Abstract: Chronic hypertension affects >1 billion people worldwide and >70 million people in the United States. Acute hypertensive episodes (AHE) are defined as severe spikes in blood pressure that may result in end-organ damage. Although AHE may arise independently as de novo events, they are more likely to occur in patients with pre-existing hypertension. One of the controversies regarding the clinical approach to AHE is the selection of anti-hypertensive medication. Depending on the clinical presentation of the patient and the threat of end-organ damage resulting from blood pressure elevation, appropriate and prompt treatment is warranted. There are multiple agents available for the management of hypertension. However, the greatest challenge lies in the acute care setting where the need exists for better initial and sustained control of blood pressure spikes. Many anti-hypertensive agents effectively lower blood pressure, yet only few have the capacity to achieve strict control of hypertension in the acute setting. Clevidipine butyrate is an ultra short-acting intravenous dihydropyridine calcium-channel blocker. Clevidipine has unique pharmacodynamic and pharmacokinetic properties that enable the fast, safe, and adequate reduction of blood pressure in hypertensive emergencies, with the ability to provide highly precise titration necessary to maintain a narrowly-defined target blood pressure range. Several recently published phase I, II, and III clinical studies have shown Clevidipine to be an effective blood pressure modulator in such capacity. ... Read more

Abstract: Drug transporters mediate the movement of endobiotics and xenobiotics across biological membranes in multiple organs and in most tissues. As such, they are involved in physiology, development of disease, drug pharmacokinetics, and ultimately the clinical response to a myriad of medications. Genetic variants in transporters cause population-specific differences in drug transport and are responsible for considerable inter-individual variation in physiology and pharmacotherapy. The purpose of this review is to provide a broad overview of how inherited variants in transporters are associated with disease etiology, disease state, and the pharmacological treatment of diseases. Given that there are thousands of published papers related to the interplay between transporter genetics and medicine, this review will provide examples that exemplify the broader focus of the literature. ... Read more

Abstract: Aphasia, a condition defined as the partial or complete loss of language function after brain damage, is one of the most devastating cognitive deficits produced by stroke lesions. Over the past decades, there have been great advances in the diagnosis and treatment of post-stroke language and communication deficits. In particular, the advent of functional brain imaging and other brain mapping methods has advanced our understanding of how the intact and lesioned brain takes over the activity of irretrievably damaged networks in aphasic patients. This review examines the contribution of these ancillary methods to elucidate the neural changes that take place to promote improvement of language function in early, late, and very late stages of recovery. Also, functional neuroimaging is helpful to identify brain areas involved in language recovery as well as to characterize the plastic reorganization of neural networks produced by scientifically-based language therapies and biological treatments (drugs, transcranial magnetic stimulation). ... Read more

Abstract: Inter-individual variation in drug response and adverse drug reactions (ADRs) are well known in medicine. This individual variation in drug response could be at least, in part, due to genetic diversity among individuals. Although substantial studies that connect genetic variants to inter-individual variation in drug response have been documented in several diseases such as cancer and heart diseases, such studies are slowly progressing in ophthalmology. In recent years, advancement in technologies has led to the identification of genes associated with several eye disorders. At the same time, some small-scale studies have demonstrated the association of various genotypes or haplotypes with response to drug therapies. However, its integration into clinical practice in ophthalmology is not possible at present. This is because there are many challenging questions that remain to be addressed. For instance, in the case of complex disorders a single gene study is not enough. Multiple genes, environmental factors, multiple single nucleotide polymorphisms (SNPs), and rare or low frequency variants may contribute to the disease and they must be considered. The functional aspects of many genetic variants are not known. This raises questions of their biological importance and their clinical usefulness. In addition, there are legal, ethical, and social issues that need to be regulated. Moreover, physicians and patients must be educated about the limitation and sensitivity of genetic testing. At present pharmacogenetic studies in ophthalmology are still in their infancy and do not suggest that a pharmacogenetic basis of drug development in ophthalmology is a concept that can yield immediate results, but can become a reality in the future. In this article an attempt has been made to summarize some of the recent small-scale pharmacogenetic studies on two major eye disorders, age-related macular degeneration (AMD) and glaucoma. ... Read more

Abstract: Nucleic acid-based aptamers have been shown as high-affinity ligands and potential antagonists of disease-associated proteins. Aptamers, isolated from combinatorial libraries by an iterative in vitro selection process, discriminate between closely related targets and are characterized by high specificity and low toxicity thus representing a valid alternative to antibodies to target specific proteins of biomedical interest. Moreover, they are non-immunogenic and can be easily stabilized by chemical modifications thus expanding their therapeutic potential. Here, we will focus on the structural and functional features of aptamers that have entered the clinical development pipeline together with those aptamers holding great potential as therapeutics in preclinical studies. The future perspectives of aptamers as therapeutics will be discussed as well. ... Read more

