Analysis of glutathione, glutathione disulfide, cysteine, homocysteine, and other biological thiols by high-performance liquid chromatography following derivatization by n-(1-pyrenyl)maleimide.

The compound N-(1-pyrenyl)maleimide (NPM) reacts with free sulfhydryl groups to form fluorescent derivatives. A new method for measurement of glutathione and other biological thiols utilizing reverse-phase high-performance liquid chromatography to separate and quantify these derivatives is described. Separation and quantification of glutathione, cysteine, homocysteine, cysteinylglycine, and gamma-glutamylcysteine derivatives are achieved. The method allows for the measurement of glutathione disulfide by masking free glutathione with 2-vinylpyridine, reducing glutathione disulfide with glutathione reductase, and measuring the resulting glutathione. Coefficient of variations for the various thiols measured by the NPM method range from 1.5 to 8.8%. The lower detection limit is around 50 fmol of glutathione. NPM derivatives are shown to be stable for 2 months at 4 degrees C. Between 94.2 and 97.2% of glutathione and/or glutathione disulfide added to a sample is recovered using the NPM method. The NPM method is compared to the monobromobimane high-performance liquid chromatography method and the Tietze assay by measuring glutathione in homogenates from five different cell lines. The newly developed method offers some advantages over the currently accepted techniques, including specificity, speed, sensitivity, and ease of use.

HIV seropositivity as a major risk factor for suicide in the general hospital.

The purpose of this study was to assess the suicide rate in people infected with the human immunodeficiency virus (HIV) in the general hospital population. A retrospective study of 2,363 psychiatric consultations was done in 1989 and 1990 at an urban municipal teaching hospital in New York City. The sample included 2,363 patients admitted to adult general care from January 1, 1989, to December 31, 1990, for whom consultations were requested from the consultation-liaison psychiatry service. Suicidal behavior was the reason for consultation in 21.8% of HIV-positive persons and in 19.8% of persons with acquired immunodeficiency syndrome. It was the reason for consultation in only 13.9% of persons with unknown HIV serostatus. This difference is statistically significant. The authors conclude that HIV seropositivity may be a significant risk factor for suicide in the general hospital patient population.

Malaria--the mime revisited: fifteen more years of experience at a New York City teaching hospital.

PURPOSE AND PATIENTS: A previous review of The New York Hospital experience with malaria during 1968 to 1975 summarized clinical and parasitologic features in 24 travelers and highlighted deficiencies in both chemoprophylaxis and diagnosis. To extend this original study, we describe 86 patients with malaria seen at the same hospital during the subsequent 15 years. RESULTS: Eighty patients were infected with a single Plasmodium species, and 60% had Plasmodium falciparum infection primarily acquired in Africa. Eighty percent were symptomatic while in or within 1 month of departing the malarious region. All patients described a history of fever; however, 25% were afebrile at the initial hospital visit. A normal white blood cell count, thrombocytopenia, and an increased lactate dehydrogenase level were common laboratory results. Seventy-five percent of non-native travelers took either no or inadequate chemoprophylaxis. Malaria was not suspected in 16 of the 20 (80%) patients seen initially by local New York City physicians but was initially suspected and confirmed in 49 of 54 (91%) patients first seen at The New York Hospital. CONCLUSION: In comparison to our 1968 to 1975 experience, these updated results indicate no improvement in either the use of appropriate chemoprophylaxis or the capacity to properly diagnose malaria in the community. Improvement is still clearly needed in both areas.