TO THE EDITOR: Research has shown that intravenous, but not oral ascorbate, can produce concentrations selectively toxic to cancer cells, which has renewed the interest in ascorbate as therapy for cancer.1,2 The protocol was approved by the ethics committee of The Center for Improvement of Human Functioning, Wichita, KS. Written informed consent was obtained. Methods. We conducted a mini-pilot ...

Lipoprotein(a), a variant of LDL carrying the adhesive glycoprotein apo(a), is a leading risk factor for cardiovascular disease. Lipoprotein(a) (Lp(a)) is found in humans and subhuman primates but rarely in lower mammals. Better understanding of the evolutionary advantage of this molecule should elucidate its physiological role. We developed a new mouse model with two characteristics of human m...

The steady-state kinetic behavior of dopamine 8monooxygenase (DBM) has been examined over a 1000-fold range of ascorbate concentrations. Kinetic plots exhibit extreme curvature indicative of apparent negative cooperativity in the interaction of D@M with ascorbate, with a calculated Hill coefficient of 0.150.30. The observed cooperativity is found to be independent of enzyme concentration and...

Plasma membranes isolated from wild-type Saccharomyces cerevisiae crude membrane fractions catalyzed NADH oxidation using a variety of electron acceptors, such as ferricyanide, cytochrome c, and ascorbate free radical. Plasma membranes from the deletion mutant strain coq3delta, defective in coenzyme Q (ubiquinone) biosynthesis, were completely devoid of coenzyme Q6 and contained greatly diminis...

The paper proposes a near infrared method able to directly and simultaneously quantify ascorbic acid and sodium ascorbate in powder blends for tableting and in vitamin C chewable tablets without any sample preparation. In the first step, calibration models for the quantification of ascorbic acid and sodium ascorbate in powder blends for tableting and subsequently in chewable vitamin C tablets (...

Hypoxia-inducible factor (HIF) plays an important role in determining patterns of gene expression in cancer. HIF is down-regulated in oxygenated cells by a series of Fe (II) and 2-oxoglutarate dependent dioxygenases that hydroxylate specific residues in the regulatory HIF-alpha subunits. Because these enzymes require ascorbate for activity in vitro we analyzed the effects of ascorbate on HIF in...

It has been well accepted that oxidative stress plays a crucial role in the pathogenesis of various chronic diseases including rheumatoid arthritis (RA). Although some studies suggest that uric acid as an important factor in precipitation of disease process by inducing inflammation, there is no satisfactory explanation for its role in disease complexity. Uric acid also acts as an antioxidant in...