing the dynamic ultrasonic extraction process under different operating conditions.


Sujet(s)
Modèles chimiques , Sargassum/composition chimique , Solvants/composition chimique , Ondes ultrasonores , Xanthophylles/isolement et purification , Technologie de la chimie verte , Cinétique
10.
Appl Microbiol Biotechnol ; 104(12): 5283-5292, 2020 Jun.
Article de Anglais | MEDLINE | ID: mdl-32307571

RÉSUMÉ

Salmonella is a serious foodborne pathogen responsible for more than 90 million cases of gastroenteritis worldwide annually. Due to the gradual increase in antibiotic-resistant Salmonella strains, the identification of natural antibacterial substances is urgently needed. Herein, we purified natural L-phenyl lactic acid (L-PLA) from Lactobacillus plantarum ZJ316 and revealed its antimicrobial mode against Salmonella enterica subsp. enterica ATCC 14028. L-PLA (98.14% pure) was obtained using the macroporous resin XAD-16, solid-phase extraction (SPE), reverse-phase high-performance liquid chromatography (RP-HPLC), and chiral chromatography. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results showed that the cell morphology was severely compromised. Transmembrane electrical potential (ΔΨ), transmembrane pH gradient (ΔpH), intracellular ATP level, extracellular electrical conductivity (EC), and genomic DNA analyses were employed to evaluate the antibacterial mode of action of L-PLA. The proton motive force (PMF) and ATP of Salmonella cells rapidly dissipated, and the EC markedly increased. The gel retardation assay demonstrated that L-PLA could bind to genomic DNA and intercalate into the nucleic acids. The anti-Salmonella mode of action of L-PLA was attributed to the destruction of the cell membrane and genomic DNA binding. This research suggests that L-PLA has potential applications as an antimicrobial agent in food, medicine, and other fields. KEY POINTS: • Natural L-PLA was purified from L. plantarum ZJ316 with a purity of 98.14%. • L-PLA effectively inhibited Salmonella strains by antibacterial activities and MICs. • Membrane destruction and binding with DNA are the anti-Salmonella modes of L-PLA.


Sujet(s)
Antibactériens/pharmacologie , Lactates/pharmacologie , Lactobacillus plantarum/composition chimique , Salmonella/effets des médicaments et des substances chimiques , Membrane cellulaire/effets des médicaments et des substances chimiques , ADN bactérien/métabolisme , Génome bactérien , Lactates/isolement et purification , Lactobacillus plantarum/génétique , Potentiels de membrane/effets des médicaments et des substances chimiques , Tests de sensibilité microbienne , Salmonella/classification
11.
Mar Drugs ; 17(12)2019 Dec 09.
Article de Anglais | MEDLINE | ID: mdl-31818004

RÉSUMÉ

Sargassum horneri, a sargassaceae brown alga, is one of the main species in the subtidal seaweeds flora extensively distributed in the Yellow and East China Sea. It has been proven that the phytosterols are an important class of bioactive substances in S. horneri. In this work, a counter-current chromatography approach is proposed for preparative separation of phytol and two analogue sterols from a crude extract of S. horneri. A two-phase solvent system composed of n-hexane-acetonitrile-methanol (5:5:6, v/v) was selected and optimized. The effects of rotary speed and flow rate on the retention of the stationary phase were carefully studied. Under the optimum conditions, phytol and two analogue sterols, fucosterol and saringosterol, were baseline separated, producing 19.8 mg phytol, 23.7 mg fucosterol, and 3.1 mg saringosterol from 300 mg of crude S. horneri extract in one-step separation. The purities of three target compounds were all above 85%. The structures of phytol and two sterols were identified by nuclear magnetic resonance spectroscopy.


Sujet(s)
Distribution à contre-courant/méthodes , Phytostérols/isolement et purification , Sargassum/composition chimique , Spectroscopie par résonance magnétique , Phytol/composition chimique , Phytol/isolement et purification , Phytostérols/composition chimique , Solvants/composition chimique , Stigmastérol/analogues et dérivés , Stigmastérol/composition chimique , Stigmastérol/isolement et purification
12.
Proc Natl Acad Sci U S A ; 116(20): 9753-9758, 2019 05 14.
Article de Anglais | MEDLINE | ID: mdl-31036647

