A simultaneous liquid chromatography/mass spectrometric assay of glutathione,cysteine, homocysteine and their disulfides in biological samples

A liquid chromatography/mass spectrometric (LC/MS) method was developed for simultaneous detection and quantitation of glutathione (GSH), glutathione disulfide (GSSG), cysteine (CysSH), homocysteine (HCysSH) and homocystine in biological samples (rat brain, lung, liver, heart, kidneys, erythrocytes and plasma). Thiols were derivatized with a large excess of Ellman's reagent, a thiol-specific reagent, to ensure an instantaneous and complete derivatization. The derivatization blocked the oxidation of the thiols to disulfides, preventing errors caused by thiol oxidation. The samples were then analyzed by LC/MS. The method provides a highly selective and sensitive assay for these endogenous thiols and their corresponding disulfides. The detection limits for GSH, GSSG, CysSH, HCysSH and homocystine were 3.3, 3.3, 16.5, 29.6 and 14.9 pmol, respectively. An attempt for cystine analysis was unsuccessful due to earlier elution of the compound and strong interferences caused by other endogenous compounds. This method will be a useful tool in the investigation of the roles of these important thiol-containing compounds and their corresponding disulfides in physiological and pathological processes.     

Serum magnesium level among pregnant women in a rural community of Haryana State, India

OBJECTIVE: Assessment of serum magnesium levels among pregnant women in a rural community. DESIGN: A community-based cross-sectional study. SETTING: Investigation was conducted in six villages of a rural block of District Faridabad, Haryana State, India. SUBJECTS: In total, 283 pregnant women with pregnancy duration of 28 weeks and more were enrolled for the detailed study. Blood from the antecubital vein was drawn and serum magnesium levels were estimated by the atomic absorption spectrophotometric method. RESULTS: In all, 44% of the pregnant women had serum levels less than the normal level (1.80 mg/dl). There was a significant decrease (P=0.01) in serum magnesium levels with the increase in parity. CONCLUSION: A high prevalence of magnesium deficiency was found among the pregnant women.     

Chemopreventive effects of dietary mustard oil on colon tumor development

Fatty acid composition of dietary fat is one of the detrimental factors in colon cancer development. Fats containing omega 6-polyunsaturated fatty acids (e.g. corn oil) enhance and omega 3-polyunsaturated fatty acids (e.g. fish oil) reduce chemically-induced colon cancer in animal studies. The purpose of this study is to investigate the effects of dietary mustard oil (containing omega 3-polyunsaturated fatty acid) on azoxymethane-induced colon cancer in rats and compare with corn and fish oil treated groups. Colon tumor incidence and multiplicity were found to be 90, 75, and 50% and 1.7, 0.8, and 0.4 tumors/rat in corn, fish and mustard oil treated groups respectively. Omega-3 polyunsaturated fatty acid levels were highest in serum and colon microsomal fractions of the fish oil group followed by the mustard oil group. Corn oil group had the highest level of omega 6-polyunsaturated fatty acid levels in serum and colon microsomal fractions. The results indicate that dietary mustard oil is more effective in preventing colon cancer in rats than dietary fish oil.     

Reversal of cadmium induced oxidative stress by chelating agent, antioxidant or their combination in rat

The influence of an antioxidant agent such as N-acetyl cysteine (NAC) or mannitol on the cadmium chelating ability of monoisoamyl 2,3-dimercaptosuccinate (MiADMS) was investigated in cadmium pre-exposed rats. This ester of 2,3-dimercaptosuccinic acid (DMSA), an accepted drug for lead poisoning, being lipophilic in nature was expected to be an efficient cadmium chelator. The treatment of cadmium intoxicated animals with MiADMS reversed cadmium induced increase in blood catalase, superoxide dismutase (SOD) and malondialdehyde (MDA), liver MDA and brain SOD and MDA levels but not the decrease in blood, liver brain reduced glutathione (GSH) and increase in oxidized glutathione (GSSG) levels, consistent with the lowering of tissue cadmium burden. The administration of NAC or mannitol reversed the cadmium induced alterations in blood and liver GSH, GSSG, blood catalase, SOD, MDA, liver SOD, MDA and brain MDA levels without lowering blood and tissue cadmium contents. However, treatments with the combination of MiADMS and NAC or MiADMS and mannitol reversed these alterations as well as reduced blood and tissue cadmium concentrations. The combined treatment with MiADMS and mannitol was better than that with MiADMS and NAC, and was significantly more effective in normalizing blood, liver GSH, GSSG, brain GSSG, and their GSH/GSSG ratios than that by either of them alone. The combined treatments also improved liver and brain endogenous zinc levels, which were decreased due to cadmium toxicity. The results suggest that the administration of an antioxidant during chelation of cadmium may provide beneficial effects by reducing oxidative stress without its cadmium removing ability.     

Lead poisoning in cattle and buffalo near primary lead-zinc smelter in India

Varying degrees of lead (Pb) poisoning was recorded in cows and buffaloes near a primary lead-zinc smelter in India. Affected animals had history of clinical signs characterized by head pressing, violent movement, blindness and salivation. These animals revealed considerably high lead levels in blood (1.43 +/- 0.07 ppm) and milk (0.75 +/- 0.19 ppm). Animals from the same place without the history of clinical signs suggestive of Pb poisoning recorded lower blood Pb levels than the affected animals; however, their blood Pb was higher than that reported for cattle in rural and urban areas of India. Affected animals also carried high levels of cadmium (Cd) in blood (0.11 +/- 0.01 ppm) and milk (0.05 +/- 0.01 ppm). These values were considerably higher than those for rural cattle in India. The findings indicated varying degrees of exposure of animals to Pb and Cd in the vicinity of the smelter.     

DNA (cytosine) methyltransferase overexpression is associated with acquired drug resistance of murine neuroblastoma cells

We have previously reported that C-1300 murine neuroblastoma (rMNB) cells made resistant to the nucleoside analogue, (Z)-5'-fluoro-4', 5'-didehydro-5'deoxyadenosine (MDL), an irreversible inhibitor of S-adenosylhomocysteine (AdoHcy) hydrolase have an increased expression of the S-adenosylmethionine (AdoMet) synthetase gene. Results of the immunoblot analysis of DNA (cytosine) methyltransferase with anti-human DNA (cytosine) methyltransferase specific polyclonal antibody demonstrated a significant increase ( approximately 2-fold, p<0.01) in expression of DNA (cytosine) methyltransferase protein in rMNB/MDL cells compared to wild-type C1300 MNB (wMNB) cells. To rule out the possibility that multidrug resistance (MDR) genes are involved in development of acquired drug resistance in murine neuroblastoma (rMNB/MDL) cells made resistant to MDL, the expression of Mdr1a, Mdr1b, Mdr2 (multidrug resistance/P-glycoprotein), and Mrp-1 (multidrug resistance associated protein) was examined in rMNB-MDL cells. The analysis of Mdr and Mrp-1 expression was performed by RT-PCR using PCR specific primers to respective genes. No significant difference was observed in the expression of MDR1a, Mdr1b and Mrp-1 genes between wMNB and rMNB-MDL cells, however, a slight decrease was noticed in Mdr1 expression in some samples. Expression of the Mdr2 (human MDR3) gene, which is not associated with the acquired drug resistance phenotype, was significantly decreased in rMNB-MDL cells. These findings were also confirmed by the immunoblot analyses using specific monoclonal antibodies to Mdr1/3 proteins. Expression of N-Myc gene--a prognostic factor in neuroblastoma tumors was also not altered in rMNB-MDL cells. Results of the present study suggest that acquired drug resistance in rMNB-MDL cells to MDL is associated to the overexpression of DNA (cytosine) methyltransferase, and could be due to genetic or epigenetic changes in particular to DNA hypermethylation in response to an increased AdoMet synthetase gene expression.     

Effect of thiamine hydrochloride on lead induced lipid peroxidation in rat liver and kidney

Thiamine hydrochloride was studied on lead-induced endogenous lipid peroxidation in rat hepatic and renal tissues following po doses of 2.73 mg lead/kg bw for 6 w. Simultaneous use of 25 mg thiamine hydrochloride/kg bw po reduced lead accumulation in liver and kidneys. There were significant decreases in endogenous lipid peroxide in liver and kidney from thiamine hydrochloride-treated rats. Histopathological lesions in thiamine-treated livers and kidneys were milder in comparison to lesions in untreated Pb-exposed animals. This indicates the prophylactic potential of thiamine for lead-induced lipid peroxidation.     

Picroliv affords protection against thioacetamide-induced hepatic damage in rats

Thioacetamide (100 mg/kg), when administered to normal rats, caused a significant increase in the activities of 5'-nucleotidase and gamma-glutamyl transpeptidase and a decrease in the activities of glucose 6-phosphatase and succinate dehydrogenase enzymes in the liver. DNA, RNA, and proteins were increased while the cytochrome P450 in the microsomal fraction and the glycogen content in the liver were decreased significantly. Elevations in the activities of GOT, GPT, and alkaline phosphatase and bilirubin content in serum were also observed. Picroliv, a standardised glycoside fraction of Picrorhiza kurroa, in doses of 12.5 and 25 mg/kg prevented most of the biochemical changes induced by thioacetamide in liver and serum. The hepatoprotective activity of Picroliv was comparable with that of silymarin, a known hepatoprotective agent obtained from seeds of Silybum marianum.     

Evaluation of speech outcomes following treatment of oral and oropharyngeal cancers

Oral and oropharyngeal cancers are amongst the commonest cancers worldwide and present a major health problem. Owing to their critical anatomical location and complex physiologic functions, the treatment of oral and oropharyngeal cancers often affects important functions, including speech. The importance of speech in a patient’s life can not be overemphasized, as its loss is often associated with severe functional and psychosocial problems and a poor quality of life. A thorough understanding of the speech problems that are faced by these patients and their timely management is the key to providing a better functional quality of life, which must be one of the major goals of modern oncologic practice. This review summarises key methods of evaluation and outcome of speech functions in the literature on oral and oropharyngeal cancer published between January 2000 and December 2008. Speech has been generally overlooked and poorly investigated in this group of patients. This review is an attempt to fill this gap by conducting the first speech-specific review for oral and oropharyngeal cancer patients. We have proposed guidelines for better understanding and management of speech problems faced by these patients in their day-to-day life.