Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 112
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Am J Bot ; 2020 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-32227348

RESUMO

PREMISE: Unique among vascular plants, some species of Selaginella have single giant chloroplasts in their epidermal or upper mesophyll cells (monoplastidy, M), varying in structure between species. Structural variants include several forms of bizonoplast with unique dimorphic ultrastructure. Better understanding of these structural variants, their prevalence, environmental correlates and phylogenetic association, has the potential to shed new light on chloroplast biology unavailable from any other plant group. METHODS: The chloroplast ultrastructure of 76 Selaginella species was studied with various microscopic techniques. Environmental data for selected species and subgeneric relationships were compared against chloroplast traits. RESULTS: We delineated five chloroplast categories: ME (monoplastidy in a dorsal epidermal cell), MM (monoplastidy in a mesophyll cell), OL (oligoplastidy), Mu (multiplastidy, present in the most basal species), and RC (reduced or vestigial chloroplasts). Of 44 ME species, 11 have bizonoplasts, cup-shaped (concave upper zone) or bilobed (basal hinge, a new discovery), with upper zones of parallel thylakoid membranes varying subtly between species. Monoplastidy, found in 49 species, is strongly shade associated. Bizonoplasts are only known in deep-shade species (<2.1% full sunlight) of subgenus Stachygynandrum but in both the Old and New Worlds. CONCLUSIONS: Multiplastidic chloroplasts are most likely basal, implying that monoplastidy and bizonoplasts are derived traits, with monoplastidy evolving at least twice, potentially as an adaptation to low light. Although there is insufficient information to understand the adaptive significance of the numerous structural variants, they are unmatched in the vascular plants, suggesting unusual evolutionary flexibility in this ancient plant genus.

2.
Hepatol Int ; 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32130674

RESUMO

BACKGROUND: Hepatitis B is a serious global health problem. Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a major risk factor in the endemicity of HBV infection. Oral antiviral drugs are recommended to highly viremic mothers to decrease MTCT of HBV. The present network analysis compared the efficacy of available treatments to prevent the MTCT of HBV. METHODS: The electronic databases of PubMed, Embase, Web of Science, Scopus, and Wanfang data were searched for eligible studies. Pair-wise meta-analysis and Bayesian network analysis were applied to compare the efficacy of antiviral drugs. RESULTS: Seventy-five studies involving 12,740 pregnant females were eligible for analysis. On pair-wise analysis, lamivudine (OR 0.15, 95% CI 0.09-0.25, I-squared = 0%), telbivudine (OR 0.07, 95% CI 0.05-0.10, I-squared = 0%) and tenofovir (OR 0.07, 95% CI 0.04-0.13, I-squared = 0%) significantly decreased the MTCT rate. Results of multiple comparisons with ranking probability based on Bayesian analysis showed that tenofovir (SUCRA = 96.83%) appeared more effective than the two other drugs. CONCLUSION: In addition to active and passive immunoprophylaxis, lamivudine, telbivudine and tenofovir in highly viremic mothers can further decrease MTCT of HBV. Based on direct and indirect evidence, tenofovir appears to be more effective than the two other drugs in the prevention of HBV MTCT.

