Costs and cost effectiveness of health checks conducted by nurses in primary care: the Oxcheck study.

OBJECTIVE--To measure the costs and cost effectiveness of the Oxcheck cardiovascular risk factor screening and intervention programme. DESIGN--Cost effectiveness analysis of a randomised controlled trial using clinical and economic data taken from the trial. SETTING--Five general practices in Luton and Dunstable, England. SUBJECTS--2205 patients who attended a health check in 1989-90 and were scheduled for re-examination in 1992-3 (intervention group); 1916 patients who attended their initial health check in 1992-3 (control group). Participants were men and women aged 35-64 years. INTERVENTION--Health check conducted by nurse, with health education and follow up according to degree of risk. MAIN OUTCOME MEASURES--Cost of health check programme; cost per 1% reduction in coronary risk. RESULTS--Health check and follow up cost 29.27 pounds per patient. Estimated programme cost per 1% reduction in coronary risk per participant was between 1.46 pounds and 2.25 pounds; it was nearly twice as much for men as women. CONCLUSIONS--The cost to the practice of implementing Oxcheck-style health checks in an average sized practice of 7500 patients would be 47,000 pounds, a proportion of which could be paid for through staff pay reimbursements and Band Three health promotion target payments. This study highlights the considerable difficulties faced when calculating the costs and benefits of a health promotion programme. Economic evaluations should be integrated into the protocols of randomised controlled trials to enable judgments to be made on the relative cost effectiveness of different prevention strategies.     

The extent of chromosomal aberrations induced by chemotherapy in non-human primates depends on the schedule of administration

We utilized a non-human primate model, the rhesus monkey (Macaca mulatta), to quantitate the extent of chromosomal damage in bone marrow cells following chemotherapy. Thiotepa, etoposide, and paclitaxel were chosen as the chemotherapy agents due to their distinct mechanisms of action. Chromosomal aberrations were quantitated using traditional Giemsa stain. We sought to evaluate the extent to which genotoxicity was dependent on the schedule of administration by giving chemotherapy as either a bolus or a 96 h continuous infusion. Neutropenia and areas under the concentration curve (AUCs) were monitored to ensure comparable cytotoxicity and dose administered. At least 100 metaphases were scored in each marrow sample by an investigator unaware of the treatment history of the animals. All three drugs produced a statistically significant higher percentage of abnormal metaphases following bolus chemotherapy (p<0.0001, p=0.0015 and p<0.0001 for thiotepa, etoposide and paclitaxel, respectively). We conclude that infusional administration of thiotepa, etoposide and paclitaxel is less genotoxic to normal bone marrow cells than is bolus administration. These results suggest infusional regimens may be considered where there are concerns about long-term genotoxic sequelae, including secondary cancer, teratogenicity, or possibly the development of drug resistance. We believe this approach provides a reproducible model in which drugs and eventually, regimens can be compared.     

Stabilization of nanoparticles under biological assembly conditions using peptoids

Sequence-specific polymers are proving to be a powerful approach to assembly and manipulation of matter on the nanometer scale. This has been most impressive in the case of DNA, and progress has been made toward templating inorganic nanoparticles using DNA nanostructures. One obstacle to this progress is that inorganic nanomaterials are often incompatible with DNA assembly conditions, which involve aqueous solutions high in either or both monovalent and divalent salt. Synthetic oligopeptide ligands have been shown by others to improve nanoparticle stability in high concentrations of monovalent salt. Ligands that are peptoids, or sequence-specific N-functional glycine oligomers, allow precise and flexible control over the arrangement of binding groups, steric spacers, charge, and other functionality. We have synthesized short peptoids that can prevent the aggregation of gold nanoparticles in high-salt environments including divalent salt, and allow coadsorption of a single DNA molecule. This degree of precision and versatility is likely to prove essential in bottom-up assembly of nanostructures and in biomedical applications of nanomaterials.     

A radiometric assay of pyridoxamine (pyridoxine) 5′-phosphate oxidase

A radiometric assay for pyridoxamine 5′-phosphate oxidase (pyridoxamine (pyridoxine) 5′-phosphate:O₂ oxidoreductase (deaminating), EC 1.4.3.5) has been developed utilizing N-(5′-phosphopyridoxyl)[³H]tryptamine. This assay is more sensitive than previously used colorimetric and fluorescent assays for this oxidase and furthermore is applicable to erythrocytes. Tritiated substrate is incubated with an enzyme sample in the presence of excess unlabeled truptamine and the radiolabeled tryptamine product is extracted into toluene and quantitated by liquid scintillation counting.     

The influence of noninstantaneous mixing on the measurement of fluxes of solute and water across a biological membrane

The usual method of tracer analysis for calculating the flow across a biological membrance is based on the assumption that the compartments on either side are well-stirred. Thus, the validity of the rate of flow determination is questionable for cases where the distribution of tracer is not homogeneous. In this study, a mathematical model is developed for the purpose of estimating the effect of slow mixing on the calculation of the flow rate. The model is applied to the measurement of the rate of flow of aqueous humor through the living eye by use of a fluorescent dye as a tracer. A transit time of several minutes for the passage of fluorescein through the posterior chamber and an extended period of nonuniform distribution of fluorescein in the anterior chamber was observed. The effect of slow mixing on the calculated flow rate is compared to rates derived from equations based on the assumption of rapid mixing. Aqueous flow rates determined by the two methods were found to agree to within ≈20%.     

Viral inclusions in raccoon liver cells.

Three young raccoons (Procyon lotor), two from Michigan and one from Arizona, died suddenly from acute infections. Intranuclear inclusion bodies and viral particles typical of herpesvirus were seen in liver cells from all three. Inclusions also were seen in the nuclei of endothelial cells in the lung, liver, glomeruli and reticuloendothelial cells of the spleen. The source of the infection was not determined, but possible transmission from other species could not be ruled out.