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131.
132.
Induction of Bacillus subtilis expression system using environmental stresses and glucose starvation
Reza Panahi Ebrahim Vasheghani-Farahani Seyed Abbas Shojaosadati Bijan Bambai 《Annals of microbiology》2014,64(2):879-882
The application of safe and cheap inducers is important in the field of fermentation technology, which persuades employing new expression systems. In this study, a Bacillus subtilis expression system was induced by applying starvation and environmental stresses to produce xylanase. The expression plasmid harbors SigB-dependent ohrB promoter. The target gene was expressed by inoculating the recombinant strain into glucose-limited synthetic medium resulting in a sharp increase of xylanase activity at the end of logarithmic growth phase. The recombinant strain was able to express the xylanase enzyme 14-fold higher than that of the control one. The induction was also performed by exposing the recombinant strain to NaCl and ethanol stresses, and heat shock; the strain growing in LB showed 5-, 15- and 6-fold increases in xylanase activity, respectively. The best induction using environmental stresses was achieved by applying the salt stress in the synthetic medium. The maximum expression for NaCl and ethanol stresses occurred after 40 min of induction. All observed inductions were related to activation of SigB protein causing expression of the SigB-dependent xylanase gene. This SigB-dependent expression system can be considered as a biotechnology tool and an alternative to eliminate the cost of conventional inducers. 相似文献
133.
Cari van Schalkwyk Ebrahim Variava Adrienne E. Shapiro Modiehi Rakgokong Katlego Masonoke Limakatso Lebina Alex Welte Neil Martinson 《PloS one》2014,9(4)
Objective
To report the incidence rates of TB and HIV in household contacts of index patients diagnosed with TB.Design
A prospective cohort study in the Matlosana sub-district of North West Province, South Africa.Methods
Contacts of index TB patients received TB and HIV testing after counseling at their first household visit and were then followed up a year later, in 2010. TB or HIV diagnoses that occurred during the period were determined.Results
For 2,377 household contacts, the overall observed TB incidence rate was 1.3 per 100 person years (95% CI 0.9–1.9/100py) and TB incidence for individuals who were HIV-infected and HIV seronegative at baseline was 5.4/100py (95% CI 2.9–9.0/100py) and 0.7/100py (95% CI 0.3–1.4/100py), respectively. The overall HIV incidence rate was 2.2/100py (95% CI 1.3–8.4/100py).Conclusions
In the year following a household case finding visit when household contacts were tested for TB and HIV, the incidence rate of both active TB and HIV infection was found to be extremely high. Clearly, implementing proven strategies to prevent HIV acquisition and preventing TB transmission and progression to disease remains a priority in settings such as South Africa. 相似文献134.
Shukkur M. Farooq Nithin B. Boppana Devarajan Asokan Shamala D. Sekaran Esaki M. Shankar Chunying Li Kaliappan Gopal Sazaly A. Bakar Harve S. Karthik Abdul S. Ebrahim 《PloS one》2014,9(4)
Oxalate toxicity is mediated through generation of reactive oxygen species (ROS) via a process that is partly dependent on mitochondrial dysfunction. Here, we investigated whether C-phycocyanin (CP) could protect against oxidative stress-mediated intracellular damage triggered by oxalate in MDCK cells. DCFDA, a fluorescence-based probe and hexanoyl-lysine adduct (HEL), an oxidative stress marker were used to investigate the effect of CP on oxalate-induced ROS production and membrane lipid peroxidation (LPO). The role of CP against oxalate-induced oxidative stress was studied by the evaluation of mitochondrial membrane potential by JC1 fluorescein staining, quantification of ATP synthesis and stress-induced MAP kinases (JNK/SAPK and ERK1/2). Our results revealed that oxalate-induced cells show markedly increased ROS levels and HEL protein expression that were significantly decreased following pre-treatment with CP. Further, JC1 staining showed that CP pre-treatment conferred significant protection from mitochondrial membrane permeability and increased ATP production in CP-treated cells than oxalate-alone-treated cells. In addition, CP treated cells significantly decreased the expression of phosphorylated JNK/SAPK and ERK1/2 as compared to oxalate-alone-treated cells. We concluded that CP could be used as a potential free radical-scavenging therapeutic strategy against oxidative stress-associated diseases including urolithiasis. 相似文献
135.