3.
Int J Surg ; 76: 153-162, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32169568

RESUMO

BACKGROUND: It remains uncertain whether there is a benefit to perioperative beta-blocker use on outcomes after non-cardiac surgery. This meta-analysis aims to update the evidence regarding the associations between beta-blocker exposure and patient major short-term outcomes following non-cardiac surgery. METHODS: Pubmed, Embase, and the Cochrane Central Register from their inception to May 2019 were searched by two independent authors. Observational studies reporting associations between perioperative beta-blocker treatment and short-term outcomes including 30-day all-cause mortality (ACM), 30-day major adverse cardiovascular events (MACE) and 30-day stroke risk were selected for inclusion. Meta-analyses were carried out by using random effects models. RESULTS: Nineteen studies with a total of 1,711,766 participants were identified. Beta-blocker exposure was associated with reduced 30-day all-cause mortality (ACM) (RR 0.83, 95% CI 0.72 to 0.96). No evidence of publication bias was observed. Subgroup analyses revealed that significant 30-day survival benefits were observed in prospective, population-based studies, drug exposure period last till 1-2 months after surgery, patients having abdominal gastrointestinal surgery or having 3-4 cardiac risk factors. Beta-blocker exposure was associated with increased 30-day ACM among patients with no cardiac risk factors (RR 1.30, 95% CI 1.19 to 1.43). However, meta-analysis demonstrated a non-significant risk reduction in 30-day MACE (RR 1.03; 95% CI 0.85 to 1.25) or 30-day stroke risk (RR 0.86; 95% CI 0.44 to 1.68) with beta-blocker exposure. CONCLUSIONS: The results of the current meta-analysis indicate beta-blocker exposure may be a significant indicator for 30-day ACM, but not for 30-day MACE or 30-day stroke risk. The association between beta-blocker exposure and long-term outcomes deserves further investigation.

4.
Cancer Med ; 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32064753

RESUMO

MicroRNAs(miRNAs) are maladjusted in multifarious malignant tumor and can be considered as both carcinogens and tumor-inhibiting factor. In the present study, we analyzed the miRNAs expression profiles and clinical information of 481 patients with head and neck squamous cell carcinoma (HNSCC) through the TCGA dataset to identify the prognostic miRNAs signature. A total of 114 significantly differentially expressed miRNAs (SDEMs) were identified, consisting of 60 up-adjusted and 54 down-adjusted miRNAs. The Kaplan-Meier survival method identified the prognostic function of 2 miRNAs (miR-4652-5p and miR-99a-3P). Univariate and multivariate Cox regression analyses indicated that the 2 miRNAs were significant prognostic elements of HNSCC. Furthermore, bioinformatic analysis was conducted by means of 4 online gene predicted toolkits to recognize the target genes, and enrichment analysis was performed on the target genes by DAVID. The outcomes depicted that target genes were correlated with calcium, as well as cell proliferation, circadian entrainment, EGFR, PI3K-Akt-mTOR, and P53 signaling pathways. Finally, the PPI network was conducted in view of STRING database and Cytoscape. Eight hub genes were identified by CytoHubba and MCODE app, respectively, CBL, SKP1, H2AFX, HGF, POLR2F, UBE2I, VAMP2, and GNAI2 genes. As a result, we identified 2 miRNAs signatures, 8 hub genes, and significant signaling pathways for estimating the prognosis of HNSCC. In order to further explore the molecular mechanism of HNSCC occurrence and development, more comprehensive basic and clinical studies are needed.

5.
J Dairy Sci ; 103(3): 2731-2742, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954568

RESUMO

It was previously thought that the Panton-Valentine leukocidin (PVL) toxin of Staphylococcus aureus (S. aureus) was not the main cause of cow mastitis. However, in recent years, detection of the gene encoding PVL has been increasing in dairy cow mastitis, which implies that PVL may be related to bovine mastitis. Therefore, we wanted to search for drugs inhibiting PVL or PVL-induced apoptosis. In this report, we investigated the apoptosis mechanism of PVL in bovine mammary epithelial cells (BMEC) and the inhibition mechanism of matrine and baicalin on PVL-induced apoptosis of BMEC. The results demonstrated that BMEC were damaged and underwent apoptosis by a standard PVL-producing strain of S. aureus (ATCC 49775), a PVL knockout mutant Δpvl 49775, complemented mutant C-Δpvl 49775, or recombinant (r)PVL in vitro. The rates of apoptosis and necrosis induced by S. aureus ATCC 49775 and C-Δpvl 49775 were significantly higher than those induced by Δpvl 49775, demonstrating that BMEC apoptosis and necrosis were associated with PVL. In addition, this research found matrine and baicalin could inhibit the apoptosis of BMEC induced by PVL-producing S. aureus and by rPVL. Matrine downregulated protein expression levels of endogenous and exogenous cleaved caspase-3, cleaved caspase-8, and cleaved caspase-9, and the effect was pronounced at a concentration of 50 µg/mL. Baicalin downregulated the expression of cleaved caspase-9. These results suggested that matrine and baicalin may have potential value against cow mastitis caused by the toxin PVL.

