Science.gov

Sample records for retrovir zidovudine azt

  1. Prospective Double-Blind Study of Zidovudine (AZT) in Early Stage HIV infection

    DTIC Science & Technology

    1988-05-01

    FRONT COVER FUNDING NO. 87PP7875 S L. TITLE: Prospective Double-Blind Study of Zidovudine (AZT) in Early Stage HIV Infection PRINCIPAL INVESTIGATOR...Prospective Double-Blind Study of Zidovudine (AZT) in Early State HIV Infection 12. PERSONAL AUTHOR(S) Shannon M. Harrison 13a. TYPE OF REPORT 113b...COSATI CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUBGROUP HIV , Zidovudine, Early, Infection 06

  2. In vitro evidence of baicalein's inhibition of the metabolism of zidovudine (AZT).

    PubMed

    Wang, Yu-Cun; Yang, Hai-Yan; Kong, Ling-Ting; Yu, Feng-Xia

    2014-03-01

    Herb-drug interaction (HDI) has been regarded as a key factor limiting the clinical application of herbs and drugs. Potential baicalein-zidovudine (AZT) interaction was predicted in the present study. In vitro evaluation of baicalein's inhibition towards human liver microsomes (HLMs)-catalyzed metabolism of zidovudine (AZT) was performed. Dixon and Lineweaver-Burk plots were used to determine the inhibition kinetic type, and second plot with the slopes from Lineweaver-Burk plot versus the concentrations of baicalein was employed to calculate the inhibition parameter (Ki). In combination with the in vivo concentration of baicalein, in vitro-in vivo extrapolation (IVIVE) was carried out to predict in vivo baicalein-AZT interaction. Competitive inhibition of baicalein towards AZT metabolism was demonstrated, and the Ki value was calculated to be 101.2 µM. The value of AUCi/AUC was calculated to be 2. Potential baicalein-AZT interaction was indicated in the present study, indicating the need for monitoring when AZT is co-administrated with baicalein or baicalein-containing herbs.

  3. High Plasma Concentrations of Zidovudine (AZT) Do Not Parallel Intracellular Concentrations of AZT-Triphosphates in Infants During Prevention of Mother-to-Child HIV-1 Transmission.

    PubMed

    Kinai, Ei; Kato, Shingo; Hosokawa, Shinichi; Sadatsuki, Miyuki; Gatanaga, Hiroyuki; Kikuchi, Yoshimi; Lam, Nguyen Van; Ha, Do Quan; Kinh, Nguyen Van; Liem, Nguyen Thanh; Oka, Shinichi

    2016-07-01

    Zidovudine (AZT) is mainly used to prevent mother-to-child HIV-1 transmission (PMTCT). Despite serious concerns on AZT-associated toxicity, there is little information on pharmacokinetics of intracellular AZT metabolites in infants. We conducted a prospective study in 31 HIV-uninfected infants who received AZT for PMTCT. Blood samples were obtained from 14 infants on postdelivery days (PDD) 1, 7, 14, and 28 and from 17 infants at 0 and 4 hours after dosing on PDD-1. Plasma AZT concentrations (pAZT) and intracellular concentrations of AZT-monophosphate (icAZT-MP), diphosphate (icAZT-DP), and triphosphate (icAZT-TP) were determined. Plasma AZT and icAZT-MP concentrations were 2713 nmol/L and 79 fmol/10 cells in PDD-1, but decreased to 1437 nmol/L and 31 fmol/10 cells by PDD-28 (P = 0.02 and P = 0.07 for all PDDs, respectively), whereas those of icAZT-DP and icAZT-TP remained low throughout the sampling period (P = 0.29 and P = 0.61 for all PDDs, respectively) There were no differences in icAZT-TP between infants of the 2 mg/kg 4 times a day dose and 4 mg/kg twice daily dose (P = 0.25), whereas pAZT and icAZT-MP levels were higher in the latter (P < 0.01 and <0.01, respectively). The pAZT and icAZT-MP significantly increased from 0 to 4 hours after dosing (P < 0.001 and <0.001, respectively), whereas icAZT-DP, icAZT-TP levels were not changed (P = 0.41 and 0.33, respectively). The level of icAZT-TP did not change with age, time, or a single dose despite the wide range of pAZT concentration. A safer dosage needs to be determined because high pAZT levels do not parallel those of icAZT-TP.

  4. Role of nucleotide excision repair and p53 in zidovudine (AZT)-induced centrosomal deregulation.

    PubMed

    Momot, Dariya; Nostrand, Terri A; John, Kaarthik; Ward, Yvona; Steinberg, Seth M; Liewehr, David J; Poirier, Miriam C; Olivero, Ofelia A

    2014-12-01

    The nucleoside reverse transcriptase inhibitor zidovudine (AZT) induces genotoxic damage that includes centrosomal amplification (CA > 2 centrosomes/cell) and micronucleus (MN) formation. Here we explored these end points in mice deficient in DNA repair and tumor suppressor function to evaluate their effect on AZT-induced DNA damage. We used mesenchymal-derived fibroblasts cultured from C57BL/6J mice that were null and wild type (WT) for Xpa, and WT, haploinsufficient and null for p53 (6 different genotypes). Dose-responses for CA formation, in cells exposed to 0, 10, and 100 μM AZT for 24 hr, were observed in all genotypes except the Xpa((+/+)) p53((+/-)) cells, which had very low levels of CA, and the Xpa((-/-)) p53((-/-)) cells, which had very high levels of CA. For CA there was a significant three-way interaction between Xpa, p53, and AZT concentration, and Xpa((-/-)) cells had significantly higher levels of CA than Xpa((+/+)) cells, only for p53((+/-)) cells. In contrast, the MN and MN + chromosomes (MN + C) data showed a lack of AZT dose response. The Xpa((-/-)) cells, with p53((+/+)) or ((+/-)) genotypes, had levels of MN and MN + C higher than the corresponding Xpa((+/+)) cells. The data show that CA is a major event induced by exposure to AZT in these cells, and that there is a complicated relationship between AZT and CA formation with respect to gene dosage of Xpa and p53. The loss of both genes resulted in high levels of damage, and p53 haploinsufficicency strongly protected Xpa((+/+)) cells from AZT-induced CA damage.

  5. Enhanced transdermal delivery of AZT (Zidovudine) using iontophoresis and penetration enhancer.

    PubMed

    Oh, S Y; Jeong, S Y; Park, T G; Lee, J H

    1998-02-12

    The effect of current, its magnitude and penetration enhancers (propylene glycol/oleic acid) on the transdermal flux of AZT (Zidovudine) across hairless mouse skin was studied and the results were compared. The in vitro iontophoretic flux from AZT solution increased to about 5-40 fold that obtained by passive diffusion, depending on the magnitude of current density. When the donor side was karaya gum matrix, instead of solution, the flux enhancement effect by iontophoresis was much smaller. Incorporation of penetration enhancers into the matrix increased the passive flux 2-50 fold, depending on the amount of penetration enhancers in the matrix. These enhancers worked synergistically with iontophoresis in the transdermal transport: a much larger flux than that expected from a simple additive effect was observed. Electrical resistance data from our previous work is utilized to further discuss this synergistic effect.

  6. A Single Zidovudine (AZT) Administration Delays Hepatic Cell Proliferation by Altering Oxidative State in the Regenerating Rat Liver.

    PubMed

    Butanda-Ochoa, Armando; Hernández-Espinosa, Diego Rolando; Olguín-Martínez, Marisela; Sánchez-Sevilla, Lourdes; Rodríguez, Mario R; Chávez-Rentería, Benito; Aranda-Fraustro, Alberto; Hernández-Muñoz, Rolando

    2017-01-01

    The 3'-azido-3'-deoxythymidine or Zidovudine (AZT) was the first antiretroviral drug used in the treatment of HIV patients, which has good effectiveness but also hepatotoxic side effects that include cell cycle arrest and oxidative/nitrative mitochondrial damage. Whether such an oxidative damage may affect the proliferative-regenerative capacity of liver remains to be clearly specified at doses commonly used in the clinical practice. In this study, we described the oxidative-proliferative effect of AZT administered at a common clinical dose in rat liver submitted to 70% partial hepatectomy (PH). The results indicate that AZT significantly decreased DNA synthesis and the number of mitosis in liver subjected to PH in a synchronized way with the promotion of organelle-selective lipid peroxidation events (especially those observed in plasma membrane and cytosolic fractions) and with liver enzyme release to the bloodstream. Then at the dose used in clinical practice AZT decreased liver regeneration but stimulates oxidative events involved during the proliferation process in a way that each membrane system inside the cell preserves its integrity in order to maintain the cell proliferative process. Here, the induction of large amounts of free ammonia in the systemic circulation could become a factor capable of mediating the deleterious effects of AZT on PH-induced rat liver regeneration.

  7. A Single Zidovudine (AZT) Administration Delays Hepatic Cell Proliferation by Altering Oxidative State in the Regenerating Rat Liver

    PubMed Central

    Butanda-Ochoa, Armando; Hernández-Espinosa, Diego Rolando; Olguín-Martínez, Marisela; Sánchez-Sevilla, Lourdes; Rodríguez, Mario R.; Chávez-Rentería, Benito; Aranda-Fraustro, Alberto

    2017-01-01

    The 3′-azido-3′-deoxythymidine or Zidovudine (AZT) was the first antiretroviral drug used in the treatment of HIV patients, which has good effectiveness but also hepatotoxic side effects that include cell cycle arrest and oxidative/nitrative mitochondrial damage. Whether such an oxidative damage may affect the proliferative-regenerative capacity of liver remains to be clearly specified at doses commonly used in the clinical practice. In this study, we described the oxidative-proliferative effect of AZT administered at a common clinical dose in rat liver submitted to 70% partial hepatectomy (PH). The results indicate that AZT significantly decreased DNA synthesis and the number of mitosis in liver subjected to PH in a synchronized way with the promotion of organelle-selective lipid peroxidation events (especially those observed in plasma membrane and cytosolic fractions) and with liver enzyme release to the bloodstream. Then at the dose used in clinical practice AZT decreased liver regeneration but stimulates oxidative events involved during the proliferation process in a way that each membrane system inside the cell preserves its integrity in order to maintain the cell proliferative process. Here, the induction of large amounts of free ammonia in the systemic circulation could become a factor capable of mediating the deleterious effects of AZT on PH-induced rat liver regeneration. PMID:28479956

  8. Teratogenic and Embryocidal Effects of Zidovudine (AZT) in Sprague-Dawley Rats

    PubMed Central

    Christmas, James T.; Knoll, Kraig A.; Bawdon, Roger E.; Gilstrap III, Larry C.

    1995-01-01

    Objective: The purpose of the present investigation was to analyze the effets of zidovudine on the postimplantation embryo and fetus. Methods: Pregnant Sprague-Dawley rats were given various doses (10 mg/kg, 30 mg/kg, 150 mg/kg) of zidovudine or saline by an endotracheal tube during the period of embryogenesis (days 6–8, 9–11, 6–11 postconception). The animals were sacrificed on days 18–19 of pregnancy, and their fetuses were removed by hysterotomy. Autopsies under low (15×) and high (40×) power light microscopy were performed on all fetuses. Results: There was no statistically significant difference among the groups with respect to maternal weight gain. There were more pregnancy resorptions in the group receiving high-dose zidovudine (150 mg/kg/day) throughout embryogenesis than in the control group (P = 0.001, respectively). Four major structural anomalies were noted among the 689 fetuses examined, but zidovudine was not associated with an increased frequency of congenital anomalies in rats when it was administered in doses similar to, 3-, and 15-fold higher than the regimen recommended for adult humans. The drug, however, was embryocidal in the high-dose group (P = 0.002). Conclusions: These findings are consistent with previous studies of preimplantation mouse embryos that demonstrated an embryocidal effect on preimplantation conceptuses. In summary, post-implantation embryonic zidovudine exposure was associated with significantly increased pregnancy losses (resorptions and intrauterine deaths). PMID:18475397

  9. Synthesis, in vitro and in vivo release kinetics, and anti-HIV activity of a sustained-release prodrug (mPEG-AZT) of 3'-azido-3'-deoxythymidine (AZT, Zidovudine).

    PubMed

    Li, Wenjun; Chang, Yu; Zhan, Peng; Zhang, Na; Liu, Xinyong; Pannecouque, Christophe; De Clercq, Erik

    2010-11-08

    A poly(ethylene glycol) (PEG) conjugate of 3'-azido-3'- deoxythymidine (AZT, zidovudine) was designed and synthesized as a novel sustained-release prodrug. In the synthetic process, a succinate diester spacer was used to covalently couple AZT with methoxy poly(ethylene glycol) (mPEG; MW=2000). The conjugate was characterized by Fourier transform infrared (FTIR) and NMR spectroscopies and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS). The in vitro release was determined in hydrochloride (HCl) solution (pH 1.2) and phosphate-buffered solution (PBS; pH 6.8), which showed the release rate of AZT from the conjugate was slower than that from the free drug, suggesting its possible increased retention in gastrointestinal conditions. Pharmacokinetic properties were evaluated experimentally by oral administration in mice. Compared to free AZT, the absorption half-life (t1/2ka) and elimination half life (t1/2ß) of AZT released from the conjugate were both extended to 0.51±0.03 h (p <0.01) and 2.94±0.24 h (p <0.01), respectively. Evaluation of the in vitro anti-HIV activities showed mPEG-AZT exhibited good inhibition of HIV-1, with an EC(50) value of 0.0634 μM, but it is lower than that of free AZT. These results show that the conjugate is capable of releasing the parent drug in a sustained profile, potentially providing a feasible alternative to oral administration of AZT in a clinical setting.

  10. Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study

    SciTech Connect

    Brunetti, A.; Berg, G.; Di Chiro, G.; Cohen, R.M.; Yarchoan, R.; Pizzo, P.A.; Broder, S.; Eddy, J.; Fulham, M.J.; Finn, R.D.

    1989-05-01

    Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using (/sup 18/F)fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment.

  11. Zidovudine

    MedlinePlus

    ... Although zidovudine does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) ... sex and making other life-style changes may decrease the risk of transmitting (spreading) the HIV virus ...

  12. High Incidence of Zidovudine Induced Anaemia in HIV Infected Patients in Southern Odisha.

    PubMed

    Dash, Kaibalya Ranjan; Meher, Lalit Kumar; Hui, P K; Behera, S K; Nayak, S N

    2015-06-01

    Zidovudine (AZT), a nucleoside reverse transcriptase inhibitor was the first breakthrough in AIDS therapy in 1990.This study was conducted with an aim to determine prevalence of AZT induced anaemia in HIV infected patients initiated on AZT containing anti retroviral therapy(ART) regimen and also to find out any risk factor for causing AZT induced anaemia. Study was carried out in ART centre, M.K.C.G, MCH, Berhampur between Jan 2009 and Dec 2011. HIV infected patients registered at ART centre were treated according to National AIDS Control Organisation (NACO) guidelines. Patients (n = 1221) with Hb >8 gm/dl were prescribed AZT based ART regimen. Patients having anaemia (<8 gm/dl) were excluded from the study. Correlation of baseline characteristics (age, sex, weight, Hb level, CD4 count, World Health Organization (WHO) clinical stage) with risk of developing anaemia was also calculated. 178 (14.6 %) patients on AZT regimen developed anaemia. Patients with low CD4 count were more prone to develop severe anaemia. Age, sex, weight, WHO clinical stage had no relation with development of anaemia. Incidence of AZT induced anaemia was very high and patients having low CD4 count were more susceptible to develop anaemia.

  13. Zidovudine antagonizes the action of pyrimethamine in experimental infection with Toxoplasma gondii.

    PubMed Central

    Israelski, D M; Tom, C; Remington, J S

    1989-01-01

    The effect of zidovudine (azidothymidine; AZT) on the action of pyrimethamine against Toxoplasma gondii was investigated. Zidovudine was found to antagonize the toxoplasmacidal effect of low concentrations of pyrimethamine in vitro, and in vitro synergism of pyrimethamine and sulfadiazine against T. gondii was reversed by zidovudine. Zidovudine also antagonized the therapeutic effect of pyrimethamine in mice acutely infected with T. gondii. Images PMID:2712547

  14. Spectroscopic identification of AZT derivative obtained from biotransformation of AZT by Stenotrophomonas maltophilia

    NASA Astrophysics Data System (ADS)

    Kruszewska, Hanna; Chmielowiec, Urszula; Bednarek, Elżbieta; Witowska-Jarosz, Janina; Dobrowolski, Jan Cz.; Misicka, Aleksandra

    2003-06-01

    The 3'-azido-2',3'-dideoxy-β-ribosylthymine (AZT, Zidovudine) is a cytostatic antivirial drug worldwide used in AIDS treatment or, in combination with other antiproliferative drugs, in treatment of cancer. About 30-40% of AZT is metabolised by conjunction with glucuronic acid in liver and about 70% is eliminated untouched by urinary system. In this work a possible fate of the AZT in the environment is studied. To this end, a product of AZT biotransformation by an environmental strain, Stenotrophomonas maltophilia, (aerobic, Gram(-) rod, common in soil and water) is found and isolated by HPLC and TLC techniques and identified by NMR and mass spectroscopy. All the molecular spectroscopy methods confirm presence of the product, which is AZT molecule hydroxylated in the position 2' of the deoxyribose ring.

  15. Intracellular pharmacokinetic study of zidovudine and its phosphorylated metabolites.

    PubMed

    Mu, Lingli; Zhou, Rui; Tang, Fang; Liu, Xingling; Li, Sanwang; Xie, Feifan; Xie, Xiang; Peng, Jie; Yu, Peng

    2016-03-01

    Zidovudine (AZT), the first drug approved by the US Food and Drug Administration for the treatment of human immunodeficiency virus (HIV) infection, is metabolized in the host cells to 5'-AZT triphosphate (AZT-TP) which inhibits HIV reverse transcriptase. As the pharmacokinetics of AZT and its phosphorylated metabolites in human peripheral blood mononuclear cells (hPBMCs) is limited, the aim of this study was to determine the pharmacokinetic parameters of AZT and its phosphorylated metabolites in hPBMCs from 12 healthy Chinese male subjects after a single oral dose of 600 mg of AZT. Blood samples were collected prior to drug administration, then at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8 and 10 h after drug administration. Mononuclear cells collected by Ficoll-Hypaque density gradient centrifugation were used for determination of AZT and metabolites [AZT monophosphate (AZT-MP), AZT diphosphate (AZT-DP) and AZT-TP] and the plasma was used to evaluate the pharmacokinetics of AZT. Plasma concentration of AZT peaked within 0.583 h and intracellular concentrations of AZT, AZT-MP, AZT-DP and AZT-TP peaked within 1.083, 1.500, 1.417 and 1.583 h, respectively. AZT in plasma was eliminated rapidly with t 1/2 of 2.022 h, and AZT-MP, AZT-DP and AZT-TP were eliminated with t 1/2 of 13.428, 8.285 and 4.240 h, respectively. The plasma concentration of the phosphorylated metabolites was not quantifiable.

  16. Intracellular pharmacokinetic study of zidovudine and its phosphorylated metabolites

    PubMed Central

    Mu, Lingli; Zhou, Rui; Tang, Fang; Liu, Xingling; Li, Sanwang; Xie, Feifan; Xie, Xiang; Peng, Jie; Yu, Peng

    2015-01-01

    Zidovudine (AZT), the first drug approved by the US Food and Drug Administration for the treatment of human immunodeficiency virus (HIV) infection, is metabolized in the host cells to 5′-AZT triphosphate (AZT-TP) which inhibits HIV reverse transcriptase. As the pharmacokinetics of AZT and its phosphorylated metabolites in human peripheral blood mononuclear cells (hPBMCs) is limited, the aim of this study was to determine the pharmacokinetic parameters of AZT and its phosphorylated metabolites in hPBMCs from 12 healthy Chinese male subjects after a single oral dose of 600 mg of AZT. Blood samples were collected prior to drug administration, then at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8 and 10 h after drug administration. Mononuclear cells collected by Ficoll-Hypaque density gradient centrifugation were used for determination of AZT and metabolites [AZT monophosphate (AZT-MP), AZT diphosphate (AZT-DP) and AZT-TP] and the plasma was used to evaluate the pharmacokinetics of AZT. Plasma concentration of AZT peaked within 0.583 h and intracellular concentrations of AZT, AZT-MP, AZT-DP and AZT-TP peaked within 1.083, 1.500, 1.417 and 1.583 h, respectively. AZT in plasma was eliminated rapidly with t1/2 of 2.022 h, and AZT-MP, AZT-DP and AZT-TP were eliminated with t1/2 of 13.428, 8.285 and 4.240 h, respectively. The plasma concentration of the phosphorylated metabolites was not quantifiable. PMID:27006900

  17. Zidovudine and isoniazid induced liver toxicity and oxidative stress: Evaluation of mitigating properties of silibinin.

    PubMed

    Raghu, Ramanathan; Karthikeyan, Sivanesan

    2016-09-01

    HIV/AIDS patients are more prone for opportunistic TB infections and they are administered the combined regimen of anti-retroviral drug zidovudine (AZT) and isoniazid (INH) for therapy. However, AZT+INH treatment has been documented to induce injury and remedial measures to prevent this adversity are not clearly defined. Silibinin (SBN) is a natural hepatoprotective principle isolated from medicinal plant Silybum marianum and is currently used for therapy of various liver diseases. This study investigate the hepatotoxic potentials of AZT alone, INH alone and AZT+INH treatments and the mitigating potentials of SBN against these drugs induced toxic insults of liver in rats. Separate groups of rats (n=6 in each group) were administered AZT alone (50mg/kg b.w.), INH alone (25mg/kg, b.w.), AZT+INH (50mg/kg, b.w. and 25mg/kg, b.w.), SBN alone (100mg/kg, b.w.) and SBN+AZT+INH daily for sub-chronic period of 45days orally. The control rats received saline/propylene glycol. INH alone and AZT+INH-induced parenchymal cell injury and cholestasis of liver was evidenced by highly significant increase in the activities of marker enzymes (aspartate and alanine transaminase, alkaline phosphatase, argino succinic acid lyase), bilirubin, protein, oxidative stress parameters (lipid peroxidation, superoxide dismutase, catalase, reduced glutathione, vitamins C and E) and membrane bound ATPases were evaluated in serum/liver tissue homogenates. Histopathological studies show ballooning degradation, inflammatory lesions, lipid deposition and hydropic changes in the liver tissue. All the above biochemical and pathological changes induced by AZT+INH treatments were mitigated in rats receiving SBN simultaneously with these hepatotoxins, indicating its hepatoprotective and antioxidant potentials against AZT+INH-induced hepatotoxicity. The moderate hepatoprotective and oxidant potentials of SBN could be due to its low bioavailability and this deficiency could be prevented by supplementation of

  18. Phosphorylation of Thymidine and AZT in Heart Mitochondria

    PubMed Central

    McKee, Edward E.; Bentley, Alice T.; Hatch, Matthew; Gingerich, Joel; Susan-Resiga, Delia

    2006-01-01

    Antiretroviral nucleoside analogs used in highly active antiretroviral therapy (HAART) are associated with cardiovascular and other tissue toxicity associated with mitochondrial DNA depletion, suggesting a block in mitochondrial (mt)-DNA replication. Because the triphosphate forms of these analogs variably inhibit mt-DNA polymerase, this enzyme has been promoted as the major target of toxicity associated with HAART. We have used isolated mitochondria from rat heart to study the mitochondrial transport and phosphorylation of thymidine and AZT (azidothymidine, or zidovudine), a component used in HAART. We demonstrate that isolated mitochondria readily transport thymidine and phosphorylate it to thymidine 5′-triphosphate (TTP) within the matrix. Under identical conditions, AZT is phosphorylated only to AZT-5′-monophosphate (AZT-MP). The kinetics of thymidine and AZT suggest negative cooperativity of substrate interaction with the enzyme, consistent with work by others on mitochondrial thymidine kinase 2. Results show that TMP and AZT-MP are not transported across the inner membrane, suggesting that AZT-MP may accumulate with time in the matrix. Given the lack of AZT-5′-triphosphate (AZT-TP), it seems unlikely that the toxicity of AZT in the heart is mediated by AZT-TP inhibition of DNA polymerase γ. Rather, our work shows that AZT is a potent inhibitor of thymidine phosphorylation in heart mitochondria, having an inhibitory concentration (IC)50 of 7.0 ± 0.9 μM. Thus, the toxicity of AZT in some tissues may be mediated by disrupting the substrate supply of TTP for mt-DNA replication. PMID:15371631

  19. Structural basis of HIV-1 resistance to AZT by excision

    SciTech Connect

    Tu, Xiongying; Das, Kalyan; Han, Qianwei; Bauman, Joseph D.; Clark, Jr., Arthur D.; Hou, Xiaorong; Frenkel, Yulia V.; Gaffney, Barbara L.; Jones, Roger A.; Boyer, Paul L.; Hughes, Stephen H.; Sarafianos, Stefan G.; Arnold, Eddy

    2011-11-23

    Human immunodeficiency virus (HIV-1) develops resistance to 3'-azido-2',3'-deoxythymidine (AZT, zidovudine) by acquiring mutations in reverse transcriptase that enhance the ATP-mediated excision of AZT monophosphate from the 3' end of the primer. The excision reaction occurs at the dNTP-binding site, uses ATP as a pyrophosphate donor, unblocks the primer terminus and allows reverse transcriptase to continue viral DNA synthesis. The excision product is AZT adenosine dinucleoside tetraphosphate (AZTppppA). We determined five crystal structures: wild-type reverse transcriptase-double-stranded DNA (RT-dsDNA)-AZTppppA; AZT-resistant (AZTr; M41L D67N K70R T215Y K219Q) RT-dsDNA-AZTppppA; AZTr RT-dsDNA terminated with AZT at dNTP- and primer-binding sites; and AZTr apo reverse transcriptase. The AMP part of AZTppppA bound differently to wild-type and AZTr reverse transcriptases, whereas the AZT triphosphate part bound the two enzymes similarly. Thus, the resistance mutations create a high-affinity ATP-binding site. The structure of the site provides an opportunity to design inhibitors of AZT-monophosphate excision.

  20. Mechanisms of zidovudine-induced mitochondrial toxicity and myopathy.

    PubMed

    Scruggs, Erin R; Dirks Naylor, Amie J

    2008-01-01

    Zidovudine (3-azido-3'-deoxythymidine), also referred to as azidothymidine (AZT), has become an integral component in highly active antiretroviral therapy, and has also been used in the treatment of cancer. The clinical effectiveness of AZT is constrained due to its association with increased adverse effects, such as myopathy. There are numerous potential mechanisms that may contribute to AZT-induced myopathy. The first hypothesized mechanism to explain AZT-induced toxicity was mtDNA depletion due to inhibition of DNA polymerase gamma. Although mtDNA depletion is present in patients with myopathy, current data suggests that alternative mechanisms may play a more direct role in the myotoxicity. These mechanisms include AZT-induced oxidative stress, direct inhibition of mitochondrial bioenergetic machinery, and mitochondrial depletion of L-carnitine. Furthermore, we hypothesize that apoptosis may play a role in AZT-induced myopathy.

  1. Zidovudine Injection

    MedlinePlus

    ... zidovudine injection does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) ... sex and making other life-style changes may decrease the risk of transmitting (spreading) the HIV virus ...

  2. Effect of zidovudine on preimplantation murine embryos.

    PubMed Central

    Toltzis, P; Mourton, T; Magnuson, T

    1993-01-01

    It previously has been demonstrated that zidovudine (AZT) is lethal to early murine embryos. The effect of the drug on pre- and postimplantation embryos was examined to delineate the timing of this toxicity and to investigate its possible mechanisms. Embryos exposed in the whole mouse during preblastocyst development were unable to proceed beyond the blastocyst stage. Similarly, when two-cell embryos harvested from unexposed females were exposed to low-concentration (1 microM) AZT in vitro over 24 h, development beyond the blastocyst stage was inhibited. In contrast, drug exposure during in vitro blastocyst and postblastocyst development resulted in little or no morphologic toxicity. Further investigation revealed that preblastocyst AZT exposure resulted in the development of blastocysts with significantly lower cell numbers than control embryos. While embryonic exposure to AZT at the blastocyst and postblastocyst stages also resulted in retarded cell division, the effects were milder than those recorded after preblastocyst exposure. These data demonstrate that the critical period of AZT toxicity toward murine embryos is between ovulation and implantation and indicate that AZT directly suppresses cell division in the preimplantation embryo. PMID:8215271

  3. Human inter-individual variability in metabolism and genotoxic response to zidovudine

    SciTech Connect

    Olivero, Ofelia A. Ming, Jessica M.; Das, Shreyasi; Vazquez, Irma L.; Richardson, Diana L.; Weston, Ainsley; Poirier, Miriam C.

    2008-04-15

    A mainstay of the antiretroviral drugs used for therapy of HIV-1, zidovudine (AZT) is genotoxic and becomes incorporated into DNA. Here we explored host inter-individual variability in AZT-DNA incorporation, by AZT radioimmunoassay (RIA), using 19 different strains of normal human mammary epithelial cells (NHMECs) exposed for 24 h to 200 {mu}M AZT. Twelve of the 19 NHMEC strains showed detectable AZT-DNA incorporation levels (16 to 259 molecules of AZT/10{sup 6} nucleotides), while 7 NHMEC strains did not show detectable AZT-DNA incorporation. In order to explore the basis for this variability, we compared the 2 NHMEC strains that showed the highest levels of AZT-DNA incorporation (H1 and H2) with 2 strains showing no detectable AZT-DNA incorporation (L1 and L2). All 4 strains had similar ({>=} 80%) cell survival, low levels of accumulation of cells in S-phase, and no relevant differences in response to the direct-acting mutagen bleomycin (BLM). Finally, when levels of thymidine kinase 1 (TK1), the first enzyme in the pathway for incorporation of AZT into DNA, were determined by Western blot analysis in all 19 NHMEC strains at 24 h of AZT exposure, higher TK1 protein levels were found in the 12 strains showing AZT-DNA incorporation, compared to the 7 showing no incorporation (p = 0.0005, Mann-Whitney test). Furthermore, strains L1 and L2, which did not show AZT-DNA incorporation at 24 h, did have measurable incorporation by 48 and 72 h. These data suggest that variability in AZT-DNA incorporation may be modulated by inter-individual differences in the rate of induction of TK1 in response to AZT exposure.

  4. Susceptibility of porcine endogenous retrovirus to anti-retroviral inhibitors

    PubMed Central

    Argaw, Takele; Colon-Moran, Winston; Wilson, Carolyn

    2016-01-01

    Background Porcine endogenous retrovirus (PERV) is an endogenous retrovirus that poses a risk of iatrogenic transmission in the context of pig-to-human xenotransplantation. The lack of a means to control PERV infection in the context of pig-to-human xenotransplantation is a major concern in the field. In this study, we set out to evaluate the ability of currently licensed anti-HIV drugs, and other types of anti-retroviral compounds, to inhibit PERV infection in vitro. Methods We used target cells stably expressing one of the known PERV viral receptors, an infectious molecular clone, PERV-A 14/220, and at least one drug from each class of anti-retroviral inhibitors as well as off-label drugs shown to have anti-viral activities. The susceptibility of PERV-A 14/220 LacZ to the anti-retroviral drugs was determined from infected cells by histochemical staining. Results We extend the results of previous studies by showing that, in addition to raltegravir, dolutegravir is found to have a potent inhibitory activity against PERV replication (IC50 8.634 ±0.336 and IC50 3.06 ± 0.844 nm, respectively). The anti-HIV drug zidovudine (AZT) showed considerable anti-PERV activity with IC50 of 1.923 ±0.691 μm as well. Conclusions The study results indicate that some of the licensed antiretroviral drugs may be useful for controlling PERV infection. However, the efficacy at nanomolar concentrations put forward integrase inhibitors as a drug that has the potential to be useful in the event that xenotransplantation recipients have evidence of PERV transmission and replication. PMID:27028725

  5. Zidovudine Inhibits Thymidine Phosphorylation in the Isolated Perfused Rat Heart▿

    PubMed Central

    Susan-Resiga, Delia; Bentley, Alice T.; Lynx, Matthew D.; LaClair, Darcy D.; McKee, Edward E.

    2007-01-01

    Zidovudine (AZT; 3′-azido-3′-deoxythymidine), a thymidine analog, has been a staple of highly active antiretroviral therapy. It is phosphorylated in the host to the triphosphate and functions by inhibiting the viral reverse transcriptase. However, long-term use of AZT is linked to various tissue toxicities, including cardiomyopathy. These toxicities are associated with mitochondrial DNA depletion, which is hypothesized to be caused by AZT triphosphate inhibition of mitochondrial DNA polymerase γ. In previous work with isolated heart mitochondria, we demonstrated that AZT phosphorylation beyond the monophosphate was not detected and that AZT itself was a potent inhibitor of thymidine phosphorylation. This suggests an alternative hypothesis in which depletion of the TTP pool may limit mitochondrial DNA replication. The present work extends these studies to the whole cell by investigating the metabolism of thymidine and AZT in the intact isolated perfused rat heart. [3H]thymidine is converted to [3H]TTP in a time- and concentration-dependent manner. The level of [3H]TMP is low, suggesting that the reaction catalyzed by thymidine kinase is the rate-limiting step in phosphorylation. [3H]AZT is converted in a time- and concentration-dependent manner to AZT monophosphate, the only phosphorylated product detected after 3 h of perfusion. Both compounds display negative cooperativity, similar to the observations with cloned and purified mitochondrial thymidine kinase 2. The presence of AZT in the perfusate inhibits the phosphorylation of [3H]thymidine with a 50% inhibitory concentration of 24 ± 4 μM. These data support the hypothesis that AZT-induced mitochondrial cardiotoxicity may be caused by a limiting pool of TTP that lowers mitochondrial DNA replication. PMID:17220403

  6. Nasal chitosan microparticles target a zidovudine prodrug to brain HIV sanctuaries.

    PubMed

    Dalpiaz, Alessandro; Fogagnolo, Marco; Ferraro, Luca; Capuzzo, Antonio; Pavan, Barbara; Rassu, Giovanna; Salis, Andrea; Giunchedi, Paolo; Gavini, Elisabetta

    2015-11-01

    Zidovudine (AZT) is an antiretroviral drug that is a substrate of active efflux transporters (AETs) that extrude the drug from the central nervous system (CNS) and macrophages, which are considered to be sanctuaries of HIV. The conjugation of AZT to ursodeoxycholic acid is known to produce a prodrug (UDCA-AZT) that is able to elude the AET systems, indicating the potential ability of this prodrug to act as a carrier of AZT in the CNS and in macrophages. Here, we demonstrate that UDCA-AZT is able to permeate and remain in murine macrophages with an efficiency twenty times higher than that of AZT. Moreover, we propose the nasal administration of this prodrug in order to induce its uptake into the CNS. Chitosan chloride-based microparticles (CP) were prepared by spray-drying and were characterized with respect to size, morphology, density, water uptake and the dissolution profile of UDCA-AZT. The CP sample was then nasally administered to rats. All in vitro and in vivo measurements were also performed for a CP parent physical mixture. The CP sample was able to increase the dissolution rate of UDCA-AZT and to reduce water uptake with respect to its parent physical mixture, inducing better uptake of UDCA-AZT into the cerebrospinal fluid of rats, where the prodrug can act as an AZT carrier in macrophages.

  7. Cycle arrest and aneuploidy induced by zidovudine in murine embryonic stem cells.

    PubMed

    Campos, P B; Sartore, R C; Ramalho, B L; Costa, E S; Rehen, S K

    2012-07-01

    Zidovudine (3'-azido-3'-deoxythymidine; AZT) is a nucleoside analogue widely used for the treatment of acquired immune deficiency syndrome (AIDS). Medical guidelines recommend the use of AZT by pregnant women in order to reduce risk of HIV vertical transmission. Although it is efficacious, little is known about the side effects of AZT on embryonic development. In this sense, we used murine embryonic stem (mES) cells as a model to investigate the consequences of AZT exposure for embryogenesis. Firstly, mES colonies were incubated with AZT (50 or 100 μM) and cell cycle profile was evaluated. While 27.7 ± 5.43% of untreated mES cells were in G2/M phase, this percentage raised to 45.96 ± 4.18% after AZT exposure (100 μM). To identify whether accumulation of cells in G2/M phase could be related to chromosome missegregation with consequent cell cycle arrest, aneuploidy rate was evaluated after AZT treatment. Untreated colonies presented 39.6 ± 8.4% of cells aneuploid, while after AZT 100 μM treatment, the proportion of aneuploid cells raised to 67.8 ± 3.4% with prevalence of chromosome loss. This event was accompanied by micronuclei formation as AZT 100 μM treated mES cells presented a 2-fold increase compared to untreated ones. These data suggest that AZT exerts genotoxic effects and increases chromosome instability at early stages of embryonic development.

  8. Toxicology and Carcinogenesis Studies of Mixtures of 3'-Azido-3'-Deoxythymidine (AZT), Lamivudine (3TC), and Nevirapine (NVP) (CAS Nos. 30516-87-1, 134678-17-4, 129618-40-2) in Genetically Modified C3B6.129F1-Trp53(tm1Brd) N12 Haploinsufficient Mice (in utero and postnatal gavage studies).

    PubMed

    2013-10-01

    , both the percentage of micronucleated RETs and the percentage of micronucleated NCEs were significantly increased in the group where 3TC was coadministered with AZT compared to the group administered only AZT. Under the conditions of this gavage study, there was clear evidence of carcinogenic activity of AZT alone in male heterozygous F1 p53+/- mice based on increased incidences of hepatocellular adenoma. There was clear evidence of carcinogenic activity of AZT in combination with 3TC, and AZT in combination with 3TC and NVP in male heterozygous F1 p53+/- mice based on increased incidences of hepatocellular adenoma and hepatocellular adenoma or carcinoma (combined). The occurrence of malignant lymphoma may have been related to treatment with AZT alone and with AZT in combination with 3TC. There was no evidence of carcinogenic activity of 3TC alone in male heterozygous F1 p53+/- mice administered 150 mg/kg. There was no evidence of carcinogenic activity of NVP alone in male heterozygous F1 p53+/- mice administered 168 mg/kg. There was equivocal evidence of carcinogenic activity of NVP alone, AZT in combination with 3TC, and AZT in combination with 3TC and NVP in female heterozygous F1 p53+/- mice based on the occurrence of malignant lymphoma. There was equivocal evidence of carcinogenic activity of 3TC alone in female heterozygous F1 p53+/- mice based on the occurrence of mammary gland adenoacanthoma or adenocarcinoma (combined). There was no evidence of carcinogenic activity of AZT alone in female heterozygous F1 p53+/- mice administered 240 mg/kg. Synonyms: (3'-AZIDO-3'-DEOXYTHYMIDINE) 3'-azido-2',3'-dideoxythymidine; azidodeoxythymidine; azidothymidine; 3'-azidothymidine; AZT; BW A509U; Compound S; 3'-deoxy-3'-azidothymidine; 3'-deoxy-(8CI) (9CI); ZDV; zidovudine. Trade name: Retrovir® [Combivir® with 3TC] Synonyms: (2',3'-DIDEOXY-3'-THIACYTIDINE) 3TC; 4-amino-1-[(2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-1,2-dihydropyrimidin-2-one; L-2',3'-dideoxy-3

  9. Abacavir, Lamivudine, and Zidovudine

    MedlinePlus

    Trizivir®(as a combination product containing Abacavir, Lamivudine, and Zidovudine) ... HIV) infection. Abacavir, lamivudine and zidovudine are in a class of medications called nucleoside reverse transcriptase inhibitors ( ...

  10. Centrosomal amplification and aneuploidy induced by the antiretroviral drug AZT in hamster and human cells

    PubMed Central

    Borojerdi, Jennifer P.; Ming, Jessica; Cooch, Catherine; Ward, Yvona; Semino-Mora, Cristina; Yu, Mia; Braun, Hannan M.; Taylor, Barbara J.; Poirier, Miriam C.; Olivero, Ofelia A.

    2009-01-01

    The centrosome directs chromosomal migration by a complex process of tubulin-chromatin binding. In this contribution centrosomal abnormalities, including centrosomal amplification, were explored in Chinese Hamster Ovary (CHO) and Normal Human Mammary Epithelial (NHMEC) cells exposed to the antiretroviral drug zidovudine (3’-azido-3’-deoxythymidine, AZT). Centrosomal amplification/fragmentation was observed in both cell types and kinetochore positive micronuclei were found in AZT-exposed CHO cells in correlation with dose. Normal human mammary epithelial cell (NMHEC), strain M99005, previously identified as a strain that incorporates high levels of AZT into DNA (High incorporator, HI), showed greater centrosomal amplification when compared with a second strain, NHMEC M98040, which did not incorporate AZT into DNA (Low incorporator, LI). Additionally, an abnormal tubulin distribution was observed in AZT-exposed HI cells bearing multiple centrosomes. Immunofluorescent staining of human cells with Aurora A, a kinase involved in the maturation of the centrosome, confirmed the induction of centrosomal amplification and revealed multipolar mitotic figures. Flow cytometric studies revealed that cells bearing abnormal numbers of centrosomes and abnormal tubulin distribution had similar S-phase percentages suggesting that cells bearing unbalanced chromosomal segregation could divide. Therefore, AZT induces genomic instability and clastogenicity as well as alterations in proteins involved in centrosomal activation, all of which may contribute to the carcinogenic properties of this compound. PMID:19427513

  11. All pregnant women advised to get HIV test, consider AZT therapy.

    PubMed

    1995-03-10

    The Centers for Disease Control and Prevention (CDC) advises that all physicians counsel pregnant women to get HIV tested to reduce the risk of HIV transmission to the child. The recommendation was prompted by a report that early use of the antiviral drug zidovudine (AZT) (administered during pregnancy, labor, and childbirth) in HIV-postive pregnant women reduced the risk of HIV infection to the newborn by two-thirds. While studies are showing the value of using AZT, government officials reject mandatory testing for fear that it will force pregnant women away from prenatal care. Because the long-term effects of AZT are unknown, it is also felt that doctors should not coerce infected women into taking AZT, rather they should explain the possible benefits of the therapy as well as the unknown risk of potential side effects to her and her child. The costs of AZT are high. Some private prescription-drug insurers, however, are now covering the costs since the Food and Drug Administration (FDA) has relabeled the drug to include use in pregnancy and childbirth. The Pediatric AIDS Foundation states that an HIV test costs $25 to $30 for each of the 4 million pregnant women in the U.S., and that AZT therapy costs $1,000 for each infected woman.

  12. Quantitation of zidovudine-resistant human immunodeficiency virus type 1 in the blood of treated and untreated patients.

    PubMed Central

    Mohri, H; Singh, M K; Ching, W T; Ho, D D

    1993-01-01

    A nonselective ex vivo assay was used to directly detect and quantify zidovudine (AZT)-resistant human immunodeficiency virus type 1 (HIV-1) in the blood of treated and untreated patients. In contrast to previous reports, drug-resistant virus was detected in peripheral blood mononuclear cells of a few of the patients who had never received AZT. The AZT resistance of HIV-1 isolates from one untreated individual was confirmed by further susceptibility studies in vitro and by the finding of a characteristic mutation (Lys-->Arg at codon 70) in the reverse transcriptase. In patients who were clinically stable while on AZT, HIV-1 titers in plasma and mononuclear cells were generally low but resistant viruses already predominated. In those individuals who were deteriorating despite AZT administration, high levels of viremia were observed, and the resistance phenotype was nearly universal. These findings serve to emphasize the magnitude of the AZT-resistance problem in patients on drug treatment. PMID:7678340

  13. Ultrasensitive method to quantify intracellular zidovudine mono-, di- and triphosphate concentrations in peripheral blood mononuclear cells by liquid chromatography-tandem mass spectrometry.

    PubMed

    Kinai, Ei; Gatanaga, Hiroyuki; Kikuchi, Yoshimi; Oka, Shinichi; Kato, Shingo

    2015-06-01

    Although zidovudine (AZT) is not the preferred antiretroviral drug for adult HIV-infected patients, it is still widely used in infants for both prevention of mother-to-infant HIV-1 transmission and treatment of HIV-infected children. However, it is difficult to measure intracellular concentrations of AZT metabolites in small blood samples due to their extremely low concentrations in peripheral blood mononuclear cells and interference by endogenous nucleotide triphosphates, residual plasma phosphates and electrolytes. We developed an ultrasensitive assay using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for measurement of intracellular concentrations of zidovudine (AZT)-monophosphate (AZT-MP), -diphosphate (AZT-DP) and -triphosphate (AZT-TP). The high sensitivity was due to the improvement of peripheral blood mononuclear cells extraction for complete removal of plasma and electrolytes, alkalization of LC buffer and use of alkaline-stable high performance liquid chromatography column and tetrabutylammonium hydroxide as the ion pair. Using this method, the lower limits of quantification of AZT, AZT-MP, -DP and -TP were 6, 6, 10 and 10 fmol per sample, respectively. Accuracy ranged 89-115% and precision was lower than 15% in the quantification range of 6-6000 fmol/sample for plasma AZT and intracellular AZT-MP and 10-10 000 fmol/sample for AZT-DP and -TP. The validation parameters met the international requirements. Among nine AZT-treated HIV-infected adult patients, five had low AZT-TP levels (<10 fmol/10(6) cells). Our assay has high sensitivity and is advantageous for evaluation of AZT phosphates in children and infants based on minimum blood sampling requirement.

  14. AZT, rodent somatic and germ cell mutagenicity and reproductive toxicity tests

    SciTech Connect

    Shelby, M.D.; Russell, L.B.; Generoso, W.

    1995-11-01

    AZT (3`-axido-3`-deoxythymidine, Zidovudine) is the most widely used therapeutic agent in the treatment of Acquired Immune Deficiency Syndrome (AIDS). Use of AZT has not been limited to HIV-seropositive individuals or to those with symptoms of AIDS. It has also been used as a chemoprophylactic agent in people accidentally exposed to HIV-contaminated body fluids, and to HIV-seropositive pregnant women to prevent infection of the fetus. Because of these latter uses, it is particularly important to determine whether long-term health effects might be associated with AZT exposure. Tests have been conducted to determine the in vivo genetic toxicity of AZT in mice. Dominant-lethal and morphological-specific-locus tests were conducted in males using 2 daily initraperitoneal injections of 750 mg/kg. The dominant-lethal test was negative for all germ cell stages from differentiating spermatogonia to mature sperm. Likewise, no evidence of the induction of specific locus mutations was observed in either spermatogonial stem cells or poststem-cell stages. Further, tests for effects on male and female reproduction and in utero development indicate a lack of effects. These results, along with preliminary clinical reports that birth outcomes are normal in newborns exposed to AZT in utero, are encouraging with regard to the risks to offspring of parents exposed to AZT, either prior to or during pregnancy. However, positive results in mouse bone marrow micronucleus tests and one report on the induction of chromosomal aberrations in the lymphocytes of AIDS patients on AZT therapy indicate that further studies are needed on the potential of AZT to adversely affect the long-term health of exposed individuals.

  15. Hematological changes in women and infants exposed to an AZT-containing regimen for prevention of mother-to-child-transmission of HIV in Tanzania.

    PubMed

    Ziske, Judith; Kunz, Andrea; Sewangi, Julius; Lau, Inga; Dugange, Festo; Hauser, Andrea; Kirschner, Wolf; Harms, Gundel; Theuring, Stefanie

    2013-01-01

    Tanzanian guidelines for prevention of mother-to-child-transmission of HIV (PMTCT) recommend an antiretroviral combination regimen involving zidovudine (AZT) during pregnancy, single-dosed nevirapine at labor onset, AZT plus Lamivudine (3TC) during delivery, and AZT/3TC for 1-4 weeks postpartum. As drug toxicities are a relevant concern, we assessed hematological alterations in AZT-exposed women and their infants. A cohort of HIV-positive women, either with AZT intake (n = 82, group 1) or without AZT intake (n = 62, group 2) for PMTCT during pregnancy, was established at Kyela District Hospital, Tanzania. The cohort also included the infants of group 1 with an in-utero AZT exposure ≥4 weeks, receiving AZT for 1 week postpartum (n = 41), and infants of group 2 without in-utero AZT exposure, receiving a prolonged 4-week AZT tail (n = 58). Complete blood counts were evaluated during pregnancy, birth, weeks 4-6 and 12. For women of group 1 with antenatal AZT intake, we found a statistically significant decrease in hemoglobin level, red blood cells, white blood cells, granulocytes, as well as an increase in red cell distribution width and platelet count. At delivery, the median red blood cell count was significantly lower and the median platelet count was significantly higher in women of group 1 compared to group 2. At birth, infants from group 1 showed a lower median hemoglobin level and granulocyte count and a higher frequency of anemia and granulocytopenia. At 4-6 weeks postpartum, the mean neutrophil granulocyte count was significantly lower and neutropenia was significantly more frequent in infants of group 2. AZT exposure during pregnancy as well as after birth resulted in significant hematological alterations for women and their newborns, although these changes were mostly mild and transient in nature. Research involving larger cohorts is needed to further analyze the impact of AZT-containing regimens on maternal and infant health.

  16. Role of ABCB1, ABCG2, ABCC2 and ABCC5 transporters in placental passage of zidovudine.

    PubMed

    Neumanova, Zuzana; Cerveny, Lukas; Ceckova, Martina; Staud, Frantisek

    2016-01-01

    Zidovudine (AZT) is one of the most frequently used antiretroviral drugs in prevention of perinatal transmission of HIV. However, safety concerns on AZT use in pregnancy still persist as severe side effects are associated with AZT exposure in children. In our study we aimed to contribute to current knowledge on AZT transplacental transport and to evaluate potential involvement of the main human drug efflux ATP-binding cassette (ABC) transporters, p-glycoprotein (ABCB1), breast cancer resistance protein (ABCG2) and multidrug resistance-associated proteins 2 and 5 (ABCC2 and ABCC5) in the disposition of AZT between mother and fetus. In order to elucidate this issue we investigated the effect of selected ABC transporters on AZT transepithelial transport across MDCKII cell monolayers. In addition we used the in situ method of dually perfused rat term placenta to further study the role of ABC transporters in AZT transplacental transport. In vitro studies revealed significant effect of ABCB1 and ABCG2 on AZT transport which was subsequently confirmed also on organ level. Lamivudine, an antiretroviral agent commonly co-administered with AZT, did not affect ABC transporter-mediated AZT transfer.

  17. AZT Impairs Immunological Recovery on First-line ART: Collaborative analysis of cohort studies in Southern Africa

    PubMed Central

    WANDELER, Gilles; GSPONER, Thomas; MULENGA, Lloyd; GARONE, Daniela; WOOD, Robin; MASKEW, Mhairi; PROZESKY, Hans; HOFFMANN, Christopher; EHMER, Jochen; DICKINSON, Diana; DAVIES, Mary-Ann; EGGER, Matthias; KEISER, Olivia

    2013-01-01

    Objectives Zidovudine (AZT) is recommended for first-line antiretroviral therapy (ART) in resource limited settings. AZT may, however, lead to anemia and impaired immunological response. We compared CD4 counts over 5 years between patients starting ART with and without AZT in Southern Africa. Design Cohort study Methods Patients aged ≥16 years who started first-line ART in South Africa, Botswana, Zambia or Lesotho were included. We used linear mixed-effect models to compare CD4 cell count trajectories between patients on AZT-containing regimens and patients on other regimens, censoring follow-up at first treatment change. Impaired immunological recovery, defined as a CD4 count below 100 cells/μl at 1 year, was assessed in logistic regression. Analyses were adjusted for baseline CD4 count and haemoglobin level, age, gender, type of regimen, viral load monitoring and calendar year. Results 72,597 patients starting ART, including 19,758 (27.2%) on AZT, were analysed. Patients on AZT had higher CD4 cell counts (150 vs.128 cells/μl) and haemoglobin level (12.0 vs. 11.0 g/dl) at baseline, and were less likely to be female than those on other regimens. Adjusted differences in CD4 counts between regimens containing and not containing AZT were −16 cells/μl (95% CI −18 to −14) at 1 year and −56 cells/μl (95% CI −59 to −52) at 5 years. Impaired immunological recovery was more likely with AZT compared to other regimens (odds ratio 1.40, 95% CI 1.22–1.61). Conclusions In Southern Africa AZT is associated with inferior immunological recovery compared to other backbones. Replacing AZT with another NRTI could avoid unnecessary switches to second-line ART. PMID:23660577

  18. Long-Term Exposure to AZT, but not d4T, Increases Endothelial Cell Oxidative Stress and Mitochondrial Dysfunction

    PubMed Central

    Kline, Erik R.; Bassit, Leda; Hernandez-Santiago, Brenda I.; Detorio, Mervi A.; Liang, Bill; Kleinhenz, Dean J.; Walp, Erik R.; Dikalov, Sergey; Jones, Dean P.; Schinazi, Raymond F.

    2009-01-01

    Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (AZT) and stavudine (d4T), cause toxicities to numerous tissues, including the liver and vasculature. While much is known about hepatic NRTI toxicity, the mechanism of toxicity in endothelial cells is incompletely understood. Human aortic endothelial and HepG2 liver cells were exposed to 1 μM AZT or d4T for up to 5 weeks. Markers of oxidative stress, mitochondrial function, NRTI phosphorylation, mitochondrial DNA (mtDNA) levels, and cytotoxicity were monitored over time. In endothelial cells, AZT significantly oxidized glutathione redox potential, increased total cellular and mitochondrial-specific superoxide, decreased mitochondrial membrane potential, increased lactate release, and caused cell death from weeks 3 through 5. Toxicity occurred in the absence of di- and tri-phosphorylated AZT and mtDNA depletion. These data show that oxidative stress and mitochondrial dysfunction in endothelial cells occur with a physiologically relevant concentration of AZT, and require long-term exposure to develop. In contrast, d4T did not induce endothelial oxidative stress, mitochondrial dysfunction, or cytotoxicity despite the presence of d4T-triphosphate. Both drugs depleted mtDNA in HepG2 cells without causing cell death. Endothelial cells are more susceptible to AZT-induced toxicity than HepG2 cells, and AZT caused greater endothelial dysfunction than d4T because of its pro-oxidative effects. PMID:19067249

  19. AZT resistance of simian foamy virus reverse transcriptase is based on the excision of AZTMP in the presence of ATP

    PubMed Central

    Hartl, Maximilian J.; Kretzschmar, Benedikt; Frohn, Anne; Nowrouzi, Ali; Rethwilm, Axel; Wöhrl, Birgitta M.

    2008-01-01

    Azidothymidine (AZT, zidovudine) is one of the few nucleoside inhibitors known to inhibit foamy virus replication. We have shown previously that up to four mutations in the reverse transcriptase gene of simian foamy virus from macaque (SFVmac) are necessary to confer high resistance against AZT. To characterize the mechanism of AZT resistance we expressed two recombinant reverse transcriptases of highly AZT-resistant SFVmac in Escherichia coli harboring three (K211I, S345T, E350K) or four mutations (K211I, I224T, S345T, E350K) in the reverse transcriptase gene. Our analyses show that the polymerization activity of these mutants is impaired. In contrast to the AZT-resistant reverse transcriptase of HIV-1, the AZT resistant enzymes of SFVmac reveal differences in their kinetic properties. The SFVmac enzymes exhibit lower specific activities on poly(rA)/oligo(dT) and higher KM-values for polymerization but no change in KD-values for DNA/DNA or RNA/DNA substrates. The AZT resistance of the mutant enzymes is based on the excision of the incorporated inhibitor in the presence of ATP. The additional amino acid change of the quadruple mutant appears to be important for regaining polymerization efficiency. PMID:18096624

  20. Neurobehavioral effects of prenatal exposure to AZT: a preliminary investigation with the D1 receptor agonist SKF 38393 in mice.

    PubMed

    Venerosi, Aldina; Valanzano, Angelina; Puopolo, Maria; Calamandrei, Gemma

    2005-01-01

    Zidovudine (AZT) is the main therapeutic agent against HIV vertical transmission and is routinely administered to seropositive pregnant women and their newborns. Toxicity after chronic administration as well as citogenetic effects following developmental AZT exposure has been reported. Furthermore, recent animal data indicate alterations of several behavioral endpoints during the entire lifespan of mice and rats after developmental AZT exposure. In this study, we investigated specific central nervous system (CNS) effects of AZT administration during pregnancy on the offspring. CD-1 mouse females were administered twice daily from day 10 of pregnancy until delivery with either AZT (160 mg/kg) or saline (0.9% NaCl). On PND, 60 male offsprings received an intraperitoneal injection of the D1 receptor agonist 2,3,4,5-tetra-hydro-7,8-diol-1-phenyl-(1H)-3-benzazepine (SKF 38393) (0, 3, and 10 mg/kg), and spontaneous behavior was assessed in an automated activity chamber for 40 min. At variance from what observed in control mice that displayed excessive grooming when administered the higher dose of the D1 agonist, SKF 38393 failed to increase duration of grooming in AZT-treated mice. These data suggest that the D1 receptorial dopaminergic subsystem might be hyporesponsive in mice prenatally exposed to AZT.

  1. Clinical significance and characterization of AZT-resistant strains of HIV-1

    PubMed Central

    Wainberg, Mark A; Rooke, Ronald; Tremblay, Michel; Li, XuGuang; Parniak, Michael A; Gao, Qing; Yao, Xiao-Jian; Tsoukas, Chris; Montaner, JSG; Fanning, M; Ruedy, J

    1991-01-01

    A number of laboratories have now independently confirmed that zidovudine (AZT)-resistant strains of human immunodeficiency virus type 1 (HIV-1) may be isolated from patients undergoing prolonged therapy with this drug. In certain instances, such drug-resistant viral isolates have been obtained from patients with clinical acquired immune deficiency syndrome (aids), while in others, isolation of drug-resistant strains has been achieved in the case of HIV seropositive, asymptomatic subjects. Most of the evidence points to a series of mutations within the polymerase gene of HIV-1, which encodes viral reverse transcriptase, as being responsible for development of the drug-resistant phenotype. It further appears that over 50% of patients treated with AZT for periods longer than six months are likely to yield drug-resistant strains of HIV-1 in their circulation. Furthermore, the development of drug resistance soon after initiation of AZT therapy may potentially be correlated with the likelihood of AZT treatment failure. In several instances, cross resistance has been observed between AZT and other nucleosides being considered for potential therapy of HIV-1-associated disease. PMID:22451746

  2. Blue shifted intramolecular C-H···O improper hydrogen bonds in conformers of zidovudine

    NASA Astrophysics Data System (ADS)

    Chen, Fangfang; Selvam, Lalitha; Wang, Feng

    2010-06-01

    Blue shifted C-H stretch vibrations caused by C-H···O intramolecular improper hydrogen bonds in zidovudine (or AZT) conformers are employed to differentiate its conformers. Two sugar-sugar C-H···O (5') improper hydrogen bonds, existing in conformers of AZT with apparent drug potency, are related to their unique sugar puckering, showing C (3')- exo or - endo orientations. Aqueous solution causes a global red shift in IR spectra, but remains reduced blue shifted C-H stretch frequencies. Molecular electrostatic potentials (MEPs) of the conformers and orbitals such as 40a of AZT-B and 37a of AZT-C, which are found to be responsible for the intramolecular improper hydrogen bonds, are also given in this study.

  3. Preparation and Characterization of Chitosan Nanoparticles for Zidovudine Nasal Delivery.

    PubMed

    Barbi, Mariana Da Silva; Carvalho, Flávia Chiva; Kiill, Charlene Priscila; Barud, Hernane Da Silva; Santagneli, Sílvia Helena; Ribeiro, Sidney José Lima; Gremião, Maria Palmira Daflon

    2015-01-01

    Zidovudine (AZT) is the antiretroviral drug most frequently used for the treatment of Acquired Immunodeficiency Syndrome. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. The nasal route is an option for enhanced therapeutic efficacy and to reduce the extent of the first-pass effect. In this article, AZT loaded chitosan nanoparticles were prepared by a modified ionotropic gelation method with sodium tripolyphosphate. The increase proportion of CS (NP1 10:01 (w/w)) promoted the formation of smaller nanoparticles (260 nm), while raising the proportion of TPP (NP2 5:1 w/w) increased the nanoparticles size (330 nm). The incorporation of AZT increased the nanoparticles size for both AZT-loaded nanoparticles AZT-loaded NP1 (406 nm) and AZT-loaded NP2 (425 nm). The incorporation of AZT into NP1 did not change the electrophoretic mobility, however, in AZT-loaded NP2 there was a significant increase. The positive surface of the nanoparticles is very important for the mucoadhesive properties due interaction with the sialic groups of the mucin. Nuclear resonance magnetic data showed that the higher concentration of chitosan in the nanoparticles favored the interaction of few phosphate units (pyrophosphate) by ionic interaction Scanning electron microscopy, revealed that the nanoparticles are nearly spherical shape with porous surface. The entrapment efficiency of AZT, was 17.58% ± 1.48 and 11.02% ± 2.05 for NP1 and NP2, respectively. The measurement of the mucoadhesion force using mucin discs and nasal tissue obtained values of NP1 = 2.12 and NP2 = 4.62. In vitro permeation study showed that the nanoparticles promoted an increase in the flux of the drug through the nasal mucosa. In view of these results, chitosan nanoparticles were found to be a promising approach for the incorporation of hydrophilic drugs and these results suggest that the CS-containing nanoparticles have great potential for nasal AZT

  4. Zidovudine-poly(L-lactic acid) solid dispersions with improved intestinal permeability prepared by supercritical antisolvent process.

    PubMed

    Yoshida, Valquíria M H; Balcão, Victor M; Vila, Marta M D C; Oliveira Júnior, José M; Aranha, Norberto; Chaud, Marco V; Gremião, Maria P D

    2015-05-01

    A supercritical antisolvent (SAS) process for obtaining zidovudine-poly(L-lactic acid) (PLLA) solid dispersions (SDs) was used to attain a better intestinal permeation of this drug. A 3(2) factorial design was used, having as independent variables the ratio 3'-azido-2'3'-dideoxythymidine (AZT)-PLLA and temperature/pressure conditions, as dependent variables the process yield and particle macroscopic morphology. AZT-PLLA production batches were carried out by the SAS process, and the resulting products evaluated via scanning electron microscope, X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared analyses. From the nine possible combinations of tests performed experimentally, only one combination did not produced a solid. The L3 batch of SD, produced with 1:2 (AZT-PLLA) ratio, resulted in a 91.54% yield, with 40% AZT content. Intestinal permeability studies using the AZT-PLLA from L3 batch led to an AZT permeability of approximately 9.87%, which was higher than that of pure AZT (∼3.84%). AZT remained in crystalline form, whereas PLLA remained in semicrystalline form. AZT release is controlled by a diffusion mechanism. It has been demonstrated that it is possible to use PLLA carrier and SAS process to obtain SD, in a single step.

  5. Improved Safety, Bioavailability and Pharmacokinetics of Zidovudine through Lactoferrin Nanoparticles during Oral Administration in Rats.

    PubMed

    Kumar, Prashant; Lakshmi, Yeruva Samrajya; C, Bhaskar; Golla, Kishore; Kondapi, Anand K

    2015-01-01

    Zidovudine (AZT) is one of the most referred antiretroviral drug. In spite of its higher bioavailability (50-75%) the most important reason of its cessation are bone marrow suppression, anemia, neutropenia and various organs related toxicities. This study aims at the improvement of oral delivery of AZT through its encapsulation in lactoferrin nanoparticles (AZT-lactonano). The nanoparticles (NPs) are of 50-60 nm in size and exhibit 67% encapsulation of the AZT. They are stable in simulated gastric and intestinal fluids. Anti-HIV-1 activity of AZT remains unaltered in nanoformulation in acute infection. The bioavailability and tissue distribution of AZT is higher in blood followed by liver and kidney. AZT-lactonano causes the improvement of pharmacokinetic profile as compared to soluble AZT; a more than 4 fold increase in AUC and AUMC in male and female rats. The serum Cmax for AZT-lactonano was increased by 30%. Similarly there was nearly 2-fold increase in Tmax and t1/2. Our in vitro study confirms that, the endosomal pH is ideal for drug release from NPs and shows constant release from up to 96h. Bone marrow micronucleus assay show that nanoformulation exhibits approximately 2fold lower toxicity than soluble form. Histopathological and biochemical analysis further confirms that less or no significant organ toxicities when nanoparticles were used. AZT-lactonano has shown its higher efficacy, low organs related toxicities, improved pharmacokinetics parameter while keeping the antiviral activity intact. Thus, the nanoformulation are safe for the target specific drug delivery.

  6. Induction of ABCG2/BCRP restricts the distribution of zidovudine to the fetal brain in rats.

    PubMed

    Filia, María Fernanda; Marchini, Timoteo; Minoia, Juan Mauricio; Roma, Martín Ignacio; De Fino, Fernanda Teresa; Rubio, Modesto Carlos; Copello, Guillermo J; Evelson, Pablo A; Peroni, Roxana Noemí

    2017-09-01

    Safety concerns for fetus development of zidovudine (AZT) administration as prophylaxis of vertical transmission of HIV persist. We evaluated the participation of the ATP-binding cassette efflux transporter ABCG2 in the penetration of AZT into the fetal brain and the relevance for drug safety. Oral daily doses of AZT (60mg/kg body weight) or its vehicle were administered between post gestational days 11 (E11) and 20 (E20) to Sprague-Dawley pregnant rats. At E21, animals received an intravenous bolus of 60mg AZT/kg body weight in the presence or absence of the ABCG2 inhibitor gefitinib (20mg/kg body weight, ip) and AZT in maternal plasma and fetal brain were measured by HPLC-UV. ABCG2 protein expression in placenta and fetal brain, as well as mitochondrial function and ultrastructure in fetal brain were also analyzed. In utero chronic exposure to AZT markedly induced ABCG2 expression in placenta and fetal brain whereas did not significantly alter mitochondrial functionality in the fetal brain. The area-under-the-concentration-time-curve of AZT significantly decreased in fetal brains isolated from AZT-exposed fetuses compared to control group, but this effect was abolished by ABCG2 inhibition. Our results suggest that the absence of mitochondrial toxicity in the fetal brain after chronic in utero administration of AZT could be attributed to its low accumulation in the tissue caused, at least in part, by ABCG2 overexpression. We propose that any interference with ABCG2 activity due to genetic, pathological or iatrogenic factors would increase the amount of AZT reaching the fetal brain, which could increase the risk of toxicity of this drug on the tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Zidovudine-based lytic-inducing chemotherapy for Epstein-Barr virus-related lymphomas.

    PubMed

    Bayraktar, Ulas Darda; Diaz, Luis A; Ashlock, Brittany; Toomey, Ngoc; Cabral, Lisa; Bayraktar, Soley; Pereira, Denise; Dittmer, Dirk P; Ramos, Juan Carlos

    2014-04-01

    Treatment of Epstein-Barr virus (EBV)-related lymphomas with lytic-inducing agents is an attractive targeted approach for eliminating virus-infected tumor cells. Zidovudine (AZT) is an excellent substrate for EBV-thymidine kinase: it can induce EBV lytic gene expression and apoptosis in primary EBV+ lymphoma cell lines. We hypothesized that the combination of AZT with lytic-inducing chemotherapy agents would be effective in treating EBV+ lymphomas. We report a retrospective analysis of 19 patients with aggressive EBV+ non-Hodgkin lymphoma, including nine cases of acquired immune deficiency syndrome-associated primary central nervous system lymphoma (AIDS-PCNSL) treated with AZT-based chemotherapy. Our results demonstrate that high-dose AZT-methotrexate is efficacious in treating highly aggressive systemic EBV+ lymphomas in the upfront setting. In primary EBV+ lymphoma cell lines, the combination of AZT with hydroxyurea resulted in synergistic EBV lytic induction and cell death. Further, AZT-hydroxyurea treatment resulted in dramatic responses in patients with AIDS-PCNSL. The combination of AZT with chemotherapy, especially lytic-inducing agents, should be explored further in clinical trials for the treatment of EBV-related lymphomas.

  8. Radiosensitization effect of zidovudine on human malignant glioma cells

    SciTech Connect

    Zhou Fuxiang; Liao Zhengkai; Dai Jing; Xiong Jie; Xie CongHua; Luo Zhiguo; Liu Shiquan; Zhou Yunfeng . E-mail: yfzhouwhu@163.com

    2007-03-09

    Telomeres are shortened with each cell division and play an important role in maintaining chromosomal integrity and function. Telomerase, responsible for telomere synthesis, is activated in 90% of human tumor cells but seldom in normal somatic cells. Zidovudine (AZT) is a reverse transcriptase inhibitor. In this study, we have investigated the effects of {gamma}-radiation in combination with AZT on telomerase activity (TA), telomere length, DNA single-strand breaks (SSBs), DNA double-strand breaks (DSBs), and the changes in radiosensitivity of human malignant glioma cell line U251. The results showed that the TA was suppressed by AZT but enhanced by irradiation, resulting in a deceleration of restored rate of shortened telomere, decreased repair rate of DNA strand breaks, and increased radiosensitivity of U251 cells. Our results suggested that telomerase activity and telomere length may serve as markers for estimating the efficacy of cancer radiotherapy and reverse transcriptase inhibitors, such as AZT, may be used clinically as a new radiosensitizer in cancer radiotherapy.

  9. Lamivudine and Zidovudine

    MedlinePlus

    ... and zidovudine does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) ... sex and making other life-style changes may decrease the risk of transmitting (spreading) the HIV virus ...

  10. Acrolein enhances epigenetic modifications, FasL expression and hepatocyte toxicity induced by anti-HIV drug Zidovudine.

