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International Health Feb 2021People living with HIV are at an increased risk of diabetes mellitus due to HIV infection and exposure to antiretroviral therapy (ART). Despite this, integrated diabetes...
BACKGROUND
People living with HIV are at an increased risk of diabetes mellitus due to HIV infection and exposure to antiretroviral therapy (ART). Despite this, integrated diabetes screening has not been implemented commonly in African HIV clinics. Our objective was to explore the feasibility of integrating diabetes screening into existing routine HIV viral load (VL) monitoring and to determine a group of HIV patients that benefit from a targeted screening for diabetes.
METHODS
A mixed methods study was conducted from January to July 2018 among patients on ART aged≥18 y and healthcare workers at an urban HIV clinic in Zomba Central Hospital, Malawi. Patients who were due for routine VL monitoring underwent a finger-prick for simultaneous point-of-care glucose measurement and dried blood spot sampling for a VL test. Diabetes was diagnosed according to WHO criteria. We collected demographic and medical history information using an interviewer-administered questionnaire and electronic medical records. We conducted focus group discussions among healthcare workers about their experience and perceptions regarding the integrated diabetes screening program.
RESULTS
Of patients undergoing routine VL monitoring, 1316 of 1385 (95%) had simultaneous screening for diabetes during the study period. The median age was 44 y (IQR: 38-53); 61% were female; 28% overweight or obese; and median ART duration was 83 mo (IQR: 48-115). At baseline, median CD4 count was 199 cells/mm3 (IQR: 102-277) and 50% were in WHO clinical stages I or II; 45% were previously exposed to stavudine and 88% were virologically suppressed (<1000 copies/mL). Diabetes prevalence was 31/1316 (2.4%). Diabetes diagnosis was associated with age ≥40 y (adjusted OR [aOR] 7.44; 95% CI: 1.74 to 31.80), being overweight and/or obese (aOR 2.46; 95% CI: 1.13 to 5.38) and being on a protease inhibitor-based ART regimen (aOR 5.78; 95% CI: 2.30 to 14.50). Healthcare workers appreciated integrated diabetes screening but also reported challenges including increased waiting time, additional workload and inadequate communication of results to patients.
CONCLUSIONS
Integrating diabetes screening with routine VL monitoring (every 2 y) seems feasible and was valued by healthcare workers. The additional cost of adding diabetes screening into VL clinics requires further study and could benefit from a targeted approach prioritizing patients aged ≥40 y, being overweight/obese and on protease inhibitor-based regimens.
Topics: Adult; Anti-HIV Agents; Anti-Retroviral Agents; CD4 Lymphocyte Count; Diabetes Mellitus; Female; HIV Infections; Humans; Malawi; Male; Viral Load
PubMed: 32556207
DOI: 10.1093/inthealth/ihaa030 -
PloS One 2020We have previously reported on HIV-1 infected patients who fail anti-retroviral therapy but manage to re-suppress without a regimen change despite harbouring major drug...
We have previously reported on HIV-1 infected patients who fail anti-retroviral therapy but manage to re-suppress without a regimen change despite harbouring major drug resistance mutations. Here we explore phenotypic drug resistance in such patients in order to better understand this phenomenon. Patients (n = 71) failing a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen, but who subsequently re-suppressed on the same regimen, were assessed for HIV-1 genotypic drug resistance through Sanger sequencing. A subset (n = 23) of these samples, as well as genotypically matched samples from patients who did not re-suppress (n = 19), were further assessed for phenotypic drug resistance in an in vitro single cycle assay. Half of the patients (n = 36/71, 51%) harboured genotypic drug resistance, with M184V (n = 18/36, 50%) and K103N (n = 16/36, 44%) being the most prevalent mutations. No significant difference in the median time to re-suppression (31-39 weeks) were observed for either group (p = 0.41). However, re-suppressors with mutant virus rebounded significantly earlier than those with wild-type virus (16 vs. 33 weeks; p = 0.014). Similar phenotypic drug resistance profiles were observed between patients who re-suppressed and patients who failed to re-suppress. While most remained susceptible to stavudine (d4T) and zidovudine (AZT), both groups showed a reduced susceptibility to 3TC and NNRTIs. HIV- 1 infected patients on an NNRTI-based regimen can achieve viral re-suppression on the same regimen despite harbouring viruses with genotypic and phenotypic drug resistance. However, re-suppression was less durable in those with resistance, reinforcing the importance of appropriate regimen choices, ongoing viral load monitoring and adherence counselling.
