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61.
62.
Nickel and cobalt derivatives of Pseudomonas fluorescens (ATCC 13525) azurin were prepared and their steady-state fluorescence and time-resolved fluorescence monitored. Like the copper-containing native protein, the fluorescence decay of both metallo derivatives was best fit to a sum of three exponentials, whereas the apoazurin from which they were prepared obeyed single-exponential decay kinetics. However, comparison of the lifetimes and fractional of each of the components in these derivatives to those in the oxidized and reduced native proteins revealed significant differences. These results suggest that the presence of a metal center in azurin imparts a conformational heterogeneity which is strongly dependent on the nature of the metal center. Further, the results are used to comment on current ideas concerning the geometry of the active site in this redox protein. 相似文献
63.
Anthony Johns K. Rewers-Felkins P. Devesly Gabor M. Rubanyi Lynne H. Parker-Botelho 《Neurochemistry international》1991,18(4):575-580
Specific receptor-induced signal transduction mechanisms for the endothelin-2 isoform (ET-2), a potent vasoconstrictor of vascular smooth muscle, were examined in Swiss 3T3 cells. Half-maximal binding (EC50) and maximal, saturable binding (Bmax) were estimated from Scatchard analyses and were found to be 24.2 ± 3.3 pM and 56500 ± 1700 sites/cells, respectively. A saturating concentration of ET-2 (100 nM) increased intracellular free calcium (measured by Fura-2 fluorescence) from a resting level of 100 nM to a peak level of 600–800 nM. The initial increase in intracellular free calcium was transitory and was followed by a smaller maintained elevation (250 nM). In the absence of extracellular calcium, ET-2 induced a transitory response equal in size to the peak in the presence of extracellular calcium, but the maintained response was absent. ET-2 increased intracellular free calcium in a concentration-dependent manner with an EC50 of 1 nM. In calcium free solution (2 mM EGTA), ET-2 increased the efflux of 45Ca from cells loaded to isotopic equilibrium (3 h) with 45Ca. The intracellular second messenger, IP3, also increased the calcium efflux from saponin permeabilized 3T3 cells loaded with 45Ca (pCa 6) in the presence of MgATP. In the presence of extracellular calcium, ET-2 significantly increased calcium uptake into 3T3 cells by 92 ± 36.6 pmoles/million cells/2 min (n = 8). It is suggested that ET-2 binds to specific, high affinity receptors in 3T3 cells and that this receptor interaction increases the intracellular free calcium by IP3-induced mobilization of calcium from cellular stores and by increasing influx of extracellular calcium. 相似文献
64.
Abdelwahab ElHusseiny M. M. Bovari-Biri Judit Smuk Gabor Fillinger Janos McPhail Donald Krymskaya Vera P. Pongracz Judit E. 《Apoptosis : an international journal on programmed cell death》2021,26(5-6):253-260
Apoptosis - Tuberous sclerosis, angiomyolipoma and lymphangioleiomyomatosis are a group of diseases characterized by mutation in tuberous sclerosis genes (TSC 1-2). TSC mutation leads to continuous... 相似文献
65.
66.
Gabor J. Barton Malcolm B. Hawken Gill Holmes Michael H. Schwartz 《Computer methods in biomechanics and biomedical engineering》2013,16(1):57-63
The ability of the Movement Deviation Profile (MDP) and Gait Deviation Index (GDI) to detect gait changes was compared in a child with cerebral palsy who underwent game training. Conventional gait analysis showed that sagittal plane angles became mirrored about normality after training. Despite considerable gait changes, the GDI showed minimal change, while the MDP detected a difference equal to a shift between 10-9 on the Functional Assessment Questionnaire scale. Responses of the GDI and MDP were examined during a synthetic transition of the patient's curves from before intervention to a state mirrored about normality. The GDI showed a symmetric response on the two opposite sides of normality but the neural network based MDP gave an asymmetric response reflecting faithfully the unequal biomechanical consequences of joint angle changes. In conclusion, the MDP can detect altered gait even if the changes are missed by the GDI. 相似文献
67.
Swee Tin Aw Michael John Todd Nadine Lehnen Grace Elizabeth Aw Konrad Peter Weber Thomas Eggert Gabor Michael Halmagyi 《PloS one》2013,8(12)
Background
Vestibular reflexes, evoked by human electrical (galvanic) vestibular stimulation (EVS), are utilized to assess vestibular function and investigate its pathways. Our study aimed to investigate the electrically-evoked vestibulo-ocular reflex (eVOR) output after bilateral and unilateral vestibular deafferentations to determine the characteristics for interpreting unilateral lesions such as vestibular schwannomas.Methods
EVOR was recorded with dual-search coils as binocular three-dimensional eye movements evoked by bipolar 100 ms-step at EVS intensities of [0.9, 2.5, 5.0, 7.5, 10.0]mA and unipolar 100 ms-step at 5 mA EVS intensity. Five bilateral vestibular deafferented (BVD), 12 unilateral vestibular deafferented (UVD), four unilateral vestibular schwannoma (UVS) patients and 17 healthy subjects were tested with bipolar EVS, and five UVDs with unipolar EVS.Results
After BVD, bipolar EVS elicited no eVOR. After UVD, bipolar EVS of one functioning ear elicited bidirectional, excitatory eVOR to cathodal EVS with 9 ms latency and inhibitory eVOR to anodal EVS, opposite in direction, at half the amplitude with 12 ms latency, exhibiting an excitatory-inhibitory asymmetry. The eVOR patterns from UVS were consistent with responses from UVD confirming the vestibular loss on the lesion side. Unexpectedly, unipolar EVS of the UVD ear, instead of absent response, evoked one-third the bipolar eVOR while unipolar EVS of the functioning ear evoked half the bipolar response.Conclusions
The bidirectional eVOR evoked by bipolar EVS from UVD with an excitatory-inhibitory asymmetry and the 3 ms latency difference between normal and lesion side may be useful for detecting vestibular lesions such as UVS. We suggest that current spread could account for the small eVOR to 5 mA unipolar EVS of the UVD ear. 相似文献68.
