Efficacy of bilateral temporal artery biopsies and sectioning of the entire block of tissue for the diagnosis of temporal arteritis.

Giant cell arteritis (GCA) is a systemic vasculitis of medium and large sized blood vessels. The incidence is greater in women as compared to men (3:1) and most often occurs in the elderly. The most common symptoms are unilateral headaches, visual disturbances and scalp tenderness. If untreated, GCA may result in irreversible blindness. Prompt treatment is necessary to prevent progression of the disease, but accurate diagnosis is vital to prevent unwarranted side effects of the therapy. Temporal artery biopsy (TAB) remains the gold standard for diagnosis. TAB is an invasive procedure that can require up to 40 minutes to perform but is important for pathological confirmation. Variation amongst centers and practitioners exists in the type of biopsies performed. In 2013, a survey of over 1000 specialists showed that 37% recommended unilateral biopsy alone, 29% recommended initial unilateral biopsy with biopsy of the contralateral side if the first side is negative, 18% recommended bilateral biopsy in all cases, and 16% stated that their preference depended upon the degree of suspicion. Studies have shown that bilateral TAB can enhance diagnostic accuracy by 3 to 12.7%. Furthermore, temporal arteritis can involve the artery in a discontinuous fashion and there is no standardization of the number of sections or levels that should be examined in a segment of temporal artery. This study aims to shed light on the benefits of a bilateral temporal artery biopsy as well as to determine the optimum level for block sectioning for the diagnosis of temporal arteritis.

Secoisolariciresinol diglucoside abrogates oxidative stress-induced damage in cardiac iron overload condition.

Cardiac iron overload is directly associated with cardiac dysfunction and can ultimately lead to heart failure. This study examined the effect of secoisolariciresinol diglucoside (SDG), a component of flaxseed, on iron overload induced cardiac damage by evaluating oxidative stress, inflammation and apoptosis in H9c2 cardiomyocytes. Cells were incubated with 50 µ5M iron for 24 hours and/or a 24 hour pre-treatment of 500 µ M SDG. Cardiac iron overload resulted in increased oxidative stress and gene expression of the inflammatory mediators tumor necrosis factor-α, interleukin-10 and interferon γ, as well as matrix metalloproteinases-2 and -9. Increased apoptosis was evident by increased active caspase 3/7 activity and increased protein expression of Forkhead box O3a, caspase 3 and Bax. Cardiac iron overload also resulted in increased protein expression of p70S6 Kinase 1 and decreased expression of AMP-activated protein kinase. Pre-treatment with SDG abrogated the iron-induced increases in oxidative stress, inflammation and apoptosis, as well as the increased p70S6 Kinase 1 and decreased AMP-activated protein kinase expression. The decrease in superoxide dismutase activity by iron treatment was prevented by pre-treatment with SDG in the presence of iron. Based on these findings we conclude that SDG was cytoprotective in an in vitro model of iron overload induced redox-inflammatory damage, suggesting a novel potential role for SDG in cardiac iron overload.