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71.
Mohammad Babar Ali Yaser Hassan Dewir Eun-Joo Hahn Kee-Yoeup Paek 《Environmental and Experimental Botany》2008,63(1-3):297-304
The aim of this study was to investigate the effect of CO2 at various concentrations (1, 2.5 and 5%) on antioxidant enzymes and ginsenoside accumulation in Panax ginseng roots in 5 l airlift bioreactors (working volume 4 l). One and 2.5% CO2 was beneficial for root biomass accumulation, but 5% CO2 decreased the biomass. Ginsenoside concentration decreased with increasing concentration of CO2. No significant difference was observed in the malondialdehyde (MDA) content and lipoxygenase (LOX) activity between respective controls and CO2 treated roots. Antioxidant enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), glutathione reductase (GR), catalase (CAT), guaiacol peroxidase (G-POD) including reduced ascorbate and total glutathione were induced in CO2 exposed roots which emphasized the protective role of antioxidants against CO2 induced stress. Superoxide dismutase activity (SOD) which was induced after 15 days was significantly inhibited after 45 days. Glutathione-S-transferase (GST) and glutathione peroxidase (GPX) activities also increased when the roots were subjected to 1 and 2.5% CO2 compared to the respective controls but not at 5%. A higher reduced ascorbate to oxidized (ASC/DHA) ratio in CO2 treated root indicates the plant's ability to tolerate CO2 stress. These observations suggest that an increase in antioxidant enzymes may affect a defense response to the cellular damage induced by CO2. Probably, this increase could not stop the deleterious effects of CO2 concentration on ginsenoside concentration, but reduced stress severity and thereby allowing root growth to occur. 相似文献
72.
Steroid sulfatase (STS) catalyzes the desulfation of biologically inactive sulfated steroids to yield biologically active desulfated steroids and is currently being examined as a target for therapeutic intervention for the treatment of breast cancer. We previously demonstrated that 4-formyl estrone is a time- and concentration-dependent inhibitor of STS. We have prepared a series of 4-formylated estrogens and examined them as irreversible STS inhibitors. Introducing a formyl, bromo or nitro group at the 2-position of 4-formylestrone resulted in loss of concentration and time-dependent inhibition and a considerable decrease in binding affinity. An estradiol derivative bearing a formyl group at the 4-position and a benzyl group at the 17β-position yielded a potent concentration and time-dependent STS inhibitor with a K(I) of 85 nM and a k(inact) of 0.021 min(-1) (k(inact)/K(I) of 2.3 × 10(5)M(-1)min(-1)). Studies with estrone or estradiol substituted at the 4-position with groups other than a formyl group revealed that good reversible inhibitors can be obtained by introducing small electron withdrawing groups at this position. An estradiol derivative with fluorine at the 4-position and a benzyl group at the 17β-position yielded a potent, reversible inhibitor of STS with an IC(50) of 40 nM. The introduction of relatively small electron withdrawing groups at the 4-position of estrogens and their derivatives may prove to be a general approach to enhancing the potency of estrogen-derived STS inhibitors. 相似文献
73.
Marzieh Ghasemi Mahnaz Azarnia Mansoor Jamali Ghadireh Mirabolghasemi Shahram Nazarian Mohammad Mehdi Naghizadeh Majid Rajabi Yaser Tahamtani 《Tissue & cell》2014
Inflammation and oxidation are two important factors in the pathogenesis of liver. Ephedra pachyclada (EP) is a traditional medical herb that has anti-inflammatory and anti-oxidant activities. During this study, anti-oxidant activities of the EP extract was measured in vitro by 2,2′- diphenyl-1-picrylhydrazyl (DPPH) and β-Carotene bleaching assays. Then, we examined possible in vivo hepatoprotective effects of EP extract on mouse models of carbon tetrachloride (CCl4)-induced chronic and acute liver failure. To produce mouse models of chronic and acute liver injuries, male SW1 mice were interaperitoneally injected with 1 ml/kg body weight (bw) CCl4 biweekly for 42 days and a single dose of 2 ml/kg bw, respectively. In the experimental groups, mouse models were treated with low (140 mg/kg bw) and high (1400 mg/kg bw) doses of the EP extract. Olive oil and water treated mice were considered as controls during model derivation and EP extract treatment respectively. The results showed the antioxidant activity of EP extract and a significant reduction of all parameters of CCl4-induced liver injury such as relative liver weight, necrosis, fibrosis, inflammation, and serum aspartate transaminase (AST) and alanine aminotransferase (ALT) in mouse models of acute and chronic liver injury treated with EP extract. Therefore, EP induces its hepatoprotective effects probably by suppressing oxidative stress and inhibit inflammation in the liver and is able to protect the liver against CCl4-induced acute and chronic injuries. 相似文献
74.
