Asymptomatic reproductive tract infections/sexually transmitted infections among HIV positive women.

This study aims to highlight the importance of screening all HIV positive women for various reproductive tract infections/sexually transmitted infections (RTIs/STIs) irrespective of symptoms and to determine its occurrence in asymptomatic HIV positive women. Relevant specimens were collected for diagnosis of various RTIs/STIs. STIs were diagnosed in nearly one-third of the HIV positive asymptomatic patients which is quite high. The national strategy for STIs/RTIs control misses out large number of asymptomatic RTIs/STIs in HIV positive women which is responsible for silently transmitting these infections in the community. So this strategy should be modified to include screening of all HIV positives women irrespective of symptoms of STIs/RTIs.

Spectrofluorimetric determination of 5-fluorouracil by fluorescence quenching of 9-anthracenecarboxylic acid.

Photo-induced intermolecular electron transfer (PET) interaction between excited singlet (S(1)) state of 9-anthracene carboxylic acid (9-ANCA) and DNA bases of pyrimidines as uracil and 5-fluorouracil (5-FU) has been studied in water and ethanol solutions using steady-state fluorescence spectroscopy. The intensity of all emission bands of 9-ANCA was quenched in presence of uracil and 5-FU by electron transfer reaction without formation of an exciplex. It was found that uracil and 5-fluorouracil acts as effective electron donors and simultaneously quench the fluorescence of electron-accepting sensitizer 9-ANCA. The quenching by diffusion-controlled rate coincides well with the dynamic Stern-Volmer correlation. The bimolecular quenching rate constant (k(q)(ss)) and electron transfer rate constant (k(et)) observed are seen to be much higher for 5-fluorouracil than those for uracil. The thermodynamic parameters estimated by using the Rehm-Weller equation were used to propose a suitable mechanism for PET occurring between uracils and 9-ANCA. The proposed method was used to determine 5-fluorouracil from pharmaceutical samples with satisfactory results. The technique is more selective, sensitive and relatively free from coexisting substances.

Interaction between felodipine and bovine serum albumin: fluorescence quenching study.

The fluorescence quenching spectrum of bovine serum albumin (BSA) was investigated in the presence of felodipine (FLD) by spectroscopic methods including fluorescence spectroscopy and UV-Vis absorption spectroscopy. Stern-Volmer quenching was successfully applied and the corresponding thermodynamic parameters, namely enthalpy change (DeltaH), free energy change (DeltaG) and entropy change (DeltaS) at different temperatures (304, 314 and 324 K) were calculated according to the Van't Hoff relation. This revealed that the hydrophobic interaction plays a major role in stabilizing the complex. The fluorescence spectrum of BSA was studied in presence of various concentrations of SDS surfactant. The distance (r) between donor (BSA) and acceptor (FLD) was obtained according to fluorescence resonance energy transfer (FRET). The synchronous fluorescence spectroscopy was used to investigate the effect of FLD on BSA molecule. The result shows that the conformation of BSA was changed in the presence of felodipine.