    PubMed

    Ghare, Smita S; Donde, Hridgandh; Chen, Wei-Yang; Barker, David F; Gobejishvilli, Leila; McClain, Craig J; Barve, Shirish S; Joshi-Barve, Swati

    2016-09-01

    Zidovudine (AZT) remains the mainstay of antiretroviral therapy against HIV in resource-poor countries; however, its use is frequently associated with hepatotoxicity. Not all HIV patients on AZT develop hepatotoxicity, and the determining factors are unclear. Alcohol consumption and cigarette smoking are known risk factors for HIV hepatotoxicity, and both are significant sources of acrolein, a highly reactive and toxic aldehyde. This study examines the potential hepatotoxic interactions between acrolein and AZT. Our data demonstrate that acrolein markedly enhanced AZT-induced transcriptionally permissive histone modifications (H3K9Ac and H3K9Me3) allowing the recruitment of transcription factor NF-kB and RNA polymerase II at the FasL gene promoter, resulting in FasL upregulation and apoptosis in hepatocytes. Notably, the acrolein scavenger, hydralazine prevented these promoter-associated epigenetic changes and inhibited FasL upregulation and apoptosis induced by the combination of AZT and acrolein, as well as AZT alone. Our data strongly suggest that acrolein enhancement of promoter histone modifications and FasL upregulation are major pathogenic mechanisms driving AZT-induced hepatotoxicity. Moreover, these data also indicate the therapeutic potential of hydralazine in mitigating AZT hepatotoxicity.

  11. Enhancement of zidovudine transfer to molt-4 cells, a human t-cell model, by dehydroepiandrosterone sulfate.

    PubMed

    Nishimura, Tomohiro; Tanaka, Jun; Tomi, Masatoshi; Seki, Yoshiaki; Kose, Noriko; Sai, Yoshimichi; Nakashima, Emi

    2011-09-01

    A possible approach to improve antiretroviral therapy with nucleoside reverse transcriptase inhibitors is to enhance inhibitor delivery to CD4-positive T cells. We previously showed that dehydroepiandrosterone sulfate (DHEAS) enhances zidovudine (AZT) transfer into syncytiotrophoblast. Here, we investigated whether DHEAS also enhances AZT transfer into a cellular model of human T lymphocytes, and whether AZT is taken up by a specific transport system. The effects of DHEAS and related compounds on the uptake of [(3) H]AZT and other nucleosides by Molt-4 cells (a model of human CD4-positive T cells) were measured. [(3) H]AZT uptake by Molt-4 cells was nitrobenzylthioinosine insensitive and pH dependent, and the uptake was significantly inhibited by 1 mM ethylisopropylamiloride. [(3) H]AZT uptake by Molt-4 cells was increased in the presence of DHEAS, whereas uptake of other nucleosides was reduced. Kinetic study revealed that the maximum uptake velocity (up to 30 min) was increased in the presence of DHEAS. The structural requirements for AZT uptake-enhancing activity were studied using structural analogues of DHEAS. Estrone-3-sulfate and 16α-hydroxy DHEAS also enhanced AZT uptake into Molt-4 cells. The use of uptake enhancers may be a good strategy to improve the efficacy of antiretroviral therapy.

  12. Brain uptake of a Zidovudine prodrug after nasal administration of solid lipid microparticles.

    PubMed

    Dalpiaz, Alessandro; Ferraro, Luca; Perrone, Daniela; Leo, Eliana; Iannuccelli, Valentina; Pavan, Barbara; Paganetto, Guglielmo; Beggiato, Sarah; Scalia, Santo

    2014-05-05

    Our previous results demonstrated that a prodrug obtained by the conjugation of the antiretroviral drug zidovudine (AZT) with ursodeoxycholic acid (UDCA) represents a potential carrier for AZT in the central nervous system, thus possibly increasing AZT efficiency as an anti-HIV drug. Based on these results and in order to enhance AZT brain targeting, the present study focuses on solid lipid microparticles (SLMs) as a carrier system for the nasal administration of UDCA-AZT prodrug. SLMs were produced by the hot emulsion technique, using tristearin and stearic acid as lipidic carriers, whose mean diameters were 16 and 7 μm, respectively. SLMs were of spherical shape, and their prodrug loading was 0.57 ± 0.03% (w/w, tristearin based) and 1.84 ± 0.02% (w/w, stearic acid based). The tristearin SLMs were able to control the prodrug release, whereas the stearic acid SLMs induced a significant increase of the dissolution rate of the free prodrug. The free prodrug was rapidly hydrolyzed in rat liver homogenates with a half-life of 2.7 ± 0.14 min (process completed within 30 min). The tristearin SLMs markedly enhanced the stability of the prodrug (75% of the prodrug still present after 30 min), whereas the stabilization effect of the stearic acid SLMs was lower (14% of the prodrug still present after 30 min). No AZT and UDCA-AZT were detected in the rat cerebrospinal fluid (CSF) after an intravenous prodrug administration (200 μg). Conversely, the nasal administration of stearic acid based SLMs induced the uptake of the prodrug in the CSF, demonstrating the existence of a direct nose-CNS pathway. In the presence of chitosan, the CSF prodrug uptake increased six times, up to 1.5 μg/mL within 150 min after nasal administration. The loaded SLMs appear therefore as a promising nasal formulation for selective zidovudine brain uptake.

  13. Design and pharmaceutical evaluation of a nano-enabled crosslinked multipolymeric scaffold for prolonged intracranial release of Zidovudine.

    PubMed

    Harilall, Sheri-lee; Choonara, Yahya E; Modi, Girish; Tomar, Lomas K; Tyagi, Charu; Kumar, Pradeep; du Toit, Lisa C; Iyuke, Sunny E; Danckwerts, Michael P; Pillay, Viness

    2013-01-01

    Nanomedicine explores and allows for the development of drug delivery devices with superior drug uptake, controlled release and fewer drug side-effects. This study explored the use of nanosystems to formulate an implantable drug delivery device capable of sustained zidovudine release over a prolonged period. Pectin and alginate nanoparticles were prepared by applying a salting out and controlled gelification approach, respectively. The nanoparticles were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS) and were further evaluated for zidovudine (AZT) entrapment efficiency. Multipolymeric scaffolds were prepared by crosslinking carboxymethyl cellulose, polyethylene oxide and epsilon caprolactone for entrapment of zidovudine-loaded alginate nanoparticles to impart enhanced controlled release of zidovudine over the time period. Swelling and textural analysis were conducted on the scaffolds. Prepared scaffolds were treated with hydrochloric acid (HCl) to reduce the swelling of matrix in the hydrated environment thereby further controlling the drug release. Drug release studies in phosphate buffered saline (pH 7.4, 37°C) were undertaken on both zidovudine-loaded nanoparticles and native scaffolds containing alginate nanoparticles. A higher AZT entrapment efficiency was observed in alginate nanoparticles. Biphasic release was observed with both nanoparticle formulations, exhibiting an initial burst release of drug within hours of exposure to PBS, followed by a constant release rate of AZT over the remaining 30 days of nanoparticle analysis. Exposure of the scaffolds to HCl served to reduce the drug release rate from the entrapped alginate nanoparticles and extended the AZT release up to 30 days. The crosslinked multipolymeric scaffold loaded with alginate nanoparticles and treated with 1% HCl showed the potential

  14. Enhancement of zidovudine uptake by dehydroepiandrosterone sulfate in rat syncytiotrophoblast cell line TR-TBT 18d-1.

    PubMed

    Nishimura, Tomohiro; Seki, Yoshiaki; Sato, Kazuko; Chishu, Takuya; Kose, Noriko; Terasaki, Tetsuya; Kang, Young-Sook; Sai, Yoshimichi; Nakashima, Emi

    2008-10-01

    AZT (3'-azido-3'-deoxythymidine; zidovudine), which is used for the prevention of mother-to-child transmission of HIV-1, is transplacentally transferred to the fetus across the blood-placenta barrier, which is composed of syncytiotrophoblasts. We recently showed that apical uptake of AZT by syncytiotrophoblasts is mediated by saturable transport system(s) in the TR-TBT 18d-1 cell line, and the cellular accumulation of AZT was increased in the presence of dehydroepiandrosterone sulfate (DHEAS). Here, we aimed to clarify the mechanism of this effect of DHEAS. Inhibitors of efflux transporters, including breast cancer resistance protein, P-glycoprotein, and multidrug resistance proteins, had little effect on the cellular accumulation of AZT in TR-TBT 18d-1. Kinetic study revealed that the rate constant for AZT uptake was greatly increased in the presence of 1 mM DHEAS. These results suggested that the effect of DHEAS was because of enhancement of the uptake process(es), rather than inhibition of efflux. When AZT uptake was analyzed according to the Michaelis-Menten equation, the estimated Michaelis constant, Km, for AZT uptake in the presence of 1 mM DHEAS was lower than that in its absence, whereas maximum uptake velocity, Vmax, and nonsaturable uptake clearance, kns, were similar in the presence and absence of DHEAS, indicating that DHEAS may change the recognition characteristics of the transporter for AZT in TR-TBT 18d-1. Thus, the increase of AZT uptake in TR-TBT 18d-1 cells in the presence of DHEAS was concluded to be because of a DHEAS-induced change in the affinity of AZT uptake system, although the transporter responsible for AZT uptake has not been identified.

  15. Zidovudine induces downregulation of mitochondrial deoxynucleoside kinases: implications for mitochondrial toxicity of antiviral nucleoside analogs.

    PubMed

    Sun, Ren; Eriksson, Staffan; Wang, Liya

    2014-11-01

    Mitochondrial thymidine kinase 2 (TK2) and deoxyguanosine kinase (dGK) catalyze the initial phosphorylation of deoxynucleosides in the synthesis of the DNA precursors required for mitochondrial DNA (mtDNA) replication and are essential for mitochondrial function. Antiviral nucleosides are known to cause toxic mitochondrial side effects. Here, we examined the effects of 3'-azido-2',3'-dideoxythymidine (AZT) (zidovudine) on mitochondrial TK2 and dGK levels and found that AZT treatment led to downregulation of mitochondrial TK2 and dGK in U2OS cells, whereas cytosolic deoxycytidine kinase (dCK) and thymidine kinase 1 (TK1) levels were not affected. The AZT effects on mitochondrial TK2 and dGK were similar to those of oxidants (e.g., hydrogen peroxide); therefore, we examined the oxidative effects of AZT. We found a modest increase in cellular reactive oxygen species (ROS) levels in the AZT-treated cells. The addition of uridine to AZT-treated cells reduced ROS levels and protein oxidation and prevented the degradation of mitochondrial TK2 and dGK. In organello studies indicated that the degradation of mitochondrial TK2 and dGK is a mitochondrial event. These results suggest that downregulation of mitochondrial TK2 and dGK may lead to decreased mitochondrial DNA precursor pools and eventually mtDNA depletion, which has significant implications for the regulation of mitochondrial nucleotide biosynthesis and for antiviral therapy using nucleoside analogs.

  16. A critical analysis of the pharmacology of AZT and its use in AIDS.

    PubMed

    Papadopulos-Eleopulos, E; Turner, V F; Papadimitriou, J M; Causer, D; Alphonso, H; Miller, T

    1999-01-01

    The triphosphorylated form of the nucleoside analogue 3'-azido-3'-deoxythymidine (Zidovudine, AZT) is claimed to interrupt the HIV replication cycle by a selective inhibition of viral reverse transcriptase, thereby preventing the formation of new proviral DNA in permissive, uninfected cells. Given that initial HIV infection of an individual instigates abundant HIV replication from inception until death, and that the life of infected T-cells is only several days, the administration of AZT should lead both in vitro and in vivo (i) to decreased formation of proviral DNA; and thus (ii) to decreased frequencies of 'HIV isolation' (detection of p24 or reverse transcription or both) in stimulated cultures/cocultures of T-cells from seropositive individuals; (iii) to decreased synthesis of HIV p24 and RNA ('antigenaemia', 'plasma viraemia', 'viral load') ultimately resulting in low or absent levels of all three parameters; and (iv) to a perfect and direct correlation between all these parameters. A critical analysis of the presently available data shows that no such evidence exists, an outcome not unexpected given the pharmacological data on AZT. HIV experts all agree that only the triphosphorylated form of AZT (AZTTP) and not the unphosphorylated form administered to patients, nor its mono- or diphosphate, is the active agent. Furthermore, the mechanism of action is the ability of AZTTP to halt the formation of HIV-DNA (chain termination). However, although this claim was posited from the outset, AZT underwent clinical trials and was introduced as a specific anti-HIV drug many years before there were any data proving that the cells of patients are able to triphosphorylate the parent compound to a level considered sufficient for its putative pharmacological action. Notwithstanding, from the evidence published since 1991 it has become apparent that no such phosphorylation takes place and thus AZT cannot possess an anti-HIV effect. However, the scientific literature does

  17. Molecular geometry, vibrational spectra, atomic charges, frontier molecular orbital and Fukui function analysis of antiviral drug zidovudine.

    PubMed

    Ramkumaar, G R; Srinivasan, S; Bhoopathy, T J; Gunasekaran, S

    2012-12-01

    The solid phase FT-IR and FT-Raman spectra of zidovudine (AZT) were recorded in the regions 4000-400 and 3500-100 cm(-1), respectively. The optimized geometry, frequency and intensity of the vibrational bands of zidovudine were obtained by the Restricted Hartree-Fock (RHF) density functional theory (DFT) with complete relaxation in the potential energy surface using 6-31G(d,p) basis set. The harmonic vibrational frequencies for zidovudine were calculated and the scaled values have been compared with experimental values of FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The harmonic vibrational wave numbers and intensities of vibrational bands of zidovudine with its cation and anion were calculated and compared with the neutral AZT. The DFT calculated HOMO and LUMO energies shows that charge transfer occurs within the molecule. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in AZT. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Molecular geometry, vibrational spectra, atomic charges, frontier molecular orbital and Fukui function analysis of antiviral drug zidovudine

    NASA Astrophysics Data System (ADS)

    Ramkumaar, G. R.; Srinivasan, S.; Bhoopathy, T. J.; Gunasekaran, S.

    2012-12-01

    The solid phase FT-IR and FT-Raman spectra of zidovudine (AZT) were recorded in the regions 4000-400 and 3500-100 cm-1, respectively. The optimized geometry, frequency and intensity of the vibrational bands of zidovudine were obtained by the Restricted Hartree-Fock (RHF) density functional theory (DFT) with complete relaxation in the potential energy surface using 6-31G(d,p) basis set. The harmonic vibrational frequencies for zidovudine were calculated and the scaled values have been compared with experimental values of FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The harmonic vibrational wave numbers and intensities of vibrational bands of zidovudine with its cation and anion were calculated and compared with the neutral AZT. The DFT calculated HOMO and LUMO energies shows that charge transfer occurs within the molecule. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in AZT.

  19. Differential gene expression in human hepatocyte cell lines exposed to the antiretroviral agent zidovudine.

    PubMed

    Fang, Jia-Long; Han, Tao; Wu, Qiangen; Beland, Frederick A; Chang, Ching-Wei; Guo, Lei; Fuscoe, James C

    2014-03-01

    Zidovudine (3'-azido-3'-deoxythymidine; AZT) is the most widely used nucleoside reverse transcriptase inhibitor for the treatment of AIDS patients and prevention of mother-to-child transmission of HIV-1. Previously, we demonstrated that AZT had significantly greater growth inhibitory effects upon the human liver carcinoma cell line HepG2 as compared to the immortalized human liver cell line THLE2. We have now used gene expression profiling to determine the molecular pathways associated with toxicity in both cell lines. HepG2 cells were incubated with 0, 2, 20, or 100 μM AZT for 2 weeks; THLE2 cells were treated with 0, 50, 500, or 2,500 μM AZT, concentrations that were equi-toxic to those used in the HepG2 cells. After the treatment, total RNA was isolated and subjected to microarray analysis. Global analysis of gene expression, with a false discovery rate ≤0.01 and a fold change ≥1.5, indicated that 6- to 70-fold more genes were differentially expressed in a significant concentration-dependent manner in HepG2 cells when compared to THLE2 cells. Comparative analysis indicated that 7 % of these genes were common to both cell lines. Among the common differentially expressed genes, 70 % changed in the same direction, most of which were associated with cell death and survival, cell cycle, cell growth and proliferation, and DNA replication, recombination, and repair. As determined by the uptake of [methyl-(3)H]AZT, the intracellular levels of total AZT were approximately twofold higher in THLE2 cells than in HepG2 cells. The expression of thymidine kinase 1 (TK1) and UDP-glucuronosyltransferase 2B7 (UGT2B7) genes that regulate the metabolic activation and deactivation of AZT, respectively, was increased in HepG2 cells but decreased in THLE2 cells after treatment with AZT. This differential response in AZT metabolism was confirmed by real-time PCR, western blotting, and/or enzymatic assays. These data indicate that molecular pathways involved with cell death and

  20. Selective protection of zidovudine-induced DNA-damage by the antioxidants WR-1065 and tempol.

    PubMed

    Olivero, Ofelia A; Ongele, Michael O; Braun, Hannan M; Marrogi, Ariadna; Divi, Kathyiani; Mitchell, James B; Poirier, Miriam C

    2014-08-01

    The cytokinesis-block micronucleus cytome (CBMN) assay, introduced by Fenech, was used to demonstrate different types of DNA damage in MOLT-3 human lymphoblastoid cells exposed to 10 μM zidovudine (AZT). In addition, we explored the cytoprotective potential of two antioxidants, WR-1065 and Tempol, to decrease AZT-induced genotoxicity. Binucleated cells, arrested by Cytochalasin B (Cyt B), were evaluated for micronuclei (MN), caused by DNA damage or chromosomal loss, and chromatin nucleoplasmic bridges (NPBs), caused by telomere attrition. Additionally, nuclear buds (NBUDs), caused by amplified DNA, and apoptotic and necrotic (A/N) cells were scored. We hypothesized that AZT exposure would increase the frequency of genotoxic end points, and that the antioxidants Tempol and WR-1065 would protect against AZT-induced genotoxicity. MOLT-3 cells were exposed to 0 or 10 µM AZT for a total of 76 hr. After the first 24 hr, 0 or 5 µM WR-1065 and/or 0 or 200 µM Tempol were added for the remainder of the experiment. For the last 28 hr (of 76 hr), Cyt B was added to arrest replication after one cell division, leaving a predominance of binucleated cells. The nuclear division index (NDI) was similar for all treatment groups, indicating that the exposures did not alter cell viability. MOLT-3 cells exposed to AZT alone had significant (P < 0.05) increases in MN and NBs, compared to unexposed cells. Both Tempol and WR-1065 protected against AZT-induced MN formation (P < 0.003 for both), and WR-1065, but not Tempol, reduced the levels of A/N (P = 0.041). In cells exposed to AZT/Tempol there were significantly reduced levels of NBUDs, compared to cells exposed to AZT alone (P = 0.015). Cells exposed to AZT/WR-1065 showed reduced levels of NPBs, compared to cells exposed to AZT alone (P = 0.037). Thus WR-1065 and Tempol protected MOLT-3 cells against specific types of AZT-induced DNA damage.

  1. Evaluation of Hepatic Mitochondria and Hematological Parameters in Zidovudine-Treated B6C3F1 Mice

    PubMed Central

    Desai, Varsha G.; Lee, Taewon; Moland, Carrie L.; Branham, William S.; Mittelstaedt, Roberta A.; Lewis, Sherry M.; Leakey, Julian E. A.; Fuscoe, James C.

    2012-01-01

    The effects of 12-week exposure to zidovudine (AZT) at 400, 500, and 600 mg/kg/d were examined on expression of 542 mitochondria-related genes and mitochondrial DNA (mtDNA) copy number in the liver of male and female B6C3F1 mice to understand mitochondrial role in sex-related differences in development of lactic acidosis. Plasma lactate levels and hematologic parameters were also examined. Results indicated increased red blood cell (RBC) count in vehicle-treated controls, whereas a dose-related decline in the RBC count was noted in AZT-treated mice compared to the basal levels before treatments began. These decreases were associated with significant dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin levels. This effect was greater in AZT-treated females compared to males. In both sexes, 12-week AZT or vehicle exposure significantly reduced plasma lactate levels compared to the basal levels. Results also showed modest, but significant, changes in the expression of genes associated with apoptosis and lipid metabolism at 600 mg/kg/d AZT. Neither drug nor sex influenced hepatic mtDNA copy number. Altogether, 12-week AZT exposure as high as 600 mg/kg/d did not impair hepatic mitochondria or induce lactic acidosis in B6C3F1 mice. However, AZT-mediated hematologic toxicity appeared to be greater in females compared to males. PMID:22545210

  2. Evaluation of Hepatic Mitochondria and Hematological Parameters in Zidovudine-Treated B6C3F(1) Mice.

    PubMed

    Desai, Varsha G; Lee, Taewon; Moland, Carrie L; Branham, William S; Mittelstaedt, Roberta A; Lewis, Sherry M; Leakey, Julian E A; Fuscoe, James C

    2012-01-01

    The effects of 12-week exposure to zidovudine (AZT) at 400, 500, and 600 mg/kg/d were examined on expression of 542 mitochondria-related genes and mitochondrial DNA (mtDNA) copy number in the liver of male and female B6C3F(1) mice to understand mitochondrial role in sex-related differences in development of lactic acidosis. Plasma lactate levels and hematologic parameters were also examined. Results indicated increased red blood cell (RBC) count in vehicle-treated controls, whereas a dose-related decline in the RBC count was noted in AZT-treated mice compared to the basal levels before treatments began. These decreases were associated with significant dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin levels. This effect was greater in AZT-treated females compared to males. In both sexes, 12-week AZT or vehicle exposure significantly reduced plasma lactate levels compared to the basal levels. Results also showed modest, but significant, changes in the expression of genes associated with apoptosis and lipid metabolism at 600 mg/kg/d AZT. Neither drug nor sex influenced hepatic mtDNA copy number. Altogether, 12-week AZT exposure as high as 600 mg/kg/d did not impair hepatic mitochondria or induce lactic acidosis in B6C3F(1) mice. However, AZT-mediated hematologic toxicity appeared to be greater in females compared to males.

  3. AZT resistance alters enzymatic properties and creates an ATP-binding site in SFVmac reverse transcriptase.

    PubMed

    Schneider, Anna; Schweimer, Kristian; Rösch, Paul; Wöhrl, Birgitta M

    2015-02-22

    The replication of simian foamy virus from macaques can be inhibited by the nucleoside reverse transcriptase inhibitor azidothymidine (AZT, zidovudine). Four substitutions in the protease-reverse transcriptase (PR-RT) protein (K211I, I224T, S345T, E350K) are necessary to obtain highly AZT resistant and fully replication competent virus. AZT resistance is based on the excision of the incorporated AZTMP in the presence of ATP. I224T is a polymorphism which is not essential for AZT resistance per se, but is important for regaining efficient replication of the resistant virus. We constructed PR-RT enzymes harboring one to four amino acid substitutions to analyze them biochemically and to determine their ability to remove the incorporated AZTMP. S345T is the only single substitution variant exhibiting significant AZTMP excision activity. Although K211I alone showed no AZTMP excision activity, excision efficiency doubled when K211I was present in combination with S345T and E350K. K211I also decreased nucleotide binding affinity and increased fidelity. NMR titration experiments revealed that a truncated version of the highly AZT resistant mt4 variant, comprising only the fingers-palm subdomains was able to bind ATP with a KD-value of ca. 7.6 mM, whereas no ATP binding could be detected in the corresponding wild type protein. We could show by NMR spectroscopy that S345T is responsible for ATP binding, probably by making a tryptophan residue accessible. Although AZT resistance in SFVmac is based on excision of the incorporated AZTMP like in HIV-1, the functions of the resistance substitutions in SFVmac PR-RT appear to be different. No mutation resulting in an aromatic residue like F/Y215 in HIV, which is responsible for π-π-stacking interactions with ATP, is present in SFVmac. Instead, S345T is responsible for creating an ATP binding site, probably by making an already existing tryptophan more accessible, which in turn can interact with ATP. This is in contrast to HIV-1

  4. Parameterization of AZT-A widely used nucleoside inhibitor of HIV-1 reverse transcriptase

    NASA Astrophysics Data System (ADS)

    Carvalho, Alexandra T. P.; Fernandes, Pedro A.; Ramos, Maria J.

    Seven nucleoside reverse transcriptase (RT) inhibitors are currently used in the clinical treatment of acquired immunodeficiency syndrome (AIDS). These substrate analogues block DNA synthesis by the viral enzyme RT. However, the emergence of resistant variants of RT allied to their long-term toxicity requires the design of new and better RT inhibitors, with long-term in vivo efficacy. In this work we used density functional theory (DFT) calculations to develop a set of molecular mechanics (MM) parameters committed to the AMBER force field for one of the most used in the clinic nucleoside reverse transcriptase inhibitors (NRTIs): zidovudine (AZT). These parameters were tested by comparing the optimized geometries of AZT at both the DFT and MM levels of theory. The ability of the new parameters to reproduce the torsional energy of the azide group was also verified by scanning the surface in MM with the new parameters and comparing the results with the same potential energy surface (PES) at the DFT level. Finally, the parameters were validated through classical MD simulations of AZT in aqueous environment.

  5. [Pharmacokinetic Effect of Aikeqing Granule by Different Medication Ways on Zidovudine in HAART of Rats].

    PubMed

    Lu, Zhen-zhen; Su, Qi-jian; Ma, Jia-bao; Tang, Dan-hui; Song, Ce; Fu, Lin-chun

    2015-12-01

    To study pharmacokinetic effect of Aikeqing Granule (AG) by different medication ways on zidovudine (AZT) in highly active antiretroviral therapy ( HAART) of rats. Totally 36 rats were administered with corresponding medications by gastrogavage, group I [HAART: AZT 31.5 mg/kg +3TC 31.5 mg/kg + Efavirenz (EFV) 63.0 mg/kg], group II (HAART+AG525 mg/kg), group III (HAART and AG 525 mg/kg after a 2-h interval). Drug concentrations of AZT were determined by high performance liquid chromatography-mass spectroscopy (HPLC-MS) before HAART, and at 0.5, 1, 2, 3, 4, 6, 8, 10, 12 h after HAART, respectively. Pharmacokinetic parameters [such as t1/2, Tmax, Cmax, AUCo-t, plasma clearance rate (CL)] were calculated by DAS2.0 Software. The-equation of linear regression of AZT was good, with the precision, coefficient of recovery, and stability definitely confirmed. AUC in group II and III was larger than that of group I. There was no statistical difference in t1/2, Tmax, Cmax, AUC0-12 h, or AUC0-∞ among groups (P > 0.05). AG combined HAART could enhance the Cmax of AZT.

  6. Simultaneous determination of zidovudine and lamivudine in human serum using HPLC with tandem mass spectrometry.

    PubMed

    Kenney, K B; Wring, S A; Carr, R M; Wells, G N; Dunn, J A

    2000-07-01

    A method employing high performance liquid chromatography (HPLC) with tandem mass spectrometry (MS) has been developed and validated for the simultaneous determination of clinically relevant levels of zidovudine (AZT) and lamivudine (3TC) in human serum. The method incorporates a fully automated ultrafiltration sample preparation step that replaces the solid-phase extraction step typically used for HPLC with UV detection. The calibration range of the dual-analyte LC-MS/MS method is 2.5-2,500 and 2.5-5,000 ng ml-1 for AZT and 3TC, respectively, using 0.25 ml of human serum. The lower limit of quantification was 2.5 ng ml-1 for each analyte, with a chromatographic run time of approximately 6 min. Overall accuracy, expressed as bias, and inter- and intra-assay precision are < +/- 7 and < 10% for AZT, and < +/- 5 and < 12.1% for 3TC over the full concentration ranges. A cross-validation study demonstrated that the LC-MS/MS method afforded equivalent results to established methods consisting of a radioimmuno-assay for AZT and an HPLC-UV method for 3TC. Moreover, the LC-MS/MS was more sensitive, allowed markedly higher-throughput, and required smaller sample volumes (for 3TC only). The validated method has been used to support post-marketing clinical studies for Combivir a combination tablet containing AZT and 3TC.

  7. Zidovudine-based lytic-inducing chemotherapy for Epstein–Barr virus-related lymphomas

    PubMed Central

    Bayraktar, Ulas Darda; Diaz, Luis A.; Ashlock, Brittany; Toomey, Ngoc; Cabral, Lisa; Bayraktar, Soley; Pereira, Denise; Dittmer, Dirk P.; Ramos, Juan Carlos

    2014-01-01

    Treatment of Epstein–Barr virus (EBV)-related lymphomas with lytic-inducing agents is an attractive targeted approach for eliminating virus-infected tumor cells. Zidovudine (AZT) is an excellent substrate for EBV-thymidine kinase: it can induce EBV lytic gene expression and apoptosis in primary EBV+ lymphoma cell lines. We hypothesized that the combination of AZT with lytic-inducing chemotherapy agents would be effective in treating EBV+ lymphomas. We report a retrospective analysis of 19 patients with aggressive EBV+ non-Hodgkin lymphoma, including nine cases of acquired immune deficiency syndrome-associated primary central nervous system lymphoma (AIDSPCNSL) treated with AZT-based chemotherapy. Our results demonstrate that high-dose AZT–methotrexate is efficacious in treating highly aggressive systemic EBV+ lymphomas in the upfront setting. In primary EBV+ lymphoma cell lines, the combination of AZT with hydroxyurea resulted in synergistic EBV lytic induction and cell death. Further, AZT–hydroxyurea treatment resulted in dramatic responses in patients with AIDSPCNSL. The combination of AZT with chemotherapy, especially lytic-inducing agents, should be explored further in clinical trials for the treatment of EBV-related lymphomas. PMID:23837493

  8. XPC is essential for nucleotide excision repair of zidovudine-induced DNA damage in human hepatoma cells

    SciTech Connect

    Wu Qiangen; Beland, Frederick A.; Chang, Ching-Wei; Fang Jialong

    2011-03-01

    Zidovudine (3'-azido-3'-dexoythymidine, AZT), a nucleoside reverse transcriptase inhibitor, can be incorporated into DNA and cause DNA damage. The mechanisms underlying the repair of AZT-induced DNA damage are unknown. To investigate the pathways involved in the recognition and repair of AZT-induced DNA damage, human hepatoma HepG2 cells were incubated with AZT for 2 weeks and the expression of DNA damage signaling pathways was determined using a pathway-based real-time PCR array. Compared to control cultures, damaged DNA binding and nucleotide excision repair (NER) pathways showed significantly increased gene expression. Further analysis indicated that AZT treatment increased the expression of genes associated with NER, including XPC, XPA, RPA1, GTF2H1, and ERCC1. Western blot analysis demonstrated that the protein levels of XPC and GTF2H1 were also significantly up-regulated. To explore further the function of XPC in the repair of AZT-induced DNA damage, XPC expression was stably knocked down by 71% using short hairpin RNA interference. In the XPC knocked-down cells, 100 {mu}M AZT treatment significantly increased [{sup 3}H]AZT incorporation into DNA, decreased the total number of viable cells, increased the release of lactate dehydrogenase, induced apoptosis, and caused a more extensive G2/M cell cycle arrest when compared to non-transfected HepG2 cells or HepG2 cells transfected with a scrambled short hairpin RNA sequence. Overall, these data indicate that XPC plays an essential role in the NER repair of AZT-induced DNA damage.

  9. Is zidovudine first-line therapy virologically comparable to tenofovir in resource-limited settings?

    PubMed

    Labhardt, Niklaus D; Bader, Joëlle; Lejone, Thabo Ismael; Ringera, Isaac; Puga, Daniel; Glass, Tracy R; Klimkait, Thomas

    2015-07-01

    To compare virologic success between adult patients on tenofovir (TDF) and zidovudine (AZT)-containing first-line antiretroviral (ART) regimens in 10 rural clinics in Lesotho, Southern Africa. Multicentre cross-sectional study, patients ≥16 years, on first-line ART ≥6 months, receiving AZT/lamivudine (3TC) or TDF/3TC combined with efavirenz (EFV) or nevirapine (NVP). Patient characteristics and clinical/therapeutic history were collected on the day of blood draw for viral load (VL). Analysis was stratified for non-nucleoside reverse transcriptase inhibitor (EFV or NVP). A logistic regression model weighted for patients' baseline characteristics was used to assess the likelihood of virologic success (<80 copies/ml) in patients with TDF- as compared to AZT-backbones. In total 1539 patients were included in the analysis. Most were clinically and immunologically stable (clinical failure: 2.7% (AZT) and 2.8% (TDF); immunological failure: 4.6% (AZT) and 4.8% (TDF)). In EFV-based regimens (n = 1162), TDF was significantly associated with higher rates of virologic suppression than AZT (93.8% vs. 88.1%; weighted odds ratio: 2.15 (95% CI: 1.29-3.58; P = 0.003)). In NVP-based regimens, a similar trend was observed, but not significant (89.4% vs. 86.7%; 1.99 (0.83-4.75, P = 0.121)). These findings support the WHO recommendation to use TDF/3TC/EFV as first-line regimen. They do, however, not support the recommendation that patients who are clinically stable on AZT should continue on this first-line regimen. © 2015 John Wiley & Sons Ltd.

  10. Biological comparison of wild-type and zidovudine-resistant isolates of human immunodeficiency virus type 1 from the same subjects: susceptibility and resistance to other drugs.

    PubMed Central

    Rooke, R; Parniak, M A; Tremblay, M; Soudeyns, H; Li, X G; Gao, Q; Yao, X J; Wainberg, M A

    1991-01-01

    We used a viral endpoint dilution assay to show changes in the proportion of zidovudine (azidothymidine; AZT)-resistant viruses within a heterogeneous mixture of human immunodeficiency virus type 1 (HIV-1) quasispecies isolated from patients on long-term AZT therapy. Several HIV-1 isolates, which could replicate in 10 microM AZT, were susceptible to both 2',3'-dideoxycytidine and a novel cytosine analog BCH-189, in which a sulfur atom replaces the 3' carbon of the pentose ring. In certain instances, cross-resistance was seen with 3'-didehydro-2',3'-dideoxythymidine. Although most strains of AZT-resistant HIV-1 displayed reduced susceptibility to 3'-azido-2',3'-dideoxyuridine, two strains were identified for which this was not the case. PMID:1649576

  11. Canadian multicenter azidothymidine trial: AZT pharmacokinetics.

    PubMed

    Child, S; Montaner, J; Tsoukas, C; Fanning, M; Le, T; Wall, R A; Ruedy, J

    1991-01-01

    The study objective was to describe the pharmacokinetics of azidothymidine (AZT) in a large population of early, asymptomatic human immunodeficiency virus (HIV)-infected individuals. The study design was a multicenter, prospective, descriptive single-dose pharmacokinetic study. Each of 66 fasting, male, HIV-infected homosexuals older than 18 years of age and in CDC classifications II, III, and IVC2 received a single 400-mg oral dose of AZT with subsequent pharmacokinetic measurements performed during an 8-h period for AZT and its major metabolite, glucuronylazidothymidine (GAZT). Results were obtained in 65 patients (36 smokers, 29 nonsmokers), of whom 3 were noted to have hepatic dysfunction. In those with normal hepatic function, the following parameters were described: AZT, area under the curve (AUC) +/- SD, 9.9 +/- 5.7 microM.h, maximum concentration (Cmax) +/- SD, 7.3 +/- 4.7 microM; time to maximum concentration (Tmax) +/- SD, 0.93 +/- 0.42 h, and half-life (t1/2) +/- SD, 1.0 +/- 0.8 h. Corresponding values for GAZT were: AUC +/- SD 35.7 +/- 10.3 microM.h, Cmax +/- SD 21.3 +/- 7.3 microM, Tmax +/- SD 1.2 +/- 0.50 h, t1/2 +/- SD 0.98 +/- 0.62 h, No significant differences were found in comparisons of study site, CDC classification of disease, smokers versus nonsmokers, and in patients with hepatic dysfunction, although a higher AUC and earlier Cmax for AZT was noted in the latter group. It is concluded that AZT pharmacokinetics are similar in patients with early asymptomatic HIV disease when compared with previous reports in patients with later disease.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Effect of HIV nucleoside reverse transcriptase inhibitor, Zidovudine, on the growth and differentiation of primary gingival epithelium

    PubMed Central

    Mitchell, Danielle; Israr, Mohd; Alam, Samina; Kishel, Joseph; Dinello, Donald; Meyers, Craig

    2011-01-01

    Oral complications associated with immunodeficiency virus (HIV) with antiretroviral drugs are becoming a mounting concern in HIV patients. Protease inhibitors have been shown to change the proliferation and differentiation state of oral tissues but the effect of nucleoside inhibitors is currently unknown. This study examines the effect of Zidovudine, also known as AZT, on the growth and differentiation of gingival epithelium. Methods Gingival keratinocytes Organotypic (raft) cultures were established. Raft cultures were treated with a range of Zidovudine concentrations. Hematoxylin and eosin staining was performed to examine the effect of Zidovudine on gingival epithelium growth and stratification. Raft cultures were immunohistochemically analyzed to determine the effect of this drug on the expression of key differentiation and proliferation markers including cytokeratins and PCNA. Results Zidovudine dramatically changed the proliferation and differentiation state of gingival tissues both when it was present throughout the growth period of the tissue and when it was added to established tissue at day 8. Zidovudine treatment increased the expression of cytokeratin 10, PCNA and cyclin A. Conversely, cytokeratins 5, involucrin and cytokeratin 6 expression was decreased. The tissue exhibited characteristics of increased proliferation in the suprabasal layers as well as an increased fragility and an inability to heal itself. Conclusions Zidovudine treatments, even when applied in low concentrations for short periods of time, deregulated the cell cycle/proliferation and differentiation pathways resulting in abnormal epithelial repair and proliferation. Our system could be developed as a potential model for studying HIV/ highly active antiretroviral therapy affects in vitro. PMID:22276657

  13. An antiretroviral regimen containing 6 months of stavudine followed by long-term zidovudine for first-line HIV therapy is optimal in resource-limited settings: a prospective, multicenter study in China.

    PubMed

    Li, Taisheng; Guo, Fuping; Li, Yijia; Zhang, Chengda; Han, Yang; Lye, Wei; He, Yun; Lu, Hongzhou; Xie, Jing; Huang, Aiqiong; Li, Yanling; Tang, Xiaoping; Wang, Hui; Zhang, Tong; Gao, Guiju; Lei, Junkang; Zhang, Xiaoying; Wu, Xinhua; Sun, Yongtao; Bai, Jinsong; Luo, Ling; Wang, Huanling

    2014-01-01

    An zidovudine (AZT)-substitution regimen containing 24-week stavudine (d4T) followed by long-term AZT for HIV therapy is potential to trade off short-term AZT-related anemia and long-term risks associated with d4T in resource-limited settings. However, evidence is scarce. This study aims to assess the efficacy and safety of AZT-substitution regimen, aiming to find a regimen with better efficacy, less adverse events, and more affordability in resource-limited settings. This prospective, multicenter study enrolled 499 (190 on d4T regimen, 172 on AZT regimen, and 137 on AZT-substitution regimen) HIV-1-infected subjects who initiated combined antiretroviral therapy and attended follow-up visits over 96 weeks from 2009 to 2011. Lamivudine (3TC) and either nevirapine (NVP) or efavirenz (EFV) were the other two drugs in the antiretroviral regimens. Virologic and immunologic responses and adverse events were monitored at baseline and at weeks 4, 12, 24, 36, 48, 60, 72, 84, and 96. In terms of hematological adverse effects, AZT-substitution group had similar safety profiles to d4T group and was superior to AZT group. In comparison with AZT-substitution group, AZT group was associated with higher risk of developing anemia (adjusted hazard ratio (aHR) for anemia ≥ grade II, 8.44, 95% CI 1.81-39.46) and neutropenia (aHR for neutropenia ≥ grade II, 1.86, 95% CI 1.19-2.93). The prevalence of lipodystrophy in d4T group was 19.5%, while that in AZT-substitution group was zero. As to antiretroviral efficacy, these three groups showed no differences. AZT-substitution regimen provides a relatively safe and effective first-line antiretroviral strategy in resource-limited settings.

  14. Naringin improves zidovudine- and stavudine-induced skeletal muscle complications in rats.

    PubMed

    Adebiyi, O O; Adebiyi, O A; Owira, Pmo

    2016-03-22

    Chronic use of nucleoside reverse transcriptase inhibitors (NRTIs) in managing human immunodeficiency virus (HIV) infection has been associated with several complications. Available management options for these complications have yielded controversial results, thus the need to urgently find newer alternatives. Naringin, a plant-derived flavonoid, has been shown to possess antioxidant and antiapoptotic properties which can be exploited in managing NRTI-induced complications. This study therefore investigated the effects of naringin on some NRTI-induced complications. Forty-nine rats (200-250 g) were divided into seven groups and were orally treated with stavudine (d4T)-only, d4T + naringin, d4T + vitamin E, zidovudine (AZT)-only, AZT + naringin, AZT + vitamin E, and distilled water, respectively. Drugs were administered once daily for 56 days, and oral glucose tolerance tests conducted on day 54 of the experiments and rats were thereafter sacrificed on day 56 by halothane overdose. Plasma samples and the left gastrocnemius muscles were stored at -80°C for further analysis. There was significant glucose intolerance, insulin resistance, oxidative stress, and apoptosis in the skeletal muscles of AZT- or d4T-only-treated rats. Naringin, however, significantly reduced fasting blood glucose and fasting plasma insulin concentrations, mitigated glucose intolerance, and insulin resistance in addition to reducing malondialdehyde and carbonyl protein concentrations when coadministered with either NRTIs. Furthermore, naringin improved antioxidant enzyme activities, reduced skeletal muscle BCL-2-associated X protein expression, and improved B-cell lymphoma-2 protein expression compared to AZT- or d4T-only-treated rats. Naringin ameliorated AZT- and d4T-induced complications and therefore should be further investigated as a possible nutritional supplement in managing HIV infection.

  15. Simultaneous determination of abacavir and zidovudine from rat tissues using HPLC with ultraviolet detection.

    PubMed

    Lewis, Summer R; White, Catherine A; Bartlett, Michael G

    2007-05-01

    A simple high-performance liquid chromatography (HPLC) method has been developed and validated for the simultaneous determination of abacavir and zidovudine (AZT) in rat plasma, amniotic fluid, fetal, and placental tissues. Extraction of abacavir, AZT, and the internal standard, azidouridine (AZDU) in amniotic fluid was carried out by protein precipitation. Extraction from plasma, fetal and placental homogenates was achieved by using a salting out technique. Chromatographic separation was performed using a C8 column (150 mm x 4.6 mm, 5 microm). The mobile phase consisted of 12% acetonitrile in 25 mM sodium phosphate buffer (adjusted to pH 7 with sodium hydroxide) for the fetus, placenta, plasma and amniotic fluid samples at a flow rate of 0.8 mL/min. The method was validated over the range from 0.05 to 50 microg/mL for both abacavir and AZT in the four biological matrices. The absolute recovery of abacavir ranged from 79 to 94%, while AZT recoveries ranged from 79 to 90% in the different biological matrices. The internal standard recovery ranged from 90 to 92%. Acceptable intra- and inter-day assay precision (<10% R.S.D.) and accuracy (<10% error) were observed over 0.05-50 microg/mL for all four matrices.

  16. Fourier transform infrared spectra and normal mode analysis of drug molecules: Zidovudine

    NASA Astrophysics Data System (ADS)

    Jain, Nivedita; Prabhakar, Santosh; Singh, R. A.

    2013-03-01

    The FTIR spectra of zidovudine molecule have been recorded in the range 4000-400 cm-1. The title compound is used as a drug against AIDS or HIV. The molecular structure, fundamental vibrational frequencies and intensities of vibrational bands are evaluated using density functional theory (DFT) using BLYP, B3LYP, B3PW91 and MPW1PW91 methods with 6-31+G(d,p) standard basis set. Comparison of simulated spectra with the experimental spectrum provides important informations and the ability of the computational method to describe the vibrational modes. These calculations have allowed finding most stable conformational structure of AZT. Calculated results of the title compound indicate that the drug molecule has syn orientation. The glycosidic bond in AZT and a minimum-energy structure in which the glycosy torsion angle χ and torsion angle γ values are consistent with those in the conformation of AZT in the AZT5-triphosphate bound to HIV RT is determined.

  17. Silibinin mitigates zidovudine-induced hepatocellular degenerative changes, oxidative stress and hyperlipidaemia in rats.

    PubMed

    Raghu, R; Jesudas, B; Bhavani, G; Ezhilarasan, D; Karthikeyan, S

    2015-11-01

    Prolonged zidovudine (AZT) treatment in HIV-infected and AIDS patients is shown to induce liver toxicity leading to complications. Therapeutic regimen that could encounter this adverse effect is unavailable and management of toxicity is often symptomatic or is limited to withdrawal of therapy. In the present investigation, we evaluated the alleviating properties of silibinin (SBN), a flavanolignan obtained from Silybum marianum against subacute AZT-induced hepatotoxicity and oxidative stress in rats. AZT treatment (50 mg/kg body weight (b.w.) periorally (p.o.), daily for 45 days) caused highly significant increases in alanine transaminase, alkaline phosphatase, argininosuccinic acid lyase and bilirubin in serum. Oxidative stress is shown by a highly significant increase in lipid peroxidase and total carbonyl content and decrease in catalase and protein thiols in the liver tissue. Hyperlipidaemia is indicated by highly significant increase in total lipids and free fatty acid in serum. Evaluation of liver by haematoxylin and eosin staining shows parenchymal cell enlargement, inflammatory changes and increase in sinusoidal spaces. Simultaneous treatment of SBN (100 mg/kg b.w. p.o., daily for 45 days) significantly protected the liver against hepatotoxicity, oxidative stress and hyperlipidaemia induced by AZT, and this alleviating property is attributed to hepatoprotective, membrane-stabilizing, antioxidant and free radical scavenging properties of SBN.

  18. Mucoadhesive Nanostructured Polyelectrolyte Complexes as Potential Carrier to Improve Zidovudine Permeability.

    PubMed

    Pedreiro, Liliane Neves; Stringhetti, Beatriz; Cury, Ferreira; Gremião, Maria Palmira Daflon

    2016-02-01

    Mucoadhesive drug delivery systems have been widely investigated as a strategic to allow the raising of intestinal residence time of drugs and the intimate contact with the intestinal mucosa, both factors that increase the local concentration gradient. Zidovudine (AZT) mucoadhesive nanostructured polyelectrolyte complexes were obtained by chitosan (CS)-hypromellose phthalate (HP) interactions in order to favor the permeability through biological membranes and the AZT absorption. Particle size and morphology analyses showed the obtaining of nanoparticulate delivery systems, with AZT loaded about of 65%. The characterization by DSC, X-ray diffraction and FTIR showed a new crystalline structure formed in which the drug remained molecularly dispersed, without changing this structure. The reduced release rates in the simulated gastric medium and the control of release rates in simulated intestinal medium of AZT were demonstrated by in vitro release studies. The nanoparticles liquid uptake ability associated to the mucoadhesiveness by electronic interaction between the particles and mucus revealed that the drug delivery system developed in this work is a promising approach to improve the permeation of this drug throughout the intestinal mucosa.

  19. Quantitative determination and sampling of lamivudine and zidovudine residues for cleaning validation in a production area.

    PubMed

    Santoro, Maria Inês Rocha Miritello; Fazio, Tatiana Tatit; Singh, Anil Kumar; Kedor-Hackmann, Erica Rosa Maria

    2007-01-01

    Lamivudine (3TC) and zidovudine (AZT) are systemic antiviral substances extensively used in human immunodeficiency virus (HIV) infected patients. Nowadays, 3TC, AZT, and several other pharmacologically potent pharmaceuticals are manufactured in the same production area. To assure quality of drug products and patient safety, properly validated cleaning methodology is necessary. A carefully designed cleaning validation and its evaluation can ensure that residues of 3TC and AZT will not carry over and cross contaminate the subsequent product. The aim of this study was to validate a simple analytical method for verification of residual 3TC and AZT in equipment used in the production area and to confirm the efficiency of the cleaning procedure. The liquid chromatography method was validated using a Nova-Pak C18 column (3.9 x 150 mm, 4 microm particle size) and methanol-water (20 + 80, v/v) as the mobile phase at a flow rate of 1.0 mL/min. Ultraviolet detection was made at 266 nm. The calibration curve was linear over a concentration range of 2.0-22.0 microg/mL with a correlation coefficient of 0.9998. The detection and quantitation limits were 0.36 and 1.21 microg/mL, respectively. The intra-day and interday precision expressed as relative standard deviation were below 2.0%. The mean recovery of the method was 99.19%. The mean extraction recovery from manufacturing equipment was 83.5%.

  20. Asteroid observations with NCSFCT's AZT-8 telescope

    NASA Astrophysics Data System (ADS)

    Kozhukhov, O. M.; Maigurova, N. V.

    2017-02-01

    The asteroid observations of the small Solar System bodies were carried out with the AZT-8 telescope (D = 0.7 m, f/4) of the National Center of Space Facilities Control and Testing (NCSFCT) during 2010-2013. The telescope is located near Yevpatoria, the observatory code according IAU is B17. The observational program included perturbed main belt asteroids and NEO's for the GAIA FUN-SSO Company. The MPC database contains more than 4500 asteroids positions and magnitudes obtained during this period at AZT-8 telescope. The article presents analysis of the positional accuracy of B17 observations obtained from the comparison with the JPL HORIZONS ephemeris, and data from AstD-yS-2 and NEODyS-2 web services.

  1. Effects of Zidovudine Treatment on Heart mRNA Expression and Mitochondrial DNA Copy Number Associated with Alterations in Deoxynucleoside Triphosphate Composition in a Neonatal Rat Model.

    PubMed

    Snowdin, Jacob W; Hsiung, Chia-Heng; Kesterson, Daniel G; Kamath, Vasudeva G; McKee, Edward E

    2015-10-01

    The prevention of mother-to-child transmission (MTCT) of HIV is a crucial component in HIV therapy. Nucleoside reverse transcriptase inhibitors (NRTIs), primarily 3'-azido-3'-thymidine (AZT [zidovudine]), have been used to treat both mothers and neonates. While AZT is being replaced with less toxic drugs in treating mothers in MTCT prevention, it is still commonly used to treat neonates. Problems related to mitochondrial toxicity and potential mutagenesis associated with AZT treatment have been reported in treated cohorts. Yet little is known concerning the metabolism and potential toxicity of AZT on embryonic and neonatal tissues, especially considering that the enzymes of nucleoside metabolism change dramatically as many tissues convert from hyperplastic to hypertrophic growth during this period. AZT is known to inhibit thymidine phosphorylation and potentially alter deoxynucleoside triphosphate (dNTP) pools in adults. This study examines the effects of AZT on dNTP pools, mRNA expression of deoxynucleoside/deoxynucleotide metabolic enzymes, and mitochondrial DNA levels in a neonatal rat model. Results show that AZT treatment dramatically altered dNTP pools in the first 7 days of life after birth, which normalized to age-matched controls in the second and third weeks. Additionally, AZT treatment dramatically increased the mRNA levels of many enzymes involved in deoxynucleotide synthesis and mitochondrial biogenesis during the first week of life, which normalized to age-matched controls by the third week. These results were correlated with depletion of mitochondrial DNA noted in the second week. Taken together, results demonstrated that AZT treatment has a powerful effect on the deoxynucleotide synthesis pathways that may be associated with toxicity and mutagenesis.

  2. Neurotoxic effects of AZT on developing and adult neurogenesis

    PubMed Central

    Demir, Meryem; Laywell, Eric D.

    2015-01-01

    Azidothymidine (AZT) is a synthetic, chain-terminating nucleoside analog used to treat HIV-1 infection. While AZT is not actively transported across the blood brain barrier, it does accumulate at high levels in cerebrospinal fluid, and subsequently diffuses into the overlying parenchyma. Due to the close anatomical proximity of the neurogenic niches to the ventricular system, we hypothesize that diffusion from CSF exposes neural stem/progenitor cells and their progeny to biologically relevant levels of AZT sufficient to perturb normal cell functions. We employed in vitro and in vivo models of mouse neurogenesis in order to assess the effects of AZT on developing and adult neurogenesis. Using in vitro assays we show that AZT reduces the population expansion potential of neural stem/progenitor cells by inducing senescence. Additionally, in a model of in vitro neurogenesis AZT severely attenuates neuroblast production. These effects are mirrored in vivo by clinically-relevant animal models. We show that in utero AZT exposure perturbs both population expansion and neurogenesis among neural stem/progenitor cells. Additionally, a short-term AZT regimen in adult mice suppresses subependymal zone neurogenesis. These data reveal novel negative effects of AZT on neural stem cell biology. Given that the sequelae of HIV infection often include neurologic deficits—subsumed under AIDS Dementia Complex (Brew, 1999)—it is important to determine to what extent AZT negatively affects neurological function in ways that contribute to, or exacerbate, ADC in order to avoid attributing iatrogenic drug effects to the underlying disease process, and thereby skewing the risk/benefit analysis of AZT therapy. PMID:25852464

  3. Evaluation of Microemulsion and Lamellar Liquid Crystalline Systems for Transdermal Zidovudine Delivery.

    PubMed

    Carvalho, André Luis Menezes; Silva, José Alexsandro da; Lira, Ana Amélia Moreira; Conceição, Tamara Matos Freire; Nunes, Rogéria de Souza; de Albuquerque Junior, Ricardo Luiz Cavalcanti; Sarmento, Victor Hugo Vitorino; Leal, Leila Bastos; de Santana, Davi Pereira

    2016-07-01

    This study proposed to investigate and to compare colloidal carrier systems containing Zidovudine (3'-azido-3'-deoxythymidine) (AZT) for transdermal administration and optimization of antiretroviral therapy. Microemulsion (ME) and lamellar phase (LP) liquid crystal were obtained and selected from pseudoternary diagrams previously developed. Small-angle X-ray scattering and rheology analysis confirmed the presence of typical ME and liquid crystalline structures with lamellar arrangement, respectively. Both colloidal carrier systems, ME, and LP remained stable, homogeneous, and isotropic after AZT addition. In vitro permeation study (using pig ear skin) showed that the amount of permeated drug was higher for ME compared to the control and LP, obtaining a permeation enhancing effect on the order of approximately 2-fold (p < 0.05). Microscopic examination after in vivo skin irritation studies using mice suggested few histological changes in the skin of animals treated with the ME compared to the control group (hydrogel). Thus, ME proved to be adequate and have promising effects, being able to promote the drug permeation without causing apparent skin irritation. On the order hand, LP functioned as a drug reservoir reducing AZT partitioning into the skin.

  4. [Placental villous lesions in HIV-1 infection treated with zidovudine].

    PubMed

    Castejón, Olivar C; López, Angela J; Pérez Ybarra, Luis M; Castejón, Oliver C

    2011-05-01

    HIV-1 reaches the placenta through the maternal-fetal transmission from an infected uterus. This virus has cytolytic capabilities. The placenta in its maturation process has regressive or degenerative changes within certain limits, are considered normal. However, factors such as virus and antiretrovirals, can increase the proportion of these lesions. To evaluate morphological changes in placental villi of pregnant women infected with HIV-1 treated with AZT. descriptive, prospective, comparative, with non-probability sampling of observations in villi as units of analysis of the placentas from the group of patients with HIV-1 infection and zidovudine regimen and of the control group of four placentas from HIV negative patients. Both groups in the last trimester of pregnancy. H-E staining was used in 25 films from five placental regions of the study group and four from the control group, using a protocol of 6 variables identifying syncytial knots, fibrinoid changes, villous edema, stromal fibrosis, calcification and villous immaturity. Observations were analyzed using ANOVA as a 2 x 5 factorial arrangement with 4 replications subsampling and split plot design and Tukey test. Chorionic villi showed percentages of alterations that exceed the normal range. It showed significant differences (p<0.05) between the placentas exposed to HIV-1 and AZT and normal placentas in relation to the percentage of villi affected by 5 variables, except fibrosis. The lesions may be increasing the vertical transmission of HIV-1. We also found evidence that the placenta is not in the best conditions for the transfer of gases, nutrients and metabolites, which could promote a decrease in birth weight and placental weight.

  5. Short-course AZT reduces HIV transmission to infants; Glaxo cuts AZT price for developing countries.

    PubMed

    Baker, R

    1998-04-01

    A four-week AZT treatment recently tested by the Centers for Disease Control and Prevention (CDC) and health officials in Thailand revealed reductions in mother-to-infant transmission by 50 percent. The treatment offers hope to HIV-positive pregnant women in developing countries who do not have access to the full-course treatment common in the United States. Critics have charged that the study was unethical because some women were given placebos. The manufacturer, Glaxo Wellcome, is dropping AZT prices by 75 percent. The drug treatment and testing will cost about $100, instead of the $800 to $1,000 that the full treatment costs. Even with the price break, many feel that developed countries will need to heavily subsidize the programs to reduce the number of infant infections, now estimated at 550,000 per year.

  6. Metabolism and pharmacokinetics of the combination Zidovudine plus Lamivudine in the adult Erythrocebus patas monkey determined by liquid chromatography-tandem mass spectrometric analysis

    SciTech Connect

    Divi, Rao L.; Doerge, Daniel R.; Twaddle, Nathan C.; Shockley, Marie E.; St Claire, Marisa C.; Harbaugh, Jeffrey W.; Harbaugh, Steven W.; Poirier, Miriam C.

    2008-01-15

    Because of their similarity to humans, non-human primates constitute useful preclinical models in which to examine potential human drug toxicities. Antiretroviral nucleoside reverse transcriptase inhibitor (NRTI) toxicity is currently under investigation in Erythrocebus patas monkeys, and whereas NRTI pharmacokinetics have been studied in other monkey species, pharmacokinetics for Zidovudine plus Lamivudine (AZT/3TC) dosing have not been reported in the patas. Here we present 24 h serum pharmacokinetic parameters after a single oral exposure to the combination of AZT (40 mg) and 3TC (24 mg), doses equivalent to a human daily dose of Combivir (registered) . The patas (n = 3) AZT/3TC pharmacokinetic profiles were similar to those seen in other primate species. Average maximum serum concentrations (C{sub max}) for AZT and 3TC were 2.35 and 2.65 {mu}g/ml, respectively, and were observed at 0.83 h (T{sub max}). C{sub max} was 13.34 {mu}g/ml for the AZT-glucuronide (AZT-G) and was 0.023 {mu}g/ml for the potentially toxic minor metabolite 3'-amino-3'-deoxythymidine (AMT), both occurring at about 1 h after dosing. Similar elimination half-times, 0.70 and 0.68 h{sup -1}, were found for AZT and AZT-G, respectively, while 3TC was eliminated about half as fast (0.33 h{sup -1}) resulting in AUC{sub (0-{infinity})} values of 6.97 {mu}g/ml h for 3TC, 2.99 {mu}g/ml h for AZT, 20.5 {mu}g/ml h for AZT-G and 0.002 for AMT 6.97 {mu}g/ml h. This study shows similar metabolism and pharmacokinetics for oral administration of AZT/3TC in the adult patas monkey, other primate species and humans. The data validate the use of the patas monkey for studies of NRTI toxicity.

  7. New sustained release of zidovudine matrix tablets - cytotoxicity toward Caco-2 cells.

    PubMed

    Santos, Jucimary V; Pina, Maria Eugénia T; Marques, M Paula M; de Carvalho, Luís A E Batista

    2013-08-01

    The aim of this study was to adjust the zidovudine (AZT) release from solid tablets to an ideal profile, by developing matrices comprising swellable polymers with nonswellable ones. Directly compressed matrices comprised different ratios of hydroxypropylmethylcellulose K15M and K100M, ethylcellulose, and methacrylic acid (Eudragit(®) RS PO and Eudragit(®) RL PO) were prepared. Technological characterization and evaluation of the in vitro release behavior were carried out. Cell density and viability following drug exposure were evaluated by the SRB method, for the Caco-2 line, while cell morphology was assessed upon Trypan blue staining. A specific formulation containing 5% of each excipient - HPMC K15M, HPMC K100M, Eudragit(®) RS PO, and Eudragit(®) RL PO - was found to yield the best release profile. Application of the Korsmeyer-Peppas model to the dissolution profile evidenced that a non-Fickian (anomalous) transport is involved in the drug release. Regarding the influence of the tablets' composition on the drug's cytotoxic effect toward the Caco-2 cell line, a reduction of cell biomass (0-15%) was verified for the distinct AZT formulations tested, F19 having displayed the highest cytotoxicity, after 24 and 48 h of incubation. Additionally, a high reversibility of the AZT effect was observed. The results showed that the simultaneous application of both hydrophilic and hydrophobic polymers can modulate the drug release process, leading to an improved efficacy and patient compliance. All AZT formulations studied were found to be cytotoxic against Caco-2 cells, F19 being the most effective one.

  8. Comparative studies of lamivudine-zidovudine nanoparticles for the selective uptake by macrophages.

    PubMed

    Sankar, V; Nareshkumar, Parmar Nilaykumar; Ajitkumar, Gohel Nishit; Penmetsa, Shalini Devi; Hariharan, Sivaram

    2012-09-01

    The present study investigates the specific drug targeting of anti retroviral drugs, such as lamivudine and zidovudine, after intraperitoneal (i.p) injection by incorporation into polymeric nanoparticles (PNs) and solid lipid nanoparticles (SLNs). Our results showed that Glyceryl Monosterate-Poloxamer 188 SLNs (average diameter of 522.466 nm) showed slow drug release rates (63.18% of lamivudine and 62.37% of zidovudine were released in 12 hrs) among all the SLN formulations. For Poly lactic-co-glycolic acid (PLGA)-Poloxamer 188 PNs (average diameter of 70.348 nm), there were faster release rates of both lamivudine and zidovudine (97% and 94.06%, respectively, in 12 hrs). Tissue distribution studies were carried out in mice and concentrations of drugs in different organs were determined using high performance liquid chromatography (HPLC) after i.p. administration. Glyceryl Monosterate-Poloxamer 188 SLNs and PLGA-Poloxamer 188 PNs showed increase in the distribution of lamivudine and zidovudine to liver and spleen when compared to the drugs in solution. Also, Glyceryl Monosterate-P 188 SLNs showed higher concentration of drugs in RES organs than PLGA-P 188 PNs.

  9. [Rapid development of anemia in a HIV-positive patient with alpha-thalassemia after zidovudine therapy].

    PubMed

    Altinbaş, Akif; Ozkaya, Gülşen; Büyükaşik, Yahya; Unal, Serhat

    2007-07-01

    Anemia, which may develop due to direct effect of the virus or indirect effect of zidovudine a widely used antiviral agent for the treatment, is not an uncommon complication in human immundeficiency virus (HIV) infections. In this report, a 26 years old male HIV positive patient who developed rapid anemia in the HAART (Highly active anti-retroviral therapy) protocol including zidovudine, was presented. The patient has been followed since May 2003 without anti-retroviral therapy. He was diagnosed as alpha-thalassemia trait, because of the low mean red blood cell volume (MCV), high red blood cell count and living in an Mediterranian country. However, no treatment for thalassemia had been given in this period, since the other laboratory findings [hemoglobin, hematocrit, red cell distribution width index (RDWI), iron and iron binding capacity, transferrin saturation and ferritin levels] were normal. During the follow-up of patient, HAART protocol with zidovudine, lamivudine and indinavir, was started depending on the findings of low CD4+ T-cell count (443/mm3) and high HIV serum load (1,330,000 copies/ml). In the second month of the therapy the hemoglobin level decreased to 12.9 gr/dL, and then to 9.9 gr/dL in the fourth month, while it was 14.5 gr/dL before anti-retroviral therapy. Although the patient had no hemolysis findings, and his serum folic acid level was normal, folbiol treatment was initiated with the possibility of the presence of folic acid deficiency at cellular level. Anemia resolved with folic acid replacement without discontinuation of zidovudine or a reduction in dosage. It was thought that the presence of alpha-thalassemia co-morbidity has facilitated the development of anti-retroviral-induced anemia in this patient. As a result, it is concluded that thalassemia should be considered in the differential diagnosis of anemia in HIV positive patients, especially for the ones from Mediterranian countries.

  10. Development and characterization of PLGA nanoparticles as delivery systems of a prodrug of zidovudine obtained by its conjugation with ursodeoxycholic acid.

    PubMed

    Dalpiaz, Alessandro; Contado, Catia; Mari, Lara; Perrone, Daniela; Pavan, Barbara; Paganetto, Guglielmo; Hanuskovà, Miriam; Vighi, Eleonora; Leo, Eliana

    2014-05-01

    Zidovudine (AZT) is employed against AIDS and hepatitis; its use is limited by active efflux transporters (AETs) that induce multidrug resistance for intracellular therapies and hamper AZT to reach the brain. Ursodeoxycholic acid (UDCA) conjugation with AZT (prodrug UDCA-AZT) allows to elude the AET systems. To investigate the effect of the Pluronic F68 coating on the loading, release and stability of poly(D,L lactide-co-glicolide) nanoparticles (NPs) embedded with UDCA-AZT. The mean diameter of the NP prepared by nanoprecipitation or emulsion/solvent evaporation methods was determined using both photon correlation spectroscopy and sedimentation field-flow fractionation; particle morphology was detected by scanning electron microscope. The stability of the free and encapsulated UDCA-AZT was evaluated in rat liver homogenates by high-performance liquid chromatography analysis. The mean diameter of the NPs was found to be ∼ 600 nm with a relatively high polydispersity. The NPs obtained by emulsion/solvent evaporation were not able to control the prodrug release, differently from NPs obtained by nanoprecipitation. The presence of the Pluronic coating did not substantially modify the kinetics of the drug release, or the extent of the burst effect that were instead only influenced by the preparation parameters. UDCA-AZT incorporated in the NPs was more stable in the rat liver homogenates than the free prodrug and no influence of the Pluronic coating was observed. Considering the different potential applications of nanoparticles coated and uncoated with Pluronic (brain and macrophage targeting, respectively), both of these nanoparticle systems could be useful in the therapies against HIV.

  11. Durability of initial antiretroviral therapy in a resource-constrained setting and the potential need for zidovudine weight-based dosing.

    PubMed

    Willig, James H; Echevarria, Juan; Westfall, Andrew O; Iglesias, David; Henostroza, German; Seas, Carlos; Mugavero, Michael J; Allison, Jeroan; Paz, Jorge; Hernandez, Fiorella; Tomatis, Cristina; Saag, Michael S; Gotuzzo, Eduardo

    2010-02-01

    Whereas access to antiretroviral therapy (ART) for HIV-infected individuals in the developing world is increasing, data on factors impacting initial regimen durability are lacking. Retrospective review patients starting initial ART at Instituto de Medicine Tropical (Lima, Peru) April 1, 2004 to December 30, 2007. Survival methods (Kaplan-Meier, Cox proportional hazard) assessed factors associated with regimen durability including an interaction term between nucleoside reverse transcriptase inhibitor backbone and time. Decreased initial regimen durability was observed with weight <60 kg [hazards ratio (HR) = 1.77; 95% confidence interval (CI) = 1.25-2.51], CD4 <200 (HR = 1.73; 95% CI = 1.03-2.91), and zidovudine (AZT) use at <120 days (HR = 2.09; 95% CI = 1.22-3.57). In contrast, after 120 days, AZT use decreased risk of discontinuation (HR = 0.52; 95% CI = 0.28-0.95). Early (<120 days) toxicity-related discontinuation of AZT containing regimens was observed in 44% of patients <50 kg at baseline vs. 14% of those >70 kg. An increased risk of early toxicity-related discontinuation of AZT-containing regimens was observed for baseline weight <60 kg (HR = 2.52; 95% CI = 1.46-4.35). Lower baseline weight and lower CD4 values at ART initiation were associated with decreased regimen durability. Compared with didanosine/stavudine, AZT use initially increased, then subsequently (>120 days) lowered hazards for regimen discontinuation. Weight <60 kg was associated with an increased risk of toxicity-related AZT discontinuation. As ART use expands globally, further study into maximally durable, least toxic regimens, and the role of weight-based AZT dosing is imperative.

  12. Warfarin is an effective modifier of multiple UDP-glucuronosyltransferase enzymes: evaluation of its potential to alter the pharmacokinetics of zidovudine.

    PubMed

    Sun, Hua; Zhang, Tianpeng; Wu, Zhufeng; Wu, Baojian

    2015-01-01

    In this study, we aimed to determine the modulatory effects of warfarin (an extensively used anticoagulant drug) and its metabolites on UDP-glucuronosyltransferase (UGT) activity and to assess the potential of warfarin to alter the pharmacokinetics of zidovudine (AZT). The effects of warfarin and its metabolites on glucuronidation were determined using human and rat liver microsomes (HLM and RLM) as well as expressed UGTs. The mechanisms of warfarin-UGT interactions were explored through kinetic characterization and modeling. Pharmacokinetic studies with rats were performed to evaluate the potential of warfarin to alter the pharmacokinetics of AZT. We found that warfarin was an effective modifier of a panel of UGT enzymes. The effects of warfarin on glucuronidation were inhibitory for UGT1A1, 2B7, and 2B17, but activating for UGT1A3. Mixed effects were observed for UGT1A7 and 1A9. Consistent with its inhibitory effects on UGT2B7 activity, warfarin inhibited AZT glucuronidation in HLM (Ki = 74.9-96.3 μM) and RLM (Ki = 190-230 μM). Inhibition of AZT glucuronidation by UGT2B7, HLM, and RLM was also observed with several hydroxylated metabolites of warfarin. Moreover, the systemic exposure (AUC) of AZT in rats was increased by a 1.5- to 2.1-fold upon warfarin coadministration. The elevated AUC was associated with suppressed glucuronidation that was probably attained through a combined action of warfarin and its hydroxylated metabolites. In conclusion, the activities of multiple UGT enzymes can be modulated by warfarin and the nature of modulation was isoform dependent. Also, pharmacokinetic interactions of zidovudine with warfarin were highly possible through inhibition of UGT metabolism.

