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Biomedical subjects

K C Singhal

Publications and source records attributed to K C Singhal.

At least 19 recordsLinked to original sources
PubMed2005

Antifilarial activity of Azadirachta indica on cattle filarial parasite Setaria cervi.

Alcohol and aqueous extracts of flowers of Azadirachta indica were tested in vitro for their potential antifilarial activity against whole worm, nerve muscle (n.m.) preparation and microfilariae of Setaria cervi. The effects of alcohol and aqueous extracts were similar in nature on the spontaneous movements of whole worm and nerve muscle preparation. On the whole worm, the response was characterized by initial increase in tone, rate and amplitude of contractions followed by reversible paralysis. The initial stimulant effect is likely to be due to irritant effect on the cuticle. Nerve muscle preparation responded to both extracts by inhibition of spontaneous movements followed by reversible paralysis; initial stimulation phase was absent. The inhibition was concentration related. Alcohol and aqueous extracts had almost similar lethal effect on the microfilariae of S. cervi, the LC50 being 15 and 18 ng/ml, respectively.

Animals↗
PubMed2005

Potential antifilarial activity of fruit extracts of Ficus racemosa Linn. against Setaria cervi in vitro.

Effect of alcoholic and aqueous extracts of the fruits of F. racemosa Linn., on the spontaneous movements of both the whole worm and nerve muscle preparation of Setaria cervi and on the survival of microfilariae in vitro was studied. Alcoholic as well as aqueous extracts caused inhibition of spontaneous motility of whole worm and nerve muscle preparation of Setaria cervi characterized by increase in amplitude and tone of contractions. Initial stimulatory effect was not observed with aqueous extract on whole worm preparation, while effect of alcoholic extract on whole worm and nerve muscle preparation was characterized by an increase in amplitude and tone of contractions followed by paralysis. The concentrations required to inhibit the movement of the whole worm and nerve muscle preparation for alcoholic extract of fruits of F. racemosa were 250 and 50 microg/ml, respectively, whereas aqueous extract caused inhibition of the whole worm and nerve muscle preparation at 350 and 150 microg/ml, respectively, suggesting a cuticular barrier. Both alcoholic and aqueous extracts caused death of microfilariae in vitro. LC50 and LC90 were 21 and 35 ng/ml, respectively for alcoholic, which were 27 and 42 ng/ml for aqueous extracts.

Animals↗
PubMed2003

Anti fi larial potential of the fruits and leaves extracts of Pongamia pinnata on cattle filarial parasite Setaria cervi.

The effect of aqueous and alcohol extracts of the fruits and leaves of Pongamia pinnata (Linn.) Merr. (Syn. Pongamia glabra Vent, leguminosae) on the spontaneous movements of both the whole worm and the nerve-muscle preparation of Setaria cervi and on the survival of micro fi lariae in vitro was studied. The aqueous and alcohol extracts of fruits and the alcohol extract of leaves caused an inhibition of spontaneous movements of the whole worm and the nerve-muscle preparation of S. cervi. The initial stimulatory effect was not observed with the aqueous extract of fruits on the nerve-muscle preparation. The concentration required to inhibit the movements of the whole worm preparation was 250 micro g/mL for aqueous, 120 micro g/mL for alcohol extract of fruits and 270 microgram/mL for alcohol extracts of the leaves. The concentrations of P. pinnata extracts required to produce an equivalent effect on the nerve-muscle preparation were 25 micro g/mL, 5 micro g/mL and 20 micro g/mL, respectively, suggesting a cuticular permeability barrier.

Animals↗
PubMed2002

Potential antifilarial activity of the leaves and seeds extracts of Psoralea corylifolia on cattle filarial parasite Setaria cervi.

