A validated high-performance liquid chromatography method for the determination of rifampicin and desacetyl rifampicin in plasma and urine

Objective: To standardize a high-performance liquid chromatography (HPLC) method for the determination of rifampicin (RMP) and its major metabolite desacetyl rifampicin (DRMP) in plasma and urine. Material and Methods: A simple, specific and sensitive HPLC method was developed for the determination of RMP and DRMP in plasma and urine. Separation in both was achieved by reversephase chromatography on a C18 column with a mobile phase composition of 0.05 M phosphate buffer: acetonitrile (55:45 v/v) at 254 nm. Results: The retention times of DRMP, RMP and Rifapentine (RPN), the internal standard were 2.9, 4.8 and 10.5 min respectively. The assay was linear from 0.25 to 15.0 μg ml-1 for plasma and 2.5 to 80.0 μg ml-1 for urine. Both intra-day and inter-day accuracy and precision data showed good reproducibility. Conclusion: The HPLC method described is sensitive, selective and linear for the wide range of concentrations for RMP and DRMP in plasma and urine. Thus, the method developed is well suited for the pharmacokinetic studies

Serum neopterin levels in HIV infected patients with & without tuberculosis.

Background & objective : Three categories of prognostic markers are best documented as having significance in relation to prognosis of HIV infection. These include HIV viral load, CD4 T-cell levels and plasma levels of soluble markers of immune activation. The plasma activation markers, like neopterin, tumor necrosis factor alpha (TNF-α), interleukins etc., are products of cytokine activity and represent immunologic changes throughout the body. There is not much information available on serum neopterin estimation in patients infected with both HIV and tuberculosis (TB), though neopterin levels are known to be elevated in pulmonary TB patients. In this study we attempted to correlate neopterin levels with the presence of tuberculosis in HIV infected and uninfected individuals and studied the changes after antituberculosis treatment. Methods : Serum neopterin concentrations were measured by high performance liquid chromatography (HPLC) in 25 HIV-seropositive (HIV-TB) and 10-seronegative (TB) patients with tuberculosis before, during and at the end of antituberculosis therapy (ATT). S-neo was also measured in 10 HIV-seropositive asymptomatic individuals and 10 healthy controls. The results were correlated with clinical, bacteriological and immunological status. Results : All TB patients regardless of HIV status had elevated s-neo concentrations at diagnosis, which declined gradually during treatment. Patients with HIV/TB with CD4 counts < 200/mm3 had the highest levels at baseline with a steep fall during treatment. The median level at the end of treatment was significantly higher in HIV/TB than in TB patients, despite clinical improvement and bacteriological clearance of Mycobacterium tuberculosis. HIV infected asymptomatic individuals had neopterin levels that were higher than healthy controls but lower than HIV-TB patients. Interpretation & conclusion : Serum neopterin levels are elevated in HIV-positive patients, with the highest levels in those with tuberculosis and CD4 counts < 200/mm3. Though the levels decrease with anti tuberculosis therapy, persistently elevated levels indicate progressive HIV disease and a poor prognosis

Serum neopterin levels in HIV infected patients with &#38; without tuberculosis

Background &#38; Objective: Three categories of prognostic markers are best documented as having significance in relation to prognosis of HIV infection. These include HIV viral load, CD4 T-cell levels and plasma levels of soluble markers of immune activation. The plasma activation markers, like neopterin, tumor necrosis factor alpha (TNF-alpha), interleukins etc., are products of cytokine activity and represent immunologic changes throughout the body. There is not much information available on serum neopterin estimation in patients infected with both HIV and tuberculosis (TB), though neopterin levels are known to be elevated in pulmonary TB patients. In this study we attempted to correlate neopterin levels with the presence of tuberculosis in HIV infected and uninfected individuals and studied the changes after antituberculosis treatment. Methods: Serum neopterin concentrations were measured by high performance liquid chromatography (HPLC) in 25 HIV-seropositive (HIV-TB) and 10-seronegative (TB) patients with tuberculosis before, during and at the end of antituberculosis therapy (ATT). S-neo was also measured in 10 HIV-seropositive asymptomatic individuals and 10 healthy controls. The results were correlated with clinical, bacteriological and immunological status. Results: All TB patients regardless of HIV status had elevated s-neo concentrations at diagnosis, which declined gradually during treatment. Patients with HIV/TB with CD4 counts &#60;200/mm3 had the highest levels at baseline with a steep fall during treatment. The median level at the end of treatment was significantly higher in HIV/TB than in TB patients, despite clinical improvement and bacteriological clearance of Mycobacterium tuberculosis. HIV infected asymptomatic individuals had neopterin levels that were higher than healthy controls but lower than HIV-TB patients. Interpretation &#38; Conclusion: Serum neopterin levels are elevated in HIV-positive patients, with the highest levels in those with tuberculosis and CD4 counts &#60;200/mm3. Though the levels decrease with anti tuberculosis therapy, persistently elevated levels indicate progressive HIV disease and a poor prognosis

Molecular docking of azole drugs and their analogs on CYP121 of Mycobacterium tuberculosis

The Mycobacterium tuberculosis genome codes for 20 different cytochromes. These cytochromes are involved in the breakdown of recalcitrant pollutants and the synthesis of polyketide antibiotics and other complex macromolecules. It has been demonstrated that CYP121 is essential for viability of the bacterium by gene knock-out and complementation studies. CYP121 could therefore be a probable target for the development of new drugs for TB. It has been widely reported that orthologs of CYP121 in fungi are inhibited by azole drugs. We evaluated whether these azole drugs or their structural analogs could bind to and inhibit CYP121 of M. tuberculosis using molecular docking. Six molecules with known anti-CYP121 activity were selected from literature and PubChem database was searched to identify structural analogs for these inhibitors. Three hundred and fifty seven molecules were identified as structural analogs and used in docking studies. Fifty three molecules were found to be scored better than the azole drugs and five of them were ranked among the top 12 molecules by two different scoring functions. These molecules may be further tested by in vitro experimentation for their activity against CYP121 of M. tuberculosis