OBJECTIVE: HIV-1 Drug Resistance Mutations (DRMs) among Immunological failure (IF) on NRTI based first-line regimens, Thymidine analogue (TA) - AZT & D4T and Non-Thymidine Analogue (NTA) -TDF; and predict viral drug susceptibility to gain vision about optimal treatment strategies for second-line.
METHODS: Cross-sectionally, 300 HIV-1 infected patients, failing first-line HAART were included. HIV-1 pol gene spanning 20-240 codons of RT was genotyped and mutation pattern was examined, (IAS-USA 2014 and Stanford HIV drug resistance database v7.0).
RESULTS: The median age of the participants was 35 years (IQR 29-40), CD4 T cell count of TDF failures was low at 172 cells/μL (IQR 80-252), and treatment duration was low among TDF failures (24 months vs. 61 months) (p < 0.0001). Majority of the TDF failures were on EFV based first-line (89 % vs 45 %) (p < 0.0001). Level of resistance for TDF and AZT shows, that resistance to TDF was about one-third (37 %) of TDF participants and onefourth (23 %) of AZT participants; resistance to AZT was 17 % among TDF participants and 47 % among AZT participants; resistance to both AZT and TDF was significantly high among AZT participants [21 % vs. 8 %, OR 3.057 (95 % CI 1.4-6.8), p < 0.0001].
CONCLUSIONS: Although delayed identification of treatment failure caused high levels of acquired drug resistance in our study. Thus, we must include measures to regularize virological monitoring with integrated resistance testing in LMIC (Low and Middle Income Countries) like in India; this will help to preserve the effectiveness of ARV and ensure the success of ending AIDS as public health by 2030.

Nucleoside reverse transcriptase inhibitors are the first class of drugs to be approved by the FDA for the suppression of HIV-1 and are widely used for this purpose in combination with drugs of other classes. Despite the progress in HIV-1 treatment, there is still the need to develop novel efficient antivirals. Here the efficiency of HIV-1 inhibition by a set of original 5-substituted uridine nucleosides was studied. We used the replication deficient human immunodeficiency virus (HIV-1)-based lentiviral particles and identified that among the studied compounds, 2\',3\'-isopropylidene-5-iodouridine was shown to cause anti-HIV-1 activity. Importantly, no toxic action of this compound against the cells of T-cell origin was found. We determined that this compound is significantly more efficient at suppressing HIV-1 compared to Azidothymidine (AZT) when taken at the high non-toxic concentrations. We did not find any profit when using AZT in combination with 2\',3\'-isopropylidene-5-iodouridine. 2\',3\'-Isopropylidene-5-iodouridine acts synergistically to repress HIV-1 when combined with the CDK4/6 inhibitor Palbociclib in low non-toxic concentration. No synergistic antiviral action was detected when AZT was combined with Palbociclib. We suggest 2\',3\'-isopropylidene-5-iodouridine as a novel perspective non-toxic compound that may be used for HIV-l suppression.

Anti-human immunodeficiency (HIV)-drug azidothymidine interferes with the reverse transcriptase enzyme, which results in reduced activity of HIV thereby inhibiting the growth of the virus. Owing to the side effects of high doses and short half-life of this antiviral drug azidothymidine (AZT): a fast and convenient method for its detection would be helpful for HIV patients getting treated with AZT. Referring to this, we synthesized a Biginelli based receptor R1 and evaluated its sensing properties towards AZT with different techniques (UV-Visible, circular dichroism (CD), cyclic voltammetry (CV) by preparing its organic nanoparticles (ONPs) and gold-coated ONPs (AuNP@ONP). The formation of AuNP@ONP was confirmed by UV-Visible spectroscopy, cyclic voltammetry, and HRTEM. It was observed that both the probes selectively sense AZT among various thymidine analogs but AuNP@ONP showed better response on CV, Differential pulse voltammetry (DPV) and, linear sweep voltammetry (LSV) with a detection limit of 6 nM. Proton NMR (1H NMR) reveals that the azide group present at the 3\' position is responsible for the selective response of AZT with probes. Quantitative determination by the probes in the pharmaceutical sample gives the recovery percentage above 97%. Hence, economic, affordable, ready-to-use chemosensor for AZT (in an aqueous medium) with low detection limit having satisfactory utility for HIV supplements have been developed.

