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Biomedical subjects

R Chander

Publications and source records attributed to R Chander.

At least 19 recordsLinked to original sources
PubMed2006

Antihyperglycemic and antidyslipidemic agent from Aegle marmelos.

The plant Aegle marmelos belongs to the family of Rutaceae. From the leaves of A. marmelos an alkaloidal-amide, Aegeline 2, was isolated and found to have antihyperglycemic activity as evidenced by lowering the blood glucose levels by 12.9% and 16.9% at 5 and 24h, respectively, in sucrose challenged streptozotocin induced diabetic rats (STZ-S) model at the dose of 100mg/kg body weight. Aegeline 2 has also significantly decreased the plasma triglyceride (Tg) levels by 55% (P<0.001), total cholesterol (TC) by 24% (P<0.05), and free fatty acids (FFA) by 24%, accompanied with increase in HDL-C by 28% and HDL-C/TC ratio by 66% in dyslipidemic hamster model at the dose of 50mg/kg body weight. The reasonable mapping of compound 2 to validated pharmacophoric hypothesis and 3D QSAR model with an estimated activity (283nM) suggest that the compound 2 might be a beta(3)-AR agonist.

Adrenergic beta-3 Receptor Agonists↗
PubMed2006

A new in-vitro agglutination technique for potency estimation of antisnake venom serum (ASVS).

Traditionally the potency of ASVS is assayed quantitatively by in-vivo neutralization test for lethality in mice. A sensitive and simple in-vitro agglutination assay for the quantitative determination of Antisnake Venom Serum (ASVS) potency is reported. The method is rapid, cheap, simple, economical and above all does not require the use of experimental animals for potency assay of in process, unpurified and purified sera batches. Among in-vitro procedures, agglutination assay was favored in comparison to flocculation as the later was found to give variable results and also time consuming (high Kf value). Before application, the method was standardized and validated for choice and concentration of particulate material (latex vs. bentonite), temperature and optimum antiserum concentration. It is well known fact that venoms lose toxicity on dilution however this study demonstrated that the bentonite adsorbed venoms of the entire four snake species viz., Cobra, Krait, Russell's viper and Echis are stable even up to 30 days of storage. Among five lots each of unpurified serum, unprocessed plasma and purified sera tested, the results were found comparable with universally accepted in-vivo biological assay. The coefficient of correlation was found to be near 1.0 within 95% fiducial limits of acceptance and also significantly less variation was observed in the mean potency values and standard deviations. For all results p value was observed to be <0.01. Results indicate that in-vitro agglutination assay is suitable and can be used for potency estimation of in process as well as unpurified and purified ASVS batches.

Adsorption↗
PubMed2003

Antidyslipidemic action of fenofibrate in dyslipidemic-diabetic hamster model.

Fenofibrate is the ligand for PPARalpha subtype that mediates the action of its agonists' in lipid metabolism. How fibrate exerts hypolipidemic effect? The mechanism is studied in a newly developed high-fat fructose enriched diet induced dyslipidemia-diabetic hamster model. Fenofibrate lowered the basal plasma lipids like TC, TG, PL, FFA, glycerol, VLDL, and LDL, but HDL was increased. The activity of lipoprotein lipase in liver, adipose tissue, and small intestine was upregulated. However, that of triglyceride lipase was downregulated in liver. It has also improved the insulin secretion and plasma glucose lowering, caused by impairment in insulin secretion due to high-fat load. The drug was found effective in reducing body weight and diet due to rise in leptin level. Fenofibrate also enhanced the fecal excretion of total lipids, cholic acid, and deoxycholic acid probably by the activation of 7alpha cholesterol hydroxylase enzyme. Thus, causing broad-spectrum lipid lowering along with inhibition of hepatic lipid biosynthesis and maintaining lipid-glucose homeostasis.

Animals↗
PubMed2002

A technique for open trocar placement in laparoscopic surgery using the umbilical cicatrix tube.

