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1.
Phys Chem Chem Phys ; 22(6): 3734-3743, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32010904

RESUMO

The chaperonin system GroEL-GroES is present in all kingdoms of life and rescues proteins from improper folding and aggregation upon internal and external stress conditions, including high temperatures and pressures. Here, we set out to explore the thermo- and piezostability of GroEL, GroES and the GroEL-GroES complex in the presence of cosolvents, nucleotides and salts employing quantitative FTIR spectroscopy and small-angle X-ray scattering. Owing to its high biological relevance and lack of data, our focus was especially on the effect of pressure on the chaperonin system. The experimental results reveal that the GroEL-GroES complex is remarkably temperature stable with an unfolding temperature beyond 70 °C, which can still be slightly increased by compatible cosolutes like TMAO. Conversely, the pressure stability of GroEL and hence the GroEL-GroES complex is rather limited and much less than that of monomeric proteins. Whereas GroES is pressure stable up to ∼5 kbar, GroEl and the GroEl-GroES complex undergo minor structural changes already beyond 1 kbar, which can be attributed to a dissociation-induced conformational drift. Quite unexpectedly, no significant unfolding of GroEL is observed even up to 10 kbar, however, i.e., the subunits themselves are very pressure stable. As for the physiological relevance, the structural integrity of the chaperonin system is retained in a relatively narrow pressure range, from about 1 to 1000 bar, which is just the pressure range encountered by life on Earth.


Assuntos
Chaperonina 10/química , Chaperonina 60/química , Meio Ambiente , Pressão , Estabilidade Proteica , Temperatura Ambiente
2.
Waste Manag ; 102: 686-697, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31790927

RESUMO

Mechanical biological treatment (MBT) can greatly reduce the amount of municipal solid waste (MSW) and has become a hot topic in environmental geotechnical engineering. To study the effects of factors such as the pressure, dry density, compression time under pressure, strain, and hydraulic gradient, permeability tests with saturated MBT waste were conducted by using a compression and permeability combined apparatus in an environmental geotechnical laboratory. The results showed that Darcy's law was applicable to the saturated MBT waste. The permeability coefficient was found to be inversely related to the pressure, dry density, compression time under pressure and strain. The logarithmic permeability coefficient and the variables (e.g., pressure) could largely be fitted to a linear function. Additionally, a prediction model for the permeability coefficient was established, and the permeability coefficient at different depths of MBT landfills was predicted. The results were then compared to previous studies on MSW and MBT waste to investigate the permeability mechanism.


Assuntos
Eliminação de Resíduos , China , Pressão , Resíduos Sólidos , Instalações de Eliminação de Resíduos
3.
Urology ; 135: 154-158, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31585200

RESUMO

OBJECTIVE: To identify patient and component specific factors that predispose patients to device-related complications when undergoing pressure-regulating balloon (PRB) exchange in men with an artificial urinary sphincter (AUS). METHOD: From 2009 to 2018, 55 patients underwent AUS revision with placement of a higher pressure 71-80 cm H2O PRB to treat recurrent stress incontinence. Patient demographics, perioperative data, and postoperative outcomes were examined and multivariable logistic regression analyses performed to identify predictors of erosion and mechanical failure. RESULT: After a median follow-up of 26.4 months (range: 6-103.7 months), 21 of 55 (38.1%) patients developed a device-related complication that required operative repair or removal of the AUS. Four (7.3%) patients developed erosion after the PRB pressure increase and 5 patients showed evidence of impending erosion on follow-up and underwent successful revision surgery. Twelve patients developed mechanical failure (cuff leak, n = 7; pump malfunction, n =4; unidentified fluid loss, n = 1). Multivariable logistic regression analysis found that increasing body mass index was a predictor of mechanical failure. Hypertension and lower body mass index were found to increase the risk of cuff erosion whereas radiotherapy was not. CONCLUSION: In the carefully selected patient, PRB exchange can be performed to treat recurrent incontinence in patients with an AUS, including those treated with pelvic radiotherapy. Our data suggest that this technique is susceptible to a high rate of revision surgery. As such, when revising a functional AUS system, meticulous preoperative screening, comprehensive informed consent, and follow-up protocols are essential in minimizing adverse events.