6.
Huan Jing Ke Xue ; 40(12): 5493-5502, 2019 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854622

RESUMO

While the effect of increasing tidewater inundation caused by sea-level rise on carbon cycling had been well studied in saltmarshes, little is known about the effect of increasing tidewater inundation on CO2 and CH4 effluxes in the tidal freshwater marsh soils. Herein, the effects of tide inundation on porewater geochemistries (NH4+, NO3-, DOC, dissolved CH4, and DIC) and CH4 and CO2 effluxes were examined in the soils of tidal freshwater marshes in the Minjiang River Estuary, East China Sea. By applying "mesocosm" and a simulated tide pool, the tide inundation height increased by 15 cm and 30 cm over the control (CK). The CO2 effluxes decreased by 28.53% and 36.56%, and the dissolved CH4 concentrations increased by 47.83% and 73.91%, in treatments (CK+15 cm) and (CK+30 cm), respectively. The CH4 effluxes did not change significantly in the treatment (CK+15 cm), but increased by 29.27% in treatment (CK+30 cm). The increasing tidewater inundation had no significant impact on DOC concentrations, but increased NH4+ concentrations and decreased DIC and NO3- concentrations. Increasing tide inundation also reduced the temperature sensitivity of CH4 and CO2 effluxes. The study highlighted that the sea level rise-induced increase in tidewater inundation would decrease the annual global warming potential of tidal freshwater wetlands by 28% and 35% in the next 50 and 100 years, respectively.

7.
Huan Jing Ke Xue ; 40(6): 2631-2638, 2019 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854654

RESUMO

Microplastics (MPs, plastic fibers, debris, or particles that are generally smaller than 5 mm in diameter) can serve as carriers for hazardous substances, which are ingested by organisms in the ocean and can affect their growth and metabolism. Moreover, MPs will spread with ocean currents, and MP pollution has become a global problem. In this study, the MP abundance distribution of four typical beaches near the coast of Qingdao was studied by the combination of ordinary microscope and fluorescence microscope methods. In addition, the distribution of MPs collected from various beaches in different particle size ranges, shapes, and chemical compositions was discussed. Abundances on the sea surface varied between 5.05×103 particles·m-3 and 1.25×104 particles·m-3, and the concentration of MPs in sand varied between 1.91×103 particles·m-2 and 4.35×103 particles·m-2, with no significant differences detected among the four beaches examined. The results show the pervasiveness of MP pollution in coastal environments of Qingdao. The size of particles found in this study ranged from 5 mm to 50 µm, and increases in abundance were detected with the decreasing particle size. Polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), 96% polystyrene+4% butadiene copolymer (SB), polymethyl acrylate (PMA), and polyamide (PA) were present in seawater in coastal environments of Qingdao, and compared with the seawater samples, no PA or PMA were found in sand. Research results indicated that fiber was dominant in seawater and sand. MPs in the sand were similar to those in seawater in terms of the particle size, shape, and composition, thus indicating that the seawater and sand of the bathing beaches in Qingdao may have the same pollution sources, e. g., the packaging industry, clothing textile industry, and tourism. This paper studies the distribution and sources of MPs in the bathing beaches of Qingdao, and it provides basic data for research and supervision of environmental MP pollution in Chinese coastal zones.

