AIDS dementia may be linked to metabolite of tryptophan
Article Abstract:
Researchers have recently become interested in the relationship between quinolinic acid, a metabolite, or breakdown product, of tryptophan, and the neurological damage that is often present in people infected with human immunodeficiency virus (HIV, the virus associated with AIDS). Quinolinic acid can induce seizures, is activated by interferon gamma, and increases in concentration when infection is present. However, it increases even more (up to 1,000-fold) in patients with AIDS dementia complex. At these high levels, the substance could bind to proteins that serve as receptors for N-methyl-D-aspartate, inactivating them, with deleterious effects on neural processing. In HIV-infected people, quinolinic acid levels have often been significantly elevated for a long time, and they are known to increase progressively as symptoms of dementia increase. As such, the substance can serve as a marker of disease progression. Its levels also rise in macaque monkeys infected with simian immunodeficiency virus, even while the monkeys remain asymptomatic. When levels rise 100-fold in infected monkeys, brain lesions can often be seen by magnetic resonance imaging techniques. Assessment of quinolinic acid levels, however, is technically difficult, in part because even high levels of the substance represent very small quantities, in an absolute sense. The enzyme responsible for catalyzing the conversion of tryptophan and quinolinic acid is indoleamine-2,3-dioxygenase (IDL), and it may be elevated by as much as 6,800 percent in infected macaques as compared with uninfected controls. IDL is apparently activated in tissues other than the liver, 'sucking away' tryptophan from that organ, and catalyzing the formation of great quantities of quinolinic acid. This knowledge raises hopes for a therapeutic agent that would block the production of quinolinic acid, thereby reducing or preventing AIDS dementia. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1990
User Contributions:
Comment about this article or add new information about this topic:
Cofactor question divides codiscoverers of HIV
Article Abstract:
The two men who discovered the virus associated with AIDS, human immunodeficiency virus (HIV), have long been in conflict with one another. Now, Robert Gallo (from the National Institutes of Health's National Cancer Institute) and Luc Montagnier (of the Pasteur Institute in Paris) disagree over whether other factors besides infection with HIV (cofactors) are necessary to produce AIDS. Gallo believes that HIV is the only cause of AIDS, while Montagnier expresses some doubt that HIV infection is both necessary and sufficient for the development of that syndrome. In Gallo's view, coinfection with human T cell leukemia virus type I (HTLV-I) or human herpesvirus type 6 (HHV-6) may accelerate the course of HIV's effects, but that, without HIV infection, AIDS will not develop. Montagnier holds that how HIV causes AIDS has not been characterized, and that another force, such as mycoplasma infection, may be responsible for the depletion of CD4-positive T cells seen in AIDS patients. Mycoplasma may enter cells that have been infected with HIV, where it potentiates HIV replication. This view would initiate treatment against viruses and mycoplasma, as well as boosting normal immune function. Gallo recognizes that HIV infection progresses faster if HTLV-I infection is also present, but points out that few patients in Europe and the US have this infection; thus, it cannot be considered a cofactor. HHV-6 infection, also known to damage CD4-positive T cells, is present in most people, and can not be considered a specific cofactor for AIDS. Evidence for Montagnier's position may come from results of treatments that inactivate mycoplasma species, currently lacking in clinicians' armamentaria. Gallo and Montagnier remain in full disagreement about the role of cofactors in the development of AIDS, as well as about many other issues. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1990
User Contributions:
Comment about this article or add new information about this topic:
Harassment linked to fraud, lawsuit alleges
Article Abstract:
Maureen Polsby has filed a suit against the NIH that alleges not only sexual discrimination but scientific fraud. Polsby says that when she rejected the advances of her supervisor, he gave her projects to other scientists and published papers containing data that Polsby says was never collected. She says she was assigned work that none of her male colleagues had to do. She says that when she filed an Equal Employment Opportunity complaint, a director at NIH decided that she could not use her two years at NIH to fulfill the requirements of her medical residency, as she had been promised. When she learned her supervisor had published a paper allegedly containing fraudulent data, she filed a fraud and racketeering suit against the NIH. Several individuals who took part in the study confirm that they did not participate in many of the tests described. Polsby's supervisor and officials at the NIH deny Polsby's accusations.
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1992
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: HIV-1 and Ebola virus encode small peptide motifs that recruit Tsg101 to sites of particle assembly to facilitate egress
- Abstracts: Uterine size and endometrial thickness and the significance of cystic ovaries in women with pelvic pain due to congestion
- Abstracts: Metipranolol: a new beta-blocker for glaucoma. A topical carbonic anhydrase inhibitor for glaucoma. A topical prostaglandin for glaucoma
- Abstracts: Success of reentry into anesthesiology training programs by residents with a history of substance abuse. Physician, cherish thyself: the hazards of self-prescribing
- Abstracts: Subcutaneous interferon alpha in the treatment of refractory condylomata. First-void urine testing for Chlamydia trachomatis by polymerase chain reaction in asymptomatic women