Assuntos
Falha de Prótese , Reoperação/instrumentação , Incontinência Urinária por Estresse/cirurgia , Esfíncter Urinário Artificial/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Pressão , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
4.
Anaesthesia ; 75(2): 179-186, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31631314

RESUMO

The aim of this study was to evaluate the effectiveness of cricoid and paralaryngeal force for oesophageal entrance occlusion during induction of anaesthesia. Seventy-four patients were included in this randomised, crossover study. The relative position of the glottis and outer anteroposterior diameter of the upper oesophageal entrance were assessed at baseline, after the application of 30 N cricoid and paralaryngeal force, and after induction of anaesthesia. The occlusion rate of the oesophageal entrance with cricoid and paralaryngeal force was assessed during direct laryngoscopy. The relative position of the upper oesophageal entrance to the glottis changed in 45 out of 74 patients after induction of anaesthesia and during direct laryngoscopy compared with the awake state. The application of cricoid and paralaryngeal force decreased the mean (SD) diameter of the upper oesophageal entrance to a similar degree in awake (8.5 (2.1) mm to 6.4 (1.7) mm and 6.5 (1.6) mm, respectively; p < 0.001) and anaesthetised (8.7 (2.2) mm to 6.5 (1.7) mm and (6.7 (1.9) mm, respectively; p < 0.001) states. During direct laryngoscopy, the occlusion rate of the oesophageal entrance was greater with cricoid compared with paralaryngeal force (46/74 vs. 26/74, respectively; p = 0.002). The relative position of the upper oesophageal entrance to the glottis may change after induction of anaesthesia and during direct laryngoscopy. Cricoid and paralaryngeal force both decrease the diameter of the upper oesophageal entrance in awake and anaesthetised states. Occlusion of the oesophageal entrance is achieved more frequently with cricoid force compared with paralaryngeal force during direct laryngoscopy.


Assuntos
Anestesia/métodos , Cartilagem Cricoide/anatomia & histologia , Esôfago/anatomia & histologia , Laringoscopia/métodos , Laringe/anatomia & histologia , Ultrassonografia/métodos , Estudos Cross-Over , Feminino , Humanos , Intubação Intratraqueal/métodos , Masculino , Pessoa de Meia-Idade , Pressão
5.
J Forensic Sci ; 65(1): 274-275, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31469426

RESUMO

A 29-year-old man died at the scene of an altercation from a stab wound to the left side of the neck. At autopsy, careful in situ examination of the common carotid artery did not reveal any evidence of hemorrhage or apparent vascular injury. However, applying pressure to the chest wall and underlying thoracic viscera (lungs and heart) resulted in filling of the collapsed vessel with blood causing hemorrhage from a small incision on the medial aspect of the common carotid artery. Release of pressure and drying of the dissection field enabled the artery to be opened and the small defect to be identified. This technique may be used to temporarily restore blood to a vessel to help identify a small bleeding point that may otherwise be difficult to detect.


Assuntos
Lesões das Artérias Carótidas/patologia , Hemorragia/patologia , Pressão , Tórax , Ferimentos Perfurantes/patologia , Adulto , Autopsia/métodos , Artéria Carótida Primitiva/patologia , Exsanguinação/etiologia , Humanos , Masculino
6.
World Neurosurg ; 133: e84-e88, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31470152

RESUMO

BACKGROUND: Spinopelvic sagittal parameters have a significant influence on adjacent segment degeneration (ASD) after fusion surgery. The association between ASD and sagittal balance is not well understood. The purpose of this study was to investigate the biomechanical influence of various sacral slope (SS) degrees on adjacent segments after transforaminal lumbar interbody fusion (TLIF) at the L4-L5 level. METHODS: We conducted a finite element model of the L1-S1 based on computed tomography scan images. The L1-S1 model with L4-L5 TLIF was modified with various SS degrees (33°, 38°, 43°, and 48°) to investigate the biomechanical influence of SS on adjacent segments. The range of motion (ROM) and intradiscal pressure (IDP) of the adjacent segments (L3-L4 and L5-S1) were compared among models using various SS angles. RESULTS: When the SS angle increased, the ROM and IDP in L5-S1 decreased gradually after TLIF at the L4-L5 level in all motion patterns. Nevertheless, the ROM and IDP in L3-L4 were not significantly different among various SS angles. CONCLUSIONS: Decreased SS after lumbar fusion surgery may pose a higher risk of ASD. Therefore, restoring appropriate SS should be considered during decision-making prior to fusion surgery to reduce the risk of degenerative changes.


