Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 448
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-34639411

RESUMO

Acetaminophen is the most common over-the-counter pain and fever medication used by pregnant women. While European studies suggest acetaminophen exposure in pregnancy could affect childhood asthma development, findings are less consistent in other populations. We evaluated whether maternal prenatal acetaminophen use is associated with childhood asthmatic symptoms (asthma diagnosis, wheeze, dry cough) in a Los Angeles cohort of 1201 singleton births. We estimated risk ratio (RR) and 95% confidence interval (CI) for childhood asthmatic outcomes according to prenatal acetaminophen exposure. Effect modification by maternal race/ethnicity and psychosocial stress during pregnancy was evaluated. The risks for asthma diagnosis (RR = 1.39, 95% CI 0.96, 2.00), wheezing (RR = 1.25, 95% CI 1.01, 1.54) and dry cough (RR =1.35, 95% CI 1.06, 1.73) were higher in children born to mothers who ever used acetaminophen during pregnancy compared with non-users. Black/African American and Asian/Pacific Islander children showed a greater than two-fold risk for asthma diagnosis and wheezing associated with the exposure. High maternal psychosocial stress also modified the exposure-outcome relationships. Acetaminophen exposure during pregnancy was associated with childhood asthmatic symptoms among vulnerable subgroups in this cohort. A larger study that assessed prenatal acetaminophen exposure with other social/environmental stressors and clinically confirmed outcomes is needed.

2.
Nat Prod Res ; : 1-5, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34629001

RESUMO

The objective of this work was to investigate the chemical compositions of the essential oil (EO) extracted from Senecio scandens by hydrodistillation and their insecticidal activities against Tribolium castaneum, Lasioderma serricorne and Liposceis bostrychophila. The chemical profile of the EO were analyzed by gas chromatography-mass spectrometry (GC-MS), and 20 compounds were identified which accounted for 88.03% of the total EO. Five major compounds identified in the EO were assayed against the three stored product insects. The EO showed strong contact toxicity to T. castaneum (LD50 = 18.01 µg/adult), L. serricorne (LD50 = 20.11 µg/adult) and L. bostrychophila (LD50 = 72.14 µg/cm2). Among all compounds, geraniol showed the contact toxicity against L. serricorne and L. bostrychophila with LD50 values of 15.82 µg/adult and 26.64 µg/cm2. The EO and its five chemical compounds also exhibited different level of potential repellence to the three stored product insects.

3.
Cancer Med ; 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34636145

RESUMO

BACKGROUND: The prognostic value of lactate dehydrogenase (LDH) in colorectal cancer patients has remained inconsistent between nonmetastatic and metastatic settings. So far, very few studies have included LDH in the prognostic analysis of curative-intent surgery for colorectal liver metastases (CRLM). PATIENTS AND METHODS: Five hundred and eighty consecutive metastatic colorectal cancer patients who underwent curative-intent CRLM resection from Sun Yat-sen University Cancer Center (434 patients) and Sun Yat-sen University Sixth Affiliated Hospital (146 patients) in 2000-2019 were retrospectively collected. Overall survival (OS) was the primary end point. Cox regression model was performed to identify the prognostic values of preoperative serum LDH levels and other clinicopathology variables. A modification of the established Fong CRS scoring system comprising LDH was developed within this Chinese population. RESULTS: At the median follow-up time of 60.5 months, median OS was 59.5 months in the pooled cohort. In the multivariate analysis, preoperative LDH >upper limit of normal (250 U/L) was the strongest independent prognostic factor for OS (HR 1.73, 95% confidence interval [CI], 1.22-2.44; p < 0.001). Patients with elevated LDH levels showed impaired OS than patients with normal LDH levels (27.6 months vs. 68.8 months). Five-year survival rates were 53.7% and 22.5% in the LDH-normal group and LDH-high group, respectively. Similar results were also confirmed in each cohort. In the subgroup analysis, LDH could distinguish the survival regardless of most established prognostic factors (number and size of CRLM, surgical margin, extrahepatic metastases, CEA, and CA19-9 levels, etc.). Integrating LDH into the Fong score contributed to an improvement in the predictive value. CONCLUSION: Our study implicates serum LDH as a reliable and independent laboratory biomarker to predict the clinical outcome of curative-intent surgery for CRLM. Composite of LDH and Fong score is a potential stratification tool for CRLM resection. Prospective, international studies are needed to validate these results across diverse populations.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34614353