8.
Gastrointest Endosc ; 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31738926

RESUMO

BACKGROUND AND AIMS: Studies comparing the diagnostic efficacy of liquid-based cytology (LBC) and smear cytology (SC) of pancreatic tissue sampling obtained via EUS-guided FNA (EUS-FNA) are still insufficient, mainly because results were controversial. We compared the diagnostic efficiency of LBC and SC of EUS-FNA of pancreatic lesions in one of the largest tertiary hospitals in China. METHODS: A retrospective database search (January 2015 to January 2019) was performed for patients who underwent EUS-FNA with both LBC and SC. Demographic, cytologic, and endosonographic data were collected from 819 patients; 514 cases met the inclusion criteria. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were compared. Rapid on-site evaluation was not available in all cases. RESULTS: Three hundred eighty-five cases (74.90%) had confirmed malignancy, and 40 cases (7.78%) confirmed benign neoplasm. Adequate tissue sampling rates showed no significant difference between the 2 groups. The sensitivity, accuracy, and negative predictive value (NPV) of LBC were higher than those of SC with statistical significance (71.4% vs 55.1%, 76.1% vs 61.6%, and 40.6% vs 27.7%, respectively). The sensitivity, accuracy, and NPV of combined SC and LBC were higher than those of LBC alone with statistical significance (83.9% vs 71.4%, 86.5% vs 76.1%, and 56.8% vs 40.6%, respectively). Multivariate analysis revealed that pancreatic neck/body/tail lesions (P = .003), solid lesions (P < .001), 22-gauge needle size (P < .001), and number of needle passage >3 (P = .041) were associated with higher diagnostic sensitivity in all participants using LBC, whereas number of needle passage >3 (P = .017) was associated with higher diagnostic sensitivity using SC. CONCLUSIONS: LBC was more accurate and sensitive than SC in EUS-FNA of pancreatic lesions with higher NPV when rapid on-site evaluation is unavailable. Pancreatic neck/body/tail lesions, solid lesions, 22-gauge needle, and more than 3 passes were associated with higher sensitivity when using LBC. Performing more than 3 passes is associated with higher sensitivity when using SC.

9.
Inorg Chem ; 58(19): 13360-13369, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31503468

RESUMO

The detection of hypochlorite (ClO-) content in tap water is extremely important because excess amounts of hypochlorite can convert into highly toxic species and inadequate amounts of hypochlorite cannot fully kill bacteria and viruses. Although several metal-organic frameworks (MOFs) have been successfully employed as fluorescent sensors for hypochlorite detection, all these sensors are based on single emission that responds to the dose of hypochlorite. Ratiometric sensors are highly desirable, which can improve the sensitivity, accuracy, and reliability via self-calibration. Herein, a nanoscale dual-emission multivariate 5-5-Eu/BPyDC@MOF-253-NH2 was synthesized by sequential mixed-ligand self-assembly and postsynthesis method. Among the two emission bands of 5-5-Eu/BPyDC@MOF-253-NH2, the strong blue emitting derived from ligands is sensitive to hypochlorite, while the red emitting derived from Eu(III) almost keeps invariable. Therefore, 5-5-Eu/BPyDC@MOF-253-NH2 was exploited as a fluorescent ratiometric nanosensor for "on-off" sensing of hypochlorite. Notably, the proposed sensing system showed an excellent performance including fast response (within 15 s), relative high specificity, wide linear range (0.1-30 µM), and low detection limit (0.094 µM). Besides, the suppressed blue emitting was recovered after the addition of ascorbic acid (AA) that consumes ClO- via the redox reaction. Therefore, 5-5-Eu/BPyDC@MOF-253-NH2 was further employed as a fluorescent ratiometric nanosensor for the "on-off-on" sensing of AA. This work represents the first MOF-based fluorescent "switch" for the ratiometric sensing of hypochlorite and the second for ratiometric sensing of AA.