Topics: Adult; Anti-HIV Agents; Cohort Studies; Drug Resistance, Viral; Genotype; HIV Infections; HIV-1; Humans; Male; Phenotype; Reverse Transcriptase Inhibitors; Viral Load
PubMed: 32555643
DOI: 10.1371/journal.pone.0234937 -
Drug Metabolism and Disposition: the... Jul 2020Equilibrative nucleoside transporters (ENTs) transport nucleosides across the blood-testis barrier (BTB). ENTs are of interest to study the disposition of nucleoside...
Equilibrative nucleoside transporters (ENTs) transport nucleosides across the blood-testis barrier (BTB). ENTs are of interest to study the disposition of nucleoside reverse-transcriptase inhibitors (NRTIs) in the human male genital tract because of their similarity in structure to nucleosides. HeLa S3 cells express ENT1 and ENT2 and were used to compare relative interactions of these transporters with selected NRTIs. Inhibition of [H]uridine uptake by NBMPR was biphasic, with IC values of 11.3 nM for ENT1 and 9.6 μM for ENT2. Uptake measured with 100 nM NBMPR represented ENT2-mediated transport; subtracting that from total uptake represented ENT1-mediated transport. The kinetics of ENT1- and ENT2-mediated [H]uridine uptake revealed no difference in J (16.53 and 30.40 pmol cm min) and an eightfold difference in K (13.6 and 108.9 μM). The resulting fivefold difference in intrinsic clearance (J/K) for ENT1- and ENT2 transport accounted for observed inhibition of [H]uridine uptake by 100 nM NBMPR. Millimolar concentrations of the NRTIs emtricitabine, didanosine, lamivudine, stavudine, tenofovir disoproxil, and zalcitabine had no effect on ENT transport activity, whereas abacavir, entecavir, and zidovudine inhibited both transporters with IC values of ∼200 µM, 2.5 mM, and 2 mM, respectively. Using liquid chromatography-tandem mass spectrometry and [H] compounds, the data suggest that entecavir is an ENT substrate, abacavir is an ENT inhibitor, and zidovudine uptake is carrier-mediated, although not an ENT substrate. These data show that HeLa S3 cells can be used to explore complex transporter selectivity and are an adequate model for studying ENTs present at the BTB. SIGNIFICANCE STATEMENT: This study characterizes an in vitro model using S-[(4-nitrophenyl)methyl]-6-thioinosine to differentiate between equilibrative nucleoside transporter (ENT) 1- and ENT2-mediated uridine transport in HeLa cells. This provides a method to assess the influence of nucleoside reverse-transcriptase inhibitors on natively expressed transporter function. Determining substrate selectivity of the ENTs in HeLa cells can be effectively translated into the activity of these transporters in Sertoli cells that comprise the blood-testis barrier, thereby assisting targeted drug development of compounds capable of circumventing the blood-testis barrier.
Topics: Blood-Testis Barrier; Drug Evaluation, Preclinical; Equilibrative Nucleoside Transporter 1; Equilibrative-Nucleoside Transporter 2; HeLa Cells; Humans; Inhibitory Concentration 50; Nucleosides; Reverse Transcriptase Inhibitors; Zidovudine
PubMed: 32393653
DOI: 10.1124/dmd.120.090720 -
PloS One 2020We extend the method of Significant Zero Crossings of Derivatives (SiZer) to address within-subject correlations of repeatedly collected longitudinal biomarker data and...