RESUMO

The essence of Zn dendrite formation is ultimately derived from Zn nucleation and growth during the repeated Zn plating/stripping process. Here, the nucleation process of Zn has been analyzed using ex situ scanning electron microscopy to explore the formation of the initial Zn dendrite, demonstrating that the formation of tiny protrusions (the initial state of Zn dendrites) is caused by the inhomogeneity of Zn nucleation. Based on this, the uniform Zn nucleation is promoted by the Ni5Zn21 alloy coating (ZnNi) on the surface of Zn foil by electrodeposition, and the mechanism of ZnNi-promoted even nucleation is further analyzed with the assistance of density functional theory (DFT). The DFT results indicate that the ZnNi displays a stronger binding ability to Zn compared to the bare Zn, suggesting that Zn nuclei will preferentially form around ZnNi instead of continuing to grow on the surface of the initial Zn nuclei. Therefore, the designed Zn metal anode (Zn@ZnNi) can be ultra-stable for over 2200 h at a current density of 2 mA cm-2 in the symmetric cell. Even at a much higher current density of 20 mA cm-2, the extra-long life of over 2200 cycles (over 530 h) can be achieved. Moreover, the full cell with the Zn@ZnNi anode exhibits extra-long cycling performance for 500 cycles with a capacity of 207.7 mA h g-1 and 1100 cycles (148.5 mA h g-1) at a current density of 0.5 and 1 A g-1, respectively.

5.
Int J Biol Macromol ; 192: 210-218, 2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34619278

RESUMO

Schizophyllum commune (S. commune) polysaccharides are biomacromolecules with multiple biological activities and wide applications. In this study, polysaccharide production through submerged fermentation of S. commune using different surfactants was investigated. The addition of 1 g/L of polyoxyethylene sorbitan monooleate (Tween 80) at the beginning of the fermentation showed the best promotional effects on collective exopolysaccharide (EPS) production (which increased by 37.17%) while shortening the production cycle by 2 days. The monosaccharide composition of the EPS produced when the added Tween 80 was similar to that of the control; however, the molecular weight (Mw) was lower. Notably, the addition of Tween 80 significantly increased the ATP levels and the transcription levels of phosphoglucomutase and ß-glucan synthase genes in the polysaccharide synthesis pathway. The addition of Tween 80 reduced the pellet size of the mycelium compared to that of the control, but did not significantly change the microstructure of the mycelial cells. This study proposes an efficient strategy for the production of polysaccharides through submerged fermentation of S. commune, and elucidates the detailed mechanism of using Tween 80 as a fermentation stimulatory reagent.

6.
Ying Yong Sheng Tai Xue Bao ; 32(8): 2895-2905, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34664463

RESUMO

Based on the MODIS NDVI data from 2000 to 2018, we estimated the fractional vegetation cover (FVC) using the dimidiate pixel model and analyzed the spatiotemporal characteristics of FVC in the Beijing-Tianjin sand source region (BTSSR). The geographical detector model was used to estimate the impacts of natural and human factors on FVC spatial distribution at the regional scale. The results showed that the FVC of the BBTSR showed an increasing trend from 2000 to 2018, with an annual growth rate of 0.013·(10 a)-1 and a vegetation increase rate of 8.2%. The area with high FVC was concentrated in the Yanshan Mountain water source protection area, followed by the pastoral transitional zone desertified land control area and the Otindag sandy land area. The area with poor FVC was concentrated in the northern arid grassland area. The explanatory power of driving factors to FVC varied across different regions. Among the natural factors, annual precipitation was the main driving factor for the spatial distribution of FVC in the northern arid grassland area, the Otindag sandy land area and the Yanshan Mountain water source protection area. Slope was the main driving factor for the spatial distribution of FVC in the pastoral transitional zone desertified land control area. Among different human activities, the number of large livestock at the year-end was the main driving factor controlling the spatial distribution of FVC in the northern arid grassland area and the pastoral transitional zone desertified land control area, while population density was the main driving factor controlling the spatial distribution of FVC in the Otindag sandy land area and the Yanshan Mountain water source protection area. There were regional differences in the influen-ce of other factors on FVC spatial distribution. The results of the interaction detector showed that the two-factor interactions were mainly the double-synergy and nonlinear synergy. The interaction of human activities with annual precipitation and slope could more fully explain the spatial variations of FVC. The range of suitable vegetation growth identified by the risk detector was the area with annual precipitation of 316.4-486.0 mm, average relative humidity of 48.4%-57.6%, and average annual temperature of 2.5-7.9 ℃, while other driving factors were different in different zones.

