Rational application of adenosine deaminase activity in cerebrospinal fluid for the diagnosis of tuberculous meningitis.

PURPOSE: Tuberculous meningitis (TBM) is one of the most serious and difficult to diagnose manifestations of TB. An ADA value >9.5 IU/L has great sensitivity and specificity. However, all available studies have been conducted in areas of high endemicity, so we sought to determine the accuracy of ADA in a low endemicity area. METHODS: This retrospective study included 190 patients (105 men) who had ADA tested in CSF for some reason. Patients were classified as probable/certain TBM or non-TBM based on clinical and Thwaite's criteria. Optimal ADA cutoff was established by ROC curves and a predictive algorithm based on ADA and other CSF biochemical parameters was generated. RESULTS: Eleven patients were classified as probable/certain TBM. In a low endemicity area, the best ADA cutoff was 11.5 IU/L with 91 % sensitivity and 77.7 % specificity. We also developed a predictive algorithm based on the combination of ADA (>11.5 IU/L), glucose (<65 mg/dL) and leukocytes (≥13.5 cell/mm(3)) with increased accuracy (Se: 91 % Sp: 88 %). CONCLUSIONS: Optimal ADA cutoff value in areas of low TB endemicity is higher than previously reported. Our algorithm is more accurate than ADA activity alone with better sensitivity and specificity than previously reported algorithms.

Potential multifunctional inhibitors of HIV-1 reverse transcriptase. Novel [AZT]-[TSAO-T] and [d4T]-[TSAO-T] heterodimers modified in the linker and in the dideoxynucleoside region.

In an attempt to combine the anti-HIV-inhibitory capacity of nucleoside reverse transcriptase (RT) inhibitors (NRTI) and non-nucleoside RT inhibitors (NNRTI), several heterodimer analogues of the previously reported [AZT]-(CH(2))(3)-[TSAO-T] prototype have been prepared. In these novel series, other NRTIs, an expanded range of linkers with different conformational freedom and other attachment sites for these linkers on the base part of the NRTI analogue have been explored. Moreover, in order to circumvent the dependence of the NRTI moiety of the heterodimer on activation by cellular nucleoside kinases, novel heterodimers in which the NRTI is bearing a masked monophosphate group at the 5'-position are described. Among the novel heterodimers, several derivatives show a potent anti-HIV-1 activity, which proved comparable, or even superior, to that of the AZT heterodimer prototype. The nature of the NRTI was important for the eventual anti-HIV-1 activity. In particular, the d4T heterodimer derivative containing a propyl linker between the N-3 positions of the base of TSAO-T and d4T was approximately 5- to 10-fold more inhibitory to HIV-1 than the corresponding AZT heterodimer prototype.

Novel TSAO derivatives modified at positions 3" and 4" of the spiro moiety.

We have explored the introduction of different functional groups at positions 3" and 4" of the spiro moiety of TSAO-T. Alkylation of this spiro moiety afforded mixtures of N and/or C-alkylated derivatives, while acylation occurs, exclusively, on the amino group. Position 3" has been selectively functionalized by halogenation followed by Stille-cross coupling reaction with organostannanes under a variety of experimental conditions.

Novel series of [ddN]-[TSAO-T] heterodimers as potential bi-functional inhibitors of HIV-1 RT. Studies in the linker and ddN region.

Novel series of [ddN]-(CH2)n-[TSAO-T] heterodimers have been prepared and tested for their anti-HIV-1 and HIV-2 activity. The most active compound of this series was the [d4T]-(CH2)3-[TSAO-T] heterodimer (EC50 = 0.018 +/- 0.03 microM).