RÉSUMÉ

Particulate organic carbon (POC) produced in the surface ocean sinks through the water column and is respired at depth, acting as a primary vector sequestering carbon in the abyssal ocean. Atmospheric carbon dioxide levels are sensitive to the length (depth) scale over which respiration converts POC back to inorganic carbon, because shallower waters exchange with the atmosphere more rapidly than deeper ones. However, estimates of this carbon regeneration length scale and its spatiotemporal variability are limited, hindering the ability to characterize its sensitivity to environmental conditions. Here, we present a zonal section of POC fluxes at high vertical and spatial resolution from the GEOTRACES GP16 transect in the eastern tropical South Pacific, based on normalization to the radiogenic thorium isotope 230Th. We find shallower carbon regeneration length scales than previous estimates for the oligotrophic South Pacific gyre, indicating less efficient carbon transfer to the deep ocean. Carbon regeneration is strongly inhibited within suboxic waters near the Peru coast. Canonical Martin curve power laws inadequately capture POC flux profiles at suboxic stations. We instead fit these profiles using an exponential function with flux preserved at depth, finding shallow regeneration but high POC sequestration below 1,000 m. Both regeneration length scales and POC flux at depth closely track the depths at which oxygen concentrations approach zero. Our findings imply that climate warming will result in reduced ocean carbon storage due to expanding oligotrophic gyres, but opposing effects on ocean carbon storage from expanding suboxic waters will require modeling and future work to disentangle.

13.
J Geophys Res Oceans ; 124(12): 9338-9363, 2019 Dec.
Article de Anglais | MEDLINE | ID: mdl-32064221

RÉSUMÉ

Since the 1980-1990s, international research efforts have augmented our knowledge of the physical and chemical properties of the Arctic Ocean water masses, and recent studies have documented changes. Understanding the processes responsible for these changes is necessary to be able to forecast the local and global consequences of these property evolutions on climate. The present work investigates the distributions of geochemical tracers of particle fluxes and circulation in the Amerasian Basin and their temporal evolution over the last three decades (from stations visited between 1983 and 2015). Profiles of 230-thorium (230Th) and 231-protactinium (231Pa) concentrations and neodymium isotopes (expressed as εNd) measured in the Amerasian Basin prior to 2000 are compared to a new, post-2000s data set. The comparison shows a large scale decrease in dissolved 230Th and 231Pa concentrations, suggesting intensification of scavenging by particle flux, especially in coastal areas. Higher productivity and sediment resuspension from the shelves appear responsible for the concentration decrease along the margins. In the basin interior, increased lateral exchanges with the boundary circulation also contribute to the decrease in concentration. This study illustrates how dissolved 230Th and 231Pa, with εNd support, can provide unique insights not only into changes in particle flux but also into the evolution of ocean circulation and mixing.

14.
Mar Drugs ; 16(2)2018 Feb 24.
Article de Anglais | MEDLINE | ID: mdl-29495262

RÉSUMÉ

The contamination of foods and animal feeds with trichothecene mycotoxins is a growing concern for human and animal health. As such, large quantities of pure trichothecene mycotoxins are necessary for food safety monitoring and toxicological research. A new and effective method for the purification of trichothecene mycotoxins from a marine fungus, Fusarium sp. LS68, is described herein. Preparative high-speed countercurrent chromatography (HSCCC) was utilized for the scalable isolation and purification of four trichothecene mycotoxins for the first time in stepwise elution mode, with a biphasic solvent system composed of hexanes-EtOAc-CH3OH-H2O (6:4:5:5, v/v/v/v) and (8.5:1.5:5:5,v/v/v/v). This preparative HSCCC separation was performed on 200 mg of crude sample to yield four trichothecene mycotoxins, roridin E (1), roridin E acetate (2), verrucarin L acetate (3), and verrucarin J (4) in a single run, with each of >98% purity. These compounds were identified by MS, ¹H NMR, 13C NMR, and polarimetry. The results demonstrate an efficient HSCCC method for the separation of trichothecene mycotoxins, which can be utilized to produce pure commercial and research standards.


