Ajay Sharma - Academia.edu (original) (raw)

Papers by Ajay Sharma

Pharmacological Research, 2000

The present study is designed to investigate the mechanism of the cardioprotective effect of isch... more The present study is designed to investigate the mechanism of the cardioprotective effect of ischaemic preconditioning. Isolated perfused rat heart was subjected to global ischaemia for 30 min followed by reperfusion for 120 min. Coronary effluent was analysed for LDH and CK release to assess the degree of cardiac injury. Myocardial infarct size was estimated macroscopically using TTC staining. Four episodes of ischaemic preconditioning markedly reduced LDH and CK release in the coronary effluent and decreased myocardial infarct Ž . size. Administration of prazosin ␣ adrenoceptor antagonist before global ischaemia 1 reduced the extent of ischaemia-reperfusion induced myocardial injury. The cardioprotec-Ž tive effect of ischaemic preconditioning was abolished by prazosin and colchicine micro-. tubule disaggregator . On the basis of these results, it may be concluded that the cardioprotective effects of ischaemic preconditioning may be mediated through stimulation of ␣ 1 adrenoceptors and translocation of PKC.

Planta Medica, 2010

Tissue culture technique is becoming popular because of its well-known ability to enhance the con... more Tissue culture technique is becoming popular because of its well-known ability to enhance the content of secondary metabolites in plants. Callus tissue cultures of Nothapodytes foetida were developed using 250 different medium compositions to optimize this procedure. Methanolic extracts of callus (MEC) and of various parts of N. foetida were comparatively analyzed for camptothecin content, and a high performance thin layer chromatography method was developed for its quantitation. Chloroform-ethylacetate-methanol (4 : 5 : 0.5 v/v) was used as the mobile phase. The method was validated for linearity, precision (interday and intraday), repeatability, limit of detection (LOD), limit of quantitation (LOQ), and accuracy. The relationship between the concentration of standard solutions and the peak response was linear within the range of 80 to 480 ng/spot with a correlation coefficient of 0.998 +/- 0.020. Instrumental precision was evaluated as 0.54 (% CV). Repeatability of sample and standard were estimated to be 1.08 and 1.01 (% CV), and LOD and LOQ were found to be 40 and 80 ng/spot, respectively. The accuracy of the method was checked out by a recovery study and the average percentage recovery was calculated as being 99.13 %. The methanolic extract of callus grown in tissue culture with medium composition picloram + thidiazuron + gibberellic acid (1 : 1 : 4; MEC-PTG) showed a higher percentage of camptothecin (5.74 % w/v) than the methanolic extract of fruits (3.56 % w/w), leaves (1.56 % w/w), stem (1.19 % w/w), and root (1.11 % w/w). The results of the antimicrobial screening indicate that MEC-PTG exhibited maximum activity against all microorganisms. Among the fungi tested, MEC-PTG showed maximum activity against A. niger and C. albicans (MIC value 10 microg/mL) whereas among bacteria strains, its activity was highest against B. subtilis and S. lutea (MIC 20 microg/mL).

Pharmacology, 1998

Alprazolam produced anterograde as well as retrograde amnesia in mice assessed using elevated plu... more Alprazolam produced anterograde as well as retrograde amnesia in mice assessed using elevated plus-maze. Flumazenil (10 mg/kg i.p.) attenuated anterograde and retrograde amnesia produced by alprazolam. It is proposed that anterograde amnesia produced by alprazolam may be mediated through the activation of benzodiazepine receptors. Retrograde amnesia of alprazolam may be mediated through the blockade of PAF receptors. Moreover, flumazenil facilitates learning and memory perhaps by modulating the release of PAF and consequently attenuated alprazolam and BN-50730-(PAF receptor antagonist)-induced retrograde amnesia.

Mini-Reviews in Medicinal Chemistry, 2013

In the last few decades, a lot of work has been done on heterocycles, especially the imidazole ri... more In the last few decades, a lot of work has been done on heterocycles, especially the imidazole ring, to obtain a scaffold with potential pharmacological properties such as antibacterial, antifungal, anticancer, antiviral, antidiabetic and others, with lesser side effects. The search for new biologically active imidazoles continues to be an interesting area of investigation in medicinal chemistry. The present paper aims to bring together and discuss the wealth of information on antibacterial profile of imidazoles. So it can be employed for future development to obtain new potent drug molecules.

