A practical approach to determination of laboratory GC-MS limits of detection.

Determination of limit of detection (LOD) values in a forensic laboratory serves a fundamental forensic requirement for assay performance. In addition to demonstrating assay capability, LOD values can also be used to fulfill certification requirements of a high-volume forensic drug laboratory. The LOD was defined as the lowest concentration of drug that the laboratory can detect in a specimen with forensic certainty at a minimum of 85% of the time. Overall batch acceptance criteria included acceptable quantitation of control materials (within 20% of target), acceptable chromatography (symmetry, peak integration, peak shape, peak, and baseline resolution), retention time within +/-1% of the extracted standard, and mass ion ratios within +/-20% of the extracted standard mass ion ratios. Individual specimen acceptance criteria were the same as the batch acceptance criteria excluding the quantitation requirement. Data were collected from all instruments on different runs. A minimum of ten data points was required for each certified instrument, and a minimum of 85% of data points was acceptable. Quantitation within +/-20% of the LOD concentration was not required, but acceptable mass ratios were required. Data points with poor chromatography (internal standard failed mass ratios; interference of the baseline, for example, shoulders; asymmetry; and baseline resolution) was omitted from the acceptable rate calculation. Data points with good chromatography with failed mass ion ratios were included in the acceptable rate calculation. With these criteria, we established the following LODs: 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid, 2 ng/mL; benzoylecgonine, 5 ng/mL; phencyclidine, 2.5 ng/mL; amphetamine, 150 ng/mL; methamphetamine, 100 ng/mL; codeine, 500 ng/mL; and morphine, 1000 ng/mL.

Attendance patterns in general practice.

OBJECTIVE: To determine the completeness of data acquired previously on the attendance patterns of patients visiting three general practices and the exclusivity of attendance at these practices. DESIGN: A retrospective comparison of attendance data with data extracted from the Health Insurance Commission database. Three study practices were investigated to give a rough cross-section of general practice in Western Australia. RESULTS: Eighty-nine per cent of patients and 92% of services recorded in our earlier study were also recorded by the HIC, with 31% of patients also attending another general practice during the six months, mostly only once or twice. However, there was considerable variation between practices in data match and attendance at other practices. CONCLUSIONS: We found a high level of completeness of data. Sixty-nine per cent of patients attended no other practice during the six months, indicating that doctors in the study practices have some opportunity to provide continuity of care to their patients. The implications for patients' needs and doctors' resources of variations in attendance patterns need to be examined further.

A history of sexually transmitted diseases in Thailand: policy and politics.

This paper provides a brief history of sexually transmitted diseases (STDs) in Thailand. The presentation is divided into three main sections: the period up to the 1930s; the period from the 1930s until the end of the early 1980s; and the period from the early 1980s until the present, the so-called 'AIDS Era'. The discussion in each of these sections focuses, as far as sources permit, on the epidemiological picture, as well as describing public and official responses to these diseases. In the final part of the paper consideration is given to these findings in relation to the present situation in Thailand regarding the HIV/AIDS epidemic.

PIP: Sexually transmitted diseases (STDs) have afflicted Thais since premodern times. Medical descriptions of STDs in the 1800s addressed the link between prostitution and STDs. During 1910-1925, STD rates in Bangkok were estimated to be 75-80% of adult males. Movement of people across the borders of China and Laos contributed to the spread of STDs in the early 1900s, as it does today. In 1908, Thailand enacted a law which required all female prostitutes to undergo a regular medical examination to become registered. It also set up brothels. Policymakers wanted to prevent STD transmission from prostitutes to men. They did not address male clients' responsibility. They were not concerned with the women. This official pattern persists. Beginning in 1930, Bank Rak Hospital housed the Control Unit to Reduce Venereal Diseases. The 1908 law was still in force during 1930-1949 despite attempts to ban sex work. In 1952, the UN provided Thailand assistance for STD education for students. During 1950-1965, businessmen and government officials profited from prostitution. In 1960, Thailand passed a law banning prostitution. In the late 1960s and early to mid 1970s, US military personnel in Thailand sought prostitutes, resulting in expansion of illegal prostitution. At the same time, Thailand was promoting itself as a tourist destination. One high-profile deputy premier, banker, and businessman asked provincial governors to promote sex tourism. In the mid 1980s, STDs spread rapidly in Thailand. The first AIDS case was in 1984. In 1987, there were 8 AIDS cases and 112 HIV-positive cases, most of whom were gay males (50% foreigners). It took just a few months for about 100,000 IV drug users to be HIV infected. In one year, the HIV infection rate among prostitutes in Chiang Rai Province jumped from 1 to 37%. HIV/AIDS is expected to reach all population groups by 2000. The official response to the AIDS epidemic was first denial, then active monitoring and public education, and now increased community support for sufferers and multisectoral development programs.

HIV infection. Helping adolescents choose safer behaviors.

Although adolescents comprise only 1% of the diagnosed cases of acquired immune deficiency syndrome (AIDS), the risk of human immunodeficiency virus (HIV) infection among this group should not be underestimated. This article discusses how adolescents' behaviors place them at risk for HIV infection. One educational program is described that illustrates an innovative approach to use with adolescents. Nurses who use the Relationship Safety and Vigilance Plan can assist individual adolescents to assess their interpersonal relationship patterns to establish goals and reduce impulsive or destructive behaviors.