Importance of CYP2C19 genetic polymorphism in the eradication of Helicobacter pylori in north Indians.

Background & objectives: Genetic polymorphism of CYP2C19 is known to occur with a frequency of 12 per cent in north Indian population. But no study correlated CYP2C19 genetic polymorphism with eradication of Helicobacter pylori in north Indian gastritis patients positive for H. pylori and hence this study. Methods: Ninety one consecutive patients positive for H. pylori fulfilling the study criteria were phenotyped and genotyped for CYP2C19. They were given 20 mg omeprazole (OPZ), 750 mg amoxicillin (AMC) and 500 mg tinidazole (TNZ) (bid) for 7 days followed by 20 mg OPZ (qd) for 21 days. Non eradicated extensive metabolizers (EMs) were retreated with 40 mg OPZ (bid) and 500 mg AMC (qid) for 14 days. Results: EMs and poor metabolizers (PMs) excreted 4.26 ± 0.34 (95% CI 3.59-4.92) and 0.73 ± 0.05 (95% CI 0.63-0.82) μmol 5-OH-OPZ in 8 h, respectively. After initial therapy, EMs demonstrated 37 per cent (95% CI: 24.5-49.5) and PMs 92 per cent (95% CI: 77-107) eradication of H. pylori. Non eradicated EMs after retreatment demonstrated 90 per cent (95% CI: 79-101) eradication. Interpretation & conclusions: This study demonstrated a direct correlation between CYP2C19 genetic polymorphism and H. pylori eradication in north Indian patients with gastritis. Knowing the CYP2C19 phenotype of a patient may help in prescribing optimum dose of proton pump inhibitor to achieve better therapeutic outcome.

Distribution of malignant neoplasms reported at different pathology centers and hospitals in Jaipur, Rajasthan.

Background: Cancer data from Rajasthan are limited. Only two studies, one from Western Rajasthan, and the other from Eastern Rajasthan have been published by Sharma et al. in 1992 and 1996. Aims: To put the cancer profile from this region in proper perspective, we conducted the present study on the patterns of various malignancies in Jaipur region, i.e., Eastern Rajasthan. Setting and Design and Material and Methods: The study spans over one and half decade (1990-2004) and is based on a retrospective six-year sample analysis of approximately 200,000 histopathological and cytological reports for the years 1990, 1991, 1996, 1999, 2001 and 2004. Results: A total of 21,868 cancers were recorded in the six sample years. There were 59.11% (12,926) males and 40.89% (8942) females, with the male to female ratio being 1.45:1. Organ wise, lung (8.45%), prostate (7.12%), brain (6.04%), urinary bladder (5.31%), esophagus (4.67%) and tongue (4.60%) are most common sites involved in males with regard to frequency, whereas breast (20.44%), cervix (14.99%), ovary (4.35%), brain (3.80%), esophagus (3.67%), uterus (3.01%) and rectum (2.80%) are common sites for malignancies in females. Conclusions: Significant findings were a higher frequency of cancers of the prostate, urinary bladder, and brain in males along with gall bladder cancers in females. Our figures have been compared with the national data.

Genetic polymorphism of CYP2C19 & therapeutic response to proton pump inhibitors.

Proton pump inhibitors (PPIs) are extensively metabolized in the liver by CYP2C19, that demonstrates genetic polymorphism with 21 mutant alleles. The subjects can be divided into 2 groups with respect to CYP2C19 phenotypes viz., extensive metabolizers (EMs) and poor metabolizers (PMs) of PPIs. This division results in marked interindividual variations in the pharmacokinetics and pharmacodynamics of PPIs in the population. Intragastric pH values and the plasma concentration of PPIs after oral ingestion were significantly lower in EMs namely normal homozygotes (CYP2C19*1/*1) and heterozygotes (CYP2C19*1/*X) compared to PMs namely mutant homozygotes (CYP2C19*X/*X) where 'X' represents the mutant allele. Hence, association has been found between the genetic polymorphism of CYP2C19 and therapeutic response to PPIs. CYP2C19 polymorphism affected eradication of Helicobacter pylori using diferent PPI based eradication therapies as PM patients demonstrated significantly higher eradication rates compared to EMs. CYP2C19 genetic polymorphism also affects the therapeutic outcome of gastroesophageal reflux disease (GERD), reflux oesophagitis and duodenal ulcers. For optimal therapeutic response with PPIs, CYP2C19 pharmacogenetics should be taken into consideration. This shall help in the prescription of optimal doses of PPIs, thus paving the way for personalized medication.