Assuntos
Vértebras Lombares/cirurgia , Sacro/diagnóstico por imagem , Fusão Vertebral/métodos , Antropometria , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Disco Intervertebral/fisiopatologia , Vértebras Lombares/diagnóstico por imagem , Pressão , Amplitude de Movimento Articular , Sacro/patologia , Tomografia Computadorizada por Raios X
7.
Biophys Chem ; 257: 106280, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31877450

RESUMO

High pressure acts as a mild and non-destructive activation mode for chemical reactions. However, in the context of organo-/biocatalysis, high pressure activation, has not been investigated systematically, although there are significant benefits such as rate acceleration, increased selectivity and the possibility of suppressing side product formation. The influence of hydrostatic pressure in solution on the catalytic performance of enzymes and small molecule organocatalysts such as amino acids, peptides, amines, cinchona alkaloids and thioureas is evaluated in this review, taking reactivity and selectivity as a probe to identify pressure effects on biomolecules.


Assuntos
Aminoácidos/química , Alcaloides de Cinchona/química , Peptídeos/química , Pressão , Catálise , Reação de Cicloadição , Enzimas/química , Enzimas/metabolismo , Soluções/química , Tioureia/análogos & derivados
8.
Biophys Chem ; 257: 106258, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31881504

RESUMO

Recent methodological progress in quantum-chemical calculations using the "embedded cluster reference interaction site model" (EC-RISM) integral equation theory is reviewed in the context of applying it as a solvation model for calculating pressure-dependent thermodynamic and spectroscopic properties of molecules immersed in water. The methodology is based on self-consistent calculations of electronic and solvation structure around dissolved molecules where pressure enters the equations via an appropriately chosen solvent response function and the pure solvent density. Besides specification of a dispersion-repulsion force field for solute-solvent interactions, the EC-RISM approach derives the electrostatic interaction contributions directly from the wave function. We further develop and apply the method to a variety of benchmark cases for which computational or experimental reference data are either available in the literature or are generated specifically for this purpose in this work. Starting with an enhancement to predict hydration free energies at non-ambient pressures, which is the basis for pressure-dependent molecular population estimation, we demonstrate the performance on the calculation of the autoionization constant of water. Spectroscopic problems are addressed by studying the biologically relevant small osmolyte TMAO (trimethylamine N-oxide). Pressure-dependent NMR shifts are predicted and compared to experiments taking into account proper computational referencing methods that extend earlier work. The experimentally observed IR blue-shifts of certain vibrational bands of TMAO as well as of the cyanide anion are reproduced by novel methodology that allows for weighing equilibrium and non-equilibrium solvent relaxation effects. Taken together, the model systems investigated allow for an assessment of the reliability of the EC-RISM approach for studying pressure-dependent biophysical processes.


Assuntos
Modelos Químicos , Espectroscopia de Ressonância Magnética , Metilaminas/síntese química , Metilaminas/química , Simulação de Dinâmica Molecular , Pressão , Teoria Quântica
9.
Phys Chem Chem Phys ; 22(2): 838-853, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31840715

RESUMO

The five fundamental units of the genetic code: uracil (U), thymine (T), cytosine (C), adenine (A) and guanine (G) are known for extremely low vapor pressure and low thermal stability at elevated temperatures. Therefore, application of conventional techniques for the determination of sublimation enthalpies and vapor pressures fails to provide accurate results. Recently, a Fast Scanning Calorimetry method (FSC) for vapor pressure determination was developed for investigation of extremely low volatile, as well as for thermally unstable molecular and ionic molecules. This success has encouraged application of the FSC method for determination of vapor pressures and sublimation enthalpies of the five nucleobases, where available literature data are in disarray. The thermodynamic data of the nucleobases available in the literature were collected, evaluated, and combined with our experimental results to reconcile available experimental data. The set of evaluated thermochemical data on the five nucleobases was recommended as the benchmark properties for these thermally labile compounds.


