排序方式: 共有47条查询结果,搜索用时 304 毫秒
11.
12.
Secondary Metabolites Produced by the Marine Bacterium Halobacillus salinus That Inhibit Quorum Sensing-Controlled Phenotypes in Gram-Negative Bacteria
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Margaret E. Teasdale Jiayuan Liu Joselynn Wallace Fatemeh Akhlaghi David C. Rowley 《Applied microbiology》2009,75(3):567-572
Certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. Here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. Isolate C42, a Halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by Vibrio harveyi in cocultivation experiments. With the use of bioassay-guided fractionation, two phenethylamide metabolites were identified as the active agents. The compounds additionally inhibit quorum sensing-regulated violacein biosynthesis by Chromobacterium violaceum CV026 and green fluorescent protein production by Escherichia coli JB525. Bacterial growth was unaffected at concentrations below 200 μg/ml. Evidence is presented that these nontoxic metabolites may act as antagonists of bacterial quorum sensing by competing with N-acyl homoserine lactones for receptor binding. 相似文献
13.
Sajjad Salari Maedeh Ghasemi Javad Fahanik-Babaei Reza Saghiri Remy Sauve Afsaneh Eliassi 《PloS one》2015,10(5)
We report in a previous study the presence of a large conductance K+ channel in the membrane of rough endoplasmic reticulum (RER) from rat hepatocytes incorporated into lipid bilayers. Channel activity in this case was found to decrease in presence of ATP 100 µM on the cytoplasmic side and was totally inhibited at ATP concentrations greater than 0.25 mM. Although such features would be compatible with the presence of a KATP channel in the RER, recent data obtained from a brain mitochondrial inner membrane preparation have provided evidence for a Maxi-K channel which could also be blocked by ATP within the mM concentration range. A series of channel incorporation experiments was thus undertaken to determine if the ATP-sensitive channel originally observed in the RER corresponds to KATP channel. Our results indicate that the gating and permeation properties of this channel are unaffected by the addition of 800 nM charybdotoxin and 1 µM iberiotoxin, but appeared sensitive to 10 mM TEA and 2.5 mM ATP. Furthermore, adding 100 µM glibenclamide at positive potentials and 400 µM tolbutamide at negative or positive voltages caused a strong inhibition of channel activity. Finally Western blot analyses provided evidence for Kir6.2, SUR1 and/or SUR2B, and SUR2A expression in our RER fractions. It was concluded on the basis of these observations that the channel previously characterized in RER membranes corresponds to KATP, suggesting that opening of this channel may enhance Ca2+ releases, alter the dynamics of the Ca2+ transient and prevent accumulation of Ca2+ in the ER during Ca2+ overload. 相似文献
14.
Parnian Javad Hoseindokht Maryam Khademi Zahra Moosavi Maedeh Soheili Zahra Soheila Samie Shahram Zomorodipour Alireza 《Biotechnology letters》2022,44(5):713-728
Biotechnology Letters - To improve the expression efficiency of recombinant hFIX, by enhancing its γ-carboxylation, which is inhibited by Calumenin (CALU), we used intronic artificial... 相似文献
15.
Alireza Karimi Maedeh Haghighatnama Afsaneh Motevalli Haghi 《Computer methods in biomechanics and biomedical engineering》2013,16(16):1768-1774
The skin, being a multi-layered material, is responsible for protecting the human body from the mechanical, bacterial, and viral insults. The skin tissue may display different mechanical properties according to the anatomical locations of a body. However, these mechanical properties in different anatomical regions and at different loading directions (axial and circumferential) of the mice body to date have not been determined. In this study, the axial and circumferential loads were imposed on the mice skin samples. The elastic modulus and maximum stress of the skin tissues were measured before the failure occurred. The nonlinear mechanical behavior of the skin tissues was also computationally investigated through a suitable constitutive equation. Hyperelastic material model was calibrated using the experimental data. Regardless of the anatomic locations of the mice body, the results revealed significantly different mechanical properties in the axial and circumferential directions and, consequently, the mice skin tissue behaves like a pure anisotropic material. The highest elastic modulus was observed in the back skin under the circumferential direction (6.67 MPa), while the lowest one was seen in the abdomen skin under circumferential loading (0.80 MPa). The Ogden material model was narrowly captured the nonlinear mechanical response of the skin at different loading directions. The results help to understand the isotropic/anisotropic mechanical behavior of the skin tissue at different anatomical locations. They also have implications for a diversity of disciplines, i.e., dermatology, cosmetics industry, clinical decision making, and clinical intervention. 相似文献
16.