  13. Human Serum Albumin Complexed with Myristate and AZT

    SciTech Connect

    Zhu, Lili; Yang, Feng; Chen, Liqing; Meehan, Edward J.; Huang, Mingdong

    2008-06-16

    3'-Azido-3'-deoxythymidine (AZT) is the first clinically effective drug for the treatment of human immunodeficiency virus infection. The drug interaction with human serum albumin (HSA) has been an important component in understanding its mechanism of action, especially in drug distribution and in drug-drug interaction on HSA in the case of multi-drug therapy. We present here crystal structures of a ternary HSA-Myr-AZT complex and a quaternary HSA-Myr-AZT-SAL complex (Myr, myristate; SAL, salicylic acid). From this study, a new drug binding subsite on HSA Sudlow site 1 was identified. The presence of fatty acid is needed for the creation of this subsite due to fatty acid induced conformational changes of HSA. Thus, the Sudlow site 1 of HSA can be divided into three non-overlapped subsites: a SAL subsite, an indomethacin subsite and an AZT subsite. Binding of a drug to HSA often influences simultaneous binding of other drugs. From the HSA-Myr-AZT-SAL complex structure, we observed the coexistence of two drugs (AZT and SAL) in Sudlow site 1 and the competition between these two drugs in subdomain IB. These results provide new structural information on HSA-drug interaction and drug-drug interaction on HSA.

  14. Analysis of the Zidovudine Resistance Mutations T215Y, M41L, and L210W in HIV-1 Reverse Transcriptase.

    PubMed

    Boyer, Paul L; Das, Kalyan; Arnold, Eddy; Hughes, Stephen H

    2015-12-01

    Although anti-human immunodeficiency virus type 1 (HIV-1) therapies have become more sophisticated and more effective, drug resistance continues to be a major problem. Zidovudine (azidothymidine; AZT) was the first nucleoside reverse transcriptase (RT) inhibitor (NRTI) approved for the treatment of HIV-1 infections and is still being used, particularly in the developing world. This drug targets the conversion of single-stranded RNA to double-stranded DNA by HIV-1 RT. However, resistance to the drug quickly appeared both in viruses replicating in cells in culture and in patients undergoing AZT monotherapy. The primary resistance pathway selects for mutations of T215 that change the threonine to either a tyrosine or a phenylalanine (T215Y/F); this resistance pathway involves an ATP-dependent excision mechanism. The pseudo-sugar ring of AZT lacks a 3' OH; RT incorporates AZT monophosphate (AZTMP), which blocks the end of the viral DNA primer. AZT-resistant forms of HIV-1 RT use ATP in an excision reaction to unblock the 3' end of the primer strand, allowing its extension by RT. The T215Y AZT resistance mutation is often accompanied by two other mutations, M41L and L210W. In this study, the roles of these mutations, in combination with T215Y, were examined to determine whether they affect polymerization and excision by HIV-1 RT. The M41L mutation appears to help restore the DNA polymerization activity of RT containing the T215Y mutation and also enhances AZTMP excision. The L210W mutation plays a similar role, but it enhances excision by RTs that carry the T215Y mutation when ATP is present at a low concentration.

  15. [Evaluation of tolerance of zidovudine-lamivudine-nevirapine combination in HIV 1 patients in Fann Teaching Hospital in Dakar].

    PubMed

    Fortes Déguénonvo, L; Diop, S A; Leye, M M M; Seydi, M; Dieng, A B; Bentaleb, H; Diouf, A; Lakhe, N A; Ka, D; Cisse, V M P; Dia Badiane, N M; Manga, M N; Ndour, C T; Soumaré, M; Diop, B M; Sow, P S

    2013-10-01

    We conducted a study to evaluate the tolerance of the zidovudine (AZT), lamivudine (3TC) and nevirapine (NVP) combination regimen in HIV-1 patients by a descriptive analytical retrospective study of all HIV-1 patients receiving AZT-3TC-NVP combination between 2008 and 2011. Seventy patients were included. Two thirds of the patients presented at least one side effect (44 cases). The digestive disorders (15 cases) and neuropsychiatric (14 cases) were the most frequent. Epigastralgia (20%), headaches (20%) and arthralgias (13%) were main side effects. A maculo-papular exanthema was noted in three cases. During the follow-up, five patients presented with anemia. No patient presented hepatic cytolysis due to NVP. All the patients followed for more than six months presented a side effect against 29.7% when the duration of treatment was equal to or less than 6 months (p=10(-5)). Most of the side effects due to the association AZT/3TC/NVP are minor. The evaluation of the clinical and biological tolerance must be maintained during all the follow-up.

  16. Retroviral DNA Integration

    PubMed Central

    2016-01-01

    The integration of a DNA copy of the viral RNA genome into host chromatin is the defining step of retroviral replication. This enzymatic process is catalyzed by the virus-encoded integrase protein, which is conserved among retroviruses and LTR-retrotransposons. Retroviral integration proceeds via two integrase activities: 3′-processing of the viral DNA ends, followed by the strand transfer of the processed ends into host cell chromosomal DNA. Herein we review the molecular mechanism of retroviral DNA integration, with an emphasis on reaction chemistries and architectures of the nucleoprotein complexes involved. We additionally discuss the latest advances on anti-integrase drug development for the treatment of AIDS and the utility of integrating retroviral vectors in gene therapy applications. PMID:27198982

  17. Influence of 3-aminobenzamide, an inhibitor of poly(ADP-ribose)polymerase, in the evaluation of the genotoxicity of doxorubicin, cyclophosphamide and zidovudine in female mice.

    PubMed

    Yadav, L; Khan, S; Shekh, K; Jena, G B

    2014-08-01

    Testing new chemical entities for genotoxicity is an integral part of the preclinical drug-development process. Lowering the detection limit and enhancing the sensitivity of genotoxicity assays is required, as the standard test-battery fails to detect some carcinogens (non-genotoxic) and weak genotoxins. One of the mechanisms that affect the detection of weak genotoxins is related with the DNA-repair efficiency of the cell system used. In the present study, 3-aminobenzamide (3-AB, 30 mg/kg body-weight), a poly(ADP-ribose)polymerase inhibitor, was used to evaluate the DNA-damaging potential of zidovudine (AZT, 400 mg/kg bw), doxorubicin (DOX, 5 mg/kg bw) and cyclophosphamide (CP, 50 mg/kg bw, as a positive control) and sucrose (SUC, 3 g/kg bw, as a negative control) in Swiss female mice. The endpoints considered included micronucleus formation, DNA breakage (in peripheral blood lymphocytes, bone marrow and liver; comet assay) and chromosome aberrations, as well as immunohistochemistry of PARP-1 and phosphorylated histone H2AX (γ-H2AX). The results clearly indicate that the genotoxicity of zidovudine (AZT), doxorubicin (DOX) and cyclophosphamide (CP) was significantly increased in the combination treatments (3-AB+AZT, 3-AB+DOX, 3-AB+CP) as compared with the respective controls (treatment with AZT, DOX and CP alone). There was no increase in the genotoxicity per se after treatment with SUC, 3-AB or 3-AB+SUC, compared with the control (saline). Correlation analysis suggests that all genotoxicity parameters are well correlated with each other. The results clearly show that the genotoxicity of weak genotoxins can be enhanced and detected in the presence of 3-AB in mice. Thus, this approach can be used in the pre-clinical genotoxicity screening of weak genotoxins.

  18. Zidovudine use in pregnancy and congenital malformations.

    PubMed

    Rough, Kathryn; Sun, Jenny W; Seage, George R; Williams, Paige L; Huybrechts, Krista F; Bateman, Brian T; Hernandez-Diaz, Sonia

    2017-07-31

    There is inconsistent evidence that zidovudine use during pregnancy increases overall, cardiac, and male genital malformations. We conducted a systematic review and meta-analysis of zidovudine use and malformations and, using Bayesian methods, combined it with data from a cohort study of mother-infant pairs in the nationwide Medicaid Analytic eXtract (MAX). Using MAX data (2000-2010), we identified pregnant women with HIV treated with antiretroviral therapy (ART). Women with at least one zidovudine dispensing during the first trimester were compared to women receiving ART without zidovudine in the first trimester. Malformation outcomes were defined using diagnosis/procedure codes. To adjust for confounding, we performed 1 : 1 propensity score matching. Bayesian methods require specification of a prior, which we developed in the meta-analysis. Logistic regression models combined MAX data with the prior, estimating odds ratios (ORs) and 95% credible intervals. Fourteen articles contributed information on overall malformations, seven on cardiac malformations, and five on male genital malformations. In MAX, matching led to a sample of 735 women each in the zidovudine and comparator groups. When comparing first trimester zidovudine use to other ART, the Bayesian procedure yielded OR estimates slightly above the null for overall [OR = 1.11, 95% credible interval (0.80-1.55)] and cardiac [OR = 1.30 (0.63-2.71)] malformations. There were no zidovudine-exposed cases of male genital malformations in MAX, but the meta-analysis yielded elevated OR estimates [OR = 2.57 (1.26-5.24)]. For most malformations, first-trimester zidovudine was not associated with increased risk. The potential increase in male genital malformations was small in absolute terms, and should be evaluated further.

  19. Zidovudine and interferon-alpha treatment induces a high response rate and reduces HTLV-1 proviral load and VEGF plasma levels in patients with adult T-cell leukemia from North East Iran.

    PubMed

    Kchour, Ghada; Makhoul, Nadine J; Mahmoudi, Mahmoud; Kooshyar, Mohamad-Mehdi; Shirdel, Abbas; Rastin, Maryam; Rafatpanah, Houshang; Tarhini, Mahdi; Zalloua, Pierre A; Hermine, Olivier; Farid, Reza; Bazarbachi, Ali

    2007-02-01

    Human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukemia/lymphoma (ATLL) is endemic in southern Japan, the Caribbean, intertropical Africa, and Brazil. Recently north east Iran, particularly the region of Mashhad, has been recognized as a new endemic region. ATLL is an aggressive T-cell lymphoproliferative disorder. Patients with ATLL have high plasma levels of VEGF that induce angiogenesis. Prognosis of ATLL remains poor because of immunosuppression and intrinsic resistance to chemotherapy. Important advances in the treatment of ATLL were reported with the combination of zidovudine (AZT) and interferon-alpha. We investigated the effect of AZT/IFN treatment on vascular endothelium growth factor (VEGF) plasma levels and HTLV-I proviral load in ATLL patients from the region of Mashhad. We confirmed that AZT/IFN treatment induces a high response rate and prolonged survival with minimal side effects. We also confirmed that VEGF plasma levels and HTLV-I proviral load are higher in ATLL patients than in asymptomatic carriers. We finally showed that AZT/IFN treatment reduced both HTLV-I proviral load and importantly VEGF plasma levels, suggesting a potential antiangiogenic effect of this therapy. These results provide further evidence for the efficacy and the mechanism of action of AZT/IFN therapy for ATLL in a developing country.

  20. 3′-Azido-3′-deoxythymidine (AZT) inhibits thymidine phosphorylation in isolated rat liver mitochondria: A possible mechanism of AZT hepatotoxicity

    PubMed Central

    Lynx, Matthew D.; Bentley, Alice T.; McKee, Edward E.

    2006-01-01

    3′-Azido-3′-deoxythymidine (AZT) is a staple of highly active antiretroviral therapy (HAART). Prior to HAART, long-term use of high-dosage AZT caused myopathy, cardiomyopathy, and hepatotoxicity, associated with mitochondrial DNA depletion. As a component of HARRT, AZT causes cytopenias and lipodystrophy. AZT-5′-triphosphate (AZTTP) is a known inhibitor of the mitochondrial polymerase γ and has been targeted as the source of the mitochondrial DNA depletion. However, in previous work from this laboratory with isolated rat heart mitochondria, AZT phosphorylation beyond AZT-5′-monophosphate (AZTMP) was not detected. Rather, AZT was shown to be a more potent inhibitor of thymidine phosphorylation (50% inhibitory concentration (IC50) of 7.0 ± 1.0 μM) than AZTTP is of polymerase γ (IC50 of >100 μM), suggesting that depletion of mitochondrial stores of TTP may limit replication. This work has investigated whether an identical mechanism might account for the hepatotoxicity seen with long-term use of AZT. Isolated rat liver mitochondria were incubated with labeled thymidine or AZT, and the rate and extent of phosphorylation were determined by HPLC analysis of acid-soluble extracts of the incubated mitochondria. The results showed that in the phosphorylation of thymidine to TMP, liver mitochondria exhibit a higher Vmax and Km than heart mitochondria, but otherwise heart and liver mitochondria display similar kinetics. AZT is phosphorylated to AZTMP, but no further phosphorylated forms were detected. In addition, AZT inhibited the production of TTP, with an IC50 of 14.4 ± 2.6 μM AZT. This is higher, but comparable to, the results seen in isolated rat heart mitochondria. PMID:16472780

  1. Reverse transcriptase sequence of paired isolates of cerebrospinal fluid and blood from patients infected with human immunodeficiency virus type 1 during zidovudine treatment.

    PubMed Central

    Di Stefano, M; Sabri, F; Leitner, T; Svennerholm, B; Hagberg, L; Norkrans, G; Chiodi, F

    1995-01-01

    Human immunodeficiency virus type 1 (HIV-1) isolates obtained from the blood of patients undergoing treatment with 3'-azido-3'-deoxythymidine (zidovudine [AZT]) show a decreased sensitivity to the drug in vitro. The aim of the present study was to determine if HIV-1 variants resistant to AZT are present also in the brain compartment. We selected sequential HIV-1 isolates from the blood and the cerebrospinal fluid (CSF) of six patients with HIV-1 infection undergoing AZT therapy for a time varying between 1 and 3 years. The isolates were used to infect peripheral blood mononuclear cell cultures which were used to prepare viral DNA. The viral DNA was amplified by PCR and then directly sequenced. Analysis of the reverse transcriptase (RT) sequence of the isolates from the CSF during therapy demonstrated that CSF-resistant isolates are characterized by the same mutations documented in resistant isolates from the blood compartment. Isolates obtained from one patient (patient 3) showed the same two mutations (codons 70 and 215) in blood and CSF, whereas isolates obtained from an additional four patients presented a different pattern of mutations in the two compartments. We also analyzed the degree of amino acid homology between RT sequences from blood and CSF isolates in patients before and during AZT treatment. The percentages of amino acid variations were approximately equal when isolates from the same or different compartments were considered. Excluding the codons involved in AZT resistance, the time point of sampling did not affect RT variations during therapy significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7536214

  2. An unusual phenotypic and genotypic expression in F2 generation following one stage zidovudine exposure during pregnancy and lactation- an experiment in mice.

    PubMed

    Rajlakshmi, Chongtham; Roy, Jagat Kumar; Rai, Amit Kumar; Bhattacharyya, Asima; Pandey, Bajarang Lal

    2012-02-01

    Zidovudine (3'-Azido-2', 3'-dideoxythymidine, AZT, ZDV) is routinely used as one of the component of antiretroviral therapy to prevent transmission of the HIV infection from mother to child. The drug, when given during pregnancy can give rise to myriad toxicities as reported in previous studies on human, animal and in-vitro experiments. The present study was an attempt to explore the Zidovudine teratogenesis in F1 and F2 generation of mice following initial maternal exposure to Zidovudine during pregnancy, through delivery and lactation. The F1 generation actually would have got the exposure during embryonic development and infant stages. Pregnant Swiss mice were treated orally with ZDV 50 mg/kg/day or distilled water (control), from day eighth of gestation, through delivery and continued for first ten days of lactation. The F1 generation litters were raised and mated to produce F2 generation mice. An interesting phenotype of "healthy" and "sick" was noted in F2 generation but not in the F1 generation. In F2 generation 35% died on different postnatal day during 120 days of follow up period. Chromosomal study from bone marrow of F1 and F2 showed various chromosomal aberrations. Lipodystrophy and hepatotoxicity was observed in "sick" mice. The study generated a hypothesis of recessive mutation and concludes that Zidovudine is a transplacental genotoxic agent. The result of present study therefore suggests the need to study the effect of zidovudine in human subjects for a longer period of time to rule out similar genotoxic effect.

  3. Frequency of Hprt mutant lymphocytes and micronucleated erythrocytes in p53-haplodeficient mice treated perinatally with AZT and AZT in combination with 3TC.

    PubMed

    Dobrovolsky, Vasily N; Shaddock, Joseph G; Mittelstaedt, Roberta A; Bishop, Michelle E; Lewis, Sherry M; Lee, Fei W; Aidoo, Anane; Leakey, Julian E A; Dunnick, June K; Heflich, Robert H

    2007-01-01

    Azidothymidine (AZT) is a nucleoside reverse transcriptase inhibitor (NRTI) that is used for reducing mother-to-child transmission of human immunodeficiency virus I. Combinations of AZT and 3'-thiacytidine (3TC) are even more effective than AZT alone. AZT, however, is a mutagen and carcinogen in rodent models and 3TC can increase the genotoxicity of AZT. Since p53 plays a key role in human and mouse tumorigenesis, p53-haplodeficient mice are currently being evaluated as a model for assessing the carcinogenicity of perinatal exposure to NRTIs. In the present study, male C57BL/6 p53(+/+) and p53(-/-) mice were mated with C3H p53(+/+) females; the pregnant females were treated on gestation day 12 through parturition with 40, 80, and 160 mg/kg of AZT or a combination of 160 mg/kg AZT and 100 mg/kg 3TC (AZT-3TC); the p53(+/+) and p53(+/-) offspring were treated daily after birth through postnatal day (PND) 28. The frequencies of micronucleated reticulocytes (MN-RETs) and micronucleated normochromatic erythrocytes (MN-NCEs) were determined on PND1, PND10, and PND28; the frequency of Hprt mutant lymphocytes was measured on PND28. The frequencies of MN-RETs and MN-NCEs were increased in treated animals at all time points; there were no differences in the responses of p53(+/+) and p53(+/-) animals treated with identical doses of NRTIs. After correction for clonal expansion, both AZT and AZT-3TC treatments induced small but significant increases in the frequency of Hprt mutant lymphocytes in p53(+/-) mice, but not in p53(+/+) mice. The data indicate that p53 haplodeficiency affects the genotoxicity of NRTIs; thus, p53(+/-) mice may be a sensitive model for evaluating the carcinogenicity of perinatal exposure to NRTIs. (c) 2006 Wiley-Liss, Inc.

  4. Development and validation of a RP-HPLC method for the determination of zidovudine and its related substances in sustained-release tablets.

    PubMed

    dos Santos, Jucimary V; de Carvalho, Luís A E Batista; Pina, M Eugénia

    2011-01-01

    A reversed-phase high-performance liquid chromatography (RP-HPLC) method for the rapid and accurate quantification of zidovudine (AZT) in sustained release tablets during stability testing was developed. A Waters RP-18 XTerra™(®) column, using a water:methanol (80:20, v/v%) mobile phase at a flow rate of 1.0 ml min(-1), and UV detection at 266 nm, was employed. The method of validation parameters indicate a linear range of between 40.0 to 220.0 µg ml(-1) with an LOQ of 1.985 µg ml(-1) and an LOD of 0.655 µg ml(-1) for the analyte. The degradation products of AZT were isolated and characterized for the first time. There was a very little decline of antiviral by heat, and AZT did not completely degrade either by acid or alkaline hydrolysis. On the other hand, oxidation caused a higher degradation stress in the drug. Finally, the degradation products resulting from stress studies were not found to interfere with the detection of antiviral, which is an advantage of the presently proposed method.

  5. Studies on transdermal delivery enhancement of zidovudine.

    PubMed

    Takmaz, Evrim Atilay; Inal, Ozge; Baykara, Tamer

    2009-01-01

    The purpose of this study was to investigate physicochemical characteristics and in vitro release of zidovudine from monolithic film of Eudragit RL 100 and ethyl cellulose. Films included 2.5% or 5% (w/w) zidovudine of the dry polymer weight were prepared in various ratios of polymers by solvent evaporation method from methanol/acetone solvent mixture. The release studies were carried out by vertical Franz cells (2.2 cm(2) area, 20 ml receptor fluid). Ex vivo studies were done on Wistar rat skin within the films F6 (Eudragit RL100) and F7 (Eudragit RL100/Ethylcellulose, 1:1) consisting 5% (w/w) zidovudine in comparison with the same amount of free drug. Either iontophoresis (0.1 and 0.5 mA/cm(2) direct currents, Ag/AgCl electrodes) or dimethyl sulfoxide (pretreatment of 1% and 5%, w/w, solutions) were used as enhancers. Films consisting of ethyl cellulose under the ratio of 50% (w/w) gave similar release profiles, and the highest in vitro cumulative released amount was achieved with F6 film which gave the closest results with the free drug. This result could be due to the high swelling capacity and re-crystallization inhibition effect of RL 100 polymer which also influenced the film homogenization. All the films were fitted to Higuchi release kinetics. It was also observed that both 0.5-mA/cm(2) current and 5% (w/w) dimethyl sulfoxide applications significantly increased the cumulative permeated amount of zidovudine after 8 h; however, the flux enhancement ratio was higher for 0.5-mA/cm(2) current application, especially within F6 film. Thus, it was concluded that Eudragit RL100 film (F6) could be further evaluated for the transdermal application of zidovudine.

  6. Controlled release matrix tablets of zidovudine: effect of formulation variables on the in vitro drug release kinetics.

    PubMed

    Ravi, Punna Rao; Kotreka, Udaya Kanth; Saha, Ranendra Narayan

    2008-01-01

    The purpose of this research was to design oral controlled release (CR) matrix tablets of zidovudine (AZT) using hydroxypropyl methylcellulose (HPMC), ethyl cellulose (EC) and carbopol-971P (CP) and to study the effect of various formulation factors on in vitro drug release. Release studies were carried out using USP type 1 apparatus in 900 ml of dissolution media. Release kinetics were analyzed using zero-order, Higuchi's square root and Ritger-Peppas' empirical equations. Release rate decreased with increase in polymer proportion and compression force. The release rate was lesser in formulations prepared using CP (20%) as compared to HPMC (20%) as compared to EC (20%). No significant difference was observed in the effect of pH of dissolution media on drug release from formulations prepared using HPMC or EC, but significant difference was observed in CP based formulations. Decrease in agitation speed from 100 to 50 rpm decreased release rate from HPMC and CP formulations but no significant difference was observed in EC formulations. Mechanism of release was found to be dependent predominantly on diffusion of drug through the matrix than polymer relaxation incase of HPMC and EC formulations, while polymer relaxation had a dominating influence on drug release than diffusion incase of CP formulations. Designed CR tablets with pH independent drug release characteristics and an initial release of 17-25% in first hour and extending the release up to 16-20 h, can overcome the disadvantages associated with conventional tablets of AZT.

  7. Antiviral activity and resistance profile of phosphazid--a novel prodrug of AZT.

    PubMed

    Machado, J; Salomon, H; Oliveira, M; Tsoukas, C; Krayevsky, A A; Wainberg, M A

    1999-01-01

    Both AZT and its novel 5'-hydrogen phosphonate derivative, Phosphazid, possess similar in vitro activity and resistance profiles. Experiments involving AZT-resistant virus isolates revealed a strong correlation between resistance to AZT and cross-resistance to Phosphazid. In vitro selection for resistance to Phosphazid yielded viruses that were about 15-fold less sensitive than wild-type virus to this drug. Sequencing of the reverse transcriptase region of seven Phosphazid-selected viruses revealed a single codon mutation, D67N, that is associated with resistance to AZT.

  8. Cost and cost-effectiveness of switching from d4T or AZT to a TDF-based first-line regimen in a resource-limited setting in rural Lesotho.

    PubMed

    Jouquet, Guillaume; Bygrave, Helen; Kranzer, Katharina; Ford, Nathan; Gadot, Laurent; Lee, Janice; Hilderbrand, Katherine; Goemaere, Eric; Vlahakis, Natalie; Trivino, Laura; Makakole, Lipontso; Cleary, Susan

    2011-11-01

    Latest World Health Organization guidelines recommend shifting away from Stavudine (d4T)-based regimens due to severe side effects. However, widespread replacement of d4T by Tenofovir (TDF) or Zidovudine (AZT) is hampered by cost concerns. We established the cost-effectiveness of alternative first-line regimens using primary utilization, cost, and outcome data from a program in a rural district in Lesotho. We calculated cost per patient-year, incremental costs, and incremental cost-effectiveness ratios per life year, and per Quality Adjusted Life Year gained. Uncertainty was assessed using multiway and probabilistic sensitivity analyses. Our study included 1260 patients representing 1635 patient-years on antiretroviral therapy (ART). Six hundred eight patients were on TDF, 290 were on AZT, and 362 were on d4T. Patients on d4T experienced more toxicities; toxicities with the biggest impact on quality of life were moderate neuropathy and severe lipodystrophy. The cost per patient-year ranged from US $266 on d4T to US $353 on TDF. Inpatient care and essential drug costs were higher for patients on d4T than on AZT or TDF. Incremental cost-effectiveness ratio results suggest that AZT-based ART is weakly dominated by a combination of d4T- and TDF-based ART. This is one of the first analyses to investigate the cost-effectiveness of TDF using primary data in a resource-poor setting. Although TDF-based first-line ART is more costly than d4T, it is also more effective. Political pressure should be exerted to encourage further price reductions and additional generic manufacturing for TDF and partner drugs such as Efavirenz. This should be met by a commitment from donors and implementers to ensure that supply is met by a clear demand.

  9. AZT-related mutation Lys70Arg in reverse transcriptase of human immunodeficiency virus type 1 confers decrease in susceptibility to ddATP in in vitro RT inhibition assay.

    PubMed

    Sharma, P L; Chatis, P A; Dogon, A L; Mayers, D L; McCutchan, F E; Page, C; Crumpacker, C S

    1996-09-15

    The genetic basis for didanosine (ddl) resistance in human immunodeficiency virus (HIV-1) has previously been shown to be commonly associated with a Leu to Val change at codon 74 in the HIV-1 RT gene. In this study sequential viral isolates were analyzed from five patients with prior zidovudine (AZT) use who received 6 to 16 months of ddl therapy. Following ddl therapy, viral isolates exhibited an increased AZT susceptibility and decreased ddl susceptibility. Sequence and nested PCR analysis of the HIV-1 RT gene revealed that two viral isolates contained the Leu to Val change at codon 74, and three other isolates with reduced susceptibility to ddl each contained changes at codons 65, 70, and 72. Site-directed mutagenesis was employed to insert specific mutations in RT gene of proviral clone pNL4-3. Analysis of virion-associated reverse transcriptase activity indicated that the Lys70Arg mutation resulted in an enzyme with 2- to 4-fold decreased susceptibility to ddATP. Statistical analysis of the inhibitory concentration for RT activity between pNL4-3 and mutant Lys70Arg viruses obtained in three independent RT inhibition assays was significant (P = 0.05) by student t test paired analysis. Drug susceptibility assays on the virus with Lys70Arg mutation showed a marginal decrease in susceptibility to ddl (1.5- to 2-fold) and about 4- to 6-fold decrease in susceptibility to AZT. Mutations Lys65Glu and Arg72Ser resulted in an impaired RT with greatly diminished functional RT activity. The AZT-associated Lys70Arg mutation results in an RT enzyme with decreased susceptibility to ddATP.

  10. Glaxo's AZT announcement welcomed, but detail is yet to follow. mother-to-child transmission.

    PubMed

    Worthington, H

    1998-04-01

    Following recently completed trials of AZT in Thailand among pregnant women which showed that a short course of AZT can significantly reduce the mother-to-child transmission of HIV, Glaxo Wellcome recently announced that it will supply the antiretroviral drug AZT at a preferential price for pregnant women infected with HIV in developing countries. Since the size of the HIV/AIDS epidemic and the quantity of AZT needed cannot be predicted, Glaxo Wellcome has stated that it is unfeasible to implement a mass donation program of the drug. The preferential public sector pricing was instead arrived at after 3 years of discussions and collaboration with UNAIDS, governments, and nongovernmental organizations (NGOs). Glaxo and UNAIDS both agree that the pricing will be a price reduction and not a subsidy, but additional details remain unclear. Eligible countries will be defined according to World Health Organization guidelines, with UNICEF likely to play a key role in the AZT's distribution.

  11. Retroviral integration: Site matters

    PubMed Central

    Demeulemeester, Jonas; De Rijck, Jan

    2015-01-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co‐opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine‐grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. PMID:26293289

  12. Kinetic modeling of the interactions between 4-methylumbelliferone, 1-naphthol, and zidovudine glucuronidation by udp-glucuronosyltransferase 2B7 (UGT2B7) provides evidence for multiple substrate binding and effector sites.

    PubMed

    Uchaipichat, Verawan; Galetin, Aleksandra; Houston, J Brian; Mackenzie, Peter I; Williams, J Andrew; Miners, John O

    2008-10-01

    Interactions between the UGT2B7-catalyzed glucuronidation of zidovudine (AZT), 4-methylumbelliferone (4MU), and 1-naphthol (1NP) were analyzed using multisite and empirical kinetic models to explore the existence of multiple substrate and effector binding sites within this important drug metabolizing enzyme. 4MU and 1NP glucuronidation by UGT2B7 exhibit sigmoidal kinetics characteristic of homotropic cooperativity (autoactivation), which may be modeled assuming the existence of two equivalent, interacting substrate binding sites. In contrast, UGT2B7-catalyzed AZT glucuronidation follows hyperbolic (Michaelis-Menten) kinetics. Although 4MU and 1NP decreased the binding affinity of AZT, the kinetics of AZT glucuronidation changed from hyperbolic to sigmoidal in the presence of both modifiers. Data were well described by a generic two-substrate binding site model in which there is no interaction between the sites in the absence of 4MU or 1NP, but heterotropic cooperativity results from the binding of modifier. Inhibition of 4MU and 1NP glucuronidation by AZT and interactions between 4MU and 1NP required more complex three-site models, where the modifier acts via a distinct effector site to alter either substrate binding affinity or Vmax without affecting the homotropic cooperativity characteristic of 4MU and 1NP glucuronidation. It is noteworthy that 1NP inhibited 4MU glucuronidation, whereas 4MU activated 1NP glucuronidation. The results are consistent with the existence of two "catalytic" sites for each substrate within the UGT2B7 active site, along with multiple effector sites. The multiplicity of binding and effector sites results in complex kinetic interactions between UGT2B7 substrates, which potentially complicates inhibition screening studies.

  13. Zidovudine as Modern Day Salvage Therapy for HIV Infection

    PubMed Central

    Johnson, James W.; Barroso, Luis F.; Wrenn, Rebekah H.; Williamson, John C.

    2014-01-01

    Abstract Resistance to the first-line NRTIs, tenofovir and emtricitabine, does not generally confer resistance to zidovudine. The objective of this study was to describe the efficacy of zidovudine as modern day salvage antiretroviral therapy. This was a single-center, retrospective, observational, cohort study. Adult HIV-positive patients prescribed a zidovudine-containing regimen between 2005 and 2010 were identified from a computer database. All patients had failed at least one prior antiretroviral regimen before zidovudine. The primary outcome measure was virologic success at 24 weeks. Other efficacy and safety outcomes were determined, including virologic success at 48 and 96 weeks, CD4 count change from baseline, and incidence of adverse effects. Sixty-nine subjects were enrolled. The mean age was 43 years, 70% were male, and 85.5% were black. Most patients were highly antiretroviral experienced. At 24 weeks, 63.8% and 72.5% of patients achieved HIV RNA less than 50 and 400 c/mL, respectively. The median change in CD4 count from baseline to week 24 was +70 cells/mm3. The percent of patients who discontinued zidovudine due to adverse effects was 10%. In this highly treatment-experienced population, zidovudine as part of a salvage regimen appeared effective. Gastrointestinal adverse effects were reported, but zidovudine-associated metabolic effects were uncommon, suggesting zidovudine was generally well tolerated. PMID:25365419

  14. Zidovudine as modern day salvage therapy for HIV infection.

    PubMed

    Kupiec, Katherine E; Johnson, James W; Barroso, Luis F; Wrenn, Rebekah H; Williamson, John C

    2014-11-01

    Resistance to the first-line NRTIs, tenofovir and emtricitabine, does not generally confer resistance to zidovudine. The objective of this study was to describe the efficacy of zidovudine as modern day salvage antiretroviral therapy. This was a single-center, retrospective, observational, cohort study. Adult HIV-positive patients prescribed a zidovudine-containing regimen between 2005 and 2010 were identified from a computer database. All patients had failed at least one prior antiretroviral regimen before zidovudine. The primary outcome measure was virologic success at 24 weeks. Other efficacy and safety outcomes were determined, including virologic success at 48 and 96 weeks, CD4 count change from baseline, and incidence of adverse effects. Sixty-nine subjects were enrolled. The mean age was 43 years, 70% were male, and 85.5% were black. Most patients were highly antiretroviral experienced. At 24 weeks, 63.8% and 72.5% of patients achieved HIV RNA less than 50 and 400 c/mL, respectively. The median change in CD4 count from baseline to week 24 was +70 cells/mm(3). The percent of patients who discontinued zidovudine due to adverse effects was 10%. In this highly treatment-experienced population, zidovudine as part of a salvage regimen appeared effective. Gastrointestinal adverse effects were reported, but zidovudine-associated metabolic effects were uncommon, suggesting zidovudine was generally well tolerated.

  15. AZT trials pose difficult breast-feeding dilemma.

    PubMed

    1998-02-01

    International AIDS experts and HIV infected women in Africa may soon face an impossible dilemma if short-term AZT treatment prevents perinatal transmission. HIV-infected mothers may not be able to afford infant formula or may not have access to safe water to mix with the formula, and may expose the child to HIV again through breast feeding. Few studies have addressed the breast feeding issue, although a controversial placebo-controlled study is underway in Nairobi. Pediatricians have promoted breast feeding as the preferred means to feed infants, and in many cases, mothers do not have other viable choices. Women who cannot afford formula may be forced to expose their children to HIV.

  16. Investigation of the Role of Breast Cancer Resistance Protein (Bcrp/Abcg2) on Pharmacokinetics and Central Nervous System Penetration of Abacavir and Zidovudine in the Mouse

    PubMed Central

    Giri, Nagdeep; Shaik, Naveed; Pan, Guoyu; Terasaki, Tetsuya; Mukai, Chisato; Kitagaki, Shinji; Miyakoshi, Naoki; Elmquist, William F.

    2016-01-01

    Many anti-human immunodeficiency virus 1 nucleoside reverse-transcriptase inhibitors have low central nervous system (CNS) distribution due in part to active efflux transport at the blood-brain barrier. We have previously shown that zidovudine (AZT) and abacavir (ABC) are in vitro substrates for the efflux transport protein breast cancer resistance protein (Bcrp) 1. We evaluated the influence of Bcrp1 on plasma pharmacokinetics and brain penetration of zidovudine and abacavir in wild-type and Bcrp1-deficient (Bcrp1−/−) FVB mice. There was no difference in either area under the concentration-time profiles for plasma (AUCplasma) or brain (AUCbrain) for zidovudine between the wild-type and Bcrp1−/− mice. The AUCplasma of abacavir was 20% lower in the Bcrp1−/− mice, whereas the AUCbrain was 20% greater. This difference resulted in a 1.5-fold increase in abacavir brain exposure in the Bcrp1−/− mice. The effect of selective and nonselective transport inhibitors on the ABC brain/plasma ratio at a single time point was evaluated. 3-(6-Isobutyl-9-methoxy-1,4-dioxo-1,2,3,4,6,7,12,12a-octahydropyrazino[1′,2′:1,6]pyrido[3,4-b]indol-3-yl)-propionicacid tert-butyl ester (Ko143), N[4[2-(6, 7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]phenyl]-5-methoxy-9-oxo-10H-acridine-4-carboxamide (GF120918), probenecid, and Pluronic P85 increased abacavir plasma concentrations in the wild-type mice. Abacavir plasma concentrations in Bcrp1−/− mice were increased by (R)-4-((1aR,6R,10bS)-1,2-difluoro-1,1a,6,10b-tetrahydrodibenzo(a,e)cyclopropa(c)cycloheptan-6-yl)-α-((5-quinoloyloxy)methyl)-1-piperazineethanol trihydrochloride (LY335979), GF120918, and probenecid, but not by Ko143. Brain/plasma concentration ratios in both the wild-type and Bcrp1−/− mice were increased by the P-glycoprotein inhibitors LY335979 and GF120918, but not by BCRP-selective inhibitors. These data indicate that deletion of Bcrp1 has little influence on the pharmacokinetics or brain

  17. SYNTHESIS, CHARACTERIZATION, AND IN VITRO ASSAY OF FOLIC ACID CONJUGATES OF 3′-AZIDO-3′-DEOXYTHYMIDINE (AZT): TOWARD TARGETED AZT BASED ANTICANCER THERAPEUTICS

    PubMed Central

    Vortherms, Anthony R.; Doyle, Robert P.; Gao, Dayuan; Debrah, Olivia; Sinko, Patrick J.

    2009-01-01

    Conjugates of three components namely folic acid, poly(ethylene glycol) and 3′-azido-3′-deoxythymidine (AZT) are presented. Folate-PEG units were coupled to AZT to facilitate delivery of the nucleoside into the cell. A convenient separation of the polydisperse PEGylated-folic acid regioisomers produced upon conjugation is described. This is to select for the active γ-regioisomer over the inactive α-regioisomer. In vitro cytotoxicity assays were conducted against an ovarian cell line (A2780/AD) that overexpresses the folate receptor (FR) and compared to a FR free control cell line. Compared to AZT a ~ 20-fold greater potency against the resistant ovarian line was observed for the conjugates. PMID:18205071

  18. The impact of sex and contraceptive therapy on the plasma and intracellular pharmacokinetics of zidovudine.

    PubMed

    Aweeka, Francesca T; Rosenkranz, Susan L; Segal, Yoninah; Coombs, Robert W; Bardeguez, Arlene; Thevanayagam, Lourdes; Lizak, Patricia; Aberg, Judith; Watts, D Heather

    2006-09-11

    Zidovudine remains part of combination antiretroviral therapy. Pharmacological studies rely on quantitation of active triphosphates in peripheral blood mononuclear cells. This study evaluated the impact of female sex and contraceptive therapy on zidovudine plasma and intracellular pharmacokinetics and the impact of contraceptive therapy on HIV viral load. Serial plasma and intracellular zidovudine pharmacokinetics following oral and intravenous dosing were determined in 18 men and 20 women treated with zidovudine. Women could repeat pharmacokinetics assessment following 2 months oral or injectable contraceptive therapy. Zidovudine plasma and intracellular mono-, di- and triphosphate concentrations were determined by liquid chromatography tandem mass spectrometry. Plasma and cervical viral loads were determined preceding and following 2 months of contraceptive therapy in women. Men exhibited higher area under the concentration versus time curve for intracellular zidovudine and zidovudine-monophosphate following oral and intravenous dosing and higher zidovudine triphosphate following oral dosing. There was no difference between men and women in plasma zidovudine parameters. Furthermore, contraceptive therapy had no effect on zidovudine plasma or intracellular pharmacokinetics or on plasma or cervical HIV-1 RNA levels. Using an optimized pharmacokinetic design, this study indicated men exhibit significantly higher zidovudine-monophosphate and zidovudine-triphosphate exposure following zidovudine oral administration, having implications for drug toxicity and overall tolerance of zidovudine therapy. The lack of an effect of contraceptive therapy on zidovudine pharmacokinetics is surprising in light of previous pharmacokinetic studies for drugs eliminated primarily through glucuronidation. Contraceptive therapy had no effect on plasma or cervical viral load, results consistent with previous findings.

  19. Biphotonic reactions of a dihydropyridine derivative of AZT related to AIDS dementia

    NASA Astrophysics Data System (ADS)

    Lindqvist, L.; Czochralska, B.; Kawczynski, W.

    1993-06-01

    It was shown that exposure of the AZT derivative 5'-(1,4-dihydro-1-methyl-3- pyridinyl-carbonyl)-3'-azido-2', 3'-dideoxythymidine) (H2PyrAZT) in aqueous solution to pulsed laser emission ((lambda) equals 355 nm, pulse length 2 ns) gives rise to photoelectron ejection by stepwise two-photon absorption. Absorption spectra of the semioxidized radicals obtained in this reaction were determined. It was shown that the photolysis did not affect the azido group.

  20. Targeting retroviral and lentiviral vectors.

    PubMed

    Sandrin, V; Russell, S J; Cosset, F L

    2003-01-01

    Retroviral vectors capable of efficient in vivo gene delivery to specific target cell types or to specific locations of disease pathology would greatly facilitate many gene therapy applications. The surface glycoproteins of membrane-enveloped viruses stand among the choice candidates to control the target cell receptor recognition and host range of retroviral vectors onto which they are incorporated. This can be achieved in many ways, such as the exchange of glycoprotein by pseudotyping, their biochemical modifications, their conjugation with virus-cell bridging agents or their structural modifications. Understanding the fundamental properties of the viral glycoproteins and the molecular mechanism of virus entry into cells has been instrumental in the functional alteration of their tropism. Here we briefly review the current state of our understanding of the structure and function of viral envelope glycoproteins and we discuss the emerging targeting strategies based on retroviral and lentiviral vector systems.

  1. Effect of L-menthol and 1,8-cineole on phase behavior and molecular organization of SC lipids and skin permeation of zidovudine.

    PubMed

    Narishetty, Sunil T K; Panchagnula, Ramesh

    2005-01-20

    The aim of this investigation was to study the effect of 1,8-cineole and L-menthol on phase behavior and molecular organization of Stratum corneum (SC) lipids and permeation of zidovudine (AZT) across human cadaver skin (HCS). Permeation studies were conducted across HCS using Franz diffusion cells at 37 degrees C. Differential scanning calorimetry (DSC) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were employed to understand the effect of terpenes on phase behavior and molecular organization of a model SC lipid system consisting of an equimolar mixture of ceramide, palmitic acid and cholesterol. Both 1,8-cineole and L-menthol applied at 5% w/v in 66.6% ethanol as a vehicle significantly enhanced the pseudosteady state flux of AZT across HCS. The vehicle reduced the number of endothermic transitions observed in the DSC thermogram of a hydrated model SC lipid system from three to two with a lowered midtransition temperature (Tm), while the inclusion of terpenes resulted in a single but very broad endothermic transition for the model SC lipid system. Correspondingly, ATR-FTIR studies revealed that both 1,8-cineole and L-menthol increased CH2 stretching frequencies on either side of lipid transition in addition to lowering the Tm of model SC lipid system by approximately 2-8 degrees C. The alterations observed in the amide-I frequencies of model SC lipid system after the inclusion of terpenes suggest that they disrupt the interlamellar hydrogen-bonding network at the polar head group region. Further, terpenes also increased the hydration levels of the lipid system probably by forming new aqueous channels. These results indicate that terpenes enhance transdermal permeation of AZT and other drugs by transforming SC lipids from a highly ordered orthorhombic perpendicular subcellular packing to a less ordered hexagonal subcell packing.

  2. ABSENCE OF CARDIAC TOXICITY OF ZIDOVUDINE IN INFANTS

    PubMed Central

    Lipshultz, Steven E.; Easley, Kirk A.; Orav, E. John; Kaplan, Samuel; Starc, Thomas J.; Bricker, J. Timothy; Lai, Wyman W.; Moodie, Douglas S.; Sopko, George; McIntosh, Kenneth; Colan, Steven D.

    2014-01-01

    Background Some evidence suggests that perinatal exposure to zidovudine may cause cardiac abnormalities in infants. We prospectively studied left ventricular structure and function in infants born to mothers infected with the human immunodeficiency virus (HIV) in order to determine whether there was evidence of zidovudine cardiac toxicity after perinatal exposure. Methods We followed a group of infants born to HIV-infected women from birth to five years of age with echocardiographic studies every four to six months. Serial echocardiograms were obtained for 382 infants without HIV infection (36 with zidovudine exposure) and 58 HIV-infected infants (12 with zidovudine exposure). Repeated-measures analysis was used to examine four measures of left ventricular structure and function during the first 14 months of life in relation to zidovudine exposure. Results Zidovudine exposure was not associated with significant abnormalities in mean left ventricular fractional shortening, end-diastolic dimension, contractility, or mass in either non–HIV-infected or HIV-infected infants. Among infants without HIV infection, the mean fractional shortening at 10 to 14 months was 38.1 percent for those never exposed to zidovudine and 39.0 percent for those exposed to zidovudine (mean difference, −0.9 percentage point; 95 percent confidence interval, −3.1 to 1.3 percentage points; P=0.43). Among HIV-infected infants, the mean fractional shortening at 10 to 14 months was similar in those never exposed to zidovudine (35.4 percent) and those exposed to the drug (35.3 percent) (mean difference, 0.1 percentage point; 95 percent confidence interval, −3.7 to 3.9 percentage points; P=0.95). Zidovudine exposure was not significantly related to depressed fractional shortening (shortening of 25 percent or less) during the first 14 months of life. No child over the age of 10 months had depressed fractional shortening. Conclusions Zidovudine was not associated with acute or chronic

  3. Retroviral superinfection resistance

    PubMed Central

    Nethe, Micha; Berkhout, Ben; van der Kuyl, Antoinette C

    2005-01-01

    The retroviral phenomenon of superinfection resistance (SIR) defines an interference mechanism that is established after primary infection, preventing the infected cell from being superinfected by a similar type of virus. This review describes our present understanding of the underlying mechanisms of SIR established by three characteristic retroviruses: Murine Leukaemia Virus (MuLV), Foamy Virus (FV), and Human Immunodeficiency Virus (HIV). In addition, SIR is discussed with respect to HIV superinfection of humans. MuLV resistant mice exhibit two genetic resistance traits related to SIR. The cellular Fv4 gene expresses an Env related protein that establishes resistance against MuLV infection. Another mouse gene (Fv1) mediates MuLV resistance by expression of a sequence that is distantly related to Gag and that blocks the viral infection after the reverse transcription step. FVs induce two distinct mechanisms of superinfection resistance. First, expression of the Env protein results in SIR, probably by occupancy of the cellular receptors for FV entry. Second, an increase in the concentration of the viral Bet (Between-env-and-LTR-1-and-2) protein reduces proviral FV gene expression by inhibition of the transcriptional activator protein Tas (Transactivator of spumaviruses). In contrast to SIR in FV and MuLV infection, the underlying mechanism of SIR in HIV-infected cells is poorly understood. CD4 receptor down-modulation, a major characteristic of HIV-infected cells, has been proposed to be the main mechanism of SIR against HIV, but data have been contradictory. Several recent studies report the occurrence of HIV superinfection in humans; an event associated with the generation of recombinant HIV strains and possibly with increased disease progression. The role of SIR in protecting patients from HIV superinfection has not been studied so far. The phenomenon of SIR may also be important in the protection of primates that are vaccinated with live attenuated simian

  4. Retroviral infections of small animals.

    PubMed

    Dunham, Stephen P; Graham, Elizabeth

    2008-07-01

    Retroviral infections are particularly important in cats, which are commonly infected with feline leukemia virus and feline immunodeficiency virus. This article describes the biology of these viruses and explores current issues regarding vaccination and diagnosis. The seeming lack of a recognized retrovirus infection in dogs is speculated on, and current and potential future therapies are discussed.

  5. Effects of thymidine and uridine on the phosphorylation of 3'-azido-3'-deoxythymidine (zidovudine) in human mononuclear cells

    SciTech Connect

    Szebeni, J.; Patel, S.S.; Hung, K.; Wahl, L.M.; Weinstein, J.N. )

    1991-01-01

    The effects of thymidine and uridine on the phosphorylation of 3'-azido-3'-deoxythymidine (AZT) were studied in various human mononuclear cell preparations. Thymidine suppressed ({sup 3}H)AZT phosphorylation in the same concentration range (20 to 100 microM) in which it antagonizes the anti-human immunodeficiency virus activity of AZT. Uridine, in turn, had no influence on AZT phosphorylation, just as it has no effect on the anti-human immunodeficiency virus activity of AZT. These findings are consistent with a close relationship between the inhibition of AZT phosphorylation and the influence of physiological nucleosides on the antiviral activity of AZT.

  6. Thiazolobenzimidazole: biological and biochemical anti-retroviral activity of a new nonnucleoside reverse transcriptase inhibitor.

    PubMed

    Buckheit, R W; Hollingshead, M G; Germany-Decker, J; White, E L; McMahon, J B; Allen, L B; Ross, L J; Decker, W D; Westbrook, L; Shannon, W M

    1993-07-01

    Thiazolobenzimidazole (NSC 625487) was a highly potent inhibitor of human immunodeficiency virus-induced cell killing and viral replication in a variety of human cell lines, as well as fresh human peripheral blood lymphocytes and macrophages. The compound was active against a panel of biologically diverse laboratory and clinical strains of HIV-1, including the AZT-resistant strain G910-6. However, the agent was inactive against HIV-2 and a pyridinone-resistant strain (A17) of HIV-1, a strain which is cross-resistant to several structurally diverse members of a common pharmacologic class of nonnucleoside reverse transcriptase inhibitors. The compound selectively inhibited HIV-1 reverse transcriptase but not HIV-2 reverse transcriptase. Combinations of thiazolobenzimidazole with either AZT or ddI synergistically inhibited HIV-1 induced cell killing in vitro. Thiazolobenzimidazole also inhibited the replication of the Rauscher murine leukemia retrovirus. Thus, thiazolobenzimidazole is a new active anti-HIV-1 chemotype and may represent a subclass of nonnucleoside reverse transcriptase inhibitors with an enhanced range of anti-retroviral activity.

  7. Determination of liposome permeability of ionizable carbamates of zidovudine by steady state fluorescence spectroscopy.

    PubMed

    Raviolo, Mónica A; Sanchez, Julieta M; Briñón, Margarita C; Perillo, María A

    2008-02-15

    In the present paper the relative permeabilities of AZT-Pyp and AZT-Ethy across a phospholipid bilayer were estimated by the means of fluorescence spectroscopy. The center of spectral mass of both non-encapsulated AZT-derivatives (AZT-der) emission spectra increased as a function of the illumination time inside the spectrofluorimeter cell. This phenomenon was even more evident when drugs were incubated under an UV mercury lamp, suggesting its photolytic origin. AZT-der were protected from photolysis inside liposomes and decomposed upon irradiation when they were free in the aqueous phase. The time-dependent decrease in the fluorescence intensity at a constant wavelength was fitted to a two-exponential equation and the values of rate constants for permeability and photolysis were calculated. It was concluded that AZT-Pyp but not AZT-Ethy diffused across the bilayer. This behavior correlated with the molecular volumes of AZT-Pyp (379.6A(3)) and AZT-Ethy (450.5A(3)), determined from the minimum energy conformations but not with previously reported logP values. These results reinforce the concept that not only lipophilicity but also membrane structure and AZT-der molecular size had a critical influence in passive diffusion across bilayers and may help in future refinements of other AZT-der molecular design.

  8. Zidovudine Adherence in Persons with AIDS

    PubMed Central

    Smith, Meredith Y; Rapkin, Bruce D; Morrison, Anne; Kammerman, Sandra

    1997-01-01

    OBJECTIVE To examine the relation of patient beliefs about medication usage and adherence to zidovudine (ZDV) therapy in persons with AIDS. DESIGN Face-to-face interviews were used to determine attitudes of persons with AIDS toward ZDV and other prescribed medications, history of ZDV usage, and sociodemographics. SETTING A public hospital infectious disease clinic, an AIDS day care program, and an inpatient unit in a voluntary hospital where care was provided cooperatively by staff and an informal–care partner. PATIENTS/PARTICIPANTS One hundred forty-one people with the acquired immunodeficiency syndrome agreed to be reinterviewed as part of a longitudinal, New York City–based study examining outcomes related to quality of life. Initial recruitment procedures were to approach all active AIDS patients at each of the three sites between January and July of 1992; reinterviews, which were conducted an average of 6 months later, occurred from mid-1992 through May of 1993. MEASUREMENTS AND MAIN RESULTS The Zidovudine Drug Attitude Inventory was used to assess subjective feelings and attitudes concerning ZDV and prescribed medications in general. Respondents were grouped into five categories on the basis of their ZDV usage history: (1) “short-term” users (i.e., those who had been taking ZDV for 25 months or less); (2) “long-term” users (i.e., those who had been taking ZDV for more than 25 months); (3) self-terminated users; (4) doctor-terminated users; and (5) never users. Long-term users were likely to view ZDV as an illness prophylactic. In contrast, self-terminated users and never users were most likely to believe that ZDV caused adverse side effects and that medicine need not be taken as prescribed. CONCLUSIONS Patients’ beliefs about ZDV were significantly associated with adherence-related behavior. In particular, those who had self-terminated ZDV treatment believed that taking the drug was harmful, were skeptical of its ability to prevent illness, and

  9. Zidovudine and Lamivudine for HIV Infection.

    PubMed

    Anderson, Peter L; Rower, Joseph E

    2010-01-01

    Zidovudine and lamivudine (ZDV and 3TC) are long-standing nucleoside analog-reverse transcriptase inhibitors (NRTIs) with extensive clinical experience in a wide spectrum of patients from in utero through childhood and adult ages. The safety profiles of both drugs are well-known and side effects for ZDV most commonly include nausea/vomiting, fatigue, anemia/neutopenia, and lipoatrophy; while 3TC is well-tolerated. ZDV-3TC is currently a viable alternative NRTI backbone for initial three-drug therapy of HIV infection when tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) cannot be used because of a relative or absolute contraindication. ZDV-3TC continue to be viable alternatives for children, pregnant women and in resource limited settings where other recommended options are not readily available. ZDV-3TC penetrate the Central Nervous System (CNS) well, which makes ZDV-3TC attractive for use in patients with HIV-associated neurological deficits. Additional benefits of these drugs may include the use of ZDV in combination with certain NRTIs to exert selective pressure to prevent particular drug resistance mutations from developing, and giving a short course of ZDV-3TC to prevent resistance after prophylactic single dose nevirapine.

  10. RETROVIRAL INTEGRASE: THEN AND NOW

    PubMed Central

    Andrake, Mark D.; Skalka, Anna Marie

    2016-01-01

    The retroviral integrases are virally encoded, specialized recombinases that catalyze the insertion of viral DNA into the host cell’s DNA, a process that is essential for virus propagation. We have learned a great deal since the existence of an integrated form of retroviral DNA (the provirus) was first proposed by Howard Temin in 1964. Initial studies focused on the genetics and biochemistry of avian and murine virus DNA integration, but the pace of discovery increased substantially with advances in technology, and an influx of investigators focused on the human immunodeficiency virus (HIV). We begin with a brief account of the scientific landscape in which some of the earliest discoveries were made, and summarize research that led to our current understanding of the biochemistry of integration. A more detailed account of recent analyses of integrase structure follows, as they have provided valuable insights into enzyme function and raised important new questions. PMID:26958915

  11. Extensive retroviral diversity in shark.

    PubMed

    Han, Guan-Zhu

    2015-04-28

    Retroviruses infect a wide range of vertebrates. However, little is known about the diversity of retroviruses in basal vertebrates. Endogenous retrovirus (ERV) provides a valuable resource to study the ecology and evolution of retrovirus. I performed a genome-scale screening for ERVs in the elephant shark (Callorhinchus milii) and identified three complete or nearly complete ERVs and many short ERV fragments. I designate these retroviral elements "C. milli ERVs" (CmiERVs). Phylogenetic analysis shows that the CmiERVs form three distinct lineages. The genome invasions by these retroviruses are estimated to take place more than 50 million years ago. My results reveal the extensive retroviral diversity in the elephant shark. Diverse retroviruses appear to have been associated with cartilaginous fishes for millions of years. These findings have important implications in understanding the diversity and evolution of retroviruses.

  12. Tropical spastic paraparesis treated with Combivir (lamivudine-zidovudine).

    PubMed

    Hassan, Syed; Amer, Syed; Zervos, Marcus

    2013-05-01

    Tropical spastic paraparesis (TSP) or human T-cell leukemia virus-type 1 (HTLV-I)-associated myelopathy is caused by human T-lymphotropic virus type 1. It is a slow, progressive spastic paraparesis with significant morbidity and causing profound repercussions on quality of life. No therapies have been found to persistently improve the outcome in these patients. We present a patient with HTLV-1-associated myelopathy/TSP (HAM/TSP) who was treated with Combivir (lamivudine-zidovudine, GlaxoSmithKline, London, UK). She was walker-dependent for several years but, soon after treatment with lamivudine-zidovudine, was able to walk using only a cane. The role of lamivudine-zidovudine should be investigated further in this patient population. Published by Elsevier Ltd.

  13. Effect of AZT on thymidine phosphorylation in cultured H9c2, U-937, and Raji cell lines

    PubMed Central

    Lynx, Matthew D.; Kang, Bae-Kwang; McKee, Edward E.

    2008-01-01

    3′-azido-3′-deoxythymidine (AZT) has been shown to be a potent inhibitor of thymidine kinase 2 in work from this laboratory. Inhibition results in decreased salvage of thymidine to TTP, which may lead to depletion of the TTP pool and result in the mitochondrial dysfunction and mt-DNA depletion observed with AZT toxicity. The effect of AZT on thymidine phosphorylation in growing cells expressing thymidine kinase 1 has not been shown. Three cell lines were used in these experiments: H9c2, derived from rat cardiomyoblasts; U-937, derived from human monocytes; and Raji, derived from human lymphoblasts. AZT inhibited growth in a concentration dependent manner in U-937 cells, but not the other cell lines. The phosphorylation of [3H]-thymidine or [3H]-AZT was determined during log growth. All cell lines salvaged and phosphorylated thymidine to TTP, with TTP the major product. The U-937 cells had a much more active salvage pathway than the other cells. All cell lines phosphorylated AZT to the triphosphate, but the major product was AZTMP. The AZT inhibition of growth of the U-937 cells did not correlate with levels of phosphorylated AZT. In contrast, pro-drug AZT was shown to inhibit thymidine phosphorylation in all lines with 50% inhibition concentrations (IC50) ranging from 4.4–21.9 μM. Since the U-937 cells expressed higher activity of the salvage pathway than the other cell lines, the U-937 cells may rely more heavily on the salvage pathway for TTP synthesis, accounting for AZT inhibition of growth. PMID:18295188

  14. The selective in vitro cytotoxicity of carcinoma cells by AZT is enhanced by concurrent treatment with delocalized lipophilic cations.

    PubMed

    Modica-Napolitano, Josephine S; Nalbandian, Raffi; Kidd, Marianne E; Nalbandian, Angele; Nguyen, Chilinh C

    2003-07-30

    This study assessed the selective growth inhibitory effect on cultured carcinoma cells by 3'-azido-3'-deoxythymidine (AZT), as a single agent, and in combination with delocalized lipophilic cations (DLCs) that are known to inhibit mitochondrial function. In cytotoxicity assays, treatment of cells with varying concentrations of AZT induced a dose-dependent inhibition of cell growth of the human carcinoma lines DU-145 (prostate; IC50 at 24 microM), MCF-7 (breast; IC50 at 22 microM), and CX-1 (colon; IC50 at 23 microM), yet caused no significant effect on the growth of the control epithelial cell line CV-1 (monkey kidney) at a concentration as high as 50 microM AZT. Combination treatment employing a constant concentration (1.25 microM) of the DLC dequalinium chloride (DECA) plus varying concentrations of AZT (0-50 microM) enhanced the AZT-induced cytotoxicity of carcinoma cells at least fourfold for MCF-7 and CX-1 cells (IC50 at 5 microM AZT), and twofold for DU-145 cells (IC50 at 11 microM AZT). Similar results were obtained in DU-145 cells using a constant concentration of the DLC MKT-077 (1.0 microM) and varying concentrations of AZT (IC50 at 12.5 microM). As expected, the drug combination of constant DLC and varying AZT had no significant effect on the growth of CV-1 cells. Clonogenic assays demonstrated up to 20-fold enhancement of selective carcinoma cell killing by combination vs. single agent treatment, depending on the specific drug combination and concentrations used. It is hypothesized that the efficacy of the AZT/DLC drug combination in carcinoma cell killing may be based on a dual selectivity involving inhibition of mitochondrial energy metabolism and inhibition of DNA synthesis due to limited deoxythymidine monophosphate availability.

  15. [Effect of highly active anti-retroviral therapy on prevention of mother to child transmission of HIV and on infant growth and development].

    PubMed

    He, Yan; Luo, Yan; Ding, Yi-ling; Zheng, Yu-huang; Li, Jing; Huang, Jian; Li, Jie-min

    2011-10-01

    To identify the effect of highly active anti-retroviral therapy (HAART) on prevention of mother to child transmission (PMTCT) of HIV and on infant growth and development. A total of 16 HIV-infected women or pregnant women selected in this study received HAART before or 18 - 24 weeks after pregnancy. The treatment included taking Zidovudine (AZT) 0.3 g each time, twice a day, Lamivudine (3TC) 0.3 g each time, once a day and Nevirapine (NVP) 0.2 g each time, twice a day or Efavirenz (EFV) 0.6 g each time, once a day, as well as labor intervention and artificial feeding. The growth index for 17 infants from HIV-infected mothers (experimental group) and 16 normal infants (control group) were observed for 18 months. Neonatal hemoglobin (Hb), liver and kidney function, serum iron and calcium were detected at neonatal period and at 12(th) month, respectively. All the pregnant women were in good conditions and had tolerance with HAART. The birth weight, length and Apgar score of the newborns in the experimental group were (3.5 ± 0.9) kg, (54.2 ± 3.8) cm and 7 - 10 scores respectively, however those in the control group were (3.6 ± 0.8) kg, (55.6 ± 3.6) cm and 8 - 10 scores (t(weight) = 1.01, t(length) = 6.98, P > 0.05). Weight and length of infants in experimental group were (9.36 ± 1.8) kg and (76.3 ± 2.7) cm at 12(th) month, while those in control group were (9.86 ± 2.5) kg and (76.8 ± 2.9) cm (t(weight) = 0.83, t(length) = 1.00, P > 0.05). The level of Hb in experimental group was (126.2 ± 16.7) g/L, and was (148.6 ± 20.5) g/L in control group (t = -5.89, P = 0.11). At 12(th) month, the levels of Hb and the total bilirubin (TB) were (125.9 ± 19.8) g/L and (11.7 ± 3.5) µmol/L in experimental group; and those in the control group were (130.1 ± 18.7) g/L and (13.2 ± 3.7) µmol/L (t(Hb) = -3.82, t(TB) = -2.14, P > 0.05). Serum iron and calcium were (25.4 ± 5.7) µmol/L and (26.4 ± 7.2) µmol/L at neonatal period and were (2.3 ± 0.6) mol/L and (2.8 ± 0

  16. A comparison of maternal anemia between HIV infected pregnant women receiving zidovudine-based and zidovudine-free highly active Antiretroviral therapy (HAART).

    PubMed

    Lertcheewakarn, Pattaramas; Tongprasert, Fuanglada

    2014-04-01

    To compare the prevalence of maternal anemia associated with usage of Zidovudine-free and Zidovudine-based HAART during pregnancy. A retrospective cohort study was conducted in HIV-infected pregnant women receiving HAART between January 2006 and December 2012 in Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand. Changes in hemoglobin levels were compared between zidovudine-free and zidovudine-based HAARTgroups. Sixty-six pregnant women who received HAART pre-exposure hemoglobin levels showed no significant difference between the zidovudine-free (14 cases) and the zidovudine-based (52 cases) groups. In non-anemic pregnant women before HAART initiation, the prevalence of post-exposure anemia was 40.5%, and similar in both groups. Post-exposure, decreased hemoglobin levels were greater in the zidovudine-based group (-1.46 +/- 0.64 g/dL) than the zidovudine-free group (-1.29 +/- 1.26 g/dL), but the difference was not significant (p = 0.766). Duration of the lowest post-exposure hemoglobin levels was shorter in the zidovudine-based group than the zidovudine-free group, but the difference was not significant (71.5 days and 105.6 days, p = 0.123). In almost half of the cases, both zidovudine-based and zidovudine-free HAART exposure was associated with substantial risk of maternal anemia during pregnancy. Pregnant women receiving HAART regimens may be at significant risk of anemia two to three months after exposure and should be adequately monitored for this complication.

  17. A model for the immune system response to HIV: AZT treatment studies

    SciTech Connect

    Kirschner, D.E. . Dept. of Mathematics); Perelson, A.S. )

    1993-01-01

    We use mathematical models to describe the interaction of the immune system with the human immunodeficiency virus (HIV). Our model includes T-lymphocytes and macrophages, cells which can be infected with the virus. Using our model we compare the efficacy of AZT treatments given at different stages of disease progression in order to predict when treatment should be initiated.

  18. A model for the immune system response to HIV: AZT treatment studies

    SciTech Connect

    Kirschner, D.E.; Perelson, A.S.

    1993-05-01

    We use mathematical models to describe the interaction of the immune system with the human immunodeficiency virus (HIV). Our model includes T-lymphocytes and macrophages, cells which can be infected with the virus. Using our model we compare the efficacy of AZT treatments given at different stages of disease progression in order to predict when treatment should be initiated.

  19. Retroviral Oncogenes: A Historical Primer

    PubMed Central

    Vogt, Peter K.

    2012-01-01

    Retroviruses are the original source of oncogenes. The discovery and characterization of these genes were made possible by the introduction of quantitative cell biological and molecular techniques for the study of tumor viruses. Key features of all retroviral oncogenes were first identified in src, the oncogene of Rous sarcoma virus. These include non-involvement in viral replication, coding for a single protein, and cellular origin. The myc, ras and erbB oncogenes quickly followed src, and these together with pi3k are now recognized as critical driving forces in human cancer. PMID:22898541

  20. Continuum Theory of Retroviral Capsids

    NASA Astrophysics Data System (ADS)

    Nguyen, T. T.; Bruinsma, R. F.; Gelbart, W. M.

    2006-02-01

    We present a self-assembly phase diagram for the shape of retroviral capsids, based on continuum elasticity theory. The spontaneous curvature of the capsid proteins drives a weakly first-order transition from spherical to spherocylindrical shapes. The conical capsid shape which characterizes the HIV-1 retrovirus is never stable under unconstrained energy minimization. Only under conditions of fixed volume and/or fixed spanning length can the conical shape be a minimum energy structure. Our results indicate that, unlike the capsids of small viruses, retrovirus capsids are not uniquely determined by the molecular structure of the constituent proteins but depend in an essential way on physical constraints present during assembly.

  1. Protective cellular retroviral immunity requires both CD4+ and CD8+ immune T cells.

    PubMed Central

    Hom, R C; Finberg, R W; Mullaney, S; Ruprecht, R M

    1991-01-01

    We have found previously that postexposure chemoprophylaxis with 3'-azido-3'-deoxythymidine (also known as zidovudine or AZT) in combination with recombinant human alpha A/D interferon fully protected mice exposed to a lethal dose of Rauscher murine leukemia virus (RLV) against viremia and disease. After cessation of therapy, over 90% of these mice were able to resist rechallenge with live RLV, thus demonstrating an acquired immunity. Adoptive cell transfer of 4 x 10(7) cells from immunized mice fully protected naive recipients from viremia and splenomegaly after RLV challenge. However, when these immune T cells were fractionated into CD4+ and CD8+ subpopulations, only partial protection was found when 4 x 10(7) T cells of either subset were given. Full protection against RLV challenge was seen again when the T-cell subsets from immunized mice were recombined and transferred at the same number into naive mice. We conclude that cellular immunity alone is protective and that both CD4+ and CD8+ cell types are required for conferring full protection against live virus challenge. Images PMID:1898666

  2. Induction of zidovudine glucuronidation and amination pathways by rifampicin in HIV-infected patients

    PubMed Central

    Gallicano, Keith D; Sahai, Jan; Shukla, Vijay K; Seguin, Isabelle; Pakuts, Attila; Kwok, David; Foster, Brian C; Cameron, D William

    1999-01-01

    Aims The objective of the study was to determine the effect of multiple doses of rifampicin on the steady-state pharmacokinetics of zidovudine and its 5′-glucuronosyl (GZDV) and 3′-amino (AMT) metabolites. Methods Eight asymptomatic HIV-infected patients (seven male, one female) participated in this three-period longitudinal study. Each patient received zidovudine (200 mg every 8 h) for 14 days (period 1), followed by rifampicin (600 mg every 24 h) with zidovudine for 14 days (period 2), and then zidovudine alone for a further 14 days (period 3). Blood and urine samples were collected over 6 h on the last day of each period for measurements of zidovudine and GZDV by h.p.l.c.-u.v. and AMT by h.p.l.c.-m.s-m.s. Results Compared with zidovudine-alone values in period 1, 14 days of coadministration with rifampicin significantly increased zidovudine oral clearance (89%) and formation clearances to GZDV (100%) and AMT (82%). Correspondingly, there were decreases in maximum plasma concentration (43%), AUC (47%) and urine recovery (37%) of zidovudine. GZDV/zidovudine and AMT/zidovudine AUC ratios increased by 99% and 36%, respectively, despite a significant 29% decrease in AMT AUC. After stopping rifampicin for 14 days, values of these pharmacokinetic parameters returned to within 26% of baseline. Over the three periods AMT plasma levels were < 18 ng ml−1 (n = 6) and < 40 ng ml−1 (n = 2), and molar AMT/zidovudine AUC ratios ranged from 1.7% to 4.5%. Conclusions Rifampicin induced zidovudine glucuronidation and amination pathways resulting in decreased plasma and urine exposures to zidovudine. AMT plasma exposure decreased because induction was more pronounced for the major GZDV metabolite. The magnitude of the residual inductive effect was minimal at 14 days after stopping rifampicin. PMID:10417493

  3. Efficient syntheses of [¹¹C]zidovudine and its analogs by convenient one-pot palladium(0)-copper(I) co-mediated rapid C-[¹¹C]methylation.