7.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(4): 579-583, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34494529

RESUMO

Objective To evaluate lateral pterygoid muscle(LPM)contraction in the patients with temporomandibular disorders(TMD)based on 3D-T2 weighted imaging(3D-T2WI).Multiplanar reconstruction(MPR)was employed to measure the length of LPM in the images taken in closed-and open-mouth positions. Methods Seventeen TMD patients [age of(29.82±10.70)years,males/females=8/9] and 13 normal volunteers [control,age of(23.54±3.31)years,males/females=6/7] received 3D-T2WI of the temporomandibular joints in closed-and open-mouth positions from November 2019 to April 2020 in Department of Radiology,Hainan Hospital of Chinese PLA General Hospital.According to the position of the discs,the subjects were classified into the following groups:TMD with disc displacement without reduction(TMD-DDwoR),TMD with disc displacement with reduction(TMD-DDwR),TMD without disc displacement(TMDwoDD),and normal control without disc displacement(NCwoDD).MPR was employed to measure the maximal length of the superior belly of LPM.One-way analysis of variance,receiver operating characteristic curve,and permutation test were employed for the statistical analyses. Results The contraction of LPM was significantly shorter in TMD-DDwoR group [(3.36±1.96)mm] than in TMDwoDD group [(7.90±3.95)mm],NCwoDD group [(8.77±3.13)mm](F=12.891,P=0.000),and TMD-DDwR group[(7.12±3.69)mm](χ2=5.314,P=0.031). Conclusion This study confirmed that the contraction of LPM decreased in patients with TMD-DDwoR,which provided imaging evidence for the study of disc displacement mechanism in TMD patients.


Assuntos
Luxações Articulares , Transtornos da Articulação Temporomandibular , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Contração Muscular , Músculos Pterigoides/diagnóstico por imagem , Disco da Articulação Temporomandibular , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Adulto Jovem
8.
Zhongguo Zhong Yao Za Zhi ; 46(12): 3144-3149, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34467706

RESUMO

The effect of intestinal flora changes on the pharmacokinetics of astragaloside Ⅳ in rats with type 2 diabetes mellitus was explored in this study. The rat model in preliminary experiment was established by high-sugar and high-fat diet combined with the intraperitoneal injection of low-dose streptozotocin(STZ). Rats were divided into model group, astragaloside Ⅳ group, berberine group and combination group(five rats in each group). After two weeks of gavage, the rats' feces was taken for 16 S rRNA sequencing of intestinal flora. Pharmacokinetic experiments were performed on astragaloside Ⅳ in the four groups one day after the preliminary experiment. Plasma samples were precipitated in methanol with ginsenoside Rb_1 as an internal standard, and the plasma concentrations of astragaloside Ⅳ at different time points were determined by UPLC-MS/MS. The chromatographic separation was performed on a Waters Acquity UPLC BEH-C_(18) column(2.1 mm×100 mm, 1.7 µm) via gradient elution. The mobile phase was acetonitrile(A) and 5 mmol·L~(-1) ammonium formate solution with 0.2% formic acid(B). The flow rate was 0.4 mL·min~(-1), the injection volume 5 µL and the column temperature 40 ℃. The mass spectrometry was carried out with electrospray ionization source(ESI) in multiple reaction monitoring and positive ion modes. The specificity, linearity range, accuracy, precision, stability and dilution effect of the method all met the requirements for the determination of astragaloside Ⅳ in plasma. Plasma concentration-time curves were plotted and relevant pharmacokinetic parameters were calculated by DAS 3.2.8. The results showed that the concentration of absorbed astragaloside Ⅳ increased within 0-3.95 h and began to decline since 3.95 h. After 36 h, the metabolism was complete. The area under the plasma concentration-time curve(AUC_(0-t)) and the peak concentration(C_(max)) of astragaloside Ⅳ were increased in the three administration groups compared with the model group, but without significant difference, which suggested that the pharmacokinetic characteristics of saponin components would not necessarily change after the drug-induced alteration of intestinal flora.


