DNA damage by ribose: Inhibition at high ribose concentrations.

Nucleobases and DNA react non-enzymatically with sugars, and generate DNA-advanced glycation end products (DNA-AGEs). Incubation of plasmid pBr322 with ribose for 3-7 days caused the transformation of the supercoiled plasmid to the open circular and linear forms. Removal of sugar after an initial 24 h incubation resulted in marked enhancement in the transformation rate. Enhancement in transformation was also observed when bovine serum albumin (BSA) exposed to ribose for short durations was incubated with plasmid in absence of the sugar. The effect on DNA was attenuated when excess ribose remained in the incubation mixture of ribose and protein. The data suggested that an increase in ribose concentration in the vicinity of DNA could be damaging and the damage exacerbated, if sugar levels fell subsequently. Incubation of herring sperm DNA with ribose resulted in a concentration and time-dependent increase of N2-carboxyethyl-2’-deoxyguanosine (CEdGA,B). The concentration of CEdGA,B, however, did not increase further when ribose was removed from the reaction mixture.

Comparative effectiveness of CaNa3DTPA and tiron along with alpha-tocopherol against beryllium-induced biochemical alterations in rats.

The therapeutic efficacy of chelating agents CaNa3DTPA (calcium trisodium diethylene triamine penta acetic acid) and Tiron (sodium-4,5-dihydroxy-1,3-benzene disulphonate) with and without antioxidant, alpha-Tocopherol was evaluated in the treatment of beryllium-induced toxicity in female albino rats. The animals were exposed to beryllium (as beryllium nitrate) at a dose of 1 mg/kg (ip) once a day for 28 consecutive days followed by chelation therapy by CaNa3DTPA (0.1 mM/kg, ip) and Tiron (471 mg/kg, ip) with and without alpha-Tocopherol (25 mg/kg, orally) for 5 consecutive days after toxicant administration. Tissue biochemistry revealed severe alterations in liver and kidney. A significant fall in total protein and glycogen contents, alkaline phosphatase, adenosine tri-phosphatase and succinic dehydrogenase level was noticed. On the contrary, an elevation in acid phosphatase was recorded. The significant rise in hepatic lipid peroxidation and decreased level of hepatic reduced glutathione showed toxicity due to beryllium. CaNa3DTPA with alpha-Tocopherol showed moderate therapeutic efficacy while Tiron in combination with alpha-Tocopherol exerted statistically more beneficial effects to reverse biochemical alterations in different variables altered due to beryllium intoxication.

Experiencia con Gadolinio DTPA en RNM / Experience with Gadolinium DTPA in RNM

Se analizan las indicaciones y efectividad del Gadolinio en 30 pacientes con estudios del SNC y columna vertebral

Effect of trisodium pentetat on the distribution of cadmium in some body organs & on hepatic metallothionein in rats.

The pre- and post-treatment with calcium trisodium diethylene-triaminepentaacetic acid (CaNa3DTPA) was investigated for their efficacy to mobilize cadmium (Cd) from various tissues and hepatic metallothionein (MT) in Cd-exposed rats. Pretreatment with CaNa3 DTPA significantly reduced the hepatic and renal Cd absorption while, post Cd treatment with CaNa3 DTPA was effective in reducing renal and brain Cd. Pretreatment with CaNa3DTPA significantly increased the Cd induced hepatic metallothionein (MT) level, MT-bound Cd, Zn and Cu contents while, post treatment with CaNa3DTPA reduced the hepatic MT, MT-bound Cd compared to Cd alone treated rats.