A comparative evaluation of open loop and closed loop drug administration strategies in the treatment of AIDS.

In recent years, many researchers in the field of biomedical sciences have made successful use of mathematical models to study, in a quantitative way, a multitude of phenomena such as those found in disease dynamics, control of physiological systems, optimization of drug therapy, economics of the preventive medicine and many other applications. The availability of good dynamic models have been providing means for simulation and design of novel control strategies in the context of biological events. This work concerns a particular model related to HIV infection dynamics which is used to allow a comparative evaluation of schemes for treatment of AIDS patients. The mathematical model adopted in this work was proposed by Nowak & Bangham, 1996 and describes the dynamics of viral concentration in terms of interaction with CD4 cells and the cytotoxic T lymphocytes, which are responsible for the defense of the organism. Two conceptually distinct techniques for drug therapy are analyzed: Open Loop Treatment, where a priori fixed dosage is prescribed and Closed Loop Treatment, where the doses are adjusted according to results obtained by laboratory analysis. Simulation results show that the Closed Loop Scheme can achieve improved quality of the treatment in terms of reduction in the viral load and quantity of administered drugs, but with the inconvenience related to the necessity of frequent and periodic laboratory analysis.

US Food and Drug Administration approval of generic versions of complex biologics: implications for the practicing physician using low molecular weight heparins

Low-molecular-weight heparins (LMWHs) have shown equivalent or superior efficacy and safety to unfractionated heparin as antithrombotic therapy for patients with acute coronary syndromes. Each approved LMWH is a pleotropic biological agent with a unique chemical, biochemical, biophysical and biological profile and displays different pharmacodynamic and pharmacokinetic profiles. As a result, LMWHs are neither equipotent in preclinical assays nor equivalent in terms of their clinical efficacy and safety. Previously, the US Food and Drug Administration (FDA) cautioned against using various LMWHs interchangeably, however recently, the FDA approved generic versions of LMWH that have not been tested in large clinical trials. This paper highlights the bio-chemical and pharmacological differences between the LMWH preparations that may result in different clinical outcomes, and also reviews the implications and challenges physicians face when generic versions of the original/innovator agents are approved for clinical use.

In vivo study of laser irradiation of fractionated drug administration based mechanism for effective photodynamic therapy in rat liver

Up-regulation of stress-activated proteins in cancer cells plays a protective role against photodynamic induced apoptosis. Post photodynamic therapy extracted normal rat liver tissue usually shows a fraction of surviving cells, the photodynamic resistant cells, residing in the necrotic region. To treat these photo-dynamic resistant cells a technique has been proposed based on fractionated drug administration of diluted photosensitizer, keeping the net concentration (5 mg/kg) constant, and subsequently varying drug light interval (DLI). Flourescence measurements were made for the presence of photosensitizer in a tissue. For qualitative analysis both histological and morphological studies were made. Although preliminary aim of this approach was not achieved but there were some interesting observation made i.e. for higher dilution of photosensitizer there was a sharp boundary between necrotic and normal portion of tissue. An increase in the absorption coefficient (alpha) from 2.7 -> 2.9 was observed as photosensitizer was diluted while the corresponding threshold dose (D (th)) persistently decreases from (0.10 -> 0.02) J/cm(2) when irradiated with a 635 nm laser fluence of 150 J/cm(2).

Chemotherapy patients' perceptions of drug administration safety

To explore chemotherapy patients' experiences of drug administration safety and to investigate the relationship between perceptions of risk and harm from error, staff safety practices, and patients' engagement in error prevention strategies.

Changes in volumetric BMD of radius and tibia upon antidepressant drug administration in young depressive patients

To determine longitudinal changes in trabecular volumetric BMD (vBMD) at tibia and radius in young depressive patients under antidepressants using pQCT.

Agriculture, Rural Development, Food and Drug Administration, and related agencies appropriations for 2011 : hearings before a Subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Eleventh Congress, second session /

Mode of access: Internet.

Agriculture, Rural Development, Food and Drug Administration, and related agencies appropriations for 2013 : hearings before a Subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Twelfth Congress, second session /

Shipping list no.: 2012-0266-P (pt. 1A), 2012-0262-P (pt. 1B), 2012-0267-P (pt. 1C), 2012-0317-P (pt. 2), 2013-0006 (pt. 3), 2013-0008-P (pt. 4), 2013-0027-P (pt. 5), 2013-0033-P (pt. 6), 2013-0042-P (pt. 7), 2013-0038-P (pt. 9).

Agriculture, Rural Development, Food and Drug Administration, and related agencies appropriations for 2012 : hearings before a Subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Twelfth Congress, first session /

Shipping list number: 2011-0276-P (pt. 1A), 2011-0274-P (pt. 1B), 2011-0283-P (pt. 1C), 2011-0318-P (pt. 2), 2011-0339-P (pt. 4), 2011-0366-P (pt. 5), 2011-0375-P (pt. 6), 2011-0367-P (pt. 7), 2011-0372-P (pt. 8), 2012-0014-P (pt. 9).

Interagency coordination in drug research and regulation. Hearings before the Subcommittee on Reorganization and International Organizations of the Committee on Government Operations, United States Senate, Eighty-eighth Congress, first session. Agency coordination study, pursuant to S. Res. 27, 88th Cong. Review of cooperation on drug policies among Food and Drug Administration, National Institutes of Health, Veterans' Administration, and other agencies. Mar. 20-June 26, 1963.

Mode of access: Internet.

Agriculture, Rural Development, Food and Drug Administration, and related agencies appropriations for 2005 : hearings before a subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Eighth Congress, second session /

Shipping list no.: 2004-0116-P (pts. 1A-B), 2004-0162-P (pt.2), 2004-0180-P (pt. 3), 2004-0204-P (pt. 4), 2004-0198-P (pt. 5), 2004-0199-P (pt. 6), 2004-0207-P (pt. 7), 2004-0208-P (pt. 8).

Agriculture, Rural Development, Food and Drug Administration, and related agencies appropriations for 2006 : hearings before a Subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Ninth Congress, first session /

Shipping list no. : 2005-0156-P (pt. 1A), 2005-0131-P (pt. 1B), 2005-0136-P (pt. 2), 2005-0172-P (pt. 3-5, 7), 2005-0185-P (pt. 6), 2005-0168-P (pt. 8), 2006-0066-P (pt. 9).