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V López

Publications and source records attributed to V López.

45 records · Page 3Linked to original sources
PubMedDate not supplied

Manganese-dependent inhibition of human liver arginase by borate.

Full activation of human liver arginase (EC 3.5.3.1), by incubation with 5 mM Mn2+ for 10 min at 60 degrees C, resulted in increased Vmax and a higher sensitivity of the enzyme to borate inhibition, with no change in the K(m) for arginine. Borate behaved as an S-hyperbolic I-hyperbolic non-competitive inhibitor and had no effect on the interaction of the enzyme with the competitive inhibitors L-ornithine (Ki = 2 +/- 0.5 mM), L-lysine (Ki = 2.5 +/- 0.4 mM), and guanidinium chloride (Ki = 100 +/- 10 mM). The pH dependence of the inhibition was consistent with tetrahedral B(OH)4- being the inhibitor, rather than trigonal B(OH)3. We suggest that arginase activity is associated with a tightly bound Mn2+ whose catalytic action may be stimulated by addition of a more loosely bound Mn2+, to generate a fully activated enzyme form. The Mn2+ dependence and partial character of borate inhibition are explained by assuming that borate binds in close proximity to the loosely bound Mn2+ and interferes with its stimulatory action. Although borate protects against inactivation of the enzyme by diethyl pyrocarbonate (DEPC), the DEPC-sensitive residue is not considered as a ligand for borate binding, since chemically modified species, which retain about 10% of enzymatic activity, were also sensitive to the inhibitor.

Arginase↗
PubMedDate not supplied

[Smoking prevention as a political issue].

The causes of many health problems such as smoking are beyond individual action. To change them requires the development of interventions dealing with the social factors that cause them, interventions of a political nature. In this paper we review for Spain public policies influencing smoking, with an emphasis on those with greater potential impact (fiscal policies to increase price, and those controlling the promotion and publicity of tobacco products), as well as the role of different government levels in regulation (local, regional central and European). The role of the Central government and of the European Union are crucial today in Spain. Some aspects influencing the adoption of smoking prevention policies (problem definition, private interests, and ideology) are also analyzed, as well as the need for a strategic coalition to promote them.

Global Health↗
PubMedDate not supplied

[Percutaneous transluminal angioplasty in vascular by-passes].

Results from 21 cases of percutaneous transluminal angioplasties as a treatment of stenosed vascular by-pass from 16 patients, are presented. The technique took place in 10 cases at the aorto-femoral area, in others 10 cases at the popliteal-femoral area and, in the last one, at the carotid-subclavian area. Preliminary results were successful in all cases (100%). Follow-up showed a better long-term results at the aorto-femoral level. Considering the satisfactory results and also considering that, in case of negative results or re-stenosis, other surgical techniques could be performed, we conclude that the percutaneous transluminal angioplasty should be the first treatment for such of injuries.

Anastomosis, Surgical↗