1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => Controlled
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => FreeToRead
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
PT  - JOURNAL ARTICLE
AU  - Chong, W K
AU  - Paley, M
AU  - Wilkinson, I D
AU  - Hall-Craggs, M A
AU  - Sweeney, B
AU  - Harrison, M J
AU  - Miller, R F
AU  - Kendall, B E
TI  - Localized cerebral proton MR spectroscopy in HIV infection and AIDS.
DP  - 1994 Jan 01
TA  - American Journal of Neuroradiology
PG  - 21--25
VI  - 15
IP  - 1
4099  - http://www.ajnr.org/content/15/1/21.short
4100  - http://www.ajnr.org/content/15/1/21.full
SO  - Am. J. Neuroradiol.1994 Jan 01; 15
AB  - PURPOSE To document differences in the cerebral proton MR spectra of patients with early and late stages of human immunodeficiency virus (HIV) infection. METHOD We studied the relative N-acetyl-aspartate (NAA) levels by localized proton spectroscopy of the parietooccipital region of the brain in 43 HIV-seropositive patients, including 26 with an acquired immunodeficiency syndrome (AIDS)-defining diagnosis, and in eight control subjects. RESULTS Reduced relative NAA levels were shown in those HIV-1-seropositive patients: 1) with AIDS against HIV-1-seropositive patients without AIDS (P &amp;lt; .04); 2) with HIV-1-associated cognitive/motor complex against neurologically healthy patients (P &amp;lt; .007); 3) with encephalopathic changes on MR against those with normal imaging (P &amp;lt; .001); and 4) on follow-up against their results on initial study (P &amp;lt; .03). CONCLUSIONS By clinical (Centers for Disease Control classification) and radiologic (MR evidence of white-matter disease) criteria indicating late-stage HIV infection, reduced relative levels of NAA have been demonstrated. Spectroscopic abnormalities can be quantitatively tracked with time. This paper demonstrates the clinical use of detecting NAA as a putative in vivo measure of the neuronal loss that has been demonstrated in postmortem studies of patients with AIDS. This neuronal loss, which is believed to underlie the HIV-1-associated cognitive/motor complex, is thought to be attributable directly or indirectly to the presence of HIV in the brain. Proton spectroscopy may serve as a quantitative noninvasive indicator of this aspect of cerebral involvement in HIV disease.