Giardiasis is a diarrheal disease caused by the unicellular parasite Giardia intestinalis, for which metronidazole is the main treatment option. The parasite is dependent on exogenous deoxyribonucleosides for DNA replication and thus is also potentially vulnerable to deoxyribonucleoside analogs. Here, we characterized the G. intestinalis thymidine kinase, a divergent member of the thymidine kinase 1 family that consists of two weakly homologous parts within one polypeptide. We found that the recombinantly expressed enzyme is monomeric, with 100-fold higher catalytic efficiency for thymidine compared to its second-best substrate, deoxyuridine, and is furthermore subject to feedback inhibition by dTTP. This efficient substrate discrimination is in line with the lack of thymidylate synthase and dUTPase in the parasite, which makes deoxy-UMP a dead-end product that is potentially harmful if converted to deoxy-UTP. We also found that the antiretroviral drug azidothymidine (AZT) was an equally good substrate as thymidine and was active against WT as well as metronidazole-resistant G. intestinalis trophozoites. This drug inhibited DNA synthesis in the parasite and efficiently decreased cyst production in vitro, which suggests that it could reduce infectivity. AZT also showed a good effect in G. intestinalis-infected gerbils, reducing both the number of trophozoites in the small intestine and the number of viable cysts in the stool. Taken together, these results suggest that the absolute dependency of the parasite on thymidine kinase for its DNA synthesis can be exploited by AZT, which has promise as a future medication effective against metronidazole-refractory giardiasis.

Owing to the over usage of carbapenems, carbapenem resistance has become a vital threat worldwide, and, thus, the World Health Organization announced the carbapenem-resistant Enterobacteriaceae (CRE) as the critical priority for antibiotic development in 2017. In the current situation, combination therapy would be one solution against CRE. Azidothymidine (AZT), a thymidine analog, has demonstrated its synergistically antibacterial activities with other antibiotics. The unexpected antimicrobial activity of the immunomodulator ammonium trichloro(dioxoethylene-o,o\')tellurate (AS101) has been reported against carbapenem-resistant Klebsiella pneumoniae (CRKP). Here, we sought to investigate the synergistic activity between AS101 and AZT against 12 CRKP clinical isolates. According to the gene detection results, the blaOXA-1 (7/12, 58.3%), blaDHA (7/12, 58.3%), and blaKPC (7/12, 58.3%) genes were the most prevalent ESBL, AmpC, and carbapenemase genes, respectively. The checkerboard analysis demonstrated the remarkable synergism between AS101 and AZT, with the observable decrease in the MIC value for two agents and the fractional inhibitory concentration (FIC) index ≤0.5 in all strains. Hence, the combination of AS101 and azidothymidine could be a potential treatment option against CRKP for drug development.

In order to improve the benefit-risk ratio of pharmacokinetic (PK) research in the early development of new drugs, in silico and in vitro methods were constructed and improved. Models of intrinsic clearance rate (CLint) were constructed based on the quantitative structure-activity relationship (QSAR) of 7882 collected compounds. Moreover, a novel in vitro metabolic method, the Bio-PK dynamic metabolic system, was constructed and combined with a physiology-based pharmacokinetic model (PBPK) model to predict the metabolism and the drug-drug interaction (DDI) of azidothymidine (AZT) and fluconazole (FCZ) mediated by the phase II metabolic enzyme UDP-glycosyltransferase (UGT) in humans. Compared with the QSAR models reported previously, the goodness of fit of our CLint model was slightly improved (determination coefficient (R2) = 0.58 vs. 0.25-0.45). Meanwhile, compared with the predicted clearance of 61.96 L/h (fold error: 2.95-3.13) using CLint (8 µL/min/mg) from traditional microsomal experiment, the predicted clearance using CLint (25 μL/min/mg) from Bio-PK system was increased to 143.26 L/h (fold error: 1.27-1.36). The predicted Cmax and AUC (the area under the concentration-time curve) ratio were 1.32 and 1.84 (fold error: 1.36 and 1.05) in a DDI study with an inhibition coefficient (Ki) of 13.97 μM from the Bio-PK system. The results indicate that the Bio-PK system more truly reflects the dynamic metabolism and DDI of AZT and FCZ in the body. In summary, the novel in silico and in vitro method may provide new ideas for the optimization of drug metabolism and DDI research methods in early drug development.