Journal of Cardiovascular Pharmacology, 1999

This study was designed to investigate the role of angiotensin (Ang II) in the cardioprotective e... more This study was designed to investigate the role of angiotensin (Ang II) in the cardioprotective effect of ischemic preconditioning. Isolated perfused rat heart was subjected to global ischemia for 30 min followed by reperfusion for 120 min. Coronary effluent was analyzed for lactate dehydrogenase (LDH) and creatine kinase (CK) release to assess the degree of cardiac injury. Myocardial infarct size was estimated macroscopically by using triphenyl tetrazolium chloride (TTC) staining. Four episodes of ischemic/Ang II preconditioning markedly reduced LDH and CK release in the coronary effluent and decreased myocardial infarct size. The cardioprotective effect of Ang II preconditioning was abolished by CV 11974, AT1-receptor antagonist, whereas no such effect was noted with CV 11974 in ischemic preconditioning. PD 123319, AT2-receptor antagonist, produced no marked effect on Ang II preconditioning and ischemic preconditioning induced reduction in myocardial injury. On the basis of these results, it may be concluded that activation of AT1 receptors may be involved in angiotensin-induced pharmacologic preconditioning. But it may not be involved in the cardioprotective effect of ischemic preconditioning in isolated rat heart.

Clinical and Experimental Pharmacology and Physiology, 2012

1. One of the major causes of metabolic syndrome is elevated 11b-hydroxysteroid dehydrogenase 1 (... more 1. One of the major causes of metabolic syndrome is elevated 11b-hydroxysteroid dehydrogenase 1 (11b-HSD1) in the liver and adipose tissue. High 11b-HSD1 expression contributes significantly to the diabetic phenotype in db ⁄ db mice. The purpose of the present study was to test the effect of the pharmacological inhibition of 11b-HSD1 inhibition by carbenoxolone in db ⁄ db mice, a genetic model of diabetes.

Pediatric Transplantation, 2009

Kidney International, 2011

Journal of Glaucoma, 2010

To study the long-term course of primary angle closure (PAC) eyes after iridotomy. Seventy-two ey... more To study the long-term course of primary angle closure (PAC) eyes after iridotomy. Seventy-two eyes of 72 patients diagnosed as PAC, having occludable angles with evidence of closure, but no ocular hypertension, were studied. Laser iridotomy was carried out in all eyes at baseline. Standard achromatic perimetry and tonometry were recorded at baseline and serially every 6 months, for at least 4 years. Changes on perimetry and the intraocular pressure (IOP) were analyzed. At 1 year, 10 eyes and at final review, 26 eyes had developed ocular hypertension and required topical antiglaucoma medication. Eight eyes developed visual field defects on standard achromatic perimetry, over a mean period of 6.89±2.4 years. Eyes that progressed on perimetry, had a significantly narrower angle recess, less than or equal to 10 degrees, P=0.04, and a higher baseline MD and PSD, P=0.004 and 0.03, respectively. They also showed having a larger intervisit IOP fluctuation of 8.9±2.3 mm Hg, cf stable eyes, 6.2±3 mm Hg, P=0.003, and a longer duration of follow-up, P=0.01. A third of PAC eyes, with very narrow angles, higher global indices, intervisit IOP fluctuations, and a longer duration of follow-up were observed to develop ocular hypertension. A third of the PAC eyes with hypertension, that is 11.1% overall, went on to develop PAC glaucoma.

$Research paper thumbnail of Diastatic fracture of the skull with pseudomeningocele in childhood$

Clinical Neurology and Neurosurgery, 1997

A decade ago,we seta database on traumapatients. Interimanalysis disclosed muchbetteroutcome of c... more A decade ago,we seta database on traumapatients. Interimanalysis disclosed muchbetteroutcome of children with severehead injury.