    PubMed

    Zhang, Zhouen; Doi, Hisashi; Koyama, Hiroko; Watanabe, Yasuyoshi; Suzuki, Masaaki

    2014-06-30

    The nucleosides zidovudine (AZT), stavudine (d4T), and telbivudine (LdT) are approved for use in the treatment of human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. To promote positron emission tomography (PET) imaging studies on their pharmacokinetics, pharmacodynamics, and applications in cancer diagnosis, a convenient one-pot method for Pd(0)-Cu(I) co-mediated rapid C-C coupling of [(11)C]methyl iodide with stannyl precursor was successfully established and applied to synthesize the PET tracers [(11)C]zidovudine, [(11)C]stavudine, and [(11)C]telbivudine. After HPLC purification and radiopharmaceutical formulation, the desired PET tracers were obtained with high radioactivity (6.4-7.0 GBq) and specific radioactivity (74-147 GBq/µmol) and with high chemical (>99%) and radiochemical (>99.5%) purities. This one-pot Pd(0)-Cu(I) co-mediated rapid C-[(11)C]methylation also worked well for syntheses of [methyl-(11)C]thymidine and [methyl-(11)C]4'-thiothymidine, resulting twice the radioactivity of those prepared by a previous two-pot method. The mechanism of one-pot Pd(0)-Cu(I) co-mediated rapid C-[(11)C]methylation was also discussed.

  4. Non-Retroviral Fossils in Vertebrate Genomes

    PubMed Central

    Horie, Masayuki; Tomonaga, Keizo

    2011-01-01

    Although no physical fossils of viruses have been found, retroviruses are known to leave their molecular fossils in the genomes of their hosts, the so-called endogenous retroviral elements. These have provided us with important information about retroviruses in the past and their co-evolution with their hosts. On the other hand, because non-retroviral viruses were considered not to leave such fossils, even the existence of prehistoric non-retroviral viruses has been enigmatic. Recently, we discovered that elements derived from ancient bornaviruses, non-segmented, negative strand RNA viruses, are found in the genomes of several mammalian species, including humans. In addition, at approximately the same time, several endogenous elements of RNA viruses, DNA viruses and reverse-transcribing DNA viruses have been independently reported, which revealed that non-retroviral viruses have played significant roles in the evolution of their hosts and provided novel insights into virology and cell biology. Here we review non-retroviral virus-like elements in vertebrate genomes, non-retroviral integration and the knowledge obtained from these endogenous non-retroviral virus-like elements. PMID:22069518

  5. Zidovudine, trimethoprim, and dapsone pharmacokinetic interactions in patients with human immunodeficiency virus infection.

    PubMed Central

    Lee, B L; Safrin, S; Makrides, V; Gambertoglio, J G

    1996-01-01

    Zidovudine is widely prescribed for the treatment of human immunodeficiency virus (HIV) infection. Trimethoprim and dapsone are commonly used in the management of Pneumocystis carinii pneumonia in HIV-infected patients. To examine the pharmacokinetic interactions among these drugs, eight HIV-infected patients (26 to 43 years old) with a mean CD4 count of 524.4 +/- 405.7 cells per mm3 received zidovudine (200 mg), trimethoprim (200 mg), and dapsone (100 mg) as single agents and in two- and three-drug combinations. Blood and urine samples were collected at a specified time and analyzed for zidovudine, zidovudine-glucuronide, trimethoprim, dapsone, and monoacetyl-dapsone concentrations under single-dose and steady-state conditions. Zidovudine did not influence the pharmacokinetic disposition of dapsone or trimethoprim. Dapsone had no effect on the pharmacokinetic disposition of zidovudine. Trimethoprim significantly decreased the renal clearance of zidovudine by 58% (5.0 +/- 1.8 versus 2.1 +/- 0.5 ml/min/kg of body weight [P < 0.05]). There was a concurrent 54% decrease in the mean urinary recovery of zidovudine (11.7 +/- 3.5 versus 5.4 +/- 3.0 [P < 0.05]), and the metabolic ratio was decreased by 78% (0.32 +/- 0.4 versus 0.07 +/- 0.05 [P < 0.05]). The mean area under the concentration-time curve from 0 to 6 h of the zidovudine-glucuronide/ zidovudine ratio was unchanged. We conclude that zidovudine, trimethoprim, and dapsone can be coadministered to patients with AIDS without significant pharmacokinetic interaction. However, in AIDS patients with liver impairment and impaired glucuronidation, doses of zidovudine may need to be decreased. PMID:8723472

  6. Evidence that high-dosage zidovudine at time of retrovirus exposure reduces antiviral efficacy.

    PubMed Central

    Mathes, L E; Hayes, K A; Kociba, G

    1996-01-01

    The antiviral efficacy of prophylactic 3'-azido-3'-deoxythymidine (AZT) therapy administered by continuous infusion or intermittent injection was compared in pediatric cats infected with feline leukemia virus. A 4-week treatment regimen of AZT was initiated at -48, 8, or 96 h postinfection (p.i.). For AZT therapy begun at -48 h p.i., significant efficacy was attained when therapy was given by continuous infusion but not by intermittent injection. However, when AZT therapy was delayed until 96 h p.i., both continuous infusion and intermittent injection gave complete protection. The results suggest that intermittent AZT administration is less efficacious than continuous infusion. Higher peak AZT concentrations in plasma associated with intermittent injection compared with those associated with continuous infusion may be immunotoxic, thus reducing the drug-induced vaccine effect. Furthermore, AZT toxicity seemed to be restricted to a window of sensitivity close to the time of virus challenge because delaying the start of AZT therapy until 96 h p.i. was highly efficacious, regardless of the method of administration. PMID:8878603

  7. Altered bleeding time associated with ibuprofen and zidovudine use.

    PubMed

    Pieper, B; Smitherman, H C

    1998-05-01

    The purpose of this article is to describe a patient who was HIV-positive, had a massive venous ulcer, and developed a prolonged bleeding time with marked blood loss from the ulcer. The patient underwent a workup to rule out possible causes for this prolonged bleeding time; all studies were negative. A review of his history identified that he was self-medicating with ibuprofen while taking zidovudine. A potentiated effect of these two medications on the bleeding time has been reported in the literature. This case illustrates the importance of revisiting a patient's history while working up an acute problem as well as clinically monitoring for blood loss if a person takes ibuprofen and zidovudine.

  8. Pharmacokinetics of saquinavir, zidovudine, and zalcitabine in combination therapy.

    PubMed Central

    Vanhove, G F; Kastrissios, H; Gries, J M; Verotta, D; Park, K; Collier, A C; Squires, K; Sheiner, L B; Blaschke, T F

    1997-01-01

    We investigated the pharmacokinetics of zidovudine, zalcitabine, and saquinavir in AIDS Clinical Trial Group protocol 229. Patients received either saquinavir, zalcitabine, or a combination of both, together with zidovudine three times a day. Approximately 100 patients were enrolled in each treatment arm, and intensive pharmacokinetic studies were performed on about 25 patients per arm at weeks 1 and 12. We estimated the pharmacokinetic parameters of all three drugs by using parametric and nonparametric methods. The mean values of the pharmacokinetic parameters of zidovudine (clearance [CL]/bioavailability [F], 168 liters/h; volume of distribution [V]/F, 185 liters; half-life, 0.76 h) and zalcitabine (CL/F, 25 liters/h; V/F, 92.2 liters; half-life, 2.7 h) were similar to those reported previously. For saquinavir, the mean pharmacokinetic parameter estimates using parametric methods were as follows: maximum concentration of drug in serum [Cmax], 70.8 ng/ml; time to Cmax, 3.11 h; area under the curve, 809 ng x h/ml; CL/F, 989 liters/h; V/F, 1,503 liters; half-life, 1.38 h. For all three drugs, clearance decreased with age. Weight did not influence the clearance of zidovudine, but the clearance of zalcitabine and saquinavir increased with weight. There were no differences in pharmacokinetic parameters between study weeks and arms, suggesting that there is no change in kinetics with chronic administration and that there are no significant pharmacokinetic interactions among these three drugs. PMID:9371345

  9. Quantitative relationships between zidovudine exposure and efficacy and toxicity.

    PubMed Central

    Drusano, G L; Balis, F M; Gitterman, S R; Pizzo, P A

    1994-01-01

    We examined the relationship between the concentrations of zidovudine in plasma given by continuous intravenous infusion to human immunodeficiency virus-positive pediatric patients and a surrogate marker of outcome (measured by the increase in the number of CD4-positive T cells) as well as drug-mediated toxicity (change in granulocyte count). The return of CD4-positive T cells was most strongly related to the number of these cells present at the start of therapy. Drug concentration data added little explanatory power to this relationship, indicating that the effect of zidovudine was near maximal throughout the range of concentrations examined. The change in granulocyte count was significantly correlated with zidovudine concentration both from weeks 1 through 8 and from weeks 8 through 12. These findings imply that it may be wise to stratify phase I antiretrovirus drug trials for the entry level of CD4-positive T cells if pharmacodynamic relationships with this marker as the dependent variable are to be sought. Continued efforts need to be made to derive quantitative relationships between drug exposure and measures of both efficacy and toxicity so that the maximal amount of information is derived from small phase I studies. PMID:7986002

  10. Helminthic Infections Rates and Malaria in HIV-Infected Pregnant Women on Anti-Retroviral Therapy in Rwanda

    PubMed Central

    Ivan, Emil; Crowther, Nigel J.; Mutimura, Eugene; Osuwat, Lawrence Obado; Janssen, Saskia; Grobusch, Martin P.

    2013-01-01

    Background Within sub-Saharan Africa, helminth and malaria infections cause considerable morbidity in HIV-positive pregnant women and their offspring. Helminth infections are also associated with a higher risk of mother-to-child HIV transmission. The aim of this study was to determine the prevalence of, and the protective and risk factors for helminth and malaria infections in pregnant HIV-positive Rwandan women receiving anti-retroviral therapy (ART). Methodology and principle findings Pregnant females (n = 980) were recruited from health centres in rural and peri-urban locations in the central and eastern provinces of Rwanda. Helminth infection was diagnosed using the Kato Katz method whilst the presence of Plasmodium falciparum was identified from blood smears. The prevalence of helminth infections was 34.3%; of malaria 13.3%, and of co-infections 6.6%. Helminth infections were more common in rural (43.1%) than peri-urban (18.0%; p<0.0005) sites. A CD4 count ≤350 cells/mm3 was associated with a higher risk of helminth infections (odds ratio, 3.39; 95% CIs, 2.16–5.33; p<0.0005) and malaria (3.37 [2.11–5.38]; p<0.0005) whilst helminth infection was a risk factor for malaria infection and vice versa. Education and employment reduced the risk of all types of infection whilst hand washing protected against helminth infection (0.29 [0.19–0.46]; p<0.0005);). The TDF-3TC-NVP (3.47 [2.21–5.45]; p<0.0005), D4T-3TC-NVP (2.47 [1.27–4.80]; p<0.05) and AZT-NVP (2.60 [1.33–5.08]; p<0.05) regimens each yielded higher helminth infection rates than the AZT-3TC-NVP regimen. Anti-retroviral therapy had no effect on the risk of malaria. Conclusion/significance HIV-positive pregnant women would benefit from the scaling up of de-worming programs alongside health education and hygiene interventions. The differential effect of certain ART combinations (as observed here most strongly with AZT-3TC-NVP) possibly protecting against helminth infection warrants further

  11. Risk of HIV dementia and opportunistic brain disease in AIDS and zidovudine therapy

    PubMed Central

    Baldeweg, T.; Catalan, J.; Gazzard, B.

    1998-01-01

    OBJECTIVE—To determine the incidence of HIV dementia and opportunistic brain disease in AIDS relative to the use of licensed antiretoviral medication (zidovudine, zalcitabine, didanosine, and stavudine).
METHOD—Medical records were evaluated retrospectively in a longitudinal cohort of 1109 patients with AIDS during the period 1991-4. Treatment groups were defined by start and duration of zidovudine treatment, the drugs used most often during this period were: (a) no zidovudine, (b) zidovudine before AIDS, (c) zidovudine before and after AIDS, and (d) zidovudine used in AIDS. Main outcome measures were cumulative incidence and survival from AIDS to onset of HIV dementia, progressive multifocal leukoencephalopathy (PML), cerebral toxoplasmosis, and primary CNS lymphoma.
RESULTS—Risk of brain disease including HIV dementia and opportunistic brain disease was reduced in patients who started zidovudine before AIDS and continued in AIDS (relative risk (RR) 0.55, 95% confidence interval (95% CI) 0.36-0.84) as well as zidovudine initiated in AIDS (RR 0.27, 95% CI 0.17-0.45) compared with untreated subjects. Treatment effects were not constant over time, decreasing by 14%-32% for each six months of follow up. This was supported by unadjusted incidences across groups stratified by duration of zidovudine use, indicating reduced risk with treatment for up to 18 months but not with longer duration of use of zidovudine. Other antiretroviral drugs had no significant effect, although these were used by only 14% of patients in this cohort.
CONCLUSION—The time limited but effective neuroprotection offered by zidovudine monotherapy for <18 months suggests that non-specific mechanisms of cerebral immunological defence may benefit from antiretroviral treatment. Due to the limitations of a retrospective study these findings require confirmation and further investigation in the context of current combination drug treatments.

 PMID:9667558

  12. 3′-AZIDO-3′-DEOXYTHYMIDINE (AZT) IS A COMPETITIVE INHIBITOR OF THYMIDINE PHOSPHORYLATION IN ISOLATED RAT HEART AND LIVER MITOCHONDRIA

    PubMed Central

    Lynx, Matthew D.; McKee, Edward E.

    2006-01-01

    Long-term use of 3′-azido-3′deoxythymidine (AZT) is associated with various tissue toxicities, including hepatotoxicity and cardiomyopathy, and with mitochondrial DNA depletion. AZT-5′-triphosphate (AZTTP) is a known inhibitor of the mitochondrial DNA polymerase γ and has been targeted as the source of the mitochondrial DNA depletion. However, in previous work from this laboratory with isolated rat heart and liver mitochondria, AZT itself was shown to be a more potent inhibitor of thymidine phosphorylation (IC50 of 7.0 ± 1.0 μM AZT in heart mitochondria and of 14.4 ± 2.6 μM AZT in liver mitochondria) than AZTTP is of polymerase γ (IC50 of >100 μM AZTTP), suggesting that depletion of mitochondrial stores of TTP may limit replication and could be the cause of the mitochondrial DNA depletion observed in tissues affected by AZT toxicity. The purpose of this work is to characterize the nature of AZT inhibition of thymidine phosphorylation in isolated rat heart and rat liver mitochondria. In both of these tissues, AZT was found to be a competitive inhibitor of the phosphorylation of thymidine to TMP, catalyzed by thymidine kinase 2. The inhibition constant (Ki) for heart mitochondria is 10.6 ± 4.5 μM AZT, and for liver mitochondria Ki is 14.0 ± 2.5 μM AZT. Since AZT is functioning as a competitive inhibitor, increasing thymidine concentrations may be one mechanism to overcome the inhibition and decrease AZT-related toxicity in these tissues. PMID:16720018

  13. Biowaiver monographs for immediate-release solid oral dosage forms: Zidovudine (azidothymidine).

    PubMed

    Soares, Kelen C C; Rediguieri, Camila F; Souza, Jacqueline; Serra, Cristina Helena R; Abrahamsson, Bertil; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James E; Shah, Vinod P; Dressman, Jennifer

    2013-08-01

    Literature data on the properties of zidovudine relevant to waiver of in vivo bioequivalence (BE) testing requirements for the approval of immediate-release (IR) solid oral dosage forms containing zidovudine alone or in combination with other active pharmaceutical ingredients (APIs) are reviewed. Solubility, dissolution, and permeability data for zidovudine, along with its dosing schedule, therapeutic index and pharmacokinetic properties, and reports related to BE/bioavailability were all taken into consideration. Data for solubility and permeability suggest that zidovudine belongs to Class I according to the Biopharmaceutics Classification System. Also, zidovudine is not a narrow therapeutic index drug. Although five out of 13 formulations tested in vivo (mostly of unreported composition) failed to show BE, it appears that in vitro studies performed according to biowaiver methods could predict in vivo behavior. Nevertheless, it is highly recommended that if a biowaiver is to be applied, excipient choices be limited to those found in IR drug products approved in International Conference on Harmonisation (ICH) or associated countries in the same dosage form (Table 2 of this monograph), in their usual amounts. These conclusions apply to products containing zidovudine as the only API and also to fixed combination products containing zidovudine with respect to the zidovudine component of the formulation. Copyright © 2013 Wiley Periodicals, Inc.

  14. Zidovudine-induced nail pigmentation in a 12-year-old boy.

    PubMed

    Chawre, Sanjeevani M; Pore, Shraddha M; Nandeshwar, Manish B; Masood, Nausheen M

    2012-01-01

    Zidovudine is an important component of first-line antiretroviral treatment (ART) regimens used to manage pediatric HIV. Nail pigmentation with zidovudine is a well-documented occurrence in adults, especially dark-skinned individuals. But it has so far not been reported in children. Here, we report a pediatric case of zidovudine-induced nail pigmentation. A 12-year-old boy receiving ART with zidovudine, lamivudine, and nevirapine presented to dermatology OPD with complaint of diffuse bluish-brown discoloration of all fingernails. The pigmentation was noticed by the patient after 3 months of initiating zidovudine-based regimen. It first appeared in thumb nails, gradually involved all fingernails, and increased in intensity over time. Though harmless and reversible, psychological aspects of this noticeable side effect may hamper adherence to therapy and may lead to unnecessary investigations and treatment for misdiagnosis such as cyanosis or melanoma.

  15. N348I in HIV-1 reverse transcriptase counteracts the synergy between zidovudine and nevirapine.

    PubMed

    Yap, Soo Huey; Herman, Brian D; Radzio, Jessica; Sluis-Cremer, Nicolas; Tachedjian, Gilda

    2012-10-01

    The efficacy of regimens that include both zidovudine and nevirapine can be explained by the synergistic interactions between these drugs. N348I in HIV-1 reverse transcriptase confers decreased susceptibility to zidovudine and nevirapine. Here, we demonstrate that N348I reverses the synergistic inhibition of HIV-1 by zidovudine and nevirapine. Also, the efficiency of zidovudine-monophosphate excision in the presence of nevirapine is greater for N348I HIV-1 reverse transcriptase compared with the wild-type enzyme. These data help explain the frequent selection of N348I in regimens that contain zidovudine and nevirapine, and suggest that the selection of N348I should be monitored in resource-limited settings where these drugs are routinely used.

  16. Synthesis and antiviral activity of boranophosphonate isosteres of AZT and d4T monophosphates.

    PubMed

    Barral, Karine; Priet, Stéphane; De Michelis, Céline; Sire, Joséphine; Neyts, Johan; Balzarini, Jan; Canard, Bruno; Alvarez, Karine

    2010-02-01

    We report synthesis, in vitro antiviral activity, and stability studies in biological media of original boranophosphonate isosteres of AZT and d4T monophophates. A convenient route for the synthesis of 3'-Azido-3'-deoxythymidine-5'-boranophosphonate 8 and 2',3'-Didehydro-3'-dideoxythymidine-5'-boranophosphonate 12 is described. H-phosphinates 7 and 11, and alpha-boranophosphonates 8 and 12 exhibited no significant in vitro activity against HIV-infected cells, neither against a broad panel of viruses, up to 200 microM. The absence of activity of target compounds 8 and 12 can be partially explained by their short half-life in culture medium.

  17. Progress cargo spacecraft observed with the AZT-33IK optical telescope

    NASA Astrophysics Data System (ADS)

    Klunko, Evgeniy; Eselevich, Maksim; Tergoev, Vladimir

    2016-09-01

    In this paper, we describe a telescope and measuring equipment used for optical observations of Progress cargo spacecraft (PCS), which were made during Radar-Progress space experiment sessions. We also describe object tracking and measurement techniques. The observations were made with the optical telescope AZT-33IK at Sayan Solar Observatory of ISTP SB RAS. During many of the sessions, we registered optical phenomena that occurred in regions of space surrounding PCS and appeared due to the work of PCS onboard engines. The data we obtained can be used to independently control the geometry of the experiment and to analyze physical conditions in outer space.

  18. Synthesis of AZT-PT(terpy) -- A potential compound for radiotherapy of aids

    SciTech Connect

    Mirzadeh, S.; Packard, A.B.

    1995-12-31

    The aim of this work is to evaluate a novel approach for the potential control of AIDS using radiotherapy. We propose to evaluate the combined therapeutic effectiveness of the Auger-electron emitter {sup 195m}Pt when it is attached to AZT and other related nucleoside drugs. Auger electrons penetrate only a short distance in tissue, thus the radiation dose will be confined to the infected cells only. With this approach, we expect to target not only the infected cells but also the mononuclear macro-phages which engulf the dead cells. It has been shown that chloro(2, 2`,6`,2``-terpyridine)Pt(II).

  19. Synthesis optimization for production of AZT, FLT and other AIDS/cancer-treatment drugs

    SciTech Connect

    Gakh, A.A.; Janney, M.A.; Hagaman, E.W.; Buchanan, A.C. III

    1996-12-31

    Current synthetic schemes for production of AZT, FLT and other modified nucleosides used for AIDS/CANCER chemotherapy include 5-OH protection/deprotection sequences. Although transformations of protected nucleosides can typically be performed in higher yields and selectivity than unprotected ones, the use of protecting/deprotecting reagents and procedures reduces overall effectiveness of these schemes. We have found that in many cases satisfactory yields and selectivities can be achieved by using unprotected nucleosides. These results were achieved by careful optimization of reaction conditions (solvent/reagent/temperature/time), and by using microwave heating. The structures of by-products were elucidated, and rational methods for separation and purification were developed.

  20. Retroviral Diversity and Distribution in Vertebrates

    PubMed Central

    Herniou, Elisabeth; Martin, Joanne; Miller, Karen; Cook, James; Wilkinson, Mark; Tristem, Michael

    1998-01-01

    We used the PCR to screen for the presence of endogenous retroviruses within the genomes of 18 vertebrate orders across eight classes, concentrating on reptilian, amphibian, and piscine hosts. Thirty novel retroviral sequences were isolated and characterized by sequencing approximately 1 kb of their encoded protease and reverse transcriptase genes. Isolation of novel viruses from so many disparate hosts suggests that retroviruses are likely to be ubiquitous within all but the most basal vertebrate classes and, furthermore, gives a good indication of the overall retroviral diversity within vertebrates. Phylogenetic analysis demonstrated that viruses clustering with (but not necessarily closely related to) the spumaviruses and murine leukemia viruses are widespread and abundant in vertebrate genomes. In contrast, we were unable to identify any viruses from hosts outside of mammals and birds which grouped with the other five currently recognized retroviral genera: the lentiviruses, human T-cell leukemia-related viruses, avian leukemia virus-related retroviruses, type D retroviruses, and mammalian type B retroviruses. There was also some indication that viruses isolated from individual vertebrate classes tended to cluster together in phylogenetic reconstructions. This implies that the horizontal transmission of at least some retroviruses, between some vertebrate classes, occurs relatively infrequently. It is likely that many of the retroviral sequences described here are distinct enough from those of previously characterized viruses to represent novel retroviral genera. PMID:9621058

  1. Health literacy predicts pediatric dosing accuracy for liquid zidovudine.

    PubMed

    Howard, Leigh M; Tique, José A; Gaveta, Sandra; Sidat, Mohsin; Rothman, Russell L; Vermund, Sten H; Ciampa, Philip J

    2014-04-24

    Little is known about adult caregivers' ability to accurately dose pediatric antiretroviral medications. We aimed to characterize the frequency of dosing errors for liquid zidovudine using two dosing devices and to evaluate the association between HIV literacy and dosing errors in adults living with HIV infection. Cross-sectional study enrolling 316 adults receiving combination antiretroviral therapy (cART) for HIV infection in Maputo Province, Mozambique. Participants were administered the HIV Literacy Test (HIV-LT) and asked to measure 2.5 ml of liquid zidovudine using both a cup and syringe. Dosing measurement errors for liquid zidovudine were defined as 'any error' (≥ 20% deviation from reference dose) and 'major error' (≥ 40% deviation from reference dose). Dosing errors were common using the cup (any error: 50%, major error: 28%) and syringe (any error: 48% of participants, major error: 28%). There were no significant differences in proportions of any dosing error (P=0.61) or major dosing errors (P=0.82) between dosing instruments. In multivariable models, associations (P ≤ 0.03) were found between higher HIV-LT score and dosing errors for both the cup [any error adjusted odds ratio, AOR: 0.91 (0.84-0.99), major error AOR: 0.84 (0.75-0.92)] and syringe [any error AOR: 0.82 (0.75-0.90), major error AOR: 0.88 (0.80-0.97)]. Liquid antiretroviral medications are critical for prevention and treatment of pediatric HIV infections, yet dosing errors were exceedingly common in this population and were significantly associated with lower HIV literacy levels. Targeted interventions are needed to improve HIV knowledge and skills for pediatric medication dosing, particularly for caregivers with limited literacy.

  2. Self-assemblies of 5'-cholesteryl-ethyl-phosphoryl zidovudine.

    PubMed

    Du, Lina; Jia, Junwei; Ge, Pingju; Jin, Yiguang

    2016-12-01

    Anti-HIV prodrugs are recently focused on due to their ability of self-assembly, macrophage targeting, and enhanced antiviral effects. Here, an amphiphilic prodrug of zidovudine, an anti-HIV nucleoside analogue, 5'-cholesteryl-ethyl-phosphoryl zidovudine (CEPZ) was synthesized. CEPZ showed some unique physicochemical properties. The solubility of CEPZ in the noncompetitive solvents chloroform and tetrahydrofuran (THF) was very high based on the hydrogen bonds between zidovudine groups, though CEPZ was sparing soluble in alcohols and almost insoluble in water. The typical amphiphilic property of CEPZ was demonstrated according to the Langmuir monolayers at the air/water interface. The LogP of CEPZ was high to 13.78, indicating the high hydrophobicity of amphiphilic CEPZ similar to phospholipids. Homogenous and stable self-assemblies were formed with the mean size of 128.7nm and the zeta potential of -35.4mV after injecting the CEPZ-in-THF solution into water. Hydrophobic interaction between the cholesteryl moieties of CEPZ could drive molecular self-assembly and lead to the formation of spherical vesicles. CEPZ self-assemblies showed strong stability even under high temperature and gravity probably due to the high surface charge. CEPZ was very slowly degraded in neutral solutions (e.g., pH 7.4), but fast in acid solutions (e.g., pH 5.0) and some tissue homogenates. CEPZ was quickly eliminated from the circulation and distributed into the mononuclear phagocyte system (MPS) including the liver, spleen and lung after bolus intravenous administration of CEPZ self-assemblies to mice. The MPS targeting effect of CEPZ self-assemblies makes them become a promising self-assembled drug delivery system to eradicate the HIV hidden in the macrophages.

  3. Bats and Rodents Shape Mammalian Retroviral Phylogeny.

    PubMed

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-11-09

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general.

  4. Bats and Rodents Shape Mammalian Retroviral Phylogeny

    PubMed Central

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-01-01

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general. PMID:26548564

  5. ADAM low- and medium-resolution spectrograph for 1.6-m AZT-33IK telescope

    NASA Astrophysics Data System (ADS)

    Afanasiev, V. L.; Dodonov, S. N.; Amirkhanyan, V. R.; Moiseev, A. V.

    2016-10-01

    We describe the design of a suspended low- and medium-resolution spectrograph ( R ≈ 300-1300) designed and made at the Special Astrophysical Observatory of the Russian Academy of Sciences for the 1.6-m AZT-33IK telescope of Sayan Observatory of the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences. We report the results of laboratory measurements of the parameters of the instrument and tests performed on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We measured the total quantum efficiency of the "spectrograph + telescope + detector" system on AZT-33IK telescope, which at its maximum reaches 56%. Such a hight transparency of the spectrograph allows it to be used with the 1.6-m telescope to determine the types and redshifts of objects with integrated magnitudes m AB ≈ 20-21, and this result was confirmed by actual observations.

  6. [Development of HIV 1 antigenemia during treatment with azidothymidine (AZT): follow-up of 90 patients for a year].

    PubMed

    Berlie, H C; Berlioux, J; Daguet, G L

    1989-06-01

    VIH 1 antigenaemia has a significant value in the follow-up of patients treated with AZT. This study of 90 patients (55 ARC - 35 AIDS), each receiving AZT for more than a year, 200 mg every 4 hours, demonstrates the prognosis value of antigenaemia at Day 0, as well as its therapeutic indication value. However, at term and under this treatment, the significance of this virological data has to be reconsidered. Various kinetic patterns are described according to the clinical status and the CD4+ cells count.

  7. MRP (ABCC) transporters-mediated efflux of anti-HIV drugs, saquinavir and zidovudine, from human endothelial cells

    PubMed Central

    Eilers, Mark; Roy, Upal; Mondal, Debasis

    2008-01-01

    The constituents of highly active anti-retroviral therapy (HAART) include HIV-1 protease inhibitors (HPIs) and nucleoside reverse transcriptase inhibitors (NRTIs). Endothelial cell (EC) barriers, especially the blood-brain-barrier (BBB) suppresses the entry of HAART drugs to subendothelial HIV-1 reservoirs. The ATP binding cassette (ABC) transporter family members, multidrug resistant-1 (MDR-1) and multidrug resistance-associated proteins (MRPs) can efflux both HPIs and NRTIs from intracellular compartments. Using brain derived ECs from non-human sources, previous studies suggested a dominant role for MDR-1 in HAART efflux from the BBB. However, due to species variations in ABC-transporter expression, drug-efflux functions using human brain ECs need to be investigated. Furthermore, role of ABC-transporters in drug-efflux from systemic EC barriers need to be studied. We monitored the expression of ABC-transporters in primary human ECs obtained from brain (HBMVECs), aorta (HAECs), pulmonary-artery (HPAECs), dermal-microvessel (HDMVECs) and umbilical vein (HUVECs). Gene expression for MDR-1 and MRPs (MRP-1 to MRP-5) were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR). Drug efflux functions were determined by calcein retention assays. Intracellular accumulation of both 3H-saquinavir (an HPI) and 3H-zidovudine (an NRTI) were also monitored in HAECs and HBMVECs. Both assays were carried out in presence of verapamil (20–60 µM) or MK-571 (12.5–50 µM) inhibitors of MDR-1 and MRPs, respectively in presence of verapamil or MK-571. The HBMVECs expressed higher levels of MRPs than MDR-1 and only MK-571 significantly (p<0.01) suppressed calcein efflux from these cells. However, both HAECs and HPAECs showed MDR-1 and MRP expression and calcein efflux was inhibited by both verapamil and MK-571. Both inhibitors suppressed 3H-saquinavir efflux from HAECs, but only MK-571 suppressed saquinavir efflux from HBMVECs. In both ECs, 3H-zidovudine efflux was only

  8. Prenatal exposure to zidovudine and risk for ventricular septal defects and congenital heart defects: data from the Antiretroviral Pregnancy Registry.

    PubMed

    Vannappagari, Vani; Albano, Jessica D; Koram, Nana; Tilson, Hugh; Scheuerle, Angela E; Napier, Melanie D

    2016-02-01

    To assess the risk for ventricular septal defects and congenital heart defects following zidovudine exposure during pregnancy using data from the Antiretroviral Pregnancy Registry. Data on 16,304 prospectively reported pregnancies were analyzed to estimate the frequency and risk of ventricular septal defects and congenital heart defects, comparing exposure between zidovudine-containing regimens and non-zidovudine antiretroviral regimens. The numerator includes defect cases in outcomes at ≥ 20 weeks of gestational age. The denominator includes live birth outcomes. Infants with chromosomal anomalies were excluded. There were 15,451 live birth outcomes; 13,073 were prenatally exposed to zidovudine-containing regimens and 2378 to non-zidovudine containing regimens. There were 36 ventricular septal defect cases: 31 exposed to prenatal zidovudine and 5 unexposed. Nine of the zidovudine-exposed cases had earliest exposure in the first trimester; 22 had second/third trimester exposure. Of the 5 ventricular septal defect cases not exposed to zidovudine, 2 had earliest exposure to non-zidovudine antiretroviral regimens in the first trimester, and 3 had exposure in the second/third trimester. The prevalence of ventricular septal defect was 0.24% (95% confidence interval: 0.16, 0.34) for infants exposed to zidovudine-containing regimens and 0.21% (95% confidence interval: 0.07, 0.49) for non-zidovudine regimens. The relative risk comparing the 2 was 1.13 (95% confidence interval: 0.44, 2.90). There were a total of 90 congenital heart defect cases; 78 were exposed prenatally to zidovudine-containing regimens, and 12 were unexposed. Twenty-six of the zidovudine-exposed cases had earliest exposure in the first trimester and 52 had second/third trimester exposure. Six congenital heart defect cases with non-zidovudine antiretroviral regimens had earliest exposure in the first trimester and 6 had exposure in the second/third trimester. The prevalence of congenital heart defects

  9. Role of inosine triphosphate pyrophosphatase gene variant on fever incidence during zidovudine antiretroviral therapy.

    PubMed

    Coelho, A V C; Silva, S P S; Zandonà, L; Stocco, G; Decorti, G; Crovella, S

    2017-01-23

    Zidovudine, the antiretroviral drug used to treat HIV infection, commonly causes adverse effects, such as systemic fever and gastrointestinal alterations. In the present study, the potential role of inosine triphosphate pyrophosphatase (ITPA) gene variant on the incidence of adverse events during antiretroviral therapy (ART) of HIV with zidovudine was discussed. Individuals from Northeastern Brazil (N = 204) receiving treatment for HIV-1 infection were recruited. Zidovudine-related adverse effects developed during the treatment were registered. The rs1127354 polymorphism in the ITPA gene was genotyped using real-time PCR to assess whether this single nucleotide polymorphism was associated with the occurrence of zidovudine-related adverse effects. We observed a significant association between the ITPA variant genotype and the reported systemic fever (odds ratio = 7.17, 95% confidence interval = 1.19-43.15; P = 0.032). Zidovudine use could indirectly lead to an increase in the levels of inosine monophosphate in an antimetabolite-like manner, which is converted to inosine triphosphate (ITP). The rs1127354 variant caused a decrease in ITPA activity, thereby leading to ITP accumulation. This in turn resulted in cytotoxicity, which was manifested by neutropenia and fever. Therefore, we hypothesized a pharmacogenetic model involving the ITPA variant genotype in multifactorial components that act together to determine the onset of zidovudine-related adverse effects.

  10. Comparing genotoxic signatures in cord blood cells from neonates exposed in utero to zidovudine or tenofovir.

    PubMed

    Vivanti, Alexandre; Soheili, Tayebeh S; Cuccuini, Wendy; Luce, Sonia; Mandelbrot, Laurent; Lechenadec, Jerome; Cordier, Anne-Gael; Azria, Elie; Soulier, Jean; Cavazzana, Marina; Blanche, Stéphane; André-Schmutz, Isabelle

    2015-07-17

    Zidovudine and tenofovir are the two main nucleos(t)ide analogs used to prevent mother-to-child transmission of HIV. In vitro, both drugs bind to and integrate into human DNA and inhibit telomerase. The objective of the present study was to assess the genotoxic effects of either zidovudine or tenofovir-based combination therapies on cord blood cells in newborns exposed in utero. We compared the aneuploid rate and the gene expression profiles in cord blood samples from newborns exposed either to zidovudine or tenofovir-based combination therapies during pregnancy and from unexposed controls (n = 8, 9, and 8, respectively). The aneuploidy rate was measured on the cord blood T-cell karyotype. Gene expression profiles of cord blood T cells and hematopoietic stem and progenitor cells were determined with microarrays, analyzed in a gene set enrichment analysis and confirmed by real-time quantitative PCRs. Aneuploidy was more frequent in the zidovudine-exposed group (26.3%) than in the tenofovir-exposed group (14.2%) or in controls (13.3%; P < 0.05 for both). The transcription of genes involved in DNA repair, telomere maintenance, nucleotide metabolism, DNA/RNA synthesis, and the cell cycle was deregulated in samples from both the zidovudine and the tenofovir-exposed groups. Although tenofovir has a lower clastogenic impact than zidovudine, gene expression profiling showed that both drugs alter the transcription of DNA repair and telomere maintenance genes.

  11. Comparing genotoxic signatures in cord blood cells from neonates exposed in utero to zidovudine or tenofovir

    PubMed Central

    Vivanti, Alexandre; Soheili, Tayebeh S.; Cuccuini, Wendy; Luce, Sonia; Mandelbrot, Laurent; Lechenadec, Jerome; Cordier, Anne-Gael; Azria, Elie; Soulier, Jean; Cavazzana, Marina; Blanche, Stéphane; André-Schmutz, Isabelle

    2015-01-01

    Objectives: Zidovudine and tenofovir are the two main nucleos(t)ide analogs used to prevent mother-to-child transmission of HIV. In vitro, both drugs bind to and integrate into human DNA and inhibit telomerase. The objective of the present study was to assess the genotoxic effects of either zidovudine or tenofovir-based combination therapies on cord blood cells in newborns exposed in utero. Design: We compared the aneuploid rate and the gene expression profiles in cord blood samples from newborns exposed either to zidovudine or tenofovir-based combination therapies during pregnancy and from unexposed controls (n = 8, 9, and 8, respectively). Methods: The aneuploidy rate was measured on the cord blood T-cell karyotype. Gene expression profiles of cord blood T cells and hematopoietic stem and progenitor cells were determined with microarrays, analyzed in a gene set enrichment analysis and confirmed by real-time quantitative PCRs. Results: Aneuploidy was more frequent in the zidovudine-exposed group (26.3%) than in the tenofovir-exposed group (14.2%) or in controls (13.3%; P < 0.05 for both). The transcription of genes involved in DNA repair, telomere maintenance, nucleotide metabolism, DNA/RNA synthesis, and the cell cycle was deregulated in samples from both the zidovudine and the tenofovir-exposed groups. Conclusion: Although tenofovir has a lower clastogenic impact than zidovudine, gene expression profiling showed that both drugs alter the transcription of DNA repair and telomere maintenance genes. PMID:25513819

  12. Comparative features of retroviral infections of livestock.

    PubMed

    Evermann, J F

    1990-01-01

    Retroviral infections of livestock have become of increasing importance due to their usefulness as comparative models for human retroviral infections and their effects upon animal health and marketability of animals and animal products nationally and internationally. This paper presents a perspective on the retroviruses of economic concern in veterinary medicine with emphasis on the importance of understanding the modes of virus transmission and the species specificity of the viruses. The retroviruses reviewed include the oncovirus, bovine leukosis virus, and the lentiviruses, equine infectious anemia virus; maedi/visna virus, caprine arthritis-encephalitis virus and bovine visna-like virus. The comparative features amongst these animal retroviruses and those of humans must be recognized by the veterinary and medical professions since the similarities in virus replication and spread by blood transfer can provide important clues in controlling and perhaps preventing human retroviruses infections, such as the human immunodeficiency virus.

  13. RTCGD: retroviral tagged cancer gene database

    PubMed Central

    Akagi, Keiko; Suzuki, Takeshi; Stephens, Robert M.; Jenkins, Nancy A.; Copeland, Neal G.

    2004-01-01

    Retroviral insertional mutagenesis in mouse hematopoietic tumors provides a potent cancer gene discovery tool in the post-genome-sequence era. To manage multiple high-throughput insertional mutagenesis screening projects, we developed the Retroviral Tagged Cancer Gene Database (RTCGD; http://RTCGD.ncifcrf.gov). A sequence analysis pipeline determines the genomic position of each retroviral integration site cloned from a mouse tumor, the distance between it and the nearest candidate disease gene(s) and its orientation with respect to the candidate gene(s). The pipeline also identifies genomic regions that are targets of retroviral integration in more than one tumor (common integration sites, CISs) and are thus likely to encode a disease gene. Users can search the database using a specified gene symbol, chromosome number or tumor model to identify both CIS genes and unique viral integration sites or compare the integration sites cloned by different laboratories using different models. As a default setting, users first review the CIS Lists and then Clone Lists. CIS Lists describe CISs and their candidate disease genes along with links to other public databases and clone lists. Clone Lists describe the viral integration site clones along with the tumor model and tumor type from which they were cloned, candidate disease gene(s), genomic position and orientation of the integrated provirus with respect to the candidate gene(s). It also provides a pictorial view of the genomic location of each integration site relative to neighboring genes and markers. Researchers can identify integrations of interest and compare their results with those for multiple tumor models and tumor types using RTCGD. PMID:14681473

  14. Retroviral DNA Transposition: Themes and Variations

    PubMed Central

    Skalka, Anna Marie

    2015-01-01

    SUMMARY Retroviruses and LTR retrotransposons are transposable elements that encapsidate the RNAs that are intermediates in the transposition of DNA copies of their genomes (proviruses), from one cell (or one locus) to another. Mechanistic similarities in DNA transposase enzymes and retroviral/retrotransposon integrases underscore the close evolutionary relationship among these elements. The retroviruses are very ancient infectious agents, presumed to have evolved from Ty3/Gypsy LTR retrotransposons (1), and DNA copies of their sequences can be found embedded in the genomes of most, if not all, members of the tree of life. All retroviruses share a specific gene arrangement and similar replication strategies. However, given their ancestries and occupation of diverse evolutionary niches, it should not be surprising that unique sequences have been acquired in some retroviral genomes and that the details of the mechanism by which their transposition is accomplished can vary. While every step in the retrovirus lifecycle is, in some sense, relevant to transposition, this Chapter focuses mainly on the early phase of retroviral replication, during which viral DNA is synthesized and integrated into its host genome. Some of the initial studies that set the stage for current understanding are highlighted, as well as more recent findings obtained through use of an ever-expanding technological toolbox including genomics, proteomics, and siRNA screening. Persistence in the area of structural biology has provided new insight into conserved mechanisms as well as variations in detail among retroviruses, which can also be instructive. PMID:25844274

  15. Molecular mechanisms of retroviral integration site selection

    PubMed Central

    Kvaratskhelia, Mamuka; Sharma, Amit; Larue, Ross C.; Serrao, Erik; Engelman, Alan

    2014-01-01

    Retroviral replication proceeds through an obligate integrated DNA provirus, making retroviral vectors attractive vehicles for human gene-therapy. Though most of the host cell genome is available for integration, the process of integration site selection is not random. Retroviruses differ in their choice of chromatin-associated features and also prefer particular nucleotide sequences at the point of insertion. Lentiviruses including HIV-1 preferentially integrate within the bodies of active genes, whereas the prototypical gammaretrovirus Moloney murine leukemia virus (MoMLV) favors strong enhancers and active gene promoter regions. Integration is catalyzed by the viral integrase protein, and recent research has demonstrated that HIV-1 and MoMLV targeting preferences are in large part guided by integrase-interacting host factors (LEDGF/p75 for HIV-1 and BET proteins for MoMLV) that tether viral intasomes to chromatin. In each case, the selectivity of epigenetic marks on histones recognized by the protein tether helps to determine the integration distribution. In contrast, nucleotide preferences at integration sites seem to be governed by the ability for the integrase protein to locally bend the DNA duplex for pairwise insertion of the viral DNA ends. We discuss approaches to alter integration site selection that could potentially improve the safety of retroviral vectors in the clinic. PMID:25147212

  16. The design of artificial retroviral restriction factors

    SciTech Connect

    Yap, Melvyn W.; Mortuza, Gulnahar B.; Taylor, Ian A.; Stoye, Jonathan P.

    2007-09-01

    In addition to the ability to bind the retroviral capsid protein, the retroviral restriction factors Fv1, Trim5{alpha} and Trim5-CypA share the common property of containing sequences that promote self-association. Otherwise Fv1 and Trim5{alpha} appear unrelated. Mutational analyses showed that restriction was invariably lost when changes designed to disrupt the sequences responsible for multimerization were introduced. A novel restriction protein could be obtained by substituting sequences from the self-associating domain of Fv1 for the Trim5 sequences in Trim5-CypA. Similarly, a fusion protein containing cyclophilin A joined to arfaptin2, a protein known to form extended dimers, was also shown to restrict HIV-1. Hence, multimerization of a capsid-binding domain could be the common minimum design feature for capsid-dependent retroviral restriction factors. However, not all domains that promote multimerization can substitute for the N-terminal domains of Fv1 and Trim5{alpha}. Moreover, only CypA can provide a capsid-binding site with different N-terminal domains. It is suggested that the spatial relationship between the multiple target binding sites may be important for restriction.

  17. Zidovudine induces visceral mitochondrial toxicity and intra-abdominal fat gain in a rodent model of lipodystrophy.

    PubMed

    Walker, Ulrich A; Lebrecht, Dirk; Reichard, Wilfried; Kirschner, Janbernd; Bissé, Emmanuel; Iversen, Line; Venhoff, Ana C; Venhoff, Nils

    2014-01-01

    The use of zidovudine is associated with a loss of subcutaneous adipose tissue (SAT). We assessed if zidovudine treatment also affects visceral adipose tissue (VAT) and if uridine supplementation abrogates the adverse effects of zidovudine on VAT. Rats were fed zidovudine for 21 weeks with or without simultaneous uridine supplementation. Control animals did not receive zidovudine, or were treated with uridine alone. Changes in SAT and VAT were monitored by magnetic resonance imaging. Adipose tissue was examined for structural and molecular signs of mitochondrial toxicity. Zidovudine induced lipoatrophy in SAT and fat hypertrophy in VAT. Compared with controls zidovudine-exposed VAT adipocytes had increased diameters, microvesicular steatosis and enlarged mitochondria with disrupted crystal architecture on electron microscopy. VAT adipocyte mitochondrial DNA (mtDNA) copy numbers were diminished, as were mtDNA-encoded respiratory chain proteins. The 'common' mtDNA deletion was detected in high frequencies in zidovudine treated animals, but not in the controls. Although mtDNA depletion was more profound in SAT compared with VAT, the 'common' deletion tended to be more frequent in the VAT than in the SAT. Uridine coadministration abrogated all effects of zidovudine on VAT and SAT pathology. Zidovudine induces a gain of intra-abdominal fat in association with quantitative and qualitative alterations of the mitochondrial genome and impaired expression of mtDNA-encoded respiratory chain components, indicating that zidovudine may contribute to abdominal fat hypertrophy in HIV-infected patients. In this rodent model, uridine supplementation abrogates both SAT and VAT pathology induced by zidovudine.

  18. Transplacental Exposure to AZT Induces Adverse Neurochemical and Behavioral Effects in a Mouse Model: Protection by L-Acetylcarnitine

    PubMed Central

    Venerosi Pesciolini, Aldina; Tramutola, Antonella; Ajmone-Cat, Maria Antonietta; Cinque, Carlo; Alemà, Giovanni Sebastiano; Giovine, Angela; Peluso, Gianfranco; Minghetti, Luisa; Nicolai, Raffaella; Calamandrei, Gemma; Casolini, Paola

    2013-01-01

    Maternal-fetal HIV-1 transmission can be prevented by administration of AZT, alone or in combination with other antiretroviral drugs to pregnant HIV-1-infected women and their newborns. In spite of the benefits deriving from this life-saving prophylactic therapy, there is still considerable uncertainty on the potential long-term adverse effects of antiretroviral drugs on exposed children. Clinical and experimental studies have consistently shown the occurrence of mitochondrial dysfunction and increased oxidative stress following prenatal treatment with antiretroviral drugs, and clinical evidence suggests that the developing brain is one of the targets of the toxic action of these compounds possibly resulting in behavioral problems. We intended to verify the effects on brain and behavior of mice exposed during gestation to AZT, the backbone of antiretroviral therapy during human pregnancy. We hypothesized that glutamate, a neurotransmitter involved in excitotoxicity and behavioral plasticity, could be one of the major actors in AZT-induced neurochemical and behavioral alterations. We also assessed the antioxidant and neuroprotective effect of L-acetylcarnitine, a compound that improves mitochondrial function and is successfully used to treat antiretroviral-induced polyneuropathy in HIV-1 patients. We found that transplacental exposure to AZT given per os to pregnant mice from day 10 of pregnancy to delivery impaired in the adult offspring spatial learning and memory, enhanced corticosterone release in response to acute stress, increased brain oxidative stress also at birth and markedly reduced expression of mGluR1 and mGluR5 subtypes and GluR1 subunit of AMPA receptors in the hippocampus. Notably, administration during the entire pregnancy of L-acetylcarnitine was effective in preventing/ameliorating the neurochemical, neuroendocrine and behavioral adverse effects induced by AZT in the offspring. The present preclinical findings provide a mechanistic hypothesis for

  19. Exposure of Allium cepa root cells to zidovudine or nevirapine induces cytogenotoxic changes.

    PubMed

    Onwuamah, Chika K; Ekama, Sabdat O; Audu, Rosemary A; Ezechi, Oliver C; Poirier, Miriam C; Odeigah, Peter G C

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p=0.004), but not nevirapine dose (p=0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.

  20. Pharmacokinetic interactions between lersivirine and zidovudine, tenofovir disoproxil fumarate/emtricitabine and abacavir/lamivudine.

    PubMed

    Vourvahis, Manoli; Davis, John; Langdon, Grant; Layton, Gary; Fang, Juanzhi; Choo, Heng Wee; Hansson, Arne G; Tawadrous, Margaret

    2013-01-01

    To investigate pharmacokinetic interactions associated with coadministration of lersivirine with zidovudine, tenofovir disoproxil fumarate (DF)/emtricitabine (Truvada(®)) or abacavir/lamivudine (Epzicom(®)/Kivexa(®)). Three Phase I, open, crossover studies with two (studies 1 and 3) or three (study 2) treatment periods were conducted in healthy individuals. In study 1, individuals received zidovudine and placebo or zidovudine and lersivirine on days 1-14. In study 2, individuals received lersivirine and tenofovir DF/emtricitabine, lersivirine and placebo or tenofovir DF/emtricitabine and placebo on days 1-10. In study 3, individuals received abacavir/lamivudine only in period 1 (5 days) and abacavir/lamivudine and lersivirine in period 2 (10 days). Blood samples were taken on days 1-14 (study 1) or day of final dose (studies 2 and 3) and analysed using high performance liquid chromatography/dual mass spectrometry. Pharmacokinetic parameters were calculated by standard non-compartmental methods. When coadministered with lersivirine, zidovudine exposure increased by 35%, and exposure of its metabolite zidovudine-glucuronide decreased by 19%. Following coadministration of lersivirine and tenofovir DF/emtricitabine, tenofovir exposure increased by 30%, and lersivirine exposure decreased by 12%. Coadministration of lersivirine and abacavir/lamivudine increased abacavir exposure by 27% and decreased lamivudine exposure by 8%. Adverse events were predominantly mild in these Phase I studies. Coadministration of lersivirine with zidovudine, tenofovir DF/emtricitabine or abacavir/lamivudine influenced the systemic exposure of all nucleoside reverse transcriptase inhibitor agents investigated (except for lamivudine; emtricitabine pharmacokinetics were not assessed). Changes were not considered clinically meaningful for zidovudine and abacavir. The clinical relevance of the effect on tenofovir pharmacokinetics is currently unknown.

  1. Exposure of Allium cepa Root Cells to Zidovudine or Nevirapine Induces Cytogenotoxic Changes

    PubMed Central

    Onwuamah, Chika K.; Ekama, Sabdat O.; Audu, Rosemary A.; Ezechi, Oliver C.; Poirier, Miriam C.; Odeigah, Peter G C.

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource–poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p = 0.004), but not nevirapine dose (p = 0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced. PMID:24599327

  2. Is zidovudine therapy in pregnant HIV-infected women associated with gestational age and birthweight?

    PubMed

    1999-01-14

    Prophylactic zidovudine during pregnancy and labour reduces maternal viral load and, with neonatal therapy, has been shown to reduce vertical transmission. However, zidovudine may have additional effects. Advanced HIV disease is associated with premature delivery, which in turn results in increased vertical transmission. Data from the European Collaborative Study (ECS) were analysed to investigate whether zidovudine could be associated with decreased prematurity risk and/or with a reduced frequency of low birthweight. HIV-infected pregnant women enrolled in the ECS were followed prospectively according to a standard protocol. Gestational age was assessed by ultrasound, prematurity was defined as delivery before 37 weeks and the cut-off for low birthweight was 2500 g. We calculated odds ratios (OR) to estimate the effect of zidovudine on the risk of premature of low birthweight delivery. In 2299 mothers, zidovudine taken to reduce the risk of vertical transmission decreased the odds of premature delivery by a quarter (OR = 0.76, 95% confidence interval (CI) 0.53-1.09), and the odds of low birthweight by nearly half (OR = 0.55, 95% CI 0.39-0.79). Allowing for CD4 count and mode of delivery did not greatly alter these OR values. A multivariate analysis suggested that prophylactic zidovudine and prematurity were independently associated with risk of transmission. Our findings suggest an additional health benefit of zidovudine. Even if most vertical transmission occurs around the time of delivery, therapy earlier in pregnancy could have an indirect effect on transmission rates through delaying delivery. This hypothesis needs to be confirmed or refuted by more appropriate studies.

  3. Structure and conformational analysis of the anti-HIV AZT 5‧-aminocarbonylphosphonate prodrug using DFT methods

    NASA Astrophysics Data System (ADS)

    Tamara Molina, A.; Alcolea Palafox, M.

    2011-08-01

    A comprehensive theoretical conformational analysis of the anti-HIV AZT 5'-aminocarbonylphosphonate prodrug was carried out, due to this prodrug has noticeable advantage over approved drugs AZT and Nikavir. The whole conformational parameters ( χ, γ, β, α, δ, ɛ, τ, P, νmax) were analysed as well as the NBO Natural atomic charges. The calculations were carried out by means of B3LYP/6-31G ∗∗ and B3LYP/6-311++G(3df,pd) DFT levels of theory with full relaxation of all geometrical parameters. The search located at least 86 stable structures, 6 of which are within a 1 kcal/mol electronic energy range of the global minimum and 11 conformers are within a 1 kcal/mol Gibbs energy range. The global minimum with the 6-311++G(3df,pd) basis set corresponds to the calculated values of the exocyclic torsional angles χ = -121.6°, β = 153.0°, γ = -152.0° and α = -74.1°. The results obtained are in accordance to those found in related anti-HIV nucleoside Analogs. Comparisons of the conformers with those determined in the common anti-HIV drug AZT were carried out. Several correlations and general conclusions were emphasized.

  4. [Comparative study of two anti-antiretroviral protocols used for treatment of a cohort of HIV 1-positive patients followed at the Institute of Public Health and Hygiene in Dakar, Senegal].

    PubMed

    Sow, P G; Dia, A T; Diallo, P D; Traore; Gaye, A M

    2011-04-01

    In the last ten years, the discovery of several antiretroviral drugs has greatly contributed to improving the survival and quality of life of HIV-infected persons. The purpose of this retrospective study was to compare the effectiveness and tolerance of two anti-retroviral combinations, i.e., Lamivudine + Zidovudine and Efavirenz versus Lamivudine + Zidovudine and Nevirapine. The files of HIV1-infected patients treated between July 2003 and December 2004 (18 months) and followed at the Institute of public health and hygiene in Dakar were reviewed. A total of 70 patients, i.e., 35 in each protocol group, were included. The following data were collected for each patient: age, sex, locality, elements to assess tolerance, and elements to assess effectiveness (CD4 count, viral load and opportunistic infection immuno-failure). Results indicated that the immunovirologic effectiveness of the two protocols was identical with regard to mean CD4 count, i.e., 327 cells/mm3 for AZT+3TC+EFV versus 334 cells/mm3 for AZT+ 3TC+NVP (p < 0.05). Immuno effectiveness was better for Lamivudine + Zidovudine + Efavirenz than Lamivudine + Zidovudine + Nevirapine. Significant therapeutic advances in recent years have improved survival and quality of life in patients under retroviral treatment. There are currently many anti-retroviral molecules available and several relatively well codified therapeutic protocols.

  5. Fluorescence derivatization method for sensitive chromatographic determination of zidovudine based on the Huisgen reaction.

    PubMed

    Maeda, Yuki; Kishikawa, Naoya; Ohyama, Kaname; Wada, Mitsuhiro; Ikeda, Rie; Kuroda, Naotaka

    2014-08-15

    A novel pre-column fluorescence derivatization method for chromatographic analysis of azide compounds was developed based on the Huisgen reaction, which is a specific cycloaddition reaction between an alkyne and an azide. We designed and synthesized a fluorescent alkyne, 2-(4-ethynylphenyl)-4,5-diphenyl-1H-imidazole (DIB-ET) as a reagent. DIB-ET has a lophine skeleton carrying an alkyne acting as fluorophore and reactive center, respectively. In order to evaluate the practicality of DIB-ET, a high-performance liquid chromatography with fluorescence detection method was developed for the determination of zidovudine as a model of azide compound. Zidovudine could be reacted with DIB-ET in the presence of copper(II) sulfate and L-ascorbic acid as catalysts, and the formed derivative was detected fluorometrically. The proposed method allows sensitive and selective determination of zidovudine in plasma samples with the detection limit of 0.28ngmL(-1) at a S/N=3. Finally, the proposed method could be applied to determine the zidovudine concentration in rat plasma after administration of zidovudine without interference from biological components.

  6. Thermal stability and decomposition kinetic studies of acyclovir and zidovudine drug compounds.

    PubMed

    Shamsipur, Mojtaba; Pourmortazavi, Seied Mahdi; Beigi, Ali Akbar Miran; Heydari, Rouhollah; Khatibi, Mina

    2013-03-01

    Investigations on thermal behavior of drug samples such as acyclovir and zidovudine are interesting not only for obtaining stability information for their processing in pharmaceutical industry but also for predicting their shelf lives and suitable storage conditions. The present work describes thermal behaviors and decomposition kinetics of acyclovir and zidovudine in solid state, studied by some thermal analysis techniques including differential scanning calorimetry (DSC) and simultaneous thermogravimetry-differential thermal analysis (TG/DTA). TG analysis revealed that thermal degradation of the acyclovir and zidovudine is started at the temperatures of 400°C and 190°C, respectively. Meanwhile, TG-DTA analysis of acyclovir indicated that this drug melts at about 256°C. However, melting of zidovudine occurred at 142°C, which is 100°C before starting its decomposition (242°C). Different heating rates were applied to study the DSC behavior of drug samples in order to compute their thermokinetic and thermodynamic parameters by non-isothermal kinetic methods. Thermokinetic data showed that both drugs at the room temperature have slow degradation reaction rates and long shelf lives. However, acyclovir is considerably more thermally stable than zidovudine.

  7. Retroviral integration profiles: their determinants and implications for gene therapy.

    PubMed

    Lim, Kwang-il

    2012-04-01

    Retroviruses have often been used for gene therapy because of their capacity for the long-term expression of transgenes via stable integration into the host genome. However, retroviral integration can also result in the transformation of normal cells into cancer cells, as demonstrated by the incidence of leukemia in a recent retroviral gene therapy trial in Europe. This unfortunate outcome has led to the rapid initiation of studies examining various biological and pathological aspects of retroviral integration. This review summarizes recent findings from these studies, including the global integration patterns of various types of retroviruses, viral and cellular determinants of integration, implications of integration for gene therapy and retrovirus-mediated infectious diseases, and strategies to shift integration to safe host genomic loci. A more comprehensive and mechanistic understanding of retroviral integration processes will eventually make it possible to generate safer retroviral vector platforms in the near future.

  8. Retroviral Integrase Structure and DNA Recombination Mechanism

    PubMed Central

    Engelman, Alan; Cherepanov, Peter

    2015-01-01

    SUMMARY Due to the importance of human immunodeficiency virus type 1 (HIV-1) integrase as a drug target, the biochemistry and structural aspects of retroviral DNA integration have been the focus of intensive research during the past three decades. The retroviral integrase enzyme acts on the linear double-stranded viral DNA product of reverse transcription. Integrase cleaves specific phosphodiester bonds near the viral DNA ends during the 3′ processing reaction. The enzyme then uses the resulting viral DNA 3′-OH groups during strand transfer to cut chromosomal target DNA, which simultaneously joins both viral DNA ends to target DNA 5′-phosphates. Both reactions proceed via direct transesterification of scissile phosphodiester bonds by attacking nucleophiles: a water molecule for 3′ processing, and the viral DNA 3′-OH for strand transfer. X-ray crystal structures of prototype foamy virus integrase-DNA complexes revealed the architectures of the key nucleoprotein complexes that form sequentially during the integration process and explained the roles of active site metal ions in catalysis. X-ray crystallography furthermore elucidated the mechanism of action of HIV-1 integrase strand transfer inhibitors, which are currently used to treat AIDS patients, and provided valuable insights into the mechanisms of viral drug resistance. PMID:25705574

  9. Retroviral Integrations in Gene Therapy Trials

    PubMed Central

    Biasco, Luca; Baricordi, Cristina; Aiuti, Alessandro

    2012-01-01

    γ-Retroviral and lentiviral vectors allow the permanent integration of a therapeutic transgene in target cells and have provided in the last decade a delivery platform for several successful gene therapy (GT) clinical approaches. However, the occurrence of adverse events due to insertional mutagenesis in GT treated patients poses a strong challenge to the scientific community to identify the mechanisms at the basis of vector-driven genotoxicity. Along the last decade, the study of retroviral integration sites became a fundamental tool to monitor vector–host interaction in patients overtime. This review is aimed at critically revising the data derived from insertional profiling, with a particular focus on the evidences collected from GT clinical trials. We discuss the controversies and open issues associated to the interpretation of integration site analysis during patient's follow up, with an update on the latest results derived from the use of high-throughput technologies. Finally, we provide a perspective on the future technical development and on the application of these studies to address broader biological questions, from basic virology to human hematopoiesis. PMID:22252453

  10. Sustained high proportion of zidovudine-resistant HIV variants despite prolonged substitution of zidovudine by other nucleoside reverse transcriptase inhibitors.

    PubMed

    Bélec, Laurent; Legoff, Jérôme; Si-Mohamed, Ali; Andréoletti, Laurent; Mbopi-Kéou, François-Xavier; Kolberg, Janice; Matta, Mathieu; Detmer, Jill; Piketty, Christophe; Kazatchkine, Michel D

    2002-09-01

    The consequences of zidovudine (ZDV) replacement by other nucleoside reverse transcriptase inhibitors on the expression of resistance mutations at codons 215 and 41 of the reverse transcriptase (RT) gene was investigated prospectively in 66 patients harboring mutant genotypes who were changed to an effective two- or three-drug combination antiretroviral regimen. Quantitation of mutant (MUT) viral populations at codon 215 by means of RT-PCR with differential hybridization of amplicons specific for MUT and wild (WT) variants revealed no difference in the proportion of 215 MUT variants prior to (93.5 +/- 2.4%) and 12 to 20 months after (96.9 +/- 1.9%) ZDV replacement, independently of a therapeutic change for stavudine. The fitness of the variants harboring the ZDV-resistant MUT 215 genotype following drug withdrawal was calculated to be 96 to 99% of that of the variants harboring the WT 215 genotype. The apparent stability of ZDV-resistant variants in the study population may have two main complementary explanations: persistent selective pressure secondary to partial cross-resistance due to the new regimens given after the therapeutic alteration and suppression of viral replication after the therapeutic alteration that could have hampered the replacement of less fit variants by fitter variants. These findings indicate that, at least within 15 months following discontinuation of ZDV, an effective antiretroviral therapy is insufficient to allow for ZDV-resistant strains to disappear, and thus to allow for the safe re-introduction of the drug.

  11. Prevention of perinatal transmission of zidovudine- and nevirapine-resistant HIV.

    PubMed

    Cha, Agnes; Elsamadisi, Pansy; Su, Christy Peggy; Phipps, Emmet; Birnbaum, Jeffrey M

    2016-04-01

    The use of a three-drug regimen for the prevention of perinatal transmission of zidovudine- and nevirapine-resistant HIV is described. A 17-year-old Hispanic woman infected with HIV arrived at our clinic for the management of her first pregnancy. The patient was in her second trimester of her pregnancy, had not previously been treated with antiretroviral therapy, and was only taking daily prenatal vitamins at the time of her first clinic visit. Her HIV RNA viral load was 240 copies/mL, and the virus was resistant to both zidovudine and nevirapine. Nelfinavir (compounded suspension), lamivudine, and zidovudine were prescribed for the mother, though she was generally nonadherent to therapy. Nelfinavir, lamivudine, and zidovudine were initiated for the newborn within eight hours of delivery. Six months later, the patient returned to the clinic in the first trimester of her second pregnancy. At this visit, her HIV RNA viral load was 120 copies/mL. After the birth of her second child, the infant received the same regimen received by her firstborn: zidovudine 4 mg/kg orally twice daily for six weeks, lamivudine 2 mg/kg orally twice daily for two weeks, and nelfinavir 55 mg/kg orally twice daily for two weeks. At four months of age, each infant was found to be HIV-negative. A prophylactic regimen that included nelfinavir, lamivudine, and zidovudine was used to prevent perinatal transmission of HIV in two neonates. The regimen was well tolerated, and both infants were determined to be HIV-negative at four months of age. Copyright © 2016 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  12. Cytokine and sex hormone effects on zidovudine- and lamivudine-triphosphate concentrations in vitro

    PubMed Central

    Anderson, Peter L.; King, Tracy; Zheng, Jia-Hua; MaWhinney, Samantha

    2008-01-01

    Introduction Elevated zidovudine- and lamivudine-triphosphates have been observed in peripheral blood mononuclear cells (PBMCs) from females versus males and in patients with high inflammatory states versus lower inflammatory states. Consistent with high triphosphate exposures, these same patient groups also experience elevated rates of toxicity, including lipoatrophy. The purpose of this study was to evaluate the effects of oestradiol, progesterone and testosterone as well as tumour necrosis factor (TNF)-α and interferon (IFN)-α on zidovudine- and lamivudine-triphosphates in PBMCs and, for the cytokines, in 3T3-L1 adipocytes. Methods Multiple replicates of adipocytes and human PBMCs were incubated with experimental versus control conditions using several cytokine and sex hormone doses. Zidovudine- and lamivudine-triphosphate concentrations were determined with validated LC-MS-MS assays. A mixed effects, cell means model that accounted for experiment number was used to evaluate the effects of experimental conditions relative to control. Results In adipocytes, TNF-α doses below 2 ng/mL increased zidovudine-triphosphate by 18% (5–31%). Lamivudine-triphosphate was not detectable in adipocytes. In PBMCs, pooled IFN-α doses (0.1–10 U/mL) decreased zidovudine-triphosphate 26% (10–42%); 100 and 1000 ng/mL of progesterone decreased lamivudine-triphosphate by 22% (1–43%) and 47% (25–68%), respectively. Pooled testosterone doses (10–1000 ng/mL) decreased lamivudine-triphosphate by 24% (7–41%). No other statistically significant effects were observed. Conclusions We found evidence that sex hormones and cytokines influence zidovudine-triphosphate and lamivudine-triphosphate slightly in PBMCs and adipocytes in vitro. These findings provide insight and scientific direction to address inflammation-dependent and sex-dependent phosphorylation and responses in patients. PMID:18567572

  13. Immobilization of Zidovudine Derivatives on the SBA-15 Mesoporous Silica and Evaluation of Their Cytotoxic Activity.

    PubMed

    Lewandowski, Dawid; Lewandowska, Marta; Ruszkowski, Piotr; Pińska, Anita; Schroeder, Grzegorz

    2015-01-01

    Novel zidovudine derivatives, able to be covalently conjugated to silica surface, have been obtained and grafted to SBA-15 mesoporous silica. Cytotoxic activity of the hybrid organic-inorganic (zidovudine derivatives-silica) systems against HeLa and KB cell lines has been analyzed. Addition of folic acid had a positive influence on the cytotoxicity. Up to 69% of HeLa and 65% of KB tumor cells growth inhibition has been achieved at low silica concentration used (10 μg/mL).