Assuntos
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Saponinas , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Triterpenos
9.
Artigo em Inglês | MEDLINE | ID: mdl-34562047

RESUMO

An efficient and general radical hydroamination of alkenes using Co(salen) as catalyst, N-fluorobenzenesulfonimide (NFSI) and its analogues as both nitrogen source and oxidant was successfully disclosed. A variety of alkenes, including aliphatic alkenes, styrenes, α, ß-unsaturated esters, amides, acids, as well as enones, were all compatible to provide desired amination products. Mechanistic experiments suggest that the reaction underwent a metal-hydride-mediated hydrogen atom transfer (HAT) with alkene, followed by a pivotal catalyst controlled SN2-like pathway between in situ generated organocobalt(IV) species and nitrogen-based nucleophiles. Moreover, by virtue of modified chiral cobalt(II)-salen catalyst, an unprecedented asymmetric version was also achieved with good to excellent level of enantiocontrol. This novel asymmetric radical C-N bond construction opens a new door for the challenging asymmetric radical hydrofunctionalization.

10.
Antonie Van Leeuwenhoek ; 114(11): 1855-1865, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34468960

RESUMO

A Gram-stain-negative, aerobic, rod-shaped, non-gliding and non-motile bacterium designated as N1E253T, was isolated from marine sediments collected from the coast of Weihai, PR China. N1E253T was found to grow at pH 7.0-9.0 (optimum, pH 7.5), 15-37 °C (optimum, 30 °C) in the presence of 1.5-5.0% (w/v) NaCl (optimum, 3.0%). The major polar lipids of strain N1E253T were phosphatidylethanolamine, diphosphatidylglycerol and one unidentified phospholipid. The sole respiratory quinone was MK-9. The major cellular fatty acids (> 10.0%) were iso-C14: 0, C16: 0 and Summed Feature 3 (C16:1 ω7c and/or C16:1 ω6c). The result of the 16S rRNA gene sequence analysis confirmed the affiliation of this novel isolate to the family Verrucomicrobiaceae, with Persicirhabdus sediminis KCTC 22039 T being its closest relative with 92.1% sequence similarity. Genome sequencing revealed a genome size of 5,073,947 bp, DNA G + C content of 52.0% and two protein-coding genes related to the resistance of fluoroquinolones. Based on physiological, genomic, biochemical and chemotaxonomic characteristics, we propose that strain N1E253T represents a novel species of a novel genus within the family Verrucomicrobiaceae, for which the name Oceaniferula marina gen. nov., sp. nov. is proposed. The type strain is N1E253T (= KCTC 72800 T = MCCC 1H00405T).

11.
J Environ Manage ; 300: 113710, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509811

RESUMO

The application of green reductant is signification to recycling of cathode materials from spent lithium ions batteries. Here, ginkgo biloba was developed for enhancing leaching of spent LiNi0.6Co0.2Mn0.2O2 materials with systematically analysis of leaching kinetics and interface reaction. The leaching efficiencies of Ni, Mn, Co, and Li reach respectively 98.65 %, 98.25 %, 98.41 % and 99.99 % under optimal condition of 1.8 mol/L H2SO4 concentration, 9 g/L ginkgo biloba, 80 °C leaching temperature, 40 min time and 15 g/L pulp density. The apparent activation energies for leaching of Ni, Co, Mn and Li determined as 74.63, 79.33, 73.14 and 23.43 kJ/mol, respectively, indicates that the leaching process was controlled by the surface chemical reaction during the leaching process. Meanwhile, the regenerated material with better electrochemical performance was obtained by co-precipitation and calcination from leachate. Finally, the process is environmental friendly and economical feasible for recycling of spent lithium-ion batteries.


Assuntos
Lítio , Substâncias Redutoras , Fontes de Energia Elétrica , Cinética , Reciclagem
12.
Artigo em Inglês | MEDLINE | ID: mdl-34448583

RESUMO

Flexible optoelectronic synaptic devices that functionally imitate the neural behavior with tunable optoelectronic characteristics are crucial to the development of advanced bioinspired neural networks. In this work, amorphous oxide-decorated GaN nanowire arrays (GaOx@GaN NWAs) are prepared on flexible graphite paper. A GaOx@GaN NWA-based flexible device has tunable persistent photoconductivity (PPC) and shows a conversible fast/slow decay process (SDP). Photoconductivity can be modulated by single or double light pulses with different illumination powers and biases. PPC gives rise to the high-performance SDP such as a long decay time of 2.3 × 105 s. The modulation mechanism is proposed and discussed. Our results reveal an innovative and efficient strategy to produce decorated NWAs on a flexible substrate with tunable optoelectronic properties and exhibit potential for flexible neuromorphic system applications.

