Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.236
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
Int J Biol Macromol ; 141: 460-475, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31473318

RESUMO

Based on the concept of endophytic fungus, if endophytic fungus can produce the same or similar product as the host plant, which will get rid of the restrictions of farmland, seasonal and pest, the active product could be sustainably obtained. In this study, an endophytic fungus polysaccharide FP showing the similar structure with the host Dendrobium officinale polysaccharide (DOP) was sustainably and cost-effectively obtained under preferred reaction conditions with different C/N ratio. The FP with high yield up to 2.77 ±â€¯0.51 g/L showed same monosaccharide composition with DOP as well as some host-plant-associated polysaccharides in published literatures. The main chain of FP was composed by →3,6)-ß-L-Man-(1→, α-D-Glc-(1→, →4)-α-D-Glc-(1→, →3,6)-ß-D-Gal-(1→, and →6)-ß-D-Gal-(1→, while the side chain was α-D-Glc-(1→. Meanwhile, FP was confirmed as a safe polysaccharide with good antioxidant, antiglycation and immunomodulatory activities. Furthermore, TLR2 and TLR4 were confirmed as the membrane receptors of FP on RAW264.7 cells.

2.
J Orthop Surg Res ; 14(1): 286, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31488167

RESUMO

BACKGROUND: Osteomyelitis is a challenge for orthopedic surgeons due to its protracted treatment process. Microwaves (MWs) can increase blood perfusion due to their thermal effect. Furthermore, MWs demonstrated significant bactericidal effects in vitro. In the present study, we assumed that the application of a 2450-MHz-frequency MW together with systemic antibiotic treatment would provide synergy for the treatment of acute osteomyelitis. METHODS: The medullary cavity of the right tibia was inoculated with 107 CFU of methicillin-sensitive Staphylococcus aureus (MSSA-ATCC 29213) in 40 rats, and the rats were randomly divided into four groups according to treatment: group I, saline (control); group II, saline + MW therapy; group III, systemic cefuroxime; and group IV, systemic cefuroxime + MW therapy. MWs were applied for 20 min per day to the infected limbs, and all rats were sacrificed on the 7th day. The severity of tibial osteomyelitis was assessed by quantitative culture analysis. RESULTS: Bacterial counts in groups III and IV were significantly reduced compared with those in the control (p = 0.001 and < 0.001, respectively). Furthermore, significant differences were detected between groups III and IV (p = 0.033). However, the difference between groups I and II was nonsignificant (p = 0.287). CONCLUSION: Our experimental model suggests that MW therapy provides a significant synergy for systemic antibiotic treatment. However, further clinical trials are required to safely use this treatment modality in patients.

3.
Life Sci ; : 116863, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31513817

RESUMO

AIMS: To determine whether dimethyl fumarate (DMF) can protect against lipopolysaccharide (LPS) -induced myocardial injury. MAIN METHODS: H9c2 cells pretreated with or without DMF were stimulated with LPS. Cell viability and apoptosis were evaluated. Nrf2 and HO-1 expression were detected using Western blotting. Mitochondrial morphology, mitochondrial and superoxide production were observed using confocal microscope. Mitochondrial respiration function was measured using Seahorse bioanalyzer. KEY FINDINGS: (1) The cell viability decreased, LDH release and apoptosis increased in LPS- challenged H9c2 cells. DMF pretreatment brought a higher cell viability, and a lower LDH leakage and apoptosis than those of LPS group (P < 0.01). (2) DMF pretreatment resulted in an increased Nrf2 and HO-1 expression, and enhanced nuclear Nrf2 level in LPS-challenged cells (P < 0.01). (3) Nrf2-siRNA could inhibit DMF-induced enhancement of HO-1 expression and cell viability, and partly abolish DMF-induced reduction of LDH leakage and apoptosis. (4) ERK1/2 inhibitor PD98059 could not only prevent the DMF-induced enhancement of nuclear Nrf2 and HO-1, but also inhibit DMF-induced increase in cell viability. (5) Compared with LPS-challenged cells, DMF pretreatment caused a lower production of mitochondrial superoxide and a higher mitochondrial membrane potential, which could be abolished by Nrf2-siRNA. (6) DMF could attenuate LPS-induced mitochondrial fragmentation and improved mitochondrial respiration function by enhancement of the oxygen consumption rate of basal respiration and ATP production in LPS-challenged cells (P < 0.01). SIGNIFICANCE: DMF protects cardiomyocytes against LPS-induced damage. ERK1/2-dependent activation of Nrf2/HO-1 pathway is responsible for DMF-induced cardioprotection via reduction of oxidative stress, improvement of mitochondrial morphology and energy metabolism.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31515769