A reverse phase high performance liquid chromatography method for simultaneous estimation of melatonin, carbamazepine epoxide and carbamazepine simultaneously in serum.

Monitoring of plasma antiepileptic drugs is useful for better clinical management in epileptic patients, particularly in children. Carbamazepine (CBZ) is one of the commonly prescribed anticonvulsants. The active metabolite of carbamazepine-carbamazepine-10-11 epoxide (CBZ-Epo) also exhibits anticonvulsant effect. The pineal hormone, melatonin exerts an anticonvulsant effect in experimental seizure models and recently has also been used in cases of childhood epilepsy. To facilitate the simultaneous plasma estimation of carbamazepine, carbamazepine epoxide, and melatonin, a new HPLC method was developed. Waters millennium 2010 chromatography manager with a 515 HPLC pump and Waters 24879 dual absorbance UV detector was used. A 25 microlitre of sample and standards were injected, and chromatographic separation was achieved by Merck C18 reverse phase column particle size 5 micro, 250 mm x 4 mm. It was quantitated at UV light 210 nm. The retention times of melatonin, CBZ-Epo, and CBZ were 6.3 min, 7.5 min, and 13.9 min respectively. The Mobile Phase used was water: acetonitrile (70:30), pH 3.0 adjusted with orthophosphoric acid at the flow rate of 1 ml/min. The limits of detection of melatonin, carbamazepine epoxide, and carbamazepine were 800, 500, and 1300 pg respectively.

Drug Utilization Study in Outpatient Ophthalmology Department of Government Medical College Jammu

The present study was undertaken to assess the patterns of prescription and drug utilization by measuring WHO delineated drug use indicators. This study was conducted in the Postgraduate Department of Pharmacology and Therapeutics in collaboration with the Postgraduate Department of Ophthalmology Govt. Medical College Hospital, Jammu. Total number of prescriptions analyzed were 440 , in which total of 822 drugs were prescribed. Analysis of the prescriptions showed that average number of drugs per prescription was 1.87. The maximum number of drugs prescribed were in the form of eye drops (66.18%), followed by ointments (16%), capsules (9.5%), tablet (6.57%), syrup (0.73%), injection (0.73%) and lotion (0.24%). The dosage form was indicated for 94%, frequency of drug administration for 98% drugs and duration of treatment for only 75% of the drugs prescribed. The number of antibiotics prescribed was 266 (32.26%), out of these 160 (60.15%) antibiotics prescribed in the form of drops, 100 (37.59%) as ointment and 6 (2.26%) orally. Number of encounters with anti-inflammatory and antiallergic drugs was 92 (11.2%), mydriatics and cycloplegics 64(7.9%), miotics 20 (2.4%), multivitamins 58 (7.05%) andothers used were lubricant and miscellaneous eye drops 322 (40%). Common prescription writing errors were minimum and there was no evidence of polypharmacy. However, duration of treatment and prescribing by generic name was very low.

Glaucoma Therapy: Prescribing Pattern and Cost Analysis

In the present study out of total 200 prescriptions of POAG (primary open angle glaucoma) studied 66% were found to be of monotherapy including timolol, brimonidine, pilocarpine, betaxolol, levobunolol, latanoprost and apraclonidine in 30%, 15 %, 6%, 8% , 4%, 1% and 2% of the prescriptions respectively and 34% were found to be of polypharmacy with timolol+pilocarpine, timolol+acetazolamide, timolol+ brimonidine and betaxolol+brimonidine in 13%, 4%, 8% and 9% of the prescriptions respectively. 10% drugs were prescribed by generic name. Written instruction to the patients regarding dose and dosing interval was mentioned in 100% prescriptions, but the proper method of instillation was mentioned only in 15% of the prescriptions. Results of the present study clearly indicated urgent need for prescribers to improve their communication skills, to give proper instructions to the patient regarding instillation of drug, as little bit of caution like instillation from the side of the eye in the supine position followed by rolling of the eyeball can decrease the wastage, decrease cost and improve compliance. However, in the present scenario cost of the traditional medications like betablockers, pilocarpine etc. is found to be much less than newer medications (prostaglandin analogues, brimonidine). Moreover, in presence of wide cost variation among various brands of the same drug our study could help the opthalmologist to use all possible measures of pharmacoeconomics while prescribing an antiglaucoma drug.

Current drug therapy of protozoal diarrhoea.