10.
Bioorg Med Chem ; 27(20): 115051, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31492532

RESUMO

The pyrimidine-2,4-diamine analogs exerted excellent activities in down-regulation of ALK phosphorylation. However, the prevalent drug-resistant site-mutation has gradually prevented the agents from being widely used. Herein, we conducted an exploration of high affinity moiety that bound to the solvent-front region (G1202R located) within the ATP binding site of ALK leading to the synthesis of thirty-five pyrimidine-2,4-diamine derivatives. Among these compounds, urea group was extensively derivatized which finally resulted in the identification of the 'semi-free urea' compound 39. All compounds were assayed cytotoxicity and enzymatic activities and 39 turned out to be the most potent one with IC50 values of 2.1, 0.91, 4.3 and 0.73 nM towards ALKwt, ALKL1196M, ALKG1202R and ROS1, respectively. The performances of 39 on ALK- & ROS1-dependent cell lines were in good accordance with enzymatic activities with IC50 values below 0.06 µM. Besides, 39 induced cell apoptosis in a dose-dependent manner in H2228 cells. Finally, the binding models of 39 with ALKwt, ROS1, ALKL1196M and ALKG1202R were ideally established which further clearly elucidated their mode of action within the active site.

11.
Bioorg Med Chem ; 27(18): 4089-4100, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31378597

RESUMO

Aiming to develop potent JAK inhibitors, two series of 4-(1H-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidine derivatives (8a-8p and 11a-11i) were designed and synthesized by coalescing various N-acylpiperidine motifs with baricitinib. The pharmacological results based on enzymatic and cellular assays identified the optimized compound 11e, which exerted over 90% inhibition rates against JAK1 and JAK2, and displayed the most compelling anti-inflammatory efficacy superior to baricitinib by inhibiting NO generation from LPS-induced RAW264.7 macrophages. Importantly, low cytotoxity of 11e was revealed by the IC50 value of 88.2 µM against normal RAW264.7 cells. The binding mode of 11e with JAK1 and JAK2 identified the essential structural bases in accord with SARs analysis. Furthermore, cellular morphology observation and western blot analysis disclosed the ability of 11e to relieve cells inflammatory damage by significantly down-regulating LPS-induced high expression of JAK1, JAK2, as well as pro cytokine IL-1ß. Together, 11e was verified as a promising lead for JAK inhibitors for the treatment of inflammatory diseases.

12.
Microb Pathog ; 136: 103698, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31470047

RESUMO

Quorum sensing (QS) mediates the coordination of population-based behavior in bacteria, which is highly involved in the formation of bacterial biofilms and virulence of bacteria in vivo. Therefore, an inhibition of QS and biofilm growth is of therapeutic interest. This study exhibited the an auto-inducer molecule (AI-2) activity as the most important component of the QS system was positively correlated with the growth and biofilm formation of S. epidermidis strains. In addition, TASA and matrine have a capacity to inhibit AI-2 in three S. epidermidis strains compared to the control (p < 0.01). This result indicated TASA and matrine can also decrease AI-2 activity in the biofilm of S. epidermidis (p < 0.05). By comparison, TASA was more effective than ceftazidime and matrine to inhibit the AI-2 activity in biofilm S.epidermidis reference strain ATCC35984 (p < 0.05). This result indicated potentials of TCM compounds TASA and matrine in prevention of biofilm formation in Staphylococcus epidermidis infections.

13.
Yi Chuan ; 41(7): 653-661, 2019 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-31307974

RESUMO

RNA interference is a gene silencing phenomenon mediated by short double-stranded RNAs, which has become a widely used research technology for reverse genetics. In order to make students understand the technology better, the students were required to select target genes, to design small interfering RNAs (siRNAs) and primers, and then to test the effect of gene silencing mediated by siRNAs. Taking the fifth group in 2018 as an example, Mus musculus acyl-CoA synthetase long-chain family member 1 (Acsl1) was selected as the target gene, two pairs of siRNAs targeting Acsl1 mRNA were designed and transfected into 3T3-L1 by electroporation, then the total RNAs were extracted and synthesized to cDNA, and the expression levels of mRNAs were finally tested by relative quantitative PCR. The results showed that both pairs of siRNAs had more than 60% silencing effects. In the past three years, about 83% of the students completed all the experiments successfully and screened out at least a pair of effective siRNA. This teaching practice for undergraduates enhances students' understanding of RNA interference principle and technology, and exercises students' lab experience and scientific research ability.


