mCPP: an undesired addition to the ecstasy market.

A new ecstasy-like substance, meta-chlorophenylpiperazine (mCPP), has been detected in street drugs in the Netherlands. Theoretically, mCPP possesses the potential to become a non-neurotoxic alternative for methylenedioxymethamphetamine (MDMA), the regular psychoactive substance of ecstasy. Since its introduction on the Dutch market of synthetic drugs, the percentage of mCPP-containing tablets has increased, including both tablets that contain only mCPP and tablets containing a combination of mCPP and MDMA. These tablets occur in many different colours, shapes and sizes and with various logos, making it impossible to distinguish mCPP-containing tablets from regular MDMA tablets. In addition, the reports of users concerning the effects of mCPP are predominantly negative. All these aspects together lead to the conclusion that mCPP is an undesired addition to the ecstasy market from the user's perspective.

Strong increase in total delta-THC in cannabis preparations sold in Dutch coffee shops.

The total concentration of THC has been monitored in cannabis preparations sold in Dutch coffee shops since 1999. This annual monitoring was issued by the Ministry of Health after reports of increased potency. The level of the main psychoactive compound, Delta9-tetrahydrocannabinol (THC), is measured in marijuana and hashish. A comparison is made between imported and Dutch preparations, and between seasons. Samples of cannabis preparations from randomly selected coffee shops were analyzed using gas chromatography (GC-FID) for THC, CBD and CBN. In 2004, the average THC level of Dutch home-grown marijuana (Nederwiet) (20.4% THC) was significantly higher than that of imported marijuana (7.0% THC). Hashish derived from Dutch marijuana (Nederhasj) contained 39.3% THC in 2004, compared with 18.2% THC in imported hashish. The average THC percentage of Dutch marijuana, Dutch hashish and imported hashish was significantly higher than in previous years. It nearly doubled over 5 years. During this period, the THC percentage in imported marijuana remained unchanged. A higher price had to be paid for cannabis with higher levels of THC. Whether the increase in THC levels causes increased health risks for users can only be concluded when more data are available on adjusted patterns of use, abuse liability, bioavailability and levels of THC in the brain.

Error budget calculations in laboratory medicine: linking the concepts of biological variation and allowable medical errors.

BACKGROUND: Random, systematic and sporadic errors, which unfortunately are not uncommon in laboratory medicine, can have a considerable impact on the well being of patients. Although somewhat difficult to attain, our main goal should be to prevent all possible errors. A good insight on error-prone steps in the laboratory process is essential to achieving a structured system for error reduction. METHODS: Here, the process of laboratory medicine is divided into phases, and for each phase, an error frequency is presented. While error frequencies in the laboratory (pre-analytical to post-analytical) have been reported elsewhere, we also include them in the present paper. In order to investigate error frequencies in the pre-pre- and post-post-analytical phases, clinicians were asked to carefully answer questions concerning their ordering strategies for laboratory investigation and their interpretation of results. RESULTS: In the present study, the overall error rate in laboratory medicine was found to be 20.0%. The error percentages in the pre-pre- and post-post-analytical phase were about 12.0% and 5.0%, respectively. This indicates that, also on the clinical side, error reduction is desirable, especially in the requesting of laboratory investigation. Error reduction can be achieved through process redesigning by, for example, applying the Hazard Analysis and Critical Control Points approach. The error budget that clinicians might spend, based upon critical differences, is 26.9%. For the same test set and production circumstances, the overall biological variation is 7.9%. Clinicians thus take the error rates into account in their practical, daily use, and the ultimate achievable in laboratory medicine is biological variation. CONCLUSIONS: Several currently available software applications can aid error reduction in clinical chemistry. Both laboratory consultants and the use of information and communication technology are essential tools in optimizing the efficiency of laboratory medicine.

Tissue polypeptide-specific antigen (TPS) determinations before and during intermittent maximal androgen blockade in patients with metastatic prostatic carcinoma.

OBJECTIVE: To evaluate the prognostic significance of serially measured tissue polypeptide-specific antigen (TPS) levels in patients with metastatic prostatic carcinoma treated with intermittent maximal androgen blockade (MAB). To determine its value with respect to predicting response to treatment and time to clinical progression. Finally to compare TPS with prostate-specific antigen (PSA) measurements in terms of prognostic impact in patients with metastatic prostatic carcinoma. METHODS AND PATIENTS: TPS and PSA measurements were performed before start of and monthly during intermittent MAB in 68 patients participating in EORTC protocol 30954. Both TPS and PSA were measured in serum. Fifty-six patients from eight centers were included in the final analysis because at least three TPS values were available. TPS and PSA values were correlated with clinical course of the disease. Median follow-up was 21.3 months. Three patient groups were defined on clinical grounds: (a) clinically progressive disease (n=18); (b) clinically stable disease (n=33); and (c) patients who did not reach a predefined nadir PSA value following 9 months of treatment (n=5). RESULTS: Pretreatment TPS was significantly higher in the clinically progressive patients than in the other patient groups (p=0.0041). When grouping patients according to their pretreatment TPS values (cut-off value of 100 U/l) the pretreatment TPS value (>100 U/l) proved to be a statistically significant prognostic factor with respect to time to progression: elevated TPS was associated with a 3.8 increased risk for progressive disease (p=0.0055). Pretreatment PSA (>100 ng/ml) was of no prognostic value for time to progression. In five patients increase of TPS coincided with or preceded clinical progression during treatment, whereas PSA remained normal. CONCLUSION: Additional value of pretreatment TPS measurements in metastatic prostate cancer patients is found in defining the patients with rapid clinical progression. Following MAB an increase in TPS signifies clinical progression even if PSA is found to remain normal.