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Numerous Reasons (numerous + reason)

Distribution by Scientific Domains
Medical Sciences60%

Selected Abstracts

A simple pharmacokinetics subroutine for modeling double peak phenomenon

BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 3 2006
Ahmad Mirfazaelian
Abstract Double peak absorption has been described with several orally administered drugs. Numerous reasons have been implicated in causing the double peak. DRUG-KNT,a pharmacokinetic software developed previously for fitting one and two compartment kinetics using the iterative curve stripping method,was modified and a revised subroutine was incorporated to solve double-peak models. This subroutine considers the double peak as two hypothetical doses administered with a time gap. The fitting capability of the presented model was verified using four sets of data showing double peak profiles extracted from the literature (piroxicam, ranitidine, phenazopyridine and talinolol). Visual inspection and statistical diagnostics showed that the present algorithm provided adequate curve fit disregarding the mechanism involved in the emergence of the secondary peaks. Statistical diagnostic parameters (RSS, AIC and R2) generally showed good fitness in the plasma profile prediction by this model. It was concluded that the algorithm presented herein provides adequate predicted curves in cases of the double peak phenomenon. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Clinical presentation and management of antibody-induced failure of botulinum toxin therapy

MOVEMENT DISORDERS, Issue S8 2004
Dirk Dressler MD
Abstract Therapy with botulinum toxin (BT) can fail due to numerous reasons, including failure due to formation of antibodies against BT (BT-AB, AB-TF). AB-TF is a secondary therapy failure, i.e. it occurs during the course of an ongoing BT therapy. It can be subjective or objective, temporary or permanent, and partial or complete. Complete AB-TF is usually preceded by injection series with partial AB-TF in which the therapeutic effect is reduced in its intensity and duration. AB-TF usually occurs within 2 or 3 years after initiation of BT therapy. After 4 years it is rare. BT-AB are neutralising or blocking by definition, i.e. they are directly interfering with BT's biological mechanism of action. Non-neutralizing or non-blocking antibodies occur. BT-AB can be detected by the mouse diaphragm assay, the mouse protection assay, and by patient-based tests such as the sternocleidomastoid test, the extensor digitorum brevis test, and the frowning test. Enzyme-linked immunosorbent assays (ELISA) have a low specificity and a low sensitivity for detection of BT-AB. BT-AB titres drop spontaneously after cessation of BT therapy but latencies are too long to be compatible with an effective BT therapy. BT dosage increase can be successful to overcome AB-TF when AB-TF is partial and when BT-AB titres are low. Usage of alternative BT type A preparations fail to overcome AB-TF. Alternative BT types, such as BT type B and BT type F, are initially successful in AB-TF, but stimulate formation of antibodies against the alternative BT types after few applications. BT-AB reduction with immunosuppressants and inactivation of BT-AB by intravenous immunoglobuline application has not yet been achieved. Extraction of BT-AB by plasmapheresis and immunoadsorption is possible but is associated with substantial logistic problems. Prevention of BT-AB formation, therefore, is of paramount importance. Identified risk factors for BT-AB formation must be taken into account when BT therapy is planned. The most interesting perspective seems to be the development of new BT preparations with reduced antigenicity. © 2004 Movement Disorder Society [source]

CANDIDATE PERSISTENCE AND PERSONALITY TEST PRACTICE EFFECTS: IMPLICATIONS FOR STAFFING SYSTEM MANAGEMENT

PERSONNEL PSYCHOLOGY, Issue 2 2010
JOHN P. HAUSKNECHT
Candidates persist in selection settings for numerous reasons, prompting several concerns regarding staffing-system management. Predictors of the propensity to retest and personality test practice effects were investigated among a sample of 15,338 candidates who applied for supervisory positions (and 357 who repeated the selection process) over a 4-year period with a large organization in the service industry. Results reveal greater likelihood of retesting among internal candidates and overall evidence of small-to-moderate personality test practice effects. Compared to passing candidates who retested for various reasons, failing candidates pursued alternative response strategies upon retesting and generated dimension-level practice effects that reached .40 to .60, whereas passing candidates generally replicated their initial profiles. For several subscales, low initial scores were associated with practice effects that exceeded a full standard deviation. Implications for research, practice, and policy are discussed. [source]

Is grass biomethane a sustainable transport biofuel?

BIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 3 2010
Nicholas E. Korres
Abstract Grassland is a beneficial landscape for numerous reasons including potential to sequester carbon in the soil. Cross compliance dictates that grassland should not be converted to arable land; this is particularly interesting in Ireland where 91% of agricultural land is under grass. Biogas generated from grass and further upgraded to biomethane has been shown to offer a better energy balance than first-generation liquid biofuels indigenous to Europe. The essential question is whether the gaseous biofuel meets the EU sustainability criteria of 60% greenhouse gas emission savings. The base-case scenario investigated included: utilization of electricity from the grid; over-sizing heated digestion tanks to hold digestate in the winter period; vehicular efficiency 82% of that of a diesel vehicle; and no allowance for carbon sequestration. The analysis of the base case showed a reduction in emissions of 21.5%. However by varying the system, using electricity from wind, improving digester configuration, and by using a vehicle optimized for gaseous fuel, a reduction of 54% was evaluated. Furthermore allowing for 0.6 t carbon sequestration per hectare per annum the reduction increased to 75%. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd [source]

Infectious causes of cancer: an evolving educational saga

CLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2009
G. Pappas
Scientific interest in the aetiological relationship between infectious diseases and cancer is constantly increasing for numerous reasons. First, increased numbers of neoplasias have been definitely aetiologically correlated with specific pathogens. Second, the pathways that lead to carcinogenesis have shed light on numerous important cellular processes. Third, infection as a cause of cancer is preventable, and thus cancer is preventable, either at a primary stage by inhibition of infection or, secondarily, by inhibition of the carcinogenic process. The latter reason lies behind two of the major public health campaigns of recent years, namely vaccination for hepatitis B virus and human papilloma virus. [source]