Abstract: Because most medicines have not been encountered by individuals of our species prior to treatment, it follows that treatment could uncover a previously silent genetic predisposition or could interact with a known genetic variation(s) to produce an unintended outcome. Pharmacogenetics encompasses the discovery, testing, and application of genetic variation as applied to therapeutic treatment and outcome. Two broad divisions of pharmacogenetics are recognized: pharmacokinetics, which describes genetic variations that affect drug metabolism, and pharmacodynamics which describes similar processes that have effects on drug targets, including downstream signaling pathways. The genetic mechanisms that underlie an altered drug response recapitulates most known sources of genomic variation. The most commonly encountered is sequence variation. This includes changes in the primary nucleotide sequence of coding, regulatory, and splice regions of a gene, the product of which affects, or is affected by, a drug. Less common forms of variability in the structure and function of the genome have also been found to underlie an individualized response to medicines. Among these are sequence variation in microRNA (miRNA) binding sites, which affects the ability of miRNA to regulate translation; pharmacoepigenetics, which examines heritable chromatin modifications; and copy number variation. Among the 158 currently registered pharmacogenetic clinical trials, the most frequent conditions or disease processes being studied are cancer, psychiatric disorders, and coagulation/thrombosis. From this observation, it is postulated that pharmacogenetics has its greatest potential for optimizing the use of drugs with a high rate of failure or adverse outcomes. ... Read more

Abstract: Background: We explored use of a canine model of heart failure (HF) for pharmacogenomic discovery, specifically analyzing response to beta blockers (BB). Methods: Dogs with HF that received BB (n=39) underwent genome-wide genotyping to test the association with changes in left ventricular (LV) volume and ejection fraction after treatment. Resulting candidate genes underwent RNA quantification in cardiac tissue from normal (n=5), placebo-HF (n=5), and BB-HF (n=7) dogs. Results: Three markers met whole-genome significance for association with improved LV end-systolic volume after BB therapy (each p<5x10^-7). RNA quantification of three candidate genes near these markers -- GUCA1B, RRAGD, and MRPS10 -- revealed that gene expression levels in BB-HF dogs were between that of placebo-HF dogs and normal dogs. Conclusion: Genome-wide pharmacogenomic screening in a canine model of HF suggests 3 novel BB response candidate loci. This approach is adaptable to discovering mechanisms of action for other drug therapies, and may be a useful strategy for identifying candidate genes for drug response in the pre-clinical setting. ... Read more

Abstract: Frequent failures of experimental medicines in clinical trials question current concepts for predicting drug-effects in the human body. Improving the probability for success in drug discovery requires a better understanding of cause-effect relationships at the organism, organ, tissue, cellular, and molecular levels, each having a different degree of complexity. Despite the longstanding realization that clinical and preclinical drug-effect information needs to be integrated for generating more accurate forecasts of drug-effects, a road map for linking these disparate sources of information currently does not exist. This review focuses on a possible approach for obtaining these relationships by analyzing causes and effects on the basis of the topology of network interaction systems that process information at the cellular and organ system levels. ... Read more

Abstract: Every new anti-cancer drug or drug combination is evaluated for safety and efficacy before being approved. Clinical development of cytotoxic anticancer drugs classically follows three main phases. Phase I trials represent the first administration of a new drug or combination to human beings. Their primary goal is to determine the recommended phase two dose and also to collect toxicity, pharmacokinetic and pharmacodynamic data. Phase II trials are screening studies aimed at identifying signals of anti-tumor activity in a specific tumor type and setting. Phase III trials aim to compare the efficacy of a new treatment with standard of care and can lead to regulatory approval when positive. The recent emergence of molecularly targeted agents has challenged the traditional developmental pathway for anti-cancer drugs. Using biomarker enriched patient populations has been successful for a few agents. Otherwise, new types of trials have been proposed for these agents in an attempt to elucidate their mechanism of action, such as phase 0 trials and "window of opportunity" trials. These two types of trials and the classical three phase trials are discussed in detail. ... Read more

Abstract: If those of us privileged enough to have the opportunity to work towards curing human diseases had the power to design the ideal therapeutic molecule, the question would be what selection criteria would we choose? Arguably, at the top of the list would be four mandatory properties: specificity, potency, tolerability, and universality. So it should come as no surprise the momentum associated with the field of small interfering RNA (siRNA)-induced RNA Interference (RNAi) therapeutics has gained strength, as these molecules have shown exceptional promise in fulfilling all of these requirements. Unfortunately, siRNAs are too large, too charged, and too rigid to passively diffuse across the cellular membrane and thereby require a delivery system to enter cells. Thus, since its conception of working in human cells, siRNA delivery remains THE 800 Pound Gorilla in the room. The main complication yet to overcome is engineering delivery systems that are safe and efficient in systemically delivering siRNA molecules to the diseased tissue and across the cellular membrane of target cells. Currently, encapsulating the siRNA in nanoparticle and liposomal systems has risen to become the standard of delivery approaches. While generally speaking these delivery platforms offer significant advancements, our laboratory is committed to generating alternative siRNA delivery technologies that avoid nanoparticle packaging and allow siRNA molecules to be delivered as single, soluble entities. This brief review discusses the first of these technologies, a Peptide Transduction Domain-dsRNA Binding Domain (PTD-DRBD) fusion protein that avidly binds to the siRNA backbone to mask the negative charge and uses the PTD for macromolecular cellular delivery. ... Read more