Freddy Siegel

Learn More
Several recent reports have indicated an increased prevalence of gallstones in association with pregnancy. If these reports are true, the early puerperium should be a favorable time to detect the disease in its initial stages and follow its natural course. Accordingly, the gallbladder was examined by ultrasound in 980 women during the immediate postpartum(More)
Blood and hair samples collected from 54 male workers occupationally exposed to lead were assayed for this metal by graphite furnace atomic absorption spectrophotometry. Blood ZPP and urinary ALA-D were also determined for most subjects tested. Blood and hair lead concentrations (PbB and PbH) ranged from 100 to 770 ng/ml (10 to 77 micrograms/100 ml) (mean(More)
A placebo-controlled, double-blind study on the efficacy of a hepatitis A vaccine (SmithKline Beecham Biologicals) was started in a region of Chile in September 1990, using hepatitis B vaccine as control. A total of 260 healthy children, 6-15 years of age, negative for antibody to hepatitis A virus (anti-HAV), antibody to HAV immunoglobulin M (IgM),(More)
BACKGROUND Sanitary and socioeconomic changes and the identification of new causative virus, have changed the epidemiology of hepatitis in Chile. AIM To study the natural history of acute hepatitis caused by virus A, E and non A-E in Chilean adults. PATIENTS AND METHODS A special study protocol was followed for patients with a clinical picture of acute(More)
BACKGROUND Colorectal cancers are often chemoresistant toward antitumour drugs that are substrates for ABCB1-mediated multidrug resistance (MDR). Activation of the Wnt/β-catenin pathway is frequently observed in colorectal cancers. This study investigates the impact of activated, gain-of-function β-catenin on the chemoresistant phenotype. METHODS The(More)
Little is known about hepatitis E virus (HEV) prevalence in South American countries. Anti-HEV was studied in 1,773 subjects from 1,360 blood donors of 3 cities in Chile, 72 in health care workers, 241 inmates in state jails, and in 100 Araucanian indians. Anti-HEV was detected in 109 out of 1,360 (8.0%) total donors (6.3%, 6.1%, and 18.8% from the cities(More)
We report here the use of ultrasound-guided percutaneous fine needle aspiration gastric biopsies in three patients with endoscopically negative biopsies. Two men, ages 60 and 64, and one woman, age 64, with signs and symptoms of weight loss, abdominal pain, and early satiety, had barium contrast studies suggestive of thickened gastric walls of the antrum(More)
Over a year period, 60 of 172 patients presenting with upper gastrointestinal bleeding were treated by endoscopic thermocoagulation. Entry criteria included active bleeding (pulsatile or oozing), a visible vessel, sentinel clot or the presence of a pigmented protuberance at the ulcer crater. Hemostatic therapy was performed using the heat probe. The(More)