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The human promyelocytic cell line, HL-60, shows large changes in endogenous poly(ADP-ribose) and in nuclear ADP-ribosyl transferase activity (ADPRT) during its induced myelocytic differentiation. DNA strand-breaks are an essential activator for this enzyme; and transient DNA strand breaks occur during the myelocytic differentiation of HL-60 cells. We have tested the hypothesis that these post-mitotic, terminally differentiating cells are less efficient in DNA repair, and specifically in DNA strand rejoining, than their proliferating precursor cells. We have found that this hypothesis is not tenable. We observe that there is no detectable reduction in the efficiency of DNA excision repair after exposure to either dimethyl sulphate or gamma-irradiation in HL-60 cells induced to differentiate by dimethyl sulphoxide. Moreover, the efficient excision repair of either dimethyl sulphate or gamma-irradiation induced lesions, both in the differentiated and undifferentiated HL-60 cells, is blocked by the inhibition of ADPRT activity. 相似文献
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Summary Dantrolene-Na is a muscular relaxant which binds to sarcoplasmic reticulum (SR) with high affinity and decreases the availability of Ca2+ channels. The binding of fluorescent compounds, dantrolene-Na, nifedipine and chlortetracycline to the ciliary membrane ofParamecium aurelia has been studied. Dantrolene at the concentrations of 1.9 · 10–5, 3.8 · 10–5 and 7.9 · 10–5 M manifested a punctuated binding pattern to the cell membrane. Isolated cilia also bound dantrolene at their basal portion, whereas deciliated cell bodies lost their dotted binding pattern. Chlortetracycline showed a similar but weaker fluorescent staining. Nifedipine treated cells revealed no sign of fluorescent binding to the membrane and was only taken up in food vacuoles.Based on these observations we propose that dantrolene binding regular arrays ofParamecium cell membrane could be identical to granular plaques observed by electron microscope. The possible functioning of these structures as Ca2+ reservoirs is also discussed. 相似文献
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Omid Haghighi Soheila Davaeifar Hossein Shahbani Zahiri Hadi Maleki Kambiz Akbari Noghabi 《International journal of peptide research and therapeutics》2020,26(2):783-793
Glutamate dehydrogenase (GDH), which is present in most bacteria and eukaryotes’ mitochondria, plays an important role in amino acid metabolism. In g 相似文献
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Moradi Hamid Reza Hajali Vahid Khaksar Zabihollah Vafaee Farzaneh Forouzanfar Fatemeh Negah Sajad Sahab 《Molecular biology reports》2021,48(7):5647-5660
Molecular Biology Reports - Among different pathological mechanisms, neuronal loss and neurogenesis impairment in the hippocampus play important roles in cognitive decline in Alzheimer’s... 相似文献
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Saeed Bahrami Moqadam Ahamd Saleh Asheghabadi Farzaneh Norouzi Hamed Jafarzadeh Ali Khosroabadi Afshin Alagheband Ghazal Bangash Negar Morovatdar Jing Xu 《仿生工程学报(英文版)》2021,18(6):1344-1357
Lack of temperature sensation of myoelectric prosthetic hand limits the daily activities of amputees.To this end,a non-invasive temperature sensation method is proposed to train amputees to sense temperature with psychophysical sensory substitution.In this study,22 healthy participants took part besides 5 amputee participants.The duration time of the study was 31 days with five test steps according to the Leitner technique.An adjustable temperature mug and a Peltier were used to change the temperature of the water/phantom digits to induce temperature to participants.Also,to isolate the surround-ings and show colors,a Virtual Reality(VR)glass was employed.The statistical results conducted are based on the response of participants with questionnaire method.Using Chi-square tests,it is concluded that participants answer the experiment significantly correctly using the Leitner technique(P value<0.05).Also,by applying the"Repeated Measures ANOVA",it is noticed that the time of numbness felt by participants had significant(P value<0.001)difference.Participants could remember lowest and highest temperatures significantly better than other temperatures(P value<0.001);furthermore,the well-trained amputee participant practically using the prosthesis with 72.58%could identify object's temperature with only once time experimenting the color temperature. 相似文献
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Farzaneh Farivar Ali Akbar Moosavi-Movahedi Maryam Salami Mousa Bohlooli Amir Niasari-Naslaji 《Cell biochemistry and biophysics》2013,67(2):727-734
Albumin is a multifunctional non-glycosylated, negatively charged plasma protein, with extraordinary ligand-binding and transport properties, antioxidant functions, and enzymatic activities. Physiologically, albumin transports free fatty acids in plasma and contributes in maintaining colloid osmotic pressure. Recent progresses in using albumin as a versatile protein carrier for drug targeting and for improving the pharmacokinetic profile of peptide or protein-based drugs, increased the attempts for improving albumin stability. Studying the thermal stability of camel albumin may provide us not only new clues for designing recombinant albumins, but also molecular insights on camel physiology. This study aims to determine the thermal stability of camel albumin. Fatted camel serum albumin (FCSA) was purified from blood via combination of Cohn’s method and anion-exchange chromatography. Activated charcoal treatment was used to obtain defatted camel serum albumin (CSA). Fluorescence spectroscopy and differential scanning calorimetry (DSC) were used to study thermal denaturation of this protein. The set of fluorescence spectra were deconvoluted using the convex constraint analysis method (CCA). The results from deconvolution of fluorescence spectroscopy and DSC showed three and two components for CSA and FCSA, respectively. The bimodal DSC transition can be attributed to a crevice between domains I and II and formation of two independent thermodynamic domains. The crevice formation can be prevented by fatty acid binding between domains I and II. The calculated values of ?H v/?H cal, approximately 0.4 for CSA and near 1 for FCSA, confirmed the presence of at least one intermediate in thermal unfolding of CSA and the absence of the intermediate for FCSA. The obtained midpoint transition temperature (T m) of FCSA was about 20 °C higher than that of CSA. Such enormous stabilizing effect may be attributed to the fact that fatty acid serves as glue which preserves different domains beside each other and prevents formation of the mentioned intermediate. 相似文献
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Kamran Maleki Majd Seyed Hossein Karparvarfard Asgar Farahnaky Khosrow Jafarpour 《Food biophysics》2013,8(1):1-11
After determination of sorption isotherms of grape seeds using gravimetric method, five models with temperature effect were used to fit water sorption isotherms of grape seeds to investigate temperature effect on sorption isotherms and its thermodynamic characteristics. Halsey model had minimum mean relative percentage error (M e ) and all other models used were good in fitting experimental data (with M e of less than 10 %). Differential parameters such as net isosteric heat, isosteric heat, differential entropy and integral function such as equilibrium heat, net equilibrium heat, integral entropy and surface potential have been calculated. The net isosteric heat, isosteric heat and differential entropy decreased with moisture content. The net equilibrium enthalpy, equilibrium enthalpy and integral entropy decreased with moisture content. The surface potential at four temperatures (35, 45, 55 and 65 °C) was estimated, and low temperature effect was reported. 相似文献
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