Assuntos
Adenina/química , Calorimetria , Citosina/química , Guanina/química , Termodinâmica , Timina/química , Uracila/química , Pressão , Volatilização
10.
Food Chem ; 305: 125475, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518841

RESUMO

Pea protein-stabilized nanoemulsions were prepared to encapsulate vitamin D with the aim to develop novel non-dairy functional foods for vitamin D fortifications. Homogenization conditions of 20 kpsi and two homogenization cycles were identified as optimal conditions for producing stable nanoemulsions. The nanoemulsions exhibited controllable sizes (170-350 nm), good stability with zeta-potential of -25 mV, and high vitamin encapsulation efficiency (94-96%). Cellular uptake efficiency of small sized nanoemulsions (233 nm) was ~2.5 times higher than large sized nanoemulsions (350 nm). Interestingly, protein-based nanoemulsions exhibited significantly higher cellular uptake than emulsions prepared using a combination of protein and lecithin. The vitamin D transport efficiency across Caco-2 cells for small sized nanoemulsions (233 nm) was ~5.3 times greater than free vitamin D suspension. This research demonstrated that pea protein can be used as an effective emulsifier for preparing food nanoemulsions, which may enhance vitamin D bioavailability and improve vitamin deficiency status in aged population.


Assuntos
Emulsões/química , Nanoestruturas/química , Proteínas de Ervilha/química , Vitamina D/química , Células CACO-2 , Sobrevivência Celular , Emulsificantes/química , Humanos , Lecitinas/química , Nanoestruturas/toxicidade , Tamanho da Partícula , Pressão , Estabilidade Proteica , Vitamina D/metabolismo
11.
Food Chem ; 303: 125386, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473454

RESUMO

The present work investigated the influences of ultrahigh pressure (UHP), ultrasound (US) and their combination (UHP-US) as pretreatments on properties of vacuum-freeze dried strawberry slices. During vacuum-freeze drying, drying duration and total energy consumption of UHP sample, US sample and UHP-US sample was decreased. After the UHP or US pretreatments, a* value (redness), antioxidative substances (total anthocyanin content, total flavonoid content, total phenolic content, diphenyl picrylhydrazyl (DPPH), hydroxyl (-OH) radical-scavenging assay), hardness and cross-section areas of matrix in the dried slices were significantly (P < 0.05) increased. Transverse relaxation times and peak area corresponding to free water in the pretreated samples were obviously decreased, indicating lower mobility in the pretreated samples. As compared with UHP or US individually, UHP in combination with US increased those parameters more pronouncedly. Therefore, UHP and US are promising techniques for the vacuum-freeze drying processing of strawberry products.


Assuntos
Dessecação , Conservação de Alimentos/métodos , Fragaria/química , Frutas/química , Pressão , Ondas Ultrassônicas , Antocianinas/análise , Antioxidantes/análise , Antioxidantes/química , Cor , Flavonoides/análise , Liofilização , Frutas/efeitos da radiação , Fenóis/análise , Vácuo
12.
Comput Methods Biomech Biomed Engin ; 23(1): 33-42, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31805773

RESUMO

This study numerically investigated the hemodynamics of a patient-specific coronary artery fistula (CAF) before and after the fistula closure. The results indicated that the dilated fistula result in inadequate perfusion to other healthy aortas. Disturbed blood flow, aberrant WSSs, local negative pressure gradients and sharp pressure changes are shown in both untreated and occluded fistula. Furthermore, extreme high WSS appeared at the fistula bending after the terminal closure. It was concluded that the fistula closure may effectively improve the phenomenon of stealing blood but worsen the unfavorable hemodyanmics predisposing the thrombosis formation due to its geometrical torturosity.