Protozoal infections of the gastrointestinal tract occur worldwide and have substantial morbidity and mortality. Prevalence is higher in the economically deprived regions of the world, especially the developing countries. Infections like amoebiasis and giardiasis have a worldwide distribution, being endemic in India. Apart from producing GI symptoms, growth and development of children is also impaired. It is seen that protozoa multiply rapidly in their hosts and as there is a lack of effective vaccines, chemotherapy has been the only practiced way to treat individuals and reduce transmission. The current treatment modalities for protozoal diarrhoea include 5-nitrosoimidazoles, iodoquinol, diloxanide furoate, paromomycin, chloroquine, and trimethoprim-sulphamethoxazole.

Neuroprotective role of melatonin in oxidative stress vulnerable brain.

The brain is deficient in oxidative defense mechanisms and hence is at greater risk of damage mediated by reactive oxygen species (ROS) resulting in molecular and cellular dysfunction. Emerging evidence suggesting the activation of glutamate gated cation channels, may be another source of oxidative stress, leading to neuronal degeneration. Oxidative stress has been implicated in the development of neurodegenerative diseases like Parkinsonism, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, epileptic seizures, and stroke. Melatonin, the pineal hormone, acts as a direct free radical scavenger and indirect antioxidant. It is suggested that the increase in neurodegenerative diseases is attributable to a decrease in the levels of melatonin with age. Melatonin has been shown to either stimulate gene expression for the antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase) or to increase their activity. Additionally, it neutralizes hydoxyl radical, superoxide radical, peroxyl radical, peroxynitrite anion, singlet oxygen, hydrogen peroxide, nitric oxide, and hypochlorous acid. Unlike other antioxidants, melatonin can easily cross all morphophysiological barriers, e.g., the blood brain barrier, and enters cells and subcellular compartments. Though evidence are accumulating to suggest the potential of melatonin in neurodegenerative conditions, much information needs to be generated before the drug can find place in neurology clinics.

Effect of low voltage on electrical properties of eye lens.

In the present study, the Cole-cole plot of lens tissue has been drawn using AC impedance system (EG and G PARC Model 318) in the frequency range 10 mHz to 10 Hz at low voltage stress. The impedus locus between real part (Z') and imaginary part (Z") of complex impedance of lens was examined. Results showed that the extracellular resistance (Re), distribution factor (alpha) and depressed angle (theta) were significantly varied at experimental low voltages. An attempt has been made to explain the electrical data of voltage-tissue interaction on the basis of solid state biophysics.

Purification of catalytically active hepatic NADPH cytochrome P450 oxidoreductase from the rhesus monkey, Macaca mulatta.

Hepatic NADPH cytochrome P450 oxidoreductase capable of supporting polysubstrate monooxygenase (PSMO) reactions was purified from microsomes obtained from phenobarbitone (PB) pretreated rhesus monkey. Two preparations of the enzyme purified by affinity and molecular exclusion chromatographic techniques demonstrated specific content of 19.5 and 37.9 nmol cytochrome c reduced/min/mg protein and subunit molecular weight of 66 and 80 kDa, respectively. Both forms supported oxidation of NADPH and reduction of cytochrome c and DCIP but only 80 kDa preparation supported PSMO reactions. The reconstituted system consisted of hepatic P450, NADPH cytochrome P450 oxidoreductase, cytochrome b5 all purified from PB pretreated rhesus monkey and dilauroyl phosphatidylcholine or microsomal lipid. Eighty kDa preparation supported the metabolism of aminopyrine and tolbutamide by hepatic P4502C and erythromycin, ethylmorphine and nifedipine by hepatic P450 3A, respectively. The turnover of these substrates increased in the presence of partially purified cytochrome b5 from the rhesus monkey. To best of our knowledge this is the first report on the purification of monkey hepatic NADPH cytochrome P450 oxidoreductase capable of supporting in vitro PSMO by different isozymes of P450.

Gene regulation of cytochrome P450--an overview.

