Browsing by Author "Gupta, Y K"
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Item Abuse liability of diazepam through different routes.(2001-04-02) Singh, R K; Jain, R; Ray, R; Gupta, Y KAbuse liability of diazepam was examined among experienced drug users. The subjects, randomly divided into two groups, each having eight subjects, received diazepam, 15 mg intravenously (gr. 1) and 30 mg orally (gr. 2). Subjective states, drug liking, sedation and euphoria were assessed at pre-drug, 15 min, 120 min and 240 min post-drug administration. In addition, brief assessment to evaluate euphoria and sedation was carried out at 5 min and 45 min for subjects in gr. 1, and at 45 min and 150 min for those in gr. 2. Plasma diazepam level was also estimated. Results indicate those subjects in gr. 1 reported quicker and higher euphoria, drug liking, subjective effects and higher plasma level. The study suggests that route of administration of a compound which has faster onset of action is associated with more liability of abuse.Item Adenosinergic system as an endogenous anticonvulsant mechanism.(1997-10-11) Gupta, Y K; Malhotra, JThe treatment of epilepsies remains far from adequate primarily due to inadequate understanding of the pathophysiology of seizures. The conventional approach for research into epilepsy has been study of factors responsible for initiation of seizures. However, now attention is being drawn to the spontaneous and abrupt arrest of seizures which suggests a distinct possibility of activation of an endogenous anticonvulsant mechanism(s), which may be targeted in future for controlling seizures. Of the various endogenous anticonvulsant mechanisms, the concept of an endogenous anticonvulsant substance has gained much experimental support and, many potential candidates have been postulated. Of these adenosinergic system appears to be the most promising. This review discusses the possible role of adenosinergic system in seizures, in relation to the available antiepileptic drugs and its therapeutic implications.Item Animal models of cerebral ischemia for evaluation of drugs.(2004-10-24) Gupta, Y K; Briyal, SeemaStroke is a major cause of death and disability worldwide. The resulting burden on the society continues to grow, with increase in the incidence of stroke. Brain attack is a term introduced to describe the acute presentation of stroke, which emphasizes the need for urgent action to remedy the situation. Though a large number of therapeutic agents like thrombolytics, NMDA receptor antagonists, calcium channel blockers and antioxidants, have been used or being evaluated, there remains a large gap between the benefits by these agents and properties an ideal drug for stroke should offer. In recent years much attention is being paid towards the exploration of herbal preparation, antioxidant agents and combination therapies including COX-2 inhibitors in experimental model of stroke. For better evaluation of the drugs and enhancement of their predictability from animal experimentation to clinical settings, it has been realized that the selection of animal models, the parameters to be evaluated should be critically assessed. Focal and global cerebral ischemia represents diseases that are common in the human population. Understanding the mechanisms of injury and neuroprotection in these diseases is important to learn new target sites to treat ischemia. There are many animal models available to investigate injury mechanisms and neuroprotective strategies. In this article we attempted to summarize commonly explored animal models of focal and global cerebral ischemia and evaluate their advantages and limitations.Item Anti-inflammatory activity of sodium pyruvate--a physiological antioxidant.(2000-01-05) Gupta, S K; Rastogi, S; Prakash, J; Joshi, S; Gupta, Y K; Awor, L; Verma, S DThe anti-inflammatory activity of sodium pyruvate was evaluated in acute and chronic models of inflammation in rats. Oral administration of sodium pyruvate at three different dose levels of 125, 250 and 500 mg/kg body weight significantly inhibited the carrageenan induced acute paw edema in a dose dependent manner. The effect of 500 mg/kg sodium pyruvate was comparable to that of 12.5 mg/kg of standard diclofence. In Freund's adjuvant arthritis model, oral administration of sodium pyruvate at the submaximal dose of 250 mg/kg once daily upto one week before Freund's adjuvant injection and immediately by the same route on the 7th day of adjuvant injection significantly reduced the edema at 18 hours after the challenge. The treatment was continued for 14 days thereafter in two divided doses of 125 mg/kg in the morning and 125 mg/kg in the evening. Sodium pyruvate showed significant anti-inflammatory activity at the 14th day (chronic phase) also. To conclude, sodium pyruvate exhibited significant anti-inflammatory activity in both the models of inflammation which could be attributed to its antioxidant properties.Item Antiarthritic activity of Majoon Suranjan (a polyherbal Unani formulation) in rat.