A protocol for urine collection and storage prior to DNA methylation analysis.

BACKGROUND: Urine poses an attractive non-invasive means for obtaining liquid biopsies for oncological diagnostics. Especially molecular analysis on urinary DNA is a rapid growing field. However, optimal and practical storage conditions that result in preservation of urinary DNA, and in particular hypermethylated DNA (hmDNA), are yet to be determined. AIM: To determine the most optimal and practical conditions for urine storage that result in adequate preservation of DNA for hmDNA analysis. METHODS: DNA yield for use in methylation analysis was determined by quantitative methylation specific PCR (qMSP) targeting the ACTB and RASSF1A genes on bisulfite modified DNA. First, DNA yield (ACTB qMSP) was determined in a pilot study on urine samples of healthy volunteers using two preservatives (Ethylenediaminetetraacetic acid (EDTA) and Urine Conditioning Buffer, Zymo Research) at four different temperatures (room temperature (RT), 4°C, -20°C, -80°C) for four time periods (1, 2, 7, 28 days). Next, hmDNA levels (RASSF1A qMSP) in stored urine samples of patients suffering from bladder cancer (n = 10) or non-small cell lung cancer (NSCLC; n = 10) were measured at day 0 and 7 upon storage with and without the addition of 40mM EDTA and/or 20 µl/ml Penicillin Streptomycin (PenStrep) at RT and 4°C. RESULTS: In the pilot study, DNA for methylation analysis was only maintained at RT upon addition of preserving agents. In urine stored at 4°C for a period of 7 days or more, the addition of either preserving agent yielded a slightly better preservation of DNA. When urine was stored at -20 °C or -80 °C for up to 28 days, DNA was retained irrespective of the addition of preserving agents. In bladder cancer and NSCLC samples stored at RT loss of DNA was significantly less if EDTA was added compared to no preserving agents (p<0.001). Addition of PenStrep did not affect DNA preservation (p>0.99). Upon storage at 4°C, no difference in DNA preservation was found after the addition of preserving agents (p = 0.18). The preservation of methylated DNA (RASSF1A) was strongly correlated to that of unmethylated DNA (ACTB) in most cases, except when PCR values became inaccurate. CONCLUSIONS: Addition of EDTA offers an inexpensive preserving agent for urine storage at RT up to seven days allowing for reliable hmDNA analysis. To avoid bacterial overgrowth PenStrep can be added without negatively affecting DNA preservation.

Taijin kyofusho and social anxiety and their clinical relevance in indonesia and Switzerland.

BACKGROUND: Taijin Kyofusho Scale (TKS) is an interpersonal fear to offend others and is defined by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as a culturally bound syndrome that occurs in Japan and Korea. Recently, cases with TKS have also been recognized in other cultures. The present questionnaire study investigated self-report TKS symptoms and social anxiety symptoms, and their clinical relevance in an Indonesian and Swiss sample. It also investigated whether self-construal is associated with TKS and social anxiety, and if self-construal is a mediator of the expected association between cultural background and social anxiety and TKS symptoms. METHOD: 311 Indonesian and 349 Swiss university students filled out the Liebowitz Social Anxiety Scale, the Taijin Kyofusho Scale, the Self-Construal Scale, self-report social phobia DSM-IV criteria, and rated their wish for professional help to deal with social fears. RESULTS: TKS and social anxiety symptoms were higher in the Indonesian than the Swiss sample. TKS symptoms were associated with clinical relevance in Indonesia, whereas in Switzerland only social anxiety symptoms were associated with clinical relevance. Independent self-construal was negatively associated and interdependent self-construal was positively associated with TKS and social anxiety symptoms. Interdependent self-construal mediated the association between cultural background and these symptoms. DISCUSSION: TKS might be a clinically relevant syndrome in all individuals or cultures with an interdependent self-construal or less independent self-construal. The proposal to include the fear of offending others in the DSM-V criteria of social phobia is supported by the present findings.