Drug testing by urine and hair analysis: complementary features and scientific issues

Hair analysis and urinalysis are complementary tests for establishing drug use. Hair analysis provides long-term information, from months to years, concerning both the severity and pattern of drug use. In contrast to this, urinalysis can indicate only drug use, and then generally only that which has occurred within the last 2–3 days. Field studies have demonstrated that hair analysis is considerably more effective than urinalysis at identifying drug users. This difference is due to the wider surveillance window of hair analysis and to the susceptibility of urinalysis to evasive maneuvers. The main concerns with urinalysis are endogenous evidentiary false positives caused by passive drug exposure, e.g., ingestion of poppy seed. This problem arises from the hypersensitivity of the urine test, i.e. the need to use low cut-off levels in order to compensate for the temporary recording of drug use. This problem does not occur with hair analysis since its wide window of detection and permanent record of drug use ensure that the detection efficiency of the test is not compromised by the use of more effective cut-off levels guarding against passive endogenous drug exposure. On the other hand, exogenous evidentiary false positives due to external contamination of hair by drugs present in the environment (e.g., smoke) are the main concern of hair analysis. This problem, however, can be effectively avoided by washing the hair specimen, by kinetic analyses of the wash data, and by measurement of metabolites. The possibility of bias due to race and/or hair color is avoided by the exclusion of melanin from the analysis of hair. The safety and effectiveness of hair testing has been established by extensive field studies with over 400 000 specimens.     

Problems associated with the diagnosis of vitality in burned bodies

The most important signs of vitality in burned bodies are soot deposits in the respiratory tract, the esophagus and the stomach as well as elevated CO-Hb values in the blood. But these findings show only that a person was exposed to fire fumes while alive; they are no indicator for vital heat exposure. As the external findings in burned bodies are often not very conclusive due to postmortem consumption by the fire, the internal findings are all the more important. Macroscopic signs that hot fumes were inhaled may be edematous swelling and vesicular detachment of the mucosa in the pharynx, the larynx and/or the upper section of the esophagus. As histological changes in the respiratory tract soot deposits, vesicular detachment of the epithelium, hyperemia and edema of the tracheal and bronchial mucosa as well as increased secretion of mucus have been described. These findings may partly be absent although the victim was alive during the fire, which can make diagnosis more difficult. Especially in peracute deaths vitality findings are usually sparse. The significance of the macroscopic and histological parameters of vitality was systematically investigated on the basis of our own autopsy material from the years 1996-2002 (88 cases) and compared with the statements found in the literature. In our study material, the vitality parameters were incomplete in 23% of the burned corpses. In 3% of the cases the question whether there was an antemortem heat exposure could not be answered.     

Non-Discriminatory,Envy Free Provision of a Collective Good: A Note

In a setting in which the provision of acollective good is at stake the ``principleof generality as equal treatment'' isrelated to the concept of ``envy free nettrades''. This leads to an operationalformulation of the fundamental liberal aimof non-discriminatory politics in terms ofstated preferences or bids. Starting fromsuch bids a simple axiomatic justificationfor ``schematically equal taxes'' (everyonepays the same amount) is given.     

“The Unnamed Third”: Roberta Kevelson's Legal Semiotics and the Development of International Law

International Journal for the Semiotics of Law - Revue internationale de Sémiotique juridique -