The effect of aqueous and alcohol extracts of the leaves and seeds of Psoralea corylifolia, on the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi and on the survival of microfilariae in vitro was studied. Alcohol extracts of both leaves and seeds caused the inhibition of spontaneous movements of the whole worm and the nerve muscle preparation of S. cervi, characterised by initial, short lasting small increase in tone of contractions followed by paralysis. The initial stimulatory effect was not observed by alcohol extract of leaves on nerve muscle preparation. The concentrations required to inhibit the movements of whole worm and nerve muscle preparations for alcohol extracts of leaves and seeds were 160, 30, and 150, 20 microg/ml, respectively suggesting a cuticular permeability barrier. Alcohol extracts of both leaves and seeds caused death of microfilariae in vitro, LC(50) and LC(90) being 15 and 25 ng/ml for alcohol extract of leaves and 12 and 18 ng/ml for alcohol extract of seeds, respectively.

Animals↗
PubMed2001

Voltage activated calcium channels in somatic muscle of filarial nematode Setaria cervi.

Acetylcholine (Ach), levamisole and pyrantel pamoate all cause stimulation of spontaneous rhythmic movements of whole worm and nerve muscle preparation of filarial nematode Setaria cervi. These stimulant effects are manifested only in the presence of available Ca2+ or extracellular Ca2+. Electrical stimulation of nerve muscle preparation of Setaria cervi elicited depolarization and increase in amplitude and tone of contractions. Electrical current stimulates Ca2+ entry leading to depolarization and during the phase of depolarization addition of any of the three stimulants viz. Ach, levamisole or pyrantel pamoate fails to elicit any response on nerve muscle preparation. The findings indicate that electrical stimulation, excitatory neurotransmitter Ach and stimulant anthelmintics levamisole and pyrantel pamoate all produce their stimulant effect by triggering entry of Ca2+ into the muscle cell. Further, blocking the calcium channels by nifedepine and thereby the entry of Ca2+ into the cells blocks the stimulant effect of Ach levamisole and pyrantel pamoate.

Animals↗
PubMed2000

Exploration of antifilarial potential and possible mechanism of action of the root extracts of Saxifraga stracheyion on cattle filarial parasite Setaria cervi.

The effect of aqueous and alcohol extracts of the roots of Saxifraga stracheyi Engl. On the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi and on the survival of microfilariae in vitro was studied. Both extracts caused the inhibition of spontaneous movements of the whole worm and the nerve-muscle preparation of S. cervi, characterized by an increase in the amplitude and a decrease in the rate of contractions, while the tone of the contractions remained visibly unaffected. The concentration required to inhibit the movements of the whole worm preparation was 140 microg/ml for the aqueous and 250 microg/ml for the alcohol extract. The concentration of S. stracheyi extracts required to produce an equivalent effect on the nerve-muscle preparation was 30 microg/ml for aqueous, and 20 microg/ml for the alcohol extract, suggesting a cuticular permeability barrier.

Animals↗
PubMed1998

5/6/7/8 mono or disubstituted 1H/1-phenyl-9H-pyrido [3,4 b] indoles--a new class of antifilarial agents and their relationship with voltage sensitive calcium channels in Setaria cervi.

Synthetic compounds of 5/6/7/8 mono or disubstituted 1H/1-phenyl-9H pyrido (3,4 b) indole series were screened for their antifilarial activity in vitro by observing their effect on the spontaneous movements of the whole worm and nerve muscle preparation of S. cervi (Nematoda:Filarioidea). Of the 10 compounds tested only compound 87/581 was able to modify the movements of whole worm and nerve muscle preparation. This compound caused inhibition of spontaneous motility of whole worm and nerve muscle preparation of S. cervi characterized by initial short lasting stimulation followed by irreversible paralysis. The concentration required to inhibit the movements of n.m. preparation was 10 micrograms/ml as compared to 25 micrograms/ml for the whole worm preparation, suggesting a cuticular permeability barrier. Prior addition of compound 87/581 to the bath fluid blocked the calcium ion dependent stimulant effect of Ach and pyrantel pamoate. Further the initial stimulant effect of the compound was blocked by prior addition of nifedipine a calcium channel blocker. The findings suggest that the action is due to blockade of voltage sensitive calcium channels.