Min Xia Daxin Chen Valeria Endresz Ildiko Faludi Andrea Szabo Eva Gonczol Vijay Kakkar Xinjie Lu 《PloS one》2013,8(12)
Objective
To investigate the antigenic effect of a peptide containing two epitopes of Chlamydia pneumoniae (Cpn) on atherosclerotic lesion formation in mice infected with Cpn.Materials and Methods
Six-week-old Apobtm2SgyLdlrtm1Her/J mice were immunized using a repetitive immunization multiple-sites strategy with KLH-conjugated peptides derived from the major outer membrane protein and the putative outer membrane protein 5 of Cpn. Mice were fed a high-fat diet and infected with Cpn twice during the 10-week diet period. Lesions were evaluated histologically; local and systemic immune responses were analyzed by immunohistochemistry of aorta samples and cytokine measurements in plasma samples and splenocyte supernatants.Results
Mice immunized with the combined Cpn peptide showed a greater reduction in lesion size compared to mice immunized with either epitope alone [54.7% vs 39.8% or 41.72%] and was also associated with a significant decrease in lesion area in descending aortas compared with those in controls (88.9% for combined Cpn peptide, 81.9% for MOMP peptide and 75.7% for Omp5, respectively). This effect was associated with a shift in the cellular composition of plaques towards decreased inflammatory cell and increased regulatory T-cell content. Additionally, the effect was also connected with decreased secretion of proinflammatory cytokines and increased production of anti-inflammatory cytokines demonstrated in plasma and in supernatant on stimulated spleen cells.Conclusions
Atherosclerotic lesion formation may be promoted by Cpn infection in the presence of a high-fat diet, and reduced by immunization with the combined Cpn peptide. The combined peptide has more potential than either epitope alone in reducing atherosclerotic lesion development through Treg expansion. 相似文献69.
Maria M. James Oliver Laeyendecker Jin Sun Donald R. Hoover Caroline E. Mullis Matthew M. Cousins Thomas Coates Richard D. Moore Gabor D. Kelen Mary Glenn Fowler Johnstone J. Kumwenda Lynne M. Mofenson Newton I. Kumwenda Taha E. Taha Susan H. Eshleman 《PloS one》2013,8(2)
Introduction
The Post-exposure Prophylaxis in Infants (PEPI)-Malawi trial evaluated infant antiretroviral regimens for prevention of post-natal HIV transmission. A multi-assay algorithm (MAA) that includes the BED capture immunoassay, an avidity assay, CD4 cell count, and viral load was used to identify women who were vs. were not recently infected at the time of enrollment (MAA recent, N = 73; MAA non-recent, N = 2,488); a subset of the women in the MAA non-recent group known to have been HIV infected for at least 2 years before enrollment (known non-recent, N = 54). Antibody maturation and viral diversification were examined in these women.Methods
Samples collected at enrollment (N = 2,561) and 12–24 months later (N = 1,306) were available for serologic analysis using the BED and avidity assays. A subset of those samples was used for analysis of viral diversity, which was performed using a high resolution melting (HRM) diversity assay. Viral diversity analysis was performed using all available samples from women in the MAA recent group (61 enrollment samples, 38 follow-up samples) and the known non-recent group (43 enrollment samples, 22 follow-up samples). Diversity data from PEPI-Malawi were also compared to similar data from 169 adults in the United States (US) with known recent infection (N = 102) and known non-recent infection (N = 67).Results
In PEPI-Malawi, results from the BED and avidity assays increased over time in the MAA recent group, but did not change significantly in the MAA non-recent group. At enrollment, HIV diversity was lower in the MAA recent group than in the known non-recent group. HRM diversity assay results from women in PEPI-Malawi were similar to those from adults in the US with known duration of HIV infection.Conclusions
Antibody maturation and HIV diversification patterns in African women provide additional support for use of the MAA to identify populations with recent HIV infection. 相似文献70.
Yu-Tao Xiang Robert W. Buchanan Gabor S. Ungvari Helen F. K. Chiu Kelly Y. C. Lai You-Hong Li Tian-Mei Si Chuan-Yue Wang Edwin H. M. Lee Yan-Ling He Shu-Yu Yang Mian-Yoon Chong Ee-Heok Kua Senta Fujii Kang Sim Michael K. H. Yong Jitendra K. Trivedi Eun-Kee Chung Pichet Udomratn Kok-Yoon Chee Norman Sartorius Chay-Hoon Tan Naotaka Shinfuku 《PloS one》2013,8(6)