Advanced oxidation protein products and total antioxidant activity in colorectal carcinoma.

The present study was designed to assess the levels of advanced oxidation protein products (AOPP) and percent hemolysis (that indirectly indicates the degree of membrane damage secondary to lipid peroxidation) in colorectal carcinoma. Glutathione (GSH), total thiols and albumin were measured to determine the antioxidant status. Considering the dynamic interaction between various antioxidants in the body, we measured the total antioxidant activity (AOA). Globulin was measured to assess the inflammatory response secondary to oxidative stress. Investigations were conducted in 45 cases of recently diagnosed primary colorectal adenocarcinoma. As control, 45 age and sex matched healthy persons were chosen. GSH was estimated in whole blood, percent hemolysis in RBC suspension and other parameters in plasma. We observed a very high significant increase (P<0.001) in AOPP, percent hemolysis and a highly significant increase (P<0.01) in globulin in colorectal carcinoma. We observed a very high significant decrease (P<0.001) in whole blood GSH, total thiols, albumin, AOA and a significant decrease (P<0.05) in plasma GSH in colorectal carcinoma. A very high significant negative correlation between percent hemolysis and AOA and an apparent negative correlation between total thiols and AOPP was seen in colorectal carcinoma. This demonstrated oxidative stress, decreased antioxidant status and secondary inflammatory response in colorectal carcinoma.

Oxidative stress and low dose ionizing radiation.

The field of radiation biochemistry has provided tremendous impact in recent years as extensive research on free radicals has implicated them in radiation damage. An important offshoot of this field is the branch dealing with radiological protection in medical applications like diagnostic radiology. Hence, we decided to investigate the relationship between oxidative stress and low dose ionizing radiation (x-rays) in the work environment of x-ray technicians (radiographers), by comparing their RBC malondialdehyde, % hemolysis, catalase and plasma vitamin E levels with those of controls. There was a significant increase in the susceptibility of RBCs to hemolysis in radiographers compared to controls. Malondialdehyde and catalase levels were slightly increased in the radiographers, but this did not disturb the steady state concentration of their plasma vitamin E. These findings go in favour of theories stating that exposure to low dose ionizing radiation does cause a greater amount of oxidative stress, than that caused during normal routine metabolic processes.

Effect of extract of Benincasa hispida on oxidative stress in rats with indomethacin induced gastric ulcers.

This study was undertaken to determine the healing of ulcers induced by indomethacin due to antioxidant role of fruit extract of Benincasa hispida (Ashgourd) on ulcers in rats. Malondialdehyde (MDA) in RBC and antral homogenate was determined to measure tissue oxidation. Superoxide dismutase (SOD) in RBC and antral homogenate, plasma and homogenate vitamin C were estimated as measures of antioxidant defense. On induction of gastric ulcer, there was significant increase in SOD in RBC and homogenate levels and vitamin C in plasma. There was an apparent decrease in ulcer index in animals treated with fruit extract. There was significant decrease in MDA with concomitant decrease in SOD and vitamin C levels in the treated rats when compared to those not treated with fruit extract. Benincasa hispida has been shown to contain certain active principles like terpenes, flavanoid C--glycosides and sterols which have antioxidant effects. These probably inhibit gastric mucosal injury by scavenging the free radicals and repress production of SOD and vitamin C in these rats.

Possible role of Granulocyte Macrophage Colony Stimulating Factor receptor (GM-CSF R) in malaria.

Malaria has been reportedly increasing in incidence on the globe. Evidence from clinical studies supports a role for cytokines in the pathogenesis of cerebral malaria. Given the stimulatory effect of the ligand GM-CSF on the synthesis and release of the pyrogenic cytokine TNF alpha, the present study has been undertaken to investigate a possible role of GMCSF receptor in the pathogenesis of both Plasmodium vivax and Plasmodium falciparum malaria. An enzyme immunoassay developed by us at our laboratory for the quantitation of GM-CSF receptor has been used. No changes in the concentration of the receptor have been indicated either at the time of diagnosis or after treatment. In addition, an intercomparison of the receptor concentration between the P. vivax and P. falciparum groups does not show any significant difference. The results suggest that GM-CSF receptor has no significant role in the pathogenesis of either type of malaria.