Interplay between the RNA Chaperone Hfq, Small RNAs and Transcriptional Regulator OmpR Modulates Iron Homeostasis in the Enteropathogen .

Iron is both essential for and potentially toxic to bacteria, so the precise maintenance of iron homeostasis is necessary for their survival. Our previous study indicated that in the human enteropathogen , the regulator OmpR directly controls the transcription of the , and genes, encoding the ferric uptake repressor and two transporters of ferric siderophores, respectively. This study was undertaken to determine the significance of the RNA chaperone Hfq and the small RNAs OmrA and RyhB1 in the post-transcriptional control of the expression of these OmpR targets.

Recommendations for a step-wise comparative approach to the evaluation of new screening tests for colorectal cancer.

Background: New screening tests for colorectal cancer continue to emerge, but the evidence needed to justify their adoption in screening programs remains uncertain.

Methods: A review of the literature and a consensus approach by experts was undertaken to provide practical guidance on how to compare new screening tests with proven screening tests.

Results: Findings and recommendations from the review included the following: Adoption of a new screening test requires evidence of effectiveness relative to a proven comparator test.

Changing epidemiology of colorectal cancer makes screening sigmoidoscopy less useful for identifying carriers of colorectal neoplasms.

Background: There is renewed interest in flexible sigmoidoscopy (FS) colorectal cancer (CRC) screening following trials showing significantly reduced CRC incidence and mortality.

Aims: To evaluate the potential usefulness of FS screening in our population.

Methods: We examined rectosigmoid (RS) cancer epidemiology in our Jewish population using Israel National Cancer Registry data, computed by CRC site, age groups, and gender.

Can a gastrointestinal pathologist identify microsatellite instability in colorectal cancer with reproducibility and a high degree of specificity?

Clinical features usually initiate evaluation for Lynch Syndrome (LS) but some colorectal cancer (CRC) histopathology findings are compatible with high microsatellite instability (MSI-H) that also occurs in LS. This led to the suggestion that pathologists request MSI analysis, which is an expensive addition to routine histology. We aimed to see if a Gastrointestinal Pathologist could identify MSI-H features with reproducibility and high (95%) specificity (MSI-H 95%).

Follow-up of patients undergoing both semiquantitated immunochemical fecal occult blood and colonoscopy examinations.

The semiquantitated immunochemical fecal occult blood test (I-FOBT) used for colorectal cancer (CRC) screening has had its long-term performance characteristics determined by clinical follow-up or sometimes by colonoscopy as the 'gold standard'. We reanalyzed a file of total colonoscopy patients who also prepared three I-FOBTs, processed by the OC-MICRO instrument, using at least 50 ng Hb/ml buffer threshold to determine a positive test. The performance of both tests was evaluated by the National Cancer Registry follow-up to identify new CRCs and by determining the effects of the number of tests prepared and their thresholds for analysis, sex, and age on results.