OBJECTIVES
We extend the method of Significant Zero Crossings of Derivatives (SiZer) to address within-subject correlations of repeatedly collected longitudinal biomarker data and the computational aspects of the methodology when analyzing massive biomarker databases. SiZer is a powerful visualization tool for exploring structures in curves by mapping areas where the first derivative is increasing, decreasing or does not change (plateau) thus exploring changes and normalization of biomarkers in the presence of therapy.
METHODS
We propose a penalized spline SiZer (PS-SiZer) which can be expressed as a linear mixed model of the longitudinal biomarker process to account for irregularly collected data and within-subject correlations. Through simulations we show how sensitive PS-SiZer is in detecting existing features in longitudinal data versus existing versions of SiZer. In a real-world data analysis PS-SiZer maps are used to map areas where the first derivative of weight change after antiretroviral therapy (ART) start is significantly increasing, decreasing or does not change, thus exploring the durability of weight increase after the start of therapy. We use weight data repeatedly collected from persons living with HIV initiating ART in five regions in the International Epidemiologic Databases to Evaluate AIDS (IeDEA) worldwide collaboration and compare the durability of weight gain between ART regimens containing and not containing the drug stavudine (d4T), which has been associated with shorter durability of weight gain.
RESULTS
Through simulations we show that the PS-SiZer is more accurate in detecting relevant features in longitudinal data than existing SiZer variants such as the local linear smoother (LL) SiZer and the SiZer with smoothing splines (SS-SiZer). In the illustration we include data from 185,010 persons living with HIV who started ART with a d4T (53.1%) versus non-d4T (46.9%) containing regimen. The largest difference in durability of weight gain identified by the SiZer maps was observed in Southern Africa where weight gain in patients treated with d4T-containing regimens lasted 59.9 weeks compared to 133.8 weeks for those with non-d4T-containing regimens. In the other regions, persons receiving d4T-containing regimens experienced weight gains lasting 38-62 weeks versus 55-93 weeks in those receiving non-d4T-based regimens.
DISCUSSION
PS-SiZer, a SiZer variant, can handle irregularly collected longitudinal data and within-subject correlations and is sensitive in detecting even subtle features in biomarker curves.
Topics: Adult; Africa; Africa, Southern; Anti-HIV Agents; Biomarkers; Body Weight; Computer Simulation; Data Interpretation, Statistical; Female; HIV Infections; Humans; Longitudinal Studies; Male; Weight Gain
PubMed: 32357149
DOI: 10.1371/journal.pone.0220165 -
Toxicology Jun 2020Stavudine is an anti-AIDS drug widely used to prevent HIV transmission from pregnant mothers to the fetuses in underdeveloped countries for its low price. However, there...
Stavudine is an anti-AIDS drug widely used to prevent HIV transmission from pregnant mothers to the fetuses in underdeveloped countries for its low price. However, there is still a controversy on whether stavudine affects embryo development. In the current study, embryotoxicity of stavudine was evaluated using cultured mouse embryos with the concentrations: 5, 10, 15 μM and vehicle control. The data indicated that the effect of stavudine was dose-dependent at early neurogenesis. Stavudine exposure reduced somite numbers, yolk sac diameter, crown-rump length, and increased the rate of embryonic degeneration compared with the control. We chose the lowest but clearly toxic concentration: 5 μM to investigate the molecular mechanisms of the damage. At the molecular level, stavudine produced DNA damage, increased the levels of the phospho-CHK1 and cleaved-caspase-3, and decreased the expression level of proliferating cell nuclear antigen. These changes indicated that stavudine caused a coordinated DNA damage response, inhibited cell proliferation, and induced apoptosis in the embryos. Collectively these results suggest that stavudine exposure disturbs the embryonic development, and its use in pregnant mothers should be re-examined.