  14. Immobilization of Zidovudine Derivatives on the SBA-15 Mesoporous Silica and Evaluation of Their Cytotoxic Activity

    PubMed Central

    Lewandowski, Dawid

    2015-01-01

    Novel zidovudine derivatives, able to be covalently conjugated to silica surface, have been obtained and grafted to SBA-15 mesoporous silica. Cytotoxic activity of the hybrid organic-inorganic (zidovudine derivatives-silica) systems against HeLa and KB cell lines has been analyzed. Addition of folic acid had a positive influence on the cytotoxicity. Up to 69% of HeLa and 65% of KB tumor cells growth inhibition has been achieved at low silica concentration used (10 μg/mL). PMID:25942021

  15. Biochemical Characterization of Novel Retroviral Integrase Proteins

    PubMed Central

    Ballandras-Colas, Allison; Naraharisetty, Hema; Li, Xiang; Serrao, Erik; Engelman, Alan

    2013-01-01

    Integrase is an essential retroviral enzyme, catalyzing the stable integration of reverse transcribed DNA into cellular DNA. Several aspects of the integration mechanism, including the length of host DNA sequence duplication flanking the integrated provirus, which can be from 4 to 6 bp, and the nucleotide preferences at the site of integration, are thought to cluster among the different retroviral genera. To date only the spumavirus prototype foamy virus integrase has provided diffractable crystals of integrase-DNA complexes, revealing unprecedented details on the molecular mechanisms of DNA integration. Here, we characterize five previously unstudied integrase proteins, including those derived from the alpharetrovirus lymphoproliferative disease virus (LPDV), betaretroviruses Jaagsiekte sheep retrovirus (JSRV), and mouse mammary tumor virus (MMTV), epsilonretrovirus walleye dermal sarcoma virus (WDSV), and gammaretrovirus reticuloendotheliosis virus strain A (Rev-A) to identify potential novel structural biology candidates. Integrase expressed in bacterial cells was analyzed for solubility, stability during purification, and, once purified, 3′ processing and DNA strand transfer activities in vitro. We show that while we were unable to extract or purify accountable amounts of WDSV, JRSV, or LPDV integrase, purified MMTV and Rev-A integrase each preferentially support the concerted integration of two viral DNA ends into target DNA. The sequencing of concerted Rev-A integration products indicates high fidelity cleavage of target DNA strands separated by 5 bp during integration, which contrasts with the 4 bp duplication generated by a separate gammaretrovirus, the Moloney murine leukemia virus (MLV). By comparing Rev-A in vitro integration sites to those generated by MLV in cells, we concordantly conclude that the spacing of target DNA cleavage is more evolutionarily flexible than are the target DNA base contacts made by integrase during integration. Given their

  16. Impact of HIV Infection and Zidovudine Therapy on RBC Parameters and Urine Methylmalonic Acid Levels.

    PubMed

    Adediran, Adewumi; Osunkalu, Vincent; Wakama, Tamunomieibi; John-Olabode, Sarah; Akinbami, Akinsegun; Uche, Ebele; Akanmu, Sulaimon

    2016-01-01

    Background. Anaemia is a common complication of human immunodeficiency virus (HIV) infection. The aim of this study was to investigate the impact of HIV infection and zidovudine on red blood cells (RBC) parameters and urine methylmalonic acid (UMMA) levels in patients with HIV infection. Material and Methods. A cross-sectional study involving 114 subjects, 94 of which are HIV-infected nonanaemic and 20 HIV negative subjects (Cg) as control. Full blood count parameters and urine methylmalonic acid (UMMA) level of each subject were determined. Associations were determined by Chi-square test and logistic regression statistics where appropriate. Results. Subjects on zidovudine-based ART had mean MCV (93 fL) higher than that of control group (82.9 fL) and ART-naïve (85.9 fL) subjects and the highest mean RDW. Mean UMMA level, which reflects vitamin B12 level status, was high in all HIV-infected groups but was significantly higher in ART-naïve subjects than in ART-experienced subjects. Conclusion. Although non-zidovudine therapy may be associated with macrocytosis (MCV > 95 fL), zidovudine therapy and ART naivety may not. Suboptimal level of vitamin B12 as measured by high UMMA though highest in ART-naïve subjects was common in all HIV-infected subjects.

  17. Trimethoprim, alone or in combination with sulphamethoxazole, decreases the renal excretion of zidovudine and its glucuronide.

    PubMed Central

    Chatton, J Y; Munafo, A; Chave, J P; Steinhäuslin, F; Roch-Ramel, F; Glauser, M P; Biollaz, J

    1992-01-01

    Trimethoprim and trimethoprim-sulphamethoxazole (co-trimoxazole) are often prescribed in HIV patients treated with zidovudine. The pharmacokinetics of zidovudine, after a dose of 3 mg kg-1 by constant rate intravenous infusion over 1 h were evaluated in nine HIV patients in an open, randomized, three-phase crossover study, without and with trimethoprim (150 mg) and trimethoprim-sulphamethoxazole (160 and 800 mg). The metabolic clearance of zidovudine was not significantly influenced by trimethoprim-sulphamethoxazole and trimethoprim. However, the renal clearance of zidovudine was decreased by 58 and 48%, respectively, and that of its glucuronide by 27 and 20% (P < 0.05). The fraction of the dose excreted as the parent compound fell by 47 and 39% and the metabolic ratio by 48 and 43% (P < 0.05). This kinetic drug interaction, apparently due solely to trimethoprim, may only be clinically important when hepatic glucuronidation is also impaired by liver disease or inhibited by other drugs. PMID:1493087

  18. Evaluation of the Activity of Lamivudine and Zidovudine against Ebola Virus

    PubMed Central

    Hart, Brit J.; DeWald, Lisa Evans; Johnson, Joshua C.; Postnikova, Elena; Zhou, Huanying; Gross, Robin; Rojas, Oscar; Alexander, Isis; Josleyn, Nicole; Zhang, Tengfei; Michelotti, Julia; Janosko, Krisztina; Glass, Pamela J.; Flint, Mike; McMullan, Laura K.; Spiropoulou, Christina F.; Mierzwa, Tim; Guha, Rajarshi; Shinn, Paul; Michael, Sam; Klumpp-Thomas, Carleen; McKnight, Crystal; Thomas, Craig; Eakin, Ann E.; O’Loughlin, Kathleen G.; Green, Carol E.; Catz, Paul; Mirsalis, Jon C.; Honko, Anna N.; Olinger, Gene G.; Bennett, Richard S.; Holbrook, Michael R.; Hensley, Lisa E.; Jahrling, Peter B.

    2016-01-01

    In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 μM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 μg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD

  19. Evaluation of the Activity of Lamivudine and Zidovudine against Ebola Virus.

    PubMed

    Cong, Yu; Dyall, Julie; Hart, Brit J; DeWald, Lisa Evans; Johnson, Joshua C; Postnikova, Elena; Zhou, Huanying; Gross, Robin; Rojas, Oscar; Alexander, Isis; Josleyn, Nicole; Zhang, Tengfei; Michelotti, Julia; Janosko, Krisztina; Glass, Pamela J; Flint, Mike; McMullan, Laura K; Spiropoulou, Christina F; Mierzwa, Tim; Guha, Rajarshi; Shinn, Paul; Michael, Sam; Klumpp-Thomas, Carleen; McKnight, Crystal; Thomas, Craig; Eakin, Ann E; O'Loughlin, Kathleen G; Green, Carol E; Catz, Paul; Mirsalis, Jon C; Honko, Anna N; Olinger, Gene G; Bennett, Richard S; Holbrook, Michael R; Hensley, Lisa E; Jahrling, Peter B

    2016-01-01

    In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 μM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 μg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD.

  20. Tenofovir or zidovudine in second-line antiretroviral therapy after stavudine failure in southern Africa.

    PubMed

    Wandeler, Gilles; Gerber, Florian; Rohr, Julia; Chi, Benjamin H; Orrell, Catherine; Chimbetete, Cleophas; Prozesky, Hans; Boulle, Andrew; Hoffmann, Christopher J; Gsponer, Thomas; Fox, Matthew P; Zwahlen, Marcel; Egger, Matthias

    2014-01-01

    There is debate over using tenofovir or zidovudine alongside lamivudine in second-line antiretroviral therapy (ART) following stavudine failure. We analysed outcomes in cohorts from South Africa, Zambia and Zimbabwe Patients aged ≥16 years who switched from a first-line regimen including stavudine to a ritonavir-boosted lopinavir-based second-line regimen with lamivudine or emtricitabine and zidovudine or tenofovir in seven ART programmes in southern Africa were included. We estimated the causal effect of receiving tenofovir or zidovudine on mortality and virological failure using Cox proportional hazards marginal structural models. Its parameters were estimated using inverse probability of treatment weights. Baseline characteristics were age, sex, calendar year and country. CD4(+) T-cell count, creatinine and haemoglobin levels were included as time-dependent confounders. A total of 1,256 patients on second-line ART, including 958 on tenofovir, were analysed. Patients on tenofovir were more likely to have switched to second-line ART in recent years, spent more time on first-line ART (33 versus 24 months) and had lower CD4(+) T-cell counts (172 versus 341 cells/μl) at initiation of second-line ART. The adjusted hazard ratio comparing tenofovir with zidovudine was 1.00 (95% CI 0.59, 1.68) for virological failure and 1.40 (0.57, 3.41) for death. We did not find any difference in treatment outcomes between patients on tenofovir or zidovudine; however, the precision of our estimates was limited. There is an urgent need for randomized trials to inform second-line ART strategies in resource-limited settings.

  1. Evaluation of incidence of zidovudine induced anemia in Indian human immunodeficiency virus positive patients in comparison with stavudine based highly active antiretroviral therapy.

    PubMed

    Rajesh, Radhakrishnan; Vidyasagar, Sudha; Varma, Danturulu Muralidhar; Mohiuddin, Shabaz; Noorunnisa

    2011-01-01

    In patients infected with human immunodeficiency virus (HIV), zidovudine has been known to cause a severe anemia that resolves promptly when the drug is stopped. The study was aimed to assess the incidence, the pattern of occurrence of zidovudine induced anemia, causality, severity, predictability, preventability and to identify risk factors for zidovudine induced anemia in Indian HIV positive patients in comparision with stavudine based highly active antiretroviral therapy (HAART). This was a prospective observational study conducted over a period of 6 months by clinical pharmacists. Enrolled HIV positive patients were intensively monitored for zidovudine and stavudine induced anemia. zidovudine and stavudine fixed dose drug combinations of antiretroviral therapy (ART) were only included. The World Health Organization (WHO)/AIDS Clinical Trials Group (ACTG) definition of a severity grading of anemia was adopted. Each reported case of zidovudine and stavudine induced anemia was assessed for its causality by using the WHO probability scale and also with Naranjo's algorithm. Preventability was assessed using Schumock and Thornton criteria and severity was assessed using the modified Hartwig and Siegel scale. Multivariate logistic regression was used to evaluate the influence of zidovudine induced anemia. P-value < 0.05 was considered as statistically significant. Monitoring of ninety eight HIV positive patients with fixed dose highly active antiretroviral therapy identified 19 cases of zidovudine induced anemia and 2 cases of stavudine induced anemia from 55 and 43 patients respectively. Incidence of zidovudine induced anemia in intensively monitored HIV positive patients was found to be 34.5%. Chi Square tests identified statistically significant incidence differences of anemia (p < 0.05) between the zidovudine group and the stavudine group. Grade 2 and grade 4 anemia accounted for 42.1%. Causality was 'probable' by WHO probability scale and 'definite' and 'probable

  2. Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors

    PubMed Central

    Bii, Victor M.; Trobridge, Grant D.

    2016-01-01

    Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types. PMID:27792127

  3. Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors.

    PubMed

    Bii, Victor M; Trobridge, Grant D

    2016-10-25

    Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types.

  4. Highly Active Antiretroviral Therapy versus Zidovudine for Prevention of Mother-to-Child Transmission in a Programmatic Setting, Botswana

    PubMed Central

    Dryden-Peterson, Scott; Jayeoba, Oluwemimo; Hughes, Michael D.; Jibril, Haruna; Keapoletswe, Koona; Tlale, Josephine; Modise, Taolo A.; Asmelash, Aida; Moyo, Sikhulile; van Widenfelt, Erik; Makhema, Joseph; Essex, Max; Shapiro, Roger L.; Lockman, Shahin

    2011-01-01

    Few studies have compared the programmatic effectiveness of the recommended strategies of antenatal highly-active antiretroviral therapy (HAART) and zidovudine for prevention of mother-to-child transmission (MTCT). We prospectively followed infants (93% formula-fed) whose mothers who took either HAART (258 infants) or zidovudine (170 infants) during pregnancy in the Botswana national program. Overall, 10 infants (2.5%) acquired HIV— 9 infants in the zidovudine group (5.5%, 95%CI 2.6-10.2%) and 1 infant in the HAART group (0.4%, 95%CI 0.0-2.2%). Maternal HAART was associated with decreased MTCT (P=0.001) and improved HIV-free survival (P=0.040) compared with zidovudine (with or without single-dose nevirapine) in a programmatic setting. PMID:21792062

  5. FT-IR method development and validation for quantitative estimation of zidovudine in bulk and tablet dosage form.

    PubMed

    Bansal, R; Guleria, A; Acharya, P C

    2013-04-01

    New, simple and cost effective infrared spectroscopic method has been developed for the estimation of zidovudine (CAS 30516-87-1) in bulk and tablet dosage form. The quantitative analysis of zidovudine was carried out in solid form using KBr pellet method and in liquid form using quartz cuvette. These methods were developed and validated for various parameters according to ICH guidelines. Linearity range was found to be 0.8-1.6% w/w in KBr pellet method and 250-1 500 μg ml-1 in solution. The proposed methods were successfully applied for the determination of zidovudine in pharmaceutical formulation (tablets). The results demonstrated that the proposed methods are accurate, precise and reproducible (relative standard deviation<2%), while being simple, economical and less time consuming than other available methods and can be used for estimation of zidovudine in different dosage forms. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Membrane-mediated interaction between retroviral capsids

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Nguyen, Toan

    2012-02-01

    A retrovirus is an RNA virus that is replicated through a unique strategy of reverse transcription. Unlike regular enveloped viruses which are assembled inside the host cells, the assembly of retroviral capsids happens right on the cell membrane. During the assembly process, the partially formed capsids deform the membrane, giving rise to an elastic energy. When two such partial capsids approach each other, this elastic energy changes. Or in other words, the two partial capsids interact with each other via the membrane. This membrane mediated interaction between partial capsids plays an important role in the kinetics of the assembly process. In this work, this membrane mediated interaction is calculated both analytically and numerically. It is worth noting that the diferential equation determining the membrane shape in general nonlinear and cannot be solved analytically,except in the linear region of small deformations. And it is exactly the nonlinear regime that is important for the assembly kinetics of retroviruses as it provides a large energy barrier. The theory developed here is applicable to more generic cases of membrane mediated interactions between two membrane-embedded proteins.

  7. Structural basis for retroviral integration into nucleosomes.

    PubMed

    Maskell, Daniel P; Renault, Ludovic; Serrao, Erik; Lesbats, Paul; Matadeen, Rishi; Hare, Stephen; Lindemann, Dirk; Engelman, Alan N; Costa, Alessandro; Cherepanov, Peter

    2015-07-16

    Retroviral integration is catalysed by a tetramer of integrase (IN) assembled on viral DNA ends in a stable complex, known as the intasome. How the intasome interfaces with chromosomal DNA, which exists in the form of nucleosomal arrays, is currently unknown. Here we show that the prototype foamy virus (PFV) intasome is proficient at stable capture of nucleosomes as targets for integration. Single-particle cryo-electron microscopy reveals a multivalent intasome-nucleosome interface involving both gyres of nucleosomal DNA and one H2A-H2B heterodimer. While the histone octamer remains intact, the DNA is lifted from the surface of the H2A-H2B heterodimer to allow integration at strongly preferred superhelix location ±3.5 positions. Amino acid substitutions disrupting these contacts impinge on the ability of the intasome to engage nucleosomes in vitro and redistribute viral integration sites on the genomic scale. Our findings elucidate the molecular basis for nucleosome capture by the viral DNA recombination machinery and the underlying nucleosome plasticity that allows integration.

  8. Pharmacokinetics of zidovudine dosed twice daily according to World Health Organization weight bands in Ugandan HIV-infected children.

    PubMed

    Fillekes, Quirine; Kendall, Lindsay; Kitaka, Sabrina; Mugyenyi, Peter; Musoke, Philippa; Ndigendawani, Milly; Bwakura-Dangarembizi, Mutsa; Gibb, Diana M; Burger, David; Walker, Ann Sarah

    2014-05-01

    Data on zidovudine pharmacokinetics in children dosed using World Health Organization weight bands are limited. About 45 HIV-infected, Ugandan children, 3.4 (2.6-6.2) years, had intensive pharmacokinetic sampling. Geometric mean zidovudine AUC0-12h was 3.0 h.mg/L, which is higher than previously observed in adults, and was independently higher in those receiving higher doses, younger and underweight children. Higher exposure was also marginally associated with lower hemoglobin.

  9. Toxicity and clinical outcomes in patients with HIV on zidovudine and tenofovir based regimens: a retrospective cohort study

    PubMed Central

    Thuppal, Sowmyanarayanan V.; Wanke, Christine A.; Noubary, Farzad; Cohen, Joshua T.; Mwamburi, Mkaya; Ooriapdickal, Abraham C.; Muliyil, Jayaprakash; Kang, Gagandeep; Varghese, George M.; Rupali, Priscilla; Karthik, Rajiv; Sathasivam, Rajkumar; Clarance, Peace; Pulimood, Susanne A.; Peter, Dincy; George, Leni

    2015-01-01

    Background Adverse drug reactions are a major concern with zidovudine/stavudine treatment regimens. The less toxic tenofovir regimen is an alternative, but is seldom considered due to the higher costs. This study compared adverse drug reactions and other clinical outcomes resulting from the use of these two treatment regimens in India. Methods Baseline, clinical characteristics and follow-up outcomes were collected by chart reviews of HIV-positive adults and compared using univariate/multivariate analysis, with and without propensity score adjustments. Results Data were collected from 129 and 92 patients on zidovudine (with lamivudine and nevirapine) and tenofovir (with emtricitabine and efavirenz) regimens, respectively. Compared to patients receiving the zidovudine regimen, patients receiving the tenofovir regimen had fewer adverse drug reactions (47%, 61/129 vs 11%, 10/92; p<0.01), requiring fewer regimen changes (36%, 47/129 vs 3%, 3/92; p0.01). With the propensity score, the zidovudine regimen had 8 times more adverse drug reactions (p<0.01). Opportunistic infections were similar between regimens without propensity score, while the zidovudine regimen had 1.2 times (p=0.63) more opportunistic infections with propensity score. Patients on the tenofovir regimen gained more weight. Increase in CD4 levels and treatment adherence (>95%) was similar across regimens. Conclusions Patients on a tenofovir regimen have better clinical outcomes and improved general health than patients on the zidovudine regimen. PMID:25778734

  10. A method for quantitating the intracellular metabolism of AZT amino acid phosphoramidate pronucleotides by capillary high-performance liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Kim, Jisook; Park, Soobong; Tretyakova, Natalia Y; Wagner, Carston R

    2005-01-01

    A methodology has been developed for the analysis of the intracellular metabolism of 3'-azido-3'-deoxythymidine (AZT) amino acid phosphoramidates utilizing reverse-phase high-performance liquid chromatography interfaced with negative ion electrospray ionization mass spectrometry (LC/ESI(-) -MS). The presented work demonstrates the potential of capillary LC/MS and LC/MS/MS to identify and quantitate the cellular uptake and metabolism of nucleoside phosphoramidate. Significant intracellular amounts of D- and L-phenylalanine methyl ester or D- and L-tryptophan methyl ester AZT phosphoramidates were observed for human T-lymphoblastoid leukemia (CEM) cells incubated for 2 and 4 h with the prodrugs. AZT-MP was the primary metabolite observed for human T-lymphoblastoid leukemia (CEM) cells. In this paper, the details of using LC/MS to analyze AZT amino acid phosphoramidates in biological samples are discussed. LC/MS is an efficient method for analyzing multiple samples containing several analytes in a short period of time. The method also provides high selectivity and sensitivity, and requires minimal sample preparation. This approach should be broadly applicable for the analysis of the intracellular metabolism of nucleoside prodrugs and pronucleotides.

  11. Integrated strategy for the production of therapeutic retroviral vectors.

    PubMed

    Carrondo, Manuel; Panet, Amos; Wirth, Dagmar; Coroadinha, Ana Sofia; Cruz, Pedro; Falk, Haya; Schucht, Roland; Dupont, Francis; Geny-Fiamma, Cécile; Merten, Otto-Wilhelm; Hauser, Hansjörg

    2011-03-01

    The broad application of retroviral vectors for gene delivery is still hampered by the difficulty to reproducibly establish high vector producer cell lines generating sufficient amounts of highly concentrated virus vector preparations of high quality. To enhance the process for producing clinically relevant retroviral vector preparations for therapeutic applications, we have integrated novel and state-of-the-art technologies in a process that allows rapid access to high-efficiency vector-producing cells and consistent production, purification, and storage of retroviral vectors. The process has been designed for various types of retroviral vectors for clinical application and to support a high-throughput process. New modular helper cell lines that permit rapid insertion of DNA encoding the therapeutic vector of interest at predetermined, optimal chromosomal loci were developed to facilitate stable and high vector production levels. Packaging cell lines, cultivation methods, and improved medium composition were coupled with vector purification and storage process strategies that yield maximal vector infectivity and stability. To facilitate GMP-grade vector production, standard of operation protocols were established. These processes were validated by production of retroviral vector lots that drive the expression of type VII collagen (Col7) for the treatment of a skin genetic disease, dystrophic epidermolysis bullosa. The potential efficacy of the Col7-expressing vectors was finally proven with newly developed systems, in particular in target primary keratinocyte cultures and three-dimensional skin tissues in organ culture.

  12. Parameters of optical signals registered with the AZT-33IK telescope in active Radar-Progress space experiment

    NASA Astrophysics Data System (ADS)

    Eselevich, Maksim; Khakhinov, Vitaliy; Klunko, Evgeniy

    2016-09-01

    Images of Progress cargo spacecraft (PCS) and areas around them were captured by the AZT-33IK optical telescope (Sayan Observatory of ISTP SB RAS) during sessions of the active Radar-Progress space experiment. We took images of exhaust and fuel jets when propulsion systems worked and after they were cut off, during fuel system purging. In different sessions of the experiment, PCS had different orientations relative to the telescope, thus allowing us to find some parameters of the observed phenomena. These parameters make it possible to determine instants of engine ignitions, to estimate velocities of the jets, and, if necessary, to control the geometry of the space experiment. The paper reports common features of optical signals from jets measured in these experiments.

  13. Parameters of optical signals registered with the AZT-33IK telescope in active Radar-Progress space experiment

    NASA Astrophysics Data System (ADS)

    Eselevich, Maksim; Khakhinov, Vitaliy; Klunko, Evgeniy

    2016-09-01

    Images of Progress cargo spacecraft (PCS) and areas around them were captured by the AZT-33IK optical telescope (Sayan Observatory of ISTP SB RAS) during sessions of the active Radar-Progress space experiment. We took images of exhaust and fuel jets when propulsion systems worked and after they were cut off, during fuel system purging. In different sessions of the experiment, PCS had different orientations relative to the telescope, thus allowing us to find some parameters of the observed phenomena. These parameters make it possible to determine instants of engine ignitions, to estimate velocities of the jets, and, if necessary, to control the geometry of the space experiment. The paper reports common features of optical signals from jets measured in these experiments.

  14. Ethical dilemmas in continuing a zidovudine trial after early termination of similar trials.

    PubMed

    Simberkoff, M S; Hartigan, P M; Hamilton, J D; Deykin, D; Gail, M; Bartlett, J G; Feorino, P; Redfield, R; Roberts, R; Collins, D

    1993-02-01

    Ethical dilemmas caused by external events and an interim subset analysis raised concerns about continuing a long-term VA clinical trial comparing early with later zidovudine therapy for symptomatic human immunodeficiency virus (HIV) infection. The first external event was the early termination of other, apparently similar, trials conducted by the AIDS Clinical Trials Group (ACTG) and the announced clear benefits for the zidovudine-treated patients. Interim analysis of the VA trial at this time did not show similar benefits. Subset analyses were performed to explore factors that might explain the different results. These suggested a difference in response to zidovudine in white and minority groups. The Data Monitoring Board and a special advisory panel reviewed these data and concluded that, since the VA results were neutral overall and the subset analyses based on small numbers, the trial should continue. By conference call, the study cochairmen and biostatistician discussed this decision with study personnel without revealing interim results, and study personnel passed the information on to patients at the participating centers. The second event was in March 1990, when the Food and Drug Administration (FDA) approved earlier use of zidovudine, which applied to patients still in the VA trial. Patients were asked to reaffirm their participation by signing a new informed consent that explained the findings reported by the ACTG, the FDA-approved revised recommendations, and the rationale for continuation of the VA trial. The consent form emphasized that continued masked therapy was optional and that unmasked treatment and follow-up would be provided to patients requesting it. Seventy-four percent of the participants chose to continue masked therapy. We conclude that when new external data are announced, informed participation in a long-term clinical trial may require a revised consent form and that it is ethical and practical to present this without disclosure of

  15. Pharmacological Basis for Concentration-Controlled Therapy with Zidovudine, Lamivudine, and Indinavir

    PubMed Central

    Kakuda, Thomas N.; Page, Linda M.; Anderson, Peter L.; Henry, Keith; Schacker, Timothy W.; Rhame, Frank S.; Acosta, Edward P.; Brundage, Richard C.; Fletcher, Courtney V.

    2001-01-01

    Conventional antiretroviral therapy involves administration of standard fixed doses to adults and adolescents. This approach ignores interindividual variability in pharmacokinetics and results in substantial differences in systemic concentrations among patients. Thus, variability in systemic concentrations contributes to variability in response to therapy. This study was designed to evaluate the feasibility and safety of a regimen of zidovudine, lamivudine, and indinavir designed to achieve select target concentrations versus standard dose therapy. Twenty-four antiretroviral-naïve subjects completed the 24-week study; 13 received standard therapy, and 11 received concentration-controlled therapy. There were no differences in baseline characteristics. Oral clearance for all three drugs was not different between weeks 2 and 28; average ratios of week 2 oral clearance to week 28 oral clearance were 0.95, 1.09, and 1.06 for zidovudine, lamivudine, and indinavir, respectively, with 95% confidence intervals including 1. The selected target concentrations were average steady-state concentrations of 0.19 mg/liter for zidovudine and 0.44 mg/liter for lamivudine and a trough concentration of 0.15 mg/liter for indinavir; mean concentrations achieved at week 28 in the concentration-controlled arm were 0.20, 0.54, and 0.19 mg/liter, respectively. Concentration-controlled therapy significantly reduced interpatient variability in zidovudine concentrations and significantly increased indinavir concentrations. There was no difference in adverse drug effects or adherence. This investigation has provided a pharmacologic basis for concentration-controlled therapy by demonstrating that it is feasible and has a safety profile no different from that of standard therapy. Additional studies to evaluate the virologic effect of the concentration-controlled approach to antiretroviral therapy are warranted. PMID:11120972

  16. Ex vivo permeation kinetics of zidovudine from pseudolatex acrylic film across pig ear epidermis.

    PubMed

    Das, Malay K; Yelhounganba Khuman, Laishram

    2012-09-01

    The permeation of ionic compounds through lipophilic skin membrane can be enhanced by converting the impermeable ionized drug into a more permeable unionized form with pH-adjusting excipients. The osmotic influx of water into the device core, upon application on the human skin, dissolve the drug and pH-adjusting adjuvant allowing the partitioning and subsequent permeation of unionized drug from the transdermal device core. The present investigation was aimed to evaluate the feasibility of water activated pH-controlled pseudolatex films for transdermal delivery of zidovudine by ex vivo tests. The monolithic pseudolatex transdermal film of zidovudine was prepared by solvent change followed by solvent casting technique using Eudragit RL 100 and Eudragit RS 100 in varying proportions with pH 7.4 in the device core. The prepared films were of desired physicochemical properties. The SEM photomicrographs of drug loaded formulations exhibited uniformity with rough surface and no traces of crack or pores. The ex vivo skin permeation study across pig ear epidermis in Keshary-Chien glass diffusion cell showed that the drug permeability was controlled by the osmotic influx of water into the device core and consequent partition of dissolve drug into and diffusion through the skin. The formulation F2a with 10 % w/w of zidovudine dispersed in the polymer matrix composed of Eudragit RL 100 and Eudragit RS 100 at the ratio of 1:2, respectively, showed nearly the desired flux at 239.09 μg/cm(2)/h. A patch area of 117.48 cm(2) would be required for transdermal delivery of zidovudine to obtain therapeutic plasma concentration at 0.3 μg/ml.

  17. Relative Replicative Fitness of Zidovudine-Resistant Human Immunodeficiency Virus Type 1 Isolates In Vitro

    PubMed Central

    Harrigan, P. Richard; Bloor, Stuart; Larder, Brendan A.

    1998-01-01

    Replication of mixtures of two or more human immunodeficiency virus type 1 (HIV-1) variants would be expected to result in the eventual selection of the fittest virus due to Darwinian competition among the variants. The relative proportions of known HIV-1 variants (which may differ only by a single nucleotide from a standard “wild-type” virus, HIV-1HXB2) in mixed viral cultures were quantified by analysis of automated sequence signals of reverse transcriptase PCR products. With this method, the relative levels of replicative fitness of several zidovudine (3′-azidothymidine)-resistant HIV-1HXB2 variants were estimated under controlled in vitro conditions by measuring the rate of change in the proportions of viral variants as they replicated in cell cultures both in the presence and in the absence of drug selection pressure. These variants were engineered to contain commonly observed zidovudine resistance mutations in the HIV-1 reverse transcriptase (M41L, K70R, T215Y, and M41L+T215Y). In the absence of zidovudine, all variants tested displayed reduced replicative fitness compared to wild-type HIV-1HXB2. The order of relative fitness was wild type > K70R ≫ T215Y = M41L+T215Y > M41L. Mixed cultures in the presence of zidovudine showed a dose-dependent selection pressure against the wild-type virus which varied according to the resistance profile of each virus. The information gathered from this approach provides insight into competition among multiple HIV-1 variants, which likely occurs in vivo with drug selection pressure, and may be applicable in more complex mathematical models for predicting the emergence of HIV-1 variants after the initiation of antiretroviral therapy. PMID:9557659

  18. Zidovudine, abacavir and lamivudine increase the radiosensitivity of human esophageal squamous cancer cell lines.

    PubMed

    Chen, Xuan; Wang, Cong; Guan, Shanghui; Liu, Yuan; Han, Lihui; Cheng, Yufeng

    2016-07-01

    Telomerase is a type of reverse transcriptase that is overexpressed in almost all human tumor cells, but not in normal tissues, which provides an opportunity for radiosensitization targeting telomerase. Zidovudine, abacavir and lamivudine are reverse transcriptase inhibitors that have been applied in clinical practice for several years. We sought to explore the radiosensitization effect of these three drugs on human esophageal cancer cell lines. Eca109 and Eca9706 cells were treated with zidovudine, abacavir and lamivudine for 48 h before irradiation was administered. Samples were collected 1 h after irradiation. Clonal efficiency assay was used to evaluate the effect of the combination of these drugs with radiation doses of 2, 4, 6 and 8 Gy. DNA damage was measured by comet assay. Telomerase activity (TA) and relative telomere length (TL) were detected and evaluated by real-time PCR. Apoptosis rates were assessed by flow cytometric analysis. The results showed that all the drugs tested sensitized the esophageal squamous cell carcinoma (ESCC) cell lines to radiation through an increase in radiation-induced DNA damage and cell apoptosis, deregulation of TA and decreasing the shortened TL caused by radiation. Each of the drugs investigated (zidovudine, abacavir and lamivudine) could be used for sensitizing human esophageal cancer cell lines to radiation. Consequently, the present study supports the potential of these three drugs as therapeutic agents for the radiosensitization of esophageal squamous cell cancer.

  19. Photolysis of three antiviral drugs acyclovir, zidovudine and lamivudine in surface freshwater and seawater.

    PubMed

    Zhou, Chengzhi; Chen, Jingwen; Xie, Qing; Wei, Xiaoxuan; Zhang, Ya-nan; Fu, Zhiqiang

    2015-11-01

    Photodegradation is an important elimination process for many pharmaceuticals in surface waters. In this study, photodegradation of three antiviral drugs, acyclovir, zidovudine, and lamivudine, was investigated in pure water, freshwater, and seawater under the irradiation of simulated sunlight. Results showed that zidovudine was easily transformed via direct photolysis, while acyclovir and lamivudine were mainly transformed via indirect photolysis. We found that in freshwater, nitrate enhanced the photodegradation of the three antiviral drugs, bicarbonate promoted the photodegradation of acyclovir, and dissolved organic matter (DOM) accelerated the photolysis of acyclovir and lamivudine. In seawater, the photolysis of acyclovir was not susceptible to Cl(-), Br(-) and ionic strength; however, the photolysis of zidovudine was inhibited by Cl(-) and Br(-), and the photolysis of lamivudine was enhanced by Cl(-), Br(-) and ionic strength. Second-order reaction rate constants for the three antiviral drugs with (1)O2 (k1O2) and OH (kOH) were also measured. These results are important for fate and ecological risk assessment of the antiviral drugs in natural waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Effect of maraviroc on the pharmacokinetics of midazolam, lamivudine/ zidovudine, and ethinyloestradiol/ levonorgestrel in healthy volunteers

    PubMed Central

    Abel, Samantha; Russell, Deborah; Whitlock, Lyndsey A; Ridgway, Caroline E; Muirhead, Gary J

    2008-01-01

    Aims To assess the effect of maraviroc on the pharmacokinetics of midazolam, a sensitive probe CYP3A4 substrate; lamivudine/zidovudine, a combination of nucleoside reverse transcriptase inhibitors (NRTIs); and ethinyloestradiol/levonorgestrel, a combination oral contraceptive. Methods Three randomized, double-blind, placebo-controlled studies were conducted in healthy subjects to assess the effect of maraviroc on pharmacokinetics of other drugs. Two, two-period crossover studies were conducted to assess (i) the effect of steady-state maraviroc (300 mg b.i.d.) on pharmacokinetics of midazolam; and (ii) the effect of steady-state maraviroc (300 mg b.i.d.) on the pharmacokinetics of lamivudine/zidovudine. A third two-way crossover study was conducted to evaluate the effect of steady-state maraviroc (100 mg b.i.d.) on the pharmacokinetics of 30 μg ethinyloestradiol/150 μg levonorgestrel (Microgynon®). Results The geometric mean ratios for Cmax and AUC for each of the compounds tested in the presence and absence of maraviroc were between 92% and 121%. There were no notable differences in Tmax, t1/2 or CLR (where measured) for any of the compounds. Conclusions Maraviroc had no clinically relevant effects on the pharmacokinetics of the CYP3A4 substrate midazolam, the NRTIs zidovudine/lamivudine, or the oral contraceptive steroids ethinyloestradiol and levonorgestrel. PMID:18333862

  1. Use of human MAR elements to improve retroviral vector production.

    PubMed

    Buceta, M; Galbete, J L; Kostic, C; Arsenijevic, Y; Mermod, N

    2011-01-01

    Retroviral vectors have many favorable properties for gene therapies, but their use remains limited by safety concerns and/or by relatively lower titers for some of the safer self-inactivating (SIN) derivatives. In this study, we evaluated whether increased production of SIN retroviral vectors can be achieved from the use of matrix attachment region (MAR) epigenetic regulators. Two MAR elements of human origin were found to increase and to stabilize the expression of the green fluorescent protein transgene in stably transfected HEK-293 packaging cells. Introduction of one of these MAR elements in retroviral vector-producing plasmids yielded higher expression of the viral vector RNA. Consistently, viral titers obtained from transient transfection of MAR-containing plasmids were increased up to sixfold as compared with the parental construct, when evaluated in different packaging cell systems and transfection conditions. Thus, use of MAR elements opens new perspectives for the efficient generation of gene therapy vectors.

  2. Retroviral Restriction Factors and Infectious Risk in Xenotransplantation

    PubMed Central

    Meije, Yolanda; Tönjes, Ralf R.; Fishman, Jay A.

    2010-01-01

    The clinical application of xenotransplantation poses immunologic, ethical, and microbiologic challenges. Significant progress has been made in the investigation of each of these areas. Among concerns regarding infectious risks for human xenograft recipients is the identification in swine of infectious agents including porcine endogenous retroviruses (PERV) that are capable of replication in some human cell lines. PERV replication has, however, been difficult to demonstrate in primate-derived cell lines and in preclinical studies of non-human primates receiving porcine xenografts. Endogenous “retroviral restriction factors” are intracellular proteins and components of the innate immune system that act at various steps in retroviral replication. Recent studies suggest that some of these factors may have applications in the management of endogenous retroviruses in xenotransplantation. The risks of PERV infection and the potential role of retroviral restriction factors in xenotransplantation are reviewed in detail. PMID:20642677

  3. Retroviral env glycoprotein trafficking and incorporation into virions.

    PubMed

    Murakami, Tsutomu

    2012-01-01

    Together with the Gag protein, the Env glycoprotein is a major retroviral structural protein and is essential for forming infectious virus particles. Env is synthesized, processed, and transported to certain microdomains at the plasma membrane and takes advantage of the same host machinery for its trafficking as that used by cellular glycoproteins. Incorporation of Env into progeny virions is probably mediated by the interaction between Env and Gag, in some cases with the additional involvement of certain host factors. Although several general models have been proposed to explain the incorporation of retroviral Env glycoproteins into virions, the actual mechanism for this process is still unclear, partly because structural data on the Env protein cytoplasmic tail is lacking. This paper presents the current understanding of the synthesis, trafficking, and virion incorporation of retroviral Env proteins.

  4. Retroviral integration: Site matters: Mechanisms and consequences of retroviral integration site selection.

    PubMed

    Demeulemeester, Jonas; De Rijck, Jan; Gijsbers, Rik; Debyser, Zeger

    2015-11-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co-opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine-grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. © 2015 The Authors. Bioessays published by WILEY Periodicals, Inc.

  5. [Impact of zidovudine treatment and the pneumocystis carinii prophylaxis in natural history of patients with HIV infection].

    PubMed

    Sáiz Hervas, E; Castilla Castellano, V; Miquel Plaza, J; Benito Blanco, A M; Martín Llorens, M M; Pastor de Blas, M; Izquierdo, P; Muñoz Jareño, M A; Sierra, A; Nieto, M A; Moreno Collado, A M; Fraguas, C

    1998-03-01

    Early use of prophylactic regimens against Pneumocystis carinii and zidovudine therapy, may have modified the natural history of patients with HIV-1 infection. We describe the incidence of opportunistic infections and analize the mortality rate in those patients to check the occurrence of any change in the above mentioned natural history. Clinical charts of patients with HIV-1 infection attending our hospital are reviewed, from november 1987 to june 1994. We found 200 patients with AIDS, documenting 64 (32%) deaths and 69 (34.5%) patients lost to follow-up. Seven HIV-1 infected patients (3.5%) received primary prophylaxis against Pneumocystis carinii and 17 (8.5%) zidovudine therapy before developing AIDS. Patients with AIDS receiving zidovudine therapy had a higher survival (median 50 months) than those not receiving such therapy (median 17 months; p < 0.001). Ninety one patients with tuberculosis receiving zidovudine therapy had also a higher survival than those not receiving antirretroviral therapy (p < 0.01). Eighty six patients with Pneumocystis carinii pneumonia receiving zidovudine had also a higher survival (p < 0.001). Likewise, patients on zidovudine treatment had a lower reduction on CD4 lymphocyte count. The spectrum of AIDS-defining illnesses is similar to the whole country. We have not found any difference in the incidence of opportunistic infections, but we observed a trend to reduction in the incidence rate of PCP. The introduction of zidovudine therapy seems to have a positive influence on the survival of AIDS patients. This advantage is highlighted in those patients more immunodeficients at first.

  6. AZT and emodin exhibit synergistic growth-inhibitory effects on K562/ADM cells by inducing S phase cell cycle arrest and suppressing MDR1 mRNA/p-gp protein expression.

    PubMed

    Chen, Peng; Liu, Yingxia; Sun, Yanqing; Chen, Che; Qi, Yongmei; Zhang, Yingmei

    2013-12-01

    Previous studies have demonstrated that both 3'-azido-3'-deoxythymidine (AZT) and emodin, a traditional chemotherapy agent, can inhibit the growth of many types of cancer cells. This study aimed to evaluate the effect of AZT and emodin on adriamycin-resistant human chronic myelogenous leukemia (K562/ADM) cells, determine the expression of multidrug resistance 1 (MDR1) mRNA/p-glycoprotein (p-gp) protein, a protein known to induce resistance to anticancer agents, and to elucidate the underlying molecular mechanisms. K562/ADM cells were treated with AZT (10-160 μM) or emodin (5-80 μM) for 24, 48 and 72 h and cell viability was measured using the MTT assay. The effect of AZT (16.5, 33 and 66 μM) and emodin (6.1, 17.6 and 33.2 μM) on K562/ADM cell cycle distribution was determined by flow cytometry, and MDR1 mRNA/p-gp protein expression was determined by real time RT-PCR and western blotting. The growth suppression of emodin was dramatically enhanced by AZT in K562/ADM cells. The IC50 of AZT and emodin was lower than that of emodin alone. All examined combinations of AZT and emodin yielded a synergetic effect (CI < 1). Furthermore, AZT and emodin altered the cell cycle distribution and led to an accumulation of cells in S phase. Meanwhile, the expression of MDR1 mRNA/p-gp protein was markedly decreased. These results show a synergistic growth-inhibitory effect of AZT and emodin in K562/ADM cells, which is achieved through S phase arrest. MDR1 might ultimately be responsible for these phenomena.

  7. Co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection and AIDS.

    PubMed

    Shey, Muki S; Kongnyuy, Eugene J; Alobwede, Samuel M; Wiysonge, Charles Shey

    2013-03-28

    UNAIDS estimates that 34 million people are currently living with the human immunodeficiency virus (HIV) worldwide. Currently recommended regimens for initiating HIV treatment consist of either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or ritonavir-boosted protease inhibitor (PI) combined with two nucleoside reverse transcriptase inhibitors (NRTIs). However, there may be some patients for whom NNRTIs and PIs may not be appropriate. This is an update of the review published in the Cochrane Library Issue 3, 2009. To evaluate the effects of any fixed-dose combination of three NRTIs (co-formulated abacavir-lamivudine-zidovudine) for initial treatment of HIV infection. Between December 2010 and July 2011, we used standard Cochrane methods to search electronic databases and conference proceedings with relevant search terms without limits to language or publication status. We selected randomised controlled trials (RCTs) with a minimum follow-up time of six months which compared co-formulated abacavir-lamivudine-zidovudine with either PI-based or NNRTI-based therapy among antiretroviral-naive HIV-infected patients aged at least 13 years. Three authors independently selected eligible studies, assessed risk of bias, and extracted data; resolving discrepancies by consensus. We calculated the risk ratio (RR) or mean difference (MD), as appropriate, with its 95% confidence interval (CI) and conducted meta-analysis using the random-effects method because of significant statistical heterogeneity (P<0.1). We identified 15 potentially eligible RCTs, four of which met our inclusion criteria. The four included RCTs were conducted in the United States of America (USA); USA, Puerto Rico, Guatemala, Dominican Republic, and Panama; USA and Mexico; and Botswana, respectively. The RCTs compared co-formulated abacavir-lamivudine-zidovudine to treatment based on efavirenz (NNRTI), nelfinavir (PI), atazanavir (PI), and co-formulated lopinavir-ritonavir (PI), respectively

  8. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    SciTech Connect

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-08-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross-resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO-140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo.

  9. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    PubMed Central

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-01-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO 140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo. PMID:18519143

  10. Direct demonstration of retroviral recombination in a rhesus monkey.

    PubMed Central

    Wooley, D P; Smith, R A; Czajak, S; Desrosiers, R C

    1997-01-01

    Recombination may be an important mechanism for increasing variation in retroviral populations. Retroviral recombination has been demonstrated in tissue culture systems by artificially creating doubly infected cells. Evidence for retroviral recombination in vivo is indirect and is based principally on the identification of apparently mosaic human immunodeficiency virus type 1 genomes from phylogenetic analyses of viral sequences. We infected a rhesus monkey with two different molecularly cloned strains of simian immunodeficiency virus. One strain of virus had a deletion in vpx and vpr, and the other strain had a deletion in nef. Each strain on its own induced low virus loads and was nonpathogenic in rhesus monkeys. When injected simultaneously into separate legs of the same monkey, persistent high virus loads and declines in CD4+ lymphocyte concentrations were observed. Analysis of proviral DNA isolated directly from peripheral blood mononuclear cells showed that full-length, nondeleted SIVmac239 predominated by 2 weeks after infection. These results provide direct experimental evidence for genetic recombination between two different retroviral strains in an infected host. The results illustrate the ease and rapidity with which recombination can occur in an infected animal and the selection that can occur for variants generated by genetic recombination. PMID:9371629

  11. Haemoglobin recovery among HIV-1 infected patients on zidovudine-based antiretroviral therapy and other regimens in north-central Nigeria.

    PubMed

    Parrish, Deidra D; Blevins, Meridith; Megazzini, Karen M; Shepherd, Bryan E; Mohammed, Mukhtar Y; Wester, C William; Vermund, Sten H; Aliyu, Muktar H

    2014-04-01

    We conducted a study to assess trends in haemoglobin recovery among HIV-infected patients initiated on zidovudine-based combination antiretroviral therapy (cART) stratified by baseline haemoglobin level. Haemoglobin data from non-pregnant adult patients initiating cART in rural north-central Nigeria between June 2009 and May 2011 were analysed using a linear mixed effects model to assess the interaction between time, zidovudine-containing regimen and baseline haemoglobin level on the outcome of subsequent haemoglobin level. Best-fit curves were created for baseline haemoglobin in the 10th, 25th, 75th and 90th percentiles. We included 313 patients with 736 measures of haemoglobin in the analysis (239 on zidovudine and 74 on non-zidovudine-containing regimens). Median haemoglobin increased over time in both groups, with differences in haemoglobin response over time related to baseline haemoglobin levels and zidovudine use (p = 0.003). The groups of patients on zidovudine at the 10th and 90th percentiles had downward sloping curves while all other groups had upward trending haemoglobin levels. Although haemoglobin levels increased overall for patients on zidovudine-containing regimens, for those in the 10th and 90th percentiles haemoglobin levels trended downward over time. These results have implications for decisions regarding when to initiate, switch from or avoid the use of zidovudine.

  12. Hemoglobin recovery among HIV-1 infected patients on zidovudine-based antiretroviral therapy and other regimens in North-central Nigeria

    PubMed Central

    Parrish, Deidra D.; Blevins, Meridith; Megazzini, Karen M.; Shepherd, Bryan E.; Mohammed, Mukhtar Y.; Wester, C William; Vermund, Sten H.; Aliyu, Muktar H.

    2015-01-01

    Objective To assess trends in hemoglobin recovery among HIV-infected patients initiated on zidovudine-based combined antiretroviral therapy (cART) stratified by baseline hemoglobin level. Methods Hemoglobin data from non-pregnant adult patients initiating cART in rural north-central Nigeria between June 2009 and May 2011 was analyzed using a linear mixed effects model to assess the interaction between time, zidovudine-containing regimen, and baseline hemoglobin level on the outcome of subsequent hemoglobin level. Best fit curves were created for baseline hemoglobin in the 10th, 25th, 75th and 90th percentiles. Results We included 313 patients with 736 measures of hemoglobin in the analysis (239 on zidovudine and 74 on non-zidovudine-containing regimens). Median hemoglobin increased over time in both groups, with differences in hemoglobin response over time related to baseline hemoglobin levels and zidovudine use (p = 0.003). The groups of patients on zidovudine at the 10th and 90th percentiles had downward sloping curves while all other groups had upward trending hemoglobin levels. Conclusion Though hemoglobin levels increased overall for patients on zidovudine-containing regimens, for those in the 10th and 90th percentiles hemoglobin levels trended downward over time. These results have implications for decisions regarding when to initiate, switch from or avoid the use of zidovudine. PMID:24104694

  13. The emergence of drug resistant HIV variants and novel anti-retroviral therapy

    PubMed Central

    Paydary, Koosha; Khaghani, Parisa; Emamzadeh-Fard, Sahra; Alinaghi, Seyed Ahmad Seyed; Baesi, Kazem

    2013-01-01

    After its identification in 1980s, HIV has infected more than 30 million people worldwide. In the era of highly active anti-retroviral therapy, anti-retroviral drug resistance results from insufficient anti-retroviral pressure, which may lead to treatment failure. Preliminary studies support the idea that anti-retroviral drug resistance has evolved largely as a result of low-adherence of patients to therapy and extensive use of anti-retroviral drugs in the developed world; however, a highly heterogeneous horde of viral quasi-species are currently circulating in developing nations. Thus, the prioritizing of strategies adopted in such two worlds should be quite different considering the varying anti-retroviral drug resistance prevalence. In this article, we explore differences in anti-retroviral drug resistance patterns between developed and developing countries, as they represent two distinct ecological niches of HIV from an evolutionary standpoint. PMID:23835806

  14. Retrovirus XMRV Is Inhibited by Host Proteins and Anti-HIV Drugs AZT, Tenofovir, and Raltegravir | Center for Cancer Research

    Cancer.gov

    A newly discovered retrovirus, XMRV, isolated from prostate cancer tissues for the first time in 2006, has recently been reported in patients with this cancer, as well as in patients with chronic fatigue syndrome (CFS). However, five subsequent studies could not validate these reports. Since XMRV was isolated from the T and B cells of CFS patients, Vinay Pathak and his colleagues in the HIV Drug Resistance Program sought to determine how XMRV was countering intracellular defense mechanisms that inhibit retroviral replication in human cells.

  15. 'Click' chemistry synthesis and capillary electrophoresis study of 1,4-linked 1,2,3-triazole AZT-systemin conjugate.

    PubMed

    Dobkowski, Michał; Szychowska, Aleksandra; Pieszko, Małgorzata; Miszka, Anna; Wojciechowska, Monika; Alenowicz, Magdalena; Ruczyński, Jarosław; Rekowski, Piotr; Celewicz, Lech; Barciszewski, Jan; Mucha, Piotr

    2014-09-01

    The Cu(I) catalyzed Huisgen 1,3-dipolar azide-alkyne cycloaddition (CuAAC) was applied for a nucleoside-peptide bioconjugation. Systemin (Sys), an 18-aa plant signaling peptide naturally produced in response to wounding or pathogen attack, was chemically synthesized as its N-propynoic acid functionalized analog (Prp-Sys) using the SPPS. Next, CuAAC was applied to conjugate Prp-Sys with 3'-azido-2',3'-dideoxythymidine (AZT), a model cargo molecule. 1,4-Linked 1,2,3-triazole AZT-Sys conjugate was designed to characterize the spreading properties and ability to translocate of cargo molecules of systemin. CuAAC allowed the synthesis of the conjugate in a chemoselective and regioselective manner, with high purity and yield. The presence of Cu(I) ions generated in situ drove the CuAAC reaction to completion within a few minutes without any by-products. Under typical separation conditions of phosphate 'buffer' at low pH and uncoated fused bare-silica capillary, an increasing peak intensity assigned to triazole-linked AZT-Sys conjugate was observed using capillary electrophoresis (CE) during CuAAC. CE analysis showed that systemin peptides are stable in tomato leaf extract for up to a few hours. CE-ESI-MS revealed that the native Sys and its conjugate with AZT are translocated through the tomato stem and can be directly detected in stem exudates. The results show potential application of systemin as a transporter of low molecular weight cargo molecules in tomato plant and of CE method to characterize a behavior of plant peptides and its analogs.

  16. The engineered thymidylate kinase (TMPK)/AZT enzyme-prodrug axis offers efficient bystander cell killing for suicide gene therapy of cancer.

    PubMed

    Sato, Takeya; Neschadim, Anton; Lavie, Arnon; Yanagisawa, Teruyuki; Medin, Jeffrey A

    2013-01-01

    We previously described a novel suicide (or 'cell fate control') gene therapy enzyme/prodrug system based on an engineered variant of human thymidylate kinase (TMPK) that potentiates azidothymidine (AZT) activation. Delivery of a suicide gene sequence into tumors by lentiviral transduction embodies a cancer gene therapy that could employ bystander cell killing as a mechanism driving significant tumor regression in vivo. Here we present evidence of a significant bystander cell killing in vitro and in vivo mediated by the TMPK/AZT suicide gene axis that is reliant on the formation of functional gap-junctional intercellular communications (GJICs). Potentiation of AZT activation by the engineered TMPK expressed in the human prostate cancer cell line, PC-3, resulted in effective bystander killing of PC-3 cells lacking TMPK expression--an effect that could be blocked by the GJIC inhibitor, carbenoxolone. Although GJICs are mainly formed by connexins, a new family of GJIC molecules designated pannexins has been recently identified. PC-3 cells expressed both connexin43 (Cx43) and Pannexin1 (Panx1), but Panx1 expression predominated at the plasma membrane, whereas Cx43 expression was primarily localized to the cytosol. The contribution of bystander effects to the reduction of solid tumor xenografts established by the PC-3 cell line was evaluated in an animal model. We demonstrate the contribution of bystander cell killing to tumor regression in a xenograft model relying on the delivery of expression of the TMPK suicide gene into tumors via direct intratumoral injection of recombinant therapeutic lentivirus. Taken together, our data underscore that the TMPK/AZT enzyme-prodrug axis can be effectively utilized in suicide gene therapy of solid tumors, wherein significant tumor regression can be achieved via bystander effects mediated by GJICs.

  17. Effect of the HIV nucleoside reverse transcriptase inhibitor zidovudine on the growth and differentiation of primary gingival epithelium.

    PubMed

    Mitchell, D; Israr, M; Alam, S; Kishel, J; Dinello, D; Meyers, C

    2012-05-01

    Oral complications associated with HIV infection and with the antiretroviral drugs used to treat it are of increasing concern in HIV-infected patients. Protease inhibitors have been shown to change the proliferation and differentiation state of oral tissues but the effect of nucleoside reverse transcriptase inhibitors is currently unknown. This study examined the effect of zidovudine on the growth and differentiation of the gingival epithelium. Gingival keratinocyte organotypic (raft) cultures were established. The raft cultures were treated with a range of zidovudine concentrations. Haematoxylin and eosin staining was performed to examine the effect of zidovudine on gingival epithelium growth and stratification. Raft cultures were immunohistochemically analysed to determine the effect of this drug on the expression of key differentiation and proliferation markers, including cytokeratins and proliferating cell nuclear antigen (PCNA). Zidovudine dramatically changed the proliferation and differentiation state of gingival tissues both when it was present throughout the growth period of the tissue and when it was added to established tissue at day 8. Zidovudine treatment increased the expression of cytokeratin 10, PCNA and cyclin A. Conversely, cytokeratin 5, involucrin and cytokeratin 6 expression was decreased. The tissue exhibited characteristics of increased proliferation in the suprabasal layers as well as an increased fragility and an inability to heal itself. Zidovudine treatment, even when applied at low concentrations for short periods of time, deregulated the cell cycle/proliferation and differentiation pathways, resulting in abnormal epithelial repair and proliferation. Our system could potentially be developed as a model for studying the effects of HIV and highly active antiretroviral therapy in vitro. © 2012 British HIV Association.

  18. Toxicity and clinical outcomes in patients with HIV on zidovudine and tenofovir based regimens: a retrospective cohort study.

    PubMed

    Thuppal, Sowmyanarayanan V; Wanke, Christine A; Noubary, Farzad; Cohen, Joshua T; Mwamburi, Mkaya; Ooriapdickal, Abraham C; Muliyil, Jayaprakash; Kang, Gagandeep; Varghese, George M; Rupali, Priscilla; Karthik, Rajiv; Sathasivam, Rajkumar; Clarance, Peace; Pulimood, Susanne A; Peter, Dincy; George, Leni

    2015-06-01

    Adverse drug reactions are a major concern with zidovudine/stavudine treatment regimens. The less toxic tenofovir regimen is an alternative, but is seldom considered due to the higher costs. This study compared adverse drug reactions and other clinical outcomes resulting from the use of these two treatment regimens in India. Baseline, clinical characteristics and follow-up outcomes were collected by chart reviews of HIV-positive adults and compared using univariate/multivariate analysis, with and without propensity score adjustments. Data were collected from 129 and 92 patients on zidovudine (with lamivudine and nevirapine) and tenofovir (with emtricitabine and efavirenz) regimens, respectively. Compared to patients receiving the zidovudine regimen, patients receiving the tenofovir regimen had fewer adverse drug reactions (47%, 61/129 vs 11%, 10/92; p<0.01), requiring fewer regimen changes (36%, 47/129 vs 3%, 3/92; p0.01). With the propensity score, the zidovudine regimen had 8 times more adverse drug reactions (p<0.01). Opportunistic infections were similar between regimens without propensity score, while the zidovudine regimen had 1.2 times (p=0.63) more opportunistic infections with propensity score. Patients on the tenofovir regimen gained more weight. Increase in CD4 levels and treatment adherence (>95%) was similar across regimens. Patients on a tenofovir regimen have better clinical outcomes and improved general health than patients on the zidovudine regimen. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Foetal loss and enhanced fertility observed in mice treated with Zidovudine or Nevirapine.

    PubMed

    Onwuamah, Chika K; Ezechi, Oliver C; Herbertson, Ebiere C; Audu, Rosemary A; Ujah, Innocent A O; Odeigah, Peter G C

    2014-01-01

    Health concerns for HIV-infected persons on antiretroviral therapy (ART) have moved from morbidity to the challenges of long-term ART. We investigated the effect of Zidovudine or Nevirapine on reproductive capacity across two mouse generations. A prospective mouse study with drugs administered through one spermatogenic cycle. Mouse groups (16 males and 10 females) were given Zidovudine or Nevirapine for 56 days. Males were mated to untreated virgin females to determine dominant lethal effects. Twenty females (10 treated and 10 untreated) mated with the treated males per dose and gave birth to the F1 generation. Parental mice were withdrawn from drugs for one spermatogenic cycle and mated to the same dams to ascertain if effects are reversible. The F1 generation were exposed for another 56 days and mated to produce the F2 generation. Foetal loss was indicated in the dominant lethal assay as early as four weeks into drug administration to the males. At the first mating of the parental generation to produce the F1 generation, births from 10 dams/dose when the 'father-only' was exposed to Zidovudine (10, 100 and 250 mg/kg) was 3, 2 and 1 while it was 7, 1 and 4 respectively when 'both-parents' were exposed. Similarly births from the parental generation first mating when the 'father-only' was exposed to Nevirapine (5, 50 and 150 mg/kg) was 2, 2 and 0 while it was 6, 5 and 9 respectively when 'both-parents' were exposed. However, fertility was not significantly different neither by dose nor by the parental exposure. The F1 mice mated to produce the F2 generation recorded only one birth. The dominant lethal analysis showed foetal loss occurred when the "fathers-only" were treated while fertility was enhanced when "both-parents" were on therapy at the time of mating.

  20. Foetal Loss and Enhanced Fertility Observed in Mice Treated with Zidovudine or Nevirapine

    PubMed Central

    Onwuamah, Chika K.; Ezechi, Oliver C.; Herbertson, Ebiere C.; Audu, Rosemary A.; Ujah, Innocent A. O.; Odeigah, Peter G. C.

    2014-01-01

    Background Health concerns for HIV-infected persons on antiretroviral therapy (ART) have moved from morbidity to the challenges of long-term ART. We investigated the effect of Zidovudine or Nevirapine on reproductive capacity across two mouse generations. Methods A prospective mouse study with drugs administered through one spermatogenic cycle. Mouse groups (16 males and 10 females) were given Zidovudine or Nevirapine for 56 days. Males were mated to untreated virgin females to determine dominant lethal effects. Twenty females (10 treated and 10 untreated) mated with the treated males per dose and gave birth to the F1 generation. Parental mice were withdrawn from drugs for one spermatogenic cycle and mated to the same dams to ascertain if effects are reversible. The F1 generation were exposed for another 56 days and mated to produce the F2 generation. Results Foetal loss was indicated in the dominant lethal assay as early as four weeks into drug administration to the males. At the first mating of the parental generation to produce the F1 generation, births from 10 dams/dose when the ‘father-only’ was exposed to Zidovudine (10, 100 and 250 mg/kg) was 3, 2 and 1 while it was 7, 1 and 4 respectively when ‘both-parents’ were exposed. Similarly births from the parental generation first mating when the ‘father-only’ was exposed to Nevirapine (5, 50 and 150 mg/kg) was 2, 2 and 0 while it was 6, 5 and 9 respectively when ‘both-parents’ were exposed. However, fertility was not significantly different neither by dose nor by the parental exposure. The F1 mice mated to produce the F2 generation recorded only one birth. Conclusion The dominant lethal analysis showed foetal loss occurred when the “fathers-only” were treated while fertility was enhanced when “both-parents” were on therapy at the time of mating. PMID:25233270

  1. Design and in vitro evaluation of zidovudine oral controlled release tablets prepared using hydroxypropyl methylcellulose.

    PubMed

    Ravi, Punna Rao; Ganga, Sindhura; Saha, Ranendra Narayan

    2008-04-01

    Oral controlled release matrix tablets of zidovudine were prepared using different proportions and different viscosity grades of hydroxypropyl methylcellulose. The effect of various formulation factors like polymer proportion, polymer viscosity and compression force on the in vitro release of drug were studied. In vitro release studies were carried out using United States Pharmacopeia (USP) type 1 apparatus (basket method) in 900 ml of pH 6.8 phosphate buffer at 100 rpm. The release kinetics were analyzed using Zero-order model equation, Higuchi's square-root equation and Ritger-Peppas' empirical equation. Compatibility of drug with various formulations excipients used was studied. In vitro release studies revealed that the release rate decreased with increase in polymer proportion and viscosity grade. Increase in compression force was found to decrease the rate of drug release. Matrix tablets containing 10% hydroxypropyl methylcellulose (HPMC) 4000 cps were found to show a good initial drug release of 21% in the first hour and extended the release upto 16 h. Matrix tablets containing 20% HPMC 4000 cps and 10% HPMC 15000 cps showed a first hour release of 18% and extended the release upto 20 h. Mathematical analysis of the release kinetics indicated that the nature of drug release from the matrix tablets followed non-Fickian or anomalous release. No incompatibility was observed between the drug and excipients used in the formulation of matrix tablets. The developed controlled release matrix tablets of zidovudine, with good initial release (17-25% in first hour) and which extend the release upto 16-20 h, can overcome the disadvantages of conventional tablets of zidovudine.

  2. Pharmacokinetics of Zidovudine Dosed Twice Daily According to World Health Organization Weight Bands in Ugandan HIV-infected Children

    PubMed Central

    2014-01-01

    Data on zidovudine pharmacokinetics in children dosed using World Health Organization weight bands are limited. About 45 HIV-infected, Ugandan children, 3.4 (2.6–6.2) years, had intensive pharmacokinetic sampling. Geometric mean zidovudine AUC0–12h was 3.0 h.mg/L, which is higher than previously observed in adults, and was independently higher in those receiving higher doses, younger and underweight children. Higher exposure was also marginally associated with lower hemoglobin. PMID:24736440

  3. Resistance detected by pyrosequencing following zidovudine-monotherapy for prevention of HIV-1 mother-to-child-transmission

    PubMed Central

    Olson, Scott C.; Ngo-Giang-Huong, Nicole; Beck, Ingrid; Deng, Wenjie; Britto, Paula; Shapiro, David E.; Bumgarner, Roger E.; Mullins, James I.; Van Dyke, Russell B.; Jourdain, Gonzague; Frenkel, Lisa M.

    2015-01-01

    To prevent mother-to-child-transmission-of-HIV-1, the 2010 WHO guidelines recommended prenatal zidovudine monotherapy (Option A). To determine if ZDV-monotherapy selects for HIV-resistance in antiretroviral-naïve women during pregnancy, specimens from 50 were examined using pyrosequencing. ZDV-resistance mutations were detected at delivery in 7 (14%, 95% confidence interval 6.6-26.5%). These data raise the question whether women administered zidovudine monotherapy for PMTCT could have higher risk of virologic failure when later started on combination ARV therapy, as has been demonstrated following single-dose-nevirapine prophylaxis. PMID:26244386

  4. Human immunodeficiency virus fitness in vivo: calculations based on a single zidovudine resistance mutation at codon 215 of reverse transcriptase.

    PubMed

    Goudsmit, J; De Ronde, A; Ho, D D; Perelson, A S

    1996-08-01

    We monitored a subject newly infected with a zidovudine-resistant human immunodeficiency virus type 1 strain and found that in the absence of drug, the viral population with the resistance-conferring tyrosine (TAC) codon 215 of reverse transcriptase was gradually replaced. By using standard formulas to model the effects of selection at a single locus in an asexual haploid population, the relative fitness gain of the viral population with a single mutation at codon 215 creating a serine (TCC) was calculated. We concluded that a viral population with a serine at reverse transcriptase codon 215 conferring zidovudine sensitivity was between 0.4 and 2.3% more fit.

  5. Retroviral restriction and dependency factors in primates and carnivores

    PubMed Central

    Fadel, Hind J.; Poeschla, Eric M.

    2014-01-01

    Recent studies have extended the rapidly developing retroviral restriction factor field to cells of carnivore species. Carnivoran genomes, and the domestic cat genome in particular, are revealing intriguing properties vis-à;-vis the primate and feline lentiviruses, not only with respect to their repertoires of virus-blocking restriction factors but also replication-enabling dependency factors. Therapeutic application of restriction factors is envisioned for human immunodeficiency virus (HIV) disease and the feline immunodeficiency virus (FIV) model has promise for testing important hypotheses at the basic and translational level. Feline cell-tropic HIV-1 clones have also been generated by a strategy of restriction factor evasion. We review progress in this area in the context of what is known about retroviral restriction factors such as TRIM5alpha, TRIMCyp, APOBEC3 proteins and BST-2/Tetherin. PMID:21715018

  6. Retroviral restriction and dependency factors in primates and carnivores.

    PubMed

    Fadel, Hind J; Poeschla, Eric M

    2011-10-15

    Recent studies have extended the rapidly developing retroviral restriction factor field to cells of carnivore species. Carnivoran genomes, and the domestic cat genome in particular, are revealing intriguing properties vis-à-vis the primate and feline lentiviruses, not only with respect to their repertoires of virus-blocking restriction factors but also replication-enabling dependency factors. Therapeutic application of restriction factors is envisioned for human immunodeficiency virus (HIV) disease and the feline immunodeficiency virus (FIV) model has promise for testing important hypotheses at the basic and translational level. Feline cell-tropic HIV-1 clones have also been generated by a strategy of restriction factor evasion. We review progress in this area in the context of what is known about retroviral restriction factors such as TRIM5α, TRIMCyp, APOBEC3 proteins and BST-2/Tetherin.

  7. Convergent capture of retroviral superantigens by mammalian herpesviruses

    PubMed Central

    Aswad, Amr; Katzourakis, Aris

    2015-01-01

    Horizontal gene transfer from retroviruses to mammals is well documented and extensive, but is rare between unrelated viruses with distinct genome types. Three herpesviruses encode a gene with similarity to a retroviral superantigen gene (sag) of the unrelated mouse mammary tumour virus (MMTV). We uncover ancient retroviral sags in over 20 mammals to reconstruct their shared history with herpesviral sags, revealing that the acquisition is a convergent evolutionary event. A retrovirus circulating in South American primates over 10 million years ago was the source of sag in two monkey herpesviruses, and a different retrovirus was the source of sag in a Peruvian rodent herpesvirus. We further show through a timescaled phylogenetic analysis that a cross-species transmission of monkey herpesviruses occurred after the acquisition of sag. These results reveal that a diverse range of ancient sag-containing retroviruses independently donated sag twice from two separate lineages that are distinct from MMTV. PMID:26400439

  8. Intrinsic retroviral reactivation in human preimplantation embryos and pluripotent cells

    PubMed Central

    Grow, Edward J.; Flynn, Ryan A.; Chavez, Shawn L.; Bayless, Nicholas L.; Wossidlo, Mark; Wesche, Daniel; Martin, Lance; Ware, Carol; Blish, Catherine A.; Chang, Howard Y.; Reijo Pera, Renee A.; Wysocka, Joanna

    2015-01-01

    Summary Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections, which comprise nearly 8% of the human genome1. The most recently acquired human ERV is HERV-K (HML-2), which repeatedly infected the primate lineage both before and after the divergence of humans and chimpanzees2,3. Unlike most other human ERVs, HERV-K retained multiple copies of intact open reading frames (ORFs) encoding retroviral proteins4. However, HERV-K is transcriptionally silenced by the host with exception of certain pathological contexts, such as germ cell tumors, melanoma, or HIV infection5–7. Here we demonstrate that DNA hypomethylation at LTR elements representing the most recent genomic integrations, together with transactivation by OCT4, synergistically facilitate HERV-K expression. Consequently, HERV-K is transcribed during normal human embryogenesis beginning with embryonic genome activation (EGA) at the 8-cell stage, continuing through the emergence of epiblast cells in pre-implantation blastocysts, and ceasing during hESC derivation from blastocyst outgrowths. Remarkably, HERV-K viral-like particles and Gag proteins are detected in human blastocysts, indicating that early human development proceeds in the presence of retroviral products. We further show that overexpression of one such product, HERV-K accessory protein Rec, in a pluripotent cell line is sufficient to increase IFITM1 levels on the cell surface and inhibit viral infection, suggesting at least one mechanism through which HERV-K can induce viral restriction pathways in early embryonic cells. Moreover, Rec directly binds a subset of cellular RNAs and modulates their ribosome occupancy, arguing that complex interactions between retroviral proteins and host factors can fine-tune regulatory properties of early human development. PMID:25896322

  9. Retroviral vector production under serum deprivation: The role of lipids.

    PubMed

    Rodrigues, A F; Carmo, M; Alves, P M; Coroadinha, A S

    2009-12-15

    The use of retroviral vectors for gene therapy applications demands high titer preparations and stringent quality standards. However, the manufacturing of these vectors still represents a highly challenging task due to the low productivity of the cell lines and reduced stability of the vector infectivity, particularly under serum-free conditions. With the objective of understanding the major limitations of retroviral vector production under serum deprivation, a thorough study of viral production kinetics, vector characterization and cell growth and metabolic behavior was conducted, for 293 FLEX 18 and Te Fly Ga 18 producer cell lines using different serum concentrations. The reduction of serum supplementation in the culture medium resulted in pronounced decreases in cell productivity of infectious vector, up to ninefold in 293 FLEX 18 cells and sevenfold in Te Fly Ga 18 cells. Total particles productivity was maintained, as assessed by measuring viral RNA; therefore, the decrease in infectious vector production could be attributed to higher defective particles output. The absence of the serum lipid fraction was found to be the major cause for this decrease in cell viral productivity. The use of delipidated serum confirmed the requirement of serum lipids, particularly cholesterol, as its supplementation not only allowed the total recovery of viral titers as well as additional production increments in both cell lines when comparing with the standard 10% (v/v) FBS supplementation. This work identified lower production ratios of infectious particles/total particles as the main restraint of retroviral vector production under serum deprivation; this is of the utmost importance concerning the clinical efficacy of the viral preparations. Lipids were confirmed as the key serum component correlated with the production of infective retroviral vectors and this knowledge can be used to efficiently design medium supplementation strategies for serum-free production. Biotechnol

  10. Genetic reshuffling reconstitutes functional expression cassettes in retroviral vectors.

    PubMed

    Tabotta, W; Klein, D; Hohenadl, C; Salmons, B; Günzburg, W H

    2001-01-01

    A major prerequisite for the design of retroviral vectors encoding cell toxic or harmful genes is the possibility to tightly control gene expression, thus limiting activity to the relevant target cells and protecting the packaging cell used for production of recombinant viral particles. In the present study a system was developed in which genetic reshuffling during the retroviral life cycle is exploited, allowing reconstitution of functional expression cassettes from separate elements exclusively in transduced target cells. For construction of these murine leukaemia virus (MLV)-based reconstituting viral vectors (ReCon), a promoterless inverted enhanced green fluorescent protein (EGFP) reporter gene cassette was inserted in place of the U3 region of the 3' LTR. Subsequently, the human ubiquitin promoter was inserted in the inverse orientation into the R/U5 border of the 5' LTR of the vector. PA317 packaging cells stably transfected with ReCon vectors were established and EGFP expression was analysed by fluorescence-activated cell sorting (FACS). After detection of low-level background expression, an additional polyadenylation signal was introduced in antisense orientation into the 3' LTR at the R/U5 border to prevent accidental read-through transcription from neighbouring cellular promoters. Virus-containing cell culture supernatants were then used to infect NIH3T3 target cells. EGFP expression, recloning and sequencing of integrated proviruses demonstrated the correct reassembly of the transduced ubiquitin/EGFP transcription unit in these infected cells. This facile and convenient system should allow production of retroviral vectors encoding potentially toxic proteins, cell cycle inhibitors or inducers of apoptosis, all of which would interfere with vector production if expressed in the retroviral packaging cell.