Xenobiotics have played a role in elucidating the regulation of gene expression of hepatic cytochrome P450 in the eukaryotes. The major regulation of P450 genes in the eukaryotes is at the transcriptional and post transcriptional level. Polycyclic aromatic hydrocarbons regulate the gene expression by binding the cytosolic aryl hydrocarbon receptor and its translocation to the nucleus where it forms a ternary complex with aryl hydrocarbon nuclear translocator. The ternary complex PAH-AHR-ARNT acts as a transcription factor and binds aromatic hydrocarbon responsive element to increase the expression of CYP1A1 gene. Phenobarbitone and ethanol regulate the expression of respective P450s within CYP2 gene family by different mechanisms but without the involvement of a cytosolic receptor. PB uses phosphorylation as a switch to increase the affinity of the transcription factor(s) for the positive rather than negative PB regulatory element within CYP2B1/2. This is one of the novel ways that nature has designed for a protein to act as a negative as well as a positive acting transcription factor. Ethanol regulates the expression of CYP2E1 by posttranslational stabilization making it resistant to the proteolytic digestion. Steroids regulate expression of CYP3A genes through a receptor mediated mechanism. The binary complex of the steroid and its receptor increases the transcription of CYP3 genes by binding glucocorticoid responsive element which is already occupied by another protein. Peroxisome proliferators also follow a receptor mediated mechanism in which a binary complex of PP activated receptor and retinoid X receptor acts a transcription factor and increases the expression of CYP4A genes by binding peroxisome proliferator responsive element. These studies demonstrate that PAH, glucocorticoids and PP follow a receptor mediated whereas PB and ethanol follow a nonreceptor mediated mechanism for the regulation of respective P450 genes in the eukaryotes.

Near ultraviolet radiation induced changes in goat lens.

The possibility that the ultraviolet radiation from sunlight and other ambient sources as a major causative factor for the onset of cataract processes and photolytic changes of the eye lens constituents was studied. Normal goat lenses exposed in vitro to near UV radiation in the region of 315-400 nm (UV-A) revealed distinct morphological changes in the ultrastructure, increase in the inorganic elements; C, H, N, and a sharp shift in the intrinsic fluorescence spectra. UV exposure resulted in an alteration in the lambda max of the excitation spectra, a red shift in the emission absorption maxima and also an increase in the absolute fluorescence intensity. Scanning electron microscopic study showed a significant increase in the interfibrillar distances of the lens structural proteins. It is argued that the UV light induced covalent modifications of the lens proteins and their aggregations might have occurred due to the generation of photolytic products which then lead to oxidative damages.

Perioperative myocardial infarction in coronary artery disease patients and 'at-risk' for coronary artery disease patients undergoing non-cardiac surgery.

BACKGROUND: Perioperative myocardial infarction (POMI) carries a high mortality and occurs more commonly in patients with a history of coronary artery disease (CAD). However, there are also other patients undergoing surgery who are 'at risk' for CAD but who do not have a history of infarction or angina. We compared the incidence of POMI in these two groups. METHODS: In a prospective study of 69 men and 39 women over 30 years of age undergoing non-cardiac surgery under general or regional anaesthesia, 56 had definite CAD and 52 were 'at-risk' for CAD. All these patients were followed up with serial postoperative electrocardiography and CK-MB isoenzyme analysis for the diagnosis of POMI. RESULTS: The POMI rate was 32% in definite CAD patients and 15% in patients 'at-risk' for CAD. Mortality in patients with POMI was 17% in those with CAD and 13% in those 'at-risk' for CAD. Perioperative myocardial infarction was maximal in the first 24 hours following surgery (77%). All the POMIs were painless. Anaesthesia techniques--whether regional or general--did not influence the incidence of POMI (Chi-square, p > 0.05). The type of drugs used in the treatment of CAD such as beta-blockers, calcium channel blockers and antiplatelet agents did not cause any difference in the incidence of POMI (Chi-square, p > 0.05). Patients who had either an intraoperative hypertensive episode, tachycardia, arrhythmias or ST-segment changes had a higher incidence of POMI (Chi-square, p > 0.05). The incidence of POMI was not lower in patients undergoing transurethral resection of the prostate compared to patients undergoing other types of non-cardiac surgery (Chi-square, p > 0.05). CONCLUSION: POMI occurs in one-third of patients with a history of CAD and one-sixth of those 'at-risk'. It carries a mortality of 17% and 13% respectively. Decisions to operate on such patients should be taken with caution.

Rational drug therapy as evaluated from student's clinical case reports.

210 prescriptions selected by students from Sucheta Kriplani and R.M.L. Hospitals were subjected to audit prescription in a group discussion with faculty members in the Department of Pharmacology of Lady Hardinge Medical College, New Delhi. It was observed that inadequate treatment was prescribed to the patients suffering from common diseases like amoebiasis, tuberculosis and typhoid fever. Indiscriminate use of antibiotics, antihistaminics, NSAID, vitamins and haematinics was a common observation.