(2011-09) Singh, Surender; Nair, Vinod; Gupta, Y KBackground & objectives: Majoon Suranjan (MS) is a polyherbal formulation used in Unani system of medicine for the treatment of rheumatoid arthritis (RA). The present study evaluates the antiarthritic efficacy of this formulation in three different experimental models. Methods: The anti-inflammatory activity of MS (in doses of 450, 900 and 1800 mg/kg body wt) was evaluated using the turpentine oil induced paw oedema model and the antiarthritic efficacy was evaluated using the formaldehyde and complete Freund's adjuvant (CFA) induced arthritis models. Aspirin (100 mg/kg body wt) was used as the standard drug in all the models. In order to assess the safety of the test drug, oral acute and 28 day toxicity studies were also carried out. Results: MS produced a dose dependent protective effect in all the experimental models. Its antiarthritic efficacy was comparable to aspirin in formaldehyde induced arthritis and was superior to aspirin in turpentine oil induced paw oedema and CFA induced arthritis. MS also inhibited the delayed increase in joint diameter as seen in control and aspirin treated animals in CFA induced arthritis. Oral LD50 of MS was found to be >5000 mg/kg in rats. Chronic administration did not produce any significant physiological changes in the tested animals. Interpretation & conclusions: Results of the present study suggest that the antiarthritic activity of MS was due to the interplay between its anti-inflammatory and disease modifying activities, thus supporting its use in traditional medicine for the treatment of RA.Item Antiepileptic activity of Panax ginseng against pentylenetetrazole induced kindling in rats.(2001-10-09) Gupta, Y K; Sharma, M; Chaudhary, GIn the present study, Panax ginseng was evaluated for its antiepileptic activity against pentylenetetrazole (PTZ) induced chemical kindling in rats. PTZ was injected at the dose of 30 mg/kg, i.p. on alternate days and the occurrence of generalized tonic clonic convulsions were considered as the end point. One group received Panax ginseng every day, at a dose of 100 mg/kg, 30 min prior to PTZ injection whereas the other group received an equal volume of distilled water to serve as control. In a separate group the rats were evaluated for motor performance tests after Panax ginseng. The rats treated with Panax ginseng showed significant protection as compared to vehicle treated PTZ injected rats. The study suggests to potential of Panax ginseng against seizures.Item Antiepileptic drug therapy in the twenty first century.(2000-01-05) Gupta, Y K; Malhotra, JIn the last 25 years, particularly the last decade, there have been many advances relating to all aspects of epilepsy i.e. pathophysiology, diagnosis, pharmacotherapy and surgical interventions. Noteworthy has been the progress in terms of understanding of the established antiepileptic drugs (AEDs) and introduction of several newer agents developed rationally, on the basis of now available information on the biochemical changes in the epileptic brain. Data is accumulating regarding the use of newer agents but they still need to stand the test of time. Many of the newer AEDs may offer a better tolerability because of favorable pharmacokinetic characteristics and minimal drug interactions. However, serious adverse events have been associated with felbamate and lamotrigine already and for other newer agents reliable and accurate data needs to be generated.Item Aspirin modulates the anticonvulsant effect of diazepam and sodium valproate in pentylenetetrazole and maximal electroshock induced seizures in mice.