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141.
Han Y Randell E Vasdev S Gill V Gadag V Newhook LA Grant M Hagerty D 《Molecular and cellular biochemistry》2007,305(1-2):123-131
The reactive aldehydes methylglyoxal and glyoxal, arise from enzymatic and non-enzymatic degradation of glucose, lipid and
protein catabolism, and lipid peroxidation. In Type 1 diabetes mellitus (T1DM) where hyperglycemia, oxidative stress, and
lipid peroxidation are common, these aldehydes may be elevated. These aldehydes form advanced glycation end products (AGEs)
with proteins that are implicated in diabetic complications. We measured plasma methylglyoxal and glyoxal in young, complication-free
T1DM patients and assessed activity of the ubiquitous membrane enzyme, Na+/K+ ATPase. A total of 56 patients with TIDM (DM group), 6–22 years, and 18 non-diabetics (ND group), 6–21 years, were enrolled.
Mean plasma A1C (%) was higher in the DM group (8.5 ± 1.3) as compared to the ND group (5.0 ± 0.3). Using a novel liquid chromatography-mass
spectrophotometry method, we found that mean plasma methylglyoxal (nmol/l) and glyoxal levels (nmol/l), respectively, were
higher in the DM group (841.7 ± 237.7, 1051.8 ± 515.2) versus the ND group (439.2 ± 90.1, 328.2 ± 207.5). Erythrocyte membrane
Na+/K+ ATPase activity (nmol NADH oxidized/min/mg protein) was elevated in the DM group (4.47 ± 0.98) compared to the ND group (2.16 ± 0.59).
A1C correlated with plasma methylglyoxal and glyoxal, and both aldehydes correlated with each other. A high correlation of
A1C with Na+/K+ ATPase activity, and a regression analysis showing A1C as a good predictor of activity of this enzyme, point to a role for
glucose in membrane alteration. In complication-free patients, increased plasma methylglyoxal, plasma glyoxal, and erythrocyte
Na+/K+ ATPase activity may foretell future diabetic complications, and emphasize a need for aggressive management. 相似文献
142.
Reduction of substrate by nitrogenase requires direct electron transfer from the Fe protein to the MoFe protein. Inhibition of nitrogenase activity in Methanococcus maripaludis occurs when the regulatory protein NifI1,2 binds the MoFe protein. This inhibition is relieved by 2-oxoglutarate. Here we present evidence that NifI1,2 binding prevents association of the two nitrogenase components. Increasing amounts of Fe protein competed with NifI1,2, decreasing its inhibitory effect. NifI1,2 prevented the co-purification of MoFe protein with a mutant form of the Fe protein that forms a stable complex with the MoFe protein, and NifI1,2 was unable to bind to an -stabilized Fe protein:MoFe protein complex. NifI1,2 inhibited ATP- and MoFe protein-dependent oxidation of the Fe protein, and 2OG relieved this inhibition. These results support a model where NifI1,2 competes with the Fe protein for binding to MoFe protein and prevents electron transfer. 相似文献
143.
Bruenger AJ Smith SL Sands WA Leigh MR 《Journal of strength and conditioning research / National Strength & Conditioning Association》2007,21(2):492-499
The purpose of this study was to validate the accuracy and reliability of the Weightlifting Video Overlay System (WVOS) used by coaches and sport biomechanists at the United States Olympic Training Center. Static trials with the bar set at specific positions and dynamic trials of a power snatch were performed. Static and dynamic values obtained by the WVOS were compared with values obtained by tape measure and standard video kinematic analysis. Coordinate positions (horizontal [X] and vertical [Y]) were compared on both ends (left and right) of the bar. Absolute technical error of measurement between WVOS and kinematic values were calculated (0.97 cm [left X], 0.98 cm [right X], 0.88 cm [left Y], and 0.53 cm [right Y]) for the static data. Pearson correlations for all dynamic trials exceeded r = 0.88. The greatest discrepancies between the 2 measuring systems were found to occur when there was twisting of the bar during the performance. This error was probably due to the location on the bar where the coordinates were measured. The WVOS appears to provide accurate position information when compared with standard kinematics; however, care must be taken in evaluating position measurements if there is a significant amount of twisting in the movement. The WVOS appears to be reliable and valid within reasonable error limits for the determination of weightlifting movement technique. 相似文献
144.
145.
