Interconversion of stroke scales. Implications for therapeutic trials

BACKGROUND AND PURPOSE: Stroke scales are intended to measure stroke severity for the purpose of clinical trials. Scores have been used to determine trial entry, to compare patient groups within or between trials, or as a secondary end point. The use of scores as an end point in meta-analysis has not been validated, but such analyses have nevertheless been performed when equivocal results have been obtained using the main outcome measure. The different scale designs suggest that conversion of scores may not be possible. We sought to determine whether scores on different scales could be interconverted. METHODS: A single observer scored 433 consecutive admissions to an acute stroke unit on the Canadian Neurological Scale, the middle cerebral artery Neurological Score (or Orgogozo scale), and the National Institutes of Health stroke scale. Data were separated into training and test sets, and linear regression was used to model conversion between scales. Prediction errors were calculated. Strokes were subdivided according to the Oxfordshire Community Stroke Project classification, and coefficients of determination were calculated for different subtypes. RESULTS: Conversion between Canadian and middle cerebral artery Neurological scales was satisfactory (R2 = 94.7%), and prediction errors were acceptable (absolute prediction error, 5.0 +/- 5). Conversion from the National Institutes of Health scale was worse (R2 = 87.5% to Canadian and 89.0% to Neurological Score), and prediction errors were significantly greater (Neurological Score error, 8.7 +/- 7; Canadian Neurological Scale error, 8.5 +/- 7.3; P < .005 for both). Coefficients of determination for interconversion were significantly worse for dysphasic patients with total anterior circulation strokes than for other stroke types (P < .01). Reweighting the motor component of the National Institutes of Health scale improved coefficients of determination and reduced prediction errors, but prediction error for conversion to the Canadian scale remained significantly greater than other conversions (P = .001). CONCLUSIONS: The Canadian Neurological Scale and the middle cerebral artery Neurological Score may reliably be converted. The National Institutes of Health scale cannot be used to predict these scores reliably, even with reweighting of the motor score. Interconversion is poorest for patients with dysphasia and total anterior circulation strokes. These results suggest that there will be more general difficulty in interconverting scales that use different test items and weighting. Meta-analysis using sequential changes in averaged scores from various stroke scales is not valid.     

Spectroscopy of diagnostic x rays by a Compton-scatter method

A method is described for measuring the energy spectra of diagnostic x rays using a high-resolution intrinsic germanium spectrometer. The method is applicable over the wide range of x-ray exposure rates normally used in radiography. Reduction of the high x-ray beam intensity to a level acceptable to the germanium spectrometer is achieved by measuring the spectrum of photons scattered through 90 degrees by a lucite disc. From this measured spectrum the primary spectrum is obtained by calculation. Some typical x-ray spectra are presented.     

Levonantradol, a new antiemetic with a high rate of side-effects for the prevention of nausea and vomiting in patients receiving cancer chemotherapy

Levonantradol, a new antiemetic compound pharmacologically related to the cannabinoids, was given to 17 patients who had experienced severe and protracted nausea and vomiting during previous courses of cancer chemotherapy, and to six patients receiving a first course of strongly emetic cytostatic treatment. Eight patients were partially protected from acute gastrointestinal disturbances. Of the 23 patients, 21 exhibited some toxicity, with six patients exhibiting major affective side-effects and 13 patients complaining of pain at the injection site. Levonantradol is an active antiemetic compound. Due to the rate of side-effects observed in our study however, we would not recommend use of this agent as an antiemetic drug.     

Urinary metabolite profile of PAH as a potential mirror of the genetic disposition for cancer

Polycyclic aromatic compounds such as polycyclic aromatic hydrocarbons or aromatic amines presently are considerably underestimated with regard to the formation of environmentally caused cancer diseases. The individual urinary metabolite profile raising from the PAH inhaled is invariant. This holds for tar-pitch aerosol exposed Wistar rats as well as for PAH-exposed workers. Significant individual differences of the urinary metabolite profile can be observed in different individuals. The differences reflect the different individual enzyme equipment. There is an individual correlation between the PAH-masses inhaled and the masses of their metabolites excreted in the urine; e.g. the excretion of phenanthrene varies from 5% to 20% for different coke workers. The PAH metabolite profile analysis appears to be a suitable tool to estimate the individual cancer.risk at PAH-exposed working places since the PAH-induced malign transformation is caused by specific PAH metabolites.