13.
Chemosphere ; 286(Pt 3): 131738, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34388437

RESUMO

The removal of toxic and harmful heavy metal contaminants from wastewater is of great importance for global environmental health. The development of efficient photocatalysts is attracting increasing interest with a current focus on material design for improved efficiency. Accordingly, this study aims to optimize the conformation of nanocomposite prepared from a CdS/ZnO heterojunction on reduced graphene oxide (RGO) for boosting the photocatalytic removal of heavy metal contaminants of aqueous systems. Under visible light, the candidate nanocomposites exhibited a range of photocatalytic activity in reducing hexavalent chromium [Cr(VI)] to trivalent chromium [Cr(III)] at room temperature. Among these different nanocomposites, the photocatalytic removal rate constant of Cr(VI) ranged as follows: ZnO/CdS6:5/RGO6 (0.106 min-1) > ZnO/CdS6:5 (0.0630 min-1) > CdS (0.0335 min-1) > ZnO (0.00121 min-1). Moreover, after five cycles of use, the photocatalytic reduction rate of ZnO/CdS6:5/RGO6 was 93.2 %, which signifies its strong re-cycling performance. These results reveal the feasibility of using CdS/ZnO6:5/RGO6 to reduce heavy metal ions from wastewater and provide insights for efficiently removing heavy metal ions without additional chemical trapping agents in the photocatalytic process.

14.
Sci Total Environ ; 802: 149869, 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34461470

RESUMO

The ratio of the perceived extent of natural sounds to the perceived extent of traffic noise in the environment has been demonstrated to be important for soundscapes, whereas research on the influence of human sounds has been limited. To examine this influence, this study proposes a human sound-based index named the red soundscape index (RSI), which is defined as the ratio of the perceived extent of human sounds to the perceived extent of other sounds. Sound pressure levels and crowd density were collected at 41 sites in 9 urban parks, and pedestrian streets in Harbin, China, and the perceived extent of various sounds was investigated by a questionnaire survey. The results confirmed a significant positive correlation between crowd density and RSI, and the A-weighted sound pressure level increased linearly with increasing RSIn (the ratio of human sounds to natural sounds) and decreased with increasing RSIt (the ratio of human sounds to traffic noises). Interestingly, the overall soundscape assessment linearly decreases with the increase in RSIn in the range of (0.8-1.5). The relationship with RSIt first shows an increase and then a decrease in a parabolic form, in which the axis of symmetry is RSIt = 2. Correspondingly, urban open spaces can be divided into three categories based on the variation trend, and different types have significant differences in overall soundscape assessment, pleasantness, and calmness. Among these, pleasantness is the highest in the sites of natural sound predominance perception. At the same time, this factor becomes the lowest in the sites of human sound predominance perception and middle in the site of balanced perception. Consequently, RSI is expected to be useful in soundscape prediction in urban open spaces.

15.
J Hazard Mater ; 422: 126912, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34416695

RESUMO

How to efficiently treat radioactive uranium-containing nuclear wastewater is one of the significant challenges to ensure the safety of nuclear technology and to avoid environmental pollution. Here we firstly prepare the metal-free 2D/2D C3N5/GO nanosheets, and customize a type-II heterojunction based on the band bending theory to achieve enhanced uranium extraction capacity via synergistic adsorption photoreduction engineering. The structure of C3N5 is explained by electron energy loss spectroscopy and synchrotron-based near-edge X-ray absorption fine structure. And C3N5 with larger π-conjugated structure expands the light response range to 747 nm, which is about 1.67 times that of C3N4. Further, we also use density functional theory to prove the existence of alternating energy levels so that photogenerated electrons could be continuously injected into the surface of GO to ensure the effective separation of electron-hole pairs and increase the material activity. The results show that the removal ratio of uranium by 2D/2D C3N5/GO heterojunction is achieved as high as 96.1% even at a low uranium concentration of 10 ppm, and reached 93.4% after exposure to gamma-ray. This work will lay a foundation for customizing the energy band structure of nonmetal-based 2D/2D nanohybrids and enriching uranium-containing wastewater through adsorption photoreduction engineering in the future.