Diesel exhaust particulate matter induces multinucleate cells and zinc transporter-dependent apoptosis in human airway cells 总被引:1,自引:0,他引:1
Ackland ML Zou L Freestone D van de Waasenburg S Michalczyk AA 《Immunology and cell biology》2007,85(8):617-622
The cellular effects of biodiesel emissions particulate matter (BDEP) and petroleum diesel emissions particulate matter (PDEP) were compared using a human airway cell line, A549. At concentrations of 25 microg/ml, diesel particulate matter induced the formation of multinucleate cells. In cells treated with a mixture of 80% PDEP:20% BDEP, 52% of cells were multinucleate cells compared with only 16% of cells treated with 20% PDEP:80% BDEP with a background multinucleate rate of 7%. These results demonstrate a causal relation between the formation of multinucleate cells and exposure to exhaust particulate matter, in particular diesel exhaust. Exposure of A549 cells to PDEP induced apoptosis, seen by active caspase-3 expression and the presence of cleaved pancytokeratin. PDEP exhaust was a much stronger inducer of cellular death through apoptosis than BDEP. There was an eightfold increase in the expression of SLC30A3 (zinc transporter-3 or ZnT3) in cells exposed to 80% PDEP:20% BDEP compared to untreated cells. The increase in ZnT3 expression seen in apoptotic cells following PDEP suggests a role for this zinc transporter in the apoptotic pathway, possibly through controlling zinc fluxes. As exposure to diesel exhaust particles is associated with asthma and apoptosis in airway cells, diesel exhaust particles may directly contribute to asthma by inducing epithelial cell death through apoptotic pathway. 相似文献
146.
Debra L Fisk Leigh C LattaIV Roland A Knapp Michael E Pfrender 《BMC evolutionary biology》2007,7(1):22
Background
Introduced species can have profound effects on native species, communities, and ecosystems, and have caused extinctions or declines in native species globally. We examined the evolutionary response of native zooplankton populations to the introduction of non-native salmonids in alpine lakes in the Sierra Nevada of California, USA. We compared morphological and life-history traits in populations of Daphnia with a known history of introduced salmonids and populations that have no history of salmonid introductions. 相似文献147.
Bainbridge J Madden L Essex D Binks M Malhotra R Paleolog EM 《Arthritis research & therapy》2007,9(6):R127
The enzyme methionine aminopeptidase-2 (MetAP-2) is thought to play an important function in human endothelial cell proliferation,
and as such provides a valuable target in both inflammation and cancer. Rheumatoid arthritis (RA) is a chronic inflammatory
disease associated with increased synovial vascularity, and hence is a potential therapeutic target for angiogenesis inhibitors.
We examined the use of PPI-2458, a selective non-reversible inhibitor of MetAP-2, in disease models of RA, namely acute and
chronic collagen-induced arthritis (CIA) in mice. Whilst acute CIA is a monophasic disease, CIA induced with murine collagen
type II manifests as a chronic relapsing arthritis and mimics more closely the disease course of RA. Our study showed PPI-2458
was able to reduce clinical signs of arthritis in both acute and chronic CIA models. This reduction in arthritis was paralleled
by decreased joint inflammation and destruction. Detailed mechanism of action studies demonstrated that PPI-2458 inhibited
human endothelial cell proliferation and angiogenesis in vitro, without affecting production of inflammatory cytokines. Furthermore, we also investigated release of inflammatory cytokines
and chemokines from human RA synovial cell cultures, and observed no effect of PPI-2458 on spontaneous expression of cytokines
and chemokines, or indeed on the angiogenic molecule vascular endothelial growth factor (VEGF). These results highlight MetAP-2
as a good candidate for therapeutic intervention in RA. 相似文献
148.
Chua Jia Wang Madden Leigh Lim Sophia Beng Hui Philips Anthony R. J. Becker David L. 《Molecular and cellular biochemistry》2022,477(1):295-305
Molecular and Cellular Biochemistry - Despite many advances across the surgical sciences, post-surgical peritoneal adhesions still pose a considerable risk in modern-day procedures and are highly... 相似文献
149.
Jean-Marie Burel Sébastien Besson Colin Blackburn Mark Carroll Richard K. Ferguson Helen Flynn Kenneth Gillen Roger Leigh Simon Li Dominik Lindner Melissa Linkert William J. Moore Balaji Ramalingam Emil Rozbicki Aleksandra Tarkowska Petr Walczysko Chris Allan Josh Moore Jason R. Swedlow 《Mammalian genome》2015,26(9-10):441-447
150.
Evolutionary change in testes tissue composition among experimental populations of house mice
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Renée C. Firman Francisco Garcia‐Gonzalez Evan Thyer Samantha Wheeler Zayaputeri Yamin Michael Yuan Leigh W. Simmons 《Evolution; international journal of organic evolution》2015,69(3):848-855
Theory assumes that postcopulatory sexual selection favors increased investment in testes size because greater numbers of sperm within the ejaculate increase the chance of success in sperm competition, and larger testes are able to produce more sperm. However, changes in the organization of the testes tissue may also affect sperm production rates. Indeed, recent comparative analyses suggest that sperm competition selects for greater proportions of sperm‐producing tissue within the testes. Here, we explicitly test this hypothesis using the powerful technique of experimental evolution. We allowed house mice (Mus domesticus) to evolve via monogamy or polygamy in six replicate populations across 24 generations. We then used histology and image analysis to quantify the proportion of sperm‐producing tissue (seminiferous tubules) within the testes of males. Our results show that males that had evolved with sperm competition had testes with a higher proportion of seminiferous tubules compared with males that had evolved under monogamy. Previously, it had been shown that males from the polygamous populations produced greater numbers of sperm in the absence of changes in testes size. We thus provide evidence that sperm competition selects for an increase in the density of sperm‐producing tissue, and consequently increased testicular efficiency. 相似文献