Effect of spectral distribution on isomerization of bilirubin in vivo

The purpose of our study was to compare the effects of narrow-spectrum blue light and broad-spectrum white light on the production of bilirubin photo-isomers in human infants with jaundice. Twelve preterm infants were studied under both white and blue light. Irradiance at 450 nm was controlled at 12 microW/cm2/nm for both light sources. Each light condition (white or blue) was administered for 12 hours. Bilirubin isomers (4Z,15E-bilirubin and lumirubin) were measured before therapy and after 12 hours of each sequential light condition. The percentage of 4Z,15E-bilirubin was greater under blue light than under white light (P less than 0.01) phototherapy. There was no significant difference in percentage lumirubin under white or blue light therapy. Our data indicate that blue light is more effective than white light in producing 4Z,15E-bilirubin in vivo. Our study demonstrates that when irradiance in the bilirubin absorbance spectrum is constant, the color of light (spectral distribution) will determine the relative concentrations of photo-isomers produced.     

Electronic Screening Improves Efficiency in Clinical Trial Recruitment

This study evaluated the performance of an electronic screening (E-screening) method and used it to recruit patients for the NIH sponsored ACCORD trial. Out of the 193 E-screened patients, 125 met the age criterion (“age ≥ 40”). For all of these 125 patients, the performance of E-screening was compared with investigator review. E-screening achieved a negative predictive accuracy of 100% (95% CI: 98-100%), a positive predictive accuracy of 13% (95% CI: 6-13%), a sensitivity of 100% (95% CI: 45-100%), and a specificity of 84% (95% CI: 82-84%). The method maximized the use of a patient database query (i.e., excluded ineligible patients with a 100% accuracy and automatically assembled patient information to facilitate manual review of only patients who were classified as “potentially eligible” by E-screening) and significantly reduced the screening burden associated with the ACCORD trial.     

Predicted reduction in lung cancer risk following cessation of smoking and radon exposure

Recently there has been considerable public and regulatory concern that radon, produced by the decay of naturally occurring uranium, can accumulate in homes, offices, and schools at levels that may substantially increase the risk of lung cancer. The major cause of lung cancer is smoking, and radon appears to interact multiplicatively with smoking in causing lung cancer. Thus, the most effective way to reduce the increased risk of lung cancer resulting from radon exposure is to cease smoking. In this paper, a model for the risks associated with radon exposure that was developed by a committee of the National Academy of Sciences is used to calculate the benefits, in terms of reduction in lifetime risk of lung cancer, of ceasing to smoke, ceasing radon exposure, or ceasing both. Ceasing to smoke is considerably more beneficial than ceasing radon exposure, and thus policymakers addressing the health effects of radon should place priority on encouraging individuals to stop smoking.     

Predicting the carcinogenicity of the aromatic amine derivatives tested in the second UKEMS collaborative study

The carcinogenicity prediction and battery selection (CPBS)procedure was used to analyze the short-term in vitro and invivo genotoxicity results obtained during the Second UKEMS CollaborativeStudy. In accordance with preliminary animal bioassay results,CPBS predicted correctly the carcinogenicity of benzidine, 4,4'-diaminoterphenyland 4-dimethylaminoazobenzene. CPBS predicted the non-carcino-genkityof 4-cyanodimethylaniline, a chemical of as yet unknown carcinogenicity.Moreover, CPBS indicated that for the chemicals included inthe UKEMS study, highly predictive as well as cost-effectivebatteries consisting of three short-term assays could be identified.     

The use of community health aides as perceived by their supervisors in Jamaica, West Indies (1987/88)

A research project funded by the Commonwealth Caribbean Medical Research Council began in February 1987, to study aspects of the situation in connection with the 508 Community Health Aides employed in the Government Service in Jamaica. This report deals specifically with the role of Supervisors (Public Health Nurses and Midwives) in relation to the Aides employed in the Government Primary Health Care Service, Jamaica. There were 77 Supervisors interviewed, and questionnaires were returned from all 4 Administrative Health areas in Jamaica. The Supervisors reported that they could supervise more Aides in the community setting than in the clinic setting alone. In-service training was an integral part of the Aide program, and there was regular evaluation of the Aides, with at least an annual evaluation in keeping with the policy of the agency. Resource persons from other sectors assist in continuing education programs for the Aides. The main weakness were in selection and training (political involvement in selections; training period of 8 weeks too short, need to strengthen attitude to work and develop self-discipline); numbers and distribution (too few Aides, too many based in clinics instead of the community, uneven geographic assignments); conditions of service (inadequate remuneration, lack of upward promotion, delays in permanent appointments); supervision, evaluation and communication (inadequte supportive supervision professional staff shortage, need to strengthen evaluation and communication between Aides and Supervisors). Strengths of the Aide Program include living and working in the same district and being part of a health team.     

Application of the carcinogenicity prediction and battery selection method to recent National Toxicology Program short-term test data

Identification of potentially cancer-causing chemicals is a priority in our society. Short-term assays for mutation or chromosomal damage, which are rapid, inexpensive, and reproducible, have found widespread use; however, concern has arisen recently because such assays do not coincide completely with the standard rodent bioassay for carcinogenesis. Lack of perfect correlation is not surprising, given the complex, multicausal nature of the carcinogenic process. We have developed methodologies for interpreting short-term tests to predict carcinogenicity, which allow consideration of the influence of the proportion of carcinogens expected in the tested chemicals, the complexities of the rodent carcinogenesis bioassay, and factors affecting the worth of information. These methodologies are applied to a set of data on genotoxicity and carcinogenicity of 73 chemicals (NTP-73) recently published by the National Toxicology Program; they illustrate that with this approach, batteries of short-term tests can indeed be predictive of rodent carcinogenicity or noncarcinogenicity and that batteries are more predictive than the Salmonella assay alone. The analysis is validated using an additional group of chemicals with results in the same short-term tests as NTP-73.     

Characterization of calculus matrix calcification nucleator.

The nucleator of dental calculus matrix calcification, in vitro, was analyzed. Attention focused on proteolipid singularity, amino acid composition and related polarity, and phospholipid components. The data were compared to those of the nucleator of Bacterionema matruchotii calcification.