The rise of Viagra

The old adage 'sex sells' has never seemed so apt. Not since the Pill has a drug made such an impact on the world stage, yet serious concerns surround the introduction and use of Viagra. Jenine Willis investigates.

Mutation of the type II transforming growth factor-beta receptor is coincident with the transformation of human colon adenomas to malignant carcinomas

The transforming growth factor-beta (TGF-beta) type II receptor (RII) is a colon cancer suppressor gene that is inactivated by mutation in 90% of human colon cancers arising via the microsatellite instability (MSI) pathway of carcinogenesis. To determine the pathophysiological consequence of RII mutations, we have determined the timing of their onset among 22 MSI human colon adenomas of varying stages. No RII mutations were detected in any early MSI adenoma, including all those with simple tubular or villous histology. The earliest RII mutation detected was in a region of high-grade dysplasia but was absent from the surrounding simple adenoma. Six additional RII mutations were all found in highly progressed adenomas that contained regions of frankly invasive adenocarcinoma. These RII mutations were detected in both the advanced adenomas and their adjacent regions of carcinoma. RII mutation is a late event in MSI adenomas and correlates tightly with progression of these adenomas to cancer.

High-resolution cross-sectional imaging of the gastrointestinal tract using optical coherence tomography: preliminary results

BACKGROUND

Optical coherence tomography (OCT) is a novel technique for noninvasive cross-sectional imaging with high spatial resolution (10 to 20 microm). OCT is similar to B-mode ultrasound except that it uses infrared light rather than ultrasound. We studied OCT imaging of the gastrointestinal (GI) tract in vitro to analyze the potential of this technique for endoscopic applications.

METHODS

Human gastrointestinal tissues harvested from surgical resection and autopsy specimens were used. Specimens were imaged within 5 hours of resection or snap frozen in liquid nitrogen. After imaging, OCT scan locations were carefully marked using dye microinjections, fixed, and prepared for routine histologic processing. OCT images were then compared and correlated with the histologic sections.

RESULTS

OCT images demonstrated clear delineation of the mucosa and submucosa in most specimens. Furthermore, microscopic structures such as crypts, blood vessels, or esophageal glands in the submucosa and lymphatic nodules were observed.

CONCLUSIONS

The resolution of OCT images of GI wall is sufficient to delineate the microscopic structure of the mucosa and submucosa. Potentially, OCT would allow in vivo imaging at endoscopy of the microstructure of the mucosa and submucosa. This would be particularly useful in the detection and staging of small lesions such as early stage cancers.

Lecturer-practitioners: serving two masters for a common cause

Is the theory-practice gap being bridged now that lecturer-practitioner posts exist in many parts of the country? Jenine Willis finds out how some practitioners are coping with the demands of the job.