An increase in the concentration of free radicals, measured using electron spin resonance (ESR) spectroscopy, can reflect the degree of oxidative stress. An in vivo ESR spectroscopy technique has been developed to measure free radical reactions even in the whole animal non-invasively using nitroxide free radicals, which are sensitive to both redox state and ROS. Rates of penetration of nitroxide free radicals into the skin and their distribution in the skin have been measured by the ESR technique. Thus, the generation and distribution of radicals produced during normal metabolism or induced after irradiation of the skin by sunlight can be measured. (more…)

Some genetic mutations appear to accelerate certain features of aging only within a single tissue. There are a very large number of these conditions, which might be referred to as unimodal progeroid syndromes. Here only three examples are considered: one that has a major impact on sun-exposed skin, one that results in an early onset of the most common form of dementia alzheimer, Alzheimer’s disease, and another that results in early-onset Parkinson’s disease. (more…)

The word cognizable is being used to access the features and functions of T cells which may still unknown or understood. In other words, aspects of the functioning of T cells and details of the operation that already exist and are waiting to be unveil.

The first visible effects of aging affect clonal restriction, and clonal dominance of T-cell as biomarkers of aging in the elderly (more…)

The accumulative waste theory of aging, also known as the waste accumulation or garbage accumulation theory of aging, proposes that molecules damaged by oxidation and their by products (e.g., aged collagen, damaged enzymes), and damaged mitochondria (organelles responsible for cellular energy production) accumulate in postmitotic (non dividing cells) causing dysfunction, toxicity, aging, and cell death (see Error Catastrophe Theory of Aging).

There are several mechanisms by which garbage accumulation affects cells. (more…)

The largest single risk factor for developing cancer is age. The incidence of cancer increases exponentially with age, although death from cancer (cancer mortality) may decline at very old age. The inevitable age-dependent rise in cancer incidence is a feature of multicellular organisms that contain a substantial fraction of mitotic cells. Organisms such as flies and worms are composed primarily of post-mitotic cells, and hence do not develop cancer. (more…)

Reactive radicals of nitrogen (nitric oxide and derivatives such as peroxynitrite) and of oxygen (superoxide anion, hydrogen peroxide, hydroxyl radical) can inflict considerable damage on macromolecules (proteins, nucleic acids, complex lipids), give rise to carcinogens (e.g., nitrosamines), and trigger (or sometimes prevent) apoptotic death of cells such as macrophages and vascular epithelial cells. There are mechanisms for scavenging and antagonizing those highly reactive species of molecules and for repairing damage caused by them. (more…)

Aging theories cover the biochemical, genetic, and physiological properties of a typical organism, and the way these properties change with time. Genetic theories deal with speculations regarding the identity of aging genes, accumulation of errors in the genetic machinery, programmed senescence, and telomeres. Biochemical theories are concerned with energy metabolism, generation of free (more…)