objectives: a reduction in bond strength of composite to bleached enamel has been reported immediately after bleaching treatment. application of some antioxidant agents may decrease the adverse effects of whitening agents on bond strength and enhance composite bond to enamel. this study aimed to assess the effect of green tea, sodium ascorbate, sage and grape seed extract on bond strength of co...

Cyclic light and dark-reared rats were exposed to intense visible light for various periods and then rhodopsin-measured following recovery in darkness for up to 14 days. Animals were injected with ascorbic acid or ascorbate derivatives at various doses prior to light exposure in green Plexiglas chambers. The results show that ascorbic acid administration elevates retinal ascorbate and reduces t...

All aerobic biological systems, including N(2)-fixing root nodules, are subject to O(2) toxicity that results from the formation of reactive intermediates such as H(2)O(2) and free radicals of O(2). H(2)O(2) may be removed from root nodules in a series of enzymic reactions involving ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase. We confirm here the presence of thes...

in order to evaluate the physiological and biochemical traits in response to salinity, six varieties of wheat were cultivated in a split plot based on randomized complete block design in the growth chamber in the department of agronomy, faculty of agriculture, university of maragheh. seedlings of wheat cultivars, in three to four leaves stage were treated with 200 mm nacl for 14 days. after the...

In highly purified plasma membrane fractions of at least six higher plant species, a specific high-potential b-type Cyt (redox potential at pH 7.0 between +120 and +160 mV, a band at 560-561 nm) has been detected (Asard et al., 1989; Askerlund et al., 1989). This component is reducible in vitro by sodium ascorbic acid and constitutes 60 to 80% of the total Cyt amount detectable in plant plasma ...

The aim of this study was to assess, using the DPPH assay, the antioxidant activity of several substances that could be proposed to immediately revert the problems caused by bleaching procedures. The percentage of antioxidant activity (AA%) of 10% ascorbic acid solution (AAcidS), 10% ascorbic acid gel (AAcidG), 10% sodium ascorbate solution (SodAsS), 10% sodium ascorbate gel (SodAsG), 10% sodiu...

Sodium saccharin and sodium ascorbate are known to promote urinary bladder carcinogenesis in rats following initiation with N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) or N-butyl-N-(4-hydroxybutyl) nitrosamine. Sodium salts of other organic acids have also been shown to be bladder tumor promoters. In addition, these substances increase urothelial proliferation in short term assays in r...

Various studies have reported a significant reduction in tensile bond strength of brackets when bonding is carried out immediately after bleaching. The purpose of this investigation was to determine the effect of an antioxidant agent on the tensile bond strength values of metal brackets bonded with composite resin to human enamel after bleaching with carbamide peroxide (CP). A total of 80 extra...

My experience (Cathcart 1975, 1976, 1978, 1979) in utilizing vitamin C in large doses has extended over a nine year period and has involved over 9,000 patients. Much of the original work with large amounts of vitamin C was done by Fred R, Klenner, M.D. (1948, 1949, 1971, 1974) of Riedsville, North Carolina. Klenner found that viral diseases could be detoxified and subsequently cured by intraven...