MicroRNA-196a is a potential marker of progression during Barrett's metaplasia-dysplasia-invasive adenocarcinoma sequence in esophagus

Barrett's esophagus (BE)/Barrett's metaplasia (BM) is a recognized precursor of esophageal adenocarcinoma (EA) with an intermediary stage of dysplasia. The low yield and high cost of endoscopic screening of patients with BE underscores the need for novel biomarkers, such as microRNA (miRNA), which have emerged as important players in neoplastic progression for risk assessment of developing dysplasia/adenocarcinoma. Recently, we reported highly elevated levels of miRNA-196a (miR-196a) in EA and demonstrated its growth-promoting and anti-apoptotic functions. Here, we evaluated miR-196a as a marker of BE progression to low-grade dysplasia, high-grade dysplasia, and EA using microdissected paraffin-embedded tissues from 11 patients. Higher levels of miR-196a were observed in EA, BE, and dysplastic lesions compared with normal squamous mucosa, and in high-grade dysplasia compared with BE and low-grade dysplasia. Using frozen tumor tissues from 10 additional patients who had advanced EA, we evaluated the correlation of miR-196a with its in silico-predicted targets, keratin 5 (KRT5), small proline-rich protein 2C (SPRR2C), and S100 calcium-binding protein A9 (S100A9), which are down-regulated during BE progression. MiR-196a levels inversely correlated with the predicted target mRNA levels in EA. We confirmed that miR-196a specifically targets KRT5, SPRR2C, and S100A9 3' UTRs using miR-196a-mimic and luciferase reporter-based assays. In conclusion, this study identified miR-196a as a potential marker of progression of BE and KRT5, SPRR2C, and S100A9 as its targets.

Comparison of spot tests with AdultaCheck 6 and Intect 7 urine test strips for detecting the presence of adulterants in urine specimens

BACKGROUND

Several adulterants are used to mask tests for abused drugs in urine. Adulterants such as "Klear" and "Whizzies" contain potassium nitrite while "Urine Luck" contains pyridinium chlorochromate (PCC). The presence of these adulterants cannot be detected by routine specimen integrity check (pH, specific gravity, creatinine and temperature). We previously reported the development of rapid spot tests to detect the presence of these adulterants. AdultaCheck 6 and Intect 7 urine test strips are commercially available for detecting the presence of these adulterants along with specific gravity, creatinine and pH in urine.

METHODS

The performance of these two test strips for detecting adulterants was compared with the results obtained by spot tests.

RESULTS

Both AdultaCheck 6 and Intect 7 effectively detected the presence of nitrite and pyridinium chlorochromate in urine. Moreover, both test strips successfully detected the presence of glutaraldehyde, for which no spot test is currently available. High amount of glucose and ascorbic acid did not cause any false positive result with AdultaCheck 6 or Intect 7.

CONCLUSIONS

Both AdultaCheck 6 and Intect 7 can be used for checking the integrity of a urine specimen submitted for drugs of abuse testing.

Evaluering van studente

The successful evaluation of student learning involves: - the setting of detailed learning objectives; - the development of meaningful evaluation techniques; and - the practical application of such techniques