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901.
DNA gyrase, an essential enzyme that regulates DNA topology in bacteria, is the target of fluoroquinolones. Three fluoroquinolone-resistant
mutants derived from one strain of Clostridium perfringens had amino acid substitutions of glycine 81 to cysteine, aspartic acid 87 to tyrosine, or both, in α-helix-4 of gyrase A.
The gyrase mutations affected the growth kinetics of mutants differently when the mutants were exposed to increasing concentrations
of gatifloxacin and ciprofloxacin. Fluoroquinolone concentration-dependent effects observed during growth in the exponential
and stationary phases depended on the presence of particular gyrA mutations. Introduction of a wild-type gyrA gene into the mutants enhanced their susceptibility to fluoroquinolones and decreased their growth rates proportional to
increases in fluoroquinolone concentrations. Amino acid substitutions in α-helix-4 of gyrase A protected C. perfringens from fluoroquinolones, and a strain with two substitutions was the most resistant. 相似文献
902.
Roghayeh Pourbagher Hossein Ghorbani Haleh Akhavan-Niaki Seyed Gholam Ali Jorsaraei Sadegh Fattahi Sahar Ghooran Zeinab Abedian Masoumeh Ghasemi Fatemeh Saeedi Negar Jafari Behnam Kalali Amrollah Mostafazadeh 《Reports of Biochemistry & Molecular Biology》2021,10(1):105
Background:Stem cell differentiation therapy is a promising strategy in cancer treatment. we show that protein cocktail prepared from serum starved fibroblasts has therapeutic potential based on this strategy. Methods:The condition medium was prepared from foreskin isolated fibroblasts and analyzed by Liquid chromatography electrospray ionization mass spectrometry-mass spectrometry (LC-ESI-MS/MS). LA7 mammary gland cancer stem cells originated tumors were induced in Sprague Dawley rats. The rats treated subcutaneously with DMEM (group A), condition medium (group B), or normal saline (group C) once daily for 7 days. Then the tumors were removed and divided into the two parts, one part was used to quantify gene expression by stem-loop RT-qPCR assay and the other part was used for Hematoxylin & Eosin (H & E), Giemsa, and immunohistochemistry (IHC) staining.Results:All induced tumors appeared as sarcomatoid carcinoma (SC). Immunohistochemistry staining confirmed this conclusion by recognizing the tumor as Ki67+, cytokeratin+, vimentine+, and estrogen receptor negative SC. RT-qPCR analysis revealed that Oct4-, Sox-2, Nanog- gene expression was much reduced in the condition medium treated tumors versus proper controls (p< 0.05). Tissue necrosis was more prevalent in this group while tumors volume was diminished almost by 40%. The LC-ESI-MS/MS analysis unrevealed the stemness reducing and the cell death inducing proteins such as, pigment epithelium-derived factor (PEDF), insulin like growth factor binding protein-5 (IGFBP-5) and -7 (IGFBP-7) in the condition medium.Conclusion:This study showed that the substances released from starved human fibroblasts were able to down-regulate the stemness-related genes and induce necrosis in LA7 derived tumors.Key Words: Breast cancer, Cancer Stem cells, Cell differentiation, Fibroblasts, Gene expression 相似文献
903.
Forqani Mehrnaz Hosseini Seyed Masoud Farahmand Behrokh Saleh Maryam Shokouhi Hadiseh Torabi Ali Fotouhi Fatemeh 《Biotechnology letters》2021,43(11):2137-2147
Biotechnology Letters - Influenza is one of the most important agents of pandemic outbreak causing substantial morbidity and mortality. Vaccination strategies of influenza must be adapted annually... 相似文献
904.
Darzi Sina Mirzaei Seyed Abbas Elahian Fatemeh Peymani Amir Rahmani Babak Pishkhan Dibazar Shaghayegh Shirian Sadegh Shakeri Chaleshtori Leila Aali Ehsan 《Molecular biology reports》2021,48(11):7105-7111
Molecular Biology Reports - Flavonoids have been demonstrated to have the ability of sensitizing cancer cells to chemotherapy and inverse multidrug resistance via various mechanisms, such as... 相似文献
905.
Hajian Samin Mazdeh Mehrdokht Nouri Fatemeh Roshanaei Ghodratollah Soleimani Meysam 《Molecular biology reports》2021,48(8):6007-6013
Molecular Biology Reports - Multiple sclerosis (MS) is an autoimmune disease described by inflammatory neuronal losses and resultant failures. The disease could abate by interferon-beta... 相似文献
906.
Ravanrouy Fatemeh Niazi Ali Moghadam Ali Taghavi Seyed Mohsen 《Molecular biology reports》2021,48(10):6719-6728
Molecular Biology Reports - DNA methylation is one of the most important epigenetic event that regulates gene expression. In addition to DNA methylation, transgene copy number may induce gene... 相似文献
907.