  11. Retroviral Infections in Peruvian Men Who Have Sex With Men

    PubMed Central

    La Rosa, Alberto M.; Zunt, Joseph R.; Peinado, Jesus; Lama, Javier R.; Ton, Thanh G.N.; Suarez, Luis; Pun, Monica; Cabezas, Cesar; Sanchez, Jorge

    2009-01-01

    We tested 2,655 Peruvian MSM for retroviral infection: HTLV-1 was detected in 48 (1.8%), HTLV-2 in 28 (1.1%), and HTLV-1 and -2 in 5 (0.2%); HIV infection was detected in 329 (12.4 %); 24 (7.3%) were coinfected with HTLV. Risk factors for HTLV-1 and -2 varied with sexual role. PMID:19480577

  12. Deciphering the Code for Retroviral Integration Target Site Selection

    PubMed Central

    Santoni, Federico Andrea; Hartley, Oliver; Luban, Jeremy

    2010-01-01

    Upon cell invasion, retroviruses generate a DNA copy of their RNA genome and integrate retroviral cDNA within host chromosomal DNA. Integration occurs throughout the host cell genome, but target site selection is not random. Each subgroup of retrovirus is distinguished from the others by attraction to particular features on chromosomes. Despite extensive efforts to identify host factors that interact with retrovirion components or chromosome features predictive of integration, little is known about how integration sites are selected. We attempted to identify markers predictive of retroviral integration by exploiting Precision-Recall methods for extracting information from highly skewed datasets to derive robust and discriminating measures of association. ChIPSeq datasets for more than 60 factors were compared with 14 retroviral integration datasets. When compared with MLV, PERV or XMRV integration sites, strong association was observed with STAT1, acetylation of H3 and H4 at several positions, and methylation of H2AZ, H3K4, and K9. By combining peaks from ChIPSeq datasets, a supermarker was identified that localized within 2 kB of 75% of MLV proviruses and detected differences in integration preferences among different cell types. The supermarker predicted the likelihood of integration within specific chromosomal regions in a cell-type specific manner, yielding probabilities for integration into proto-oncogene LMO2 identical to experimentally determined values. The supermarker thus identifies chromosomal features highly favored for retroviral integration, provides clues to the mechanism by which retrovirus integration sites are selected, and offers a tool for predicting cell-type specific proto-oncogene activation by retroviruses. PMID:21124862

  13. Adherence to combined Lamivudine + Zidovudine versus individual components: a community-based retrospective medicaid claims analysis.

    PubMed

    Legorreta, A; Yu, A; Chernicoff, H; Gilmore, A; Jordan, J; Rosenzweig, J C

    2005-11-01

    Adherence to a fixed dose combination of dual nucleoside antiretroviral therapy was compared between human immunodeficiency virus (HIV)-infected patients newly started on a fixed dosed combination of lamivudine (3TC) 150 mg/zidovudine (ZDV) 300 mg versus its components taken as separate pills. Medicaid pharmacy claims data were used for analyses. To examine the association between treatment group and medication adherence, three types of multivariate regressions were employed. In addition, all regressions were conducted for the whole population using data from 1995 to 2001 as well as a subpopulation, which excluded data prior to September 1997. Model covariates included patient characteristics, healthcare utilization, and non-study antiretroviral therapy use. The likelihood of > or =95% adherence among patients on combination therapy was three times greater than patients taking 3TC and ZDV in separate pills. Also, combination therapy patients had on average 1.4 fewer adherence failures per year of follow-up and nearly double the time to adherence failure compared to the separate pills group. Consistency among study results suggests that fixed dose combination therapies such as lamivudine (3TC) 150 mg/ zidovudine (ZDV) 300 mg should be considered when prescribing HIV treatment that includes an appropriate dual nucleoside.

  14. Retroviral integrase protein and intasome nucleoprotein complex structures

    PubMed Central

    Grawenhoff, Julia; Engelman, Alan N

    2017-01-01

    Retroviral replication proceeds through the integration of a DNA copy of the viral RNA genome into the host cellular genome, a process that is mediated by the viral integrase (IN) protein. IN catalyzes two distinct chemical reactions: 3’-processing, whereby the viral DNA is recessed by a di- or trinucleotide at its 3’-ends, and strand transfer, in which the processed viral DNA ends are inserted into host chromosomal DNA. Although IN has been studied as a recombinant protein since the 1980s, detailed structural understanding of its catalytic functions awaited high resolution structures of functional IN-DNA complexes or intasomes, initially obtained in 2010 for the spumavirus prototype foamy virus (PFV). Since then, two additional retroviral intasome structures, from the α-retrovirus Rous sarcoma virus (RSV) and β-retrovirus mouse mammary tumor virus (MMTV), have emerged. Here, we briefly review the history of IN structural biology prior to the intasome era, and then compare the intasome structures of PFV, MMTV and RSV in detail. Whereas the PFV intasome is characterized by a tetrameric assembly of IN around the viral DNA ends, the newer structures harbor octameric IN assemblies. Although the higher order architectures of MMTV and RSV intasomes differ from that of the PFV intasome, they possess remarkably similar intasomal core structures. Thus, retroviral integration machineries have adapted evolutionarily to utilize disparate IN elements to construct convergent intasome core structures for catalytic function. PMID:28289517

  15. Retroviral Vectors: Post Entry Events and Genomic Alterations

    PubMed Central

    Nowrouzi, Ali; Glimm, Hanno; von Kalle, Christof; Schmidt, Manfred

    2011-01-01

    The curative potential of retroviral vectors for somatic gene therapy has been demonstrated impressively in several clinical trials leading to sustained long-term correction of the underlying genetic defect. Preclinical studies and clinical monitoring of gene modified hematopoietic stem and progenitor cells in patients have shown that biologically relevant vector induced side effects, ranging from in vitro immortalization to clonal dominance and oncogenesis in vivo, accompany therapeutic efficiency of integrating retroviral gene transfer systems. Most importantly, it has been demonstrated that the genotoxic potential is not identical among all retroviral vector systems designed for clinical application. Large scale viral integration site determination has uncovered significant differences in the target site selection of retrovirus subfamilies influencing the propensity for inducing genetic alterations in the host genome. In this review we will summarize recent insights gained on the mechanisms of insertional mutagenesis based on intrinsic target site selection of different retrovirus families. We will also discuss examples of side effects occurring in ongoing human gene therapy trials and future prospectives in the field. PMID:21994741

  16. The changes in bone organic and inorganic matrix in newborn rats after maternal application of antiretroviral agents: Indinavir and zidovudine.

    PubMed

    Maciejewska, Karina; Drzazga, Zofia; Kaszuba, Michal

    2015-05-06

    This work presents results concerning influence of indinavir (protease inhibitor, PI(1)) and zidovudine (nucleoside and nucleotide inhibitor of reverse transcriptase, NRTI) administered to pregnant Wistar rat females on organic and mineral constituents of bones and teeth (mandibles, skulls, tibiae, femurs, and incisors) of their offspring at the age of: 7, 14, and 28 days studied by means of induced laser and X-ray fluorescence spectroscopy supported by digital radiography. Influence of indinavir administered to pregnant female rats on bone of their offspring revealed mainly in changes of mineral concentration: lowered Ca concentration and disturbances of trace elements. Zidovudine influenced organic matter more than inorganic matrix which was seen in enhancement of LIF fluorescence. However, there was also an unexpected increase of bone density for rats from zidovudine group, unlike indinavir group, observed. Our studies suggest that studied antiretroviral agents given to pregnant women, may have different destructive impact on bone state of their offspring in the first period of life. Maternal administration of zidovudine may delay development of organic matrix, while indinavir may have adverse effects on inorganic structure.

  17. Genotoxic signature in cord blood cells of newborns exposed in utero to a Zidovudine-based antiretroviral combination.

    PubMed

    André-Schmutz, Isabelle; Dal-Cortivo, Liliane; Six, Emmanuelle; Kaltenbach, Sophie; Cocchiarella, Fabienne; Le Chenadec, Jerome; Cagnard, Nicolas; Cordier, Anne-Gael; Benachi, Alexandra; Mandelbrot, Laurent; Azria, Elie; Bouallag, Naima; Luce, Sonia; Ternaux, Brigitte; Reimann, Christian; Revy, Patrick; Radford-Weiss, Isabelle; Leschi, Cristina; Recchia, Alessandra; Mavilio, Fulvio; Cavazzana, Marina; Blanche, Stéphane

    2013-07-15

    The genotoxicity of zidovudine has been established in experimental models. The objective of the study was to identify genotoxicity markers in cord blood cells from newborns exposed in utero to antiretroviral (ARV) combinations containing zidovudine. Cells were investigated by karyotyping and gene expression analysis of the CD34(+) hematopoietic stem/progenitor cell (HPC) compartment. Karyotyping of the cord blood cells from 15 ARV-exposed newborns and 12 controls revealed a higher proportion of aneuploid cells in the exposed group (median, 18.8% [interquartile range, 10.0%-26.7%] vs 6.6% [interquartile range, 3.1%-11.7%]; P < .001). All chromosomes were involved, with a random distribution of these alterations. Gene expression profiling of CD34(+) HPCs from 7 ARV-exposed and 6 control newborns revealed that >300 genes were significantly upregulated or downregulated by at least 1.5-fold in the exposed group (P < .05 for all comparisons). Significant alterations of genes involved in cell cycle control, mitotic checkpoints, and DNA repair were identified. Although this study does not allow discrimination between the roles of each of the 3 drugs, both cytogenetic and transcriptional findings are similar to those in cellular experiments that used zidovudine alone. The cord blood cells, including hematopoietic stem cells, from newborns exposed in utero to a zidovudine-based ARV combination present cytogenetic and transcriptional abnormalities compatible with DNA damage.

  18. Metabolic syndrome in patients on first-line antiretroviral therapy containing zidovudine or tenofovir in rural Lesotho, Southern Africa.

    PubMed

    Labhardt, Niklaus Daniel; Müller, Urs Franz; Ringera, Isaac; Ehmer, Jochen; Motlatsi, Mokete M; Pfeiffer, Karolin; Hobbins, Michael A; Muhairwe, Josephine A; Muser, Juergen; Hatz, Christoph

    2017-06-01

    To assess the prevalence of metabolic syndrome (MetS) among patients in rural Lesotho who are taking first-line antiretroviral therapy (ART) containing either zidovudine or tenofovir disoproxil. Cross-sectional survey in 10 facilities in Lesotho among adult (≥16 years) patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line ART for ≥6 months. MetS was defined according to the International Diabetes Federation criteria. Among 1166 patients (65.8% female), 22.2% (95% CI: 19.3-25.3) of women and 6.3% (4.1-9.1) of men met the IDF definition of MetS (P < 0.001). In both sexes, there was no significant difference in MetS prevalence between NNRTIs. However, in women taking zidovudine as nucleoside reverse transcriptase inhibitor (NRTI), MetS prevalence was 27.9%, vs. 18.8% in those taking tenofovir. In the multivariate logistic regression allowing for socio-demographic and clinical covariates, ART containing zidovudine was associated with MetS in women (aOR 2.17 (1.46-3.22), P < 0.001) but not in men. In this study, taking ART containing zidovudine instead of tenofovir disoproxil was an independent predictor of MetS in women but not in men. This finding endorses WHO's recommendation of tenofovir as preferred NRTI. © 2017 John Wiley & Sons Ltd.

  19. Hepatoprotective role of neutrosecR on hepatic damage induced by combination of zidovudine and combined anti-tuberculous agents in rats.

    PubMed

    Awodele, Olufunsho; Agbaje, Esther O; Adesina, Enitan A; Akintonwa, Alade

    2011-07-20

    Advent of the HIV/AIDS pandemic has led to a dramatic increase in the number of TB cases worldwide. Availability of highly active antiretroviral therapy (HAART) has significantly improved the outcome of HIV/AIDS, in terms of prevention of opportunistic infections (OIs) as well as mortality however; liver toxicity is one of the most relevant adverse effects of antiretroviral therapy (ART). In view of the inevitable use of zidovudine (a common ART) and antituberculous fixed-dose combination therapy (FDCs) in the management of HIV-TB co-infection and the resultant hepatotoxicity, this study was aimed to investigate the hepatoprotective role of neutrosec (a combination of aminoacid and vitamins) on the hepatotoxicity induced by co-administration of zidovudine and combined fixed dose antituberculous agents. Twenty four rats were randomly allotted to four groups, consisting of the control, zidovudine plus fixed dose combined anti TB agents treated group, zidovudine plus fixed dose combined anti TB agents plus neutrosec treated group and neutrosec alone treated group. Therapeutic doses of zidovudine (8.5 mg/kg/day), fixed dose combined anti TB agents (25 mg/kg/day) and neutrosec (0.4 ml/kg/day) were administered to the animals via oral gavage, daily over 60 days. After 60 days, rats were sacrificed for internal macroscopic and histological examination of the liver. The liver enzyme parameters (AST, ALP, Total bilirubin, Total protein, Albumin) were determined using fully automated clinical chemistry analyzer (Hitachi 912, Boehringer Mannheim, Germany). Antioxidant enzymes activity and lipid peroxidation were determined according to standard procedures. The AST results showed a significant (p ≤ 0.05) decreased in the zidovudine plus anti-TB plus neutrosec treated group (125.50 ± 22.71) compared with zidovudine plus anti-TB treated group (399. 10 ± 0.45). It further showed non-significant decreased (p ≥ 0.05) in the ALP levels between the zidovudine plus anti TB

  20. Proteochemometrics mapping of the interaction space for retroviral proteases and their substrates.

    PubMed

    Kontijevskis, Aleksejs; Petrovska, Ramona; Yahorava, Sviatlana; Komorowski, Jan; Wikberg, Jarl E S

    2009-07-15

    Understanding the complex interactions of retroviral proteases with their ligands is an important scientific challenge in efforts to achieve control of retroviral infections. Development of drug resistance because of high mutation rates and extensive polymorphisms causes major problems in treating the deadly diseases these viruses cause, and prompts efforts to identify new strategies. Here we report a comprehensive analysis of the interaction of 63 retroviral proteases from nine different viral species with their substrates and inhibitors based on publicly available data from the past 17years of retroviral research. By correlating physico-chemical descriptions of retroviral proteases and substrates to their biological activities we constructed a highly statistically valid 'proteochemometric' model for the interactome of retroviral proteases. Analysis of the model indicated amino acid positions in retroviral proteases with the highest influence on ligand activity and revealed general physicochemical properties essential for tight binding of substrates across multiple retroviral proteases. Hexapeptide inhibitors developed based on the discovered general properties effectively inhibited HIV-1 proteases in vitro, and some exhibited uniformly high inhibitory activity against all HIV-1 proteases mutants evaluated. A generalized proteochemometric model for retroviral proteases interactome has been created and analysed in this study. Our results demonstrate the feasibility of using the developed general strategy in the design of inhibitory peptides that can potentially serve as templates for drug resistance-improved HIV retardants.

  1. Efficient conditional gene expression following transplantation of retrovirally transduced bone marrow stem cells.

    PubMed

    Chung, Jie-Yu; Mackay, Fabienne; Alderuccio, Frank

    2015-01-01

    Retroviral gene therapy combined with bone marrow stem cell transplantation can be used to generate mice with ectopic gene expression in the bone marrow compartment in a quick and cost effective manner when compared to generating and maintaining transgenic mouse lines. However a limitation of this procedure is the lack of cell specificity in gene expression that is associated with the use of endogenous retroviral promoters. Restricting gene expression to specific cell subsets utilising tissue-specific promoter driven retroviral vectors is a challenge. Here we describe the generation of conditional expression of retrovirally encoded genes in specific bone marrow derived cell lineages utilising a Cre-dependent retroviral vector. By utilising Lck and CD19 restricted Cre transgenic bone marrow stem cells, we generate chimeric animals with T or B lymphocyte restricted gene expression respectively. The design of the Cre-dependent retroviral vector enables expression of encoded MOG and GFP genes only in association with Cre mediated DNA inversion. Importantly this strategy does not significantly increase the size of the retroviral vector; as such we are able to generate bone marrow chimeric animals with significantly higher chimerism levels than previous studies utilising Cre-dependent retroviral vectors and Cre transgenic bone marrow stem cells. This demonstrates that the use of Cre-dependent retroviral vectors is able to yield high chimerism levels for experimental use and represent a viable alternative to generating transgenic animals. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Most Retroviral Recombinations Occur during Minus-Strand DNA Synthesis

    PubMed Central

    Zhang, Jiayou; Tang, Ling-Yun; Li, Ting; Ma, Yan; Sapp, Christy M.

    2000-01-01

    Retroviral RNA molecules are plus, or sense in polarity, equivalent to mRNA. During reverse transcription, the first strand of the DNA molecule synthesized is minus-strand DNA. After the minus strand is polymerized, the plus-strand DNA is synthesized using the minus-strand DNA as the template. In this study, a helper cell line that contains two proviruses with two different mutated gfp genes was constructed. Recombination between the two frameshift mutant genes resulted in a functional gfp. If recombination occurs during minus-strand DNA synthesis, the plus-strand DNA will also contain the functional sequence. After the cell divides, all of its offspring will be green. However, if recombination occurs during plus-strand DNA synthesis, then only the plus-strand DNA will contain the wild-type gfp sequence and the minus-strand DNA will still carry the frameshift mutation. The double-stranded DNA containing this mismatch was subsequently integrated into the host chromosomal DNA of D17 cells, which were unable to repair the majority of mismatches within the retroviral double-strand DNA. After the cell divided, one daughter cell contained the wild-type gfp sequence and the other daughter cell contained the frameshift mutation in the gfp sequence. Under fluorescence microscopy, half the cells in the offspring were green and the other half of the cells were colorless or clear. Thus, we demonstrated that more than 98%, if not all, retroviral recombinations occurred during minus-strand DNA synthesis. PMID:10666262

  3. Microbead-assisted retroviral transduction for clinical application.

    PubMed

    Heemskerk, Bianca; Jorritsma, Annelies; Gomez-Eerland, Raquel; Toebes, Mireille; Haanen, John B A G; Schumacher, Ton N M

    2010-10-01

    Retroviral transduction is the most commonly used strategy to obtain long-term expression of therapeutic genes. To efficiently transduce mammalian cells, a recombinant fibronectin molecule, RetroNectin, is generally used to juxtapose viral particles and cells, and thereby enhance viral uptake. Although this strategy has become widely adopted, in particular for the genetic modification of hematopoietic cells, several limitations apply. For example, it requires the use of culture systems that allow protein coating, something that is not possible for many of the closed cell culture systems that are used in clinical trials. Furthermore, efficient transduction is obtained only when culture systems can be exposed to centrifugation, an approach termed spin transduction. Here, we describe a novel and more potent strategy for the transduction of T cells that can be applied on a clinical scale. We show that RetroNectin can efficiently be coated onto epoxy-modified paramagnetic beads. After a blocking step, these beads can subsequently bind retroviral particles from viral supernatants, rendering such supernatants largely devoid of functional viral particles. Addition of these virus-loaded beads to activated T cells results in efficient retroviral infection. Importantly, transduction does not require the use of culture systems that are compatible with protein coating, nor is it dependent on centrifugation of either the viral supernatant or the cells. Finally, cell growth, phenotype, and function of spin-transduced versus bead-transduced cells are comparable. Viral coating of microbeads should facilitate the production of genetically modified cells, in particular for use in clinical trials.

  4. Maternal and fetal zidovudine pharmacokinetics during pregnancy and labour: too high dose infused at labour?

    PubMed

    Fauchet, Floris; Treluyer, Jean-Marc; Valade, Elodie; Benaboud, Sihem; Pannier, Emmanuelle; Firtion, Ghislaine; Foissac, Frantz; Bouazza, Naim; Urien, Saik; Hirt, Déborah

    2014-12-01

    The main goal of the study was to describe the pharmacokinetics of maternal zidovudine (ZDV) administration during pregnancy and labour and to evaluate their impact on fetal concentrations and exposures. A total of 195 HIV-infected pregnant and non-pregnant women aged 16-59 years were included and 273 maternal and 79 cord blood ZDV concentrations were collected. A population pharmacokinetic model was developed to describe ZDV concentrations as a function of time in the mother and the fetus. Fetal exposures resulting from maternal oral administration and infusion were estimated and compared with therapeutic exposures (3-5 mg l(-1)  h) and to exposure providing higher risk of toxicity (>8.4 mg l(-1)  h). Different protocols for ZDV administration during labour were simulated. The median fetal exposure and the percentage of children with values above 8.4 mg l(-1)  h were 3.20 mg l(-1)  h and 0% after maternal oral administration, respectively, and 9.71 mg l(-1)  h and 51% after maternal infusion during labour. Two options were considered to reduce fetal exposure during labour: (i) maternal infusion rates could be 1 mg kg(-1)  h(-1) during 1 h followed by 0.5 mg kg(-1)  h(-1) and (ii) the mother could only take oral ZDV every 5 h from start of labour until delivery with her neonate having their first ZDV dose as soon as possible after birth. Zidovudine exposures are very important during labour and during the first days of a neonate's life. Maternal ZDV dose should be reduced in addition to the neonate doses reduction already proposed. © 2014 The British Pharmacological Society.

  5. Maternal and fetal zidovudine pharmacokinetics during pregnancy and labour: too high dose infused at labour?

    PubMed Central

    Fauchet, Floris; Treluyer, Jean-Marc; Valade, Elodie; Benaboud, Sihem; Pannier, Emmanuelle; Firtion, Ghislaine; Foissac, Frantz; Bouazza, Naim; Urien, Saik; Hirt, Déborah

    2014-01-01

    Aims The main goal of the study was to describe the pharmacokinetics of maternal zidovudine (ZDV) administration during pregnancy and labour and to evaluate their impact on fetal concentrations and exposures. Methods A total of 195 HIV-infected pregnant and non-pregnant women aged 16–59 years were included and 273 maternal and 79 cord blood ZDV concentrations were collected. A population pharmacokinetic model was developed to describe ZDV concentrations as a function of time in the mother and the fetus. Fetal exposures resulting from maternal oral administration and infusion were estimated and compared with therapeutic exposures (3–5 mg l−1 h) and to exposure providing higher risk of toxicity (>8.4 mg l−1 h). Different protocols for ZDV administration during labour were simulated. Results The median fetal exposure and the percentage of children with values above 8.4 mg l−1 h were 3.20 mg l−1 h and 0% after maternal oral administration, respectively, and 9.71 mg l−1 h and 51% after maternal infusion during labour. Two options were considered to reduce fetal exposure during labour: (i) maternal infusion rates could be 1 mg kg−1 h−1 during 1 h followed by 0.5 mg kg−1 h−1 and (ii) the mother could only take oral ZDV every 5 h from start of labour until delivery with her neonate having their first ZDV dose as soon as possible after birth. Conclusions Zidovudine exposures are very important during labour and during the first days of a neonate's life. Maternal ZDV dose should be reduced in addition to the neonate doses reduction already proposed. PMID:25040510

  6. Oral sustained release tablets of zidovudine using binary blends of natural and synthetic polymers.

    PubMed

    Emeje, Martins; Olaleye, Olajide; Isimi, Christiana; Fortunak, Joseph; Byrn, Stephen; Kunle, Olobayo; Ofoefule, Sabinus

    2010-01-01

    Oral sustained release matrix tablets of zidovudine (ZDV) were prepared using different types, proportions and blends of carbopol 71G (C71) and a plant gum obtained from Abelmoschus esculentus (AEG). The effect of various formulation factors like polymer proportion, polymer type and pH of the dissolution medium on the in vitro release of the drug was studied, using the half change technique, in 900 ml of dissolution medium, at 100 rpm. Release kinetics were analyzed using Zero-order, Higuchi's square-root and Ritger-Peppas' empirical equations. In vitro release performance as revealed by the time taken for 70% of the drug to be released (t70%), showed that the release rate decreased with increase in polymer proportion. Matrix tablets containing 10 and 20% AEG were found to exhibit immediate-release characteristics. Matrix tablets containing 30% AEG showed t70% value of 204 min and extended the release up to 5 h, while matrix tablets containing 30% carbopol showed t70% value of 234 min and extended the release up to 6 h. Three blends of AEG and C71 at the ratio of 1:2, 2:1 and 1:3 showed t70% values of 132, 312 and 102 min respectively and extended the release up to 8 h. Mathematical analysis of the release kinetics indicated that the nature of drug release from the matrix tablets followed Fickian and anomalous release. Drug release from matrix tablets of zidovudine containing blends of AEG and C71 demonstrates the advantage of blending a natural and synthetic polymer over single polymer use.

  7. Release testing of retroviral vectors and gene-modified cells.

    PubMed

    Nordling, Diana; Kaiser, Anne; Reeves, Lilith

    2009-01-01

    This chapter will review the design and execution of release testing requirements for retroviral vectors and gene-modified cells consistent with ensuring the success of the clinical trial on the basis of current US regulatory requirements. It is the ethical and legal responsibility of the clinical trial sponsor(s) to ensure safety of the patients through proper evaluation of the drug products prior to use. Any clinical trial drug product used in human subjects must be produced and evaluated for safety, quality, purity, and effectiveness according to Current Good Manufacturing Practices appropriate for the stage of clinical development.

  8. Retroviral infection in Peruvian men who have sex with men.

    PubMed

    La Rosa, Alberto M; Zunt, Joseph R; Peinado, Jesus; Lama, Javier R; Ton, Thanh G N; Suarez, Luis; Pun, Monica; Cabezas, Cesar; Sanchez, Jorge

    2009-07-01

    We tested 2655 Peruvian men who have sex with men for the presence of retroviral infection. Human T cell lymphotropic virus type 1 (HTLV-1) was detected in 48 (1.8%) of the patients, HTLV-2 was detected in 28 (1.1%), and HTLV-1 and HTLV-2 were both detected in 5 (0.2%). Human immunodeficiency virus infection was detected in 329 (12.4%) of the patients; 24 (7.3%) had HTLV coinfection. Risk factors for HTLV-1 and HTLV-2 infection varied with sexual role.

  9. Toxicology and carcinogenesis studies of mixtures of 3'-azido-3'-deoxythymidine (AZT), lamivudine (3TC), nevirapine (NVP), and nelfinavir mesylate (NFV) (Cas Nos. 30516-87-1, 134678-17-4, 129618-40-2, 159989-65-8) in B6C3F1 Mice (transplacental exposure studies).

    PubMed

    2013-01-01

    Antiretroviral drugs are used to treat patients positive for the human immunovirus HIV-1, and increasingly treatments include a combination of such drugs. The noninfected children of women who are pregnant and receiving such treatment may also be exposed to the drugs by transplacental exposure. We studied the long-term effects of such transplacental exposure in mice by exposing pregnant mice to combinations of four such antiretroviral drugs for seven days and then observing their pups for two years following birth. The four drugs studied were 3′-azido-3′-deoxythymidine (AZT), lamivudine (3TC), nevirapine (NVP), and nelfinavir mesylate (NFV). Four different sets of exposure studies were performed: exposure to AZT; to AZT plus 3TC; to AZT, 3TC, and NVP; or to AZT, 3TC, and NFV. In each of these studies, groups of pregnant females were given one of three concentrations of the drug combinations seven times though a tube directly into their stomachs, and after birth their pups were maintained with no further exposure for two years. The offspring of another group of pregnant females not treated with the drugs served as controls. At the end of the study, tissues from more than 40 sites were examined for every animal. Survival of pups whose mothers were exposed to AZT or AZT plus 3TC was similar to their controls, while the survival rates for offspring of mice exposed to AZT, 3TC, and NVP or AZT, 3TC, and NFP were lower than for controls. In most cases the body weights of pups from mothers exposed were slightly less than those of the controls. There were slight increases in the incidences of thyroid gland tumors and skin tumors in the female pups of mothers exposed to AZT alone and of lung tumors in female pups of mothers exposed to AZT plus 3TC. For offspring of mothers exposed to AZT, 3TC, and NVP there were increased incidences of skin tumors in both male and female pups, and more so in the males. We conclude that exposure to the combination of AZT, 3TC, and NVP

  10. A new generation of retroviral producer cells: predictable and stable virus production by Flp-mediated site-specific integration of retroviral vectors.

    PubMed

    Schucht, R; Coroadinha, A S; Zanta-Boussif, M A; Verhoeyen, E; Carrondo, M J T; Hauser, H; Wirth, Dagmar

    2006-08-01

    We developed a new strategy that provides well-defined high-titer producer cells for recombinant retroviruses in a minimum amount of time. The strategy involves the targeted integration of the retroviral vector into a chromosomal locus with favorable properties. For proof of concept we established a novel HEK293-based retroviral producer cell line, called Flp293A, with a single-copy retroviral vector integrated at a selected chromosomal locus. The vector was flanked by noninteracting Flp-recombinase recognition sites and was exchanged for different retroviral vectors via Flp-mediated cassette exchange. All analyzed cell clones showed correct integration and identical titers for each of the vectors, confirming that the expression characteristics from the parental cell were preserved. Titers up to 2.5 x 10(7) infectious particles/10(6) cells were obtained. Also, high-titer producer cells for a therapeutic vector that encodes the 8.9-kb collagen VII cDNA in a marker-free cassette were obtained within 3 weeks without screening. Thus, we provide evidence that the precise integration of viral vectors into a favorable chromosomal locus leads to high and predictable virus production. This method is compatible with other retroviral vectors, including self-inactivating vectors and marker-free vectors. Further, it provides a tool for evaluation of different retroviral vector designs.

  11. The Early Years of Retroviral Protease Crystal Structures

    PubMed Central

    Miller, Maria

    2010-01-01

    Soon after its discovery, the attempts to develop anti-AIDS therapeutics focused on the retroviral protease (PR) — an enzyme used by lentiviruses to process the precursor polypeptide into mature viral proteins. An urgent need for the three-dimensional structure of PR to guide rational drug design prompted efforts to produce milligram quantities of this enzyme. However, only minute amounts of PR were present in the HIV-1 and HIV-2 viruses, and initial attempts to express this protein in bacteria were not successful. This review describes X-ray crystallographic studies of the retroviral proteases carried out at NCI-Frederick in the late 1980s and early 1990s and puts into perspective the crucial role that the total protein chemical synthesis played in unraveling the structure, mechanism of action, and inhibition of HIV-1 PR. Notably, the first fully correct structure of HIV-1 PR and the first cocrystal structure of its complex with an inhibitor (a substrate-derived, reduced isostere hexapeptide MVT-101) were determined using chemically synthesized protein. Most importantly, these sets of coordinates were made freely available to the research community and were used worldwide to solve X-ray structures of HIV-1 PR complexes with an array of inhibitors and set in motion a variety of theoretical studies. Publication of the structure of chemically synthesized HIV-1 PR complexed with MVT-101 preceded only by six years the approval of the first PR inhibitor as an anti-AIDS drug. PMID:20593466

  12. Changing T cell specificity by retroviral T cell receptor display

    PubMed Central

    Kessels, Helmut W. H. G.; van den Boom, Marly D.; Spits, Hergen; Hooijberg, Erik; Schumacher, Ton N. M.

    2000-01-01

    The diversity of the T cell receptor (TCR) repertoire is limited, because of the processes of positive and negative T cell selection. To obtain T cells with specificities beyond the immune system's capacity, we have developed a strategy for retroviral TCR display. In this approach, a library of T cell variants is generated in vitro and introduced into a TCR-negative murine T cell line by retroviral transfer. We document the value of TCR display by the creation of a library of an influenza A-specific TCR and the subsequent in vitro selection of TCRs that either recognize the parental influenza epitope or that have acquired a specificity for a different influenza A strain. The resulting in vitro selected TCRs induce efficient T cell activation after ligand recognition and are of equal or higher potency than the in vivo generated parent receptor. TCR display should prove a useful strategy for the generation of high-affinity tumor-specific TCRs for gene transfer purposes. PMID:11121060

  13. Retroviral Transcriptional Regulation and Embryonic Stem Cells: War and Peace

    PubMed Central

    Schlesinger, Sharon

    2014-01-01

    Retroviruses have evolved complex transcriptional enhancers and promoters that allow their replication in a wide range of tissue and cell types. Embryonic stem (ES) cells, however, characteristically suppress transcription of proviruses formed after infection by exogenous retroviruses and also of most members of the vast array of endogenous retroviruses in the genome. These cells have unusual profiles of transcribed genes and are poised to make rapid changes in those profiles upon induction of differentiation. Many of the transcription factors in ES cells control both host and retroviral genes coordinately, such that retroviral expression patterns can serve as markers of ES cell pluripotency. This overlap is not coincidental; retrovirus-derived regulatory sequences are often used to control cellular genes important for pluripotency. These sequences specify the temporal control and perhaps “noisy” control of cellular genes that direct proper cell gene expression in primitive cells and their differentiating progeny. The evidence suggests that the viral elements have been domesticated for host needs, reflecting the wide-ranging exploitation of any and all available DNA sequences in assembling regulatory networks. PMID:25547290

  14. Retroviral transcriptional regulation and embryonic stem cells: war and peace.

    PubMed

    Schlesinger, Sharon; Goff, Stephen P

    2015-03-01

    Retroviruses have evolved complex transcriptional enhancers and promoters that allow their replication in a wide range of tissue and cell types. Embryonic stem (ES) cells, however, characteristically suppress transcription of proviruses formed after infection by exogenous retroviruses and also of most members of the vast array of endogenous retroviruses in the genome. These cells have unusual profiles of transcribed genes and are poised to make rapid changes in those profiles upon induction of differentiation. Many of the transcription factors in ES cells control both host and retroviral genes coordinately, such that retroviral expression patterns can serve as markers of ES cell pluripotency. This overlap is not coincidental; retrovirus-derived regulatory sequences are often used to control cellular genes important for pluripotency. These sequences specify the temporal control and perhaps "noisy" control of cellular genes that direct proper cell gene expression in primitive cells and their differentiating progeny. The evidence suggests that the viral elements have been domesticated for host needs, reflecting the wide-ranging exploitation of any and all available DNA sequences in assembling regulatory networks.

  15. Genetic assay for multimerization of retroviral gag polyproteins.

    PubMed Central

    Luban, J; Alin, K B; Bossolt, K L; Humaran, T; Goff, S P

    1992-01-01

    We have established a genetic assay for the multimerization of retroviral gag polyproteins. This assay is based on the GAL4 two-hybrid system for studying protein-protein interactions (S. Fields and O. Song, Nature (London) 340:245-246, 1989). In our initial experiments, we generated Saccharomyces cerevisiae plasmids that separately express the GAL4 DNA-binding and GAL4 activation domains fused to the human immunodeficiency virus type 1 (HIV-1) gag polyprotein, Pr55gag. The coexpression of these two hybrid proteins in S. cerevisiae results in the association of the GAL4 domains and the potent activation of an integrated GAL4-responsive lacZ indicator gene. Similar results were obtained with plasmids encoding GAL4-Moloney murine leukemia virus (M-MuLV) gag polyprotein hybrid proteins. In contrast, the heterologous GAL4-HIV-1 gag and GAL4-M-MuLV gag fusion proteins were unable to interact with each other to induce lacZ expression. The results suggest that this yeast system provides a rapid and specific assay for the interactions of retroviral gag proteins that occur during virion assembly. Images PMID:1629970

  16. Evaluation of Bystander Cell Killing Effects in Suicide Gene Therapy of Cancer: Engineered Thymidylate Kinase (TMPK)/AZT Enzyme-Prodrug Axis.

    PubMed

    Sato, Takeya; Neschadim, Anton; Nakagawa, Ryo; Yanagisawa, Teruyuki; Medin, Jeffrey A

    2015-01-01

    Suicide gene therapy of cancer (SGTC) entails the introduction of a cDNA sequence into tumor cells whose polypeptide product is capable of either directly activating apoptotic pathways itself or facilitating the activation of pharmacologic agents that do so. The latter class of SGTC approaches is of the greater utility in cancer therapy owing to the ability of some small, activated cytotoxic compounds to diffuse from their site of activation into neighboring malignant cells, where they can also mediate destruction. This phenomenon, termed "bystander killing", can be highly advantageous in driving significant tumor regression in vivo without the requirement of transduction of each and every tumor cell with the suicide gene. We have developed a robust suicide gene therapy enzyme/prodrug system based on an engineered variant of the human thymidylate kinase (TMPK), which has been endowed with the ability to drive azidothymidine (AZT) activation. Delivery of this suicide gene sequence into tumors by means of recombinant lentivirus-mediated transduction embodies an SGTC strategy that successfully employs bystander cell killing as a mechanism to achieve significant ablation of solid tumors in vivo. Thus, this engineered TMPK/AZT suicide gene therapy axis holds great promise for clinical application in the treatment of inoperable solid tumors in the neoadjuvant setting. Here we present detailed procedures for the preparation of recombinant TMPK-based lentivirus, transduction of target cells, and various approaches for the evaluation of bystander cell killing effects in SGCT in both in vitro and in vivo models.

  17. Conformational analysis of the anti-HIV Nikavir prodrug: comparisons with AZT and Thymidine, and establishment of structure-activity relationships/tendencies in other 6'-derivatives.

    PubMed

    El-Sayed, Ahmed A; Tamara Molina, A; Álvarez-Ros, M C; Alcolea Palafox, M

    2015-01-01

    A comprehensive theoretical conformational analysis of the anti-HIV Nikavir prodrug was carried out; this prodrug has noticeable advantage over the approved drug AZT. The whole conformational parameters (χ, α, β, γ, δ, ϕ, P and νmax) were analysed as well as the NBO natural atomic charges. The calculations were carried out by means of DFT/B3LYP and ab initio MP2 methods with full relaxation of all geometrical parameters. The search located at least 67 stable structures, 4 of which were within a 1 kcal/mol electronic energy range of the global minimum. By MP2 it corresponds to the calculated values of the exocyclic torsional angles χ=-108.0°, β=14.5°, γ=76.7° and ε=71.5°. The results obtained are in accordance to those found in related anti-HIV nucleoside analogues. Comparisons of the conformers with those determined in the common anti-HIV drug AZT were carried out. A detailed analysis of the lowest vibrations (<200 cm(-1)) in the best conformer of Nikavir was carried out. The most stable hydrated cluster of this conformer with 20 explicit water molecules was determined. Calculations in five of its 6'-derivatives were performed to identify structural trends that might correlate with the anti-HIV activity of these compounds. Ten structure-activity relationships/tendencies were established that can help for the design of new drugs. Several recommendations for this design were expressed.

  18. AIDS Issues (Part 1). Hearings before the Subcommittee on Health and the Environment of the Committee on Energy and Commerce. House of Representatives, One Hundredth Congress, First Session (March 10 1987--Cost and Availability of AZT; April 27, 1987--AIDS and Minorities; September 22, 1987--AIDS Research and Education).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Energy and Commerce.

    The texts of three hearings on issues connected with AIDS (Acquired Immune Deficiency Syndrome) are recorded in this document. The first hearing concerned the availability and cost of the drug azidothymidine (AZT) for victims of the disease and considered such questions as what a fair price for AZT is, who will pay for people currently being…

  19. Superior Effectiveness of Zidovudine Compared With Tenofovir When Combined With Nevirapine-based Antiretroviral Therapy in a Large Nigerian Cohort.

    PubMed

    Scarsi, Kimberly K; Eisen, Geoffrey; Darin, Kristin M; Meloni, Seema T; Rawizza, Holly E; Tchetgen Tchetgen, Eric J; Agbaji, Oche O; Onwujekwe, Daniel I; Gashau, Wadzani; Nkado, Reuben; Okonkwo, Prosper; Murphy, Robert L; Kanki, Phyllis J

    2016-02-15

    Despite sparse efficacy data, tenofovir-emtricitabine or tenofovir-lamivudine plus nevirapine is used in many resource-constrained settings. This retrospective cohort study included patients initiating nevirapine-based antiretroviral therapy (ART) with either tenofovir-emtricitabine or lamivudine (tenofovir group) or zidovudine-lamivudine (zidovudine group). Clinical, virologic, and immunologic evaluations were performed at baseline and every 6 months. Virologic failure was defined as 2 consecutive human immunodeficiency virus (HIV)-RNA values >1000 copies/mL. Patients were included from ART initiation until time of failure, regimen switch, discontinuation, or last HIV-RNA measurement. Cox proportional hazards regression was used to model factors influencing time to failure. Bias due to dependent censoring was investigated via inverse probability weighted pooled logistic regression. A total of 5547 patients were evaluated; 1484 (26.8%) were in the tenofovir group and 4063 (73.2%) were in the zidovudine group. In the adjusted model, tenofovir regimen (hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.21-1.79) and higher baseline log10 HIV-RNA (HR, 1.15; 95% CI, 1.03-1.28) were associated with virologic failure. Higher baseline log10 CD4+ cell count (HR, 0.50; 95% CI, .40-.63) and increasing age (HR, 0.98; 95% CI, .97-.99) decreased the risk of virologic failure. Inverse probability weighting results were consistent with the primary analysis. Compared with zidovudine-lamivudine, the use of tenofovir-lamivudine or emtricitabine in combination with nevirapine was a strong predictor of virologic failure in our cohort, which was not explained by other risk factors or criteria for regimen selection. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America.

  20. Concurrent zidovudine levels in semen and serum determined by radioimmunoassay in patients with AIDS or AIDS-related complex

    SciTech Connect

    Henry, K.; Chinnock, B.J.; Quinn, R.P.; Fletcher, C.V.; de Miranda, P.; Balfour, H.H.

    1988-05-27

    Zidovudine was present in the semen and serum of six patients with acquired immunodeficiency syndrome or the related complex who were receiving 200 mg of the drug orally every four to six hours. Mean semen zidovudine levels (as measured by a new radioimmunoassay) in samples collected 0.75 to 1.25 hours after oral dosing were 3.63 to 7.19 ..mu..mol/L. Levels in semen samples collected 3.0 to 4.5 hours after oral dosing were 1.68 to 6.43 ..mu..mol/L. These values are above the in vitro minimum inhibitory concentration for the human immunodeficiency virus type 1 (HIV-1). Mean serum concentrations at the early and late times after oral dosing were 0.22 to 3.07 ..mu..mol/L and 0.10 to 1.42 ..mu..mol/L, respectively. Ratios of semen/serum zidovudine levels ranged from 1.3 to 20.4. It is possible that a pH-dependent trapping mechanism, which has been described in the prostate for other antibiotics, was responsible for the relatively high semen levels observed.

  1. Retroviral vectors for homologous recombination provide efficient cloning and expression in mammalian cells.

    PubMed

    Kobayashi, Eiji; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Horii, Masae; Hamana, Hiroshi; Nagai, Terumi; Muraguchi, Atsushi

    2014-02-14

    Homologous recombination technologies enable high-throughput cloning and the seamless insertion of any DNA fragment into expression vectors. Additionally, retroviral vectors offer a fast and efficient method for transducing and expressing genes in mammalian cells, including lymphocytes. However, homologous recombination cannot be used to insert DNA fragments into retroviral vectors; retroviral vectors contain two homologous regions, the 5'- and 3'-long terminal repeats, between which homologous recombination occurs preferentially. In this study, we have modified a retroviral vector to enable the cloning of DNA fragments through homologous recombination. To this end, we inserted a bacterial selection marker in a region adjacent to the gene insertion site. We used the modified retroviral vector and homologous recombination to clone T-cell receptors (TCRs) from single Epstein Barr virus-specific human T cells in a high-throughput and comprehensive manner and to efficiently evaluate their function by transducing the TCRs into a murine T-cell line through retroviral infection. In conclusion, the modified retroviral vectors, in combination with the homologous recombination method, are powerful tools for the high-throughput cloning of cDNAs and their efficient functional analysis.

  2. Mechanisms and Factors that Influence High Frequency Retroviral Recombination

    PubMed Central

    Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga; Mens, Helene; Pathak, Vinay K.; Hu, Wei-Shau

    2011-01-01

    With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment, and vaccine development. PMID:21994801

  3. Retroviral display in gene therapy, protein engineering, and vaccine development.

    PubMed

    Urban, Johannes H; Merten, Christoph A

    2011-01-21

    The display and analysis of proteins expressed on biological surfaces has become an attractive tool for the study of molecular interactions in enzymology, protein engineering, and high-throughput screening. Among the growing number of established display systems, retroviruses offer a unique and fully mammalian platform for the expression of correctly folded and post-translationally modified proteins in the context of cell plasma membrane-derived particles. This is of special interest for therapeutic applications such as gene therapy and vaccine development and also offers advantages for the engineering of mammalian proteins toward customized binding affinities and catalytic activities. This review critically summarizes the basic concepts and applications of retroviral display and analyses its benefits in comparison to other display techniques.

  4. Retroviral Integrase Proteins and HIV-1 DNA Integration*

    PubMed Central

    Krishnan, Lavanya; Engelman, Alan

    2012-01-01

    Retroviral integrases catalyze two reactions, 3′-processing of viral DNA ends, followed by integration of the processed ends into chromosomal DNA. X-ray crystal structures of integrase-DNA complexes from prototype foamy virus, a member of the Spumavirus genus of Retroviridae, have revealed the structural basis of integration and how clinically relevant integrase strand transfer inhibitors work. Underscoring the translational potential of targeting virus-host interactions, small molecules that bind at the host factor lens epithelium-derived growth factor/p75-binding site on HIV-1 integrase promote dimerization and inhibit integrase-viral DNA assembly and catalysis. Here, we review recent advances in our knowledge of HIV-1 DNA integration, as well as future research directions. PMID:23043109

  5. New insight into transcription of human endogenous retroviral elements.

    PubMed

    Pačes, Jan; Huang, Yao-Ting; Pačes, Václav; Rídl, Jakub; Chang, Chung-Ming

    2013-03-25

    It is generally assumed that human endogenous retroviral elements (HERVs) belong to the class of genomic repetitive nucleotide sequences often called 'junk DNA'. These elements were categorized to families, and members of some of these families (e.g. HERV-H, HERV-W and HERV-K) were shown to be transcribed. These transcriptions were associated with several severe diseases such as mental disorders, AIDS, autoimmune diseases and cancer. In this review we discuss several bioinformatics strategies for genome-wide scan of HERVs transcription using high-throughput RNA sequencing on several platforms. We show that many more HERVs than previously described are transcribed to various levels and we discuss possible implications of these transcriptions.

  6. Endogenous non-retroviral RNA virus elements in mammalian genomes.

    PubMed

    Horie, Masayuki; Honda, Tomoyuki; Suzuki, Yoshiyuki; Kobayashi, Yuki; Daito, Takuji; Oshida, Tatsuo; Ikuta, Kazuyoshi; Jern, Patric; Gojobori, Takashi; Coffin, John M; Tomonaga, Keizo

    2010-01-07

    Retroviruses are the only group of viruses known to have left a fossil record, in the form of endogenous proviruses, and approximately 8% of the human genome is made up of these elements. Although many other viruses, including non-retroviral RNA viruses, are known to generate DNA forms of their own genomes during replication, none has been found as DNA in the germline of animals. Bornaviruses, a genus of non-segmented, negative-sense RNA virus, are unique among RNA viruses in that they establish persistent infection in the cell nucleus. Here we show that elements homologous to the nucleoprotein (N) gene of bornavirus exist in the genomes of several mammalian species, including humans, non-human primates, rodents and elephants. These sequences have been designated endogenous Borna-like N (EBLN) elements. Some of the primate EBLNs contain an intact open reading frame (ORF) and are expressed as mRNA. Phylogenetic analyses showed that EBLNs seem to have been generated by different insertional events in each specific animal family. Furthermore, the EBLN of a ground squirrel was formed by a recent integration event, whereas those in primates must have been formed more than 40 million years ago. We also show that the N mRNA of a current mammalian bornavirus, Borna disease virus (BDV), can form EBLN-like elements in the genomes of persistently infected cultured cells. Our results provide the first evidence for endogenization of non-retroviral virus-derived elements in mammalian genomes and give novel insights not only into generation of endogenous elements, but also into a role of bornavirus as a source of genetic novelty in its host.

  7. Alteration of Blood–Brain Barrier Integrity by Retroviral Infection

    PubMed Central

    Afonso, Philippe V.; Ozden, Simona; Cumont, Marie-Christine; Seilhean, Danielle; Cartier, Luis; Rezaie, Payam; Mason, Sarah; Lambert, Sophie; Huerre, Michel; Gessain, Antoine; Couraud, Pierre-Olivier; Pique, Claudine

    2008-01-01

    The blood–brain barrier (BBB), which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1) Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans), both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies. PMID:19008946

  8. The early years of retroviral protease crystal structures.

    PubMed

    Miller, Maria

    2010-01-01

    Soon after its discovery, the attempts to develop anti-AIDS therapeutics focused on the retroviral protease (PR)-an enzyme used by lentiviruses to process the precursor polypeptide into mature viral proteins. An urgent need for the three-dimensional structure of PR to guide rational drug design prompted efforts to produce milligram quantities of this enzyme. However, only minute amounts of PR were present in the HIV-1 and HIV-2 viruses, and initial attempts to express this protein in bacteria were not successful. This review describes X-ray crystallographic studies of the retroviral proteases carried out at NCI-Frederick in the late 1980s and early 1990s and puts into perspective the crucial role that the total protein chemical synthesis played in unraveling the structure, mechanism of action, and inhibition of HIV-1 PR. Notably, the first fully correct structure of HIV-1 PR and the first cocrystal structure of its complex with an inhibitor (a substrate-derived, reduced isostere hexapeptide MVT-101) were determined using chemically synthesized protein. Most importantly, these sets of coordinates were made freely available to the research community and were used worldwide to solve X-ray structures of HIV-1 PR complexes with an array of inhibitors and set in motion a variety of theoretical studies. Publication of the structure of chemically synthesized HIV-1 PR complexed with MVT-101 preceded only by six years the approval of the first PR inhibitor as an anti-AIDS drug. Copyright (c) 2010 Wiley Periodicals, Inc.

  9. Role of ESCRT-I in Retroviral Budding

    PubMed Central

    Martin-Serrano, Juan; Zang, Trinity; Bieniasz, Paul D.

    2003-01-01

    Retroviral late-budding (L) domains are required for the efficient release of nascent virions. The three known types of L domain, designated according to essential tetrapeptide motifs (PTAP, PPXY, or YPDL), each bind distinct cellular cofactors. We and others have demonstrated that recruitment of an ESCRT-I subunit, Tsg101, a component of the class E vacuolar protein sorting (VPS) machinery, is required for the budding of viruses, such as human immunodeficiency virus type 1 (HIV-1) and Ebola virus, that encode a PTAP-type L domain, but subsequent events remain undefined. In this study, we demonstrate that VPS28, a second component of ESCRT-I, binds to a sequence close to the Tsg101 C terminus and is therefore recruited to the plasma membrane by HIV-1 Gag. In addition, we show that Tsg101 exhibits a multimerization activity. Using a complementation assay in which Tsg101 is artificially recruited to sites of HIV-1 assembly, we demonstrate that the integrity of the VPS28 binding site within Tsg101 is required for particle budding. In addition, mutation of a putative leucine zipper or residues important for Tsg101 multimerization also impairs the ability of Tsg101 to support HIV-1 budding. A minimal multimerizing Tsg101 domain is a dominant negative inhibitor of PTAP-mediated HIV-1 budding but does not inhibit YPDL-type or PPXY-type L-domain function. Nevertheless, YDPL-type L-domain activity is inhibited by expression of a catalytically inactive mutant of the class E VPS ATPase VPS4. These results indicate that all three classes of retroviral L domains require a functioning class E VPS pathway in order to effect budding. However, the PTAP-type L domain appears to be unique in its requirement for an intact, or nearly intact, ESCRT-I complex. PMID:12663786

  10. Role of ESCRT-I in retroviral budding.

    PubMed

    Martin-Serrano, Juan; Zang, Trinity; Bieniasz, Paul D

    2003-04-01

    Retroviral late-budding (L) domains are required for the efficient release of nascent virions. The three known types of L domain, designated according to essential tetrapeptide motifs (PTAP, PPXY, or YPDL), each bind distinct cellular cofactors. We and others have demonstrated that recruitment of an ESCRT-I subunit, Tsg101, a component of the class E vacuolar protein sorting (VPS) machinery, is required for the budding of viruses, such as human immunodeficiency virus type 1 (HIV-1) and Ebola virus, that encode a PTAP-type L domain, but subsequent events remain undefined. In this study, we demonstrate that VPS28, a second component of ESCRT-I, binds to a sequence close to the Tsg101 C terminus and is therefore recruited to the plasma membrane by HIV-1 Gag. In addition, we show that Tsg101 exhibits a multimerization activity. Using a complementation assay in which Tsg101 is artificially recruited to sites of HIV-1 assembly, we demonstrate that the integrity of the VPS28 binding site within Tsg101 is required for particle budding. In addition, mutation of a putative leucine zipper or residues important for Tsg101 multimerization also impairs the ability of Tsg101 to support HIV-1 budding. A minimal multimerizing Tsg101 domain is a dominant negative inhibitor of PTAP-mediated HIV-1 budding but does not inhibit YPDL-type or PPXY-type L-domain function. Nevertheless, YDPL-type L-domain activity is inhibited by expression of a catalytically inactive mutant of the class E VPS ATPase VPS4. These results indicate that all three classes of retroviral L domains require a functioning class E VPS pathway in order to effect budding. However, the PTAP-type L domain appears to be unique in its requirement for an intact, or nearly intact, ESCRT-I complex.

  11. Detection of a human intracisternal A-type retroviral particle antigenically related to HIV

    NASA Technical Reports Server (NTRS)

    Garry, R. F.; Fermin, C. D.; Hart, D. J.; Alexander, S. S.; Donehower, L. A.; Luo-Zhang, H.

    1990-01-01

    Sjogren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjogren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.

  12. Detection of a human intracisternal A-type retroviral particle antigenically related to HIV

    NASA Technical Reports Server (NTRS)

    Garry, R. F.; Fermin, C. D.; Hart, D. J.; Alexander, S. S.; Donehower, L. A.; Luo-Zhang, H.

    1990-01-01

    Sjogren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjogren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.

  13. Immunological outcomes of Tenofovir versus Zidovudine-based regimens among people living with HIV/AIDS: a two years retrospective cohort study.

    PubMed

    Ayele, Teshale; Jarso, Habtemu; Mamo, Girma

    2017-02-01

    Tenofovir (TDF) based regimen was reported to have better immunological outcomes. Unfortunately, there is limited information regarding the immunologic outcome associated with this regimen in Ethiopia, as its routine utilization in this setting begun since 2013. A 2 years retrospective cohort study was conducted at Jimma University Specialized Hospital, 346 km Southwest of Addis Ababa, Ethiopia. A total of 280 patients' data from September 2012 to July 2014 was extracted from records from February 10, 2015 to March 10, 2015. Records were selected using a simple random sampling technique. Data on socio-demographic, clinical and drug related variables were collected; entered into EpiData 3.1 and analyzed by STATA 13.1. Mixed effect linear regression was performed to assess difference in CD4+ change between groups adjusting for baseline characteristics. The change in predicted CD4 count attributed to each regimen was also assessed by marginal analysis. P < 0.05 for slopes of the random effect linear regression was used as indicators for presence of association. The mean (SD) duration of cohort follow up was 714.2 (69.6) and 708.8 (78.9) days (P = 0.753) for TDF and AZT groups respectively. The minimum follow up duration was 7.4 and 8.9 months for TDF and AZT groups respectively. Most of TDF (93.6%) and AZT (91.4%) groups completed their follow up, 5 (3.6%) TDF and 6 (4.3%) AZT groups died and 4 (2.9%) TDF and 6 (4.3%) AZT groups were lost for follow-up (P = 0.769). There was statistically significant difference in immunologic recovery between the groups (B = +34.08, 95% CI [7.8, 60.35], P = 0.027) over time. The predicted CD4+ count for TDF/3TC/EFV was (B = +347.65 cells/mm(3), P < 0.001) whereas that of AZT/3TC/EFV was (B = +281.54 cells/mm(3), P < 0.001). TDF based regimens have shown more efficacy compared to AZT based regimens though AZT based regimens are more affordable in low income countries like Ethiopia. However, we recommend further

  14. [Ultrastructural aspects of the HIV-1 infection in human placental villi with zidovudine treatment].

    PubMed

    Castejón-Sandoval, Olivar Clemente; López-González, Angela Josmar; Castejón-Morett, Oliver Clemente

    2010-07-01

    HIV patients with normal placental villi can suffer degenerative changes, the hormones that maintain pregnancy (HCG and progesterone) are diminishing, the pH of blood and oxygen tensions lower. To demonstrate ultrastructural degenerative changes in placental villi at term of pregnant women infected by HIV-1 with zidovudine treatment. Four placentas at term from seropositive mothers were analyzed; three specimens of each one were processed with conventional transmission electron microscopy. The results were compared with four control cases. Particles belonging to the viral structure associated with the microvilli of the syncytium and cytoplasmic regions were found. Were observed: interruptions of syncytial plasma membrane, syncytial edema; loss of ribosomes at level of RER, disappearance of mitochondria, Golgi complex, RER, lysosomes and cytoplasmic filaments, dissolution of hyaloplasmic matrix, filopodiums of syncytial membrane, aggregated nuclear heterochromatin and dilated perinuclear cistern. Macrophagues had numerous particles into cytoplasm, probably pertaining to electron dense material contained in the viral nucleocapsid, also observed in the stromal region close to the endothelium of the villus. Some myofibroblasts were detected suffering a process of cellular death with cariorexis event. These changes indicate that the cytopathic effect spreads from peripheral syncytium to stromal zone suggesting that the damaged placental barrier don't have the better conditions for the transmission of gases, nutrients and metabolites toward fetal circulation.

  15. Exposure to zidovudine adversely affects mitochondrial turnover in primary T cells.

    PubMed

    Wallace, Zoë R; Sanderson, Sharon; Simon, Anna Katarina; Dorrell, Lucy

    2016-09-01

    Zidovudine (ZDV) is a widely used component of antiretroviral therapy (ART) in resource-limited settings, despite its known adverse effects, which include mitochondrial toxicity in muscle, liver and adipose tissue. It has also been associated with impaired immunological recovery. We hypothesised that ZDV might impair mitochondrial health and survival of primary T cells. We performed a cross-sectional analysis of mitochondrial function, mitophagy and susceptibility to apoptosis in healthy donor primary T cells after exposure to ZDV in vitro, together with T cells from patients who were virologically suppressed on ZDV-containing ART regimens for ≥1 year and age-matched subjects receiving non-ZDV ART regimens. The proportion of T cells expressing mitochondrial reactive oxygen species (mtROS) was significantly higher after in vitro (CD4(+) T cells and CD8(+) T cells) and in vivo (CD4(+) T cells) exposure to ZDV than other antiretroviral agents. We did not detect any effect of ZDV on mitophagy, as indicated by change in autophagic flux. However, spontaneous apoptosis, indicated by upregulation of caspase-3 was greater in ZDV-exposed T cells. In conclusion, ZDV exposure was associated with impaired mitochondrial turnover and increased susceptibility to apoptosis in T cells. These mechanisms could contribute to sub-optimal immune reconstitution.

  16. Pharmacokinetic interaction between zidovudine and trimethoprim/sulphamethoxazole in HIV-1 infected children.

    PubMed

    Dallas, S; E Read, S; King, S; Koren, G; Bendayan, R

    2000-09-01

    To evaluate the effect of the antimicrobial agent trimethoprim/sulphamethoxazole (TMP/SMX) on the pharmacokinetic properties of the antiretroviral drug zidovudine (ZDV). This single dose, open label, crossover study involved the oral administration of ZDV (150 mg/m²) alone and in combination with oral TMP/SMX (2.5 mg/kg) on two separate occasions. Serial blood samples (0 to 8 h) were collected, and concentrations of ZDV and its glucuronide metabolite were quantified using a radioimmunoassay. ZDV pharmacokinetics were determined by noncompartmental analysis. Six HIV-1 infected children aged four months to five years were recruited from the HIV clinic at The Hospital for Sick Children, Toronto, Ontario. Only three patients completed both study phases and were included in the pharmacokinetic analysis. With TMP/SMX therapy, no statistically significant changes were observed in ZDV pharmacokinetic parameters. However, there was a trend towards increased ZDV half-life and area under the concentration versus time curve, as well as decreased apparent oral clearance. Similarly, a trend towards an increased half-life of the ZDV-glucuronide metabolite was also observed. The changes in ZDV pharmacokinetics in the presence of TMP/SMX did not reach statistical significance, most likely due to the limited number of patients involved. Despite the limited data, a possible interaction between ZDV and TMP/SMX in young HIV-1 infected children should be considered, and patients may require close clinical monitoring.

  17. Biphasic elimination of tenofovir diphosphate and nonlinear pharmacokinetics of zidovudine triphosphate in a microdosing study.

    PubMed

    Chen, Jianmeng; Flexner, Charles; Liberman, Rosa G; Skipper, Paul L; Louissaint, Nicolette A; Tannenbaum, Steven R; Hendrix, Craig W; Fuchs, Edward J

    2012-12-15

    Phase 0 studies can provide initial pharmacokinetics (PKs) data in humans and help to facilitate early drug development, but their predictive value for standard dosing is controversial. To evaluate the prediction of microdosing for active intracellular drug metabolites, we compared the PK profile of 2 antiretroviral drugs, zidovudine (ZDV) and tenofovir (TFV), in microdose and standard dosing regimens. We administered a microdose (100 μg) of C-labeled drug (ZDV or tenofovir disoproxil fumarate) with or without a standard unlabelled dose (300 mg) to healthy volunteers. Both the parent drug in plasma and the active metabolite, ZDV-triphosphate (ZDV-TP) or TFV-diphosphate (TFV-DP) in peripheral blood mononuclear cells (PBMCs) and CD4 cells were measured by accelerator mass spectrometry. The intracellular ZDV-TP concentration increased less than proportionally over the dose range studied (100 μg-300 mg), whereas the intracellular TFV-DP PKs were linear over the same dose range. ZDV-TP concentrations were lower in CD4 cells versus total PBMCs, whereas TFV-DP concentrations were not different in CD4 cells and PBMCs. Our data were consistent with a rate-limiting step in the intracellular phosphorylation of ZDV but not TFV. Accelerator mass spectrometry shows promise for predicting the PK of active intracellular metabolites of nucleosides, but nonlinearity of PK may be seen with some drugs.

  18. High exposure to zidovudine during the first 2 weeks of life and concentration-toxicity relationships.

    PubMed

    Hirt, Déborah; Warszawski, Josiane; Firtion, Ghislaine; Giraud, Carole; Chappuy, Hélène; Lechenadec, Jérôme; Benaboud, Sihem; Urien, Saïk; Blanche, Stéphane; Tréluyer, Jean-Marc

    2013-08-15

    The aims of the study were in a large group of neonates to identify the relative effect of bodyweight, postnatal age, and gestational age on zidovudine (ZDV) pharmacokinetics; to link concentrations with lactate and hemoglobin levels; and to find the more appropriate neonatal ZDV dose. In 484 neonates aged 3-30 days, born to HIV-infected mothers, 767 ZDV and 417 ZDV glucuronide concentrations were collected. Using a population approach, ZDV clearance per kilogram increased with postnatal age but not with gestational age. High neonatal exposures were found as follows: 14,025 ng/mL·h the first week and 6528 ng/mL·h the second week in comparison to 3000 ng/mL·h in adults. At month 1, median lactate level was 2.8 mmol/L (60%, ≥2.5 mmol/L) and median hemoglobin was 10.1 g/dL (90%, <12 g/dL). ZDV trough concentrations at first sampling (days 3-7) or at last sampling (day 20 ± 10) were significantly negatively correlated to hemoglobin at months 1, 3, and 6 (P < 0.02). ZDV maximal or trough concentrations at days 3-7 and at day 20 ± 10 were significantly positively correlated to lactate levels at months 3 and 6, respectively. To obtain an exposure comparable to adults, which should reduce neonatal toxicity, doses should to be decreased during the first 2 weeks of life.

  19. Biphasic Elimination of Tenofovir Diphosphate and Nonlinear Pharmacokinetics of Zidovudine Triphosphate in a Microdosing Study

    PubMed Central

    Chen, Jianmeng; Flexner, Charles; Liberman, Rosa G.; Skipper, Paul L.; Louissaint, Nicolette; Tannenbaum, Steven R.; Hendrix, Craig; Fuchs, Edward

    2012-01-01

    Objective Phase 0 studies can provide initial pharmacokinetics (PK) data in humans and help to facilitate early drug development, but their predictive value for standard dosing is controversial. To evaluate the prediction of microdosing for active intracellular drug metabolites, we compared the PK profile of two antiretroviral drugs, zidovudine (ZDV) and tenofovir (TFV), in microdose and standard dosing regimens. Study Design We administered a microdose (100 μg) of 14C-labeled drug (ZDV or tenofovir disoproxil fumarate (TDF)) with or without a standard unlabelled dose (300 mg) to healthy volunteers. Both the parent drug in plasma and the active metabolite, ZDV-triphosphate (ZDV-TP) or TFV-diphosphate (TFV-DP) in PBMCs and CD4+ cells were measured by AMS. Results The intracellular ZDV-TP concentration increased less than proportionally over the dose range studied (100 μg to 300 mg), while the intracellular TFV-DP PK were linear over the same dose range. ZDV-TP concentrations were lower in CD4+ cells versus total peripheral blood mononuclear cells (PBMCs), while TFV-DP concentrations were not different in CD4+ cells and PBMCs. Conclusion Our data were consistent with a rate-limiting step in the intracellular phosphorylation of ZDV but not TFV. AMS shows promise for predicting the PK of active intracellular metabolites of nucleosides, but nonlinearity of PK may be seen with some drugs. PMID:23187888

  20. Composite alginate hydrogel microparticulate delivery system of zidovudine hydrochloride based on counter ion induced aggregation

    PubMed Central

    Roy, Harekrishna; Rao, P. Venkateswar; Panda, Sanjay Kumar; Biswal, Asim Kumar; Parida, Kirti Ranjan; Dash, Jharana

    2014-01-01

    Aim: The present study deals with preparation of zidovudine loaded microparticle by counter ion induced aggregation method. During this study effect of polyacrylates and hypromellose polymers on release study were investigated. Materials and Methods: The ion induced aggregated alginate based microparticles were characterized for surface morphology, particle size analysis, drug entrapment study, in-vitro study, Fourier-transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC) study. Results and Discussion: The result showed Eudragit RL-100 (ERL) based formulations had smoother surface as well as their mean particle sizes were found greater compared with Eudragit RS-100 (ERS) microparticles. Furthermore, drug entrapments were found to be more in ERL formulae as compared with ERS. RL3 released 101.05% drug over a period of 8th h and followed Higuchi profile and Fickian diffusion. Moreover, data obtained illustrated that, higher amount of quaternary ammonium group, alkali value, and glass transition temperature may be possible reason for improving permeability of ERL based formulations. It was also noticed, hyroxypropyl methylcellulose (HPMC) K4M premium grade polymer sustained drug release more than HPMC K15M. In addition, drug-excipient interaction study was carried out by FTIR and DSC study. PMID:25298940

  1. Development of severe anaemia and changes in Haemoglobin (Hb) in a cohort of HIV infected Ugandan Adults receiving Zidovudine, Stavudine and Tenofovir containing antiretroviral regimens

    PubMed Central

    Parkes-Ratanshi, Rosalind; Katende, David; Levin, Jonathan; Wakeham, Katie; Heiner, Grosskurth; Kamali, Anatoli; Lalloo, David G

    2016-01-01

    Introduction Anaemia is a common problem in HIV in sub-Saharan Africa. We describe the contribution of ART regimen on the incidence of anaemia and changes in haemoglobin in Ugandan patients. Methods This study was nested in a prevention of cryptococcal disease trial (CRYPTOPRO; ISCRTN7648152). Patients received three different nucleoside reverse transcriptase inhibitor backbones in a non-randomised manner. Results Of 852 patients (161 on zidovudine, 628 on stavudine and 63 on tenofovir (all received lamuvidine), the risk of developing grade 4 anaemia was higher (aHR 2.7) for those taking zidovudine compared with stavudine. Those taking stavudine had a greater average increase in haemoglobin than those taking zidovudine (p=0.024) or tenofovir (p=0.014). Conclusion In this observational study zidovudine was associated with higher levels of severe anaemia than stavudine or tenofovir; those receiving zidovudine and tenofovir had smaller haemoglobin rises after ART initiation. We encourage publication of data from African cohorts using tenofovir. PMID:25425638

  2. Nanoencapsulation and characterization of zidovudine on poly(L-lactide) and poly(L-lactide)-poly(ethylene glycol)-blend nanoparticles.