Assuntos
Genética/educação , Interferência de RNA , Estudantes , Ensino , Animais , Coenzima A Ligases , Expressão Gênica , Humanos , Camundongos , RNA Interferente Pequeno
14.
J Nanosci Nanotechnol ; 19(12): 8135-8142, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196336

RESUMO

Precisely controlled dimensions of heterostructured ZnO nanorod arrays were grown on micropatterned Au films supported by Si substrate using chemical vapor deposition (CVD). The field emission properties were attributed to pointed nanorods, thickness of catalyst, preferential growth, density, morphology of ZnO and Molybdenum (Mo) decorated ZnO nanorod arrays (Mo/ZnO). The selective restrained heterostructure approach resulted in excellent control over periodicity, location and density of ZnO nanorod arrays. Overall, field emission properties of bare ZnO nanorod arrays showed a low turn-on field of ~4.7 V/µm and a high field enhancement factor (ß) ~1686 to 7.3 V/µm and (ß) ~807 for Mo/ZnO. It was also found that the field emission properties were significantly influenced by densely decorated Mo nanoparticles on as-grown ZnO nanorod arrays.

15.
Huan Jing Ke Xue ; 40(4): 1788-1796, 2019 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-31087920

RESUMO

Overlying water from the tidal marshes in five estuaries and bays, namely, Xinghua Bay (Fuzhou Part), Fuqing Bay, Luoyuan Bay, Minjiang River Estuary, and Aojiang River Estuary of the Fuzhou region were collected in autumn of 2015, and the nitrogen and phosphorus nutrient concentration and other physical and chemical indicators of the overlying water were measured to discuss the reasons for the differences in the nutrient concentration of the overlying water in tidal marsh wetlands in different bays and estuaries. There were significant differences in the nitrogen and phosphorus nutrient concentrations of the overlying waters of the tidal marshes in the different bays and estuaries (P<0.05). The concentrations of nitrogen and phosphorus in Fuqing Bay were relatively high, while Xinghua Bay had the lowest nitrogen nutrient concentration and Aojiang River Estuary had the lowest phosphorus nutrient concentration. The nutrient concentration of the overlying water in Fuqing Bay is mainly affected by regional aquaculture, land-source pollution, and topography, while that in Xinghua Bay is mainly affected by tides. The vegetation type had an effect on the nutrient concentration of the overlying water in the wetlands. The concentration of nitrogenous nutrients in the overlying water of the marsh wetland in the Suaeda australis community was relatively high, while the nitrogen and phosphorus nutrient concentrations in the overlying water of the Spartina alterniflora community wetland was relatively low; the concentrations of nutrients in the overlying water of different plant communities in the same bay or estuary marsh wetland were different, and the relationships were complex. Tides, surface runoff, plant communities, topography, and human activities all had an important impact on the nutrient concentrations in the overlying waters of the bay and estuary wetlands.

16.
Huan Jing Ke Xue ; 40(1): 164-171, 2019 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-30628272

RESUMO

Components of chromophoric dissolved organic matter (CDOM) from eight coastal land-based shrimp ponds in the Minjiang, Mulan, and Jiulong rivers of subtropical southeastern China were determined by fluorescence excitation emission matrix spectroscopy combined with parallel factor analysis (EEMs-PARAFAC). Four separate fluorescence components, including two protein-like components (C1, C4) and two humic-like components (C2, C3), were identified as the dominant components of the CDOM in these shrimp ponds. The fluorescence indices (FI, BIX, and HIX) suggest that the CDOM of shrimp ponds shows low humification and is mainly derived from spontaneous sources. The protein-like and humic-like components have similar sources and exhibit a similar geochemical behavior. The salinity is negatively correlated with all CDOM fractions, whereas the DOC concentrations show only a positive correlation with the humic fractions of the CDOM. This study provides a scientific basis for the photochemical properties of CDOM in shrimp ponds.


