Biomedical subjects

Y K Gupta

Publications and source records attributed to Y K Gupta.

99 records · Page 6Linked to original sources

PubMedDate not supplied

Effect of alpha lipoic acid, melatonin and trans resveratrol on intracerebroventricular streptozotocin induced spatial memory deficit in rats.

In 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.

Animals↗

PubMedDate not supplied

Post traumatic epilepsy: a review of scientific evidence.

Post traumatic epilepsy is the development of recurrent seizures following head trauma and has a high clinical relevance. Several risk factors including some genetic factors increase the susceptibility of post traumatic epilepsy. The precise mechanisms of epileptogenesis in post-traumatic epilepsy are still poorly understood. Many structural, physiologic and biochemical changes in the brain may account for epileptogenesis. The reactive oxygen species (ROS), especially *OH and excitotoxicity are primarily involved. Antioxidants, like tocopherol, antiepileptic drug zonisamide, condensed tannins, melatonin, adenosine, trans-resveratrol, and some other agents have been proposed to prevent epileptogenic focus formation. The review also discusses various aspects of post traumatic epilepsy, mechanisms of epileptogenesis, and clinical implications.

Animals↗

PubMedDate not supplied

Modulation of serum concentrations of melatonin by carbamazepine and valproate.

Evidence has accumulated about the involvement of reactive oxygen species (ROS) in epilepsy. The neuromodulator melatonin has been shown to reduce oxidative stress in various animal models due to its free radical scavenging properties. The present study investigated whether carbamazepine and valproate alter serum concentrations of melatonin. Epileptic children were randomly assigned to receive carbamazepine/ valproate monotherapy till 22 patients were recruited in the study. At the tenth day, in the evening, samples were drawn for baseline endogenous melatonin estimation. The patients were then administered exogenous melatonin, and repeat samples were drawn after 30 minutes. Serum levels of melatonin were estimated using Melatonin ELISA kits. The median levels of melatonin were 165.0 pg/ml (Range 50.0-350.0) in CBZ+MEL group and 78.0 pg/ml (Range 13.0-260.0) in the VPA+MEL group. The observed difference in melatonin levels could be attributed to the difference in antiepileptic drugs, additive increase in reactive oxygen species due to disease combined with carbamazepine, or possibly to a difference in melatonin kinetics in conditions of oxidative stress.

Anticonvulsants↗

PubMedDate not supplied

Protective effect of endothelin antagonist (TAK-044) on neuronal cell viability in in vitro oxygen-glucose deprivation model of stroke.

The present study was carried to investigate the effect of endothelin antagonist (TAK-044) in an in vitro model of stroke using primary neuronal culture. Hypoxia in neuronal culture was induced for 3 h using oxygen glucose deprivation (OGD) model, thereafter cells were reperfused. In separate group cultures were incubated with graded concentrations of TAK-044 (0.01, 0.1 and 1 microg/microl) for different time duration i.e. 6, 12 and 24 hours after reperfusion. Percent cell viability was assessed 24 h after reperfusion using MTT assay. It was observed that percent cell viability was reduced to 13.7 +/- 0.4% in the cells under 3 h hypoxic condition as compared to the cells under normal condition (100%). TAK-044 at the concentrations of 0.1 and 1 microg/microl, but not at 0.01 microg/microl showed significant (P<0.01) improvement in the % cell viability as compared to the cells in hypoxic condition. Percent cell viability at the concentration of 0.1 and 1 microg/microl for 24 h time duration after reperfusion were 54.8 +/- 3.2% and 75.4 +/- 1.8% respectively as compared to the cells under hypoxic condition (13.7 +/- 0.4%). The results demonstrate the neuroprotective effect of TAK-044 against neuronal damage caused by hypoxia induced in neuronal culture.

Animals↗

PubMedDate not supplied

Drug-eluting stents: a pharmacoclinical perspective.

In 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.

Angioplasty, Balloon, Coronary↗

PubMedDate not supplied

The effect of acute and chronic treatment of verapamil on pressor response to angiotensin II in rats.

The 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.

Angiotensin II↗

PubMedDate not supplied

Effect of Ca++ channel blockers and saralasin on angiotensin II induced contraction in rabbit aortic strip.

To 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.

Angiotensin II↗

PubMedDate not supplied

Changes in circulatory biogenic amines during head-up tilt testing in neurocardiogenic syncope.

The 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.

Adolescent↗

PubMedDate not supplied

A simple device for recording seizure activity in rats.

Experimental research on epilepsy and antiepileptic drugs in rodents utilizes different models (e.g., chemical, electrical or genetic) which have different end points for evaluating seizure activity. To overcome the possibility of observer bias and the limitation of nonavailability of a hard copy of seizure activity, a simple method is described. A horizontal perspex platform is mounted on four springs of suitable tension inside a perspex chamber. A force transducer is attached to the platform to record seizure activity on paper by a physiograph. Using this assembly, the incidence, latency and duration of different seizure components, i.e., myoclonic jerks and generalized clonic seizures, after pentyleneterrazole administration (60 mg/kg i.p.) in rats were recorded. The effects of pretreatment with anticonvulsant doses of diazepam (4 mg/kg i.p.) and sodium valproate (300 mg/kg i.p.) were studied. Chemical kindling was induced by repeated, alternate-day injections of a subconvulsant dose of pentylenetetrazole (30 mg/kg i.p.) for 10 weeks and seizure activity during different stages of development of kindling was recorded. The described method not only successfully records the different seizure components but also quantifies the latency and duration of seizure activity.

Animals↗