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Biomedical subjects

S Manoharan

Publications and source records attributed to S Manoharan.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of anticarcinogenic effects of Clerodendron inerme on 7,12-dimethylbenz(a) anthracene-induced hamster buccal pouch carcinogenesis.

INTRODUCTION: Oral cancer is the fifth most frequent cancer worldwide and India has recorded the highest incidence (40-50 percent) of oral malignancy. Clerodendron inerme is used by Indian traditional practitioners for the treatment of various ailments, including cancer. Our aim was to investigate the chemopreventive potential of the aqueous leaf extract of Clerodendron inerme (CiAet) in 7,12-dimethylbenz(a) anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. METHODS: We developed oral squamous cell carcinoma in the buccal pouch of male Syrian golden hamsters by painting them with 0.5% DMBA in liquid paraffin thrice a week for 14 weeks. The tumour incidence, tumour volume and tumour burden that were formed in the hamster buccal pouches were determined. RESULTS: Oral administration of CiAet at a dose of 500 mg/kg body weight to DMBA-painted animals on days alternate to DMBA painting for 14 weeks significantly prevented the tumour incidence, tumour volume and tumour burden. CiAet also exerts potent antilipidperoxidative effect and improved the antioxidant defence system in DMBA-painted animals. The chemopreventive efficacy of CiAet was evident by inhibition of tumour formation (80%) in DMBA-painted animals. CONCLUSION: The chemopreventive potential of CiAet is probably due to its antilipidperoxidative effect or the presence of some potent bioactive chemopreventive principles in the leaves of Clerodendron inerme.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2005

Antihyperglycemic and antilipidperoxidative effects of Pongamia pinnata (Linn.) Pierre flowers in alloxan induced diabetic rats.

Our aim was to evaluate the antihyperglycemic and antilipid peroxidative effect of ethanolic extract of Pongamia pinnata (Linn.) Pierre (Leguminosae) flowers (PpEt) in normal rats and alloxan induced diabetic rats. Hyperglycemia, elevated lipid peroxidation [thiobarbituric acid reactive substances (TBARS)] and disturbed nonenzymatic [Vitamin E, Vitamin C and glutathione] and enzymatic antioxidants status were noticed in alloxan induced diabetic rats. The oral administration of ethanolic extract of Pongamia pinnata flowers (300 mg/kg bw) showed significant antihyperglycemic, and antilipidperoxidative effects and enhancement in antioxidants defense system in alloxan induced diabetic rats. However, no significant characteristic changes were noticed in blood glucose level as well as in lipid peroxidation and antioxidant status in normal rats treated with "PpEt" alone. We have also observed that the "PpEt" considerably reduced the blood glucose concentration in a similar extent to that of the reference drug glibenclamide (600 microg/kg bw) in alloxan induced diabetic rats. Our results thus suggested that the "PpEt" could be used as a safe alternative antihyperglycemic drug for diabetic patients.

Alloxan↗
PubMed2005

Melatonin modulates the oxidant-antioxidant imbalance during N-nitrosodiethylamine induced hepatocarcinogenesis in rats.

PURPOSE: Melatonin, the principle hormone of pineal gland plays an important role in several biological processes. The effects of melatonin on hepatic marker enzymes [aspartate and alanine transaminases (AST and ALT)], lipid peroxides [thiobarbituric acid reactive substances (TBARS)] and antioxidants [reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)] during N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis in rats were studied. METHODS: Male albino Wistar rats of body weight 150-170 g were divided into four groups of six animals each. Group I animals served as control, Group II animals received single intraperitoneal injection of NDEA at a dose of 200 mg/kg body weight followed by weekly subcutaneous injections of CCl4 at a dose of 3 mL/kg body weight. Group III animals were treated as in Group II and melatonin (5 mg/kg body weight) was administered intraperitoneally. Group IV animals received melatonin alone at the same dose as Group III animals. RESULTS: A significant increase in the activities of serum AST and ALT was observed in NDEA treated rats when compared with control animals. Melatonin administered rats showed a significant decrease in the activities of these enzymes when compared with NDEA treated animals. In the liver of NDEA-treated animals, decreased lipid peroxidation associated with enhanced antioxidant levels was observed. Administration of melatonin positively modulated these changes. CONCLUSION: Our results indicate that melatonin exerts chemopreventive effect by restoring the activities of hepatic marker enzymes and reversing the oxidant-antioxidant imbalance during NDEA-induced hepatocarcinogenesis.