Animals↗
PubMed1997

Antifilarial activity of Mallotus philippensis Lam. on Setaria cervie (Nematoda: Filarioidea) in vitro.

The effect of aqueous and alcoholic extracts of the leaves of Mallotus philippensis (Lam.) Muell. Arg. was studied on the spontaneous movements of the whole worm and nerve-muscle (n.m.) preparation of Setaria cervi and on the survival of microfilariae in vitro. Both the extracts caused inhibition of spontaneous motility of whole worm and the n.m. preparation of S. Cervi characterized by initial stimulation followed by depression in amplitude. The tone and rate of contractions remained visibly unaffected. Aqueous extract at higher concentration showed immediate reduction in tone. The concentration required to inhibit the movements of n.m. preparation was 1/5th for aqueous and 1/11th for alcoholic extract compared to that for the whole worm, suggesting a cuticular permeability barrier. The stimulatory response of acetylcholine was blocked by aqueous extract on whole worm movements. On the microfilariae the LC50 and LC90 were 18 and 20 ng/ml for aqueous and 12 and 15 ng/ml for alcoholic extracts respectively.

Animals↗
PubMed1997

Potential antifilarial activity of roots of Asparagus adscendens Roxb, against Setaria cervi in vitro.

Effect of aqueous and alcoholic extracts of the roots of A. adscendens was studied on the spontaneous movements of whole worm and nerve muscle (n.m.) preparation of S. cervi and on the survival of microfilariae in vitro. Aqueous as well alcoholic extracts caused inhibition of spontaneous motility of whole worm and n.m. preparation of S. cervi characterized by initial, short lasting small increase in amplitude and tone of contractions followed by paralysis. The initial stimulatory effect was not observed by aqueous extract on n.m. preparation. The concentration required to inhibit the movements of n.m. preparation was 1/4th for aqueous and 1/3rd for alcoholic extract suggesting a cuticular permeability barrier. The effect of acetylcholine on n.m. preparation was concentration related being more with a concentration of 5 micrograms/ml as compared to 1 microgram/ml. Both alcoholic as well as aqueous extracts caused death of microfilariae in vitro, LC50 and LC90 being 8 and 16 ng/ml for aqueous, 3 and 12 ng/ml for alcoholic extracts respectively.

Animals↗
PubMed1996

A study of effect of guggulsterone on hyperlipidemia of secondary glomerulopathy.

Hyperlipidemia in patients of secondary glomerulopathies, a well established entity with very little knowledge of its management modifies its prognosis by predisposing these patients to develop atherosclerosis, coronary artery disease, hypertension cerebro-vascular accidents and also thromboembolic phenomenon leading to renal vein thrombosis and renal failure. Guggulsterone was administered orally in these patients in a daily divided dose of 75 mg for a period of 8 weeks together with supportive measures like high protein diet, diuretics and hematinics. Total serum lipid, total serum cholesterol, triglycerides, phospholipids, HDL, LDL, and VLDL were analysed at 4 and 8 weeks of therapy. Significant reduction was observed in the values of total serum lipid and total serum cholesterol. Other parameters of lipid profile showed downward trend except rise of HDL with insignificant difference. There was no significant side effect throughout the study.

Adolescent↗
PubMed1996

Effects of oral lithium on the action of various C.N.S. active drugs.

Effects of prolonged lithium administration was seen on the action of various psychoactive drugs in animals. Apomorphine induced pecking in pigeons increased significantly by lithium treatment for 14 days, from 1445.3 +/- 202.5 in control to 2785.8 +/- 205.8 in Gp. B. Haloperidol-induced catalepsy score in albino rats increased significantly following chronic lithium treatment compared to control. Chlorpromazine-induced hypothermia in rabbits was immediate but transient, while in lithium treated rabbits induction of hypothermia was delayed, sustained and of greater magnitude. This action of lithium may be mediated by increasing the permeability of blood-brain barrier, or enhancing the sensitivity of alpha-adrenoceptors in brain.