16.
Microb Pathog ; 159: 105158, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34454025

RESUMO

BACKGROUND: Melanin is an important virulence factor for Sporothrix globosa, the causative agent of sporotrichosis, a subcutaneous mycosis that occurs worldwide. Although previous research suggests that melanin is involved in the pathogenesis of sporotrichosis, little is known about its influence on the macrophages that represent the frontline components of innate immunity. OBJECTIVES: To evaluate the effects of melanin on phagocytic activity and the expression of Toll-like receptor (TLR)2 and TLR4 during S. globosa infection of macrophages in vitro. METHODS: To compare phagocytic activity and survival rates, THP-1 macrophages and primary mouse peritoneal macrophages were co-cultured with a wild-type S. globosa strain (Mel+), an albino mutant strain (Mel-), a tricyclazole-treated Mel + strain (TCZ-Mel+), or melanin ghosts extracted from S. globosa conidia. Reactive oxygen species (ROS), nitric oxide (NO) generation, tumor necrosis factor (TNF)-α and interleukin (IL)-6 were assayed in THP-1 cells infected with S. globosa conidia. Quantitative PCR and western blotting were used to observe the effect of melanin on TLR2 and TLR4 expression. Knockdown of TLR2/4 expression with small interfering RNA was performed to further verify the role of these receptors during infection. RESULTS: Macrophages infected with Mel + conidia showed a lower phagocytosis index and a higher survival rate than TCZ-Mel+ and Mel- in vitro. After incubation with S. globosa, the release of ROS, NO, TNF-α and IL-6 by THP-1 were decreased in the presence of melanin. Increased mRNA and protein expression of TLR2 and TLR4 occurred upon S. globosa infection in THP-1, whereas the presence of melanin suppressed TLR2 and TLR4. Moreover, TLR2 or TLR4 knockdown showed a trend toward reducing the pernicious effect of S. globosa conidia on THP-1 cells in vitro. CONCLUSIONS: Collectively, our results indicated that melanin inhibits the phagocytosis of S. globosa and guards against macrophage attack by providing protection from oxygen- and nitrogen-derived radicals, as well as suppressing the host pro-inflammatory cytokine response (TNF-α and IL-6). Melanin was also involved in modulating TLR2 and TLR4 receptor expression, weakening the killing efficiency of S. globosa.


Assuntos
Sporothrix , Animais , Macrófagos , Melaninas , Camundongos , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa
17.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 37(3): 254-256, 2021 May.
Artigo em Chinês | MEDLINE | ID: mdl-34374236

RESUMO

Objective: In this study, human gastric cancer MGC-803 cells were treated with betulinic acid at different concentrations to investigate its effect on cell autophagy. Methods: The human gastric cancer MGC-803 cells were divided into 4 groups, each group was set with 3 replicate. The control group was not treated with betulinic acid, the other three groups were added with final concentration of 10,20,30 mg/L betulinic acid, respectively. Cells were treated with betulinic acid for 48 h,qRT-PCR was applied to detect the effect of betulinic acid on mRNA expressions of autophagy-related genes in human gastric cancer MGC-803 cells. Western blot was performed to determine the protein expressions of cell autophagy-related genes after drug treatment. Immunofluorescence was used to detect the localization and expression of LC3 protein in MGC-803 cells after drug treatment. Results: Compared with the control group,in the concentration range of 10~30 mg/L, the mRNA expression of LC3 and Beclin-1 in human gastric cancer MGC-803 cells treated with betulinic acid were increased significantly, the expressions of Beclin-1 and LC3-Ⅱ protein were also increased significantly, while the expression of LC3-Ⅰ protein was decreased significantly. Among them, betulinic acid at the concentration of 30 mg/L showed the best effects. In addition, betulinic acid induced the LC3 protein in MGC-803 cells to form spot aggregates in the cytoplasm. Conclusion: At the concentrations of 10~30 mg/L, betulinic acid can induce autophagy in human gastric cancer MGC-803 cells.