(2001-10-09) Srivastava, A K; Gupta, Y KRelease of prostaglandins in brain after spontaneous and experimentally induced seizures, has been demonstrated. The possible role of prostaglandins in modulation of seizure activity is still inconclusive. In the present study, the effects of aspirin and its interaction with the anticonvulsants (diazepam and sodium valproate) were studied in pentylenetetrazole (PTZ) and maximal electroshock (MES) induced seizures in mice. Aspirin 50, 100, and 500 mg/kg, i.p. was administered 45 min before the pentylenetetrazole (60 mg/kg, i.p.) and MES (60 mA, 0.2 s duration via car clip electrodes) challenge. In MES seizures significant protection was seen with aspirin 100 mg/kg where as higher dose of aspirin 500 mg/kg was required to elicit maximum protection against PTZ seizures. Sub anticonvulsant dose of sodium valproate 150 mg/kg, i.p. and aspirin 50 mg/kg i.p. showed complete protection in MES seizures and the same dose of sodium valproate offered superior protection in PTZ seizures than either drug used alone. When mice were pretreated with combination of diazepam 0.5 mg/kg and aspirin 50 mg/kg protection was significantly enhanced in PTZ seizures. However, aspirin did not show any significant protection with subanticonvulsant dose of diazepam against MES seizures. The present study suggests that prostaglandins may have anticonvulsant potential and also may have modulatory effect on anticonvulsant effect of conventional antiepileptic drugs.Item Calcium and calcium channel blockers: basic and clinical considerations.(1987-11-01) Seth, S D; Maulik, S K; Gupta, Y KItem Can large animal experiments be totally replaced by alternatives.(2008-07) Gupta, Madhur; Gupta, Y KItem Changes in circulatory biogenic amines during head-up tilt testing in neurocardiogenic syncope.(1996-11-01) Bhargava, B; Chandra, S; Kacker, V; Gupta, Y K; Kaul, U; Seth, S D; Wasir, H SThe pathogenesis of neurocardiogenic syncope is not completely understood. To examine the possible role of biogenic amines in patients with neurocardiogenic syncope, 18 consecutive patients (age 30 +/- 13 years, 15 males, 3 females) of unexplained syncope were subjected to Head-Up Tilt Testing (HUTT). Blood was sampled by an indwelling cannula at baseline, end of tilt test (or at syncope) and 1 min after returning to the supine position. Biogenic amines, epinephrine (E), norepinephrine (NE), serotonin (5-HT) and their metabolites, homovanillic acid (HVA) and 5-hydroxy indole acetic acid (5-HIAA), were measured in the serum after serial organic phase extraction by high-performance liquid chromatography (HPLC) using ultraviolet detection at a wavelength of 280 nm. Twelve patients were found to be HUTT negative while 6 patients were HUTT positive. Baseline E, NE and 5-HT levels were significantly greater in the HUTT positive patients [E 510 +/- 154 versus 302 +/- 96 pg/ml (p < 0.01), NE 253 +/- 99 versus 159 +/- 62 pg/ml (p < 0.05), 5-HT 174 +/- 32 versus 118 +/- 22 pg/ml (p < 0.01)]. E and HVA levels at the end of the test were significantly higher in HUTT positive patients [E 788 +/- 268 versus 465 +/- 119 pg/ml (p < 0.01), HVA 308 +/- 91 versus 112 +/- 12 pg/ml (p < 0.001)]. A significantly greater rise of E from the baseline was observed in HUTT positive patients (510 +/- 154 versus 112 +/- 12 pg/ml (p < 0.01)]. The increase in the levels of E and HVA both at baseline and after the tilt test, without a corresponding rise in NE levels indicates enhanced activity of the adrenomedullary axis which is not paralleled by NE release from sympathetic nerve endings in patients of neurocardiogenic syncope.Item Contribution of genomics and proteomics in understanding the role of modifying factors in Parkinson's disease.(2006-04-08) Singh, M P; Patel, S; Dikshit, M; Gupta, Y KParkinson's disease (PD) is a complex neurological disorder, characterized by selective degeneration of nigrostriatal dopaminergic neurons. It is a multi-factorial disease, contributed by a combination of age, genetic and environmental factors. Etiology of sporadic PD and mechanism underlying selective loss of dopaminergic neurons has not yet been clearly understood. Recent developments in genomics and proteomics have revolutionized the research on PD at genetic level. Differential gene expression patterns (DNA biochip technology), age-dependent complex genetic patterns (SNP genotyping), and protein expression profiles (proteomics) of PD patients have started providing the specific and rigorous molecular explanation and role of modifying factors in PD. Genomics and proteomics are further expected to help in developing biomarkers for diagnosis of early onset PD and also to develop valuable and potential therapeutic strategies for its treatment. In this review, we have discussed the progress made by genomics and proteomics, in understanding the role of modifying factors in PD.Item Contribution of genomics, proteomics, and single-nucleotide polymorphism in toxicology research and Indian scenario.