Karsten Arends Ertugrul-Kaan Celik Ines Probst Nikolaus Goessweiner-Mohr Christian Fercher Lukas Grumet Cem Soellue Mohammad Yaser Abajy Tuerkan Sakinc Melanie Broszat Katarzyna Schiwon Guenther Koraimann Walter Keller Elisabeth Grohmann 《Journal of bacteriology》2013,195(19):4436-4444
pIP501 is a conjugative broad-host-range plasmid frequently present in nosocomial Enterococcus faecalis and Enterococcus faecium isolates. We focus here on the functional analysis of the type IV secretion gene traG, which was found to be essential for pIP501 conjugative transfer between Gram-positive bacteria. The TraG protein, which localizes to the cell envelope of E. faecalis harboring pIP501, was expressed and purified without its N-terminal transmembrane helix (TraGΔTMH) and shown to possess peptidoglycan-degrading activity. TraGΔTMH was inhibited by specific lytic transglycosylase inhibitors hexa-N-acetylchitohexaose and bulgecin A. Analysis of the TraG sequence suggested the presence of two domains which both could contribute to the observed cell wall-degrading activity: an N-terminal soluble lytic transglycosylase domain (SLT) and a C-terminal cysteine-, histidine-dependent amidohydrolases/peptidases (CHAP) domain. The protein domains were expressed separately, and both degraded peptidoglycan. A change of the conserved glutamate residue in the putative catalytic center of the SLT domain (E87) to glycine resulted in almost complete inactivity, which is consistent with this part of TraG being a predicted lytic transglycosylase. Based on our findings, we propose that TraG locally opens the peptidoglycan to facilitate insertion of the Gram-positive bacterial type IV secretion machinery into the cell envelope. 相似文献
75.
Sharifi Masoomeh Nazarinia Donya Ramezani Fatemeh Azizi Yaser Naderi Nasim Aboutaleb Nahid 《Molecular biology reports》2021,48(3):2507-2518
Molecular Biology Reports - Nesfatin-1 as a new energy-regulating peptide has been known to display a pivotal role in modulation of cardiovascular functions and protection against... 相似文献
76.
Srinivasan Raj Samuel Mebin George Mathew Sushanthi G Suresh Sudhir Rama Varma Emad S. Elsubeihi Fazil Arshad Yaser Elkareimi Nesrine A. Elsahn Ebtesam Khalil 《Saudi Journal of Biological Sciences》2021,28(4):2591-2597
Pediatric dental emergency management were temporarily suspended during the COVID-19 pandemic, which worsened urgent dental needs. This retrospective study investigated the management of pediatric emergencies during COVID-19 lockdown and the trends in parental preferences from March to July in 2019 and 2020. Pediatric dental emergencies managed during pandemic was collated, procedures were categorized (emergency, restorative, preventive, elective) and trends in parental treatment preference was compared from March-July 2019/2020. Bivariate analysis was performed using fisher-exact test and statistical significance was set at 5%. Total 1081 children were treated during COVID-19 lockdown, and 1509 procedures were performed, of which 20.8% were emergency, 42% restorative, 24.4% preventive, 12.6% elective. In 2019, 7462 children were treated; and except for emergency (10.6%), other procedures were comparable to 2020. Extractions (267) predominated in 2020 followed by sealants (195); but in 2019, pulectomy (1268), scaling (1251) were predominant. None of the residents who performed aerosol procedures got infected with COVID-19 during the lockdown. Emergency dental needs among pediatric patients were very high during the COVID-19 pandemic in South India, and there was not much change in the trend in parental treatment preference in 2019 and 2020. Further, aerosol procedures did not increase the risk of COVID-19 during the pandemic provided proper universal precautions were followed. 相似文献
77.