Assuntos
Neoplasias Gástricas , Triterpenos , Autofagia , Proteína Beclina-1/genética , Humanos , Triterpenos Pentacíclicos , Triterpenos/farmacologia
18.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 37(3): 257-261, 2021 May.
Artigo em Chinês | MEDLINE | ID: mdl-34374237

RESUMO

Objective: To investigate the effect of betulinic acid on the proliferation of human gastric cancer MGC-803 cells in vitro. Methods: Human gastric cancer MGC-803 cells were divided into 4 groups, each with 3 multiple holes. Control cells add betulinic acid at a concentration of 0 µg /ml, and the other three experimental groups were added with final concentration of 10, 20, 30 µg/ml Betulinic acid respectively. Cells in each group were incubated in a 5% CO2 incubator for 48 hours, and the Giemsa staining method and trypan blue exclusion method were used to detect the effect of betulinic acid on the cell clone formation rate and growth inhibition rate; EdU method and flow cytometry were used to detect cell proliferation and cell cycle changes; qRT-PCR and Western blot were used to detect the expressions of cell cycle regulators CCNB1 and CCND1. Results: Compared with the control group, the clone formation rate of human gastric cancer MGC-803 cells was significantly reduced (P<0.01), the growth inhibition rate was significantly increased, and the cell proliferation ability was significantly decreased (P<0.01); with the increase of betulinic acid concentration in each experimental group the proportion of cells in the G1 phase was gradually decreased, and the number of cells in S phase was increased significantly (P<0.01); the mRNA and protein expression levels of cell cycle regulators CCNB1 and CCND1 were decreased significantly, and the 30 µg/ml betulinic acid treatment group performed best. Conclusion: At a final concentration of 10~30 µg/ml, betulinic acid can reduce the proliferation of human gastric cancer MGC-803 cells, inhibit cell growth, and down-regulate the expression of CCNB1 and CCND1 to block human gastric cancer MGC-803 cells in the S phase.


Assuntos
Neoplasias Gástricas , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Triterpenos Pentacíclicos
19.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 37(4): 419-422, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34374264

RESUMO

Objective: The effects of betulinic acid (BA) on apoptosis of human gastric cancer MGC-803 cells was investigated by using human gastric cancer MGC-803 cells as experimental materials, and the basis for its clinical application was provided. Methods: The human gastric cancer MGC-803 cells were divided into 4 groups,each group was set with 3 replicates.The control group was MGC-803 cells without being added betulinic acid; the other 3 groups of experimental groups were treated with betulinic acid at final concentrations of 10, 20 and 30 µg /ml respectively. Cells were treated with betulinic acid of different concentrations for 48 h. Laser confocal microscope was used to observe morphological changes of MGC-803. The activities of Caspase-3 and Caspase-9 were detected by an assay kit. Flow cytometry was applied to determine mitochondrial membrane potential. The mRNA and protein levels of Caspase-3, Caspase-9 and Cyt c were also detected by qRT-PCR and Western blot, respectively. Results: Compared with the control group, the activities of Caspase-3 and caspase-9 were increased(P<0.01), while the mitochondrial membrane potential was decreased significantly(P<0.01). The mRNA and protein expressions of Caspase-3, caspase-9 and Cyt c were up-regulated significantly(P<0.01). Conclusion: In the final concentration range of 10 ~ 30 µg/ml, betulinic acid can induce apoptosis of human gastric cancer MGC-803 cells by regulating the expression of Caspase-3, Caspase-9 and Cyt c.


Assuntos
Neoplasias Gástricas , Apoptose , Caspase 3/genética , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Triterpenos Pentacíclicos , Neoplasias Gástricas/tratamento farmacológico
20.
Phytochemistry ; 190: 112890, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34388480

RESUMO

Undescribed phloroglucinol derivatives, rhotomensones A-G, and a known derivative rhodomyrtosone B, were isolated from the leaves of Rhodomyrtus tomentosa. Rhotomensones A-D and G have unreported structural characteristics, in which rhotomensone A substitutes a benzene ring, rhotomensones B-D are bonded with a 2-methylbutanoyl group, and rhotomensone G has two fewer carbons. The structures of these compounds were determined by NMR spectroscopy, circular dichroism (CD) spectroscopy and X-ray crystallography. The inhibitory activities against α-glucosidase of rhotomensones E and F were evaluated in vitro, with IC50 values of 0.50 ± 0.14 mg/mL and 0.07 ± 0.02 mg/mL. Moreover, rhodomyrtosone B showed significant antibacterial activity against some bacteria, with MIC values ranging from 0.50 to 16.00 µg/mL.


Assuntos
Myrtaceae , Floroglucinol , Antibacterianos/farmacologia , Floroglucinol/farmacologia , Extratos Vegetais , Folhas de Planta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...