The Radiographic Prepatellar Fat Thickness Ratio Correlates With Infection Risk After Total Knee Arthroplasty.

BACKGROUND: Obesity has been associated with complications after a total knee arthroplasty (TKA). Surgical site infection (SSI) after TKA is one of the feared complications as it increases revision rates, costs, and stress to the patient. There is conflicting evidence in the literature regarding body mass index (BMI) and risk of infection after TKA, and some studies have suggested that site-specific fat distribution may be a better metric for determining risk of postoperative infections. Here, we investigate the correlation of soft tissue distribution about the knee to SSI after TKA. METHODS: We retrospectively review 572 patients who underwent primary TKA at a single institution from 2006 to 2010. We introduce the prepatellar fat thickness ratio (PFTR) as a radiographic means to quantitatively assess fat distribution about the knee and evaluate this measurement's ability to assess the risk of developing an SSI after TKA. RESULTS: The PFTR was shown to be a better predictor of SSI than BMI in both the univariate (P = .05) and multivariate (P = .01) analyses. CONCLUSION: Although BMI cannot fully account for variations in adipose distribution, the PFTR may account for this variability and may be a helpful tool for assessing a patient's preoperative risk of SSI after TKA.

Extension of Drosophila Lifespan by Rhodiola rosea Depends on Dietary Carbohydrate and Caloric Content in a Simplified Diet.

The root and rhizome extract of Rhodiola rosea has been extensively used in traditional medicine to improve physical and mental performance and to protect against stress. We, and others, have reported that R. rosea can extend lifespan in flies, worms, and yeast. We also previously found that the extract can act independently of dietary restriction (DR), a treatment that can extend lifespan in a range of model organisms. In flies, DR is implemented through a reduction in dietary yeast content. Here, we report that the ability of R. rosea extract to extend lifespan in flies is dependent on the carbohydrate and caloric content when supplemented with a simplified diet composed of yeast and sucrose. R. rosea extract elevated the sugar content in flies and down-regulated hexokinase expression, suggesting that it perturbs carbohydrate metabolism in flies. In our previous studies, bananas, barley malt, and corn syrup provided dietary carbohydrates, and R. rosea extract could extend lifespan with a range of caloric levels. We conclude that the lifespan-extending effect of R. rosea extract in flies is dependent on dietary carbohydrate and caloric contents coupled with an interaction with complex dietary components present in bananas, barley, or corn.

The impact of green tea polyphenols on development and reproduction in Drosophila melanogaster.

Although, green tea has numerous health benefits, adverse effects with excessive consumption have been reported. Using Drosophila melanogaster, a decrease in male fertility with green tea was evidenced. Here, the extent of green tea toxicity on development and reproduction was investigated. Drosophila melanogaster embryos and larvae were exposed to various doses of green tea polyphenols (GTP). Larvae exposed to 10 mg/mL GTP were slower to develop, emerged smaller, and exhibited a dramatic decline in the number of emerged offspring. GTP protected flies against desiccation but sensitized them to starvation and heat stress. Female offspring exhibited a decline in reproductive output and decreased survival while males were unaffected. GTP had a negative impact on reproductive organs in both males and females (e.g., atrophic testes in males, absence of mature eggs in females). Collectively, the data show that high doses of GTP adversely affect development and reproduction of Drosophila melanogaster.