Assuntos
Aquicultura , Compostos Orgânicos/análise , Tanques/química , Animais , China , Estuários , Análise Fatorial , Espectrometria de Fluorescência
17.
Bot Stud ; 60(1): 1, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30617933

RESUMO

BACKGROUND: Ice plant (Mesembryanthemum crystallinum L.) is a model plant for studying salt-tolerant mechanisms in higher plants. Many salt stress-responsive ice plant genes have been identified with molecular and biochemical approaches. However, no further functional characterization of these genes in host plant due to lack of easy and effective transformation protocols. RESULTS: To establish efficient transformation system of ice plants, three types of ice plant materials, hypocotyl-derived callus, aseptically-grown seedlings and pot-grown juvenile plants, were used to develop Agrobacterium-mediated transformation protocols. The highest transient transformation efficiency was with 5-day-old ice plant callus co-incubated with an Agrobacterium tumefaciens at 2.5 × 109 cells mL-1 for 48 h. The 3-day-old ice plant seedlings with root tip removed were successfully infected with A. tumefaciens or A. rhizogenes, and obtained 85% and 33-100% transient transformation rates, respectively. The transient transformation assays in ice plant callus and seedlings demonstrated that the concentrations of Agrobacteria, the durations of co-incubation time, and the plant growth stages were three important factors affecting the transient transformation efficiencies. Additionally, pot-grown juvenile plants were syringe-injected with two A. rhizogenes strains A8196 and NCPPB 1855, to establish transformed roots. After infections, ice plants were grown hydroponically and showed GUS expressions in transformed roots for 8 consecutive weeks. CONCLUSIONS: Our Agrobacterium-mediated transformation protocols utilized hypocotyl-derived callus and seedlings as plant materials, which can be easily obtained in large quantity. The average successful transient transformation rates were about 2.4-3.0% with callus and 33.3-100.0% with seedlings. We also developed a rapid and efficient protocol to generate transgenic roots by A. rhizogenes infections without laborious and challenging tissue culture techniques. This protocol to establish composite ice plant system demonstrates excellent improvements in efficiency, efficacy, and ease of use over previous ice plant transformation protocols. These Agrobacterium-mediated transformation protocols can be versatile and efficient tools for exploring gene functions at cellular and organ levels of ice plants.

18.
Biomed Res Int ; 2018: 7356173, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30327780

RESUMO

Diabetes has become the third most serious threat to human health, after cancer and cardiovascular disease. Notably, Lactobacillus brevis is the most common species of LAB that produces γ-aminobutyric acid (GABA). The aim of this study is to clarify the effect of time, strain types, antibiotic concentrations, different levels of pH, and intestinal juices in aerobic or anaerobic conditions and the effect of interactions between these factors on the potential properties of KLDS 1.0727 and KLDS 1.0373, furthermore, antagonistic activity against foodborne pathogens. Moreover, another aim is to study the capability of KLDS 1.0727 and KLDS 1.0373 strains as gad gene carriers to express GABA that reduce the risk of type 1 diabetes in C57BL/6 mice as diabetic models. The obtained results exhibited the surprising tolerance of Lactobacillus brevis strains in vitro digestion models mimicking the conditions of the gastrointestinal tract, further, large antagonistic activity against foodborne pathogeneses. In vivo results displayed the significant effect on glucose level reduction, blood plasma, and histological assays of mice organs. As recommended, the use of Lactobacillus brevis strains should be widely shared in the market as a natural source of GABA in pharmaceutical and food applications.


