Characteristics and behavior of dissolved organic matter in the Kumaki River, Noto Peninsula, Japan

Dissolved organic matter (DOM) in river water was studied to understand the transport behavior of DOM in a small watershed with forest and paddy fields. Field experiments were conducted under normal flow conditions in the Kumaki River, which is located in the central part of the Noto Peninsula in Japan, during the period 2009-2010. The concentrations and structural properties of fulvic acid-like components, which are the major components of DOM, were determined using three-dimensional excitation-emission matrix spectroscopy and high-performance size-exclusion chromatography. The relative fluorescence intensity for fulvic acid-like components at an excitation wavelength of 305-335 nm and an emission wavelength of 425-440 nm increased from the upper forest area to the lower paddy field area and increased seasonally in this river system in the following order: winter, autumn, spring, summer. Fulvic acid-like components with a higher molecular weight were observed in the summer samples. These results suggest that higher precipitation and agricultural activity in the summer season increase the amount of fulvic acid-like components with higher molecular weight that are transported from the watershed into the river. © 2014 The Japanese Society of Limnology

Association of L-type amino acid transporter 1 (LAT1) with the immune system and prognosis in invasive breast cancer

L-type amino acid transporter 1 (LAT1), also referred to as SLC7A5, is believed to regulate tumor metabolism and be associated with tumor proliferation. In invasive breast cancer, we clinicopathologically investigated the utility of LAT1 expression. LAT1 expression was evaluated via immunohistochemistry analyses in 250 breast cancer patients undergoing long-term follow-up. We assessed the relationships between LAT1 expression and patient outcomes and clinicopathological factors. Breast cancer-specific survival stratified by LAT1 expression was assessed. Human epidermal growth factor receptor 2 (HER2)-positive patients with metastasis received trastuzumab therapy. The density of tumor-infiltrating lymphocytes (TILs) was evaluated according to the International Working Group guidelines. In the current study, high LAT1 expression was significantly correlated with estrogen receptor (ER) negativity, progesterone receptor negativity, high histological grade, increased TILs, and programmed death ligand 1 positivity. Among the ER-positive and HER2-negative patients, high LAT1 was an independent indicator of poor outcomes (hazard ratio (HR) = 2.97; 95% confidence interval (CI), 1.16–7.62; p = 0.023). Moreover, high LAT1 expression was an independent poor prognostic factor in luminal B-like breast cancer with aggressive features (HR = 3.39; 95% CI 1.35–8.52; p = 0.0094). In conclusion, high LAT1 expression could be used to identify a subgroup of invasive breast cancer characterized by aggressive behavior and high tumor immunoreaction. Our findings suggest that LAT1 might be a candidate therapeutic target for breast cancer patients, particularly those with luminal B-like type breast cancer