Current Pharmaceutical Analysis - Volume 3, Issue 3, 2007

Many approaches have been applied in biological and clinical studies aimed at simultaneously monitoring the expression of a large number of genes and at identifying the gene expression patterns associated with specific cell types. In the last decade, microarrays are emerged as an innovative tool to detect differentially expressed genes as disease-specific markers and to cluster the co-expressed genes regulating the molecular interactions. In fact, microarrays have been widely used for tumour diagnosis and classification, prediction of prognoses and treatment, pharmaceutical safety assessment, and understanding of molecular mechanisms, biochemical pathways, and gene networks. Besides the clinical relevance and the wide application of this technology, several problems remain to be addressed. This review illustrates the current and future directions of the microarray platform, and highlights the successes and strengths, as well as the shortcomings and limitations of this technology. An overview of microarray impact on the ocular and craniofacial diseases is provided.

Drugs produced using recombinant gene technology often contain nucleic acids (DNA) as impurities. Such contaminants must be removed from solutions used for injection, because the influence of such DNA on the living body has not been fully clarified. Various techniques for DNA removal described in the patent literature are not broadly applicable, as they are tailored to meet specific product requirements. To remove DNA from a solution of high-molecular weight compounds, such as proteins, the adsorption method has proven to be most effective. This review intends to discuss various methods of chromatographic removal and separation of DNA from protein solutions using cationic polymer adsorbents. We will first discuss chromatographic properties of various DNA-specific polymer adsorbents, and then describe effects of adsorbent's pore size, its amino-group content, its surface pKa value, and buffer's condition on removal of DNA from a protein solution. Finally, we will discuss how to optimize a method of removal DNA without affecting the recovery of important compounds, such as proteins.

In support of individualizing antiretroviral treatment by combining therapeutic drug monitoring (TDM) and HIV resistance tests, numerous assays have been reported in the literature in an attempt to optimize treatment outcomes. These assays vary with regard to analysis method of separation and detection such as using high performance liquid chromatography (HPLC) coupled to mass tandem spectrometry (HPLC/MS or HPLC/MSMS) or ultraviolet spectrometry (HPLC/UV). To prepare plasma samples prior to analysis, clinical samples are subject to chemical procedures including solid phase extraction (SPE), liquid-liquid extraction (LLE), and protein precipitation (PP). Information searches were performed using database searching tools such as PubMed, MEDLINE, Web of Science, and EMBASE using the key words protease inhibitors, HIV, assay, quantification, determination, therapeutic drug monitoring and pharmacokinetics. Publications were reviewed and the data categorized by the specific protease inhibitor, the limit of quantification (LOQ), the type of assay, chromatographic conditions, sample preparation, and total assay run time. The analytical methods summarized in the review reflect the timeframe since the PI were introduced, their eventual combination with ritonavir, transitioning toward once or twice daily dosing and more recently their use in simplified regimes for chronic dosing. As antiretrovirals are introduced into developing countries additional considerations related to drug quality and potency may require that laboratories adapt these assays in support of clinical pharmacology research and patient monitoring.

Beyond doubt, nanobioscience represents one of the most innovative concepts in current basic and applied research. Technological advances provided the essentials for this ongoing scientific revolution, by making possible the observation, investigation and manipulation of biomaterials down to single molecules. Time-resolved single molecule detection has become the method of choice to characterize structural transitions between different functional states of isolated biomolecules. The development of ultra-sensitive detection schemes also has a strong impact on bioanalysis, as the sensitivity of biochemical assays could be dramatically increased. Whenever the available amount of sample is the limiting factor for unambiguous diagnosis e.g. in medical diagnostics, bioanalytics with single molecule sensitivity can be expected to become even an enabling technology. In this review, we describe methodological requirements for ultra- sensitive detection, and point out major advantages, in particular the novel information content.

Natriuretic peptides (NPs) are endogenous low molecular weight peptides known for their hypotensive activities. Due to their ability to induce both natriuresis (Na+ secretion) and diuresis, in fact, these peptides can profoundly decrease the body haemodynamic load, an effect which represents a main goal for all therapies aiming at improving the health of those subjects affected by different forms of heart and kidney failure. Over the years, many evidences have been provided for the involvement of NPs in the control of different cardiovascular parameters both in physiological and pathological conditions. This has led many researchers to test the possible therapeutic effects of different NPs and the pharmacological industries to develop exogenous NPs forms with a higher activity. This review aims then at summarizing the current knowledge about the therapeutic and clinical applications of NPs, also considering “atypical” NPs and the problems yet to be solved.

This study evaluated the feasibility of measuring HSA-drug binding affinity by ordinary (free solution) method. NMR is used to identify where a drug binds. An HSA-immobilized column and mimic ion-exchange columns were developed to measure HSA-drug binding affinity. The correlation between capacity ratios (log k) measured using these columns and HSA-drug binding affinity (log nK) was not perfect. The log k values measured using the mimic ion-exchangers well correlated with log nK values measured by a modified Hummer-Dreyer method with purified HSA. The log k (log KHSA) of basic drugs correlated well with the log nK values measured by the modified Hummer-Dreyer method, but not for the acidic drugs. Simple measurement as the percent concentration of bound drug is another matter. Computational chemical prediction methods were proposed. One uses the molecular properties of drugs. Another involves the direct calculation of binding energy required using model phases. Further study is necessary to develop quick measurement and prediction method to accelerate the drug discovery process.

Cyclosporine A ophthalmic solutions have recently emerged as an effective treatment for vernal keratoconjunctivitis (VKC). Cyclosporine A is known to have multiple inhibitory effects on T-cells, and allergic conjunctivitis models have shown that cyclosporine A eye drops can effectively inhibit T-cell-mediated eosinophil and neutrophil migration. Inhibitory effects of cyclosporine A on other inflammatory cells have also been documented. Release of histamine and cytokines from mast cells was shown to be inhibited by cyclosporine A and cyclosporine A eye drops were able to inhibit histamine release and migration of inflammatory cells in allergic conjunctivitis models mediated by mast cells. Cyclosporine A has also been reported to induce eosinophil apoptosis and block the ability of these cells to release eosinophil cationic protein (ECP). In neutrophils, cyclosporine A can inhibit the release of myeloperoxidase (MPO) and reactive oxygen species. In fibroblasts, cyclosporine A has been demonstrated to inhibit proliferation and pro-collagen production. In vitro, cyclosporine A has variable effects on inflammatory cells, underscoring the need for further experimentation to elucidate the full range of its cytologic effects and their relation to therapeutic outcome. The diverse inhibitory effects of cyclosporine A on inflammatory cells clearly underlie the ability of this drug to alleviate the symptoms of VKC.