Iododeoxyuridine uptake in proliferating smooth muscle cells in vitro.

PURPOSE: Iododeoxyuridine (IUdR) is a halogenated pyrimidine recognized as the thymidine substitute in DNA. When labeled with iodine 125, IUdR can be used as a carrier to incorporate the isotope into DNA and target the dividing cells. The purpose of this study was to assess the maximum uptake of IUdR by proliferating smooth muscle cells (SMCs) in vitro to determine the optimal concentration to be administered in an in vivo experiment. The long-term goal is to use radioactive IUdR to inhibit SMC proliferation and recurrent stenosis of arteries after balloon angioplasty in vivo. MATERIALS AND METHODS: Porcine vascular SMCs were cultured in 5% fetal bovine serum medium and stimulated to proliferate by adding a medium containing 10% fetal bovine serum and insulin. IUdR was added to the proliferating SMCs at concentrations of 5, 10, 20, 30, and 40 micro mol/L on days 1, 3, 5, and 7 of incubation. One group of cells--the control group--did not receive IUdR. The SMCs were harvested and double-stained with an anti-IUdR antibody and propidium iodide, and fluorescence-activated cell scanning was performed to determine the ratio of IUdR-labeled cells to the total cell population for each IUdR concentration and at each time point. The data were measured three times at each time point. The doubling times, growth curve, and cell density of the proliferating SMCs were investigated by using the Coulter particle counter and digital microscopy. RESULTS: The percentage of proliferating SMCs that showed IUdR uptake increased from 1 to 5 days incubation with all concentrations of IUdR; the incorporation rate reached a peak value at day 5 and then decreased by day 7. IUdR uptake on day 5 was higher with concentrations of 10 and 20 micro mol/L. When compared with that of the control group, the doubling times increased with an increase in IUdR concentration, whereas the proliferating cell number and density decreased significantly by days 5 (P < .05) and 7 (P < .01). CONCLUSIONS: IUdR uptake peaked on day 5, and the optimal concentration of IUdR for in vitro uptake in proliferating SMCs was 10-20 micro mol/L. IUdR inhibited the proliferation of the SMCs, and the inhibitory effect was related to the concentration.

Evaluation of ProMED-mail as an electronic early warning system for emerging animal diseases: 1996 to 2004.

OBJECTIVE: To identify emerging animal and zoonotic diseases and associated geographic distribution, disease agents, animal hosts, and seasonality of reporting in the Program for Monitoring Emerging Diseases (ProMED)-mail electronic early warning system. DESIGN: Retrospective study. SAMPLE POPULATION: 10,490 disease reports. PROCEDURES: Descriptive statistics were collated for all animal disease reports appearing on the ProMED-mail system from January 1, 1996, to December 31, 2004. RESULTS: Approximately 30% of reports concerned events in the United States; reports were next most common in the United Kingdom, Canada, Australia, Russia, and China. Rabies, bovine spongiform encephalopathy, and anthrax were reported consistently over the study period, whereas avian influenza, Ebola virus, and Hantavirus infection were reported frequently in approximately half of the study years. Reports concerning viral agents composed more than half of the postings. Humans affected by zoonotic disease accounted for a third of the subjects. Cattle were affected in 1,080 reports, and wildlife species were affected in 825 reports. For the 10,490 postings studied, there was a retraction rate of 0.01 and a correction rate of 0.02. CONCLUSIONS AND CLINICAL RELEVANCE: ProMED-mail provided global coverage, but gaps in coverage for individual countries were detected. The value of a global electronic reporting system for monitoring emerging diseases over a 9-year period illustrated how new technologies can augment disease surveillance strategies. The number of animal and zoonotic diseases highlights the importance of animals in the study of emerging diseases.