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Biomedical subjects

A Parthasarathy

Publications and source records attributed to A Parthasarathy.

10 recordsLinked to original sources

Controversies in BCG immunization.

Despite controversies BCG vaccination has stood the test of time. World Health Organization continues to recommend its use in infant immunization programme in countries with heavy endemicity and where threatening HIV epidemic in an emerging problem > 85% efficacy have been established in recent years against hematogenous spread of the disease and > or = 50% efficacy even against pulmonary tuberculosis. Host related factors, agent related factors, vaccine related factors and inadequacy of evaluation tests determine the BCG vaccine efficacy. Identification of complete BCG genome in 1998 has opened new vistas in newer BCG vaccine development. Adoption of a '5C' concept viz. Case detection, Chemotherapy short course, Contact elimination, Chemoprophylaxis and lastly control in BCG vaccine will be a desirable national approach in combating adult and childhood TB.

BCG Vaccine↗

Oxidative DNA damage in the aging mouse brain.

The brain exhibits regional vulnerabilities to many insults, and age itself has differential effects on neuronal populations as exemplified by the age-dependent loss of dopaminergic neurons in the nigrostriatal system. We hypothesized that oxidative damage to DNA was more likely to occur in the nigrostriatal system which undergoes significant neurochemical and functional changes with age. To test this hypothesis, oxidative damage to DNA, indicated by levels of 8-hydroxy2'-deoxyguanosine (oxo8dG), was measured in pons-medulla (PM), midbrain (MB), caudate-putamen (CP), hippocampus (HP), cerebellum (CB), and cerebral cortex (CX) at 3, 18, and 34 months of age in C57/b1 mice. Steady-state levels of oxo8dG increased significantly with age in MB, CP, and CB, but not in PM, HP, or CX. Manganese superoxide dismutase (MnSOD) activity decreased with age in MB, CP, and HP, but not in PM, CB, or CX. Regional activities of Cu/Zn superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase (Glut Px) did not change significantly with age. Concomitant with the regional alterations in DNA damage, there was a significant age-dependent decline in locomotor activity, motor coordination, and striatal dopamine content especially during the interval between 18 and 34 months. In conclusion, oxyradical-associated damage to DNA did not accumulate uniformly across brain regions with age and was highest in brain regions that subserve spontaneous locomotor activity and motor coordination.

Age Factors↗

Attenuation of age-dependent oxidative damage to DNA and protein in brainstem of Tg Cu/Zn SOD mice.

Age-dependent accumulation of oxidative DNA and protein damage in brainstem and striatum was assessed in normal and transgenic (tg) mice which overexpress human Cu/Zn superoxide dismutase (h-SOD1). A marker of oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine (oxo8dG), was measured at 3, 12, and 18 months of age in control and tg mice. Cu/Zn SOD, but not MnSOD, activities in brainstems and striata from tg mice were increased compared to controls at all ages. At 18 months, oxo8dG levels were increased by 58% in brainstem and by 21% in striatum of control mice. In the tg mice, brainstem and striatal oxo8dG levels were increased to a lesser extent than in the corresponding controls. Protein oxidation (carbonyl content), was increased by 59% at 18 months in control brainstem, but not in striatum, and the increase was significantly attenuated in the tg mice. In summary, oxidative damage to DNA and protein increased with age in brainstem (and to a lesser extent in striatum), and augmented Cu/Zn SOD activity modified the extent of DNA and protein damage.

8-Hydroxy-2'-Deoxyguanosine↗