BACKGROUND: Increasingly the open method for placement of the initial or first trocar is replacing the conventional technique with the Veress needle. Indeed, it is preferred because it affords peritoneal access under direct vision. A number of methods have been described in the literature using a variety of approaches and different instruments. METHODS: We describe a method of open trocar placement in the supra- or subumbilical region that follows a stepwise procedure and employs specific instruments sequentially, while utilizing the umbilical cicatrix pillar or tube. RESULTS: This technique has been done in 525 cases with no complications or port site hernias. CONCLUSION: This is a simple technique that is safe and easy to learn. It can be performed rapidly and is a reliable method for the insertion of the first port under vision.

Catheterization↗
PubMed2002

Lipid lowering activity of Phyllanthus niruri in hyperlipemic rats.

The lipid lowering activity (LLA) of Phyllanthus niruri has been studied in triton and cholesterol fed hyperlipemic rats. Serum lipids were lowered by P. niruri extract orally fed (250 mg/kg b.w.) to the triton WR-1339 induced hyperlipemic rats. Chronic feeding of this drugs (100 mg/kg b.w.) in animals simultaneously fed with cholesterol (25 mg/kg b.w.) for 30 days caused lowering in the lipids and apoprotein levels of VLDL and LDL in experimental animals. The LLA of this drug is mediated through inhibition of hepatic cholesterol biosynthesis, increased faecal bile acids excretion and enhanced plasma lecithin: cholesterol acyltransferase activity.

Administration, Oral↗
PubMed2001

Syntheses and biological evaluation of alkanediamines as antioxidant and hypolipidemic agents.

A new series of compounds belonging to N,N'- [bis (1-aryl-6-hydroxy-hex-2-ene-1-one-3-yl)-1,n-alkanediamines (2-5a-f) have been synthesized and evaluated for antioxidant and hypolipidemic activities. Amongst all the synthesized compounds, seven compounds namely 2c, 2e, 4c, 5b, 5c, 5e and 5f exhibit potent antioxidant activity. These compounds have also been evaluated for hypolipidemic activity.

Alkenes↗
PubMed2001

Endothelial dysfunction and progressive coronary atherosclerosis: sequential invasive studies in a patient with multiple cardiac risk factors.

This manuscript describes sequential angiographic, endothelial and vasoreactivity characteristics of the coronary arterial circulation in a middle-aged patient with multiple cardiac risk factors who developed hemodynamically significant coronary atherosclerosis over a 6-year period. A 56-year-old woman demonstrated marked angiographic progression of coronary atherosclerosis over time beginning with minor luminal irregularities in the setting of severe endothelial dysfunction. The association of endothelial dysfunction, ineffective cardiac risk factor management and progressive atherosclerosis is discussed.

Cardiac Catheterization↗
PubMed2000

Syntheses and biological evaluation of 3-substituted amino-1-aryl-6-hydroxy-hex-2-ene-1-ones as antioxidant and hypolipidemic agents.

A new series of compounds belonging to 3-substituted amino-1-aryl-6-hydroxy-hex-2-ene-1-ones (4-12a-e) have been synthesized and evaluated for antioxidant and hypolipidemic activities. Amongst all the synthesized compounds, seven compounds, namely 5b, 5d, 6e, 8a, 8b, 10b and 11a, exhibit better antioxidant activity than probucol. Two compounds, 5d and 10b, have been evaluated in detail for antioxidant and hypolipidemic activities and show comparable activity profile to that of probucol and guggulipid. From the present study it may be postulated that the mechanism of action of these compounds could be through activation of lecithin cholesterol acyltransferase (LCAT), liver lipolytic activity, increased faecal bile acid secretion and inhibition of hepatic cholesterol biosynthesis.

Alkenes↗
PubMed1999

Multiple familial keratoacanthoma of Witten and Zak - A report of three siblings.