Animals↗
PubMed2005

Repeat survey of current practice regarding corticosteroid prophylaxis for patients at increased risk of adverse reaction to intravascular contrast agents.

AIM: To compare the findings of a survey undertaken by us in 2002 regarding steroid premedication given in radiology departments to reduce the risk of adverse reactions in patients at increased risk of intravascular contrast media reactions with a similar survey published in 1994 by R. Seymour et al. The high risk patients considered in our survey were patients with history of asthma, drug allergies, hay fever and eczema. MATERIALS AND METHODS: A total of 225 questionnaires were sent to the consultant in charge for audit for radiology departments from the list given by the Royal College of Radiologists. 175 of the 225 questionnaires were returned (response rate 77.8%) and of these 172 were analysed with respect to the type, dose and duration of steroids. RESULTS: Compared to the survey in 1994, it was found that the number of departments who use steroid cover for all category of risk factors had increased compared to previous survey (73.8% in 2002 versus 55.3% in 1994 (p=0.001). There is now almost universal use of non-ionic contrast 98.8% versus 82.4% in 1994 (p=0.001). There is no agreed policy among radiology departments for the need or the dose or duration of steroid cover. CONCLUSION: Despite the more widespread use of non-ionic contrast media, the use of steroid premedication has increased which is contrary to what is expected as the incidence of adverse reaction to non ionic media is less than ionic contrast media.

Consultants↗
PubMed2005

Chemopreventive efficacy and anti-lipid peroxidative potential of Jasminum grandiflorum Linn. on 7,12-dimethylbenz(a)anthracene-induced rat mammary carcinogenesis.

The aim of this study was to investigate the chemopreventive efficacy and anti-lipid peroxidative potential of Jasminum grandiflorum Linn. on 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary carcinogenesis. Mammary tumors were developed by a single subcutaneous injection of 25 mg DMBA in 1 mL emulsion of sunflower oil and physiological saline. The tumor incidence and tumor volume that formed in the breast were determined. Oral administration of ethanolic extract of J. grandiflorum flowers (JgEt) at a dose of 300 mg/kg body weight for 14 weeks to DMBA-injected animals completely prevented the formation of tumors in the pre-initiation period. JgEt also exerted significant anti-lipid peroxidative effect and improved the antioxidant defense system in DMBA-treated rats. The results of this study clearly indicate that JgEt has potent chemopreventive efficacy in experimental mammary carcinogenesis and further studies are warranted to isolate and characterize the bioactive principle from JgEt.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2005

Circadian rhythmicity of plasma lipid peroxidation and antioxidants in oral squamous cell carcinoma.

INTRODUCTION: Oral cancer is one of the leading cancers in India accounting for 30 to 40 percent of all cancers. Disturbances in lipid peroxidation and antioxidants status have been implicated in the pathogenesis of several cancers including oral cancer. However, circadian disturbances of oxidants and antioxidants in oral cancer patients were not reported. METHODS: The levels of plasma thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and activity of glutathione peroxidase (GPx) in ten oral cancer patients and an equal number of age-matched healthy subjects were assayed at every 6 hour intervals using colorimetric methods and their circadian characteristics were analysed using Cosinorwin computer software programme. RESULTS: Alterations in mesor, amplitude, acrophase and r value of the chosen parameters were noticed. DISCUSSION: The desynchronisation of plasma thiobarbituric acid reactive substances and the altered circadian characteristics of antioxidants observed in this study, may deserve further investigation for the early diagnosis, prognosis and for the efficacy of cancer chronotherapy.

Carcinoma, Squamous Cell↗
PubMed2005

Nucleotide sequence analysis of the L1 loop variable region of hexon gene of fowl adenovirus 4 isolates from India.