Sujet(s)
Organismes aquatiques/composition chimique , Fusarium/composition chimique , Mycotoxines/composition chimique , Mycotoxines/isolement et purification , Trichothécènes/composition chimique , Trichothécènes/isolement et purification , Chromatographie en phase liquide à haute performance/méthodes , Distribution à contre-courant/méthodes , Analyse des risques et maitrise des points critiques/méthodes , Spectroscopie par résonance magnétique/méthodes , Solvants/composition chimique
15.
Mar Drugs ; 15(11)2017 Nov 10.
Article de Anglais | MEDLINE | ID: mdl-29125580

RÉSUMÉ

Nowadays, various drugs on the market are becoming more and more resistant to numerous diseases, thus declining their efficacy for treatment purposes in human beings. Antibiotic resistance is one among the top listed threat around the world which eventually urged the discovery of new potent drugs followed by an increase in the number of deaths caused by cancer due to chemotherapy resistance as well. Accordingly, marine cyanobacteria, being the oldest prokaryotic microorganisms belonging to a monophyletic group, have proven themselves as being able to generate pharmaceutically important natural products. They have long been known to produce distinct and structurally complex secondary metabolites including peptides, polyketides, alkaloids, lipids, and terpenes with potent biological properties and applications. As such, this review will focus on recently published novel compounds isolated from marine cyanobacteria along with their potential bioactivities such as antibacterial, antifungal, anticancer, anti-tuberculosis, immunosuppressive and anti-inflammatory capacities. Moreover, various structural classes, as well as their technological uses will also be discussed.


Sujet(s)
Produits biologiques/composition chimique , Produits biologiques/métabolisme , Cyanobactéries/métabolisme , Antibactériens/composition chimique , Antibactériens/métabolisme , Antibactériens/pharmacologie , Antinéoplasiques/composition chimique , Antinéoplasiques/métabolisme , Antinéoplasiques/pharmacologie , Produits biologiques/pharmacologie , Cyanobactéries/composition chimique , Structure moléculaire
16.
PLoS One ; 12(8): e0181904, 2017.
Article de Anglais | MEDLINE | ID: mdl-28837583

RÉSUMÉ

Natural killer (NK) cells are a highly heterogeneous population of innate lymphocytes that constitute our first line of defense against several types of tumors and microbial infections. Understanding the heterogeneity of these lymphocytes requires the ability to integrate their underlying phenotype with dynamic functional behaviors. We have developed and validated a single-cell methodology that integrates cellular phenotyping and dynamic cytokine secretion based on nanowell arrays and bead-based molecular biosensors. We demonstrate the robust passivation of the polydimethylsiloxane (PDMS)-based nanowells arrays with polyethylene glycol (PEG) and validated our assay by comparison to enzyme-linked immunospot (ELISPOT) assays. We used numerical simulations to optimize the molecular density of antibodies on the surface of the beads as a function of the capture efficiency of cytokines within an open-well system. Analysis of hundreds of individual human peripheral blood NK cells profiled ex vivo revealed that CD56dimCD16+ NK cells are immediate secretors of interferon gamma (IFN-γ) upon activation by phorbol 12-myristate 13-acetate (PMA) and ionomycin (< 3 h), and that there was no evidence of cooperation between NK cells leading to either synergistic activation or faster IFN-γ secretion. Furthermore, we observed that both the amount and rate of IFN-γ secretion from individual NK cells were donor-dependent. Collectively, these results establish our methodology as an investigational tool for combining phenotyping and real-time protein secretion of individual cells in a high-throughput manner.


Sujet(s)
Cytokines/métabolisme , Immunophénotypage , Cellules tueuses naturelles/immunologie , Antigènes CD56/immunologie , Polydiméthylsiloxanes , Test ELISA , Protéines liées au GPI/immunologie , Humains , Cellules tueuses naturelles/effets des médicaments et des substances chimiques , Récepteurs du fragment Fc des IgG/immunologie , Analyse sur cellule unique , 12-Myristate-13-acétate de phorbol/pharmacologie
17.
J Sep Sci ; 40(11): 2326-2334, 2017 Jun.
Article de Anglais | MEDLINE | ID: mdl-28371341

RÉSUMÉ

The unicellular alga Chlorella vulgaris is a well-known health food. It has been proven that the minor phytosterols, ergosterol and its analogue, are an important class of bioactive substances in C. vulgaris. In this work, a recycling counter-current chromatographic approach was proposed for preparative separation of two analogue sterols from crude extract of C. vulgaris. The separation unit was set up with a type-J instrument coupled with a column switching valve. A two-phase solvent system composed of n-hexane/dichloromethane/acetonitrile (10:3:7, v/v/v) was selected and optimized. After five cycles of separation, two analogue sterols were baseline separated, producing 11.7 mg 26-nor-25-isopropyl-5,7,22-trien-3ß-ol and 20.3 mg ergosterol from 300 mg of C. vulgaris extract. Their purities were both above 95%. The structures of two sterols were identified by using NMR spectroscopy.