Assuntos
Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 1/terapia , Lactobacillus brevis , Probióticos/farmacologia , Animais , Células CACO-2 , Diabetes Mellitus Experimental/microbiologia , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/microbiologia , Diabetes Mellitus Tipo 1/patologia , Humanos , Lactobacillus brevis/genética , Lactobacillus brevis/crescimento & desenvolvimento
19.
Molecules ; 23(8)2018 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-30104528

RESUMO

Many studies have demonstrated that berberine inhibited the cell migration and invasion in human cancer cell lines. However, the exact molecular mechanism of berberine inhibiting the cell migration and invasion of human melanoma A375.S2 and A375.S2/PLX (PLX4032 induced resistant A375.S2) skin cancer cells remains unknown. In this study, we investigated the anti-metastasis mechanisms of berberine in human melanoma cancer A375.S2 cells and A375.S2/PLX resistant cells in vitro. Berberine at low concentrations (0, 1, 1.5 and 2 µM) induced cell morphological changes and reduced the viable cell number and inhibited the mobility, migration, and invasion of A375.S2 cells that were assayed by wound healing and transwell filter. The gelatin zymography assay showed that berberine slightly inhibited MMP-9 activity in A375.S2 cells. Results from western blotting indicated that berberine inhibited the expression of MMP-1, MMP-13, E-cadherin, N-cadherin, RhoA, ROCK1, SOS-1, GRB2, Ras, p-ERK1/2, p-c-Jun, p-FAK, p-AKT, NF-κB, and uPA after 24 h of treatment, but increased the PKC and PI3K in A375.S2 cells. PLX4032 is an inhibitor of the BRAFV600E mutation and used for the treatment of cancer cells harboring activated BRAF mutations. Berberine decrease cell number and inhibited the cell mobility in the resistant A375.S2 (A375.S2/PLX, PLX4032 generated resistant A375.S2 cells). Based on these observations, we suggest that the potential of berberine as an anti-metastatic agent in melanoma that deserves to be investigated in more detail, including in vivo studies in future.


Assuntos
Berberina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Quinase 1 de Adesão Focal/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Humanos , Metaloproteinases da Matriz/metabolismo , Melanoma/metabolismo , Melanoma/patologia , Metástase Neoplásica
20.
Huan Jing Ke Xue ; 39(1): 300-309, 2018 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965696

RESUMO

Annual drainage is a typical management activity practiced by operators as a way to export aquaculture effluent, accelerate aerobic decomposition of bottom soils, and avoid eutrophication during the non-culture period after harvest. Drainage activities can cause large changes in hydrology, nutrient cycling, sediment physicochemical properties, and even broad ecosystem functions. In order to understand the effects of drainage on the diurnal variation characteristics and magnitude of greenhouse gas (CH4 and N2O) fluxes from the aquaculture ponds of the estuaries, a 24-hour continuous monitoring was conducted from one undrained pond (UDP) and one drained pond (DP) during early winter in the Minjiang River estuary on the southeast coast of China. Over the entire study period, the fluxes of CH4 from the UDP and DP ranged from 0.04 to 0.10 mg·(m2·h)-1 and 14.04 to 33.72 mg·(m2·h)-1, respectively, with means of (0.07±0.01) mg·(m2·h)-1 and (24.74±2.33) mg·(m2·h)-1. The CH4 flux was lower during the day and higher at night with a net flux as the sources of the CH4. The fluxes of N2O from the UDP ranged from -0.027 to 0.011 mg·(m2·h)-1, and the average fluxes of (0.002±0.004) mg·(m2·h)-1 showed "weak absorption by day and emission at night." The N2O fluxes from the DP were emitted all day (ranging from 0.59 to 1.76 mg·(m2·h)-1) with the average fluxes of N2O (1.07±0.15) mg·(m2·h)-1 indicating higher fluxes at night and lower fluxes during the day. Our research demonstrated that drainage would significantly enhance CH4 and N2O release from the aquaculture ponds. The study also preliminarily confirms that the undrained pond converted to a drained pond considerably alter the diurnal variation characteristics of the CH4 and N2O emissions during early winter. Clearly, future measurements in situ at high frequency over a long time and at different spatial scales would be worth researching from drained aquaculture ponds.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA