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Biomedical subjects

C R Ramachandran

Publications and source records attributed to C R Ramachandran.

At least 19 recordsLinked to original sources
PubMed2004

Analysis of glycoconjugates in patients with oral squamous cell carcinoma.

BACKGROUND: Our aim was to examine the levels of glycoconjugates in plasma, erythrocyte membranes and buccal mucosa of healthy subjects and oral cancer patients. SUBJECTS AND METHODS: This study was conducted on 48 adult male oral cancer patients with various clinical stages (stage II to stage IV; 16 of each) and 16 disease-free healthy subjects who underwent surgical removal of impacted teeth or vestibuloplasty without inflammation. RESULTS: The plasma and tumor tissues glycoconjugates levels were significantly increased, whereas the erythrocyte membranes glycoconjugates were significantly decreased in oral cancer patients as compared to healthy subjects. The levels of glycoconjugates were gradually increased from stage II to stage IV in plasma and tumor tissues and decreased in erythrocyte membranes from stage II to stage IV of oral cancer patients. CONCLUSION: The increased plasma glycoconjugates can be due to the expense of erythrocyte membrane glycoconjugates or tumor tissue itself.

Adult↗
PubMed2003

Biochemical changes in tumor tissues of oral cancer patients.

OBJECTIVES: Our aim was to assess the oxidative stress in tumor tissues of oral cancer patients by measuring the levels of lipids, thiobarbituric acid reactive substances (TBARS) and antioxidants. DESIGN AND METHODS: This study has been conducted on oral tumor tissues of 48 adult male oral cancer patients with various clinical stages (stage II to stage IV; 16 of each) and normal tissues of an equal number of age and sex matched disease free healthy subjects. The levels of lipids, lipid peroxidation and antioxidants in buccal mucosa of healthy subjects and oral cancer patients were assayed using colorimetric methods, except for vitamin E (fluorometriy). RESULTS: Total cholesterol and esterified cholesterol were markedly increased whereas phospholipids and free fatty acids were significantly decreased in tumor tissues as compared to normal tissues. The decrease in TBARS levels and functional compromise of antioxidant defense mechanisms were observed in the tumor tissues as compared to normal subjects. CONCLUSIONS: The low availability of peroxidizable substrates and the enhanced antioxidant capacity in tumor tissues make them less susceptible to oxidative stress, conferring a selective growth advantage on tumor cells.

Antioxidants↗
PubMed2002

Oxidant-antioxidant status in patients with oral squamous cell carcinomas at different intraoral sites.

OBJECTIVES: To compare the extent of lipid peroxidation and the status of antioxidants in tumor and venous blood of patients with oral squamous cell carcinoma (OSCC) at different intraoral sites. DESIGN AND METHODS: Twenty four patients with OSCC at different intraoral sites and an equal number of age- and sex-matched reference subjects were chosen for the study. The concentrations of lipid peroxides and reduced glutathione (GSH) and the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were estimated in tissues and blood. RESULTS: Diminished lipid peroxidation in tumor tissue was accompanied by decreased activities of SOD and CAT with increase in GSH and GSH-dependent enzymes. In contrast, enhanced lipid peroxidation with decrease in antioxidants was observed in the venous blood of OSCC patients. CONCLUSION: No significant differences in lipid peroxidation and antioxidant levels were observed between patients with OSCC at different intraoral sites. However, our results revealed differences between the tumor and blood with respect to their susceptibility to lipid peroxidation and antioxidant status.

Adult↗
PubMed2001

Prevention of 4-nitroquinoline 1-oxide-induced rat tongue carcinogenesis by garlic.

The present study was undertaken to examine the inhibitory effect of garlic (Allium sativum) on 4-nitroquinoline 1-oxide (4NQO)-induced tongue carcinogenesis in male rats, both in the initiation and post-initiation phases. Lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were used to monitor the chemopreventive potential of garlic. Biochemical estimations were carried out on tumour and normal tongue tissues. Diminished lipid peroxidation in the tumour tissue was accompanied by a significant increase in the levels of GSH, GPx and GST. Administration of garlic (250 mg/kg, p.o., three times a week) effectively suppressed 4NQO-induced tongue carcinogenesis as revealed by the absence of carcinomas in the initiation phase and their reduced incidence in the post-initiation phase. The results of the present study suggest that garlic may exert its chemopreventive effects by modulating lipid peroxidation and enhancing the levels of GSH, GPx and GST.

4-Nitroquinoline-1-oxide↗
PubMed2001

Chemopreventive efficacy of lycopene on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

The chemopreventive efficacy of lycopene on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis was examined using lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) as biomarkers of chemoprevention. Twenty four male Syrian hamsters were divided into four groups of six animals each. The right buccal pouches of the animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin three times a week. The animals in group 2 were painted with DMBA as in group 1 and in addition received 2.5 mg/kg body weight lycopene orally three times a week on days alternate to DMBA application. Group 3 animals received lycopene as in group 2. Animals in group 4 received neither DMBA nor lycopene and served as control. The hamsters were killed after an experimental period of 14 weeks. Biochemical measurements were carried out in tumour and normal tissues. All hamsters painted with DMBA alone for 14 weeks developed well-differentiated squamous cell carcinomas. Diminished lipid peroxidation in the oral tumour tissue was accompanied by a significant increase in the levels of GSH, GPx, GST and GR. Administration of lycopene significantly suppressed DMBA-induced oral carcinogenesis as revealed by the absence of carcinomas. The results of the present study suggest that lycopene may exert its chemopreventive effects by modulating lipid peroxidation and enhancing the activities of the enzymes in the glutathione redox cycle.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

Coffee enhances the development of 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinomas.

UNLABELLED: In this study, we examined the effect of roasted coffee extract on 7,12-dimethylbenz[a]anthracene (DMBA)-induced buccal pouch carcinogenesis in male Syrian hamsters using lipid peroxidation, reduced glutathione (GSH) and glutathione peroxidase (GPx) activity as biomarkers of chemoprevention. Forty male hamsters were divided into four groups of 10 animals. The right buccal pouches of the animals in Group 1 was painted with a 0.5% solution of DMBA in liquid paraffin three times a week. The animals in Group 2 painted with DMBA as in Group 1, received in addition 2 ml of 8% black coffee extract intragastrically three times a week on days alternate to DMBA application. Group 3 animals received coffee extract as in Group 2. Animals in Group 4 received neither DMBA nor coffee extract and served as control. The hamsters were sacrificed after an experimental period of 14 weeks. Biochemical measurements were carried out on tumour and normal pouch tissues. Administration of roasted coffee extract had no preventive effect on DMBA-induced oral cancer as revealed by the higher mean tumour volume and tumour burden compared to animals painted with DMBA alone. Diminished lipid peroxidation in the oral tumour tissue was accompanied by a significant increase in the levels of GSH and GPx. CONCLUSIONS: The results of the present study suggest that coffee exerts a tumour enhancing effect when administered during DMBA-induced hamster buccal pouch carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

S-allylcysteine, a garlic constituent, inhibits 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

The effect of S-allylcysteine (SAC), a water-soluble garlic constituent, on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis was investigated in male Syrian hamstes. Forty hamsters were divided into 4 groups of 10 animals. The right buccal pouches of the animals in Group I were painted with a 0.5% solution of DMBA in liquid paraffin three times a week. The animals in Group II were painted with DMBA as in Group I and, in addition, received 200 mg/kg body wt p.o. SAC three times a week on days alternate to DMBA application. Group III animals received SAC as in Group II. Group IV animals received neither DMBA nor SAC and served as the control. The hamsters were killed after an experimental period of 14 wk. Measurement of lipid peroxidation, the antioxidant enzymes superoxide dismutase (SOD) and catalase, in the buccal pouch mucosa, liver, and circulation was used to monitor the chemopreventive potential of SAC. All hamsters painted with DMBA alone developed tumors identified histologically as well-differentiated squamous cell carcinomas. In hamsters bearing DMBA-induced buccal pouch tumors, diminished lipid peroxidation in the tumor tissue was accompanied by decreased activities of SOD and catalase, whereas in the liver and circulation, enhanced lipid peroxidation was associated with compromised antioxidant defenses. Administration of SAC suppressed the incidence of DMBA-induced HBP tumors as revealed by the absence of carcinomas. Histologically, only keratosis was observed. SAC modulated DMBA-induced decreased susceptibility of the HBP to lipid peroxidation while simultaneously enhancing SOD and catalase activities, whereas in the liver and circulation, SAC decreased the extent of lipid peroxidation and significantly enhanced antioxidant activities. We suggest that SAC exerts its chemopreventive effects by modulating lipid peroxidation and enhancing antioxidant activities in the target organ as well as in the liver and circulation.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

Of humans and hamsters: comparative analysis of lipid peroxidation, glutathione, and glutathione-dependent enzymes during oral carcinogenesis.

We examined the extent of lipid peroxidation and the amount of reduced glutathione (GSH), and activities of the GSH-dependent enzymes, glutathione peroxidase (GPx) and glutathione S-transferase (GST), in human oral tumour tissue and 7, 12-dimethylbenz[a]anthracene-(DMBA)-induced hamster buccal pouch tumour tissues. Diminished lipid peroxidation in the oral and hamster tumours was accompanied by a significant reduction in the concentration of phospholipids and an increase in the cholesterol:phospholipid ratio. The concentration of glutathione and the activities of GPx and GST were raised in both human oral and hamster tumour tissues. Our results show that the patterns of changes in human oral squamous cell carcinomas and chemically-induced carcinomas of the hamster buccal pouch are similar.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Chemopreventive potential of neem (Azadirachta indica) on 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinogenesis.

The inhibitory effect of the aqueous extract of neem (Azadirachta indica A. Juss.) on 7,12-dimethylbenz[a]anthracene (DMBA) induced buccal pouch carcinogenesis was investigated in Syrian male hamsters. All hamsters painted on their buccal pouch with DMBA for 14 weeks developed squamous cell carcinoma. Administration of neem leaf extract effectively suppressed oral carcinogenesis initiated with DMBA as revealed by the reduced incidence of neoplasms. Lipid peroxidation, glutathione (GSH) content and the activities of glutathione peroxidase (GPx), glutathione S-transferase (GST) and gammaglutamyl transpeptidase (GGT) were used to biomonitor the chemopreventive potential of neem. Lipid peroxidation was found to be significantly decreased, whereas GSH, GPx, GST and GGT were elevated in the oral mucosa of tumour bearing animals. Our data suggest that neem may exert its chemopreventive effects in the oral mucosa by modulation of lipid peroxidation, antioxidants and detoxification systems.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Effects of garlic on 7,12-Dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis.

The inhibitory effect of garlic (Allium sativum Linn) on 7, 12-dimethylbenz[a]anthracene (DMBA)-induced buccal pouch carcinogenesis was investigated in male Syrian hamsters. Measurement of lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), and glutathione S-transferase (GST) was used to monitor the chemopreventive potential of garlic. All hamsters painted on their buccal pouches with DMBA alone for 14 weeks developed well-differentiated squamous cell carcinomas. Diminished lipid peroxidation in the oral tumor tissue was accompanied by a significant increase in the levels of GSH, GPx, and GST. Administration of 250 mg/kg body weight aqueous garlic extract three times a week for 14 weeks effectively suppressed DMBA-induced oral carcinogenesis as revealed by the reduced incidence of neoplasms. The results of the present study suggest that garlic may exert its chemopreventive effects by modulating lipid peroxidation and enhancing the levels of GSH, GPx, and GST.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

Fine needle aspiration cytology as a diagnostic test for oral squamous cell carcinoma.

OBJECTIVE: The purpose of this study was to determine the possibility of using fine needle aspiration cytology (FNAC) as a primary diagnostic test in oral leukoplakia and squamous cell carcinoma. MATERIALS AND METHODS: The sample consisted of 12 cases of oral leukoplakia and 60 cases of oral squamous cell carcinoma. FNAC and biopsy was done on all cases. A cytological and histopathological correlation was undertaken to determine the proportion of cancers that can be accurately diagnosed by FNAC and its ability to identify differentiation gradings of squamous cell carcinomas. A blind examination was undertaken. RESULTS: In oral leukoplakias equal rates of true positive and false negative results were obtained. The overall positive correlation accounted for 33.33% with 33.33% inadequate FNACs. In oral squamous cell carcinomas 92.85% of true positive and 7.14% of false negative results were obtained. The differentiation gradings correlated in only 41.07%. The overall positive correlation was 86.66% with 6.66% inadequate FNACs. CONCLUSIONS: The present study indicates that FNAC can be used as a reliable diagnostic test for oral squamous cell carcinoma but its use in oral leukoplakia is of limited value.

Adult↗
PubMed1994

Health consequences of vasectomy in India.

Vasectomy acceptance has been declining in India during the past 20 years. Even if the risk of prostate cancer is marginally higher in vasectomized men, this risk in India has to be assessed against the immediate safety and other possible long-term benefits of this procedure. The Indian Council of Medical Research has launched a case-control study, which is unlikely to be time-consuming or beyond the available means and resources, in order to obtain definitive data on this problem. Meanwhile, vasectomy remains an excellent procedure for the couple seeking permanent methods of contraception, and specific efforts to promote its acceptance must continue in India.

Case-Control Studies↗