Administration, Oral↗
PubMed1996

Regulation of cholinomimetic action of pyrantel pamoate by calcium channels in Setaria cervi.

Nerve muscle preparation of Setaria cervi (Nematoda:Filarioidea) exhibits spontaneous rhythmical movements when suspended in isolated organ bath containing modified Ringer's solution. Pyrantel pamoate (50 ng/ml) when applied caused initial short lasting stimulation followed by irreversible paralysis. When suspended in calcium free bathing fluid the movements of n.m. preparation showed a gradual decrease both in amplitude and rate of contraction til the movements ceased completely. The effect was similar when EDTA was added to the bath fluid. The stimulant effect of Pyrantel pamoate was blocked in calcium free solution and in bath applied EDTA. Calcium channel blocker Nifedipine in a concentration of 500 ng/ml blocked the effect of Pyrantel pamoate (50 ng/ml). Neither stimulation nor depression of movements was evident with higher concentration of PP (250 mg/ml) the stimulant effect of Pyrantel pamoate was blocked while the depressant effect characterized by decrease in amplitude of calcium is essential for the stimulant effect of Pyrantel pamoate and its response on n.m. preparation is similar to Acetylcholine.

Acetylcholine↗
PubMed1996

Albendazole therapy in orbital cysticercosis.

A patient with orbital cysticercosis is being presented, where albendazole therapy was successfully used. Serial CT scans of the lesions showed definite signs of resolution. The role of albendazole therapy in cysticercosis has been discussed. The relevant literature has been reviewed in brief.

Adult↗
PubMed1995

Lipofuscin pigment in cerebellar Purkinje neurones and choroid plexus epithelial cells of macaque monkeys with Plasmodium knowlesi cerebral malaria: an electron microscopical observation.

Experimental infection of rhesus monkeys (Macaca mulatta) with a virulent (W1) strain of Plasmodium knowlesi resulted in cerebral malaria. Electron microscopical examination of the brain revealed large numbers of intracytoplasmic lipofuscin pigment deposits in cerebellar Purkinje neurones and choroid plexus epithelium of the lateral ventricle. This lesion may be part of the nervous system response to ischaemic hypoxia.

Animals↗
PubMed1995

Identification of voltage-sensitive calcium channels in Setaria cervi (Nematoda: Filarioidea) and their role in regulation of spontaneous motility.

Whole worm of Setaria cervi and its nerve muscle preparation exhibit rhythmical movements when suspended in modified Ringer's solution in an isolated organ bath. Deprivation of calcium from the bathing fluid results in gradual reduction in the amplitude and rate of contraction till the movements ceased completely. Similar results were obtained by adding EDTA (5 micrograms/ml) to the bath. The effect was concentration related and was evident early with higher concentration of EDTA. Acetylcholine which increases spontaneous movements of the whole worm as well as N.M. preparation failed to do so when the movements were inhibited either in calcium free solution or in the presence of EDTA. Addition of calcium channel blocker, Nifedipine to the bathing fluid also resulted in concentration related reduction of movements of the preparation of Setaria. Further, the stimulant response of Ach was also reduced by Nifedipine and this too was related to the concentration of calcium channel blocker in the bath. The evidence clearly indicates that presence of calcium is essential for the stimulant response of Ach on S. cervi, which like mammalian tissues contain calcium channels that can be blocked by specific blocking agents.

Acetylcholine↗
PubMed1994

Evaluation of PGE2 gel for cervical ripening and induction of labour.

In a prospective study a single dose PGE2 gel 0.5 mg was given in 97 Low Bishop Score subjects, 12 hrs prior to indicated oxytocin or PGE2 tab induction for cervical ripening. Analysis of 97 subjects shows that it is very highly effective. 56 primi and 21 multi delivered spontaneously with gel administration only while 4 primi and 2 multi delivered vaginally following oxytocin and 3 more cases delivered vaginally following PGE2 tab administration and fewer caesarian section (11) were performed. The endo cervical administration of PGE2 was well tolerated and systemic PGE2 effects were minimal.

Administration, Oral↗