Ghaffari Maedeh Kalantar Seyed Mehdi Hemati Mahdie Dehghani Firoozabadi Ali Asri Amir Shams Ali Jafari Ghalekohneh Sina Haghiralsadat Fateme 《Biotechnology letters》2021,43(5):981-994
Biotechnology Letters - Tumor suppressor miRNAs, miR-15a and miR-16–1, with high-specificity and oncogenic targeting of Bcl-2, can target tumor tissues. Disadvantages of the clinical... 相似文献
17.
Alipour Kafi Sahar Karimi Ebrahim Akhlaghi Motlagh Mahmood Amini Zahra Mohammadi Ali Sadeghi Akram 《Plant and Soil》2021,462(1-2):125-140
Plant and Soil - The aims of this work were (i) to find a soil indicator to predict durum wheat yield response to Zn fertilization, (ii) to compare the effect of various Zn fertilization strategies... 相似文献
18.
Yipeng Sun Maedeh Amirmaleki Yang Zhao Changtai Zhao Jianneng Liang Changhong Wang Keegan R. Adair Junjie Li Teng Cui Guorui Wang Ruying Li Tobin Filleter Mei Cai Tsun‐Kong Sham Xueliang Sun 《Liver Transplantation》2020,10(28)
Lithium metal is regarded as the “Holy Grail” of anode materials due to its low electrochemical potential and high theoretical capacity. Unfortunately, its unstable solid electrolyte interphase (SEI) leads to low Coulombic efficiency (CE) and serious safety issues. Herein, a hybrid nanoscale polymeric protective film with tunable composition and improved stiffness is developed by incorporating aluminum crosslinkers into the polymer chains. The Li plating/stripping process is regulated through the protective coating and the dendrite growth is effectively suppressed. Promisingly, the protected Li can deliver stable performance for more than 350 h with a cycling capacity of 2 mAh cm?2 without a notable increase in overpotential. Moreover, a stable charge/discharge cycling in Li–O2 batteries with the protected Li can be maintained for more than 600 h. This work provides guidance on the rational design of electrode interfaces and opens up new opportunities for the fabrication of next‐generation energy storage systems. 相似文献
19.
Mohammad Javad Mousavi Ahmadreza Jamshidi Arvind Chopra Saeed Aslani Massoomeh Akhlaghi Mahdi Mahmoudi 《Journal of cellular physiology》2019,234(1):335-347
Epigenetics refers to a set of regulatory mechanisms that affect gene expression, while the original sequence of the DNA remains unchanged. Because the advance of noncoding RNAs (ncRNAs), the role of microRNAs (miRNAs) has been gradually highlighted in the regulation of numerous cellular processes. A bulk of studies has identified that ncRNAs might be divided into several subtypes. On the one hand, investigations have disclosed the role of these molecules in normal physiological conditions of the cells. On the other hand, there is sufficient evidence that ncRNAs participate in the pathogenesis of diseases. Through this review article, we attempted to gain a comprehensive understanding of the role of ncRNAs, long ncRNAs, miRNAs, and other subtypes in pathogenesis, diagnosis, and treatment of rheumatoid arthritis (RA). Research demonstrated aberrant expression of several miRNAs in various cell and tissue types of patients with RA in comparison to the healthy individuals as well as in animal studies. Furthermore, plausible molecular mechanisms of alterations in ncRNAs expression has been discussed in causing the disease state. These alterations seem promising to be used as biomarkers in RA diagnosis. Alternately, they might be targeted by drugs to interrupt inflammation and other disease complications to treat patients with RA. 相似文献
20.
Elham Sadat Aghaei Meibodi Maedeh Darziani Azizi Malieh Paknejad Bagher Larijani Kobra Omidfar 《Molecular biology reports》2012,39(12):10851-10858
In the present study, a sensitive and competitive chemiluminescence immunoassay (CLIA) was developed in order to detect human serum albumin (HSA) in urine specimen. The method utilizes a home-made monoclonal anti-albumin antibody conjugated to horseradish peroxidase enzyme (mAb-HRP). Sensitivity, specificity and linearity of the assay were evaluated. According to the results, the proper concentration of HSA and mAb-HRP conjugates was 800?ng/100?μl and 1:200 respectively. In optimal conditions, this method could detect HSA in a high linear range of 10–200?μg?ml?1 with the low detection limit of 0.025?μg?ml?1. No evidence of interference with presence of probable substances in the urine samples indicated its high specificity and selectivity. Moreover, high reproducibility as well as high sensitivity and specificity of the test were confirmed using diabetic and non-diabetic samples. Significant concordance was observed between CLIA and immunoturbidimetry assay regarding detection of HSA. The results of the present study can be considered in accordance with the current demands such as reliability, accuracy, convenience and high speed of performance for a precise protein detection method. Furthermore, it may be regarded as a more rapid, simpler and cheaper alternative compared to other sophisticated assays. 相似文献