RESUMO

Rapid economic and population growth exacerbates water resource shortages and various associative ecological factors. Additionally, climate change makes it difficult to predict potential eco-environmental risks. The Government of China enacted a large-scale forestation campaign in the northwest to cope with the region's increasingly severe eco-environmental problems. This study applied GIS software to analyze areas where water resource changes have occurred and the reasons behind water shortages. Notwithstanding fluctuations, there was a general increase in water resource trends between 1980 and 2015. On a regional scale, we observed an increasing trend for provinces with large water resources, including Xinjiang, Qinghai, and Xizang, which accounted for 84.58% of the total increases observed between 1980 and 2015. The water resource trend for the region as a whole increased exponentially with increasing rainfall and decreasing evapotranspiration. Furthermore, water consumed by artificial forests in Northwest China reached 14 billion cubic meters, which is equivalent to 5.22% of its total annual water resources. In contrast, this study determined that under natural vegetation conservation practices, water consumed would have decreased to 10.13 billion cubic meters in 2015. Accordingly, this study concluded that the Government of China should change its policy from planting more trees to protecting natural vegetation.

6.
Biotechnol Bioeng ; 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31502661

RESUMO

Considerable attention has been given to the development of robust fermentation processes, but microbial contamination and phage infection remain deadly threats that need to be addressed. In this study, a robust Escherichia coli BL21(DE3) strain was successfully constructed by simultaneously introducing a nitrogen and phosphorus (N&P) system in combination with a CRISPR/Cas9 system. The N&P metabolic pathways were able to express formamidase and phosphite dehydrogenase in the host cell, thus enabled cell growth in auxotrophic MOPS medium with formamide and phosphite as nitrogen and phosphorus sources, respectively. N&P metabolic pathways also allowed efficient expression of heterologous proteins, such as GFP and chitinase, while contaminating bacteria or yeast species could hardly survive in this medium. The host strain was further engineered by exploiting the CRISPR/Cas9 system to enhance the resistance against phage attack. The resultant strain was able to grow in the presence of T7 phage at a concentration of up to 2×107 PFU/ml and produce GFP with a yield of up to 30 µg/(109 CFU), exhibiting significant advantages over conventional engineered E. coli. This newly engineered, robust E. coli BL21(DE3) strain therefore shows great potential for future applications in industrial fermentation. This article is protected by copyright. All rights reserved.

8.
ACS Appl Mater Interfaces ; 11(34): 31484-31489, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31365224

RESUMO

The use of phototaxis to move droplets in liquids offers the opportunity to emulate natural processes such as the controlled transport of materials in fluidic environments and to undertake chemistry at specific locations. We have developed a photoactive organic droplet, whose movement in aqueous solution is driven by a photoinitiator, as a result of a light-induced reaction within the droplet generating a Marangoni flow. The photoinitiator not only drives the droplet motion but can also be used to initiate polymerization following transfer of the droplet to a specific location and its merging with a monomer-containing droplet. The same light is used to control the transport of the droplet and the polymerization. The efficacy of this droplet transport and reactor system has been demonstrated by the site-specific underwater polymerization of N-isopropylacrylamide to repair a leaking vessel and the adhesion of two materials together.

9.
Gene ; 715: 144027, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31374327

RESUMO

OBJECTIVES: To explore the clinical and molecular characteristics of a Chinese Zhuang minority patient with leukocyte adhesion deficiency type-1 (LAD-1) and glucose-6-phosphate dehydrogenase deficiency (G6PDD). METHODS: Routine clinical and physical examinations were performed, and patient data was collected and analyzed. Protein expression levels of Itgb2 and glucose-6-phosphate dehydrogenase (G6pd) proteins were assessed by flow cytometry and the glucose-6-phosphate (G6P) substrate method, respectively. Whole exome sequencing was performed to investigate genetic variations of the patient and his parents. RESULTS: The patient had fester disease and delayed separation of the umbilical cord at birth. Staphylococcus was detected in the fluid secretion of the auditory meatus of the patient. He exhibited a recurrent cheek scab, swollen hand, and swollen gum. Hematological examination indicated dramatic elevation of leukocytes including lymphocytes, monocytes, neutrophils and eosinophils. A novel homozygous mutation was detected in the ITGB2 gene of the patient, which was determined to be a two nucleotide deletion at the site of c.1537-1538 (c.1537-1538delGT), causing a frameshift of 24 amino acids from p.513 and inducing a stop codon (p.V513Lfs*24). A base substitution mutation was identified at c.1466 (c.1466G>T) of G6PD on chromosome X of the patient, which resulted in an amino acid change from arginine to leucine at p.489 (p.R489L). The patient also showed deficient lymphocyte expression of CD18 (2.99%) and significant downregulation of the G6pd protein. CONCLUSIONS: The patient was diagnosed with G6PDD and moderate LAD-1. The combination of LAD-1 and G6PDD in this case may have been due to the high incidence of genetic disease in this minority ethnic population. Analyzing existing LAD-1 and G6PDD cases from different populations can facilitate disease diagnosis and treatment. Particularly, reporting pathogenic mutations of LAD-1 and G6PDD will be crucial for genetic testing and prenatal diagnosis in an effort to decrease the incidence of these diseases.


Assuntos
Antígenos CD18/genética , Deficiência de Glucosefosfato Desidrogenase/genética , Homozigoto , Síndrome da Aderência Leucocítica Deficitária/genética , Mutação de Sentido Incorreto , Substituição de Aminoácidos , Grupo com Ancestrais do Continente Asiático , Antígenos CD18/metabolismo , Deficiência de Glucosefosfato Desidrogenase/patologia , Humanos , Lactente , Síndrome da Aderência Leucocítica Deficitária/metabolismo , Síndrome da Aderência Leucocítica Deficitária/patologia , Leucócitos/metabolismo , Leucócitos/patologia , Masculino
10.
ACS Appl Mater Interfaces ; 11(35): 32366-32372, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31397991

RESUMO

Glycopolymers have emerged as powerful and versatile glycan analogues for the investigation of cellular signal transduction. In this study, a layer of the glycopolymer-brush (GlyB) interface was functionalized on the surface of gold substrates. In order to enhance the capability and accessibility of this transducer interface, a combined protocol of copper(0)-mediated living radical polymerization (Cu(0)-LRP) with subsequent "CuAAC" click reaction was utilized to synthesize a set of novel glycopolymer precursors with a tunable scaffold structure and pyranose ligands. The resulting glycopolymer exhibited a fine-tuned molecular weight with a minor dispersity of 1.27. Through surface plasmon resonance (SPR) analysis, various GlyB interfaces exhibiting different saccharide moieties (glucose, mannose, and galactose) were examined to study their adhesion or antiadhesion potential toward three types of proteins, concanavalin A, bovine serum albumin, and peanut agglutinin (PNA). The strong affinity between poly(galactose) and PNA was further employed to construct a proof-of-concept aggregation-mediated sensing system. This minimal naked-eye sensor that consisted of only two substances, namely, gold nanoparticles and glycopolymers, was characterized and tested for its potential in protein quantification.

11.
J Pharm Biomed Anal ; 176: 112818, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31446297

RESUMO

An unpredictable ghost peak was intermittently observed during the impurity separation of cefaclor and formulation by high performance liquid chromatography (HPLC) with a content from below the reported threshold to approximately 0.3% in different laboratories. Through a series of investigations, the ghost peak was identified as an unusual on-column degradant of cefaclor formed under elevated column temperature but was not an actual sample impurity. The chemical structure of the degradant was determined by spectroscopic methods, including high resolution mass spectrometry (HRMS) and 1H-NMR. Consequently, the unknown peak was identified as a C-4 oxidative decarboxylation analog of cefaclor. The formation mechanism of the analog is proposed, and it is suggested that elevated column temperature during HPLC analysis has a profound effect on the degradation. Dissolved oxygen in the mobile phase may promote the formation of the ghost peak. The degradation can be suppressed by using a column temperature below 30 °C. Moreover, several other prevention measures are suggested based upon the results of the investigation.

12.
Shanghai Kou Qiang Yi Xue ; 28(2): 201-203, 2019.
Artigo em Chinês | MEDLINE | ID: mdl-31384910

RESUMO

PURPOSE: To explore a safe, effective and functional surgical treatment for children of Pierre Robin sequence (PRS) with cleft palate. METHODS: Twelve children of PRS with cleft palate underwent mandibular distraction osteogenesis before cleft palate surgery in order to correct severe hypoxia. A modified palatoplasty was then performed, the palatal flaps on both sides were not elevated in the anterior portions to prevent soft palate backward moving, and the levator veli palatini was repositioned simultaneously. RESULTS: All children achieved velopharyngeal closure without dyspnea after follow-up of 10-12 months. CONCLUSIONS: Measures should be taken to avoid backward movement of the soft palate, which may result in dyspnea of children with PRS in palatoplasty.

