28 research outputs found
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Eremantholide C from aerial parts of Lychnophora trichocarpha, as drug candidate: fraction absorbed prediction in humans and BCS permeability class determination
Late Pleistocene glacial transitions in North America altered major river drainages, as revealed by deep-sea sediment
Routes of Drug Administration
Systemic absorption of a drug depends on its physicochemical properties, the nature of the dosage form on which it is included and the anatomical and physiological characteristics of the site of absorption. These considerations are important on the biopharmaceutical production and evaluation of drugs: the design of the dosage forms requires a deep knowledge of the physiological and pathological factors that affect drug absorption for guarantying the therapeutic efficacy and to avoid possible drug-drug and drug-nutrient interactions.Fil: Ruiz, María Esperanza. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Scioli Montoto, Sebastián. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin
Mapping and interpreting a decision-making framework for the implicit managerial theory in the Arab Gulf States
This article developed an empirical design to examine the direct effects of four dimensions of the strategic decision-making process (SDMP) on the organizational innovation in the context of cultural value characteristics of executive managers in Qatar. The study used the cultural relativity theory to explain and advance hypotheses regarding the associations between SDMP dimensions, culture attributes, and innovation performance in an input-process-outcome model. To test the raised research hypotheses of the proposed framework, the methodology of structural equation models was used. Based on quantitative evidence of 140 Qatari public and private organizations, the results demonstrated the following three major issues: (1) strategic decision-making practices have a direct and more significant impact on process innovation performance than product/service innovation performance, (2) innovation performance is both process and context specific, and (3) certain contextualizing constructs verify a particular cultural orientation. The Author(s) 2014.Scopu
Drug Delivery Approaches in Addressing Clinical Pharmacology-Related Issues: Opportunities and Challenges
From Drug Delivery Systems to Drug Release, Dissolution, IVIVC, BCS, BDDCS, Bioequivalence and Biowaivers
This is a summary report of the conference on drug absorption and bioequivalence issues held in Titania Hotel in Athens (Greece) from the 28(th) to the 30(th) of May 2009. The conference included presentations which were mainly divided into three sections. The first section focused on modern drug delivery systems such as polymer nanotechnology, cell immobilization techniques to deliver drugs into the brain, nanosized liposomes used in drug eluting stents, encapsulation of drug implants in biocompatible polymers, and application of differential scanning calorimetry as a tool to study liposomal stability. The importance of drug release and dissolution were also discussed by placing special emphasis on camptothecins and oral prolonged release formulations. The complexity of the luminal environment and the value of dissolution in lyophilized products were also highlighted. The second session of the conference included presentations on the Biopharmaceutics Classification Scheme (BCS), the Biopharmaceutics Drug Disposition Classification System (BDDCS), and the role of transporters in the classification of drugs. The current status of biowaivers and a modern view on non-linear in vitro-in vivo (IVIVC) correlations were also addressed. Finally, this section ended with a special topic on biorelevant dissolution media and methods. The third day of the conference was dedicated to bioequivalence. Emphasis was placed on high within-subject variability and its impact on study design. Two unresolved issues of bioequivalence were also discussed: the use of generic antiepileptic drugs and the role of metabolites in bioequivalence assessment. Finally, the conference closed with a presentation of the current regulatory status of WHO and EMEA