(2005-05) Patel, S; Parmar, D; Gupta, Y K; Singh, M PAdvancement in the molecular tools used in toxicology has provided immense information about the cellular and global structure and function of toxicant-responsive genes. Now, it has become possible to assess the functional activity of genes and proteins involved in various toxicological pathways, which were not possible with the conventional methods. Many genes are known to have a greater influence on the susceptibility to environmental agents than others; therefore, identification and characterization of polymorphism in such genes for the determination of early, late, or no response of an individual for the toxicant-induced diseases has also become mandatory. Toxicogenomics, a newly born discipline of toxicology, comprises of two major facets, one, how various genes in the genome respond to environmental toxicants and stressors and second, how toxicants modify the function and expression of specific genes in the genome. Toxicogenomics play an important role in the identification and characterization of molecular biomarkers to predict cellular toxicity and to determine the efficacy and exposure in the toxicity trials at an early stage. Genome and proteome-wide expression profiles in combination with conventional toxicology are being used to classify compounds, predict the mechanism of toxicity of newer compounds and determine the susceptibility of an individual for the toxic responses. Single-nucleotide polymorphism in toxicant-responsive genes is being used to obtain basic information of the genetic variation and its role in the functional protein expression. Various national and international government and private organizations have launched several programs on gene-environment interactions. Council of Scientific and Industrial Research (CSIR), New Delhi, India, has also launched a program on 'toxicogenomics of genetic polymorphism in Indian population to industrial chemicals for development of biomarkers' to provide better ventures and facilities to researchers in order to understand the environment-genome interactions. In this review, the contribution of genomics, proteomics, and SNPs in toxicology along with its current status in India has been discussed3.Item Current drug therapy of protozoal diarrhoea.(2004-01-26) Gupta, Y K; Gupta, Madhur; Aneja, S; Kohli, KProtozoal 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.Item Delayed manifestation of ultra violet radiation induced erythema in guinea pigs by sodium pyruvate--a free radical scavenger.(1998-04-04) Gupta, S K; Awor, L; Rastogi, S; Prakash, J; Gupta, Y K; Varma, S D; Velpandian, TSodium pyruvate, a free radical scavenger was evaluated for anti-inflammatory activity using UV radiation induced dermal erythema on guinea pig and compared with that of standard naproxen. Oral as well as topical pyruvate exhibited significant activity against UV induced dermal erythema model and the activity was comparable to that of naproxen. In the other pharmacodynamic studies, such as the studies on rat blood pressure, isolated guinea pig ileum and rat uterus, it showed no effect on any of these. In conclusion, sodium pyruvate showed a significant protection in the UV induced dermal erythema in guinea pigs. It also showed good absorption in UV-B range and this property can be utilised to develop the sodium pyruvate as a sunscreening agent.Item Development of neurogenic pulmonary edema at different grades of intracranial pressure in cats.(1998-01-26) Gupta, Y K; Chugh, A; Kacker, V; Mehta, V S; Tandon, P NDevelopment of neurogenic pulmonary edema (NPE) subsequent to increased intracranial pressure (ICP) was evaluated in an experimental model in cats. Experiments were conducted in chloralose anaesthetised animals, either on spontaneous respiration or on intermittent positive pressure ventilation. Hemodynamic parameters i.e., mean arterial pressure (MAP) and heart rate (HR) were continuously monitored. Pulmonary artery/right ventricular systolic pressure was recorded in cats on spontaneous respiration. Increase in ICP for 180 minutes caused an increase in extravascular lung water (EVLW) content in both spontaneously breathing and artificially ventilated animals. In spontaneously breathing animals EVLW to blood free dry weight ratio (EVLW/BFDW) was 3.95 +/- 0.16 and 4.96 +/- 0.16 at ICP 40 and 80 mm Hg respectively while in animals on artificial ventilation, at 40, 60, 80 and 100 mm Hg ICP, it was 3.88 +/- 0.11, 4.09 +/- 0.10, 4.50 +/- 0.13 and 5.03 +/- 0.17 respectively. These values were significantly greater (P < 0.05) as compared to that in sham operated animals (3.43 +/- 0.10). This was accompanied by rise in MAP, HR and pulmonary artery pressure. The study establishes the graded development of NPE, the severity of which is proportional to the levels of ICP.Item Drug-eluting stents: a pharmacoclinical perspective.