Three fowl adenovirus 4 (FAV4) isolates from chicken and one from quail, all from Tamil Nadu, India were analyzed. The L1 loop variable region of hexon gene of these isolates was amplified by PCR and sequenced. The nucleotide sequences (442 bp) and deduced amino acid sequences of the four isolates were compared with those of other isolates of FAV4. The nucleotide sequences of the four isolates had a 98% homology with other Indian isolates and a 96% homology with Belgian and Russian isolates. The amino acid sequences of the four Indian isolates had a more than 98% homology with other Indian isolates and a more than 92% homology with Belgian and Russian isolates. Hence, the variable of L1 loop region of hexon gene was found to be highly homologous in all the FAV4 isolates tested both at nucleotide and amino acid level.

Adenoviridae Infections↗
PubMed2005

Diurnal rhythmicity of thiobarbituric acid reactive substances and antioxidants in experimental mammary carcinogenesis.

AIM: Circadian rhythms of reactive oxygen species and antioxidants have been the subject of considerable interest in recent years due to their crucial role in the development of malignant tumors. Our aim was to analyze the circadian pattern of lipid peroxidation by-products (TBARS) and antioxidants status in 7,12-dimethylbenz(a)anthracene (DMBA) induced rat mammary carcinogenesis. METHODS: Mammary tumors were developed in Wistar rats, blood samples were collected at a regular interval of 4 h throughout the 24 h period and TBARS content and antioxidant enzymes activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)) were estimated by colorimetric methods. The Cosinorwin computer software program was used to analyze the characteristics of biochemical rhythms. RESULTS: In mammary carcinogenesis, the acrophase of thiobarbituric acid reactive substances and antioxidant enzymes (SOD, CAT, GPx) in blood were found to be delayed, whilst mesor values for TBARS level - increased, and values for SOD, CAT, GPx activities - decreased. Significant r-values indicate the disruption of lipid peroxidation-antioxidants rhythms in mammary carcinogenesis. CONCLUSION: The present investigation suggests that the circadian pattern of blood lipid peroxidation and antioxidants in rats with mammary carcinoma are markedly desynchronized as compared to normal rats.

Animals↗
PubMed2005

Lipid peroxidation & antioxidants status in patients with oral squamous cell carcinoma.

BACKGROUND & OBJECTIVE: Overproduction of lipid peroxidation byproducts and disturbances in antioxidant defense system have been implicated in the pathogenesis of several diseases including oral cancer. Though several studies have been done on the level of lipid peroxidation and antioxidants in oral cancer patients, there are no reports in patients with various clinical stages of oral squamous cell carcinoma. We carried out this study to assess the level of oxidative stress in oral cancer patients with various clinical stages. METHODS: Blood samples of 48 adult male oral cancer patients with various clinical stages of oral cancer (stage II to stage IV, 16 of each) and 16 age and sex matched healthy subjects were collected. Plasma and erythrocytes levels of thiobarbituric acid reactive substances (TBARS), vitamin E, reduced glutathione (GSH), and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were assayed using specific colorimetric methods. The statistical comparisons were performed by one way analysis of variance (ANOVA) followed by Student's t-test. RESULTS: Elevated lipid peroxidation and decline in non-enzymatic and enzymatic antioxidants status were noticed in oral cancer patients as compared to healthy subjects. The TBARS levels were gradually increased whereas antioxidants were gradually reduced from stage II to stage IV of oral cancer patients. INTERPRETATION & CONCLUSION: The altered lipid peroxidation in plasma and erythrocytes of oral cancer patients may be related to their compensatory changes in the antioxidants defense system.

Adult↗
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↗
PubMed2004

Rapid serological profiling by an immunocomb-based dot-enzyme-linked immunosorbent test for three major poultry diseases.

An immunocomb-based dot-ELISA, employing specially designed apparatus, was used to measure the antibody status for the three major poultry diseases--Newcastle disease, infectious bursal disease and infectious bronchitis--in single test sera. Positive samples could be classified into strong, moderate and weak positives by comparison with the colour reaction given by known strong and weak positive serum controls. The simultaneous dot-immunobinding assay gave reproducible results and allowed considerable savings on the cost of reagents compared to liquid ELISA. The antigen-coated immunocomb can be stored under refrigeration and the test can be performed rapidly under field conditions by trained personnel.

