The premalignant process in the gastric mucosa was studied by gastroscopic surveys of Colombian populations, and the prevalence of superficial gastritis, chronic atrophic gastritis, and intestinal metaplasia was calculated for population samples having a very high gastric cancer risk (Nariño), very low risk (Cartagena), and intermediate risk (Cali). The prevalence of individuals with normal mucosa in successive age groups was used to estimate "depletion" curves, which were taken as indicators of the dynamics of the premalignant process in each community. Differences corresponding to the geographic variation in stomach cancer risk were found: In the high-risk areas of Nariño, around 75% of the population developed some type of gastritis by 45 years of age, whereas in the low- and intermediate-risk population of Cartagena and Cali, the proportion of such lesions did not exceed 50% at age 45 or thereafter. The effect of environmental factors in early life seemed to be important in determining the prevalence of lesions in each population.

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Abstract. A qualitative and quantitative analysis of urinary lipids in the nephrotic syndrome is presented. The following lipids were identified in the urine of patients with the nephrotic syndrome: free cholesterol, cholesterol esters, triglycerides, free fatty acids, and phospholipids. Glass paper chromatography identified the cholesterol esters as palmitate, oleate, linoleate, and arachidonate, and identified the phospholipids as phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine.Urinary lipid excretion was much greater in patients with the nephrotic syndrome than in patients with chronic renal disease and minimal proteinuria, or in patients with hyperlipidemia from other causes.Urinary lipid excretion varied widely among the 13 patients with the nephrotic syndrome studied, and no quantitative correlation with serum lipid levels was observed. However, qualitatively at least, the proportion of cholesterol esters excreted in the urine was similar to the proportion of these esters in plasma. A good correlation was found between lipid excretion and glomerular permeability. Furthermore, during steroid therapy urinary lipid excretion decreased concomitant with a decrease in proteinuria. All these observations support the idea that lipiduria in the nephrotic syndrome is related to protein loss and that most of the lipid in the urine enters the glomerular filtrate in the form of lipoproteins.

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We conducted a case-control study to evaluate the effectiveness of BCG vaccination in preventing childhood tuberculosis (TB) in Cali, Colombia. We ascertained 178 cases aged 0 to 14 years from the respiratory clinics with cough or fever for at least three weeks and a positive chest X-ray for TB, as well as 320 controls who were from the same households but had no symptoms and negative X-rays. Using matched set multiple logistic regression analysis, we found the age- and sex-adjusted relative risk (RR) of TB among vaccinees compared with non-vaccinees to be 0.84 with 95% confidence limits (CL) from 0.43 to 1.62. There was, however, a significantly lowered relative risk of TB with increasing time since vaccination (RR = 0.83 per year since time of vaccination with 95% CL from 0.74 to 0.94.)