(2006-07-15) Thomas, Mathew K; Gupta, Y KIn the 26 years since Gruntzig introduced a simple balloon angioplasty technique, percutaneous coronary intervention has made extraordinary progress and has now surpassed bypass surgery in frequency. The area of coronary stenting has been the focus of intense research. One of the major problems encountered after stenting is an exaggerated vascular neointimal proliferation called in-stent stenosis. The evolution of drug-eluting stents has helped in reducing the incidence of in-stent stenosis by almost half. A number of pharmacological agents have been tried in coronary stents with varying degrees of success; many more are being developed and tested. Serious doubts have been expressed about the pharmacoeconomics of drug-eluting stents compared with bare metal stents, because of the huge disparity in costs. Drug-eluting stents, which can be grouped under both device and instrument, have thrown up interesting challenges for clinical trials. The future could see the development of more compact devices with the help of diverse fields such as nanotechnology, microelectronics and advanced materials technology.Item The effect of acute and chronic treatment of verapamil on pressor response to angiotensin II in rats.(1986-04-01) Lall, S B; Kheterpal, K; Rajdev, S; Gupta, Y KThe effect of verapamil on pressor response to Angiotensin II (A II) was investigated in rats. The responses to A II (10, 20, 40 ng, iv) was reduced after verapamil (50 and 100 micrograms, iv per rat) in a dose dependent manner. Treatment for 5 day with verapamil (18 mg/100 g/day, po) let to some reduction in basal blood pressure but pressor response to A II was not changed. Treatment for 20 days significantly reduced the basal blood pressure and increased the responsiveness to A II. it is concluded that Ca++ plays a major role in the pressor responses to A II and that chronic treatment with verapamil may reduce basal blood pressure.Item Effect of alpha lipoic acid, melatonin and trans resveratrol on intracerebroventricular streptozotocin induced spatial memory deficit in rats.(2005-10-04) Sharma, Monisha; Briyal, Seema; Gupta, Y KIn the present study, the effect of antioxidants-alpha lipoic acid, melatonin and trans resveratrol were studied against intracerebroventricular streptozotocin induced spatial memory deficit. Male Wistar rats were injected with intracerebroventricular streptozotocin bilaterally. The rats were treated chronically with alpha lipoic acid (200 mg/kg, po), melatonin (20 mg/kg, ip) and trans resveratrol (20 mg/kg, ip) for 18 days starting from day 1 of streptozotocin injection in separate groups. The spatial memory was evaluated using the Morris water maze task. The intracerebroventricular streptozotocin rats treated with antioxidants showed significantly less spatial memory deficit both in the acquisition and probe trials as compared to the vehicle treated rats. The study demonstrated the effectiveness of alpha lipoic acid, melatonin and trans resveratrol in preventing spatial memory deficit induced by intracerebroventricular streptozotocin and it's potential in age related neurodegenerative disorders where oxidative stress is involved such as Alzheimer's disease.Item Effect of Ca++ channel blockers and saralasin on angiotensin II induced contraction in rabbit aortic strip.(1986-04-01) Kheterpal, K; Lall, S B; Rajdev, S; Gupta, Y KTo investigate the role of calcium in angiotensin II (A II) induced contractions in rabbit aortic strip, the action of verapamil, nifedipine, cinnarizine and saralasin was studied. The cumulative dose response curves obtained with A II shifted to right with increasing concentrations of all these four agents. The antagonism was noncompetitive. The pD'2 value of saralasin was 8.49 of nifedipine, 8.15 and or verapamil 7.92. Cinnarizine which mainly acts at intracellular site had pD'2 value 5.54. The results indicate that A II induced contractions critically depend on entry of calcium through channels which appear to be closely associated with angiotensin receptors.
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