Biomedical subjects

V S Ghole

Publications and source records attributed to V S Ghole.

10 recordsLinked to original sources

PubMed2005

Effect of Diabecon on sugar-induced lens opacity in organ culture: mechanism of action.

Cataract is the leading cause of blindness worldwide. Apart from ageing, diabetes has been considered to be one of the major risk factors of cataract. The high sugar levels in diabetes may cause tissue disruption and intumescences by osmotic changes induced via aldose reductase (AR) mediated polyol pathway. Therefore, agents that can inhibit AR and prevent sorbitol accumulation may be helpful to combat sugar-induced cataract. In the present study, AR inhibitory activity of Diabecon (an herbal drug used for diabetes) was studied together with its effect against sugar-induced lens opacity in organ culture. Diabecon aqueous extract (DAE) showed potential inhibitory activity with an IC50 value of 10 microg/ml against rat lens AR. Incubation of goat lens with supraphysiological concentrations of glucose (100 mM) led to the loss of lens transparency associated with increased AR activity, decreased soluble protein and increased protein carbonyls and glycation. Addition of DAE (0.3 mg/ml) to the medium preserved transparency and ameliorated the decrease in lens soluble protein due to hyperglycemia and also prevented the formation of glycated protein. Interestingly DAE inhibited aldose reductase activity in lens incubated with 100 mM glucose. DAE decreased protein carbonyls, prevented the loss of beta(L)-crystallin against 100 mM of glucose. We have also demonstrated here that most of these effects are mainly due to Gymnema sylvestre, one of the constituent herbs of Diabecon. These results suggest that Diabecon protect the lens against sugar-induced cataract by multiple mechanisms.

Aldehyde Reductase↗

PubMed2005

Rapid method for the preparation of an AGE-BSA standard calibrator using thermal glycation.

Estimation of advanced glycation end products (AGEs) by determining fluorescence is based on the use of a standard calibrator prepared by incubating bovine serum albumin (BSA) and glucose at 37 degrees C for 60 days. In the present study we attempted to reduce the duration of incubation to 4 days by increasing the temperature to 50 degrees C. It is noteworthy that incubation at 50 degrees C resulted in the rapid production of an AGE-BSA standard calibrator within 4 days. Aminoguanidine reduced the intensity of the glycation-induced fluorescence, while the addition of lysine intensified the reaction, as shown by the calibrator incubated at 37 degrees C. The protein carbonyl content was shown to increase in the rapidly-formed standard calibrator. Thus we conclude that a simple increase in temperature and the addition of lysine (0.1M) can accelerate the process of glycation-induced fluorescence. This calibrator can be used effectively in fluorescence assays of AGEs.

Calibration↗

PubMed2004

Glutathione and cinnamic acid: natural dietary components used in preventing the process of browning by inhibition of Polyphenol Oxidase in apple juice.

Consumer demands for 'freshness' in processed foods has been given increasing attention by food processing industries by searching for minimally processed products. Polyphenol Oxidase (PPO) mediated browning is a major cause of undesirable flavors and nutritional losses in fruit juices. Here the anti-browning efficiency of glutathione (GSH, reduced form) and cinnamic acid (CA) in apple juice is evaluated. It was observed that the rate of the browning reaction could be efficiently delayed using GSH and CA, which act as inhibitors of PPO. Kinetic studies confirm that GSH and CA are non-competitive and competitive inhibitors of PPO respectively.

Beverages↗

PubMed2003

Comparative quantitation for the protein content of diphtheria and tetanus toxoids by DC protein assay and Kjeldahl method.

DPT, a combination vaccine against diphtheria, tetanus and pertussis is available since many years and still continued in the national immunisation schedule of many countries. Although highly potent, reactions to DPT vaccine are well known, mainly attributed to the factors like Pertussis component, aluminum adjuvant and lower purity of tetanus and diphtheria toxoids. The latter most important aspect has become a matter of concern, specially for the preparation of next generation combination vaccines with more number of antigens in combination with DPT. Purity of toxoid is expressed as Lf (Limes flocculation) per mg of protein nitrogen. The Kjeldahl method (KM) of protein nitrogen estimation suggested by WHO and British Pharmacopoeia is time consuming and less specific. Need has been felt to explore an alternative method which is quick and more specific for toxoid protein determination. DC (detergent compatible) protein assay, an improved Lowry's method, has been found to be much more advantageous than Kjeldahl method.