Assuntos
Vasos Coronários/fisiopatologia , Fístula/fisiopatologia , Hidrodinâmica , Adulto , Doença da Artéria Coronariana/fisiopatologia , Diástole/fisiologia , Hemorreologia , Humanos , Imagem Tridimensional , Masculino , Modelos Cardiovasculares , Pressão , Estresse Mecânico , Sístole/fisiologia
13.
Food Chem ; 308: 125555, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655483

RESUMO

Saccharomyces cerevisiae flor yeast is used for the first time in sparkling wine-making. Twenty-six oenological variables and fifty-three volatile metabolites are quantified in the middle (P = 3 bar) and at the end (P = 6 bar) of the second fermentation, carried out in open and closed bottles. A heat-map of volatiles and the fingerprints obtained for ten chemical families and ten odorant series visualize the changes for each condition. Terpenes, fatty acids and volatile phenols increased their contents by pressure effect at the end of the study by 25.0, 7.8 and 2.2%, respectively. The remaining families decrease between 17.4% and 30.1% for furanic compounds and esters in the same stage. A Principal Component Analysis established that nine volatiles are mainly affected by pressure and five by fermentation stage. The use of ethanol-tolerant flor yeasts constitutes an innovative procedure for the enhancement of the sparkling wines diversification.


Assuntos
Dióxido de Carbono/química , Fermentação , Saccharomyces cerevisiae/metabolismo , Vinho/análise , Dióxido de Carbono/análise , Ésteres/análise , Odorantes/análise , Pressão
14.
Food Chem ; 307: 125526, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648172

RESUMO

Effective management of mycotoxins rely on stringent regulation and routine surveillance of food/feed commodities via efficient analysis, hence the continuous need for improved methods. The present study developed, optimized and validated a modified pressurized hot water extraction (PHWE) method for the simultaneous extraction of multi-mycotoxins from maize and subsequent quantification on LC-MS/MS. The PHWE system was modified using ethanol (EtOH) as a cosolvent, while a numerical modelling approach, the central composite design (CCD), was adopted for the optimization of the extraction conditions. Using the optimized method, it was possible to effectively extract and quantify 15 different mycotoxins from maize in a single step with satisfactory linearities (0.986-0.999), recoveries (14-124%) and other associated method validation parameters. Further efficacious application of the method to real samples re-affirmed the prospects of PHWE as a suitable, cost-effective and greener alternative to traditional methods of mycotoxin extraction.


Assuntos
Micotoxinas/análise , Água/química , Zea mays/metabolismo , Cromatografia Líquida de Alta Pressão , Temperatura Alta , Limite de Detecção , Micotoxinas/isolamento & purificação , Pressão , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
15.
Food Chem ; 306: 125615, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31622833

RESUMO

Phycocyanin (PC), a plant-based protein with interesting biological activity, is rarely directly applied in the food industry because it has structural and functional limitations. This study combined ultra-high-pressure (UHP) treatment with glycation to improve PC functionality and explored resulting structural changes using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, scanning electron microscopy, Fourier-transform infrared spectroscopy, circular dichroism, and UV-visible spectroscopy. The UHP treatment obviously improved the speed and degree of glycation and the composite-modified PC (CM-PC) showed high solubility and good emulsifying and foaming performance. Scanning electron microscopy images showed the CM-PC surface was loose and fluffy. Gel electrophoresis, Fourier-transform infrared spectroscopy, and circular dichroism results demonstrated that the content of α-helix decreased from 78.1% in PC to 26.6% in CM-PC, and hydroxyl groups were introduced. UV-visible spectroscopy showed that the mechanism of composite modification involved stretching of the PC and promotion of binding with sugars.


Assuntos
Ficocianina/química , Spirulina/química , Dicroísmo Circular , Eletroforese em Gel de Poliacrilamida , Emulsões/metabolismo , Glicosilação , Pressão , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Food Chem ; 306: 125602, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31629969

RESUMO

Effects of high-pressure treatments (HPT, 100-300 MPa, 9 min, 25 °C) on the in vitro digestibility of gel-type meat products were studied using a simulated digestion-model. In vitro digestibilities of the cooked rabbit meat batters throughout the simulated oral-, gastric-, and intestinal-phases were determined. Peptides in the intestinal digesta were identified via Mass Spectrometer. Results revealed that in vitro digestibilities of HPT-samples were higher than the control (1.98%, 6.13% and 61.31% for oral-, gastric- and intestinal-phase respectively) throughout the digestion (P < 0.05). Alterations of the peptide profiles were induced by HPT, showing HPT-specific patterns of mutual peptides in the digestive products. Coupled with the identifications of salt-soluble proteins from raw batters, it was confirmed that myofibrillar proteins account for the major contribution to the HPT-induced changes. The results indicated that HPT can potentially be an effective technology to improve the digestibility of meat products.


Assuntos
Produtos da Carne/análise , Peptídeos/química , Animais , Culinária , Pressão , Proteólise , Coelhos
17.
Arch Oral Biol ; 109: 104570, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31568992

RESUMO

OBJECTIVE: The aim of this study is to investigate the effects of 17ß-Estradiol (E2) at different concentrations combined with cyclical compressive stress on the proliferation and differentiation of mandibular condylar chondrocytes (MCCs). DESIGN: MCCs, isolated from female Sprague-Dawley rats, were exposed to E2 at different concentration, cyclical compressive stress or the combination, effects of which on MCCs proliferation and differentiation were detected. RESULTS: E2 at physiological concentration (10-9 mol/L) has lower proliferative effects on MCCs, compared with non-physiological concentration (10-12 mol/L or 10-6 mol/L). For MCCs differentiation, effects of E2 at different concentration are totally opposite: E2 at 10-9 mol/L promotes MCCs differentiation, but at 10-12 mol/L or 10-6 mol/L, it inhibits MCCs differentiation. When combined with E2 at 10-9 mol/L, cyclical compressive stress shows synergistic effect on proliferation and differentiation. However, when combined with E2 at 10-12 mol/L or 10-6 mol/L cyclical compressive stress reverses the inhibition in MCCs differentiation provoked by E2 at 10-12 mol/L or 10-6 mol/L. CONCLUSION: Effects of E2 combined with cyclical compressive stress on MCCs proliferation and differentiation are different, which suggests that orthodontist should take fully consideration of the levels of E2 and adopt comprehensive strategies, so as to achieve better orthodontic effect.


Assuntos
Condrócitos/citologia , Estradiol/farmacologia , Côndilo Mandibular/citologia , Pressão , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Feminino , Ratos , Ratos Sprague-Dawley
18.
Zool Res ; 41(1): 3-19, 2020 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-31840949

RESUMO

Hypobaric hypoxia (HH) exposure can cause serious brain injury as well as life-threatening cerebral edema in severe cases. Previous studies on the mechanisms of HH-induced brain injury have been conducted primarily using non-primate animal models that are genetically distant to humans, thus hindering the development of disease treatment. Here, we report that cynomolgus monkeys ( Macaca fascicularis) exposed to acute HH developed human-like HH syndrome involving severe brain injury and abnormal behavior. Transcriptome profiling of white blood cells and brain tissue from monkeys exposed to increasing altitude revealed the central role of the HIF-1 and other novel signaling pathways, such as the vitamin D receptor (VDR) signaling pathway, in co-regulating HH-induced inflammation processes. We also observed profound transcriptomic alterations in brains after exposure to acute HH, including the activation of angiogenesis and impairment of aerobic respiration and protein folding processes, which likely underlie the pathological effects of HH-induced brain injury. Administration of progesterone (PROG) and steroid neuroprotectant 5α-androst-3ß,5,6ß-triol (TRIOL) significantly attenuated brain injuries and rescued the transcriptomic changes induced by acute HH. Functional investigation of the affected genes suggested that these two neuroprotectants protect the brain by targeting different pathways, with PROG enhancing erythropoiesis and TRIOL suppressing glutamate-induced excitotoxicity. Thus, this study advances our understanding of the pathology induced by acute HH and provides potential compounds for the development of neuroprotectant drugs for therapeutic treatment.