Sujet(s)
Chlorella vulgaris/composition chimique , Distribution à contre-courant , Phytostérols/isolement et purification , Solvants
18.
Neuroscience ; 343: 165-173, 2017 02 20.
Article de Anglais | MEDLINE | ID: mdl-27932309

RÉSUMÉ

Exercise is increasingly being used as a treatment for alcohol use disorders (AUD), but the interactive effects of alcohol and exercise on the brain remain largely unexplored. Alcohol damages the brain, in part by altering glial functioning. In contrast, exercise promotes glial health and plasticity. In the present study, we investigated whether binge alcohol would attenuate the effects of subsequent exercise on glia. We focused on the medial prefrontal cortex (mPFC), an alcohol-vulnerable region that also undergoes neuroplastic changes in response to exercise. Adult female Long-Evans rats were gavaged with ethanol (25% w/v) every 8h for 4days. Control animals received an isocaloric, non-alcohol diet. After 7days of abstinence, rats remained sedentary or exercised for 4weeks. Immunofluorescence was then used to label microglia, astrocytes, and neurons in serial tissue sections through the mPFC. Confocal microscope images were processed using FARSIGHT, a computational image analysis toolkit capable of automated analysis of cell number and morphology. We found that exercise increased the number of microglia in the mPFC in control animals. Binged animals that exercised, however, had significantly fewer microglia. Furthermore, computational arbor analytics revealed that the binged animals (regardless of exercise) had microglia with thicker, shorter arbors and significantly less branching, suggestive of partial activation. We found no changes in the number or morphology of mPFC astrocytes. We conclude that binge alcohol exerts a prolonged effect on morphology of mPFC microglia and limits the capacity of exercise to increase their numbers.


Sujet(s)
Hyperalcoolisation rapide/physiopathologie , Microglie/physiologie , Activité motrice/physiologie , Plasticité neuronale/physiologie , Cortex préfrontal/physiopathologie , Animaux , Astrocytes/effets des médicaments et des substances chimiques , Astrocytes/anatomopathologie , Astrocytes/physiologie , Laboratoire automatique , Hyperalcoolisation rapide/anatomopathologie , Hyperalcoolisation rapide/thérapie , Numération cellulaire , Dépresseurs du système nerveux central/toxicité , Modèles animaux de maladie humaine , Éthanol/toxicité , Traitement par les exercices physiques , Femelle , Technique d'immunofluorescence , Traitement d'image par ordinateur , Microglie/effets des médicaments et des substances chimiques , Microglie/anatomopathologie , Microscopie confocale , Plasticité neuronale/effets des médicaments et des substances chimiques , Neurones/effets des médicaments et des substances chimiques , Neurones/anatomopathologie , Neurones/physiologie , Cortex préfrontal/effets des médicaments et des substances chimiques , Cortex préfrontal/anatomopathologie , Répartition aléatoire , Rat Long-Evans , Mode de vie sédentaire
19.
Science ; 354(6310): 296, 2016 10 21.
Article de Anglais | MEDLINE | ID: mdl-27846529

RÉSUMÉ

Winograd and Coplen question the thorium-230 distribution model proposed to explain the age bias observed with increasing depth during Termination II. We have evaluated both criticisms and find that all samples display virtually identical fabrics, argue that the modern setting is not analogous to the conditions during Termination II, and reiterate the robustness of our age models. Our conclusions remain unchanged.


Sujet(s)
Climat , Thorium , Modèles théoriques
20.
Science ; 351(6269): 165-8, 2016 Jan 08.
Article de Anglais | MEDLINE | ID: mdl-26744404

RÉSUMÉ

The driving force behind Quaternary glacial-interglacial cycles and much associated climate change is widely considered to be orbital forcing. However, previous versions of the iconic Devils Hole (Nevada) subaqueous calcite record exhibit shifts to interglacial values ~10,000 years before orbitally forced ice age terminations, and interglacial durations ~10,000 years longer than other estimates. Our measurements from Devils Hole 2 replicate virtually all aspects of the past 204,000 years of earlier records, except for the timing during terminations, and they lower the age of the record near Termination II by ~8000 years, removing both ~10,000-year anomalies. The shift to interglacial values now broadly coincides with the rise in boreal summer insolation, the marine termination, and the rise in atmospheric CO2, which is consistent with mechanisms ultimately tied to orbital forcing.

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