Kaempferol Protects Against Retinal Photoreceptor Degeneration in a Mouse Model of Light-Induced Retinal Injury.

Purpose: Age-related macular degeneration (AMD) is a leading cause of blindness in developed countries with little in the way of treatment that prevents progression to end-stage disease. Kaempferol (KF) is a plant-derived dietary flavonoid that has demonstrated as a strong antioxidant showing neuroprotection in stroke models. We hypothesize that KF has protective effects against retinal degeneration and may serve as a therapeutic agent against AMD. Methods: BALB/c albino mice were assigned to 1 of 2 groups: control-treated or KF-treated retinal light injury mice. Mice were exposed to 8,000 lux cool white fluorescent light for 2 h to induce light injury. Control or KF was injected intraperitoneally after light injury for 5 days. Scotopic electroretinography (ERG) was recorded before light injury and 7 days after light injury. The retinal morphology and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed after light injury. Results: ERG a- and b-wave amplitudes were significantly reduced in the retinal light injury group compared with the nonretinal light injury group. Retinal light injury produced markedly thinning of the outer nuclear layer along with significant TUNEL-positive signals. In contrast KF treatments significantly attenuated reduction of ERG a- and b- wave amplitudes and the loss of the outer nuclear layer. Conclusions: KF protects retinal photoreceptors and preserves retinal function against retinal degeneration caused by light injury. These initial findings suggest that KF may represent a novel therapy for retinal degenerative conditions such as AMD.

Physical Activity Decreases Kidney Cancer Mortality.

BACKGROUND: To investigate associations of kidney cancer mortality with modifiable risk factors of obesity, physical activity, and smoking. METHODS: We evaluate baseline data from US National Health Information Survey from 1998 through 2004 linked to mortality data reporting deaths through 2006. The primary outcome variable was kidney cancer-specific mortality and primary exposure variables were self-reported physical activity and body mass index (BMI). We utilized multivariable adjusted Cox proportional hazards regression models, with delayed entry to account for age at survey interview. RESULTS: Among 222,163 individuals with complete follow-up data we identified 71 kidney cancer-specific deaths. In multivariate analyses, individuals who reported "any physical activity" were 50% less likely [adjusted hazard ratio (adjusted HR) 0.50, 95% CI 0.27-0.93, p = 0.028] to die of kidney cancer than non-exercisers, while obese individuals (BMI ≥ 30 kg/m2) were nearly 3 times more likely (adjusted HR 2.84, 95% CI 1.30-6.23, p = 0.009) compared to those of normal weight (BMI < 25 kg/m2). Compared to never smokers, former smokers were twice as likely to die of kidney cancer (adjusted HR 2.00, 95% CI 1.05-3.80, p = 0.034). CONCLUSION: Physical activity decreases and obesity increases the risk of kidney cancer mortality.

Obesity, Physical Activity and Bladder Cancer.

While smoking and exposure to certain chemicals are well-defined risk factors for bladder cancer, there is no consensus as to the roles of modifiable lifestyle factors, notably physical activity, and obesity. We evaluated associations of obesity and physical activity with bladder cancer risk by performing a system-wide search of PubMed for cohort and case-control studies focused on obesity, exercise, and bladder cancer. A total of 31 studies were identified that evaluated the associations of obesity and physical activity with bladder cancer risk: 20 focused on obesity, eight on physical activity, and three on both. There was marked heterogeneity in population composition and outcomes assessment. Fifteen (65%) of the obesity studies used prevalence or incidence as the primary outcome and seven (30%) used bladder cancer mortality. Ten (44%) observed positive and 13 (56%) null associations of obesity with bladder cancer. Three (100%) of three studies also noted strong positive associations of obesity with bladder cancer progression or recurrence. Ten (91%) of the physical activity studies analyzed prevalence or incidence and one (9%) mortality. One (9%) study observed positive, seven (64%) null, and three (27%) negative associations of physical activity with bladder cancer. Study heterogeneity precluded quantitative assessment of outcomes. Obesity is potentially associated with an increased risk of bladder cancer, particularly for progression, recurrence, or death. Further studies of physical activity and bladder cancer are needed to validate these observations and elucidate the associations of exercise with bladder cancer progression and mortality.