Comparison of biomarkers of oxidative stress and cardiovascular disease in humans and chimpanzees (Pan troglodytes).

In the oxidative stress hypothesis of aging, the aging process is the result of cumulative damage by reactive oxygen species. Humans and chimpanzees are remarkably similar; but humans live twice as long as chimpanzees and therefore are believed to age at a slower rate. The purpose of this study was to compare biomarkers for cardiovascular disease, oxidative stress, and aging between male chimpanzees and humans. Compared with men, male chimpanzees were at increased risk for cardiovascular disease because of their significantly higher levels of fibrinogen, IGF1, insulin, lipoprotein a, and large high-density lipoproteins. Chimpanzees showed increased oxidative stress, measured as significantly higher levels of 5-hydroxymethyl-2-deoxyuridine and 8-iso-prostaglandin F(2alpha), a higher peroxidizability index, and higher levels of the prooxidants ceruloplasmin and copper. In addition, chimpanzees had decreased levels of antioxidants, including alpha- and beta-carotene, beta-cryptoxanthin, lycopene, and tocopherols, as well as decreased levels of the cardiovascular protection factors albumin and bilirubin. As predicted by the oxidative stress hypothesis of aging, male chimpanzees exhibit higher levels of oxidative stress and a much higher risk for cardiovascular disease, particularly cardiomyopathy, compared with men of equivalent age. Given these results, we hypothesize that the longer lifespan of humans is at least in part the result of greater antioxidant capacity and lower risk of cardiovascular disease associated with lower oxidative stress.

Rescue of bacteriophage T7 DNA polymerase of low processivity by suppressor mutations affecting gene 3 endonuclease.

The DNA polymerase encoded by gene 5 (gp5) of bacteriophage T7 has low processivity, dissociating after the incorporation of a few nucleotides. Upon binding to its processivity factor, Escherichia coli thioredoxin (Trx), the processivity is increased to approximately 800 nucleotides per binding event. Several interactions between gp5/Trx and DNA are required for processive DNA synthesis. A basic region in T7 DNA polymerase (residues K587, K589, R590, and R591) is located in proximity to the 5' overhang of the template strand. Replacement of these residues with asparagines results in a threefold reduction of the polymerization activity on primed M13 single-stranded DNA. The altered gp5/Trx exhibits a 10-fold reduction in its ability to support growth of T7 phage lacking gene 5. However, T7 phages that grow at a similar rate provided with either wild-type or altered polymerase emerge. Most of the suppressor phages contain genetic changes in or around the coding region for gene 3, an endonuclease. Altered gene 3 proteins derived from suppressor strains show reduced catalytic activity and are inefficient in complementing growth of T7 phage lacking gene 3. Results from this study reveal that defects in processivity of DNA polymerase can be suppressed by reducing endonuclease activity.

Oxidative stress profiling: part II. Theory, technology, and practice.

Many of the most serious human diseases have a strong association with the steady-state level of oxidative damage in tissues. On an individual level this damage is defined as the patient's oxidative stress status (OSS). OSS is associated with many of the major age-related diseases such as cancer, heart disease, diabetes, and Alzheimer's disease, as well as with the aging process itself. In general, the greater the OSS of the individual, the higher the risk for disease development. To further understand the role that OSS has as a causative or an associated factor for these diseases, and to develop more effective personalized therapy to minimize OSS, requires a reliable means to measure the many different components contributing to an individual's OSS. This procedure is called oxidative stress profiling (OSP) and represents a new strategy to simultaneously assess an individual's OSS as well as to identify key physiological parameters, such as the hormone, lipid, antioxidant, or iron profile, that may be responsible for that individual's OSS. The OSP strategy provides physicians with information that enable them to make a more accurate diagnosis of the patient's condition and to recommend specific types of therapy based on better scientific data. Follow-up studies of the patient would then be conducted using these same tests until the OSS of the patient has been minimized. The OSP strategy is particularly well suited for a personalized health optimization program. The procedure is based on measuring both the steady-state levels of oxidative damage in nucleic acids, proteins, and lipids and the protective and defense processes of these components using blood, urine, and breath samples. Testing individuals before and after a controlled amount of exercise (70% VO2) may also help to obtain greater sensitivity and reproducibility. Evaluation of test results to obtain an integrated calculated OSS result for a patient represents a major challenge. One approach is to present the test results on a percentile bases, allowing results of different tests to be integrated into one or a few parameters, such as an oxidative stress and an antioxidant index. This article presents a general overview and rationale of the concept of the oxidative stress profile, tests to be used, and examples of how it may be applied.