Novel applications of nanotechnology in medicine.

Current modalities of diagnosis and treatment of various diseases, especially cancer have major limitations such as poor sensitivity or specificity and drug toxicities respectively. Newer and improved methods of cancer detection based on nanoparticles are being developed. They are used as contrast agents, fluorescent materials, molecular research tools and drugs with targeting antibodies. Paramagnetic nanoparticles, quantum dots, nanoshells and nanosomes are few of the nanoparticles used for diagnostic purposes. Drugs with high toxic potential like cancer chemotherapeutic drugs can be given with a better safety profile with the utility of nanotechnology. These can be made to act specifically at the target tissue by active as well as passive means. Other modalities of therapy such as heat induced ablation of cancer cells by nanoshells and gene therapy are also being developed. This review discusses the various platforms of nanotechnology being used in different aspects of medicine like diagnostics and therapeutics. The potential toxicities of the nanoparticles are also described in addition to hypothetical designs such as respirocytes and microbivores. The safety of nanomedicine is not yet fully defined. However, it is possible that nanomedicine in future would play a crucial role in the treatment of human diseases and also in enhancement of normal human physiology.

Influence of the CYP2C9 AND CYP2C19 polymorphisms on phenytoin hydroxylation in healthy individuals from south India.

BACKGROUND AND OBJECTIVES: Phenytoin, a widely used anti-epileptic drug, is metabolized mainly by CYP2C9 (90%) and partly by CYP2C19 (10%) to its major metabolite 5-(para-hydroxyphenyl)-5- phenylhydantoin (p-HPPH). The CYP2C9 and CYP2C19 genes encoding these enzymes are polymorphically expressed and most of the variants result in decreased metabolism of the respective substrates. The present study was undertaken to investigate the influence of the CYP2C9*2 and *3 as well as CYP2C19*2 and *3 variant genotypes on phenytoin hydroxylation in healthy subjects from south India. METHODS: A total of 27 healthy, unrelated, subjects were administered a single oral dose of 300 mg phenytoin. Four hours later, 5 ml of blood was collected and genotyped for CYP2C9*1, *2, *3, CYP2C19*1, *2 and *3 by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Phenytoin and the major metabolite p-HPPH were estimated by reverse phase HPLC. The metabolic ratio was calculated as concentration of phenytoin/p-HPPH. RESULTS: A significant correlation was observed between the CYP2C9 genotype and metabolic ratio of phenytoin/p-HPPH (r = 0.472, 95% CI 0.100 to 0.728; P = 0.01). While no association was found with CYP2C19 alone, a significant correlation was observed between the combined CYP2C9 and CYP2C19 genotypes and phenytoin metabolic ratio (r = 0.507, 95% CI 0.146 to 0.749; P< 0.01). INTERPRETATION AND CONCLUSION: CYP2C9*2 and *3 mutant alleles caused decreased hydroxylation of phenytoin in vivo, whereas the mutant alleles of CYP2C19 played only a minor role in the metabolism of phenytoin in subjects of our study. The results of present preliminary study needs to be confirmed with a larger sample.

Effect of slow and fast pranayams on reaction time and cardiorespiratory variables.

We planned to undertake a comparative study of the effect of short term (three weeks) training in savitri (slow breathing) and bhastrika (fast breathing) pranayams on respiratory pressures and endurance, reaction time, blood pressure, heart rate, rate-pressure product and double product. Thirty student volunteers were divided into two groups of fifteen each. Group I was given training in savitri pranayam that involves slow, rhythmic, and deep breathing. Group II was given training in bhastrika pranayam, which is bellows-type rapid and deep breathing. Parameters were measured before and after three week training period. Savitri pranayam produced a significant increase in respiratory pressures and respiratory endurance. In both the groups, there was an appreciable but statistically insignificant shortening of reaction time. Heart rate, rate-pressure product and double product decreased in savitri pranayam group but increased significantly in bhastrika group. It is concluded that different types of pranayams produce different physiological responses in normal young volunteers.