Absorption, distribution, metabolism and excretion pharmacogenomics of drugs of abuse

The genetics of multiple sclerosis: an up-to-date review

Multiple sclerosis (MS) is a prevalent inflammatory disease of the central nervous system that often leads to disability in young adults. Treatment options are limited and often only partly effective. The disease is likely caused by a complex interaction between multiple genes and environmental factors, leading to inflammatory-mediated central nervous system deterioration. A series of genomic studies have confirmed a central role for the immune system in the development of MS, including genetic association studies that have now dramatically expanded the roster of MS susceptibility genes beyond the longstanding human leukocyte antigen (HLA) association in MS first identified nearly 40 years ago. Advances in technology together with novel models for collaboration across research groups have enabled the discovery of more than 50 non-HLA genetic risk factors associated with MS. However, with a large proportion of the disease heritability still unaccounted for, current studies are now geared towards identification of causal alleles, associated pathways, epigenetic mechanisms, and gene-environment interactions. This article reviews recent efforts in addressing the genetics of MS and the challenges posed by an ever increasing amount of analyzable data, which is spearheading development of novel statistical methods necessary to cope with such complexity.

Long-term ketamine and ketamine plus alcohol treatments produced damages in liver and kidney

Ketamine is one of the common recreational drugs used in rave parties and it is frequently taken with alcohol. In spite of this, the potential toxicity of ketamine in liver and kidney has not been fully documented. In this study, ICR mice were treated for periods of 6, 16 and 28 weeks with 30 mg/kg ketamine injected daily intraperitoneally, and together with alcohol (0.5 ml of 10% alcohol for each mouse) during the last 4 weeks of the treatment periods. Our experimental results showed significant damage in liver, including fatty degeneration of liver cells, fibrosis and increase in liver glutamic oxaloacetic transaminase, proliferative cell nuclear antigen and lactate dehydrogenase after 16 weeks of treatment with ketamine. Hydropic degenerations of the kidney tubules were observed as early as 6 weeks of treatment. Long-term ketamine administration (28 weeks) led to atresia of glomeruli in the kidney. Proteinuria was confirmed in the 67% of the ketamine-treated animals after 28 weeks of treatment. It was apparent that ketamine when taken chronically (16 weeks of treatment and thereafter) affected both liver and kidney definitively. The damages in both liver and kidney of these mice were more severe when the animals were treated with both ketamine and alcohol.

Pharmacokinetics of ketamine and propofol combination administered as ketofol via continuous infusion in cats

The pharmacokinetics of the extemporaneous combination of low doses of ketamine and propofol, known as 'ketofol', frequently used for emergency procedures in humans to achieve safe sedation and analgesia was studied in cats. The study was performed to assess propofol, ketamine and norketamine kinetics in six female cats that received ketamine and propofol (1:1 ratio) as a loading dose (2 mg/kg each, IV) followed by a continuous infusion (10 mg/kg/h each, IV, 25 min of length). Blood samples were collected during the infusion period and up to 24 h afterwards. Drug quantification was achieved by HPLC analysis using UV-visible detection for ketamine and fluorimetric detection for propofol. The pharmacokinetic parameters were deduced by a two-compartment bolus plus infusion model for propofol and ketamine and a monocompartmental model for norketamine. Additional data were derived by a noncompartmental analysis. Propofol and ketamine were quantifiable in most animals until 24 and 8 h after the end of infusion, respectively. Propofol showed a long elimination half-life (t(1/2λ2) 7.55 ± 9.86 h), whereas ketamine was characterized by shorter half-life (t(1/2λ2) 4 ± 3.4 h) owing to its rapid biotransformation into norketamine. The clinical significance of propofol's long elimination half-life and low clearance is negligible when the drug is administered as short-term and low-dosage infusion. The concurrent administration of ketamine and propofol in cats did not produce adverse effects although it was not possible to exclude interference in the metabolism.

Data integration and systems biology approaches for biomarker discovery: challenges and opportunities for multiple sclerosis

New "omic" technologies and their application to systems biology approaches offer new opportunities for biomarker discovery in complex disorders, including multiple sclerosis (MS). Recent studies using massive genotyping, DNA arrays, antibody arrays, proteomics, glycomics, and metabolomics from different tissues (blood, cerebrospinal fluid, brain) have identified many molecules associated with MS, defining both susceptibility and functional targets (e.g., biomarkers). Such discoveries involve many different levels in the complex organizational hierarchy of humans (DNA, RNA, protein, etc.), and integrating these datasets into a coherent model with regard to MS pathogenesis would be a significant step forward. Given the dynamic and heterogeneous nature of MS, validating biomarkers is mandatory. To develop accurate markers of disease prognosis or therapeutic response that are clinically useful, combining molecular, clinical, and imaging data is necessary. Such an integrative approach would pave the way towards better patient care and more effective clinical trials that test new therapies, thus bringing the paradigm of personalized medicine in MS one step closer.