Utilizing a nano‐sorbent for the selective solid‐phase extraction of vanillic acid prior to its determination by photoluminescence spectroscopy 下载免费PDF全文
Hossein Abdolmohammad‐Zadeh Fatemeh Mahmoudi‐kordi Manoochehr Rahmati 《Luminescence》2014,29(8):1162-1168
Vanillic acid (VA) is a phenolic acid, and acts as a natural antioxidant in fruits, vegetables and plants. The extraction and determination of trace levels of VA in plants is important, because stimulation of protein synthesis and activation of antioxidant enzymes occur in the presence of phenolic acids at trace levels. In this research, a photoluminescence spectroscopic method was developed for the quantification of VA in plant samples after separation and pre‐concentration. Selective extraction of VA from aqueous solution was performed using a solid‐phase extraction column packed with nickel–aluminum layered double hydroxide as a nano‐sorbent. After elution of extracted analyte from the column using 3 mL of a 3 mol/L NaOH solution, its concentration was determined spectrofluorometrically at λem = 357 nm with excitation at λex = 280 nm. The spectrofluorometry method gave a linear response for VA within the range 20.0–900.0 µg/L, with a correlation coefficient of 0.9982. The limit of detection and sorption capacity were 7.6 µg/L and 66.2 mg/g, respectively. The method was validated by comparing the obtained results with gas chromatographic data. This method was used to determine VA in Chenopodium album and Prangos asperula plants. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
908.
Terence N. Bukong Fatemeh Momen-Heravi Karen Kodys Shashi Bala Gyongyi Szabo 《PLoS pathogens》2014,10(10)
Antibodies targeting receptor-mediated entry of HCV into hepatocytes confer limited therapeutic benefits. Evidence suggests that exosomes can transfer genetic materials between cells; however, their role in HCV infection remains obscure. Here, we show that exosomes isolated from sera of chronic HCV infected patients or supernatants of J6/JFH1-HCV-infected Huh7.5 cells contained HCV RNA. These exosomes could mediate viral receptor-independent transmission of HCV to hepatocytes. Negative sense HCV RNA, indicative of replication competent viral RNA, was present in exosomes of all HCV infected treatment non-responders and some treatment-naïve individuals. Remarkably, HCV RNA was associated with Ago2, HSP90 and miR-122 in exosomes isolated from HCV-infected individuals or HCV-infected Huh7.5 cell supernatants. Exosome-loading with a miR-122 inhibitor, or inhibition of HSP90, vacuolar H+-ATPases, and proton pumps, significantly suppressed exosome-mediated HCV transmission to naïve cells. Our findings provide mechanistic evidence for HCV transmission by blood-derived exosomes and highlight potential therapeutic strategies. 相似文献
909.
Fatemeh Pakpour Ghasem Najafpour Meisam Tabatabaei Masoud Tohidfar Habiboallah Younesi 《Bioprocess and biosystems engineering》2014,37(5):923-930
Biohydrogen production through water–gas shift (WGS) reaction by a biocatalyst was conducted in batch fermentation. The isolated photosynthetic bacterium Rhodopseudomonas palustris PT was able to utilize carbon monoxide and simultaneously produce hydrogen. Light exposure was provided as an indispensable requirement for the first stage of bacterial growth, but throughout the hydrogen production stage, the energy requirement was met through the WGS reaction. At ambient pressure and temperature, the effect of various sodium acetate concentrations in presence of CO-rich syngas on cell growth, carbon monoxide consumption, and biohydrogen production was also investigated. Maximal efficiency of hydrogen production in response to carbon monoxide consumption was recorded at 86 % and the highest concentration of hydrogen at 33.5 mmol/l was achieved with sodium acetate concentration of 1.5 g/l. The obtained results proved that the local isolate; R. palustris PT, was able to utilize CO-rich syngas and generate biohydrogen via WGS reaction. 相似文献
910.
Pantea Izadi Mehrdad Noruzinia Forouzandeh Fereidooni Zahra Mostakhdemine Hosseini Fatemeh Kamali 《Molecular biology reports》2014,41(11):7607-7612
Reproductive backgrounds, such as age at menarche and menopause, age of first full-term pregnancy (FFTP), number of full-term deliveries and oral contraceptive use are main hormone-related risk factors of breast cancer. It seems that the mentioned factors may affect the risk of breast cancer by enhancing the duration of exposure to estrogen as a potent carcinogen for breast tissue, but the molecular mechanism which links each risk factor to breast cancer is unclear. Estrogen mainly works via its nuclear receptor (ERα). As epigenetic alterations such as CpG methylation are potential links between endogenous or exogenous exposures and genome, we hypothesized that hormone-related risk factors may correlate with the epigenetic marks of the ERα promoter in breast tumors. In the present study, the CpG methylation status of the ERα gene in 99 samples of breast tumors belonged to women with different reproductive histories was evaluated. The reproductive history data were collected from patients. ERα CpG methylation was investigated by methylation specific PCR in DNA samples were obtained from the breast tumors. We could show that some of the hormone-related risk factors (early FFTP and increased number of pregnancies) were inversely correlated with epigenetic marks in ERα gene in breast tumors. Other hormone-related risk factors such as age of menarche and menopause and oral contraceptive use did not show any association with ERα methylation. It seems that pregnancy-related risk factors in comparison with other hormone-related factors work via different mechanism. As ERα methylation is a poor prognosis marker in breast tumors, its association with some modifiable reproductive risk factors (FFTP age and numbers of pregnancies) reiterates the importance of programming reproductive life style not only for prevention of breast cancer but also in favoring the prognosis of the affected women. The exact molecular mechanisms of the observed correlation need more investigation in the future. 相似文献