Chemistry Techniques, Analytical↗

PubMed2003

Kinetics of inhibition of polyphenol oxidase mediated browning in apple juice by beta-cyclodextrin and L-ascorbate-2-triphosphate.

Polyphenol Oxidase (PPO) mediated browning in raw fruits and vegetables is a major cause of quality deterioration in fruits and vegetables and derived food products. Here the rate of browning reaction in apple juice treated individually and in combination (1:1) of beta-Cyclodextrin (beta-CD) and L-Ascorbate-2-triphosphate (L-AATP) is described. It was observed that the rate of quinone formation can be minimized using a combination of beta-CD and L-AATP as compared to individual treatment with these agents. Kinetic experiments revealed that both compounds are non-competitive inhibitors of PPO.

Ascorbic Acid↗

PubMed2000

Neonatal gram-negative bacteremia.

A 22 months prospective study of neonatal gram-negative bacteremia was undertaken in a 15 bed NICU to find out the incidence and antibiotic resistance patterns. Clinically suspected 1326 cases of neonatal sepsis were studied during this period. More than 25% of the cases were microbiologically positive for sepsis. Among 230 (67.2%) cases of gram-negative bacteremia, the predominant isolates were Pseudomonas aeruginosa (38.3%), Klebsiella pneumoniae (30.4%), Escherichia coli (15.6%) and Acinetobacter sp. (7.8%). Fifty-nine per cent of the neonates were born in hospital while 41% were from community and referral cases. Lower respiratory tract infection, umbilical sepsis, central intravenous line infection and infection following invasive procedures were the most commonly identified sources of septicemia. Prematurity and low birth weight were the main underlying conditions in 60% of the neonates. Total mortality was 32%. Increased mortality was mainly associated with neutropenia, nosocomial infection and inappropriate antibiotic therapy. Resistance was increasingly noted against many antibiotics. The isolates were predominantly resistant to extended spectrum cephalosporins (25%-75%), piperacillin (68%-78%), and gentamicin (23%-69%). The commonest microorganisms causing gram-negative bacteremia were Pseudomonas aeruginosa followed by Klebsiella pneumoniae. The community-acquired bacteremia was mainly due to E. coli. The proportion of preterm and low birth weight babies was significantly high, and the major contributing factor in total mortality. Sensitivity to different antibiotics conclusively proved that a combination of ampicillin + sulbactam with amikacin or ampicillin + sulbactam with ciprofloxacin is most effective.

Bacteremia↗

PubMed1997

Effect of endotoxemia on plasma and tissue levels of nitric oxide metabolites and guanidino compounds.

The effect of endotoxemia on the levels of amino acids, nitrates, nitrites and guanidino compounds was investigated. Plasma levels of nitrate and nitrite were significantly increased indicating increased production of nitric oxide during endotoxemia. Plasma concentrations of alanine, glutamine, leucine, methionine, phenylalanine, proline and taurine were also significantly elevated. These results indicate that endotoxin produces a hypercatabolic state. The plasma concentration of arginine was significantly decreased whereas the concentrations of ornithine and urea, the catabolites of arginine were increased. Decreased plasma arginine coupled with increased plasma ornithine and urea indicate that arginine catabolism is increased and arginine synthesis is decreased during endotoxemia. Plasma levels of creatine, creatinine, guanidine and guanidinosuccinic acid were significantly elevated whereas homoarginine levels were significantly decreased. Nitric oxide synthase utilizes arginine as well as homoarginine as substrates. The decreased concentration of both substrates may be related to alterations in nitric oxide synthase activity during endotoxemia. These results suggest that in addition to nitric oxide, other catabolites of arginine such as guanidino compounds may be important in the pathophysiology of endotoxemia. Because of the marked increase in guanidinosuccinic acid, a known uremic toxin, we speculate that guanidinosuccinic acid may be important in the pathophysiology of endotoxemia.

Amino Acids↗

PubMed1997

Intestinal ischemia and reperfusion injury in transgenic mice overexpressing copper-zinc superoxide dismutase.

