124 research outputs found

    Possible Beneficial Effect of Exercise, by Reducing Oxidative Stress, on the Incidence of Preeclampsia

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    We hypothesize that regular exercise enhances antioxidative enzymes in pregnant women, which reduce oxidative stress and, thus, the incidence of preeclampsia. Oxidative stress with enhanced lipid peroxide formation could lead to endothelial dysfunction in preeclampsia. Other conditions, such as increased transferrin saturation and decreased iron-binding capacity, directly and indirectly promote the process of oxidative stress and subsequent endothelial dysfunction. Exercise increases oxidative metabolism and produces a prooxidant environment. This acidic environment during exercise (at or beyond anaerobic threshold) promotes oxygen release from hemoglobin and increases in PO2 in tissues, as well as releases iron from transferrin. When exercise is repeated regularly, the body promptly adjusts so that oxidative stress is eliminated or reduced. The body's adaptations to a regular exercise habit seem to have an antioxidant effect. In humans, training effects have been identified with an enhanced activity of antioxidative enzymes. Another concerted adaptation that regular exercise brings to women's bodies is resistance against production of prooxidants by increasing the number of mitochondria. Equally important is a training effect that decreases susceptibility to lipid peroxidation. Evidence suggests that physically active women are less likely to develop preeclampsia. In theory, intracellular and extracellular conditions resulting from regular exercise should counteract the enhancement of oxidative stress, thus interfering with the process leading to endothelial dysfunction. This position paper describes a hypothesis and includes a brief review of exercise physiology and biochemical research in preeclampsia. Unlike other preventive treatments, such as aspirin or calcium supplements, a regular exercise habit leads to a positive and healthy lifestyle without concern of side effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63167/1/152460901317193558.pd

    Pseudomonas aeruginosa PilY1 Binds Integrin in an RGD- and Calcium-Dependent Manner

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    PilY1 is a type IV pilus (tfp)-associated protein from the opportunistic pathogen Pseudomonas aeruginosa that shares functional similarity with related proteins in infectious Neisseria and Kingella species. Previous data have shown that PilY1 acts as a calcium-dependent pilus biogenesis factor necessary for twitching motility with a specific calcium binding site located at amino acids 850–859 in the 1,163 residue protein. In addition to motility, PilY1 is also thought to play an important role in the adhesion of P. aeruginosa tfp to host epithelial cells. Here, we show that PilY1 contains an integrin binding arginine-glycine-aspartic acid (RGD) motif located at residues 619–621 in the PilY1 from the PAK strain of P. aeruginosa; this motif is conserved in the PilY1s from the other P. aeruginosa strains of known sequence. We demonstrate that purified PilY1 binds integrin in vitro in an RGD-dependent manner. Furthermore, we identify a second calcium binding site (amino acids 600–608) located ten residues upstream of the RGD. Eliminating calcium binding from this site using a D608A mutation abolished integrin binding; in contrast, a calcium binding mimic (D608K) preserved integrin binding. Finally, we show that the previously established PilY1 calcium binding site at 851–859 also impacts the protein's association with integrin. Taken together, these data indicate that PilY1 binds to integrin in an RGD- and calcium-dependent manner in vitro. As such, P. aeruginosa may employ these interactions to mediate host epithelial cell binding in vivo

    Lifetime measurement in excited and yrast superdeformed bands in Hg194

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    Nuclear level lifetimes have been measured in two superdeformed bands in Hg194 using the Doppler-shift attenuation method. Average transition quadrupole moments derived from the lifetimes of an excited and yrast superdeformed bands are Qt=17.6(30) and 17.2(20)eb, respectively. The Doppler shifts of the excited band relative to the yrast band indicate a slight difference in quadrupole moments [+4(5)%], assuming similar side feeding..ul2 These results imply that the second well is stable and rigid with respect to the particle excitation responsible for this excited band

    Effect of garlic on cardiovascular disorders: a review

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    Garlic and its preparations have been widely recognized as agents for prevention and treatment of cardiovascular and other metabolic diseases, atherosclerosis, hyperlipidemia, thrombosis, hypertension and diabetes. Effectiveness of garlic in cardiovascular diseases was more encouraging in experimental studies, which prompted several clinical trials. Though many clinical trials showed a positive effect of garlic on almost all cardiovascular conditions mentioned above, however a number of negative studies have recently cast doubt on the efficary of garlic specially its cholesterol lowering effect of garlic. It is a great challenge for scientists all over the world to make a proper use of garlic and enjoy its maximum beneficial effect as it is the cheapest way to prevent cardiovascular disease. This review has attempted to make a bridge the gap between experimental and clinical study and to discuss the possible mechanisms of such therapeutic actions of garlic

    Anisotropic nanomaterials: structure, growth, assembly, and functions

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    Comprehensive knowledge over the shape of nanomaterials is a critical factor in designing devices with desired functions. Due to this reason, systematic efforts have been made to synthesize materials of diverse shape in the nanoscale regime. Anisotropic nanomaterials are a class of materials in which their properties are direction-dependent and more than one structural parameter is needed to describe them. Their unique and fine-tuned physical and chemical properties make them ideal candidates for devising new applications. In addition, the assembly of ordered one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) arrays of anisotropic nanoparticles brings novel properties into the resulting system, which would be entirely different from the properties of individual nanoparticles. This review presents an overview of current research in the area of anisotropic nanomaterials in general and noble metal nanoparticles in particular. We begin with an introduction to the advancements in this area followed by general aspects of the growth of anisotropic nanoparticles. Then we describe several important synthetic protocols for making anisotropic nanomaterials, followed by a summary of their assemblies, and conclude with major applications
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