Three out of 11 siblings of a nonconsanguineous marriage suffering from biopsy-proven multiple small eruptive keratoacanthoma (KA) of Grzybowski as well as large nodular KA of Ferguson-Smith are reported. The response to oral methotrexate was not encouraging. Intravenous 5-fluorouracil (5-FU) at a dose of 12 mg/kg/day in isotonic saline given in weekly 5-day cycles resulted in almost complete resolution of small eruptive lesions and signs of involution in older large agglomerate noduloulcerative KA after 6 cycles. Thus, intravenous 5-FU was found to be an effective therapeutic modality for the Witten and Zak type of KA.

Adult↗
PubMed1999

Immunomodulation of macrophages by radio-detoxified lipopolysaccharide of Salmonella typhimurium.

Lipopolysaccharide (LPS) and ratio-detoxified LPS (Rd-LPS) from Salmonella typhimurium were analysed for their ability to stimulate murine peritoneal exudate cells (PEC) and macrophages. Rd-LPS induced much more inflammatory response as compared to LPS. PEC numbers/mouse obtained were significantly higher (3-fold) in response to Rd-LPS than LPS. The haemorrhage was induced in mice by LPS but not by Rd-LPS. Activation of macrophages in vivo by Rd-LPS was significantly higher as compared to LPS. This was evident from the increase levels of their lysosomal enzymes and cytokines. Rd-LPS induced 10-fold increase in acid phosphatase contents of macrophages as compared to controls while only 7-fold increase was obtained with LPS. Arylsulfatase and beta-glucuronidase increased by about 2-fold by Rd-LPS and LPS. Macrophages incubated with Rd-LPS in vitro showed 16-fold and 20-fold increase in the cell associated levels of arylsulfatase and beta-glucuronidase respectively as compared to unstimulated cells. On the other hand, only 6-fold increase was observed in response to LPS in the levels of both the enzymes. TNF-[symbol: see text] and IL-1 secreted by macrophages increased considerably in response to Rd-LPS as compared to those released by LPS. Rd-LPS, thus seems to be a better immunomodulator than untreated LPS.

Adjuvants, Immunologic↗
PubMed1999

Hepatoprotective activity of ellagic acid against carbon tetrachloride induced hepatotoxicity in rats.

Administration of CCl4 to normal rats and consequent oral feeding with ellagic acid (50 mg/kg) provided a significant protection against the biochemical alterations in serum and liver produced by CCl4. In vitro experiments showed that liver microsomes from animals treated with ellagic acid and CCl4, decreased lipid peroxidation compared to microsome prepared from rats exposed to CCl4 alone.

Animals↗
PubMed1998

Picroliv prevents oxidation in serum lipoprotein lipids of Mastomys coucha infected with Plasmodium berghei.

Picroliv, an iridoid glycoside mixture from the root and rhizome of Picrorhiza kurrooa, at the dose of 6 mg/kg p.o. for two weeks provided significant protection against the generation of lipid peroxidation products in serum beta-lipoproteins of P. berghei infected M. coucha. Incubation of normal rat hepatocytes with very low density lipoprotein or low density lipoprotein isolated from infected animals caused significant generation of lipid peroxides followed by a decrease in the viability of these cells, however these effects were partially reversed with the lipoproteins from infected and picroliv treated groups. High density lipoprotein from infected animals was not toxic to hepatocytes in vitro.

Animals↗
PubMed1998

Effect of gamma irradiation on chemical and biological properties of lipopolysaccharide from Salmonella typhimurium.

Lipopolysaccharide (LPS) from S. typhimurium on exposure to gamma-radiation resulted in decrease in toxicity and was less mitogenic, Silver stained profiles of irradiated LPS on polyacrylamide gels revealed complete loss of its heteropolysaccharides which was confirmed further by analysing lipid A and LPS from Salmonella minnesota Re mutants on SDS-PAGE. Glucosamine and 2-keto 3-deoxy-octonate(Kdo) contents were significantly decreased on treatment. Lipid A obtained by removal of heteropolysaccharides from LPS was less toxic on exposure to gamma radiations.

Animals↗