UNASSIGNED: Increased sebum secretion is considered the main causative factor in the pathogenesis of acne. There is an unmet pharmacological need for a novel drug that can control sebum production with a favorable adverse effect profile.
UNASSIGNED: To investigate the effect of azidothymidine on lipid synthesis in sebocytes and to identify the underlying mechanism of the inhibitory effect of azidothymidine on insulinlike growth factor (IGF)-1-induced lipid synthesis in sebocytes.
UNASSIGNED: Immortalized human sebocytes were used for the analysis. Thin-layer chromatography (TLC) and Oil Red O staining were performed to evaluate lipid synthesis in the sebocytes. The differentiation, lipid synthesis, mitochondrial biogenesis, and mitophagy in sebocytes were investigated.
UNASSIGNED: TLC and Oil Red O staining revealed that azidothymidine reduced IGF-1 induced lipid synthesis in the immortalized human sebocytes. Azidothymidine also reduced IGF-1-induced expression of transcriptional factors and enzymes involved in sebocyte differentiation and lipid synthesis, respectively. Moreover, we found that IGF-1 upregulated the levels of peroxisome proliferator-activated receptorgamma coactivator-1α, LC-3B, p62, and Parkin, major regulators of mitochondrial biogenesis and mitophagy in immortalized human sebocytes. In contrast, azidothymidine inhibited IGF-1 induced mitochondrial biogenesis and mitophagy in the sebocytes.
UNASSIGNED: These results suggest that azidothymidine downregulates IGF-1-induced lipogenesis by dysregulating the quality of mitochondria through suppression of mitochondrial biogenesis and mitophagy in immortalized human sebocytes. Our study provides early evidence that azidothymidine may be an effective candidate for a new pharmacological agent for controlling lipogenesis in sebocytes.

Strict adherence to highly active antiretroviral therapy (HAART) is very important to improve the quality of life for HIV-positive patients to reduce new infections and determine treatment success. Azidothymidine (AZT) is an antiretroviral drug commonly used in HAART treatment. In this research, an \"add, mix, and measure\" assay was developed to detect AZT within minutes. Three different probes designed to release fluorophores when samples containing AZT are added were synthesized and characterized. The limit of detection to AZT in simulated urine samples was determined to be 4 μM in 5 min for one of the probes. This simple and rapid point-of-care test could potentially be used by clinicians and health care workers to monitor the presence of AZT in low resource settings.

Monitoring the adherence of patients taking highly active antiretroviral therapy (HAART) is a key step in treating an HIV infection, especially in resource-limited settings in the developing world. For most regimens, when patients are not at least 95% adherent to their drug schedule, there is a loss of effectiveness in treatment resulting in increases in health care costs, increases in the rate of transmission, and reduction of positive patient outcomes. Currently, subjective methods such as pill counting, electronic drug monitoring, and patient self-reporting are the only ways clinicians can track adherence and intervene in cases of noncompliance. We address this issue by developing a dipstick-based point-of-care azide-alkyne click chemistry assay with colorimetric read-out that directly tests for the presence of one common HAART drug in patient urine. An alkyne-modified dextran was synthesized and characterized by NMR and then used to colorimetrically report the presence of azidothymidine, an azide-containing HAART drug, in urine samples. The assay is specific to azide-containing molecules that are not naturally present in the urine and is sensitive to physiologically relevant urine concentrations as low as 750 uM. This point-of-care device is a strong alternative in resource-limited settings over current direct measurement techniques that are expensive and require trained users such as HPLC.

Carbapenem-resistant Enterobacteriaceae (CRE) is listed as an urgent threat by the World Health Organization because of the limited therapeutic options, rapid evolution of resistance mechanisms, and worldwide dissemination. Colistin is a common backbone agent among the \"last-resort\" antibiotics for CRE; however, its emerging resistance among CRE has taken the present dilemma to the next level. Azidothymidine (AZT), a thymidine analog used to treat human immunodeficiency virus/acquired immunodeficiency syndrome, has been known to possess antibacterial effects against Enterobacteriaceae. In this study, we investigated the combined effects of AZT and colistin in 40 clinical isolates of colistin-resistant, carbapenem-resistant K. pneumoniae (CCRKP). Eleven of the 40 isolates harbored Klebsiella pneumoniae carbapenemase. The in vitro checkerboard method and in vivo nematode killing assay both revealed synergistic activity between the two agents, with fractional inhibitory concentration indexes of ≤0.5 in every strain. Additionally, a significantly lower hazard ratio was observed for the nematodes treated with combination therapy (0.288; p < 0.0001) compared with either AZT or colistin treatment. Toxicity testing indicated potentially low toxicity of the combination therapy. Thus, the AZT-colistin combination could be a potentially favorable therapeutic option for treating CCRKP.