Evaluation of the Ability to Apply Near-Infrared Spectroscopy on Direct Assay of Acyclovir in Tablets

This paper aimed at developing a simple and fast approach using chemometrics processing for direct assay of acyclovir in tablets by NIR （near infrared） spectroscopy in diffuse reflectance mode. In making trials with 5 different tablet matrices, the experimental results showed that regardless the matrix variation, it was always possible to construct a quantitative model with suitable linear range, accuracy and precision for direct assay of acyclovir in tablet from NIR spectra. Therefore, the approach used in this study was suitable for on-site fast assay of APIs in tablets during manufacturing process or in post-marketing surveillance of drug quality.

Preparation and Preliminary Identification of Fluorescein Labeled Monoclonal Antibody against Canine Distemper Virus

[Objective] The aim of the present study was to develop a direct immunofluorescence method for the diagnosis of canine distemper （CD） with FITC-conjugated monoclonal antibodies （FITC-McAb）.[ Metbod] The McAb against CDV, designated as CE3, was purified with protein G and labeled with FITC through agitation method. After purification and identification, the optimal working concentration of FITC-labeled CE3 was determined. Then 61 clinical samples of suspected canine distemper were detected by direct immunofluorescence assay. [ Result] The absorption test, blocking test and specificity test showed that the labeled antibody had high specificity and sensitivity, but didn＇t have cross reaction with canine parvovirus （CPV）, canine parainfluenza virus （CPIV）, canine adenovirus （CAV） and rabies virus （RV）. The optimal working concentration was 1：80. The positive rate of clinical suspected samples was 48%. [ Conclusion] The direct immunofluorescence assay developed in this study was rapid, specific and convenient, and had great significance for the early diagnosis of canine distemper.

Studies on the QSAR of ACE Inhibitory Tripeptides with Proline as C-Terminal and Determination Inhibitory Activities

A database of 38 tripeptides with C-terminal proline was constructed to study QSAR of ACE inhibitory peptides. The model was established using PLS based on the three z-scores of 20 coded amino acids. The prediction ability of tripeptides model was improved with proline as terminal. The coefficient of determination(R2) and the cross validated coefficient(Q2LOO) of the model are 0.856 and 0.782 respectively. According to the model, two potential ACE inhibitory tripeptides IIP and IVP were synthesized. Their IC50(inhibitor concentration that reduced enzyme activity by 50%) were proved to be 1.58 and 1.39 μM respectively by direct spectrophotometric measurement, and they are very close to the predicted value by the model.

Pulmonary Tuberculosis in HIV-infected Patients Presenting with Normal Chest Radiograph and Negative Sputum Smear

Deaths due to Tuberculosis （TB） are high among the TB-HIV co-infected patients. Among PLHIV most of the instances the sputum smear is found to be negative for MTb. Chest X-rays also don＇t yield much diagnostic value mainly due to the advanced immune suppressed condition. This study makes an attempt to find out the utility of alternate staining methods such as Light Emitting Diode （LED）, Fluorescent Microscopy （FM） and solid culture in resource limited settings for effective diagnosis of TB among PLHIV. 2 sputum samples were collected from 102 successive presumptive TB cases, whose smear microscopy and X-Ray were negative for MTb among PLHIVs visiting ICTC at MGM hospital, Warangal, Telangana State, India. All the 102 samples were repeated with ZN microscopy and X-ray. Additionally LED and FM microscopy procedures were conducted with the NALC-NAOH concentration method. All the samples were inoculated on LJ medium for solid culture and all the positive cultures were subjected for biochemical test to identify phenotypic appearance, nitrate reduction, niacin and PNB susceptibility test for all the first line anti TB drugs as per standard guidelines. Samples found positive on microscopy were cross checked with Line probe assay （LPA）. All the 102 samples collected showed negative for MTb on ZN technique and negative for pulmonary TB on chest X-rays. 15 samples were positive for MTb both on LED and FM. LPA reconfirmed the MTb in all the 15 samples tested with 11 sensitive for both INH and Rifampicin, 3 INH mono resistant and I Rifmono resistance patterns. Of the 102 inoculations in LJ medium, 25 culture inoculations were positive for MTb growth and also were confirmed as MTb strains based on morphological, biochemical test and growth was seen after 4th week of inoculation. Of the 25 culture positives 20 were sensitive for INH and Rif, 4 INH mono resistant and 1 resistant to all first line anti TB drugs. In smear negative and chest X-ray negative presumptive TB cases, especially in immune compromised groups such as PLHIV, it is found to be useful to subject the sputum samples to LED and FM methods and at least solid culture wherever available. These methods clearly demonstrated additional yield over conventional ZN staining which can be recommended especially in the settings where high throughput equipment such as Xpert MTB/RIFor liquid culture is not available. These proactive measures can help in early diagnosis of TB which in turn can reduce mortality due to TB among PLHIV and break the chain of transmission of TB. Recommendations： Technology such as LED or FM microscopy can be advised for effective diagnosis of TB among Presumptive TB cases in PLHIV in settings where Xpert MTB/RIF is not available.