PMC:1281295 / 31868-32971 JSONTXT

{"target":"http://pubannotation.org/docs/sourcedb/PMC/sourceid/1281295","sourcedb":"PMC","sourceid":"1281295","source_url":"http://www.ncbi.nlm.nih.gov/pmc/1281295","text":"Intra- and interpersonal variability in urine samples.\nSeveral methods have been evaluated to “correct” for the variability in urine dilution across spot samples, the most popular being creatinine (Boeniger et al. 1993). Creatinine excretion varies because of many factors, including the size of the participant, so interindividual variation, especially among diverse populations, is large. Thus, creatinine-adjusted pesticide concentrations should never be compared among individuals of vastly different age groups (i.e., children vs. adults). Changes in creatinine excretion during pregnancy should be thoroughly evaluated before comparing with other women in similar age groups. The validity of creatinine adjustment may also be analyte dependent. Further studies to assess the variability of commonly measured analytes in urine should be conducted to identify the most effective sampling strategies for cohort studies. In all likelihood, sampling for nonpersistent chemicals will require multiple samples taken over the course of the study at regular intervals (e.g., weekly, monthly, semiannually).","divisions":[{"label":"Title","span":{"begin":0,"end":54}}],"tracks":[{"project":"2_test","denotations":[{"id":"16203262-8237794-28305611","span":{"begin":214,"end":218},"obj":"8237794"}],"attributes":[{"subj":"16203262-8237794-28305611","pred":"source","obj":"2_test"}]},{"project":"MyTest","denotations":[{"id":"16203262-8237794-28305611","span":{"begin":214,"end":218},"obj":"8237794"}],"namespaces":[{"prefix":"_base","uri":"https://www.uniprot.org/uniprot/testbase"},{"prefix":"UniProtKB","uri":"https://www.uniprot.org/uniprot/"},{"prefix":"uniprot","uri":"https://www.uniprot.org/uniprotkb/"}],"attributes":[{"subj":"16203262-8237794-28305611","pred":"source","obj":"MyTest"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#ec93c3","default":true},{"id":"MyTest","color":"#93ddec"}]}]}}