PIA and rSesC Mixture Arisen Antibodies Could Inhibit the Biofilm-Formation in Staphylococcus aureus
Bahman Mirzaei Ryhane Babaei Mohammad Reza Haghshenas Fatemeh Mohammadi Pegah Homayoni Ebrahim Shafaei 《Reports of Biochemistry & Molecular Biology》2021,10(1):1
Background:Staphylococcus aureus as a causative agent of hospital-acquired infections has been considered as the primary concern in biomaterial-related infections (BAIs).Methods:Following the purification of polysaccharide intercellular adhesion (PIA) as an efficient macromolecule in biofilm formation in the native condition, recombinant S. epidermidis surface-exposed rSesC protein, with the most homology to clumping factor A (ClfA) in S. aureus was cloned and expressed in a prokaryotic host as well. Fourier transform infrared spectrometry (FTIR) and Western blotting procedure analyzed purified PIA and protein, respectively. Then, the immune response was evaluated by measuring total IgG titers. Moreover, the capacity of Anti-biofilm forming activity of arisen antibodies to a biofilm-forming S. aureus strains was assessed by the semi-quantitative micro-plate procedure.Results:Data showed that the total IgGs were boosted in mice immunized sera. By performing an inhibition assay, the biofilm inhibitory effect of secreted antibodies to test strain was observed. Arisen antibodies against the mixture significantly were more potent than PIA and rSesC, when comparing individual antigens in a biofilm inhibition assay.Conclusion:immunization of mice with mentioned antigens especially a mixture of them, could eliminate the biofilm formation process in S. aureus. Hopefully, this study corresponds to the suggestion that the immunization of mice with PIA and rSesC candidate vaccines could protect against S. aureus infection.Key Words: PIA, Purification, Staphylococcus aureus, rSesC, Vaccine candidates 相似文献
136.
Barbara J. Jefferis Peter H. Whincup Paul Welsh S. Goya Wannamethee Ann Rumley Shah Ebrahim Debbie A. Lawlor Gordon D.O. Lowe 《Cytokine》2013,61(2):513-520
AimIL-18 is hypothesized to destabilise atherosclerotic plaques, leading to thrombotic events and epidemiologic studies suggest that IL-18 may increase risk of CHD or CVD.We examined prospective associations between levels of serum IL-18 and new CHD and stroke events in older men and women from a general population.MethodsA case-control study was nested within a prospective cohort of men and women aged 60–79 years recruited from general practices in 25 British towns in 1998–2000 and followed-up for 7.5 years for fatal and non-fatal MI and stroke. Baseline IL-18 was measured in stored serum samples of incident cases of MI (n = 364) or stroke (n = 300) and two controls per case.ResultsGeometric mean IL-18 levels were higher among the 364 MI cases than the 706 controls; 417.84 pg/mL (IQR 316.25, 537.44) compared to 386.90 pg/mL (IQR 296.54, 482.33), p(difference) = 0.002. IL-18 was positively associated with adverse lipid and inflammatory profiles. Men and women in the top third of baseline IL-18 levels had an age and sex-adjusted odds ratio (OR) for MI of 1.31 (95%CI 0.92, 1.85) compared with those in the lowest third; this attenuated to 1.05 (95%CI 0.72, 1.53) after additional adjustment for established vascular and inflammatory risk factors. Each doubling of IL-18 level was associated with an increased OR for MI 1.34 (95%CI 1.04, 1.72), which was attenuated on adjustment for established vascular and inflammatory risk factors; 1.09 (95%CI 0.83, 1.44).Geometric mean IL-18 levels did not differ between stroke cases and controls. The OR for stroke associated with the highest compared to the lowest tertile of IL-18 was 1.24 (95%CI 0.84, 1.84). Results for MI and stroke did not differ by presence of pre-existing CVD, gender or age.ConclusionsCirculating IL-18 levels were strongly associated with a range of established and novel risk factors but were not independently associated with risk of MI or stroke in our study. 相似文献
137.
