Controversies in the management of anal high-grade squamous intraepithelial lesions.

Anal squamous dysplasia is recognized as a spectrum of disease that ranges from low-grade intraepithelial lesions (LSIL) to high-grade squamous intraepithelial lesions (HSIL) to invasive anal squamous cell carcinoma (SCC). Recent reports have shown a significant increase in both the incidence and prevalence of both HSIL and anal SCC, particularly in immunocompromised patients and in men who have sex with men. These lesions are associated with chronic infection with the human papillomavirus. The natural history is unknown, yet reports of untreated patients have shown progression rates of up to 50% in high risk patients. There are controversies as to the optimal management of patients with HSIL. However, there is evidence that screening of high-risk patients with anal cytology is useful in identifying those that require further evaluation. Examination of the anorectal region is enhanced with the use of high resolution anoscopy. Treatment modalities vary in terms of morbidity and success rates. Wide local excision is associated with significant morbidity. Newer therapies such as topical immunomodulation, photodynamic therapy and therapeutic vaccines have been proposed, but long-term follow-up is unavailable. High resolution anoscopy can be used in the office or in the operating room to direct therapy. Using a comprehensive approach of cytology and office-based and/or operating room procedures directed with high resolution anoscopy results in clearance of HSIL in up to 80% of patients, malignant progression in 1%, and less morbidity than wide local excision.

The El Salvador earthquakes of january and february 2001 : Context, characteristics and implications for seismic risk

The small Central American republic of El Salvador has experienced, on average, one destructive earthquake per decade during the last hundred years. The latest events occurred on 13 January and 13 February 2001, with magnitudes Mw 7.7 and 6.6, respectively. The two events, which were of different tectonic origin, follow the patterns of the seismicity of the region although neither event has a known precedent in the earthquake catalogue in terms of size and location. The earthquakes caused damage to thousands of traditionally built houses and triggered hundreds of landslides, which were the main causes of fatalities. The earthquakes have clearly demonstrated trends of increasing seismic risk in El Salvador due to rapid population expansion in areas of high shaking and landslide hazard, exacerbated by deforestation and uncontrolled urbanisation. The institutional mechanisms required for the control of land use and building practice are very weak and present a major obstacle to risk mitigation.(AU)