Superoxide dismutase (SOD) scavenges oxygen radicals that are implicated in the pathogenesis of intestinal ischemia-reperfusion injury. The effect of intestinal ischemia and reperfusion was investigated in transgenic mice overexpressing human Cu-Zn SOD. Ischemia was induced by occluding the superior mesenteric artery. Myeloperoxidase activity was determined as an index of neutrophil infiltration, and malondialdehyde levels were measured as an indicator of lipid peroxidation. Forty-five minutes of intestinal ischemia followed by 4 h of reperfusion caused an increase in intestinal levels of malondialdehyde in both nontransgenic and transgenic mice, but the concentration of malondialdehyde was significantly greater in nontransgenic mice. Intestinal ischemia-reperfusion also caused an increase in intestinal and pulmonary myeloperoxidase activity in nontransgenic and transgenic mice, but the transgenic mice had significantly lower levels of myeloperoxidase activity than nontransgenic mice. Transgenic mice had higher levels of intestinal SOD activity than nontransgenic mice. There were no significant differences in the catalase or glutathione peroxidase activities. In conclusion, our study demonstrates that the overexpression of SOD protects tissues from neutrophil infiltration and lipid peroxidation during intestinal ischemia-reperfusion.

Animals↗

PubMed1993

Effect of urease-induced hyperammonemia on metabolism of guanidino compounds.

We previously reported that guanidino compounds produced by the catabolism of arginine play an important role in the pathophysiology of acute hyperammonemia. In order to understand the metabolism of guanidino compounds during sustained hyperammonemia, we investigated the effect of intraperitoneal urease injection (800 IU/kg) on the levels of guanidino compounds in blood, liver, kidney, and brain of rats. Control rats received an equal volume of saline. Eight hours following injection, rats were sacrificed and blood and tissues were removed. Ammonia and urea were determined by enzymatic and colorimetric assays, respectively. Guanidino compounds were analyzed by high-performance liquid chromatography. Blood and tissue ammonia were significantly increased and urea decreased in urease-treated animals. Blood and kidney arginine levels were significantly decreased although hepatic arginine was increased following urease injection. Elevated hepatic arginine may be due to the rapid conversion of urea to ammonia by urease and the development of a futile urea cycle. Catabolites produced by the transamidination of arginine were significantly decreased in the blood, liver, kidney, and brain of urease-treated rats, whereas acetylation of hepatic arginine to alpha-N-acetylarginine was increased. Blood and tissue guanidinosuccinic acid levels were not elevated during urease induced hyperammonemia, supporting the hypothesis that urea is a precursor for the synthesis of guanidinosuccinic acid.

Ammonia↗

PubMed1993

Regulation of orotic acid biosynthesis and excretion induced by oral glutamine administration in mice.

Glutamine, the most abundant amino acid in blood and tissues, is degraded by the renal and splanchnic tissues, especially the small intestinal mucosa. Due to the activity of glutaminase, it may be broken down in these tissues and contribute to ammoniagenicity. Glutamine, either directly or through ammonia production, may act as a nitrogenous source for pyrimidine biosynthesis. We have evaluated the effect of glutamine on orotate metabolism in mice, by gavaging (ig) L-glutamine, 1.0 to 4.0 mmol/100 g of body wt/day, during 6 weeks of experimentation. Glutamine at doses of 2.5 to 4.0 mmol/100 g of body wt caused a significant increase in plasma ammonia and urinary orotate. The regulation of the orotic acid biosynthesis and excretion was studied by testing the effects of various inhibitors in mice force-fed with glutamine (4 mmol/100 g of body wt, ig). The orotic aciduria was insensitive to acivicin (1 and 5 mg/100 g of body wt, ip), a specific inhibitor of the cytoplasmic carbamyl phosphate synthetase-II, thus pointing toward the mitochondrion as the principal source of carbamyl phosphate. Cycloheximide (15 and 100 mg/kg of body wt, ip) caused a significant decrease in urinary orotate indicating that the induction of orotate synthesis by glutamine may be associated with the translation of a specific protein. However, orotate excretion was significantly decreased by N-(phosphonoacetyl)-L-aspartate (PALA) (5 mg/100 g of body wt, ip) due to its inhibitory effect on the aspartate transcarbamylase activity. There was a significant increase of urinary orotate following ingestion of adenine supplemented diets (0.1% and 0.2%), suggesting the blockage of the utilization of orotate for nucleotide biosynthesis by glutamine. Since orotate synthesis may also be influenced by ornithine metabolism, we evaluated the effect of glutamine administration on various ornithine-metabolizing enzymes. There was a decrease in hepatic ornithine decarboxylase activity with no change in hepatic ornithine aminotransferase activity following the administration of glutamine. This observation indicates that an increased metabolic utilization of ornithine is not responsible for the increase in orotate excretion, which may be caused principally through an effect of glutamine on mitochondrial carbamyl phosphate synthesis.

Administration, Oral↗