M.L. De Castro

Spatio-temporal Upwelling Trends along the Canary Upwelling System (1967–2006)

Spatio‐temporal trends in upwelling patterns were studied along the Canary Upwelling System for the period 1967–2006. The northwestern coast of African from lat 20°N to 32°N is observed to be under a permanent upwelling regime characterized by coastal sea surface temperatures (SST) colder than the oceanic ones at the same latitude. The temperature difference is termed the temperature upwelling index (UISST). This regime is consistent with the wind‐derived Ekman transport (UIW), which is observed near the coast and is directed offshore. This index shows the existence of upwelling‐favorable conditions all year but has an annual cycle characterized by more upwelling‐favorable conditions from April to September, with a maximum in July, and less upwelling‐favorable conditions from October to March, with a minimum in December to January. Although both indices can be used to characterize the phenomenon, only UIW values were used to quantify upwelling change during the four decades under review because this index is less sensitive to external factors compared to UISST. A strong decrease in upwelling intensity has been observed in all seasons. In particular, the summer (winter) decrease is on the order of 45% (20%) of the mean amplitude of the upwelling cycle.

A comparative study of two histological techniques for the identification of cytomegalovirus infection in colorectal biopsies from patients with chronic inflammatory bowel disease

BACKGROUND the role that cytomegalovirus (CMV) plays in inflammatory bowel disease (IBD) is controversial. The diagnosis of CMV infection in IBD depends on viral identification with hematoxylin-eosin (HE) or immunohistochemistry (IHC). Our aim was to compare the sensitivity of HE and IHC for this diagnosis in IBD patients. PATIENTS AND METHODS a case-control study. Our database was searched for IBD patients with HE- or IHC-based CMV-positivity from 1997 to 2007. Controls were selected among IBD inpatients matched for age and year of diagnosis with CMV. Their clinical characteristics were analyzed. HE and IHC were performed on biopsies from cases and controls at 6 months before and after inclusion in the study. In the statistical analysis, p values below 0.05 were considered significant. RESULTS ten IBD patients with CMV infection were identified. IBD-CMV patients were more steroid-resistant or steroid-dependent (p = 0.03), and underwent a higher number of colonic biopsies (p = 0.03). From 97 biopsies analyzed, 12 were HE-negative and IHC-positive, and 3 showed reversed results. The sensitivity of HE was 58.6%, 95% CI (38.9-78.3), and that of IHC was 89.7%, 95% CI (76.8-100). We did not find a good level of agreement between both techniques: kappa value 0.55, 95% CI (0.36-0.75). CMV positivity with IHC was associated with the use of more than one immunosuppressant drug, OR 13.5, 95%CI (1.2-152.2). Antiviral treatment was useful for CMV patients with steroid-dependent and steroid-refractory IBD. CONCLUSIONS IHC shows a 30% higher sensitivity than HE for the diagnosis of CMV infection in IBD patients. There is no good level of agreement between both histological techniques.