Fluorescence and chemiluminescence analyses of amino acids and thiols derivatized with 2-fluoro-4,5-diphenyloxazole (DIFOX) and 2-chloro-4,5-bis(p-N,N-dimethylaminosulphonylphenyl)oxazole (SAOX-Cl) were investigated. Thirteen diphenyloxazole (DIOX)-derivatized amino acids were separated within 38 min by a linear gradient elution from 100% A [0.05 M phosphate (pH 7.0): CH3CN (75:25)] to 100% B [0.05 M phosphate (pH 7.0):CH3CN (1:1)] over 30 min and an isocratic elution of 100% B for 30 min. The detection limits (S/N = 2) with fluorescence detection were in the range of 19-64 fmol. Thiols derivatized with SAOX-Cl were separated by an isocratic elution using 0.1 M H3PO4:CH3CN (65:35) and detected fluorimetrically. The detection limits (S/N = 2) of reduced glutathione, N-acetylcysteine, 2-mercaptopropionylglycine, cysteine, homocysteine and captopril were 1.2, 1.5, 1.9, 5.7, 6.4 and 7.9 fmol, respectively. Peroxyoxalate chemiluminescence (CL) intensities of sulphonyl-5-N,N-dimethylaminonaphthalene (DNS), SAOX and DIOX derivatives were compared using three different oxalate esters (DFPO, TCPO and TDPO) by flow injection analysis. The relative chemiluminescence intensity (RCL) of SAOX-proline and DIOX-proline were 76-80% and 19-25% of DNS-proline (100%), respectively. Other SAOX and DIOX derivatives showed lower CL intensities (< 12%). Extremely low CL intensities were obtained for the fluorescent tagging reagents (< 0.11%) and their hydrolysis products (< 0.80%). Secondary amino acids and peptides, derivatized with DIFOX in aqueous media at room temperature for 1 h, were detected using DFPO/H2O2. TCPO/H2O2 and TDPO/H2O2 after separation by high performance liquid chromatography.(ABSTRACT TRUNCATED AT 250 WORDS)

Amines↗

PubMedDate not supplied

Identification of inosine as an endogenous modulator for the benzodiazepine binding site of the GABAA receptors.

Previously we have reported the presence of endogenous ligands that are involved in the regulation of the binding of muscimol to the GABA binding site of the GABAA receptors. Here, we report the presence of multiple forms of endogenous ligands in the brain which modulate the binding of flunitrazepam (FNZP) to the benzodiazepine (BZ) binding site of the GABAA receptor. Furthermore, one of the endogenous ligands for the BZ receptors, referred to as EBZ, has been identified as inosine based on the following observations: (1) standard inosine and the EBZ have identical NMR and UV spectra; (2) the elution profile of inosine and the EBZ from a HPLC column are indistinguishable, and (3) inosine and the EBZ show identical activity in inhibiting [3H]FNZP binding.

Animals↗

PubMedDate not supplied

Conducting HIV outreach and research among incarcerated drug abusers: a case study of ethical concerns and dilemmas.

This case involves the examination of an ethically problematic event that arose while we were conducting an outreach/early intervention research demonstration project targeted at women who exchange sex for drugs. Subjects were drug abusers--primarily crack-cocaine smokers--recruited by outreach workers on "the street" and in jail. Participants were offered counseling, HIV and syphilis screening, and risk-reduction education. A woman who was a jail inmate tested positive for HIV. In order to obtain medical and other assistance, she would have to reveal her serostatus to jail officials. This could result in isolation and the possibility of harm from others in the jail once the information about her circulated. The case highlights the problems inherent in HIV testing of incarcerated drug abusers, especially in low HIV seroprevalence areas. We recommend that a community empanel a committee composed of substance abuse treatment and medical professionals, civil rights advocates, criminal justice personnel, and ethicists to formulate humane and effective policy in light of its drug abuse and HIV problems and its resources.

AIDS Serodiagnosis↗

PubMedDate not supplied

Crack-cocaine use and health status as defined by the SF-36.

The Medical Outcomes Study Short Form 36 (SF-36) was administered to 443 not-in-treatment, crack-cocaine smokers to explore the relationship between frequency of crack, alcohol, and tobacco use, addiction to these drugs, and health status. The reliability of the SF-36 with crack smokers was also assessed. Statistically significant, negative associations emerged between frequency of crack use and all SF-36 subscales except physical functioning. There were not significant associations between frequency of alcohol or tobacco use and any SF-36 subscale. Self-assessed addiction to crack was strongly and negatively associated with all SF-36 subscales: alcohol and tobacco addiction were also negatively associated with health status, but not to the degree of crack. The SF-36 produces reliable data on the health status of crack users and, as such, may have a useful role in assessments involving crack-using populations.

Adult↗