Animals↗
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

Measurement of erythrocyte lipids, lipid peroxidation, antioxidants and osmotic fragility in cervical cancer patients.

BACKGROUND: Our aim was to examine the structural integrity of red blood cells in cervical cancer patients by measuring the concentrations of thiobarbituric acid reactive substances (TBARS), antioxidant status, cholesterol/phospholipid (C/P) molar ratio, enzyme activity and osmotic fragility of erythrocytes. METHODS: This study has been conducted on 32 adult female cervical cancer patients and an equal number of age- and sex-matched normal subjects. Erythrocyte concentrations of lipids, TBARS, vitamin E, reduced glutathione and enzymic activities of catalase and Na(+)K(+)-ATPase were measured as well as plasma concentrations of sodium and potassium. The present study also examined the changes in erythrocyte osmotic fragility in cervical cancer patients and normal subjects. The red cell fluidity and permeability were determined by estimating the C/P ratio and Na(+)K(+)-ATPase activity, respectively. RESULTS: The release of thiobarbituric acid reactive substances was significantly higher in cervical cancer patients as compared to normal subjects. The increased lipid peroxidation with concomitant decrease in antioxidants was notable in cervical cancer patients. Red blood cells of cervical cancer patients were more fragile than those from normal subjects. Increase in red cell membrane C/P ratio and Na(+)K(+)-ATPase activity was noticed in cervical cancer patients as compared to normal subjects. CONCLUSIONS: Increased lipid peroxidation, insufficient antioxidant potential and changes in C/P molar ratio as well as activity of Na(+)K(+)-ATPase cause structural and functional abnormalities in the erythrocytes of cervical cancer patients.

Adult↗
PubMed2002

Lipid peroxidation and antioxidant status in cervical cancer patients.

The present study examined the relationship between lipid peroxidation and antioxidant status in plasma, erythrocyte and erythrocyte membrane of cervical cancer patients and an equal number of age and sex matched normal subjects as well as patients with cervicitis. Lipid peroxidation was significantly increased with concomitant decrease in antioxidant levels in cervical cancer patients as compared to normal subjects and patients with cervicitis. The elevated lipid peroxidation and disturbed antioxidant status was also noticed in cervicitis patients as compared to normal subjects. This increase in lipid peroxidation can be attributed to possible breakdown of antioxidant mechanisms in cervicitis and cervical cancer patients.

Adult↗
PubMed1997

Role of life-style on plasma and erythrocyte membrane lipid profile in gastric cancer patients.

The present study has examined the role of life-style on plasma and erythrocyte membrane lipid profile in 25 adult male gastric cancer patients as well as age and sex-matched controls. Total, free and LDH cholesterol were markedly elevated in plasma and erythrocyte membrane whereas HDL cholesterol and triglycerides were significantly reduced in gastric cancer patients. These changes can be attributed to alcohol consumption and cigarette smoking-risk factors in gastric carcinogenesis, associated with low levels of ascorbic acid and vitamin E.

Adenocarcinoma↗
PubMed1989

Clinical, haemodynamic and echocardiographic study in chronic cor pulmonale.

Thirty patients of chronic cor pulmonale were studied clinically and by chest skiagram, electrocardiography, echocardiography, pulmonary function tests, arterial blood gas analysis and, wherever possible by right heart catheterization. Pulmonary arterial pressures (PAP) correlated significantly only with cardiomegaly on skiagram and with arterial oxygen tension (PaO2). There was no significant correlation between mean PA pressures and prominent pulmonary conus on RVH by ECG, FEV1, PaCO2 or right ventricular outflow tract dimensions by echocardiography. Left ventricular function, as assessed by pulmonary capillary wedge pressure on cardiac catheterization, by LV ejection fraction and fractional shortening on echocardiography was normal in all cases except two (6.67%). There was significant increase in left ventricular posterior wall thickness in the patients studied.

Adult↗