Assuntos
Androstanóis/farmacologia , Hipóxia/veterinária , Macaca fascicularis , Doenças dos Macacos/prevenção & controle , Progesterona/farmacologia , Transcriptoma , Androstanóis/administração & dosagem , Animais , Encefalopatias/prevenção & controle , Encefalopatias/veterinária , Cálcio/metabolismo , Regulação da Expressão Gênica , Hipóxia/patologia , Leucócitos/metabolismo , Masculino , Fármacos Neuroprotetores/farmacologia , Pressão , Progesterona/administração & dosagem
19.
J Surg Res ; 245: 249-256, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31421370

RESUMO

BACKGROUND: Technical improvement of gastrojejunostomy is critical in bariatric and metabolic surgery. In this study, a novel magnetic compression approach for gastrojejunostomy was evaluated. MATERIALS AND METHODS: Both cylindrical and rectangular magnets were used in rabbits, and the magnets were named according to their location. All the magnets were perorally introduced into the stomach. The position of the jejunal magnet was controlled by a connecting line. When the jejunal magnet spontaneously entered the jejunum, the gastric magnet was introduced into the stomach. An extracorporeal magnet was used to guide these two magnets together, and the magnet pair was left to create a side-to-side anastomosis. The state of the animals and extrusion time of the magnets were observed. The anastomoses were evaluated by burst pressure and histology. RESULTS: Gastrojejunostomy was successfully established in all animals. Cylindrical and rectangular magnets spontaneously entered the jejunum through the pylorus within 2.4 ± 0.5 and 6.0 ± 0.8 d, respectively (P < 0.01). The cylindrical and rectangular magnet pairs fell off within 15.3 ± 0.8 and 11.9 ± 1.1 d, respectively (P < 0.01). The burst pressures were statistically similar between the two types of magnets (P > 0.05). Histological examination showed sealed anastomoses with mild inflammation of the mucosa and fibrosis within the submucosa. CONCLUSIONS: The feasibility and efficacy of establishing gastrojejunostomy by guidewire introduction of magnets, which were guided together with an extracorporeal magnet, were confirmed in rabbits. In humans, with the clinical use of this procedure, surgery would be greatly simplified.


Assuntos
Derivação Gástrica/instrumentação , Gastrostomia/instrumentação , Jejunostomia/instrumentação , Imãs , Animais , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Derivação Gástrica/efeitos adversos , Derivação Gástrica/métodos , Gastrostomia/efeitos adversos , Gastrostomia/métodos , Jejunostomia/efeitos adversos , Jejunostomia/métodos , Masculino , Modelos Animais , Pressão , Coelhos
20.
Talanta ; 207: 120310, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594599

RESUMO

Recently, superficially porous particles (SPPs) have been intensively studied and employed for highly efficient and fast separations. In this paper, the SiO2@SiO2 SPPs were synthesized by an improved polymerization-induced colloid aggregation (PICA) method using urea-formaldehyde polymer as the template. The agglomeration of silica core during modification with ureidopropyltrimethoxysilane (UPS) can not only be avoided by reflux in neutral ethanol solution, but also the secondary nucleation of the colloidal silica sol can be inhibited via optimizing the reaction conditions including pH, temperature, colloidal silica sol concentration and the reaction time. The shell thickness and pore size of SPPs can be controlled successfully by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The SPP-C18 columns packed using octadecyltrichlorosilane (ODS) modified SPPs with different pore sizes were employed to separate small solutes and proteins. The baseline separations of 6 kinds of alkyl benzenes and 5 kinds of aromatic alcohol homologues were achieved within 4 min by the SPP-C18 column with 8 nm pore size. Compared with the commercial BEH-C18 column, more than 50,000/m of the plate number of propylbenzene was obtained, and the former provided higher column efficiency to separate small solutes than the latter. Meanwhile, 6 kinds of proteins were also separated completely within 2 min using the SPP-C18 column with 40 nm pore size. In addition, the SPP-C18 capillary column was applied to separate and identify the BSA/HeLa/mouse liver digests with capillary LC-MSMS, respectively. The results indicate that more proteins and peptides can be identified using SPP-C18 capillary column compared with commercial silica-C18 capillary column. The result demonstrates that the prepared SPP-C18 column provides higher column efficiency and the SPPs synthesized with the improved PICA method shows a great potential application for the fast separation of small solutes and proteins.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Microesferas , Polimerização , Proteínas/isolamento & purificação , Dióxido de Silício/química , Animais , Coloides , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Porosidade , Pressão , Temperatura Ambiente , Fatores de Tempo
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