Genotyping for DQA1 and PM loci in urine using PCR-based amplification: effects of sample volume, storage temperature, preservatives, and aging on DNA extraction and typing.

Urine is often the sample of choice for drug screening in aviation/general forensic toxicology and in workplace drug testing. In some instances, the origin of the submitted samples may be challenged because of the medicolegal and socioeconomic consequences of a positive drug test. Methods for individualization of biological samples have reached a new boundary with the application of the polymerase chain reaction (PCR) in DNA profiling, but a successful characterization of the urine specimens depends on the quantity and quality of DNA present in the samples. Therefore, the present study investigated the influence of storage conditions, sample volume, concentration modes, extraction procedures, and chemical preservations on the quantity of DNA recovered, as well as the success rate of PCR-based genotyping for DQA1 and PM loci in urine. Urine specimens from male and female volunteers were divided and stored at various temperatures for up to 30 days. The results suggested that sample purification by dialfiltration, using 3000-100,000 molecular weight cut-off filters, did not enhance DNA recovery and typing rate as compared with simple centrifugation procedures. Extraction of urinary DNA by the organic method and by the resin method gave comparable typing results. Larger sample volume yielded a higher amount of DNA, but the typing rates were not affected for sample volumes between 1 and 5 ml. The quantifiable amounts of DNA present were found to be greater in female (14-200 ng/ml) than in male (4-60 ng/ml) samples and decreased with the elapsed time under both room temperature (RT) and frozen storage. Typing of the male samples also demonstrated that RT storage samples produced significantly higher success rates than that of frozen samples, while there was only marginal difference in the DNA typing rates among the conditions tested using female samples. Successful assignment of DQA1 + PM genotype was achieved for all samples of fresh urine, independent of gender, starting sample volume, or concentration method. Preservation by 0.25% sodium azide was acceptable for sample storage at 4 degrees C during a period of 30 days. For longer storage duration, freezing at -70 degrees C may be more appropriate. Thus, the applicability of the DQA1 + PM typing was clearly demonstrated for individualization of urine samples.     

GC/MS determination of zolpidem in postmortem specimens in a voluntary intoxication

An ingestion of an unknown quantity of Ivadal (zolpidem) tablets in a case of drug abuse is described. The authors report a new and fast method of analysing and determining the zolpidem concentration in postmortem specimens. Quantitation of zolpidem was performed by ethyl acetate extraction from alkalinized body fluids before GC/MS analysis. The analyses were performed without any complex sample clean-up steps and with little sample material. Postmortem concentrations of zolpidem in body fluids are given. The proposed method is a rapid procedure of analysis in cases of deliberate poisoning with the sedative-hypnotic drug, zolpidem.     

Interlocal Agreements and Multilateral Institutions: Mitigating Coordination Problems of Self-Organized Collective Action

ABSTRACT

In the United States, competition among cities for economic development tends to be the norm. Cities are also collaborating more to improve their economic advantage. However, transaction costs inhibit various of interlocal agreements from being formed. This study examines the role of multilateral institutions in facilitating interlocal agreements for economic development. An analysis of survey data collected from city governments in eleven US metropolitan areas highlights the importance of regional institutions in moderating the effect of coordination problems on the formation of developmental joint venture agreements. The findings complement extant research on the governance mechanisms that mitigate transaction costs of collective action.     

Are Overlapping Local Governments Competing With Each Other When Issuing Debt?

Local public services are produced through various overlapping jurisdictions. This study examines how the issuance of municipal general obligation bonds is affected by the tax policies of overlapping local governments. The findings challenge the hypothesis that the shared tax base would be overused in a common-pool resource scenario. Instead, the empirical results show that the issuance of general obligation bonds is more likely in jurisdictions where counties and school districts make more intensive use of the property tax. These findings highlight the importance of the signals local governments receive from their overlapping neighbors regarding voters’ demand for additional public spending.