C1: molecular interactions with activating systems.

The molecular events controlling complement activation have been gradually unravelled over the past three decades, stimulated by improved isolation procedures and a better understanding of the roles of individual proteins. In this review, Bob Sim and Ken Reid examine the interactions between C1q and its numerous ligands in the initiation of the classical pathway cascade.     

Congenitally corrected transposition of the great arteries and aortic coarctation--an uncommon association.

Congenitally corrected transposition of the great arteries, L-TGA, is a rare abnormality accounting for less than 0.5% of clinically apparent congenital heart disease. Age at time of diagnosis and survival rate are variable and depend mostly on associated anomalies. The authors present a clinical case of a twenty-four-year-old woman in whom, in a routine echocardiogram, congenitally corrected transposition of the great arteries and aortic coarctation were diagnosed, an unusual association. They describe the results of complementary exams (echocardiography, chest X-ray, electrocardiogram and cardiac angiography) that they believe to be useful for the correct diagnosis of this clinical situation. Additionally, the authors make a brief review of the literature relevant to the case.     

Psoas abscess due to retroperitoneal tuberculous lymphadenopathy

A case of psoas abscess occurring during treatment of tuberculous lymphadenopathy is described. There was no evidence of a bony origin for this abscess. It appears likely that it arose from involved glands on the posterior abdominal wall.     

Cholera, 1991--old enemy, new face]

The cholera epidemics of the XIXth century are described and reviewed. The extent, incidence and case-fatality rate for the disease in the seventh pandemic are described. The global epidemiological situation and its trend at the end of 1991 are analysed. A review of cholera epidemiology highlights the factors that might explain the less tragic nature of the disease today. The role of water, food and direct contagion in transmission of cholera over the last 20 years is considered in the light of recent studies and with special reference to the epidemic in Latin America, where the intense emotion aroused by the disease has prompted vigorous action that could produce significant and lasting progress in the health field.