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Background: Urinary Ca2+ excretion increases with dietary NaCl. NaCl-induced calciuria may be associated with hypertension, urinary stone formation and osteoporosis, but its mechanism and long-term effects are not fully understood. This study examined alterations in the expressions of renal Ca2+ transporters, channels and claudins upon salt loading to better understand the mechanism of salt-induced urinary Ca2+ loss.Methods: Eight-week old Wistar-Kyoto rats were fed either 0.3% or 8% NaCl diet for 8 weeks. Renal cortical expressions of Na+/Ca2+ exchanger 1 (NCX1), Ca2+ pump (PCMA1b), Ca2+ channel (TRPV5), calbindin-D28k, and claudins (CLDN-2, -7, -8, -16 and -19) were analyzed by quantitative PCR, western blot and/or immunohistochemistry.Results: Fractional excretion of Ca2+ increased 6.0 fold with high-salt diet. Renal cortical claudin-2 protein decreased by approximately 20% with decreased immunological staining on tissue sections. Claudin-16 and -19 expressions were not altered. Renal cortical TRPV5, calbindin-D28k and NCX1 expressions increased 1.6, 1.5 and 1.2 fold, respectively.Conclusions: Chronic high-salt diet decreased claudin-2 protein and increased renal TRPV5, calbindin-D28k, and NCX1. Salt loading is known to reduce the proximal tubular reabsorption of both Na+ and Ca2+. The reduction in claudin-2 protein expression may be partly responsible for the reduced Ca2+ reabsorption in this segment. The concerted upregulation of more distal Ca2+-transporting molecules may be a physiological response to curtail the loss of Ca2+, although the magnitude of compensation does not seem adequate to bring the urinary Ca2+ excretion down to that of the normal-diet group. [ABSTRACT FROM AUTHOR]

Most tumor markers have low detection rates for curable stages of cancer and are therefore not satisfactory for use in a healthy population. A new cancer risk calculation method, AminoIndex Cancer Screening (AICS), uses multiple plasma amino acid concentrations to calculate the risks for several cancers simultaneously and is suggested to have a high detection rate for early-stage cancers and a low false-positive rate for adenomas. Here, we describe a male patient with a family history of colorectal cancer who underwent AICS. He was judged as Rank C for colorectal cancer, which reportedly has a specificity of 95%, a sensitivity of 41%, and an estimated positive predictive value of 0.67%. He underwent colonoscopy for a secondary screening, which revealed a 10-mm adenoma-like lesion in the ascending colon, with a biopsy report of partial carcinoma. The tumor was endoscopically removed and diagnosed as carcinoma in situ (carcinoma in adenoma). This early detection method allowed complete resection of the carcinoma, and the patient is in remission. This is the first case in which a curable cancer was detected using AICS. With its high detection rate for early-stage cancers and its ease of use, this tool, which recently became available in Japan, may be beneficial for simultaneous screening of the general population for multiple cancers. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2145080259887842.