13.
Org Lett ; 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31414818

RESUMO

An efficient iodide-catalyzed/hydrogen peroxide mediated sulfenylation and selenylation of unprotected uracil and its derivatives with simple thiols and diselenides was established. This coupling tolerates a broad variety of functional groups to provide diverse 5-sulfur/selenium-substituted uracil derivatives in good to excellent yields (up to 93%).

16.
17.
J Exp Clin Cancer Res ; 38(1): 367, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31431194

RESUMO

In the publication of this article [1], there is an error in Fig. 5C (panel 4, group of InmiR-26a + silinc01296 in SW620). The revised Fig. 5 which includes 5C has now been included in this correction.

18.
Artigo em Inglês | MEDLINE | ID: mdl-31446069

RESUMO

The body weight-selected lines of chickens are a model for understanding factors that predispose an individual to anorexia or obesity. The high body weight-selected (HWS) individuals are compulsive eaters that become obese whereas the low body weight-selected (LWS) are relatively lean and hypophagic. The objective of this study was to measure gene expression of various preadipocyte, proliferation, metabolic, and apoptotic markers in the stromal-vascular fraction and adipocytes from LWS and HWS adipose tissue. Although preadipocyte and proliferation markers were more highly expressed in the stromal-vascular fraction of LWS than HWS chicks, greater expression of granzyme-A and the presence of more annexin V-positive cells suggests that apoptosis may limit the adipogenic potential of adipocyte precursor cells and represent a novel mechanism that regulates the expansion of adipose tissue. Results provide insights on cellular mechanisms associated with adipose tissue development in the lean and obese state.

19.
Int Immunopharmacol ; 75: 105782, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31376623

RESUMO

Sepsis-induced myocardial dysfunction (SIMD) is a manifestation of severe sepsis and is the main cause of increased mortality in sepsis patients. Naringin (Nar) has been reported to possess various biological activities and pharmacological properties. Therefore, the present study was undertaken to evaluate whether Nar can protect rats from the effects of LPS-induced SIMD. SD Rats were pre-treated with Nar (50 and 100 mg/kg) for 7 days before administration of a single dose of LPS (10 mg/kg, i.p.) on the seventh day. We found that Nar treatment markedly improved the global strain and strain rate of longitudinal, circumference, and radial direction (GLS/GLSr, GCS/GCSr, GRS/GRSr) compared to the LPS group. The layer-specific strain decreased gradually from the endocardial layer to epicardial layer, and the most serious damage occurred in the endocardial layer. Moreover, Nar significantly decreased the levels of pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) and myocardial enzymes (CK, LDH, and AST) induced by LPS and attenuated the inflammation response. Finally, Nar also inhibited NF-κB nuclear translocation and the activity of iNOS in H9c2 cardiomyocytes by activating PI3K/AKT signaling pathway. These results suggest that naringin may possess novel therapeutic potential for protection against LPS-induced myocardial dysfunction.

20.
Brain Behav ; : e01369, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31397082

RESUMO

OBJECTIVES: Interleukin-33, a newly identified member of interleukin-1 family, had been confirmed to play a crucial role in regulating inflammatory responses in various disease. However, the exact role of interleukin-33 in the disease process of acute ischemic stroke still remains unclear. This study aims to demonstrate the relationship between interleukin-33 levels and long-term functional outcome as well as ischemic stroke recurrence. METHODS: Three hundred and four first-ever acute ischemic stroke patients were recruited and basic information and history of all subjects taken within 72 hr on admission. The functional outcome was estimated by Barthel index. The multivariate logistic regression was used to analyze the prognosis, while the Cox proportional hazard model was applied to assess the recurrence risk. RESULTS: Out of 304 subjects, 259 patients successfully completed scheduled two-year follow-up. We found that higher interleukin-33 levels correlated positively with better prognosis as compared with those with lower interleukin-33 levels who presented with poorer outcome (62.45 ± 20.50 ng/ml vs. 51.58 ± 19.16 ng/ml, p < .001). After adjustment of all confounders, interleukin-33 was associated with the one-year prognosis with an adjusted odds ratio of 0.956 (95% confidence interval, 0.937-0.976, p < .001). Furthermore, interleukin-33 levels were also closely related to recurrent ischemic stroke with an adjusted hazard ratio of 0.979 (95% confidence interval, 0.961-0.997, p = .025). CONCLUSIONS: IL-33 can be used to predict the long-term outcomes and ischemic stroke recurrence in first-ever acute ischemic stroke patients.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA