Postnatal development of energy metabolism in the rat brain.

The activities of cytochrome c oxidase and F0F1-ATPase as well as the content of cytochromes cc1, aa3, and b were investigated in free brain mitochondria in the course of postnatal development and aging. The results show an increase of Vmax of both enzymes during postnatal development (between day 5 and 30). During the following phase ending at the age of 6 months, a decrease of F0F1-ATPase and cytochrome c oxidase activity occurs. From 6 to 12 months of age the activity of these enzymes did not change. The KM for both enzymes remained unchanged during the whole period observed. The content of cytochromes increased from the low values found in young rats, reached the highest values at around one month, and decreased till the age of 3 months. Later, their content in brain mitochondria did not markedly change. Our results suggest that the metabolic maturation of brain mitochondria differs in several aspects from the same process in other tissues, mainly in the time course. This is probably due to the unique role of neural tissue in the organism.

Human immunodeficiency virus Type 1 (HIV-1) plasma virus load and markers of immune activation among HIV-infected female sex workers with sexually transmitted diseases in Abidjan, Côte d'Ivoire.

Plasma levels of human immunodeficiency virus type 1 (HIV-1) RNA and markers of immune activation were compared among HIV-1-infected female sex workers (FSWs) with (n=112) and without (n=88) sexually transmitted diseases (STDs) in Abidjan, Côte d'Ivoire. After adjustment for CD4+ T cells, the median virus load was 2.5-fold higher among HIV-seropositive FSWs with STDs than among those without an STD (P=.053). Median virus load was higher for FSWs with a genital ulcer (P=.052) or gonorrhoea (P=.058) than for FSWs without any STD. Median levels of markers of immune activation (CD38 and HLA-DR on CD8+ T cells, soluble tumor necrosis factor-alpha receptor II, and beta(2)-microglobulin) tended to be elevated, albeit nonsignificantly, among FSWs in the STD group. These findings have important public health implications in elaborating strategies for decreasing disease progression and transmission of HIV among FSWs.

Dual infection with human immunodeficiency virus type 1 and type 2: impact on HIV type 1 viral load and immune activation markers in HIV-seropositive female sex workers in Abidjan, Ivory Coast.

To determine the impact of dual infection with HIV-1 and HIV-2 on HIV-1 viral load and markers of immune activation among HIV-seropositive FSWs in Abidjan, we analyzed blood samples obtained from consenting HIV-seropositive FSWs attending a confidential clinic between September 1996 and June 1997 in Abidjan. Among HIV-1 and HIV-2 dually seropositive FSWs, polymerase chain reaction (PCR) testing with HIV-1 and HIV-2 primers was used to differentiate between FSWs who were PCR positive only for HIV-1 and those positive for both HIV-1 and HIV-2 (dually infected). Of the 203 FSWs, 151 (74%) were HIV-1 seropositive only (median age, 26 years), 4 (2%) were HIV-2 seropositive, and 48 (24%) were dually seropositive (median age, 30 years). Of the 48 dually seropositive FSWs, 33 (69%) were dually infected and 15 (31%) were dually seropositive. Median CD4+ T cell counts per microliter were not significantly different among the three groups (525 for HIV-1 positive only, 502 for dually infected, and 416 for dually seropositive) (p = 0.14). Median viral load (log10 copies/ml) was not significantly different among the HIV-1-only FSWs (4.8 log10 copies/ml) compared with the 32 dually infected FSWs (4.6 log10 copies/ml) and 14 dually seropositive FSWs (4.7 log10 copies/ml; p = 0.95). Median levels of HLA-DR immune activation were increased in both CD4+ and CD8+ T cells for the dually infected (n = 27) FSWs compared with those infected with HIV-1 only (n = 123) (p = 0.019 and p = 0.01, respectively). Dual infection does not appear to influence levels of HIV-1 viral load in vivo. However, levels of HLA-DR are higher among FSWs dually infected with HIV-1 and HIV-2 than among those infected with HIV-1 only.

Quantification of RNA in HIV type 1 subtypes D and G by NucliSens and Amplicor assays in Abidjan, Ivory Coast.

We have compared the performance of the NucliSens and the standard and modified HIV Monitor assays to quantify HIV-1 RNA plasma viral load in 12 tuberculosis patients infected with HIV-1 env subtype D (n = 3) and env subtype G (n = 9) in Ivory Coast. RNA was quantified in all nine subtype G specimens by the modified Amplicor HIV Monitor (mean, 4.6 log10 copies/ml; range, 3.1-6.3 log10/ml), in seven specimens by NucliSens (mean, 4.4 log10 copies/ml; range, 2.7-5.5 log10 copies/ml), and in 6 specimens by the standard Amplicor HIV Monitor assay (mean, 4.2 log10 copies/ml; range, 3.5-5.0 log10 copies/ml). All three subtype D samples were amplified by both the modified Amplicor HIV Monitor (mean, 4.5 log10 copies/ml; range, 3.8-5.1 log10 copies/ml) and NucliSens (mean, 3.8 log10 copies/ml; range, 2.8-5.0 log10 copies/ml); two samples were quantified by the standard Amplicor HIV Monitor assay (mean, 3.0 log10 copies/ml; range, 2.4-3.6 log10 copies/ml). Our preliminary results suggest that the modified Amplicor HIV Monitor can accurately quantify HIV-1 RNA viral load in persons infected with subtype D and G strains.

Evaluation of HIV serial and parallel serologic testing algorithms in Abidjan, Côte d'Ivoire.

OBJECTIVE: To evaluate HIV serologic testing algorithms based on a combination of three enzyme linked immunosorbent assays (ELISA) for the confirmation of HIV infection in Abidjan, Côte d'Ivoire, where HIV-2 and HIV-1 non-B subtypes are prevalent. METHODS: A total of 1069 human sera with known serologic status, in addition to a seroconversion and low titer antibody panel were initially tested by six ELISA to determine the sensitivity, specificity and delta values of the assays. On the basis of the performance of the assays, three ELISA (Enzygnost, ICE 1.0.2, and Vironostika) were selected for use in a parallel and serial testing algorithm in analyzing 8283 consecutively collected sera. In the parallel testing algorithm, sera concordantly reactive or non-reactive by Enzygnost and ICE 1.0.2 were considered as true positive or true negative, respectively. In the serial algorithm, sera reactive by Enzygnost were retested by ICE 1.0.2. Sera with discordant results were tested by Vironostika, and the results was considered definitive. All reactive sera, plus a random sample of negative sera were tested for confirmation by Peptilav. In addition, a random sample of reactive sera was tested by Western blot. RESULTS: All ELISA had 100% sensitivity; specificities ranged from 96.8 to 100%. Positive and negative delta values of the ELISA were high (range, 6.89 to 46.07 and -2.05 to -5.75, respectively). Of the 8283 sera, 2054 were considered true positives and were correctly classified by the parallel testing algorithm (sensitivity, 100%). Of the 6229 true negative sera, 6226 were negative by the parallel testing algorithm (specificity, 99.95%). The sensitivity of the serial algorithm was 99.96%, and specificity was 99.95%. None of the 250 concordant ELISA-negative sera in the algorithm that were randomly tested in Peptilav was positive; similarly, all of the 103 concordant ELISA-positive sera were confirmed by Western blot. The three-ELISA algorithm resulted in reagent cost-savings of at least 50% compared with the Peptilav-based algorithm. CONCLUSION: These results suggest that a combination of ELISA using different principles or antigens in a serial or parallel algorithm is an efficient and cost-effective alternative to the standard algorithm in areas where HIV-1 and HIV-2 are prevalent.

Comparison of NucliSens and Amplicor monitor assays for quantification of human immunodeficiency virus type 1 (HIV-1) RNA in plasma of persons with HIV-1 subtype A infection in Abidjan, Côte d'Ivoire.

We compared the sensitivity and accuracy of the NucliSens assay and those of both the standard and modified (addition of a new primer set, primer mix 1, supplied by Roche) Amplicor HIV Monitor assays to quantify human immunodeficiency virus type 1 (HIV-1) RNA in persons infected with HIV-1 subtype A in Abidjan, Côte d'Ivoire. Seventy-one plasma samples from HIV-1-seropositive persons at different stages of HIV infection and 15 samples from HIV antibody-negative persons were analyzed. The HIV-1 genetic subtype was determined either by DNA sequencing or by a restriction fragment length polymorphism assay. Of the 71 samples, 70 (98%) were subtype A and 1 was subtype G. Of the 70 subtype A samples, the proportion of RNA-positive plasma samples and mean HIV-1 RNA levels were significantly higher by the modified HIV Monitor assay (n = 67 [96%]; mean RNA levels, 5.2 log10 HIV-1 RNA copies/ml) than the NucliSens assay (n = 56 [80%]; 4.3 log10 HIV-1 RNA copies/ml) or the standard HIV Monitor assay (n = 44 [63%]; mean RNA levels, 3.8 log10 HIV-1 RNA copies/ml) (all P values were <0.05). The HIV-1 RNA levels by the modified HIV Monitor assay correlated significantly with those by the NucliSens assay (r = 0.76; P < 0.001) and the standard HIV Monitor assay (r = 0.57; P < 0.001), as did the RNA levels by the NucliSens and the standard HIV Monitor assays (r = 0.60; P < 0. 001). Lower CD4 cell counts were significantly correlated with higher HIV-1 RNA levels by all three assays (r = -0.47 for the NucliSens assay, -0.45 for the standard HIV Monitor assay, and -0.62 for the modified HIV Monitor assay). These results indicate that the modified HIV Monitor assay has the highest sensitivity and efficiency at quantifying the levels of RNA in persons infected with HIV-1 subtype A and thus constitutes a valuable tool for the monitoring of RNA levels in areas of Africa were HIV-1 subtype A is predominant.

Field evaluation of a combination of monospecific enzyme-linked immunosorbent assays for type-specific diagnosis of human immunodeficiency virus type 1 (HIV-1) and HIV-2 infections in HIV-seropositive persons in Abidjan, Ivory Coast.

Serologic distinction between human immunodeficiency virus type 1 (HIV-1) and HIV-2 infection is made difficult because of the cross-reactivity and high cost of existing differentiation assays. An evaluation of a strategy based on a combination of monospecific enzyme-linked immunosorbent assays (ELISAs) (CME), was carried out in Abidjan, Ivory Coast, where both HIV-1 and HIV-2 are present, to determine its accuracy and cost-effectiveness. A total of 1,608 (428 HIV-1-positive, 361 HIV-2-positive, 371 dually HIV-1 and HIV-2 [HIV-D] reactive, and 448 HIV-negative) sera that had been serotyped by a line immunoassay (Peptilav) were tested retrospectively by an HIV-1-monospecific (Wellcozyme HIV Recombinant ELISA) and an HIV-2-monospecific (ICE*-HIV-2) assay. The CME strategy gave concordant results for all of the 428 sera scored as HIV-1 by Peptilav. Of the 361 sera scored as HIV-2 by Peptilav, 316 (87.5%) were scored as HIV-2 by CME; the remaining 45 sera were positive by both monospecific ELISAs (mean optical density ratios, 1.36 for Wellcozyme and 11.30 for ICE*-HIV-2) and were classified as HIV-D by CME. Of the 371 sera classified as HIV-D by Peptilav, 344 (92.7%), 21, and 6 were scored as HIV-D, HIV-1, and HIV-2, respectively, by CME. Additional testing of the discrepant samples by two HIV differentiation assays (RIBA and INNO-LIA) gave results that agreed with those by CME for most of the sera. In addition, 267 other sera were tested prospectively by both CME and Peptilav. In the prospective evaluation, CME results agreed with those by Peptilav for all 106 HIV-1 sera and 40 of the 41 HIV-2 sera. However, of the 120 sera scored as HIV-D by Peptilav, 69 (57.5%), 47 (39.2%), and 4 (3.3%) were scored as HIV-D, HIV-1 only, and HIV-2 only, respectively, by CME. All 47 samples scored as HIV-1 by CME and two of four HIV-2 sera gave concordant results by RIBA, whereas 29 of 47 sera scored as HIV-1 by CME and all four HIV-2 sera gave concordant results by INNO-LIA. The reagent cost for the CME strategy was 59% lower than the cost of the Peptilav strategy. These results suggest that a combination of highly sensitive and specific commercially available monospecific ELISAs is a reliable and cost-effective strategy for type-specific serodiagnosis of HIV-1 and HIV-2 infections in HIV-seropositive persons and therefore represents a recommended strategy in areas where both HIV-1 and HIV-2 are endemic.