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
138.
Birnie K Cooper R Martin RM Kuh D Sayer AA Alvarado BE Bayer A Christensen K Cho SI Cooper C Corley J Craig L Deary IJ Demakakos P Ebrahim S Gallacher J Gow AJ Gunnell D Haas S Hemmingsson T Inskip H Jang SN Noronha K Osler M Palloni A Rasmussen F Santos-Eggimann B Spagnoli J Starr J Steptoe A Syddall H Tynelius P Weir D Whalley LJ Zunzunegui MV Ben-Shlomo Y Hardy R;HALCyon study team 《PloS one》2011,6(1):e15564
Background
Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.Methods and Findings
Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.Conclusions
Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life. 相似文献139.
Deni Pranowo Nuryono Ali Agus Sri Wedhastri Elisabeth Viktoria Reiter Ebrahim Razzazi-Fazeli Jürgen Zentek 《Mycotoxin Research》2013,29(3):135-139
Samples from large (100–200 tons) batches of palm kernel cake (PKC, n?=?20) and copra meal (CM, n?=?13) were collected at production facilities of four Indonesian feed mill manufacturers and analysed for aflatoxin B1 (AFB1) by ELISA. Recoveries using spiked samples ranged from 86 to 113 %, with relative standard deviations of <9 % (PKC) and <6 % (CM). All batches were positive for AFB1: in PKC, at levels of 5.8–93.1 μg/kg (mean 49 μg/kg), and in CM, at levels of 1.1–147 μg/kg (mean 38.1 μg/kg). AFB1 levels were, in most batches, below the maximum level (100 μg/kg) recommended by the National Standardisation Agency, Republic of Indonesia. However, about half of the batches exceeded both the European Union and USA regulations for AFB1 in animal feed. In conclusion, serious efforts are necessary to control production, storage and shipment of palm kernel cake and copra meal for feed purposes, and clearly not only for products intended for export but also to reduce AFB1 levels in domestic Indonesian feed. 相似文献
140.
Malihe Ebrahimi Hassan Hadadzadeh Badraldin Ebrahim Sayed Tabatabaei Zahra Jannesari Ghazale Khaksar 《Journal of biomolecular structure & dynamics》2013,31(11):2316-2329
The guanine-rich sequence, specifically in DNA, telomeric DNA, is a potential target of anticancer drugs. In this work, a mononuclear Fe(III) complex containing two meloxicam ligands was synthesized as a G-quadruplex stabilizer. The interaction between the Fe(III) complex and G-quadruplex with sequence of 5′-G3(T2AG3)3-3′ (HTG21) was investigated using spectroscopic methods, molecular modeling, and polymerase chain reaction (PCR) assays. The spectroscopic methods of UV–vis, fluorescence, and circular dichroism showed that the metal complex can effectively induce and stabilize G-quadruplex structure in the G-rich 21-mer sequence. Also, the binding constant between the Fe(III) complex and G-quadruplex was measured by these methods and it was found to be 4.53(±0.30)?×?105 M?1). The PCR stop assay indicated that the Fe(III) complex inhibits DNA amplification. The cell viability assay showed that the complex has significant antitumor activities against Hela cells. According to the UV–vis results, the interaction of the Fe(III) complex with duplex DNA is an order of magnitude lower than G-quadruplex. Furthermore, the release of the complex incorporated in bovine serum albumin nanoparticles was also investigated in physiological conditions. The release of the complex followed a bi-phasic release pattern with high and low releasing rates at the first and second phases, respectively. Also, in order to obtain the binding mode of the Fe(III) complex with G-quadruplex, molecular modeling was performed. The molecular docking results showed that the Fe(III) complex was docked to the end-stacked of the G-quadruplex with a π–π interaction, created between the meloxicam ligand and the guanine bases of the G-quadruplex. 相似文献