    PubMed

    Mainardes, Rubiana Mara; Gremião, Maria Palmira Daflon

    2012-11-01

    In this work, the antiretroviral zidovudine was encapsulated on biodegradable poly(L-lactide) (PLA) or poly(L-lactide)-poly(ethylene glycol) (PLA-PEG)-blend nanoparticles by the double-emulsion solvent-evaporation method. The PLA-PEG blend was obtained by the physical mixture of the isolated polymers in organic solvent, whose PEG content ranges from 5 to 50 g in the blends. The physicochemical characteristics of the nanoparticles were evaluated applying particle-size and zeta-potential analyses, scanning electron microscopy, differential scanning calorimetry and Fourier-transform infrared spectroscopy. The release rate of zidovudine from the nanoparticles was investigated as well. The drug encapsulation efficiencies were around 50%, and the mean diameters of the nanoparticles were less than 400 nm. The PEG presence influenced all of the analyzed physicochemical parameters. The amount of drug released increases with the PEG presence in the blend. Therefore, the investigated nanoparticles are very promising carriers for zidovudine.

  3. Automated recognition of retroviral sequences in genomic data—RetroTector©

    PubMed Central

    Sperber, Göran O.; Airola, Tove; Jern, Patric; Blomberg, Jonas

    2007-01-01

    Eukaryotic genomes contain many endogenous retroviral sequences (ERVs). ERVs are often severely mutated, therefore difficult to detect. A platform independent (Java) program package, RetroTector© (ReTe), was constructed. It has three basic modules: (i) detection of candidate long terminal repeats (LTRs), (ii) detection of chains of conserved retroviral motifs fulfilling distance constraints and (iii) attempted reconstruction of original retroviral protein sequences, combining alignment, codon statistics and properties of protein ends. Other features are prediction of additional open reading frames, automated database collection, graphical presentation and automatic classification. ReTe favors elements >1000-bp long due to its dependence on order of and distances between retroviral fragments. It detects single or low-copy-number elements. ReTe assigned a ‘retroviral’ score of 890–2827 to 10 exogenous retroviruses from seven genera, and accurately predicted their genes. In a simulated model, ReTe was robust against mutational decay. The human genome was analyzed in 1–2 days on a LINUX cluster. Retroviral sequences were detected in divergent vertebrate genomes. Most ReTe detected chains were coincident with Repeatmasker output and the HERVd database. ReTe did not report most of the evolutionary old HERV-L related and MalR sequences, and is not yet tailored for single LTR detection. Nevertheless, ReTe rationally detects and annotates many retroviral sequences. PMID:17636050

  4. Comparison of anti-retroviral therapy treatment strategies in prevention of mother-to-child transmission in a teaching hospital in Ethiopia.

    PubMed

    Kumela, Kabaye; Amenu, Demisew; Chelkeba, Legese

    2015-01-01

    More than 90% of Human immunodeficiency virus (HIV) infection in children is acquired due to mother-to-child transmission, which is spreading during pregnancy, delivery or breastfeeding. To determine the effectiveness of highly active antiretroviral and short course antiretroviral regimens in prevention of mother-to-child transmission of HIV and associated factors Jimma University Specialized Hospital (JUSH). A hospital based retrospective cohort study was conducted on HIV infected pregnant mothers who gave birth and had follow up at anti-retroviral therapy (ART) clinic for at least 6 months during a time period paired with their infants. The primary and secondary outcomes were rate of infant infection by HIV at 6 weeks and 6 months respectively. The Chi-square was used for the comparison of categorical data multivariate logistic regression model was used to identify the determinants of early mother-to-child transmission of HIV at 6 weeks. Cox proportional hazard model was used to analyze factors that affect the 6 month HIV free survival of infants born to HIV infected mothers. A total of 180 mother infant pairs were considered for the final analysis, 90(50%) mothers received single dose nevirapine (sdNVP) designated as regimen-3, 67 (37.2%) mothers were on different types of ARV regimens commonly AZT + 3TC + NVP (regimen-1), while the rest 23 (12.8%) mothers were on short course dual regimen AZT + 3TC + sdNVP (regimen-2). Early mother-to-child transmission rate at 6 weeks for regimens 1, 2 and 3 were 5.9% (4/67), 8.6% (2/23), and 15.5% (14/90) respectively. The late cumulative mother-to-child transmission rate of HIV at 6 months regardless of regimen type was 15.5% (28/180). Postnatal transmission at 6 months was 28.5% (8/28) of infected children. Factors that were found to be associated with high risk of early mother-to-child transmission of HIV include duration of ARV regimen shorter than 2 months during pregnancy (OR=4.3, 95%CI =1.38-13.46), base line CD4 less

  5. Zidovudine, an anti-viral drug, resensitizes gemcitabine-resistant pancreatic cancer cells to gemcitabine by inhibition of the Akt-GSK3β-Snail pathway.

    PubMed

    Namba, T; Kodama, R; Moritomo, S; Hoshino, T; Mizushima, T

    2015-06-25

    Pancreatic cancer is one of the most difficult malignancies to treat owing to the rapid acquisition of resistance to chemotherapy. Gemcitabine, a first-line treatment for pancreatic cancer, prolongs patient survival by several months, and combination treatment with gemcitabine and other anti-cancer drugs in the clinic do not show any significant effects on overall survival. Thus, identification of a drug that resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine and a better understanding of the molecular mechanisms of gemcitabine resistance are critical to develop new therapeutic options for pancreatic cancer. Here, we report that zidovudine resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine as shown by screening a compound library, including clinical medicine, using gemcitabine-resistant cells. In analyzing the molecular mechanisms of zidovudine effects, we found that the epithelial-to-mesenchymal transition (EMT)-like phenotype and downregulation of human equilibrative nucleoside transporter 1 (hENT1) are essential for the acquisition of gemcitabine resistance, and zidovudine restored these changes. The chemical biology investigations also revealed that activation of the Akt-GSK3β-Snail1 pathway in resistant cells is a key signaling event for gemcitabine resistance, and zidovudine resensitized resistant cells to gemcitabine by inhibiting this activated pathway. Moreover, our in vivo study demonstrated that co-administration of zidovudine and gemcitabine strongly suppressed the formation of tumors by gemcitabine-resistant pancreatic cancer and prevented gemcitabine-sensitive pancreatic tumors from acquiring gemcitabine-resistant properties, inducing an EMT-like phenotype and downregulating hENT1 expression. These results suggested that co-treatment with zidovudine and gemcitabine may become a novel therapeutic strategy for pancreatic cancer by inhibiting chemoresistance-specific signaling.

  6. Zidovudine, an anti-viral drug, resensitizes gemcitabine-resistant pancreatic cancer cells to gemcitabine by inhibition of the Akt-GSK3β-Snail pathway

    PubMed Central

    Namba, T; Kodama, R; Moritomo, S; Hoshino, T; Mizushima, T

    2015-01-01

    Pancreatic cancer is one of the most difficult malignancies to treat owing to the rapid acquisition of resistance to chemotherapy. Gemcitabine, a first-line treatment for pancreatic cancer, prolongs patient survival by several months, and combination treatment with gemcitabine and other anti-cancer drugs in the clinic do not show any significant effects on overall survival. Thus, identification of a drug that resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine and a better understanding of the molecular mechanisms of gemcitabine resistance are critical to develop new therapeutic options for pancreatic cancer. Here, we report that zidovudine resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine as shown by screening a compound library, including clinical medicine, using gemcitabine-resistant cells. In analyzing the molecular mechanisms of zidovudine effects, we found that the epithelial-to-mesenchymal transition (EMT)-like phenotype and downregulation of human equilibrative nucleoside transporter 1 (hENT1) are essential for the acquisition of gemcitabine resistance, and zidovudine restored these changes. The chemical biology investigations also revealed that activation of the Akt-GSK3β-Snail1 pathway in resistant cells is a key signaling event for gemcitabine resistance, and zidovudine resensitized resistant cells to gemcitabine by inhibiting this activated pathway. Moreover, our in vivo study demonstrated that co-administration of zidovudine and gemcitabine strongly suppressed the formation of tumors by gemcitabine-resistant pancreatic cancer and prevented gemcitabine-sensitive pancreatic tumors from acquiring gemcitabine-resistant properties, inducing an EMT-like phenotype and downregulating hENT1 expression. These results suggested that co-treatment with zidovudine and gemcitabine may become a novel therapeutic strategy for pancreatic cancer by inhibiting chemoresistance-specific signaling. PMID:26111057

  7. Resistance detected by pyrosequencing following zidovudine monotherapy for prevention of HIV-1 mother-to-child-transmission.

    PubMed

    Olson, Scott C; Ngo-Giang-Huong, Nicole; Beck, Ingrid; Deng, Wenjie; Britto, Paula; Shapiro, David E; Bumgarner, Roger E; Mullins, James I; Van Dyke, Russell B; Jourdain, Gonzague; Frenkel, Lisa M

    2015-07-31

    To prevent mother-to-child-transmission of HIV-1, the 2010 WHO guidelines recommended prenatal zidovudine (ZDV) monotherapy (option A). To determine if ZDV monotherapy selects for HIV resistance in antiretroviral-naive women during pregnancy, specimens from 50 individuals were examined using pyrosequencing. ZDV-resistance mutations were detected at delivery in seven women (14%, 95% confidence interval 6.6-26.5%). These data raise the question whether women administered ZDV monotherapy for prevention of mother-to-child-transmission could have higher risk of virologic failure when later started on combination antiretroviral therapy, as has been demonstrated following single-dose nevirapine prophylaxis.

  8. Early virological response of zidovudine/lamivudine/abacavir for patients co-infected with HIV and tuberculosis in Uganda

    PubMed Central

    Srikantiah, Padmini; Walusimbi, Maria N.; Kayanja, H. Kose; Mayanja-Kizza, Harriet; Mugerwa, Roy D.; Lin, Royce; Charlebois, Edwin D.; Boom, W. Henry; Whalen, Christopher C.; Havlir, Diane V.

    2015-01-01

    Triple nucleoside reverse transcriptase inhibitors are recommended as an alternative regimen for HIV-infected patients undergoing tuberculosis treatment in resource-limited settings. Few data exist on the efficacy of such regimens in tuberculosis patients. In 34 tuberculosis/HIV-co-infected patients treated with zidovudine/lamivudine/abacavir, 76% achieved HIV RNA less than 50 copies/ml at 24 weeks. No cases of hypersensitivity or immune reconstitution syndrome were observed. These data support the continuing evaluation of nucleoside-based antiretroviral regimens as an alternative treatment for this population. PMID:17721107

  9. The NRTIs Lamivudine, Stavudine and Zidovudine Have Reduced HIV-1 Inhibitory Activity in Astrocytes

    PubMed Central

    Gray, Lachlan R.; Tachedjian, Gilda; Ellett, Anne M.; Roche, Michael J.; Cheng, Wan-Jung; Guillemin, Gilles J.; Brew, Bruce J.; Turville, Stuart G.; Wesselingh, Steve L.; Gorry, Paul R.; Churchill, Melissa J.

    2013-01-01

    HIV-1 establishes infection in astrocytes and macroage-lineage cells of the central nervous system (CNS). Certain antiretroviral drugs (ARVs) can penetrate the CNS, and are therefore often used in neurologically active combined antiretroviral therapy (Neuro-cART) regimens, but their relative activity in the different susceptible CNS cell populations is unknown. Here, we determined the HIV-1 inhibitory activity of CNS-penetrating ARVs in astrocytes and macrophage-lineage cells. Primary human fetal astrocytes (PFA) and the SVG human astrocyte cell line were used as in vitro models for astrocyte infection, and monocyte-derived macrophages (MDM) were used as an in vitro model for infection of macrophage-lineage cells. The CNS-penetrating ARVs tested were the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir (ABC), lamivudine (3TC), stavudine (d4T) and zidovudine (ZDV), the non-NRTIs efavirenz (EFV), etravirine (ETR) and nevirapine (NVP), and the integrase inhibitor raltegravir (RAL). Drug inhibition assays were performed using single-round HIV-1 entry assays with luciferase viruses pseudotyped with HIV-1 YU-2 envelope or vesicular stomatitis virus G protein (VSV-G). All the ARVs tested could effectively inhibit HIV-1 infection in macrophages, with EC90s below concentrations known to be achievable in the cerebral spinal fluid (CSF). Most of the ARVs had similar potency in astrocytes, however the NRTIs 3TC, d4T and ZDV had insufficient HIV-1 inhibitory activity in astrocytes, with EC90s 12-, 187- and 110-fold greater than achievable CSF concentrations, respectively. Our data suggest that 3TC, d4T and ZDV may not adequately target astrocyte infection in vivo, which has potential implications for their inclusion in Neuro-cART regimens. PMID:23614033

  10. Retroviral DNA Integration Directed by HIV Integration Protein in Vitro

    NASA Astrophysics Data System (ADS)

    Bushman, Frederic D.; Fujiwara, Tamio; Craigie, Robert

    1990-09-01

    Efficient retroviral growth requires integration of a DNA copy of the viral RNA genome into a chromosome of the host. As a first step in analyzing the mechanism of integration of human immunodeficiency virus (HIV) DNA, a cell-free system was established that models the integration reaction. The in vitro system depends on the HIV integration (IN) protein, which was partially purified from insect cells engineered to express IN protein in large quantities. Integration was detected in a biological assay that scores the insertion of a linear DNA containing HIV terminal sequences into a λ DNA target. Some integration products generated in this assay contained five-base pair duplications of the target DNA at the recombination junctions, a characteristic of HIV integration in vivo; the remaining products contained aberrant junctional sequences that may have been produced in a variation of the normal reaction. These results indicate that HIV IN protein is the only viral protein required to insert model HIV DNA sequences into a target DNA in vitro.

  11. Conformational study of a putative HLTV-1 retroviral protease inhibitor.

    PubMed

    Llido, S; d'Estaintot, B L; Dautant, A; Geoffre, S; Picard, P; Precigoux, G

    1993-05-01

    The crystal structure of prolyl-glutaminyl-valyl-statyl-alanyl-leucine (Pro-Gln-Val-Sta-Ala-Leu, C(32)H(57)N(7)0(9).5H(2)0, M(r) = 683.9 + 90.1), a putative HTLV-1 protease inhibitor based on one of the consensus retroviral protease cleavage sequences, and containing the statine residue [(4S,3S)-4-amino-3-hydroxy-6-methylheptanoic acid], has been determined by X-ray diffraction. The same molecule has been modelled in the active site of the HTLV-1 protease and both conformations have been compared. The peptide crystallizes as a pentahydrate in space group P2(1) with a = 10.874(2), b = 9.501(2), c = 21.062(5) A, beta = 103.68 (1) degrees, Z = 2, V= 2114.3 A(3), D(x) = 1.21 g cm(-3), micro = 8.02 cm(-1), T= 293 K, lambda(Cu Kalpha) = 1.5418 A. The structure has been refined to an R value of 0.070 for 2152 observed reflections. The peptide main chain can be described as extended and adopts the usual zigzag conformation from the prolyl to the statyl residue. The main difference in conformation between the individual observed and modelled molecules is located on the Sta, Ala and Leu residues with the main chain of the modelled molecule rotated by about 180 degrees as compared to the observed conformation in the crystal state.

  12. Epigenetics, drugs of abuse, and the retroviral promoter

    PubMed Central

    Shirazi, Jasmine; Shah, Sonia; Sagar, Divya; Nonnemacher, Michael R.; Wigdahl, Brian; Khan, Zafar K.; Jain, Pooja

    2013-01-01

    Drug abuse alone has been shown to cause epigenetic changes in brain tissue that have been shown to play roles in addictive behaviors. In conjunction with HIV-1 infection, it can cause epigenetic changes at the viral promoter that can result in altered gene expression, and exacerbate disease progression overall. This review entails an in-depth look at research conducted on the epigenetic effects of three of the most widely abused drugs (cannabinoids, opioids, and cocaine), with a particular focus on the mechanisms through which these drugs interact with HIV-1 infection at the viral promoter. Here we discuss the impact of this interplay on disease progression from the point of view of the nature of gene regulation at the level of chromatin accessibility, chromatin remodeling, and nucleosome repositioning. Given the importance of chromatin remodeling and DNA methylation in controlling the retroviral promoter, and the high susceptibility of the drug abusing population of individuals to HIV infection, it would be beneficial to understand the way in which the host genome is modified and regulated by drugs of abuse. PMID:24218017

  13. O-linked glycosylation of retroviral envelope gene products

    SciTech Connect

    Pinter, A.; Honnen, W.J. )

    1988-03-01

    Treatment of ({sup 3}H)glucosamine-labeled Friend mink cell focus-forming virus (FrMCF) gp70 with excess peptide:N-glycanase F (PNGase F) resulted in removal of the expected seven N-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-M{sub r} (49K) product. For ({sup 3}H)mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. Prior digestion of the PNGase F-treated gp70 with neuraminidase resulted in an addition size shift, and treatment with O-glycanase led to the removal of almost all of the PNGase F-resistant sugars. These results indicate that gp70 possesses sialic acid-containing O-linked oligosaccharides. Analysis of intracellular env precursors demonstrated that O-linked sugars were present in gPr90{sup env}, the polyprotein intermediate which contains complex sugars, but not in the primary translation product, gPr80{sup env}, and proteolytic digestion studies allowed localization of the O-linked carbohydrates to a 10K region near the center of the gp70 molecule. similar substituents were detected on the gp70s of ecotropic and xenotropic murine leukemia viruses and two subgroups of feline leukemia virus, indicting that O-linked glycosylation is a conserved feature of retroviral env proteins.

  14. The Effect of Life History on Retroviral Genome Invasions

    PubMed Central

    Kanda, Ravinder K.; Coulson, Tim

    2015-01-01

    Endogenous retroviruses (ERV), or the remnants of past retroviral infections that are no longer active, are found in the genomes of most vertebrates, typically constituting approximately 10% of the genome. In some vertebrates, particularly in shorter-lived species like rodents, it is not unusual to find active endogenous retroviruses. In longer-lived species, including humans where substantial effort has been invested in searching for active ERVs, it is unusual to find them; to date none have been found in humans. Presumably the chance of detecting an active ERV infection is a function of the length of an ERV epidemic. Intuitively, given that ERVs or signatures of past ERV infections are passed from parents to offspring, we might expect to detect more active ERVs in species with longer generation times, as it should take more years for an infection to run its course in longer than in shorter lived species. This means the observation of more active ERV infections in shorter compared to longer-lived species is paradoxical. We explore this paradox using a modeling approach to investigate factors that influence ERV epidemic length. Our simple epidemiological model may explain why we find evidence of active ERV infections in shorter rather than longer-lived species. PMID:25692467

  15. Neural stem cells as tools for understanding retroviral neuropathogenesis.

    PubMed

    Lynch, W P; Portis, J L

    2000-06-05

    The discovery within the past decade that neural stem cells (NSCs) from the developing and adult mammalian brain can be propagated, cloned, and genetically manipulated ex vivo for ultimate transfer back into the CNS has opened the door to a novel means for modifying the CNS environment for experimental and therapeutic purposes. While a great deal of interest has been focused on the properties and promise of this new technology, especially in regard to cellular replacement and gene therapy, this minireview will focus on the recent use of NSCs to study the neuropathogenesis of the murine oncornaviruses. In brief, the use of this NSC-based approach has provided a means for selective reconstitution within the brain, of specific retroviral life cycle events, in order to consider their contribution to the induction of neurodegeneration. Furthermore, by virtue of their ability to disseminate virus within the brain, NSCs have provided a reliable means for assessing the true neurovirulence potential of murine oncornaviruses by directly circumventing a restriction to virus entry into the CNS. Importantly, these experiments have demonstrated that the neurovirulence of oncornaviruses requires late virus life cycle events occurring specifically within microglia, the resident macrophages of the brain. This initial application of NSC biology to the analysis of oncornavirus-CNS interactions may serve as an example for how other questions in viral neuropathogenesis might be addressed in the future.

  16. Retroviral particles in neoplasms of Burmese pythons (Python molurus bivittatus).

    PubMed

    Chandra, A M; Jacobson, E R; Munn, R J

    2001-09-01

    Neoplastic diseases associated with retroviruses were diagnosed in four Burmese pythons (Python molurus bivattatus) from a single collection. Snake No. 1 was a 7-year-old female with recurrent undifferentiated mesenchymal round cell tumor (lymphosarcoma) of the oral cavity. At necropsy, similar neoplastic masses were evident in the uterus and ovary, and there was diffuse involvement of the spleen. Snake No. 2 was a 4.5-year-old female that was euthanatized because of complications following resection of a segmental colonic adenocarcinoma. Snake No. 3 was a 5-year-old female that was euthanatized because of a large transitional cell carcinoma of the right kidney. Snake No. 4 was a 19-year-old female that was euthanatized following recurrence of an intermandibular fibrosarcoma. Ultrastructural examination revealed few to numerous extracellular and intracellular (intravacuolar) type C-like retroviral particles in all tumors. Tumors were about 90-95 nm in diameter, with an electron-dense core and bilaminar external membrane. The relationship of the intraneoplastic viral particles to the etiology of the tumors is uncertain.

  17. Toward global standards for comparator pharmaceutical products: case studies of amoxicillin, metronidazole, and zidovudine in the Americas.

    PubMed

    Löbenberg, Raimar; Chacra, Nadia B; Stippler, Erika S; Shah, Vinod P; DeStefano, Anthony J; Hauck, Walter W; Williams, Roger L

    2012-09-01

    This study compared in vitro dissolution characteristics and other quality measures of different amoxicillin, metronidazole, and zidovudine products purchased in the Americas to a comparator pharmaceutical product (CPP). These three drugs are classified as Biopharmaceutics Classification System Class I drugs with the possibility that dissolution findings might be used to document bioequivalence. All investigated zidovudine products were found to be in vitro equivalent to the CPP. Only 3 of 12 tested amoxicillin products were found to be in vitro equivalent to the CPP. None of the tested metronidazole products were in vitro equivalent to the CPP. These findings suggest but do not confirm bioinequivalence where in vitro comparisons failed, given that an in vivo blood level study might have confirmed bioequivalence. At times, identifying a CPP in one of the selected markets proved difficult. The study demonstrates that products sold across national markets may not be bioequivalent. When coupled with the challenge of identifying a CPP in different countries, the results of this study suggest the value of an international CPP as well as increased use of BCS approaches as means of either documenting bioequivalence or signaling the need for further in vivo studies. Because of increased movement of medicines across national borders, practitioners and patients would benefit from these approaches.

  18. Zidovudine-loaded PLA and PLA-PEG blend nanoparticles: influence of polymer type on phagocytic uptake by polymorphonuclear cells.

    PubMed

    Mainardes, Rubiana Mara; Gremião, Maria Palmira Daflon; Brunetti, Iguatemy Lourenço; da Fonseca, Luiz Marcos; Khalil, Najeh Maissar

    2009-01-01

    Mononuclear (macrophages) and polymorphonuclear leucocytes cells play an important role in the immunopathogenesis of acquired immunodeficiency syndrome. Zidovudine is a broad-spectrum drug used in current antiretroviral therapy. The development of controlled drug delivery systems for the treatment of chronic diseases is of great interest since these systems can act as vectors, carrying the drug only to the target, and the adverse effects can be reduced. In this study, PLA and PLA/PEG blend nanoparticles containing zidovudine were developed and their uptake by polymorphonuclear leucocytes were studied in vitro. The influence of polymer type on particle size, Zeta potential and particle uptake by polymorphonuclear leucocytes was investigated. The cells were isolated from rat peritoneal exudate and their activation by nanoparticles was measured by luminol-dependent chemiluminescence and microscopical analysis. The PEG in the blend modified the Zeta potential suggested the formation of a PEG coat on the particle surface. The phagocytosis depended on the PEG and its ratio in the blend, the results showed that the PLA nanoparticles were more efficiently phagocytosed than PLA/PEG blends. The blend with the highest PEG proportion did not prevent phagocytosis, indicating that the steric effect of PEG was concentration dependent. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

  19. Efficacy of zidovudine and human immunodeficiency virus (HIV) hyperimmune immunoglobulin for reducing perinatal HIV transmission from HIV-infected women with advanced disease: results of Pediatric AIDS Clinical Trials Group protocol 185.

    PubMed

    Stiehm, E R; Lambert, J S; Mofenson, L M; Bethel, J; Whitehouse, J; Nugent, R; Moye, J; Glenn Fowler, M; Mathieson, B J; Reichelderfer, P; Nemo, G J; Korelitz, J; Meyer, W A; Sapan, C V; Jimenez, E; Gandia, J; Scott, G; O'Sullivan, M J; Kovacs, A; Stek, A; Shearer, W T; Hammill, H

    1999-03-01

    Pediatric AIDS Clinical Trials Group protocol 185 evaluated whether zidovudine combined with human immunodeficiency virus (HIV) hyperimmune immunoglobulin (HIVIG) infusions administered monthly during pregnancy and to the neonate at birth would significantly lower perinatal HIV transmission compared with treatment with zidovudine and intravenous immunoglobulin (IVIG) without HIV antibody. Subjects had baseline CD4 cell counts zidovudine for maternal health (24% received zidovudine before pregnancy). Transmission was associated with lower maternal baseline CD4 cell count (odds ratio, 1.58 per 100-cell decrement; P=.005; 10.0% vs. 3.6% transmission for count <200 vs. >/=200/microL) but not with time of zidovudine initiation (5.6% vs. 4.8% if started before vs. during pregnancy; P=. 75). The Kaplan-Meier transmission rate for HIVIG recipients was 4. 1% (95% confidence interval, 1.5%-6.7%) and for IVIG recipients was 6.0% (2.8%-9.1%) (P=.36). The unexpectedly low transmission confirmed that zidovudine prophylaxis is highly effective, even for women with advanced HIV disease and prior zidovudine therapy, although it limited the study's ability to address whether passive immunization diminishes perinatal transmission.

  20. Retroviral nucleocapsid proteins possess potent nucleic acid strand renaturation activity.

    PubMed Central

    Dib-Hajj, F.; Khan, R.; Giedroc, D. P.

    1993-01-01

    The nucleocapsid protein (NC) is the major genomic RNA binding protein that plays integral roles in the structure and replication of all animal retroviruses. In this report, select biochemical properties of recombinant Mason-Pfizer monkey virus (MPMV) and HIV-1 NCs are compared. Evidence is presented that two types of saturated Zn2 NC-polynucleotide complexes can be formed under conditions of low [NaCl] that differ in apparent site-size (n = 8 vs. n = 14). The formation of one or the other complex appears dependent on the molar ratio of NC to RNA nucleotide with the putative low site-size mode apparently predominating under conditions of protein excess. Both MPMV and HIV-1 NCs kinetically facilitate the renaturation of two complementary DNA strands, suggesting that this is a general property of retroviral NCs. NC proteins increase the second-order rate constant for renaturation of a 149-bp DNA fragment by more than four orders of magnitude over that obtained in the absence of protein at 37 degrees C. The protein-assisted rate is 100-200-fold faster than that obtained at 68 degrees C, 1 M NaCl, solution conditions considered to be optimal for strand renaturation. Provided that sufficient NC is present to coat all strands, the presence of 400-1,000-fold excess nonhomologous DNA does not greatly affect the reaction rate. The HIV-1 NC-mediated renaturation reaction functions stoichiometrically, requiring a saturated strand of DNA nucleotide:NC ratio of about 7-8, rather than 14. Under conditions of less protein, the rate acceleration is not realized. The finding of significant nucleic acid strand renaturation activity may have important implications for various events of reverse transcription particularly in initiation and cDNA strand transfer. PMID:8443601

  1. Retroviral expression of connexins in embryonic chick lens.

    PubMed

    Jiang, J X; Goodenough, D A

    1998-03-01

    To develop an in vivo model system in which exogenous proteins can be expressed in embryonic chick lens and to further understand the function of connexin-mediated gap junction intercellular communication in lens cell biology. RCAS(A) is a replication-competent chicken retrovirus that infects dividing cells. Retroviral constructs were prepared containing alkaline phosphatase (AP) and FLAG-tagged connexins. Chick lenses were infected in situ by injecting virus into the lumen of lens vesicles at stage 18, cultures were taken at various periods. The lenses were then dissected, and the expressed proteins were visualized by AP histochemical examination and immunostaining. Twenty-four hours after infection, alkaline phosphatase could be seen in epithelia and fibers. As lens fiber maturation progressed, however, the alkaline phosphatase staining was lost as the fibers matured, presumably because of the proteolytic removal of the enzyme. By 72 hours, alkaline phosphatase staining could still be observed in epithelial cells and in differentiating fibers in the bow region but not in the mature lens fibers. FLAG-tagged exogenous lens connexins were also abundantly expressed by viral infection. The exogenous connexins were localized at the cell surfaces in junctional maculae and showed the same cell-type specific distribution as that of their endogenous connexin counterparts. An in vivo model system has been developed in the chick that provides opportunities to study the expression of wild-type and mutant proteins during lens differentiation. Expression of wild-type connexins has revealed that the characteristic distribution of the three different lens connexins is maintained even when expression is driven by a viral promoter.

  2. Larger Mammalian Body Size Leads to Lower Retroviral Activity

    PubMed Central

    Katzourakis, Aris; Magiorkinis, Gkikas; Lim, Aaron G.; Gupta, Sunetra; Belshaw, Robert; Gifford, Robert

    2014-01-01

    Retroviruses have been infecting mammals for at least 100 million years, leaving descendants in host genomes known as endogenous retroviruses (ERVs). The abundance of ERVs is partly determined by their mode of replication, but it has also been suggested that host life history traits could enhance or suppress their activity. We show that larger bodied species have lower levels of ERV activity by reconstructing the rate of ERV integration across 38 mammalian species. Body size explains 37% of the variance in ERV integration rate over the last 10 million years, controlling for the effect of confounding due to other life history traits. Furthermore, 68% of the variance in the mean age of ERVs per genome can also be explained by body size. These results indicate that body size limits the number of recently replicating ERVs due to their detrimental effects on their host. To comprehend the possible mechanistic links between body size and ERV integration we built a mathematical model, which shows that ERV abundance is favored by lower body size and higher horizontal transmission rates. We argue that because retroviral integration is tumorigenic, the negative correlation between body size and ERV numbers results from the necessity to reduce the risk of cancer, under the assumption that this risk scales positively with body size. Our model also fits the empirical observation that the lifetime risk of cancer is relatively invariant among mammals regardless of their body size, known as Peto's paradox, and indicates that larger bodied mammals may have evolved mechanisms to limit ERV activity. PMID:25033295

  3. Myd88 Is Required for an Antibody Response to Retroviral Infection

    PubMed Central

    Browne, Edward P.; Littman, Dan R.

    2009-01-01

    Although retroviruses have been extensively studied for many years, basic questions about how retroviral infections are detected by the immune system and which innate pathways are required for the generation of immune responses remain unanswered. Defining these pathways and how they contribute to the anti-retroviral immune responses would assist in the development of more effective vaccines for retroviral pathogens such as HIV. We have investigated the roles played by CD11c+ dendritic cells (DCs) and by Toll-like receptor (TLR) signaling pathways in the generation of an anti-retroviral immune response against a mouse retroviral pathogen, Friend murine leukemia virus (F-MLV). Specific deletion of DCs during F-MLV infection caused a significant increase in viral titers at 14 days post-infection, indicating the importance of DCs in immune control of the infection. Similarly, Myd88 knockout mice failed to control F-MLV, and sustained high viral titers (107 foci/spleen) for several months after infection. Strikingly, both DC-depleted mice and Myd88 knockout mice exhibited only a partial reduction of CD8+ T cell responses, while the IgG antibody response to F-MLV was completely lost. Furthermore, passive transfer of immune serum from wild-type mice to Myd88 knockout mice rescued control of F-MLV. These results identify TLR signaling and CD11c+ DCs as playing critical roles in the humoral response to retroviruses. PMID:19214214

  4. Closed hollow-fiber bioreactor: a new approach to retroviral vector production.

    PubMed

    Pan, D; Whitley, C B

    1999-01-01

    The ability to obtain high-titer and large quantities of retroviral vector production in a 'closed' system would have profound implications in clinical and experimental gene therapy. We studied the cell growth and vector production of three retroviral packaging cell lines in a variety of conditions using hollow-fiber bioreactors designed as an 'artificial capillary system' (ACS) and enhanced with the application of a hermetically sealing device for sterile welding of connecting plastic tubings. Vector titer, fetal bovine serum (FBS) concentration, volume and the duration of productivity were assessed to optimize vector production. In this pilot study, we observed that retroviral vector production (frozen-and-thawed) from cultures containing as low as 2.5% FBS yielded titers up to 2.2 x 10(7) cfu/ml, 14.4-fold higher than titers obtained from control dish cultures. Up to 3 liters of vector supernatant were generated during a 2-month large-scale production run. There was a potential to double this volume of higher-titer supernatant by increasing the frequency of harvest. It seemed that a lower metabolic rate (i.e. lactate production) in the packaging cell culture was associated with higher vector producing ability. These data demonstrated the feasibility of producing retroviral vector with enhanced titers and clinically useful quantities in a 'closed' ACS. Thus a new approach for large-scale retroviral vector production is developed.

  5. A prospective study of haematological changes after switching from stavudine to zidovudine-based antiretroviral treatment in HIV-infected children.

    PubMed

    Singh, Archana; Hemal, Alok; Agarwal, Sheetal; Dubey, N K; Buxi, Gurdeep

    2016-11-01

    Long-term use of stavudine is associated with a high incidence of lipodystrophy, warranting its substitution with zidovudine in first-line antiretroviral therapy (ART) regimens. In a prospective observational study, we determined the spectrum and severity of haematological changes after switching from stavudine- to zidovudine-based ART in Indian children aged 2-18 years who had received a stavudine-based ART regimen for at least 48 weeks. They were followed for 48 weeks for changes in haematological parameters and CD4 cell counts after switching to zidovudine. Of the 60 children analysed, 45 (75%) showed a significant fall in Hb (>1 g/dl). A majority developed grade 1 anaemia (14 [31%]) while only three (6%) developed grade 4 anaemia. The lowest Hb was recorded between 12 and 16 weeks with spontaneous improvement noticed after 28 weeks. A significant drop in absolute neutrophil count (5067 cells/mm(3) to 3625 cells/mm(3); p = 0.004) was also observed but none developed severe neutropenia. No significant changes were observed in platelet and CD4 cell counts. Since the incidence of severe drug toxicity was low with zidovudine and the majority of children recovered without intervention, drug toxicity should not preclude its routine use in poor countries.

  6. Recovery from lipodystrophy in HIV-infected children after substitution of stavudine with zidovudine in a non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy.

    PubMed

    Aurpibul, Linda; Puthanakit, Thanyawee; Taejaroenkul, Sineenart; Sirisanthana, Thira; Sirisanthana, Virat

    2012-04-01

    Substitution of stavudine with zidovudine may lead to recovery from lipodystrophy (LD) in HIV-infected children. We prospectively followed HIV-infected children enrolled in an earlier LD study conducted between 2002 and 2004 at Chiang Mai University Hospital in northern Thailand. In 2006, stavudine was substituted with zidovudine. All children were evaluated by a clinical LD checklist modified from that of the European Pediatric LD study group together with waist/hip measurement at baseline and 24, 48, 72, and 96 weeks after substitution. The waist-to-hip ratios were converted to age- and sex-adjusted z scores based on normal ranges in healthy Thai children. Forty-five lipodystrophic children with 36 episodes of lipohypertrophy and 22 episodes of lipoatrophy were enrolled. By weeks 48 and 96 after substitution, 40% and 47% of lipohypertrophy resolved, whereas 59% and 73% of lipoatrophy resolved, respectively. The rate of resolution of lipoatrophy was higher than that of lipohypertrophy at 48 weeks after substitution and thereafter. Ninety-six weeks after changing to zidovudine therapy, 8 children still had LD (1 with both lipoatrophy and lipohypertrophy, 7 with lipohypertrophy). No clinically significant hematologic adverse event was observed. Substitution of stavudine with zidovudine resulted in decreased severity or resolution of LD among HIV-infected children and adolescents.

  7. Oligonucleotide Ligation Assay for Detecting Mutations in the Human Immunodeficiency Virus Type 1 pol Gene That Are Associated with Resistance to Zidovudine, Didanosine, and Lamivudine

    PubMed Central

    Edelstein, Reva E.; Nickerson, Deborah A.; Tobe, Vincent O.; Manns-Arcuino, Laura A.; Frenkel, Lisa M.

    1998-01-01

    This report describes the detection of mutations in the pol gene of human immunodeficiency virus type 1 associated with resistance to zidovudine, didanosine, and lamivudine by genotyping by an oligonucleotide ligation assay specific codons in the pol gene amplified by PCR. Our studies demonstrate the sensitivity, simplicity, and specificity of this genotyping system. PMID:9466779

  8. Mutational Analysis of the Mitochondrial tRNA Genes and Flanking Regions in Umbilical Cord Tissue from Uninfected Infants Receiving AZT-Based Therapies for Prophylaxis of HIV-1

    PubMed Central

    Torres, Salina M.; Walker, Dale M.; McCash, Consuelo L.; Carter, Meghan M.; Ming, Jessica; Cordova, Edmund M.; Pons, Rachel M.; Cook, Dennis L.; Seilkop, Steven K.; Copeland, William C.; Walker, Vernon E.

    2011-01-01

    A sensitive vertical denaturing gradient gel electrophoresis (DGGE) method, using 13 unipolar psoralen-clamped PCR primer pairs, was developed for detecting sequence variants in the 22 tRNA genes and flanking regions (together spanning ~21%) of the human mitochondrial genome. A study was conducted to determine (i) if mitochondrial DNA (mtDNA) polymorphisms and/or mutations were detectable in healthy newborns and (ii) if prepartum 3′-azido-2′,3′-dideoxythymidine (AZT) based HIV-1 prophylaxis was associated with significant increases in mtDNA mutations and changes in the degree of heteroplasmy of sequence variants in uninfected infants born to HIV-1-infected mothers. DGGE analysis of umbilical cord tissue (where vascular endothelium and smooth muscle cells are the major source of mtDNA) showed that mtDNA sequence variants were significantly elevated by threefold in AZT-treated infants compared with unexposed controls (P < 0.001), with 24 changes observed in 19/52 (37%) treated newborns (averaging 0.46 changes/subject) versus only eight changes found in 7/55 (13%) unexposed newborns (averaging 0.15 changes/subject). Six distinct sequence variants occurring in unexposed controls were predominately synonymous and homoplasmic, representing previously reported polymorphisms. Uninfected infants exposed to a combination of AZT and 2′,3′-dideoxy-3′-thiacytidine and “maternal HIV-1” had a significant shift in the spectrum of mutations (P = 0.04) driven by increases in nonsynonymous heteroplasmic sequence variants at polymorphic sites (10 distinct variants) and novel sites (four distinct variants). While the weight of evidence suggests that prepartum AZT-based prophylaxis produces mtDNA mutations, additional research is needed to determine the degree to which fetal responses to maternal HIV-1 infection, in the absence of antiretroviral treatment, contribute to prenatal mtDNA mutagenesis. PMID:19031409

  9. Safety of zidovudine/lamivudine scored tablets in children with HIV infection in Europe and Thailand.

    PubMed

    2017-04-01

    Zidovudine (ZDV) has been associated with risk of haematological toxicity. Safety data from clinical trials is generally limited to 48 weeks. We assessed the short- and mid-term toxicity of ZDV/lamivudine (3TC) fixed-dose combination scored tablets in HIV-infected children followed in the European Pregnancy and Paediatric HIV Cohort Collaboration (EPPICC) network. Fourteen cohorts provided data on patients <18 years of age taking ZDV/3TC scored tablets between 2008 and 2012. Rates of Division of AIDS (DAIDS) grade ≥3 laboratory adverse events (AEs) for hepatobiliary and haematological disorders were estimated by duration on drug (<12, 12-24, >24 months). Clinical adverse events and reasons for tablet discontinuation were described. Of 541 patients on ZDV/3TC, 388 (72%) had weight and dose data available, of whom 350 (90%) weighed ≥14 kg and were eligible for tablet use; 161 (41%) were aged <10 years on an approved dose, 189 (49%) aged ≥10 years on an approved dose, and 30 (8%) were on an unapproved dose. Median age at ZDV/3TC start was 10 years, and 79% had taken ART previously (60% had prior exposure to ZDV/3TC). Overall rates of grade ≥3 AEs for absolute neutrophil counts, bilirubin, haemoglobin, platelet counts, white blood cell counts (WBC), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were ≤2/100 person years (PY) for patients taking approved doses. Two hundred thirty-three (43%) patients were not on ZDV/3TC tablets at most recent follow-up; a small number (17 (7%)) discontinued due to AEs (17 (7%)), and the most common reason for discontinuation was treatment simplification (73 (31%)). Scored ZDV/3TC tablets, both approved and taken off-label, appear to be well tolerated with few side effects. Few patients discontinued treatment due to toxicity. As ZDV/3TC tablets are taken with other antiretrovirals, it is difficult to infer association between toxicities and specific agents, highlighting the importance of widening

  10. The accumulation and metabolism of zidovudine in 3T3-F442A pre-adipocytes

    PubMed Central

    Janneh, Omar; Owen, Andrew; Bray, Patrick G; Back, David J; Pirmohamed, Munir

    2010-01-01

    Background and purpose: Cultured pre-adipocytes accumulate and metabolize zidovudine (ZDV), but its mode of accumulation into these cells is unclear. We investigated the mode of accumulation of [3H]-ZDV, and the impact of changes in external pH and modulators of drug transporters on its accumulation and metabolism. Experimental approach: The initial rate and steady-state accumulation of [3H]-ZDV were measured in 3T3-F442A cells. P-glycoprotein (P-gp) expression was detected by Western blotting. External pH was varied, and modulators of intracellular pH and drug transporters were used to study the mode of accumulation of ZDV. Phosphorylated ZDV metabolites were detected by high-performance liquid chromatography. Key results: Intracellular accumulation of ZDV was rapid, reaching equilibrium within 20 min; nigericin increased accumulation by 1.9-fold, but this did not alter the generation of ZDV mono-, di- and triphosphate. The accumulation and metabolism were pH dependent, being maximal at pH 7.4 and least at pH 5.1. Monensin, carbonyl cyanide p-trifluoromethoxy) phenyl hydrazone, brefeldin A, bafilomycin A1 and concanamycin A increased accumulation; 2-deoxyglucose, dipyridamole, thymidine and tetraphenylphosphonium inhibited accumulation. The accumulation was saturable; the derived Kd and capacity of binding were 250 nmol per 106 cells and 265 nM respectively. 3T3-F442A cells express P-gp; inhibitors of P-gp (XR9576 and verapamil), P-gp/BCRP (GF120918), multidrug resistance protein (MRP) (MK571) and MRP/OATP (probenecid) increased the accumulation of ZDV. Saquinavir, ritonavir, amprenavir and lopinavir increased accumulation. Conclusions and implications: The accumulation of ZDV in 3T3-F442A cells was rapid, energy dependent, saturable and pH sensitive. Western blot analysis showed that 3T3-F442A cells express P-gp, and direct inhibition assays suggest that ZDV is a substrate of P-gp and MRP. PMID:20015290

  11. Abacavir, zidovudine, or stavudine as paediatric tablets for African HIV-infected children (CHAPAS-3): an open-label, parallel-group, randomised controlled trial.

    PubMed

    Mulenga, Veronica; Musiime, Victor; Kekitiinwa, Adeodata; Cook, Adrian D; Abongomera, George; Kenny, Julia; Chabala, Chisala; Mirembe, Grace; Asiimwe, Alice; Owen-Powell, Ellen; Burger, David; McIlleron, Helen; Klein, Nigel; Chintu, Chifumbe; Thomason, Margaret J; Kityo, Cissy; Walker, A Sarah; Gibb, Diana M

    2016-02-01

    WHO 2013 guidelines recommend universal treatment for HIV-infected children younger than 5 years. No paediatric trials have compared nucleoside reverse-transcriptase inhibitors (NRTIs) in first-line antiretroviral therapy (ART) in Africa, where most HIV-infected children live. We aimed to compare stavudine, zidovudine, or abacavir as dual or triple fixed-dose-combination paediatric tablets with lamivudine and nevirapine or efavirenz. In this open-label, parallel-group, randomised trial (CHAPAS-3), we enrolled children from one centre in Zambia and three in Uganda who were previously untreated (ART naive) or on stavudine for more than 2 years with viral load less than 50 copies per mL (ART experienced). Computer-generated randomisation tables were incorporated securely within the database. The primary endpoint was grade 2-4 clinical or grade 3/4 laboratory adverse events. Analysis was intention to treat. This trial is registered with the ISRCTN Registry number, 69078957. Between Nov 8, 2010, and Dec 28, 2011, 480 children were randomised: 156 to stavudine, 159 to zidovudine, and 165 to abacavir. After two were excluded due to randomisation error, 156 children were analysed in the stavudine group, 158 in the zidovudine group, and 164 in the abacavir group, and followed for median 2·3 years (5% lost to follow-up). 365 (76%) were ART naive (median age 2·6 years vs 6·2 years in ART experienced). 917 grade 2-4 clinical or grade 3/4 laboratory adverse events (835 clinical [634 grade 2]; 40 laboratory) occurred in 104 (67%) children on stavudine, 103 (65%) on zidovudine, and 105 (64%), on abacavir (p=0·63; zidovudine vs stavudine: hazard ratio [HR] 0·99 [95% CI 0·75-1·29]; abacavir vs stavudine: HR 0·88 [0·67-1·15]). At 48 weeks, 98 (85%), 81 (80%) and 95 (81%) ART-naive children in the stavudine, zidovudine, and abacavir groups, respectively, had viral load less than 400 copies per mL (p=0·58); most ART-experienced children maintained suppression (p=1·00). All

  12. Abacavir, zidovudine, or stavudine as paediatric tablets for African HIV-infected children (CHAPAS-3): an open-label, parallel-group, randomised controlled trial

    PubMed Central

    Mulenga, Veronica; Musiime, Victor; Kekitiinwa, Adeodata; Cook, Adrian D; Abongomera, George; Kenny, Julia; Chabala, Chisala; Mirembe, Grace; Asiimwe, Alice; Owen-Powell, Ellen; Burger, David; McIlleron, Helen; Klein, Nigel; Chintu, Chifumbe; Thomason, Margaret J; Kityo, Cissy; Walker, A Sarah; Gibb, Diana M

    2016-01-01

    Summary Background WHO 2013 guidelines recommend universal treatment for HIV-infected children younger than 5 years. No paediatric trials have compared nucleoside reverse-transcriptase inhibitors (NRTIs) in first-line antiretroviral therapy (ART) in Africa, where most HIV-infected children live. We aimed to compare stavudine, zidovudine, or abacavir as dual or triple fixed-dose-combination paediatric tablets with lamivudine and nevirapine or efavirenz. Methods In this open-label, parallel-group, randomised trial (CHAPAS-3), we enrolled children from one centre in Zambia and three in Uganda who were previously untreated (ART naive) or on stavudine for more than 2 years with viral load less than 50 copies per mL (ART experienced). Computer-generated randomisation tables were incorporated securely within the database. The primary endpoint was grade 2–4 clinical or grade 3/4 laboratory adverse events. Analysis was intention to treat. This trial is registered with the ISRCTN Registry number, 69078957. Findings Between Nov 8, 2010, and Dec 28, 2011, 480 children were randomised: 156 to stavudine, 159 to zidovudine, and 165 to abacavir. After two were excluded due to randomisation error, 156 children were analysed in the stavudine group, 158 in the zidovudine group, and 164 in the abacavir group, and followed for median 2·3 years (5% lost to follow-up). 365 (76%) were ART naive (median age 2·6 years vs 6·2 years in ART experienced). 917 grade 2–4 clinical or grade 3/4 laboratory adverse events (835 clinical [634 grade 2]; 40 laboratory) occurred in 104 (67%) children on stavudine, 103 (65%) on zidovudine, and 105 (64%), on abacavir (p=0·63; zidovudine vs stavudine: hazard ratio [HR] 0·99 [95% CI 0·75–1·29]; abacavir vs stavudine: HR 0·88 [0·67–1·15]). At 48 weeks, 98 (85%), 81 (80%) and 95 (81%) ART-naive children in the stavudine, zidovudine, and abacavir groups, respectively, had viral load less than 400 copies per mL (p=0·58); most ART

  13. Maternal anaemia and duration of zidovudine in antiretroviral regimens for preventing mother-to-child transmission: a randomized trial in three African countries.

    PubMed

    Sartorius, Benn K D; Chersich, Matthew F; Mwaura, Mary; Meda, Nicolas; Temmerman, Marleen; Newell, Marie Louise; Farley, Timothy M M; Luchters, Stanley

    2013-11-06

    Although substantiated by little evidence, concerns about zidovudine-related anaemia in pregnancy have influenced antiretroviral (ARV) regimen choice for preventing mother-to-child transmission of HIV-1, especially in settings where anaemia is common. Eligible HIV-infected pregnant women in Burkina Faso, Kenya and South Africa were followed from 28 weeks of pregnancy until 12-24 months after delivery (n = 1070). Women with a CD4 count of 200-500 cells/mm(3) and gestational age 28-36 weeks were randomly assigned to zidovudine-containing triple-ARV prophylaxis continued during breastfeeding up to 6-months, or to zidovudine during pregnancy plus single-dose nevirapine (sd-NVP) at labour. Additionally, two cohorts were established, women with CD4 counts: <200 cells/mm(3) initiated antiretroviral therapy, and >500 cells/mm(3) received zidovudine during pregnancy plus sd-NVP at labour. Mild (haemoglobin 8.0-10.9 g/dl) and severe anaemia (haemoglobin < 8.0 g/dl) occurrence were assessed across study arms, using Kaplan-Meier and multivariable Cox proportional hazards models. At enrolment (corresponded to a median 32 weeks gestation), median haemoglobin was 10.3 g/dl (IQR = 9.2-11.1). Severe anaemia occurred subsequently in 194 (18.1%) women, mostly in those with low baseline haemoglobin, lowest socio-economic category, advanced HIV disease, prolonged breastfeeding (≥ 6 months) and shorter ARV exposure. Severe anaemia incidence was similar in the randomized arms (equivalence P-value = 0.32). After 1-2 months of ARV's, severe anaemia was significantly reduced in all groups, though remained highest in the low CD4 cohort. Severe anaemia occurs at a similar rate in women receiving longer triple zidovudine-containing regimens or shorter prophylaxis. Pregnant women with pre-existing anaemia and advanced HIV disease require close monitoring. ISRCTN71468401.

  14. The combination of arsenic, interferon-alpha, and zidovudine restores an “immunocompetent-like” cytokine expression profile in patients with adult T-cell leukemia lymphoma

    PubMed Central

    2013-01-01

    Background HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN. Results Here we assessed Th1/Th2/Treg cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. ATL patients at diagnosis displayed a Treg/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4+CD25+ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4+CD25+ cells. Finally, IL-10 transcript level negatively correlated with clinical response at Day 30. Conclusions The observed shift from a Treg/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections. PMID:23962110

  15. Addition of 7 Days of Zidovudine plus Lamivudine to Peripartum Single-Dose Nevirapine Effectively Reduces Nevirapine Resistance Postpartum in HIV-Infected Mothers in Malawi

    PubMed Central

    Farr, Sherry L.; Nelson, Julie A.E.; Ng’ombe, Thokozani J.; Kourtis, Athena P.; Chasela, Charles; Johnson, Jeffrey A.; Kashuba, Angela D.M.; Tegha, Gerald L.; Wiener, Jeffrey; Eron, Joseph J.; Banda, Harriet N.; Mpaso, Mwanangwa; Lipscomb, Jonathan; Matiki, Chrissie; Fiscus, Susan A.; Jamieson, Denise J.; van der Horst, Charles

    2010-01-01

    Background We assessed whether 7 days of zidovudine+lamivudine postpartum with single-dose nevirapine at labor decreases nevirapine resistance in HIV-infected women in Malawi. Methods HIV-infected pregnant women receiving intrapartum single-dose nevirapine and 7 days of zidovudine+lamivudine (n=132), and women receiving intrapartum single-dose nevirapine alone (n=66) were followed from an antenatal visit through 6 weeks postpartum. Plasma specimens at 2 and 6 weeks postpartum were tested for genotypic resistance to nevirapine by population sequencing and sensitive real-time PCR. Poisson regression was used to determine predictors of postpartum nevirapine resistance. Results Median HIV RNA was similar at entry (4.27 log vs. 4.35 log, p=0.87), differed at 2 weeks postpartum (2.67 log vs. 3.58 log, p<0.0001), but not at 6 weeks postpartum (4.49 log vs. 4.40 log, p=0.79), between single-dose nevirapine/zidovudine+lamivudine and single-dose nevirapine groups, respectively. Nevirapine resistance, measured by population sequencing and sensitive real-time PCR, was significantly less common in those receiving single-dose nevirapine/zidovudine+lamivudine compared to single-dose nevirapine, respectively, at 2 weeks (10% (4/40) vs. 74% (31/42), p<0.0001) and 6 weeks postpartum [10% (11/115) vs. 64% (41/64), p<0.0001; adjusted relative risk=0.18, 95% confidence interval (0.10–0.34)]. Conclusions The significant decrease in nevirapine resistance conferred by one week of zidovudine+lamivudine should help policymakers optimize peripartum HIV prophylaxis recommendations. PMID:20672451

  16. The combination of arsenic, interferon-alpha, and zidovudine restores an "immunocompetent-like" cytokine expression profile in patients with adult T-cell leukemia lymphoma.

    PubMed

    Kchour, Ghada; Rezaee, Rahim; Farid, Reza; Ghantous, Akram; Rafatpanah, Houshang; Tarhini, Mahdi; Kooshyar, Mohamad-Mehdi; El Hajj, Hiba; Berry, Fadwa; Mortada, Mohamad; Nasser, Roudaina; Shirdel, Abbas; Dassouki, Zeina; Ezzedine, Mohamad; Rahimi, Hossein; Ghavamzadeh, Ardeshir; de Thé, Hugues; Hermine, Olivier; Mahmoudi, Mahmoud; Bazarbachi, Ali

    2013-08-20

    HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN. Here we assessed Th1/Th2/T(reg) cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. ATL patients at diagnosis displayed a T(reg)/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4⁺CD25⁺ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4⁺CD25⁺ cells. Finally, IL-10 transcript level negatively correlated with clinical response at Day 30. The observed shift from a T(reg)/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections.

  17. Addition of 7 days of zidovudine plus lamivudine to peripartum single-dose nevirapine effectively reduces nevirapine resistance postpartum in HIV-infected mothers in Malawi.

    PubMed

    Farr, Sherry L; Nelson, Julie A E; Ng'ombe, Thokozani J; Kourtis, Athena P; Chasela, Charles; Johnson, Jeffrey A; Kashuba, Angela D M; Tegha, Gerald L; Wiener, Jeffrey; Eron, Joseph J; Banda, Harriet N; Mpaso, Mwanangwa; Lipscomb, Jonathan; Matiki, Chrissie; Fiscus, Susan A; Jamieson, Denise J; van der Horst, Charles

    2010-08-01

    We assessed whether 7 days of zidovudine + lamivudine postpartum with single-dose nevirapine at labor decreases nevirapine resistance in HIV-infected women in Malawi. HIV-infected pregnant women receiving intrapartum single-dose nevirapine and 7 days of zidovudine + lamivudine (n = 132) and women receiving intrapartum single-dose nevirapine alone (n = 66) were followed from an antenatal visit through 6 weeks postpartum. Plasma specimens at 2 and 6 weeks postpartum were tested for genotypic resistance to nevirapine by population sequencing and sensitive real-time polymerase chain reaction. Poisson regression was used to determine predictors of postpartum nevirapine resistance. Median HIV RNA was similar at entry (4.27 log vs. 4.35 log, P = 0.87), differed at 2 weeks postpartum (2.67 log vs. 3.58 log, P < 0.0001) but not at 6 weeks postpartum (4.49 log vs. 4.40 log, P = 0.79), between single-dose nevirapine/zidovudine + lamivudine and single-dose nevirapine groups, respectively. Nevirapine resistance, measured by population sequencing and sensitive real-time polymerase chain reaction, was significantly less common in those receiving single-dose nevirapine/zidovudine + lamivudine compared with single-dose nevirapine, respectively, at 2 weeks [10% (4 of 40) vs. 74% (31 of 42), P < 0.0001] and 6 weeks postpartum [10% (11 of 115) vs. 64% (41 of 64), P < 0.0001; adjusted relative risk = 0.18, 95% confidence interval (0.10 to 0.34)]. The significant decrease in nevirapine resistance conferred by 1 week of zidovudine + lamivudine should help policymakers optimize peripartum HIV prophylaxis recommendations.

  18. An Intact Retroviral Gene Conserved in Spiny-Rayed Fishes for over 100 My.

    PubMed

    Henzy, Jamie E; Gifford, Robert J; Kenaley, Christopher P; Johnson, Welkin E

    2016-12-30

    We have identified a retroviral envelope gene with a complete, intact open reading frame (ORF) in 20 species of spiny-rayed fishes (Acanthomorpha). The taxonomic distribution of the gene, "percomORF", indicates insertion into the ancestral lineage >110 Ma, making it the oldest known conserved gene of viral origin in a vertebrate genome. Underscoring its ancient provenence, percomORF exists as an isolated ORF within the intron of a widely conserved host gene, with no discernible proviral sequence nearby. Despite its remarkable age, percomORF retains canonical features of a retroviral glycoprotein, and tests for selection strongly suggest cooption for a host function. Retroviral envelope genes have been coopted for a role in placentogenesis by numerous lineages of mammals, including eutherians and marsupials, representing a variety of placental structures. Therefore percomORF's presence within the group Percomorpha-unique among spiny-finned fishes in having evolved placentation and live birth-is especially intriguing.

  19. [Construction and characterization of a novel recombinant retroviral vector expressing mouse T-bet].

    PubMed

    Zhang, Xuejie; Zhang, Jianhua; Zhang, Wei; Guo, Jie; Zhou, Xuyu

    2014-10-01

    In order to study T-bet function in mouse cells, a novel retroviral vector expressing mouse T-bet and reporter gene Thy1.1 was constructed. Retrovirus particles were then produced by transfection of the recombinant retroviral plasmid into a packaging cell line Platinum-E. The recombinant retrovirus played considerable infection ability. T-bet expression was then identified by FACS after infection of CD4+ primary T cells from T-bet knockout mouse with recombinant retrovirus. To determine if exogenous expressing T-bet has normal function, we checked the expression level of T-bet target gene, Ifng. IFN-y expression was upregulated in the T-bet knockout T cells infected with recombinant retrovirus. In conclusion, we successfully constructed an effective mouse T-bet recombinant retroviral vector.

  20. An XMRV Derived Retroviral Vector as a Tool for Gene Transfer

    PubMed Central

    2011-01-01

    Background Retroviral vectors are widely used tools for gene delivery and gene therapy. They are useful for gene expression studies and genetic manipulation in vitro and in vivo. Many retroviral vectors are derived from the mouse gammaretrovirus, murine leukemia virus (MLV). These vectors have been widely used in gene therapy clinical trials. XMRV, initially found in prostate cancer tissue, was the first human gammaretrovirus described. Findings We developed a new retroviral vector based on XMRV called pXC. It was developed for gene transfer to human cells and is produced by transient cotransfection of LNCaP cells with pXC and XMRV-packaging plasmids. Conclusions We demonstrated that pXC mediates expression of inserted transgenes in cell lines. This new vector will be a useful tool for gene transfer in human and non-human cell lines, including gene therapy studies. PMID:21651801

  1. Optimization of a retroviral vector for transduction of human CD34 positive cells.

    PubMed

    Szyda, Anna; Paprocka, Maria; Krawczenko, Agnieszka; Lenart, Katarzyna; Heimrath, Jerzy; Grabarczyk, Piotr; Mackiewicz, Andrzej; Duś, Danuta

    2006-01-01

    Human stem and progenitor cells have recently become objects of intensive studies as an important target for gene therapy and regenerative medicine. Retroviral vectors are among the most effective tools for genetic modification of these cells. However, their transduction efficiency strongly depends on the choice of the ex vivo transduction system. The aim of this study was to elaborate a system for retroviral vector transduction of human CD34 positive cells isolated from cord blood. The retroviral vector pMINV EGFP was chosen for transduction of two human erythroblastoid cell lines: KG-1a (CD34 positive) and K562 (CD34 negative). For vector construction, three promoters and two retroviral vector packaging cell lines were used. To optimize the physicochemical conditions of the transduction process, different temperatures of supernatant harvesting, the influence of centrifugation and the presence of transduction enhancing agents were tested. The conditions elaborated with KG-1a cells were further applied for transduction of CD34 positive cells isolated from cord blood. The optimal efficiency of transduction of CD34 positive cells with pMINV EGFP retroviral vector (26% of EGFP positive cells), was obtained using infective vector with LTR retroviral promoter, produced by TE FLY GA MINV EGFP packaging cell line. The transduction was performed in the presence of serum, at 37 degrees C, with co-centrifugation of cells with viral supernatants and the use of transduction enhancing agents. This study confirmed that for gene transfer into CD34 positive cells, the detailed optimization of each element of the transduction process is of great importance.

  2. Purification of retroviral vectors for clinical application: biological implications and technological challenges.

    PubMed

    Rodrigues, Teresa; Carrondo, Manuel J T; Alves, Paula M; Cruz, Pedro E

    2007-01-10

    For centuries mankind led a difficult battle against viruses, the smallest infectious agents at the surface of the earth. Nowadays it is possible to use viruses for our benefit, both at a prophylactic level in the production of vaccines and at a therapeutic level in the promising field of gene therapy. Retroviruses were discovered at the end of the 19th century and constitute one of the most effective entities for gene transfer and insertion into the genome of mammalian cells. This attractive feature has intensified research in retroviral vectors development and production over the past years, mainly due to the expectations raised by the concept of gene therapy. The demand for high quality retroviral vectors that meet standard requisites from the regulatory agencies (FDA and EMEA) is therefore increasing, as the technology has moved into clinical trials. The development of safer producer cell lines that can be used in large-scale production will result in the production of large quantities of retroviral stocks. Cost-efficient and scalable purification processes are essential for production of injectable-grade preparations to achieve final implementation of these vectors as therapeutics. Several preparative purification steps already established for proteins can certainly be applied to retroviral vectors, in particular membrane filtration and chromatographic methods. Nevertheless, the special properties of these complex products require technological improvement of the existing purification steps and/or development of particular purification steps to increase productivity and throughput, while maintaining biological activity of the final product. This review focuses on downstream process development in relation to the retroviral vectors characteristics and quality assessment of retroviral stocks for intended use in gene therapy.

  3. Evidence for integration of retroviral vectors in a novel human repeat sequence

    SciTech Connect

    Kurdi-Haidar, B.; Friedmann, T.

    1994-09-01

    Retroviruses have become attractive vehicles for the introduction of foreign genes into mammalian cells not only for gene therapy but also to serve as anchor points for long-range mapping purposes. The information relating to retroviral integration in mammalian cells is derived mostly from studies of rodent genomes. The absence of information regarding integration sites of murine-based retroviral vectors in human cells has prompted us to investigate the characteristics of integration sites in the human genome. We have constructed a Moloney murine leukemia virus-based retroviral vector that carries the pUC8 origin of replication and the chloramphenicol resistance gene to allow the rescue of the flanking genomic sequences in plasmid form. We have infected human primary fibroblasts and myoblasts with this retroviral vector and isolated independently transduced clones. Genomic DNA was obtained from independent clones and the genomic fragment carrying the provirus-host sequence boundary was isolated after digestion of the genomic DNA, circularization, and transformation by electroporation of E. coli C cells to chloramphenicol resistance. Restriction map and nucleotide sequence analysis of the rescued plasmids showed that a number of the clones shared the same integration site within the human genome. We have used the nucleotide sequence information about the human DNA adjacent to the 3{prime}LTR to design a PCR-based assay diagnostic for this common integration site. Analysis revealed the presence of the same integration site in four out of twelve human primary fibroblast clones infected with this specific retroviral vector, and in one out of twelve human primary myoblast clones infected with a second retroviral vector. Further analysis revealed the common integration site to be a previously unreported primate repeat present in monkey and human genomes and absent from rodent, bovine and avian genomes.

  4. Baseline severe anaemia should not preclude use of zidovudine in antiretroviral-eligible patients in resource-limited settings

    PubMed Central

    2010-01-01

    Background Stavudine is no longer recommended as part of first-line therapy for patients initiating antiretroviral therapy (ART) in Uganda. Most patients are currently initiated on zidovudine-containing regimens, which can induce anaemia. We investigated the risk factors for early severe anaemia in the first six months of ART initiation. Methods We defined baseline (ART initiation) anaemia as haemoglobin (Hb) ≤9.5 g/dL, baseline severe anaemia as Hb ≤8 g/dL, and early severe anaemia as Hb ≤8 g/dL within six months of ART initiation. Risk factors for the development of early severe anaemia were analyzed using a multivariable logistic regression model. Results In total, 5494 patients initiated ART, 821 (15%) had baseline anaemia, and 296 (5%) had baseline severe anaemia. Early severe anaemia occurred in 109 (4%) of 3105 patients who had at least one Hb measurement in the first six months on ART. Patients with baseline anaemia had a larger increase in Hb (median g/dL [IQR]) within the first six months compared with non-anaemic patients (2.9 [1.7, 4.6] vs. 0.7 [-0.2, 1.7], p < 0.0001). Having a new tuberculosis episode OR 3.69 (95% CI 1.64 - 8.32), MCV <80fL OR 1.60 (95% CI 1.01- 2.52) and baseline severe anaemia OR 5.27 (95% CI 3.00 - 9.26) were associated with early severe anaemia. Initiation on a zidovudine-based regimen was not associated with an increased risk of early severe anaemia. Conclusions Among patients in an urban HIV clinic in Uganda, severe anaemia is modestly prevalent at ART initiation and improves with ART in the majority of patients. These data suggest that baseline severe anaemia should not be used as a criterion for avoiding the use of zidovudine in patients initiating ART in resource-limited settings. PMID:21047391

  5. Comparative Application of PLS and PCR Methods to Simultaneous Quantitative Estimation and Simultaneous Dissolution Test of Zidovudine - Lamivudine Tablets.

    PubMed

    Üstündağ, Özgür; Dinç, Erdal; Özdemir, Nurten; Tilkan, M Günseli

    2015-01-01

    In the development strategies of new drug products and generic drug products, the simultaneous in-vitro dissolution behavior of oral dosage formulations is the most important indication for the quantitative estimation of efficiency and biopharmaceutical characteristics of drug substances. This is to force the related field's scientists to improve very powerful analytical methods to get more reliable, precise and accurate results in the quantitative analysis and dissolution testing of drug formulations. In this context, two new chemometric tools, partial least squares (PLS) and principal component regression (PCR) were improved for the simultaneous quantitative estimation and dissolution testing of zidovudine (ZID) and lamivudine (LAM) in a tablet dosage form. The results obtained in this study strongly encourage us to use them for the quality control, the routine analysis and the dissolution test of the marketing tablets containing ZID and LAM drugs.

  6. Pure red cell aplasia induced by lamivudine without the influence of zidovudine in a patient infected with human immunodeficiency virus.

    PubMed

    Nakamura, Kiwamu; Tateyama, Masao; Tasato, Daisuke; Haranaga, Shusaku; Tamayose, Maki; Yara, Satomi; Higa, Futoshi; Fujita, Jiro

    2014-01-01

    We herein report the case of a patient with human immunodeficiency virus infection and acquired immune deficiency syndrome who was diagnosed with drug-induced pure red cell aplasia consequent to lamivudine treatment. The patient was admitted to our hospital for treatment of increasing shortness of breath following physical effort. Upon admission, routine blood tests revealed a hemoglobin level of 7.6 g/dL and a hematocrit proportion of 21.2%, with normal leukocyte and platelet counts. After stopping the lamivudine treatment, the patient's hemoglobin concentration and hematocrit level returned to normal. A bone marrow examination showed an exclusive reduction in erythrocyte formation. This case indicates that lamivudine can induce severe anemia without the influence of zidovudine.

  7. [Prevalence of transmission of zidovudine-resistant viruses in Switzerland. l'Etude suisse de cohorte VIH].