Topics: Abnormalities, Drug-Induced; Animals; Anti-HIV Agents; Apoptosis; Caspase 3; Cell Count; Cell Proliferation; Checkpoint Kinase 1; DNA Damage; Embryonic Development; Female; Mice; Mice, Inbred C57BL; Neurogenesis; Pregnancy; Proliferating Cell Nuclear Antigen; Stavudine; Yolk Sac
PubMed: 32278789
DOI: 10.1016/j.tox.2020.152443 -
Molecular Neurobiology Jun 2020cGAS is a sensor of cytosolic DNA and responds equally to exogenous and endogenous DNA. After recognition of cytosolic dsDNA or ssDNA, cGAS synthesizes the second...
cGAS is a sensor of cytosolic DNA and responds equally to exogenous and endogenous DNA. After recognition of cytosolic dsDNA or ssDNA, cGAS synthesizes the second messenger 2'3'-cGAMP, which then binds to and activates stimulator of interferon genes (STING). STING plays an essential role in responding to pathogenic DNA and self-DNA in the context of autoimmunity. In pathologic conditions, such as stroke or hypoxia-ischemia (HI), DNA can gain access into the cytoplasm of the cell and leak from the dying cells into the extracellular environment, which potentially activates cGAS/STING. Recent in vivo studies of myocardial ischemia, traumatic brain injury, and liver damage models suggest that activation of cGAS/STING is not only a side-effect of the injury, but it can also actively contribute to cell death and apoptosis. We found, for the first time, that cGAS/STING pathway becomes activated between 24 and 48 h after HI in a 10-day-old rat model. Silencing STING with siRNA resulted in decreased infarction area, reduced cortical neurodegeneration, and improved neurobehavior at 48 h, suggesting that STING can contribute to injury progression after HI. STING colocalized with lysosomal marker LAMP-1 and blocking STING reduced the expression of cathepsin B and decreased the expression of Bax and caspase 3 cleavage. We observed similar protective effects after intranasal treatment with cGAS inhibitor RU.521, which were reversed by administration of STING agonist 2'3'-cGAMP. Additionally, we showed that long interspersed element 1 (LINE-1) retrotransposon, a potential upstream activator of cGAS/STING pathway was induced at 48 h after HI, which was evidenced by increased expression of ORF1p and ORF2p proteins and increased LINE-1 DNA content in the cytosol. Blocking LINE-1 with the nucleoside analog reverse-transcriptase inhibitor (NRTI) stavudine reduced infarction area, neuronal degeneration in the cerebral cortex, and reduced the expression of Bax and cleaved caspase 3. Thus, our results identify the cGAS/STING pathway as a potential therapeutic target to inhibit delayed neuronal death after HI.
Topics: Adaptor Proteins, Signal Transducing; Animals; Cathepsin B; Cell Death; Disease Models, Animal; Gene Silencing; Hypoxia-Ischemia, Brain; Long Interspersed Nucleotide Elements; Lysosomal Membrane Proteins; Membrane Proteins; Nerve Degeneration; Nucleotides, Cyclic; Nucleotidyltransferases; RNA, Small Interfering; Rats; Signal Transduction; bcl-2-Associated X Protein
PubMed: 32253733
DOI: 10.1007/s12035-020-01904-7 -
European Review For Medical and... Feb 2020The current study was designed to investigate the effects of some nucleoside reverse transcriptase inhibitors (NRTIs) on HSV-1 infection.
OBJECTIVE
The current study was designed to investigate the effects of some nucleoside reverse transcriptase inhibitors (NRTIs) on HSV-1 infection.
MATERIALS AND METHODS
Initially, the SwissTargetPrediction server was used to predict the interactions between HSV-1 thymidine kinase and acyclovir, stavudine, zidovudine, didanosine, and entecavir. The effect of each component on Vero cell viability was assessed by the MTT assay. After treatment, the cell supernatants were collected, and HSV-1 replication was analyzed by quantitative real-time PCR.
RESULTS
The qPCR results revealed that viral titers were reduced 41, 40, 19, 44, and 31-fold in the presence of acyclovir, zidovudine, stavudine, didanosine, and entecavir, respectively.
CONCLUSIONS
Our findings indicate that NRTIs significantly reduce HSV-1 replication in cell culture.
