Vascular diseases are becoming an epidemic with an increasing aging population and increases in obesity and type II diabetes. Point-of-care (POC) diagnosis and monitoring of vascular diseases is an unmet medical need. Photoacoustic imaging (PAI) provides label-free multiparametric information of deep vasculature based on strong absorption of light photons by hemoglobin molecules. However, conventional PAI systems use bulky nanosecond lasers which hinders POC applications. Recently, light-emitting diodes (LEDs) have emerged as cost-effective and portable optical sources for the PAI of living subjects. However, state-of-art LED arrays carry significantly lower optical energy (<0.5 mJ/pulse) and high pulse repetition frequencies (PRFs) (4 KHz) compared to the high-power laser sources (100 mJ/pulse) with low PRFs of 10 Hz. Given these tradeoffs between portability, cost, optical energy and frame rate, this work systematically studies the deep tissue PAI performance of LED and laser illuminations to help select a suitable source for a given biomedical application. To draw a fair comparison, we developed a fiberoptic array that delivers laser illumination similar to the LED array and uses the same ultrasound transducer and data acquisition platform for PAI with these two illuminations. Several controlled studies on tissue phantoms demonstrated that portable LED arrays with high frame averaging show higher signal-to-noise ratios (SNRs) of up to 30 mm depth, and the high-energy laser source was found to be more effective for imaging depths greater than 30 mm at similar frame rates. Label-free in vivo imaging of human hand vasculature studies further confirmed that the vascular contrast from LED-PAI is similar to laser-PAI for up to 2 cm depths. Therefore, LED-PAI systems have strong potential to be a mobile health care technology for diagnosing vascular diseases such as peripheral arterial disease and stroke in POC and resource poor settings.

Significant advances have been made in the treatment of melanoma by targeting key cellular pathways, but additional targets are needed as many patients do not respond or relapse with resistant disease. MicroRNA-155 (MiR-155) has previously been shown to regulate melanoma cell growth and acts as a tumor suppressor. We tested a clinical population of melanoma tumors for miR-155 expression, and find that expression is low in most patients, although not predictive of outcome. We identified the protein kinase WEE1 as a novel target of miR-155. A mouse model of experimental metastasis finds that both increased expression of miR-155 and silencing of WEE1 lead to decreased metastases. Loss of miR-155 and increased expression of WEE1 may contribute to the metastatic phenotype in patients with melanoma.

Background and Objectives: Many cancers in young adulthood differ in terms of biology, histologic variation, and prognosis compared to cancer in other older age groups. Differences in cutaneous melanoma among young adults compared to other older age groups, as well as between sexes in young adults are not well studied.Methods: The National Cancer Database was queried for patients diagnosed with cutaneous melanoma between 2004 and 2017. Patient characteristics, disease factors, and treatment were stratified by age‐based cohorts and compared using standard univariate statistics. The Kaplan–Meier method and log‐rank tests were used to evaluate overall survival (OS) between age‐based cohorts and young adult sexes.Results: Of the 329 765 patients identified, 10.5% were between 18 and 39 years of age at diagnosis. Compared with other older age groups, young adult patients were more likely to be female and uninsured with higher proportions of superficial spreading melanoma, melanoma of the trunk and extremities, and earlier‐stage disease. Young adults had improved OS compared to other older age groups. Young male patients had a greater proportion of no insurance, nodular melanoma, higher‐stage disease, and decreased OS compared to young female patients. Additionally, while the 5‐year OS difference was statistically significant across all stages of disease between young males and females, the clinical significance is likely limited to later stages.Conclusions: Age and sex‐specific differences in cutaneous melanoma highlight distinct patterns and characteristics, emphasizing the need for tailored approaches to screening, diagnosis, and treatment.