A Chlamydomonas reinhardtii mutant lacking CGL71, a thylakoid membrane protein previously shown to be involved in photosystem I (PSI) accumulation, exhibited photosensitivity and highly reduced abundance of PSI under photoheterotrophic conditions. Remarkably, the PSI content of this mutant declined to nearly undetectable levels under dark, oxic conditions, demonstrating that reduced PSI accumul...

Photodynamic therapy (PDT) is a clinically approved and rapidly developing cancer treatment regimen. It is a minimally invasive two-stage procedure that requires administration of a photosensitizing agent followed by illumination of the tumor with visible light usually generated by laser sources. A third component of PDT is molecular oxygen which is required for the most effective antitumor eff...

BACKGROUND Pyruvic acid is an alpha-keto acid that presents keratolytic, antimicrobial, and sebostatic properties as well as the ability to stimulate new collagen production and elastic fibers formation. Because of its low pKa and its small dimension, it penetrates rapidly and deeply through the skin, so far as to be considered a potent chemical peel agent. It has proven its efficacy for the tr...

BACKGROUND Development of resistance to 5-fluorouracil (5-FU) is a major problem in treatment of various cancers including pancreatic cancer. In this study, we reveal important resistance mechanisms and photochemical strategies to overcome 5-FU resistance in pancreatic adenocarcinoma. METHODS 5-FU resistant (5-FUR), epithelial-to-mesenchymal-like sub-clones of the wild type pancreatic cancer ...

damage. UVB exposure of human skin induces skin alterations, including erythema, which is characteristic of sunburn cells, and prolonged UVB exposure results in the formation of wrinkles, the degradation of matrix molecules, the development of elastosis, and an increased risk of epithelial skin cancer. Keratinocytes are the main target of UV, and play a central role in several responses of phot...

The human eye is constantly exposed to sunlight and artificial lighting. Light transmission through the eye is fundamental to its unique biological functions of directing vision and circadian rhythm and therefore light absorbed by the eye must be benign. However, exposure to the very intense ambient radiation can pose a hazard particularly if the recipient is over 40 years of age. There are age...

BACKGROUND Aging of the population, in particular the "baby boomers," has resulted in increased interest in methods of reversal of photodamage. Non-invasive treatments are in high demand, and our knowledge of mechanisms of photodamage to skin, protection of the skin, and repair of photodamage are becoming more sophisticated and complex. OBJECTIVE The objective of this study is to determine if...

Ninety two patients with porphyria cutanea tarda (PCT) were examined ophthalmically in a paired case control study. The incidence of pinguecula and of pterygium was 8 and 2 times higher respectively, in PCT patients than in the control group. The photodamage to the conjunctiva is considered to be a result of the photoactivity of uroporphyrin in the tissues.

Fractional resurfacing has become an increasingly popular treatment for photodamage. Non-ablative and ablative fractional resurfacing modalities both have a variety of different devices that may be utilized for treatments. Each modality has its own benefits and drawbacks. In this article, the authors offer preliminary observations from hands-on experience with several different ablative fractio...