A portable system for identifying urinary tract infection in primary care using a PC-based chromatic technique.

An approach is described for monitoring urine samples using a portable system based on chromatic techniques and for predicting urinary tract infection (UTI) from the results. The system uses a webcam-computer combination with the screen of a computer visual display unit as a tuneable illumination source. It is shown that the system can operate in a robust manner under ambient lighting conditions and with potential for use as a point of care test in primary care. The present approach combines information on urine liquid concentration and turbidity. Its performance in an exploratory study is compared with microbiological culture of 200 urine samples, of which 79 had bacterial growth >10(5) colony forming unit/millilitre (cfu ml(-1)) indicative of UTI. It is shown that both sensitivity and negative predictive value of 0.92 could be achieved.

Cocaine and metabolites in human graying hair: pigmentary relationship.

OBJECTIVE: To assess differences in the binding of cocaine, cocaethylene, and benzoylecgonine among pigmented and senile white hairs of the graying human cocaine abuser. DESIGN: A sheath of graying hair in the region around the apex of the head was gathered between the thumb and index finger then cut and removed about 2 mm proximal to the scalp. The graying hair was divided into pigmented and senile white of equal weights and lengths and then analyzed by gas chromatography/mass spectrometry chemical ionization. Twenty-nine such pairs were analyzed. SUBJECTS: Male cocaine abusers, ages 33-55 years hospitalized for substance abuse. Informed consent was obtained and confidentiality assured. MAIN OUTCOME MEASURES: Concentrations of cocaine, cocaethylene and benzoylecgonine in ng were assessed for each of 29 paired hair samples by gas chromatography/mass spectrometry chemical ionization. RESULTS: There were statistically significant differences between pigmented and senile white sections of paired samples. Cocaine (ng/mg hair, mean +/- SD) was 31.5 +/- 30.2 for pigmented hair vs 14.9 +/- 19.8 for senile white portions; (p < 0.0001). Cocaethylene (ng/mg hair, mean +/- SD) 3.22 +/- 5.0 (pigmented) vs 0.52 +/- 0.88 (senile white); (p < 0.0016). Benzoylecgonine (ng/mg hair, mean +/- SD) 5.1 +/- 5.3 (pigmented) vs 3.9 +/- 4.8 (senile white); (p < 0.005). CONCLUSION: Melaninated pigmented hair seems to bind more cocaine, cocaethylene and benzoylecgonine than white hair in the same subject.