Receiver operating characteristic curves for analysis of the results of cervicovaginal smears. A useful quality improvement tool

OBJECTIVES: To assess the value of receiver operating characteristic curves (ROCs) as a tool for improvement in the evaluation of cervicovaginal smear results. DESIGN: We reviewed the results of cervicovaginal smear interpretation for 1 year by 10 different cytopathologists working in the same laboratory (total number of cases, 45,356) and compared them with results of histologic evaluation of corresponding biopsies (n = 2090, 4.6%), the latter taken to be the gold standard. Receiver operating characteristic curves were generated for the laboratory as a whole and for individual cytopathologists. RESULTS: Analysis of these receiver operating characteristic curves was surprisingly informative. They showed that cytopathologists with different diagnostic thresholds could be distinguished from each other. A difference in diagnostic threshold could be distinguished from a difference in diagnostic accuracy. CONCLUSIONS: We conclude that while receiver operating characteristic curves for cervicovaginal smear interpretation have limitations, the results can be used for quality improvement.     

Intensive care for people with serious mental illness

This article describes the development of a psychiatric 'intensive care' service for men and women with serious or enduring forms of psychotic disorder. The authors suggest that such a residential therapeutic service may be an essential part of the development of community care for the most vulnerable people served by mental health services.     

Results of elective stenting of branch-ostial lesions

Coronary stenting using both Palmaz-Schatz and Gianturco-Roubin stents for branch ostial lesions was performed in 48 patients with high success and low complication rates. The 6-month event-free survival rates were high in these patients.     

Computer modelling of tool loads and press/tool deflections in multistage forging

A mathematical model of the deflections arising during forging in a multistage press provides the basis for the development of a computer package which can be used to predict the dimensional changes in workpieces occurring at each stage, due to a change at any one stage and individual tool loads and total press load for any given set of conditions. The program can be used to speed up tool setting times by enabling the correct shut-heights for each forming stage to be determined without trial and error. It can be used also to investigate the effects of changes (either deliberate or unintentional) in process conditions such as: lubrication, billet volume or hardness, on the dimensions of the finish forged component. The program has been validated by comparing its output with the results of experiments comprising: single-stage, two-stage and three-stage forging undertaken on a vertical crank press.     

Styrene/N-phenylmaleimide copolymer miscible blends

The morphological changes that occur in molded phenolic specimens during long-term heat aging tests have been observed in optical and scanning electron microscopy. The changes in morphology include shrinking and the formation of both cracks and charred zones in the phenolic matrix. The relationship of these morphological changes to weight losses and flexural strength losses was demonstrated.     

The basics of the intelligent processing of materials

Currently, most high-technology materials are inspected for quality after processing, with very low yields, great variability and high costs. Intelligent process control potentially enables much greater yields of high-quality materials, which will reduce the designers’ inhibitions about consideration of new, emerging materials in the design of new products, and enable their earlier intro-duction into systems and their components. Development of concurrent engineering tools and systems, with the development of intel-ligent processing of materials technology as a cornerstone to concurrent engineering, will then lead to long-term changes in the way that organizations conduct product development. Potential benefits include a large reduction in the time required to develop new products, increased quality and reduced life-cycle costs.     

1H magnetic resonance spectroscopy of chronic cerebral white matter lesions and normal appearing white matter in multiple sclerosis

OBJECTIVES: To test the hypothesis that irrecoverable neurological deficit in multiple sclerosis is associated with axonal loss. METHODS: 1H magnetic resonance spectroscopy (MRS) was carried out in a group of patients with clinically definite multiple sclerosis (n=31). Using this technique, the apparent concentration of NA ([NA] the sum of N-acetyl aspartate (NAA), a neuronal marker, and N-acetylaspartylglutamate has been compared in four groups of patients with multiple sclerosis classified as relapsing-remitting, secondary progressive, primary progressive, benign, and a control group. RESULTS: In the patients with relapsing-remitting disease (n=9) there was a highly significant reduction of apparent NA (median 8.73 mM, range 6.86 mM-10.74 mM, P=0.0008) from an area of high signal compared with the control group (median 11.97 mM, range 10.55 mM-14.5 mM). In the patients with secondary progressive disease (n=10), there was again a highly significant reduction of apparent NA (median 7.82 mM, range 3.5 mM-10.3 mM, P=0.0003) from an area of high signal compared with the control group. In the patients with primary progressive disease (n=6) there was once again a highly significant reduction of apparent NA (median 8.83 mM, range 6.95 mM-9.89 mM, P<0.002) from an area of high signal compared with the control group. In the patients with benign disease, however, there was no significant difference in the apparent NA (median 10.5 mM, range 8.53 mM-12.8 mM, P>0.05) from an area of high signal compared with the control group. In the patients with benign disease (n=5) there was also no significant difference in the apparent NA (median 10.74 mM, range 8.58 mM-13.4 mM, P>0.3) from an area of normal appearing white matter compared with the control group. In the patients with primary progressive disease, however, there was a significant reduction of apparent NA from an area of normal appearing white matter (median 8.78 mM, range 8.7 mM-12.38 mM, P< 0.025) compared with the control group. There was a significant inverse correlation between [NA] from lesions in the patients with multiple sclerosis and disability as measured on the Kurtzke expanded disability scale score (r= -0.364, 0.05>P>0.02). CONCLUSION: These findings support the hypothesis that axonal loss is important in the development of disability in multiple sclerosis. They also provide evidence for axonal loss in normal appearing white matter in patients with primary progressive disease.