Archana A. Gupta Supriya Kheur Ravindra V. Badhe A. Thirumal Raj Ramesh Bhonde Amit Jaisinghani Nishant Vyas Vikrant R. Patil Yaser Ali Alhazmi Sameena Parveen Hosam Ali Baeshen Shankargouda Patil 《Saudi Journal of Biological Sciences》2021,28(4):2210-2215
Vitamin D is a commonly used bone modulator in regenerative medicine. Several modalities have been explored for the delivery of vitamin D including nanoparticles and scaffold. The present study aimed to assess the potential use of a bio-degradable chitosan scaffold for the delivery of vitamin D. The objectives included fabrication of a bio-degradable chitosan scaffold, integration of vitamin D into the scaffold, characterization of the vitamin D integrated scaffold. Characterization was carried out using, X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The structure of the scaffold was assessed by scanning electron microscopy. The scaffold was placed in phosphate buffer saline and the release duration of vitamin D was observed using UV spectrophotometry. Dental pulp mesenchymal stem cells were added to the scaffold to study the scaffold associated toxicity and the functionality of the scaffold released vitamin D. The vitamin D release period from the scaffold was estimated to be for 80 hrs. MTT assay of the stem cells was comparable to that of the control group (stem cells cultured in media) inferring that the scaffold is not toxic towards the stem cells. The positive alizarin red S staining, a higher expression of alkaline phosphatase, osteocalcin, and RunX2 confirmed the functional capability (osteogenic differentiation of the stem cells) of the released vitamin D. Based on the data from the present study, it can be inferred that chitosan scaffold can be used for the sustained delivery of functional vitamin D for 3–5 days. 相似文献
78.
SwS: a solvation web service for nucleic acids 总被引:2,自引:0,他引:2
SwS, based on a statistical analysis of crystallographic structures deposited in the NDB, is designed to provide an exhaustive overview of the solvation of nucleic acid structural elements through the generation of 3D solvent density maps. A first version (v1.0) of this web service focuses on the interaction of DNA, RNA and hybrid base pairs linked by two or three hydrogen bonds with water, cations and/or anions. Data provided by SwS are updated on a weekly basis and can be used by: (i) those involved in molecular dynamics simulation studies for validation purposes; (ii) crystallographers for help in the interpretation of solvent density maps; and all those involved in (iii) drug design and, more generally, in (iv) nucleic acid structural studies. SwS provides also statistical data related to the frequency of occurrence of different types of base pairs in crystallographic structures and the conformation of the involved nucleotides. This web service has been designed to allow a maximum of flexibility in terms of queries and has also been developed with didactic considerations in mind. AVAILABILITY: http://www-ibmc.u-strasbg.fr/arn/sws.html 相似文献
79.
Rakhshan Kamran Azizi Yaser Naderi Nasim Ghardashi Afousi Alireza Aboutaleb Nahid 《International journal of peptide research and therapeutics》2019,25(2):613-621
International Journal of Peptide Research and Therapeutics - Emerging evidence has shown that ELA peptide plays a pivotal role in cardiac development and modulation of vascular and cardiac... 相似文献
80.
Macromixing hydrodynamic study in draft-tube airlift reactors using electrical resistance tomography
Farouza Gumery Farhad Ein-Mozaffari Yaser Dahman 《Bioprocess and biosystems engineering》2011,34(2):135-144
The present study summarizes results of mixing characteristics in a draft tube airlift bioreactor using ERT. This technique
offers the possibility for noninvasive and nonintrusive visualization of flow fields in the bioreactor and has rarely been
utilized previously to analyze operating parameters and mixing characteristics in this type of bioreactors. Several operating
parameters and geometric characteristics were examined. In general, results showed that the increase in superficial gas velocity
corresponds to an increase in energy applied and thus, to a decrease in mixing time. This generally corresponded to an increase
in liquid circulation velocity and shear rate values. Bottom clearances and draft tube diameters affected flow resistance
and frictional losses. The influence of sparger configurations on mixing time and liquid circulation velocity was significant
due to their effect on gas distribution. However, the effect of sparger configuration on shear rate was not significant, with
20% reduction in shear rates using the cross-shaped sparger. Fluid viscosity showed a marked influence on both mixing times
and circulation velocity especially in the coalescing media of sugar and xanthan gum (XG) solutions. Results from this work will help to develop a clear pattern for operation and mixing that can help to improve
several industrial processes, especially the ones related to emerging fields of technology such as the biotechnology industry. 相似文献