Topics: Animals; Antiviral Agents; Chlorocebus aethiops; Dose-Response Relationship, Drug; Herpesvirus 1, Human; Reverse Transcriptase Inhibitors; Vero Cells; Virus Replication
PubMed: 32096195
DOI: 10.26355/eurrev_202002_20204 -
Expert Opinion on Therapeutic Targets Feb 2020: The purpose of the present study was to examine the chemopreventive effect of stampidine, an aryl phosphate derivative of stavudine, in side by side comparison with... (Comparative Study)
Comparative Study
: The purpose of the present study was to examine the chemopreventive effect of stampidine, an aryl phosphate derivative of stavudine, in side by side comparison with the standard anti-breast cancer drug paclitaxel in the well-established 7,12-dimethylbenz(a)anthracene (DMBA)-induced murine breast cancer model.: Groups of 20 female mice were challenged with the DMBA. DMBA-challenged mice were assigned to various chemoprevention treatments, including stampidine, paclitaxel, and stampidine plus paclitaxel according to the same treatment schedules for 25 weeks.: Stampidine resulted in substantially reduced numbers of tumors, tumor weight as well as tumor size in DMBA-treated mice. Stampidine was as effective as paclitaxel in the model and their combination exhibited greater chemopreventive activity, as measured by reduced tumor incidence and improved tumor-free survival as well as overall survival of DMBA-treated mice. The length of time for the initial tumor to appear in DMBA-challenged mice treated with stampidine was longer than that of mice treated DMBA-challenged control mice. Tumors from mice treated with stampidine or stampidine plus paclitaxel displayed unique changes of a signature protein cassette comprised BRCA1, p21, Bax, and Bcl-2.: Stampidine has potent chemopreventive activity and is as effective as the standard chemotherapy drug paclitaxel in the chemical carcinogenesis.
Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Anticarcinogenic Agents; Breast Neoplasms; Dideoxynucleotides; Disease Models, Animal; Disease-Free Survival; Female; Mice; Mice, Inbred BALB C; Paclitaxel; Stavudine; Survival Rate; Thymidine Monophosphate; Time Factors
PubMed: 32005098
DOI: 10.1080/14728222.2020.1724961 -
International Journal of Molecular... Jan 2020HIV-associated sensory neuropathy (HIV-SN) is a disabling complication of HIV disease and antiretroviral therapies (ART). Since stavudine was removed from recommended...
HIV-associated sensory neuropathy (HIV-SN) is a disabling complication of HIV disease and antiretroviral therapies (ART). Since stavudine was removed from recommended treatment schedules, the prevalence of HIV-SN has declined and associated risk factors have changed. With stavudine, rs1799964*C (TNF-1031) associated with HIV-SN in Caucasians and Indonesians but not in South Africans. Here, we investigate associations between HIV-SN and rs1799964*C and 12 other polymorphisms spanning and seven neighboring genes (the -block) in Indonesians ( = 202; 34/168 cases) and South Africans ( = 75; 29/75 cases) treated without stavudine. Haplotypes were derived using fastPHASE and haplotype networks built with PopART. There were no associations with rs1799964*C in either population. However, rs9281523*C in intron 10 of (alternatively ) independently associated with HIV-SN in Indonesians after correcting for lower CD4 T-cell counts and >500 copies of HIV RNA/mL (model = 0.0011, Pseudo = 0.09). rs4947324*T (between and ) independently associated with reduced risk of HIV-SN and African haplotype 1 (containing no minor alleles) associated with increased risk of HIV-SN after correcting for greater body weight, a history of tuberculosis and nadir CD4 T-cell counts (model: = 0.0003, Pseudo = 0.23). These results confirm -block genotypes influence susceptibility of HIV-SN. However, critical genotypes differ between ethnicities and with stavudine use.
Topics: Adult; Anti-HIV Agents; Anti-Retroviral Agents; Asian People; Black People; Female; Genetic Predisposition to Disease; Genotype; HIV Infections; Haplotypes; Humans; Indonesia; Male; Middle Aged; Peripheral Nervous System Diseases; Polymorphism, Single Nucleotide; South Africa; Stavudine; Tumor Necrosis Factor-alpha; Young Adult
PubMed: 31936167
DOI: 10.3390/ijms21020380