Abstract: Provided are an antiviral agent and an antiviral food as novel methods for utilizing a Euglena-derived material. The antiviral agent and antiviral food, both comprising a Euglena-derived material as an active ingredient, are to be used for preventing or treating an infectious disease caused by an envelope-free RNA virus. Examples of the envelope-free RNA virus include rotaviruses belonging to Reoviridae. Examples of the Euglena-derived material include Euglena, a hot water extract of Euglena, paramylon and an alkali-treated paramylon.

Abstract: The present invention provides a hemiacetal ester prodrug of the pyridone carboxylic acid antibacterial drug, wherein the prodrug is characterized in that, (i) it is hydrolyzed promptly after intestinal absorption and regenerates the pyridone carboxylic acid antibacterial drug as a drug substance, (ii) a one-dose package is possible by preventing chelate-formation in intestines in an oral administration, and (iii) the normal bacterial flora of the intestinal bacterial flora is not influenced at all until the ester is absorbed, because the hemiacetal-type esterification is executed on the carboxylic acid which is a center of the antibacterial action, resulting in prevention of the pseudomembranous colitis. The prodrug is an alkoxy carbonyl hemiacetal-type ester represented by the chemical formula (I), which is useful as a prodrug for inhibiting the enteric-bacterium-shift side effect, and can be used in combination with polyvalent metal-containing medicines.

Abstract: The present invention provides a blood marker for renal cancer, more specifically, a blood marker that can be practically used for clinical diagnosis of renal cancer. The present invention also provides a blood marker that can be practically used for follow-up after treatment such as surgery and during treatment such as medication for renal cancer. A blood marker for renal cancer selected from the group consisting of Galectin-1, Galectin-3, and ?-enolase. Galectin-1 and/or Galectin-3 as a blood marker for renal cancer for use in an examination performed before diagnostic imaging. ?-Enolase as a blood marker for renal cancer for use in monitoring during and/or after treatment for renal cancer.