    PubMed

    Yerly, S; Rakik, A; Kinloch-de-Loes, S; Erb, P; Vernazza, P; Hirschel, B; Perrin, L

    1996-10-26

    Zidovudine (ZDV) was the most widely used anti-HIV drug between 1987 and 1995, and, as already reported, transmission of ZDV-resistant viruses occurs. Several mutations of the reverse transcriptase gene have been identified; one of them affects the 215 codon and is associated with a high degree of resistance. We have determined, using selective PCR, the prevalence of transmission of 215 mutant isolates in 134 patients with primary HIV infection (PHI) and have identified 8 patients with 215 mutant virus between 1989 and 1995 in Switzerland. Mutant resistant viruses have been isolated from patients treated with most antiviral drugs. A systematic search for mutant viruses may provide useful information for the adaptation of treatment strategies.

  8. Pharmacokinetic Modeling of Lamivudine and Zidovudine Triphosphates Predicts Differential Pharmacokinetics in Seminal Mononuclear Cells and Peripheral Blood Mononuclear Cells.

    PubMed

    Dumond, Julie B; Yang, Kuo H; Kendrick, Racheal; Reddy, Y Sunila; Kashuba, Angela D M; Troiani, Luigi; Bridges, Arlene S; Fiscus, Susan A; Forrest, Alan; Cohen, Myron S

    2015-10-01

    The male genital tract is a potential site of viral persistence. Therefore, adequate concentrations of antiretrovirals are required to eliminate HIV replication in the genital tract. Despite higher zidovudine (ZDV) and lamivudine (3TC) concentrations in seminal plasma (SP) than in blood plasma (BP) (SP/BP drug concentration ratios of 2.3 and 6.7, respectively), we have previously reported lower relative intracellular concentrations of their active metabolites, zidovudine triphosphate (ZDV-TP) and lamivudine triphosphate (3TC-TP), in seminal mononuclear cells (SMCs) than in peripheral blood mononuclear cells (PBMCs) (SMC/PBMC drug concentration ratios of 0.36 and 1.0, respectively). Here, we use population pharmacokinetic (PK) modeling-based methods to simultaneously describe parent and intracellular metabolite PK in blood, semen, and PBMCs and SMCs. From this model, the time to steady state in each matrix was estimated, and the results indicate that the PK of 3TC-TP and ZDV-TP in PBMCs are different from the PK of the two in SMCs and different for the two triphosphates. We found that steady-state conditions in PBMCs were achieved within 2 days for ZDV-TP and 3 days for 3TC-TP. However, steady-state conditions in SMCs were achieved within 2 days for ZDV-TP and 2 weeks for 3TC-TP. Despite this, or perhaps because of it, ZDV-TP in SMCs does not achieve the surrogate 50% inhibitory concentration (IC50) (as established for PBMCs, assuming SMC IC50 = PBMC IC50) at the standard 300-mg twice-daily dosing. Mechanistic studies are needed to understand these differences and to explore intracellular metabolite behavior in SMCs for other nucleoside analogues used in HIV prevention, treatment, and cure.

  9. Validation of a sensitive LC/MS/MS method for the determination of zidovudine and lamivudine in human plasma

    PubMed Central

    Rower, Joseph E.; Klein, Brandon; Bushman, Lane R.; Anderson, Peter L.

    2011-01-01

    A sensitive LC/MS/MS assay for determining zidovudine (ZDV) and lamivudine (3TC) in human plasma was validated to support antiretroviral pharmacology research programs. After addition of stable labeled isotopic zidovudine (ZDV-IS) and lamivudine (3TC-IS) as internal standard, a solid phase extraction was performed with an Oasis HLB 1cc cartridge, with recoveries of 92.3% for ZDV and 93.9% for 3TC. A Phenomonex Synergi Hydro-RP (2.0 × 150 mm) reversed phase analytical column was utilized for chromatographic separation. Mobile phase consisted of an aqueous solution of 15% acetonitrile and 0.1% acetic acid. Detection was accomplished by ESI/MS/MS in the positive ion mode, monitoring 268/127 and 271/130, and 230/112 and 233/115 transitions, for ZDV and ZDV-IS and 3TC and 3TC-IS, respectively. The method was linear from 1 to 3000 ng/mL with a minimum quantifiable limit of 1 ng/mL when 100 μL of plasma were analyzed. Validations results demonstrated high accuracy (≤ 8.3% deviation) and high precision (≤ 10% CV) for the quality control samples. The method was also shown to be specific and reproducible. The value of the high sensitivity was demonstrated by quantitation of approximately 100 existing samples that had ZDV below the limit of quantitation using a previously validated, less sensitive HPLC-UV method utilized in the laboratory. PMID:21465499

  10. Pharmacokinetic Modeling of Lamivudine and Zidovudine Triphosphates Predicts Differential Pharmacokinetics in Seminal Mononuclear Cells and Peripheral Blood Mononuclear Cells

    PubMed Central

    Yang, Kuo H.; Kendrick, Racheal; Reddy, Y. Sunila; Kashuba, Angela D. M.; Troiani, Luigi; Bridges, Arlene S.; Fiscus, Susan A.; Forrest, Alan; Cohen, Myron S.

    2015-01-01

    The male genital tract is a potential site of viral persistence. Therefore, adequate concentrations of antiretrovirals are required to eliminate HIV replication in the genital tract. Despite higher zidovudine (ZDV) and lamivudine (3TC) concentrations in seminal plasma (SP) than in blood plasma (BP) (SP/BP drug concentration ratios of 2.3 and 6.7, respectively), we have previously reported lower relative intracellular concentrations of their active metabolites, zidovudine triphosphate (ZDV-TP) and lamivudine triphosphate (3TC-TP), in seminal mononuclear cells (SMCs) than in peripheral blood mononuclear cells (PBMCs) (SMC/PBMC drug concentration ratios of 0.36 and 1.0, respectively). Here, we use population pharmacokinetic (PK) modeling-based methods to simultaneously describe parent and intracellular metabolite PK in blood, semen, and PBMCs and SMCs. From this model, the time to steady state in each matrix was estimated, and the results indicate that the PK of 3TC-TP and ZDV-TP in PBMCs are different from the PK of the two in SMCs and different for the two triphosphates. We found that steady-state conditions in PBMCs were achieved within 2 days for ZDV-TP and 3 days for 3TC-TP. However, steady-state conditions in SMCs were achieved within 2 days for ZDV-TP and 2 weeks for 3TC-TP. Despite this, or perhaps because of it, ZDV-TP in SMCs does not achieve the surrogate 50% inhibitory concentration (IC50) (as established for PBMCs, assuming SMC IC50 = PBMC IC50) at the standard 300-mg twice-daily dosing. Mechanistic studies are needed to understand these differences and to explore intracellular metabolite behavior in SMCs for other nucleoside analogues used in HIV prevention, treatment, and cure. PMID:26239974

  11. Superior Effectiveness of Zidovudine Compared With Tenofovir When Combined With Nevirapine-based Antiretroviral Therapy in a Large Nigerian Cohort

    PubMed Central

    Scarsi, Kimberly K.; Eisen, Geoffrey; Darin, Kristin M.; Meloni, Seema T.; Rawizza, Holly E.; Tchetgen Tchetgen, Eric J.; Agbaji, Oche O.; Onwujekwe, Daniel I.; Gashau, Wadzani; Nkado, Reuben; Okonkwo, Prosper; Murphy, Robert L.; Kanki, Phyllis J.

    2016-01-01

    Background. Despite sparse efficacy data, tenofovir–emtricitabine or tenofovir–lamivudine plus nevirapine is used in many resource-constrained settings. Methods. This retrospective cohort study included patients initiating nevirapine-based antiretroviral therapy (ART) with either tenofovir–emtricitabine or lamivudine (tenofovir group) or zidovudine–lamivudine (zidovudine group). Clinical, virologic, and immunologic evaluations were performed at baseline and every 6 months. Virologic failure was defined as 2 consecutive human immunodeficiency virus (HIV)-RNA values >1000 copies/mL. Patients were included from ART initiation until time of failure, regimen switch, discontinuation, or last HIV-RNA measurement. Cox proportional hazards regression was used to model factors influencing time to failure. Bias due to dependent censoring was investigated via inverse probability weighted pooled logistic regression. Results. A total of 5547 patients were evaluated; 1484 (26.8%) were in the tenofovir group and 4063 (73.2%) were in the zidovudine group. In the adjusted model, tenofovir regimen (hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.21–1.79) and higher baseline log10 HIV-RNA (HR, 1.15; 95% CI, 1.03–1.28) were associated with virologic failure. Higher baseline log10 CD4+ cell count (HR, 0.50; 95% CI, .40–.63) and increasing age (HR, 0.98; 95% CI, .97–.99) decreased the risk of virologic failure. Inverse probability weighting results were consistent with the primary analysis. Conclusions. Compared with zidovudine–lamivudine, the use of tenofovir–lamivudine or emtricitabine in combination with nevirapine was a strong predictor of virologic failure in our cohort, which was not explained by other risk factors or criteria for regimen selection. PMID:26561532

  12. Investigating the dissolution profiles of amoxicillin, metronidazole, and zidovudine formulations used in Trinidad and Tobago, West Indies.

    PubMed

    Stuart, Arlene Villarroel; Zuo, Jieyu; Löbenberg, Raimar

    2014-10-01

    Trinidad and Tobago is a twin-island Republic in the Caribbean and like many developing countries, it has included generic drugs on the national drug formulary to decrease the financial burden of pharmaceutical medications. However, to ensure that medications received by patients are beneficial, generic drugs need to be interchangeable with the innovator which has demonstrated safety, efficacy, and quality. The objective of the study was to compare the dissolution profiles and weight variations for different formulations of amoxicillin, metronidazole, and zidovudine that are on the national drug formulary and marketed in Trinidad and Tobago. All the products investigated are categorized as class 1 drugs according to the Biopharmaceutics Classification System (BCS) and the dissolution profiles were assessed according to the World Health Organization (WHO) criteria for interchangeability between products. The similarity factor, f 2, was used to determine sameness between the products. No generic formulation was found to be similar to Amoxil® 500-mg capsules. The two generic products for metronidazole 200-mg tablets demonstrated more than 85% drug release within 15 min in all three of the buffers; however, their 400-mg counterparts did not fulfill this requirement. The zidovudine 300-mg tablet complied with the requirements in buffer pH 4.5 and simulated gastric fluid (SGF) but not for simulated intestinal fluid (SIF). Some Class 1 pharmaceutical formulations may possess the same active ingredient and amount of drug but may show significant differences to in vitro equivalence requirements. Nevertheless, the dissolution process is suitable to detect these variations.

  13. Disclosing the parameters leading to high productivity of retroviral producer cells lines: evaluating random vs. targeted integration.

    PubMed

    Bandeira, Vanessa Sofia; Tomás, Hélio A; Alici, Evren; Carrondo, Manuel J C T; Coroadinha, Ana Sofia

    2017-03-16

    Gammaretrovirus and lentivirus are the preferred viral vectors to genetically modify T- and NK- cells to be used in immune-cell therapies. The transduction efficiency of hematopoietic and T cells is more efficient using Gibbon ape leukemia virus (GaLV) pseudotyping. In this context gammaretroviral vector producer cells offer competitive higher titers than transient lentiviral vectors productions. The main aim of this work was to identify the key parameters governing GalV pseudotyped gammaretroviral vector productivity in stable producer cells using a retroviral vector expression cassette enabling positive (facilitating cell enrichment) and negative cell selection (allowing cell elimination). The retroviral vector contains a thymidine kinase suicide gene fused with an Ouabain-resistant Na+K+-ATPase gene, a potential safer and faster marker. The establishment of retroviral vector producer cells is traditionally performed by randomly integrating the retroviral vector expression cassette codifying the transgene. More recently recombinase mediated cassette exchange methodologies have been introduced to achieve targeted integration. Herein we compared random and targeted integration of the retroviral vector transgene construct. Two retroviral producer cell lines, 293 OuaS and 293 FlexOuaS, were generated using random and targeted integration, respectively, producing high titers (in the order of 107 IP.mL-1). Results showed that the retroviral vector transgene cassette is the key retroviral vector component determining the viral titers notwithstanding, single copy integration is sufficient to provide high titers. The expression levels of the three retroviral constructs (gag-pol, GaLV env and retroviral vector transgene) were analyzed. Although gag-pol and GaLV env gene expression levels should surpass a minimal threshold, we found that relatively modest expression levels of these two expression cassettes are required. Their levels of expression should not be maximized. We

  14. Efficacy and safety of one-month postpartum zidovudine and didanosine to prevent HIV-resistance mutations following intrapartum single-dose nevirapine

    PubMed Central

    Lallemant, Marc; Ngo-Giang-Huong, Nicole; Jourdain, Gonzague; Traisaithit, Patrinee; Cressey, Tim R.; Collins, Intira J.; Jarupanich, Tapnarong; Sukhumanant, Thammanoon; Achalapong, Jullapong; Sabsanong, Prapan; Chotivanich, Nantasak; Winiyakul, Narong; Ariyadej, Surabon; Kanjanasing, Annop; Ratanakosol, Janyaporn; Hemvuttiphan, Jittapol; Kengsakul, Karun; Wannapira, Wiroj; Sittipiyasakul, Veerachai; Pornkitprasarn, Witaya; Liampongsabuddhi, Prateung; McIntosh, Kenneth; Van Dyke, Russell B.; Frenkel, Lisa M.; Koetsawang, Suporn; Le Coeur, Sophie

    2009-01-01

    Background Intrapartum single-dose-nevirapine along with third trimester maternal and infant zidovudine are essential components of programs to prevent mother-to-child HIV transmission in resource-limited settings. The persistence of nevirapine in the plasma for three weeks postpartum risks selection of resistance mutations to non-nucleoside reverse transcriptase inhibitors (NNRTI). We hypothesized that a one-month zidovudine-plus-didanosine course initiated at the same time as single-dose nevirapine would prevent the selection of nevirapine resistance mutations. Methods PHPT-4 HIV-infected pregnant women with CD4 counts above 250 cells/mm3 received antepartum zidovudine from the third trimester until delivery, single-dose nevirapine during labor and one-month zidovudine-plus-didanosine postpartum. These women were matched on baseline viral load (VL), CD4 count and duration of antepartum zidovudine to women who received single-dose nevirapine in the PHPT-2 trial (controls). Consensus sequencing and the more sensitive oligonucleotide ligation assay (OLA) were performed on samples drawn at 7–10, 37–45 and 120 days postpartum (if VL>500 copies/mL) to detect K103N/Y181C/G190A mutations. Results The 222 PHPT-4 subjects did not differ from their matched controls in baseline characteristics except for age. Combined groups median CD4 count was 421 cells/mm3 [IQR: 322–549], VL 3.45 log10 copies/mL [2.79–4.00] and ZDV prophylaxis 10.4 weeks [9.1–11.4]. Using consensus sequencing, major NNRTI resistance mutations were detected postpartum in 0% of PHPT-4 subjects versus 10.4% of PHPT-2 controls. OLA detected resistance in 1.8% of PHPT-4 subjects versus 18.9% controls. Major NNRTI resistance mutations were detected by either method in 1.8% of PHPT-4 subjects versus 20.7% in controls (p<10−10). Conclusions One-month postpartum zidovudine-plus-didanosine prevented the selection of vast majority NNRTI resistance mutations. PMID:20158398

  15. Biochemical characterization of a multi-drug resistant HIV-1 subtype AG reverse transcriptase: antagonism of AZT discrimination and excision pathways and sensitivity to RNase H inhibitors

    PubMed Central

    Schneider, Anna; Corona, Angela; Spöring, Imke; Jordan, Mareike; Buchholz, Bernd; Maccioni, Elias; Di Santo, Roberto; Bodem, Jochen; Tramontano, Enzo; Wöhrl, Birgitta M.

    2016-01-01

    We analyzed a multi-drug resistant (MR) HIV-1 reverse transcriptase (RT), subcloned from a patient-derived subtype CRF02_AG, harboring 45 amino acid exchanges, amongst them four thymidine analog mutations (TAMs) relevant for high-level AZT (azidothymidine) resistance by AZTMP excision (M41L, D67N, T215Y, K219E) as well as four substitutions of the AZTTP discrimination pathway (A62V, V75I, F116Y and Q151M). In addition, K65R, known to antagonize AZTMP excision in HIV-1 subtype B was present. Although MR-RT harbored the most significant amino acid exchanges T215Y and Q151M of each pathway, it exclusively used AZTTP discrimination, indicating that the two mechanisms are mutually exclusive and that the Q151M pathway is obviously preferred since it confers resistance to most nucleoside inhibitors. A derivative was created, additionally harboring the TAM K70R and the reversions M151Q as well as R65K since K65R antagonizes excision. MR-R65K-K70R-M151Q was competent of AZTMP excision, whereas other combinations thereof with only one or two exchanges still promoted discrimination. To tackle the multi-drug resistance problem, we tested if the MR-RTs could still be inhibited by RNase H inhibitors. All MR-RTs exhibited similar sensitivity toward RNase H inhibitors belonging to different inhibitor classes, indicating the importance of developing RNase H inhibitors further as anti-HIV drugs. PMID:26850643

  16. Identification of candidate cancer-causing genes in mouse brain tumors by retroviral tagging

    PubMed Central

    Johansson, Fredrik K.; Brodd, Josefin; Eklöf, Charlotta; Ferletta, Maria; Hesselager, Göran; Tiger, Carl-Fredrik; Uhrbom, Lene; Westermark, Bengt

    2004-01-01

    Murine retroviruses may cause malignant tumors in mice by insertional mutagenesis of host genes. The use of retroviral tagging as a means of identifying cancer-causing genes has, however, almost entirely been restricted to hematopoietic tumors. The aim of this study was to develop a system allowing for the retroviral tagging of candidate genes in malignant brain tumors. Mouse gliomas were induced by a recombinant Moloney murine leukemia virus encoding platelet-derived growth factor (PDGF) B-chain. The underlying idea was that tumors evolve through a combination of PDGF-mediated autocrine growth stimulation and insertional mutagenesis of genes that cooperate with PDGF in gliomagenesis. Common insertion sites (loci that were tagged in more than one tumor) were identified by cloning and sequencing retroviral flanking segments, followed by blast searches of mouse genome databases. A number of candidate brain tumor loci (Btls) were identified. Several of these Btls correspond to known tumor-causing genes; these findings strongly support the underlying idea of our experimental approach. Other Btls harbor genes with a hitherto unproven role in transformation or oncogenesis. Our findings indicate that retroviral tagging with a growth factor-encoding virus may be a powerful means of identifying candidate tumor-causing genes in nonhematopoietic tumors. PMID:15273287

  17. Characterization of retroviral infectivity and superinfection resistance during retrovirus-mediated transduction of mammalian cells.

    PubMed

    Liao, J; Wei, Q; Fan, J; Zou, Y; Song, D; Liu, J; Liu, F; Ma, C; Hu, X; Li, L; Yu, Y; Qu, X; Chen, L; Yu, X; Zhang, Z; Zhao, C; Zeng, Z; Zhang, R; Yan, S; Wu, T; Wu, X; Shu, Y; Lei, J; Li, Y; Zhang, W; Wang, J; Reid, R R; Lee, M J; Huang, W; Wolf, J M; He, T-C; Wang, J

    2017-04-07

    Retroviral vectors including lentiviral vectors are commonly-used tools to stably express transgenes or RNA molecules in mammalian cells. Their utilities are roughly divided into two categories, stable overexpression of transgenes and RNA molecules, which requires maximal transduction efficiency, or functional selection with retrovirus-based libraries, which takes advantage of retroviral superinfection resistance. However, the dynamic features of retrovirus-mediated transduction are not well-characterized. Here, we engineered two MSCV-based retroviral vectors expressing dual fluorescence proteins and antibiotic markers and analyzed virion production efficiency and virion stability, dynamic infectivity and superinfection resistance in different cell types, and strategies to improve transduction efficiency. We found that the highest virion production occurred between 60 and 72 h after transfection. The stability of the harvested virion supernatant decreased by >60% after three days in storage. We found that retrovirus infectivity varied drastically in the tested human cancer lines, while low transduction efficiency was partially overcome with increased virus titer, prolonged infection duration, and/or repeated infections. Furthermore, we demonstrated that retrovirus receptors PIT1 and PIT2 were lowly expressed in the analyzed cells, and that PIT1 and/or PIT2 overexpression significantly improved transduction efficiency in certain cell lines. Thus, our findings provide resourceful information for the optimal conditions of retroviral-mediated gene delivery.Gene Therapy accepted article preview online, 07 April 2017. doi:10.1038/gt.2017.24.

  18. Statistical analysis of sparse infection data and its implications for retroviral treatment trials in primates.

    PubMed Central

    Spouge, J L

    1992-01-01

    Reports on retroviral primate trials rarely publish any statistical analysis. Present statistical methodology lacks appropriate tests for these trials and effectively discourages quantitative assessment. This paper describes the theory behind VACMAN, a user-friendly computer program that calculates statistics for in vitro and in vivo infectivity data. VACMAN's analysis applies to many retroviral trials using i.v. challenges and is valid whenever the viral dose-response curve has a particular shape. Statistics from actual i.v. retroviral trials illustrate some unappreciated principles of effective animal use: dilutions other than 1:10 can improve titration accuracy; infecting titration animals at the lowest doses possible can lower challenge doses; and finally, challenging test animals in small trials with more virus than controls safeguards against false successes, "reuses" animals, and strengthens experimental conclusions. The theory presented also explains the important concept of viral saturation, a phenomenon that may cause in vitro and in vivo titrations to agree for some retroviral strains and disagree for others. PMID:1323844

  19. XPB mediated retroviral cDNA degradation coincides with entry to the nucleus

    SciTech Connect

    Yoder, Kristine E.; Roddick, William; Hoellerbauer, Pia; Fishel, Richard

    2011-02-20

    Retroviruses must integrate their cDNA to a host chromosome, but a significant fraction of retroviral cDNA is degraded before integration. XPB and XPD are part of the TFIIH complex which mediates basal transcription and DNA nucleotide excision repair. Retroviral infection increases when XPB or XPD are mutant. Here we show that inhibition of mRNA or protein synthesis does not affect HIV cDNA accumulation suggesting that TFIIH transcription activity is not required for degradation. Other host factors implicated in the stability of cDNA are not components of the XPB and XPD degradation pathway. Although an increase of retroviral cDNA in XPB or XPD mutant cells correlates with an increase of integrated provirus, the integration efficiency of pre-integration complexes is unaffected. Finally, HIV and MMLV cDNA degradation appears to coincide with nuclear import. These results suggest that TFIIH mediated cDNA degradation is a nuclear host defense against retroviral infection.

  20. Inhibition of Marek's disease virus replication by retroviral vector-based RNA interference

    USDA-ARS?s Scientific Manuscript database

    RNA interference (RNAi) is a promising antiviral methodology. We recently demonstrated that retroviral vectors expressing short hairpin RNAs (shRNA-mirs) in the context of a modified endogenous micro-RNA (miRNA) can be effective in reducing replication of other retroviruses in chicken cells. In thi...

  1. Retroviral vectors elevate coexpressed protein levels in trans through cap-dependent translation.

    PubMed

    Gou, Yongqiang; Byun, Hyewon; Zook, Adam E; Singh, Gurvani B; Nash, Andrea K; Lozano, Mary M; Dudley, Jaquelin P

    2015-03-17

    Retroviruses cause immunodeficiency and cancer but also are used as vectors for the expression of heterologous genes. Nevertheless, optimal translation of introduced genes often is not achieved. Here we show that transfection into mammalian cells of lentiviral or gammaretroviral vectors, including those with specific shRNAs, increased expression of a cotransfected gene relative to standard plasmid vectors. Levels of most endogenous cellular proteins were unchanged. Transfer of lentiviral vector sequences into a standard plasmid conferred the ability to give increased expression of cotransfected genes (superinduction). Superinduction by the retroviral vector was not dependent on the cell type or species, the type of reporter gene, or the method of transfection. No differences were detected in the IFN, unfolded protein, or stress responses in the presence of retroviral vectors. RT-PCRs revealed that RNA levels of cotransfected genes were unchanged during superinduction, yet Western blotting, pulse labeling, and the use of bicistronic vectors showed increased cap-dependent translation of cointroduced genes. Expression of the mammalian target of rapamycin (mTOR) kinase target 4E-BP1, but not the mTOR inhibitor Torin 1, preferentially inhibited superinduction relative to basal protein expression. Furthermore, transcription of lentiviral vector sequences from a doxycycline-inducible promoter eliminated superinduction, consistent with a DNA-triggered event. Thus, retroviral DNA increased translation of cointroduced genes in trans by an mTOR-independent signaling mechanism. Our experiments have broad applications for the design of retroviral vectors for transfections, DNA vaccines, and gene therapy.

  2. Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions.

    PubMed

    Romano, Oriana; Cifola, Ingrid; Poletti, Valentina; Severgnini, Marco; Peano, Clelia; De Bellis, Gianluca; Mavilio, Fulvio; Miccio, Annarita

    2017-05-28

    Moloney murine leukemia (MLV) virus-based retroviral vectors integrate predominantly in acetylated enhancers and promoters. For this reason, mLV integration sites can be used as functional markers of active regulatory elements. Here, we present a retroviral scanning tool, which allows the genome-wide identification of cell-specific enhancers and promoters. Briefly, the target cell population is transduced with an mLV-derived vector and genomic DNA is digested with a frequently cutting restriction enzyme. After ligation of genomic fragments with a compatible DNA linker, linker-mediated polymerase chain reaction (LM-PCR) allows the amplification of the virus-host genome junctions. Massive sequencing of the amplicons is used to define the mLV integration profile genome-wide. Finally, clusters of recurrent integrations are defined to identify cell-specific regulatory regions, responsible for the activation of cell-type specific transcriptional programs. The retroviral scanning tool allows the genome-wide identification of cell-specific promoters and enhancers in prospectively isolated target cell populations. Notably, retroviral scanning represents an instrumental technique for the retrospective identification of rare populations (e.g. somatic stem cells) that lack robust markers for prospective isolation.

  3. High-resolution structure of a retroviral protease folded as a monomer

    SciTech Connect

    Gilski, Miroslaw; Kazmierczyk, Maciej; Krzywda, Szymon; Zábranská, Helena; Cooper, Seth; Popović, Zoran; Khatib, Firas; DiMaio, Frank; Thompson, James; Baker, David; Pichová, Iva; Jaskolski, Mariusz

    2011-11-01

    The crystal structure of Mason–Pfizer monkey virus protease folded as a monomer has been solved by molecular replacement using a model generated by players of the online game Foldit. The structure shows at high resolution the details of a retroviral protease folded as a monomer which can guide rational design of protease dimerization inhibitors as retroviral drugs. Mason–Pfizer monkey virus (M-PMV), a D-type retrovirus assembling in the cytoplasm, causes simian acquired immunodeficiency syndrome (SAIDS) in rhesus monkeys. Its pepsin-like aspartic protease (retropepsin) is an integral part of the expressed retroviral polyproteins. As in all retroviral life cycles, release and dimerization of the protease (PR) is strictly required for polyprotein processing and virion maturation. Biophysical and NMR studies have indicated that in the absence of substrates or inhibitors M-PMV PR should fold into a stable monomer, but the crystal structure of this protein could not be solved by molecular replacement despite countless attempts. Ultimately, a solution was obtained in mr-rosetta using a model constructed by players of the online protein-folding game Foldit. The structure indeed shows a monomeric protein, with the N- and C-termini completely disordered. On the other hand, the flap loop, which normally gates access to the active site of homodimeric retropepsins, is clearly traceable in the electron density. The flap has an unusual curled shape and a different orientation from both the open and closed states known from dimeric retropepsins. The overall fold of the protein follows the retropepsin canon, but the C{sup α} deviations are large and the active-site ‘DTG’ loop (here NTG) deviates up to 2.7 Å from the standard conformation. This structure of a monomeric retropepsin determined at high resolution (1.6 Å) provides important extra information for the design of dimerization inhibitors that might be developed as drugs for the treatment of retroviral infections

  4. HIV/AIDS treatment and physicochemical quality control of medicines: evaluation of non-generic lamivudine + zidovudine tablets manufactured in Brazil.

    PubMed

    Beck, Ruy Carlos Ruver; Athayde, Margareth Linde; Cardoso, Simone Gonçalves

    2007-12-01

    In this work it was evaluated the physicochemical quality of lamivudine + zidovudine tablets, whose association belongs to the list of drugs distributed by the Brazil's National Program on Sexually Transmitted Diseases and AIDS. Four non-generic products (lamivudine + zidovudine tablets) were analyzed. They were obtained from different Brazilian manufacturers, besides a reference product. The quality was evaluated by physicochemical tests described in the official codes. A validated reversed-phase high performance liquid chromatography (HPLC) method was used for the assay of the active substances. All samples were in accordance to the requisites in relation to their physicochemical characteristics. Dissolution studies showed similar drug percentual dissolved among all samples. The results reflect the interest of the national pharmaceutical industry to ensure the delivery of safer and cheaper drugs to the Brazilian people, with particular importance in the National Program on Sexually Transmitted Diseases and AIDS.

  5. Nevirapine-Resistant HIV-1 DNA in Breast Milk After Single-Dose Nevirapine With or Without Zidovudine for Prevention of Mother-to-Child Transmission

    PubMed Central

    Gantt, Soren; Payant, Rachel; Carlsson, Jacquelyn; Micek, Mark A.; Blanco, Ana Judith; Beck, Ingrid A.; Matunha, Laurinda; Montoya, Pablo; Matediana, Eduardo; Gloyd, Stephen; Frenkel, Lisa M.

    2012-01-01

    Among 30 human immunodeficiency virus type 1 (HIV-1)–infected women who received single-dose nevirapine (NVP), 17 (57%) had NVP-resistant HIV-1 detected in breast milk. NVP resistance in breast milk persisted for at least 8 months postpartum and was apparently transmitted to at least 1 infant. NVP resistance was detected less often in women who also received zidovudine. PMID:23687579

  6. Investigation of the pharmacokinetics and determination of cholesteryl carbonate zidovudine in rat plasma by non-aqueous reversed-phase high performance liquid chromatography with UV detection.

    PubMed

    Zhang, Lingling; Deng, Yihui; Li, Yi; Wu, Hongbing; Xu, Su

    2007-06-15

    A simple reversed phase high-performance liquid chromatographic method was established for the separation and quantification of a novel prodrug of zidovudine in rat plasma. Zidovudine was one of the original drugs used to treat HIV infection. Appropriate aliquots of rat plasma were spiked with cholesteryl carbonate zidovudine (AZTC) and treated with acetonitrile to precipitate plasma proteins. The supernatant after supercentrifugation was collected and an aliquot of 20 microL was injected directly into an HPLC system consisting of a Diamonsil C18 column and a diode array detector. The mobile phase consisted of methanol (85%, v/v) and diethyl ether (15%, v/v) at a flow rate of 1.0 mL/min. The extraction recoveries of AZTC at the three concentrations examined were all higher than 80%. The HPLC assay was linear over the concentration range 0.5-80 microg/mL. A one-compartment model with apparent first-order elimination was used to describe the plasma concentration-time profile for AZTC after administration via the tail vein. The mean elimination half-life (t1/2) was 292.4 min. This RP-HPLC method will be useful for the evaluation of the pharmacokinetics of AZTC in rats.

  7. Slow progress against HIV.

    PubMed

    Alcorn, K

    1995-01-01

    Treatment for people with HIV attempts to prevent HIV from reproducing, boost the immune system, or cure opportunistic infections. The chemical structure of anti-viral drugs is similar to that of DNA. Since HIV bonds with the drugs rather than DNA, it cannot replicate itself. The most widely used anti-viral drug is zidovudine or AZT (brand name, Retrovir), but it does not help HIV infected persons who are still healthy. A recent trial shows that a combination of anti-viral drugs is more likely to delay opportunistic infections and death than AZT alone. When pregnant women use AZT before and during delivery and when their newborns receive AZT therapy, the likelihood of HIV transmission to the newborn is reduced by about 66%. Follow-up studies are needed, however, since AZT is toxic. Disadvantages of anti-viral drugs include resistance, toxicity, side effects (e.g., nausea and anemia), which are particularly severe at high doses, and accessibility of regular and expensive monitoring tests. Protease inhibitors are in the early stages of development. They deactivate the HIV enzyme which allows HIV to attach to white blood cells. Imuthiol (DTC) aims to increase the number of white blood cells so the body can fight HIV longer, but it appears that it has no benefit and may even facilitate development of opportunistic infections. Interleuken 2 may increase the number of CD4 cells. Alternative approaches to strengthening the immune system are lifestyle changes, improved diet, reduced stress, Chinese medicine and acupuncture, herbal medicines, and relaxation exercises. HIV/AIDS therapies are very expensive and often induce side effects. Many HIV positive people in developed countries are opting out of these treatments, even though they have access to them. Prevention and treatment of opportunistic infection remain the best strategies for most HIV-infected persons.

  8. Maternal anaemia and duration of zidovudine in antiretroviral regimens for preventing mother-to-child transmission: a randomized trial in three African countries

    PubMed Central

    2013-01-01

    Background Although substantiated by little evidence, concerns about zidovudine-related anaemia in pregnancy have influenced antiretroviral (ARV) regimen choice for preventing mother-to-child transmission of HIV-1, especially in settings where anaemia is common. Methods Eligible HIV-infected pregnant women in Burkina Faso, Kenya and South Africa were followed from 28 weeks of pregnancy until 12–24 months after delivery (n = 1070). Women with a CD4 count of 200-500cells/mm3 and gestational age 28–36 weeks were randomly assigned to zidovudine-containing triple-ARV prophylaxis continued during breastfeeding up to 6-months, or to zidovudine during pregnancy plus single-dose nevirapine (sd-NVP) at labour. Additionally, two cohorts were established, women with CD4 counts: <200 cells/mm3 initiated antiretroviral therapy, and >500 cells/mm3 received zidovudine during pregnancy plus sd-NVP at labour. Mild (haemoglobin 8.0-10.9 g/dl) and severe anaemia (haemoglobin < 8.0 g/dl) occurrence were assessed across study arms, using Kaplan-Meier and multivariable Cox proportional hazards models. Results At enrolment (corresponded to a median 32 weeks gestation), median haemoglobin was 10.3 g/dl (IQR = 9.2-11.1). Severe anaemia occurred subsequently in 194 (18.1%) women, mostly in those with low baseline haemoglobin, lowest socio-economic category, advanced HIV disease, prolonged breastfeeding (≥6 months) and shorter ARV exposure. Severe anaemia incidence was similar in the randomized arms (equivalence P-value = 0.32). After 1–2 months of ARV’s, severe anaemia was significantly reduced in all groups, though remained highest in the low CD4 cohort. Conclusions Severe anaemia occurs at a similar rate in women receiving longer triple zidovudine-containing regimens or shorter prophylaxis. Pregnant women with pre-existing anaemia and advanced HIV disease require close monitoring. Trial registration number ISRCTN71468401 PMID:24192332

  9. Mechanism of Action of Ribavirin on Bunyavirus Infected Cells

    DTIC Science & Technology

    1990-10-01

    presence of RTP. Combination of any of the ribavirin derivatives tested with 3’-azido-3’- deoxythymidine (AZT, zidovudine ) 5’-triphosphate resulted in an...Combination of any of the ribavirin derivatives tested with 3’-azido-3’- deoxythymidine (AZT, zidovudine ) 5’-triphosphate resulted in an increase of its anti...Larder, B.A., and Kemp, S.D. (1989). Multiple mutations in HIV-1 reverse transcriptase confer high-level resistance to zidovudine (AZT). Science 246, 1155

  10. Adeno-associated virus Rep-mediated targeting of integrase-defective retroviral vector DNA circles into human chromosome 19

    SciTech Connect

    Huang, Shuohao; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Adeno-associated virus (AAV) is capable of targeted integration in human cells. Black-Right-Pointing-Pointer Integrase-defective retroviral vector (IDRV) enables a circular DNA delivery. Black-Right-Pointing-Pointer A targeted integration system of IDRV DNA using the AAV integration mechanism. Black-Right-Pointing-Pointer Targeted IDRV integration ameliorates the safety concerns for retroviral vectors. -- Abstract: Retroviral vectors have been employed in clinical trials for gene therapy owing to their relative large packaging capacity, alterable cell tropism, and chromosomal integration for stable transgene expression. However, uncontrollable integrations of transgenes are likely to cause safety issues, such as insertional mutagenesis. A targeted transgene integration system for retroviral vectors, therefore, is a straightforward way to address the insertional mutagenesis issue. Adeno-associated virus (AAV) is the only known virus capable of targeted integration in human cells. In the presence of AAV Rep proteins, plasmids possessing the p5 integration efficiency element (p5IEE) can be integrated into the AAV integration site (AAVS1) in the human genome. In this report, we describe a system that can target the circular DNA derived from non-integrating retroviral vectors to the AAVS1 site by utilizing the Rep/p5IEE integration mechanism. Our results showed that after G418 selection 30% of collected clones had retroviral DNA targeted at the AAVS1 site.

  11. Mifepristone increases gamma-retroviral infection efficiency by enhancing integration of virus into the genome of infected cells

    PubMed Central

    Solodushko, Victor; Fouty, Brian

    2010-01-01

    Gamma-retroviruses are commonly used to deliver genes to cells. Previously we demonstrated that the synthetic anti-glucocorticoid and anti-progestin agent, mifepristone, increased gamma-retroviral infection efficiency in different target cells, independent of viral titer. In this paper, we examine how this occurs. We studied the effect of mifepristone on different steps of viral infection (viral entry, viral survival, viral DNA synthesis and retrovirus integration into the host genome) in three distinct retroviral backbones using different virus recognition receptors. We also tested the potential role of glucocorticoid and progesterone receptors in mediating mifepristone’s ability to increase gamma-retroviral infectivity. We show that mifepristone increases gamma-retroviral infection efficiency by facilitating viral integration into the host genome and that this effect appears to be due to mifepristone’s anti-glucocorticoid, but not its anti-progestin, activity. These results suggest that inhibition of the glucocorticoid receptor enhances retroviral integration into the host genome and indicates that cells may have a natural protection again retroviral infection that may be reduced by glucocorticoid receptor antagonists. PMID:20485384

  12. Dichotomy between T Cell and B Cell Tolerance to Neonatal Retroviral Infection Permits T Cell Therapy

    PubMed Central

    Mavrommatis, Bettina; Baudino, Lucie; Levy, Prisca; Merkenschlager, Julia; Eksmond, Urszula; Donnarumma, Tiziano; Young, George; Stoye, Jonathan

    2016-01-01

    Elucidation of the immune requirements for control or elimination of retroviral infection remains an important aim. We studied the induction of adaptive immunity to neonatal infection with a murine retrovirus, under conditions leading to immunological tolerance. We found that the absence of either maternal or offspring adaptive immunity permitted efficient vertical transmission of the retrovirus. Maternal immunodeficiency allowed the retrovirus to induce central Th cell tolerance in the infected offspring. In turn, this compromised the offspring’s ability to mount a protective Th cell–dependent B cell response. However, in contrast to T cells, offspring B cells were not centrally tolerized and retained their ability to respond to the infection when provided with T cell help. Thus, escape of retrovirus-specific B cells from deletional tolerance offers the opportunity to induce protective retroviral immunity by restoration of retrovirus-specific T cell help, suggesting similar T cell immunotherapies for persistent viral infections. PMID:27647833

  13. Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors

    SciTech Connect

    Lipnik, Karoline; Greco, Olga; Scott, Simon; Knapp, Elzbieta; Mayrhofer, Elisabeth; Rosenfellner, Doris; Guenzburg, Walter H.; Salmons, Brian; Hohenadl, Christine . E-mail: christine.hohenadl@vu-wien.ac.at

    2006-05-25

    To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector. Expression analyses in vitro, moreover, demonstrated a widely preserved mammary cell-specific promoter activity. For in vivo analyses, xenograft tumours consisting of infected human mammary adenocarcinoma cells were established in SCID/beige mice. Immunohistochemical analyses demonstrated a hypoxia-specific, markedly increased WAP promoter-driven expression in these tumours. Thus, this retroviral vector will facilitate a targeted gene therapeutic approach exploiting the unique environmental condition in solid tumours.

  14. Expression of human. alpha. sub 1 -antitrypsin in dogs after autologous transplantation of retroviral transduced hepatocytes

    SciTech Connect

    Kay, M.A.; Baley, P.; Rothenberg, S.; Leland, F; Fleming, L.; Ponder, K.P.; Liu, Tajen; Finegold, M.; Darlington, G.; Pokorny, W.; Woo, S.L.C. )

    1992-01-01

    The liver represents an excellent organ for gene therapy since many genetic disorders result from the deficiency of liver-specific gene products. The authors have previously demonstrated that transgenic mouse hepatocytes can be heterologously transplanted into congenic recipients where they survived indefinitely and continued to function as hepatocytes. Here they demonstrate the autologous transplantation of retrovirally transduced canine hepatocytes. In two animals they have transplanted hepatocytes transduced with a retroviral vector containing the human {alpha}{sub 1}-antitrypsin cDNA under transcriptional control of the cytomegalovirus promotor. Both animals had significant human {alpha}{sub 1}-antitrypsin in the serum for 1 month. The results suggest that gene therapy of hepatic deficiencies may be achieved by hepatocellular transplantation after genetic reconstruction with the use of promoters of cellular genes that are active in the normal liver.

  15. Evaluation of antioxidant defense systems in H4IIE cells infected with a retroviral vector.

    PubMed

    Oh, Soo Jin; Chae, Jooyoung; Zhu, Hongmei; Hien, Tran Thi; Lee, Kiho; Kim, Hwan Mook; Kang, Keon Wook; Song, Gyu Yong; Kang, Jong Seong; Kim, Bong-Hee; Kwon, Kwang-il; Kim, Sang Kyum

    2010-06-01

    Retroviral gene transfer technology is frequently used to establish stable transgenic cell lines. However, no studies to date have evaluated antioxidant defense systems in cells infected with retroviral particles. In the present study, we examined the effects of retroviral infection on antioxidant defense systems using H4IIE cells infected with a retrovirus that overexpresses green fluorescent protein (retro-H4IIE cells). Total oxyradical scavenging capacity and glutathione (GSH), malondialdehyde, and peroxide levels were not significantly altered in retro-H4IIE cells; however, retro-H4IIE cells showed a higher resistance against cytotoxicity, GSH depletion, and malondialdehyde elevation under H(2)O(2)-induced oxidative stress conditions. Immunoblot analysis showed that alpha-class GSH S-transferase (GST) was increased 2.5-fold in retro-H4IIE cells as compared with H4IIE cells; however, catalase, GSH peroxidase-1, peroxiredoxin-1, and thioredoxin-1 remained unaltered or slightly decreased. l-Buthionine-(S,R)-sulfoximine, a GSH synthesis inhibitor, and 1-chloro-2,4-dinitrobenzene, a GST substrate and competitive inhibitor, decreased the difference in H(2)O(2) responses between the two cell types. These results support the hypothesis that the resistance of retro-H4IIE cells to H(2)O(2) can be attributed to an increase in alpha-class GST expression, as levels of GSH and GSH peroxidase-1 were not altered. The present study suggests that antioxidant enzyme expression may change during the establishment of stable transformed cell lines using retroviral techniques.

  16. Statistical analysis of data from retroviral clonal experiments in the developing retina.

    PubMed

    Pounds, Stan; Dyer, Michael A

    2008-02-04

    Retroviral lineage studies have been widely used over the past decade to study retinal development in vivo and in explant culture [Donovan S.L., Dyer, M.A., 2006. Preparation and Square Wave Electroporation of Retinal Explant Cultures, Nature Protocols 1, 2710-2718; Donovan, S.L., Schweers, B., Martins, R., Johnson D., Dyer, M.A., 2001. Compensation by tumor suppressor genes during retinal development in mice and humans, BMC Biol 4 , 14; Dyer M.A., Cepko, C.L., 2001. p27Kip1 and p57Kip2 regulate proliferation in distinct retinal progenitor cell populations, J. of Neurosci 21, 4259-4271; Dyer M.A., Cepko, C.L., 2000. p57(Kip2) regulates progenitor cell proliferation and amacrine interneuron development in the mouse retina, Development 127, 3593-3605; Dyer, M.A., Livesey, F.J., Cepko C.L., Oliver, G., 2003. Prox1 function controls progenitor cell proliferation and horizontal cell genesis in the mammalian retina, Nat Genet 34, 53-58]. These approaches can provide important data on the proliferation, cell fate specification, differentiation and survival of individual neurons and glia derived from single infected retinal progenitor cells. In some experiments, these parameters are compared in retinae from animals with different targeted deletions or transgenes. Alternatively, the effect of ectopic expression of virally encoded transgenes may be studied at the level of individual retinal progenitor cells in vivo and in explant culture. One of the challenges with interpreting retroviral lineage studies is determining the statistical significance of differences in the proliferation, cell fate specification, differentiation of survival of retinal progenitor cells between experimental and control samples. In this study, we provide a clear step-by-step guide to the application of statistical methods to retroviral lineage analyses actual data sets. We anticipate that this will serve as a guide for future statistical analyses of retroviral lineage studies and will help to

  17. Increased immunoglobulin G, but not M, binding to endogenous retroviral antigens in HIV-1 infected persons.

    PubMed

    Lawoko, A; Johansson, B; Rabinayaran, D; Pipkorn, R; Blomberg, J

    2000-12-01

    The modes of interaction between products of human endogenous retroviral (HERV) sequences and the immune system are largely unknown. In HIV infected persons, an exogenous retrovirus adds further complexity to the situation. Therefore, 14 synthetic peptides with sequences derived from conserved regions of various endogenous retroviruses (ERVs) and from related exogenous retroviruses were used to search for IgG and IgM antibodies that bind to such antigens in 15 HIV-1 seropositive and 17 seronegative immunosuppressed patients. IgG binding to three peptides, namely, the C-terminal half of murine leukemia virus (MLV) capsid protein, the conserved portion of HERV-H transmembrane protein, and the Pol region of human mouse mammary tumor virus (MMTV)-like (HML3) sequence, was observed in both groups. Binding was, however, more frequent and more firm in HIV-1 positive samples (P<0.0001, Wilcoxon rank sum test). IgM binding to the same peptides showed no significant differentiation between the two groups of patients. Binding to both immunoglobulin isotypes was sometimes variable over time in both groups. No correlation of either IgG or IgM peptide binding with progression to AIDS in HIV-1 infected individuals was observed. Inhibition studies using analogous endogenous and exogenous retroviral peptides, including HIV-1, demonstrated specificity of the IgG antibodies for a narrow range of MLV- and MMTV-like retroviral antigens, and excluded cross-reactivity of antibodies to HIV-1 as a cause of these observations. Thus, unlike IgG, IgM binding to retroviral antigens was ubiquitous. It is suggested that anti-HERV IgM belong to a class of natural antibodies and might serve as primers in the mediation of humoral immune responses to more or less related exogenous retroviruses. Increased IgG binding in HIV-1 infected individuals could result from such priming, or reflect higher HERV antigen expression.

  18. Gene transfer in ovarian cancer cells: a comparison between retroviral and lentiviral vectors.

    PubMed

    Indraccolo, Stefano; Habeler, Walter; Tisato, Veronica; Stievano, Laura; Piovan, Erich; Tosello, Valeria; Esposito, Giovanni; Wagner, Ralf; Uberla, Klaus; Chieco-Bianchi, Luigi; Amadori, Alberto

    2002-11-01

    Local gene therapy could be a therapeutic option for ovarian carcinoma, a life-threatening malignancy, because of disease containment within the peritoneal cavity in most patients. Lentiviral vectors, which are potentially capable of stable transgene expression, may be useful to vehicle therapeutic molecules requiring long-term production in these tumors. To investigate this concept, we used lentiviral vectors to deliver the enhanced green fluorescent protein (EGFP) gene to ovarian cancer cells. Their efficiency of gene transfer was compared with that of a retroviral vector carrying the same envelope. In vitro, both vectors infected ovarian cancer cells with comparable efficiency under standard culture conditions; however, the lentiviral vector was much more efficient in transducing growth-arrested cells when compared with the retroviral vector. Gene transfer was fully neutralized by an anti-VSV-G antibody, and in vitro stability was similar. In vivo, the lentiviral vector delivered the transgene 10-fold more efficiently to ovarian cancer cells growing i.p. in SCID mice, as evaluated by real-time PCR analysis of the tumors. Confocal microscopy analysis of tumor sections showed a dramatic difference at the level of transgene expression, because abundant EGFP(+) cells were detected only in mice receiving the lentiviral vector. Quantitative analysis by flow cytometry confirmed this and indicated 0.05 and 5.6% EGFP(+) tumor cells after administration of the retroviral and lentiviral vector, respectively. Injection of ex vivo transduced tumor cells, sorted for EGFP expression, indicated that the lentiviral vector was considerably more resistant to in vivo silencing in comparison with the retroviral vector. Finally, multiple administrations of a murine IFN-alpha(1)-lentiviral vector to ovarian carcinoma-bearing mice significantly prolonged the animals' survival, indicating the therapeutic efficacy of this approach. These findings indicate that lentiviral vectors deserve

  19. Retroviral envelope gene captures and syncytin exaptation for placentation in marsupials

    PubMed Central

    Cornelis, Guillaume; Vernochet, Cécile; Carradec, Quentin; Souquere, Sylvie; Mulot, Baptiste; Catzeflis, François; Nilsson, Maria A.; Menzies, Brandon R.; Renfree, Marilyn B.; Pierron, Gérard; Zeller, Ulrich; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

    2015-01-01

    Syncytins are genes of retroviral origin captured by eutherian mammals, with a role in placentation. Here we show that some marsupials—which are the closest living relatives to eutherian mammals, although they diverged from the latter ∼190 Mya—also possess a syncytin gene. The gene identified in the South American marsupial opossum and dubbed syncytin-Opo1 has all of the characteristic features of a bona fide syncytin gene: It is fusogenic in an ex vivo cell–cell fusion assay; it is specifically expressed in the short-lived placenta at the level of the syncytial feto–maternal interface; and it is conserved in a functional state in a series of Monodelphis species. We further identify a nonfusogenic retroviral envelope gene that has been conserved for >80 My of evolution among all marsupials (including the opossum and the Australian tammar wallaby), with evidence for purifying selection and conservation of a canonical immunosuppressive domain, but with only limited expression in the placenta. This unusual captured gene, together with a third class of envelope genes from recently endogenized retroviruses—displaying strong expression in the uterine glands where retroviral particles can be detected—plausibly correspond to the different evolutionary statuses of a captured retroviral envelope gene, with only syncytin-Opo1 being the present-day bona fide syncytin active in the opossum and related species. This study would accordingly recapitulate the natural history of syncytin exaptation and evolution in a single species, and definitely extends the presence of such genes to all major placental mammalian clades. PMID:25605903

  20. Murine leukemias with retroviral insertions at Lmo2 are predictive of the leukemias induced in SCID-X1 patients following retroviral gene therapy.

    PubMed

    Davé, Utpal P; Akagi, Keiko; Tripathi, Rati; Cleveland, Susan M; Thompson, Mary A; Yi, Ming; Stephens, Robert; Downing, James R; Jenkins, Nancy A; Copeland, Neal G

    2009-05-01

    Five X-linked severe combined immunodeficiency patients (SCID-X1) successfully treated with autologous bone marrow stem cells infected ex vivo with an IL2RG-containing retrovirus subsequently developed T-cell leukemia and four contained insertional mutations at LMO2. Genetic evidence also suggests a role for IL2RG in tumor formation, although this remains controversial. Here, we show that the genes and signaling pathways deregulated in murine leukemias with retroviral insertions at Lmo2 are similar to those deregulated in human leukemias with high LMO2 expression and are highly predictive of the leukemias induced in SCID-X1 patients. We also provide additional evidence supporting the notion that IL2RG and LMO2 cooperate in leukemia induction but are not sufficient and require additional cooperating mutations. The highly concordant nature of the genetic events giving rise to mouse and human leukemias with mutations at Lmo2 are an encouraging sign to those wanting to use mice to model human cancer and may help in designing safer methods for retroviral gene therapy.

  1. Suppression of retroviral propagation and disease by suramin in murine systems.

    PubMed Central

    Ruprecht, R M; Rossoni, L D; Haseltine, W A; Broder, S

    1985-01-01

    Retroviral propagation crucially depends on reverse transcriptase (RT). We have developed murine models to test the biological effectiveness of the RT inhibitor suramin. The drug was active in our assay system, which includes (i) inhibition of RT activity in the murine T-cell tropic virus SL3-3 and Rauscher murine leukemia virus (MuLV), (ii) inhibition of plaque formation in the XC plaque assay, (iii) inhibition of viral infection of cultured murine T cells, and (iv) inhibition of splenomegaly induced by Rauscher MuLV in BALB/c mice. Suramin decreases viral titers significantly, even if started 36 hr after infection. Viral titers and number of infected cells increased to control levels after removal of the drug. BALB/c mice treated i.v. with 40 mg of suramin per kg twice per week following infection with Rauscher MuLV showed a 35% decrease in splenomegaly. Suramin is an active antiretroviral agent whose effect on retroviral propagation is reversible. We conclude that it acts as a virustatic drug and that long-term administration of suramin will be necessary if it is used for experimental treatment of human retroviral illnesses such as the acquired immune deficiency syndrome. PMID:2415971

  2. Novel Endogenous Type D Retroviral Particles Expressed at High Levels in a SCID Mouse Thymic Lymphoma

    PubMed Central

    Ristevski, Sika; Purcell, Damian F. J.; Marshall, John; Campagna, Daniella; Nouri, Sara; Fenton, Simon P.; McPhee, Dale A.; Kannourakis, George

    1999-01-01

    A xenograft model of the human disease Langerhans cell histiocytosis (LCH) was investigated with severe combined immunodeficiency (SCID) mice. Transplantation of human LCH biopsy material into SCID mice resulted in the generation of mouse tumors resembling lymphomas. A thymoma cell line (ThyE1M6) was generated from one of these mice and found to display significant levels of Mg2+-dependent reverse transcriptase activity. Electron microscopy revealed particles with type D retroviral morphology budding from ThyE1M6 cells at a high frequency, whereas control cultures were negative. Reverse transcription-PCR of virion RNA with degenerate primers for conserved regions of various mouse, human, and primate retroviruses amplified novel sequences related to primate type D retroviruses, murine intracisternal A particles, Jaagsiekte sheep retrovirus, and murine long interspersed nuclear elements but not other retroviral classes. We demonstrate that these sequences represent a novel group of endogenous retroviruses expressed at low levels in mice but expressed at high levels in the ThyE1M6 cell line. Furthermore, we propose that the activation of endogenous retroviral elements may be associated with a high incidence of thymomas in SCID mice. PMID:10233925

  3. Comparing the landcapes of common retroviral insertion sites across tumor models

    NASA Astrophysics Data System (ADS)

    Weishaupt, Holger; Čančer, Matko; Engström, Cristopher; Silvestrov, Sergei; Swartling, Fredrik J.

    2017-01-01

    Retroviral tagging represents an important technique, which allows researchers to screen for candidate cancer genes. The technique is based on the integration of retroviral sequences into the genome of a host organism, which might then lead to the artificial inhibition or expression of proximal genetic elements. The identification of potential cancer genes in this framework involves the detection of genomic regions (common insertion sites; CIS) which contain a number of such viral integration sites that is greater than expected by chance. During the last two decades, a number of different methods have been discussed for the identification of such loci and the respective techniques have been applied to a variety of different retroviruses and/or tumor models. We have previously established a retrovirus driven brain tumor model and reported the CISs which were found based on a Monte Carlo statistics derived detection paradigm. In this study, we consider a recently proposed alternative graph theory based method for identifying CISs and compare the resulting CIS landscape in our brain tumor dataset to those obtained when using the Monte Carlo approach. Finally, we also employ the graph-based method to compare the CIS landscape in our brain tumor model with those of other published retroviral tumor models.

  4. Cryo-EM reveals a novel octameric integrase structure for β-retroviral intasome function

    PubMed Central

    Ballandras-Colas, Allison; Brown, Monica; Cook, Nicola J.; Dewdney, Tamaria G.; Demeler, Borries; Cherepanov, Peter; Lyumkis, Dmitry; Engelman, Alan N.

    2016-01-01

    Retroviral integrase (IN) catalyzes the integration of viral DNA (vDNA) into host target (tDNA), which is an essential step in the lifecycle of all retroviruses1. Prior structural characterization of IN-vDNA complexes, or intasomes, from the spumavirus prototype foamy virus (PFV) revealed a functional IN tetramer2–5, and it is generally believed that intasomes derived from other retroviral genera will employ tetrameric IN6–9. However, the intasomes of orthoretroviruses, which include all known pathogenic species, have not been characterized structurally. Using single-particle cryo-electron microscopy (cryo-EM) and X-ray crystallography, we determine here an unexpected octameric IN architecture for the β-retrovirus mouse mammary tumor virus (MMTV) intasome. The structure is composed of two core IN dimers, which interact with the vDNA ends and structurally mimic the PFV IN tetramer, and two flanking IN dimers that engage the core structure via their IN C-terminal domains (CTDs). Contrary to the belief that tetrameric IN components are sufficient to catalyze integration, the flanking IN dimers were necessary for MMTV IN activity. The IN octamer solves a conundrum for the β- as well as α-retroviruses by providing critical CTDs to the intasome core that cannot be provided in cis due to evolutionarily restrictive catalytic core domain (CCD)-CTD linker regions. The octameric architecture of the MMTV intasome provides a new paradigm for the structural basis of retroviral DNA integration. PMID:26887496

  5. Cross- and Co-Packaging of Retroviral RNAs and Their Consequences

    PubMed Central

    Ali, Lizna M.; Rizvi, Tahir A.; Mustafa, Farah

    2016-01-01

    Retroviruses belong to the family Retroviridae and are ribonucleoprotein (RNP) particles that contain a dimeric RNA genome. Retroviral particle assembly is a complex process, and how the virus is able to recognize and specifically capture the genomic RNA (gRNA) among millions of other cellular and spliced retroviral RNAs has been the subject of extensive investigation over the last two decades. The specificity towards RNA packaging requires higher order interactions of the retroviral gRNA with the structural Gag proteins. Moreover, several retroviruses have been shown to have the ability to cross-/co-package gRNA from other retroviruses, despite little sequence homology. This review will compare the determinants of gRNA encapsidation among different retroviruses, followed by an examination of our current understanding of the interaction between diverse viral genomes and heterologous proteins, leading to their cross-/co-packaging. Retroviruses are well-known serious animal and human pathogens, and such a cross-/co-packaging phenomenon could result in the generation of novel viral variants with unknown pathogenic potential. At the same time, however, an enhanced understanding of the molecular mechanisms involved in these specific interactions makes retroviruses an attractive target for anti-viral drugs, vaccines, and vectors for human gene therapy. PMID:27727192

  6. Amperometric sensing of anti-HIV drug zidovudine on Ag nanofilm-multiwalled carbon nanotubes modified glassy carbon electrode.

    PubMed

    Rafati, Amir Abbas; Afraz, Ahmadreza

    2014-06-01

    The zidovudine (ZDV) is the first drug approved for the treatment of HIV virus infection. The detection and determination of this drug are very importance in human serum because of its undesirable effects. A new ZDV sensor was fabricated on the basis of nanocomposite of silver nanofilm (Ag-NF) and multiwalled carbon nanotubes (MWCNTs) immobilized on glassy carbon electrode (GCE). The modified electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), cyclic voltammetry (CV), and linear sweep voltammetry (LSV) techniques. Results showed that the electrodeposited silver has a nanofilm structure and further electrochemical studies showed that the prepared nanocomposite has high electrocatalytic activity and is appropriate for using in sensors. The amperometric technique under optimal conditions is used for the determination of ZDV ranging from 0.1 to 400ppm (0.37μM-1.5mM) with a low detection limit of 0.04ppm (0.15μM) (S/N=3) and good sensitivity. The prepared sensor possessed accurate and rapid response to ZDV and shows an average recovery of 98.6% in real samples.

  7. Prevalence and risk factors of low bone mineral density in Korean HIV-infected patients: impact of abacavir and zidovudine.

    PubMed

    Kim, Hee-Sung; Chin, Bum Sik; Shin, Hyoung-Shik

    2013-06-01

    Low bone mineral density (BMD) is common in HIV-infected patients. We aimed to describe the prevalence of low BMD and risk factors in Korean HIV-infected patients and to assess the effects of antiretroviral therapy (ART) on BMD. We retrospectively evaluated 224 HIV infected-patients. The prevalence of osteopenia and osteoporosis were 41.5% and 12.9%. These were much higher in 53 patients aged 50 yr and older (52.8% and 34.0%). Older age, lower body mass index, and ART > 3 months were independent risk factors for low BMD. Osteoporosis was more prevalent in patients on the abacavir-based regimen for < 1 yr than ≥ 1 yr; however, it was more prevalent in patients on the zidovudine-based regimen for ≥ 1 yr than < 1 yr (P = 0.017). Osteoporosis in patients on the abacavir-based regimen was more common in the spine than in the femur (P = 0.01). Given such a high prevalence of low BMD, close monitoring of BMD for HIV-infected patients on ART is required. The different prevalence of osteoporosis over time and affected areas between two regimens suggest they may play roles in different mechanisms in bone loss.

  8. Factors associated with zidovudine receipt and prenatal care among HIV-infected pregnant women in New Jersey.

    PubMed

    Abatemarco, Diane J; Catov, Janet M; Cross, Helene; Delnevo, Cristine; Hausman, Alice

    2008-08-01

    Despite reductions in perinatal HIV transmission, cases continue to occur. To determine factors associated with zidovudine (ZDV) receipt among HIV-infected pregnant women we merged three data sets for women in New Jersey in 1995-1997, identifying 395 HIV-infected pregnant women. Half received two arms of ZDV prophylaxis. Attendance at five or more prenatal visits was the strongest independent factor related to ZDV receipt (OR 6.37, 95% CI 3.84, 10.57). Half (49.0%) had limited prenatal care. AIDS diagnosis, race/ethnicity, and drug use were also independently related to ZDV receipt. Post hoc analysis revealed that being unmarried, Black, multiparous, having no insurance, and illegal drug use were associated with limited prenatal care. Although the U.S. has seen reductions in HIV perinatal transmission, our research showed that HIV-infected women who did not get prenatal care were less likely to receive two arms of ZDV prophylaxis. A wide public health net that brings all women into care is necessary to reduce perinatal transmission further.

  9. Lack of Pharmacokinetic Interaction between Amdoxovir and Reduced- and Standard-Dose Zidovudine in HIV-1-Infected Individuals▿

    PubMed Central

    Hurwitz, Selwyn J.; Asif, Ghazia; Fromentin, Emilie; Tharnish, Phillip M.; Schinazi, Raymond F.

    2010-01-01

    Amdoxovir (AMDX) inhibits HIV-1 containing the M184V/I mutation and is rapidly absorbed and deaminated to its active metabolite, β-d-dioxolane guanosine (DXG). DXG is synergistic with zidovudine (ZDV) in HIV-1-infected primary human lymphocytes. A recent in silico pharmacokinetic (PK)/enzyme kinetic study suggested that ZDV at 200 mg twice a day (b.i.d.) may reduce toxicity without compromising efficacy relative to the standard 300-mg b.i.d. dose. Therefore, an intense PK clinical study was conducted using AMDX/placebo, with or without ZDV, in 24 subjects randomized to receive oral AMDX at 500 mg b.i.d., AMDX at 500 mg plus ZDV at 200 or 300 mg b.i.d., or ZDV at 200 or 300 mg b.i.d. for 10 days. Full plasma PK profiles were collected on days 1 and 10, and complete urine sampling was performed on day 9. Plasma and urine concentrations of AMDX, DXG, ZDV, and ZDV-5′-O-glucuronide (GZDV) were measured using a validated liquid chromatography-tandem mass spectrometry method. Data were analyzed using noncompartmental methods, and multiple comparisons were performed on the log-transformed parameters, at steady state. Coadministration of AMDX with ZDV did not significantly change either of the plasma PK parameters or percent recovery in the urine of AMDX, DXG, or ZDV/GZDV. Larger studies with AMDX/ZDV, with a longer duration, are warranted. PMID:20038617

  10. Use of accelerator mass spectrometry to measure the pharmacokinetics and peripheral blood mononuclear cell concentrations of zidovudine.

    PubMed

    Vuong, Le T; Ruckle, Jon L; Blood, Arlin B; Reid, Michael J; Wasnich, Richard D; Synal, Hans-Arno; Dueker, Stephen R

    2008-07-01

    The remarkable sensitivity of accelerator mass spectrometry (AMS) is finding many new applications in pharmacology. In this study AMS was used to measure [(14)C]-Zidovudine (ZDV) concentrations at the drug's site of action (peripheral blood mononuclear cells, PBMCs) following a dose of 520 ng (less than one-millionth of the standard daily dose) to a healthy volunteer. In addition, the pharmacokinetics of this microdose were determined and compared to previously published parameters for therapeutic doses. Microdose ZDV pharmacokinetic parameters fell within reported 95% confidence intervals or standard deviations of most previously published values for therapeutic doses. Blood, urine, stool, saliva, and isolated PBMCs were collected periodically through 96 h postdose and analyzed for ZDV and metabolite concentrations. The results showed that ZDV is rapidly absorbed and eliminated, has one major metabolite, and is sequestered in PBMCs. (14)C mass balance assessments indicated a significant portion of ZDV remained after 96 h with a much prolonged elimination half-life. Results of this study demonstrate the usefulness of microdosing and AMS as a tool for studying the pharmacokinetic characteristics, including PBMC concentrations, of ZDV and underscore the value of AMS as a tool with which to perform pharmacokinetic and mass balance studies using trace amounts of radiolabeled compound.

  11. Using RT-prone recombination to promote re-building of complete retroviral vectors from two defective precursors: low efficiency and sequence specificities.

    PubMed

    Bru, Thierry; Galetto, Román; Piver, Eric; Collin, Christine; Negroni, Matteo; Pagès, Jean-Christophe

    2007-06-01

    Retroviral recombination has been suggested as a useful way to modify retroviral vectors. The possibility to combine two multiply deleted retroviral vectors into a novel vector was evaluated. To investigate this possibility we have constructed two defective vectors containing a shared internal ribosome entry site (IRES). The IRES was selected for its complex secondary structure, a feature described to favour retroviral recombination. The IRES was expected to promote a recombination event leading to the formation of a unique, functional retroviral vector. By supporting expression of two transgenes from a single promoter, this sequence was also expected to allow straightforward detection of the recombination event. The present data confirms the achievement of recombination-dependent rescue, albeit at low efficiency. Unexpectedly, a preferential use of the packaging signal (Psi) for recombination was observed, as compared to the IRES. Together these observations mitigate the idea of using this technique for the design of retroviral vectors.

  12. TRIM5 Retroviral Restriction Activity Correlates with the Ability To Induce Innate Immune Signaling

    PubMed Central

    Lascano, Josefina; Uchil, Pradeep D.; Mothes, Walther

    2015-01-01

    ABSTRACT Host restriction factor TRIM5 inhibits retroviral transduction in a species-specific manner by binding to and destabilizing the retroviral capsid lattice before reverse transcription is completed. However, the restriction mechanism may not be that simple since TRIM5 E3 ubiquitin ligase activity, the proteasome, autophagy, and TAK1-dependent AP-1 signaling have been suggested to contribute to restriction. Here, we show that, among a panel of seven primate and Carnivora TRIM5 orthologues, each of which has potential for potent retroviral restriction activity, all activated AP-1 signaling. In contrast, TRIM family paralogues most closely related to TRIM5 did not. While each primate species has a single TRIM5 gene, mice have at least seven TRIM5 homologues that cluster into two groups, Trim12a, -b, and -c and Trim30a, -b, -c, and -d. The three Trim12 proteins activated innate immune signaling, while the Trim30 proteins did not, though none of the murine Trim5 homologues restricted any of a panel of cloned retroviruses. To determine if any mouse TRIM5 homologues had potential for restriction activity, each was fused to the human immunodeficiency virus type 1 (HIV-1) CA binding protein cyclophilin A (CypA). The three Trim12-CypA fusions all activated AP-1 and restricted HIV-1 transduction, whereas the Trim30-CypA fusions did neither. AP-1 activation and HIV-1 restriction by the Trim12-CypA fusions were inhibited by disruption of TAK1. Overall then, these experiments demonstrate that there is a strong correlation between TRIM5 retroviral restriction activity and the ability to activate TAK1-dependent innate immune signaling. IMPORTANCE The importance of retroviruses for the evolution of susceptible host organisms cannot be overestimated. Eight percent of the human genome is retrovirus sequence, fixed in the germ line during past infection. Understanding how metazoa protect their genomes from mutagenic retrovirus infection is therefore of fundamental importance to

  13. Positive Selection of Iris, a Retroviral Envelope–Derived Host Gene in Drosophila melanogaster

    PubMed Central

    Malik, Harmit S; Henikoff, Steven

    2005-01-01

    Eukaryotic genomes can usurp enzymatic functions encoded by mobile elements for their own use. A particularly interesting kind of acquisition involves the domestication of retroviral envelope genes, which confer infectious membrane-fusion ability to retroviruses. So far, these examples have been limited to vertebrate genomes, including primates where the domesticated envelope is under purifying selection to assist placental function. Here, we show that in Drosophila genomes, a previously unannotated gene (CG4715, renamed Iris) was domesticated from a novel, active Kanga lineage of insect retroviruses at least 25 million years ago, and has since been maintained as a host gene that is expressed in all adult tissues. Iris and the envelope genes from Kanga retroviruses are homologous to those found in insect baculoviruses and gypsy and roo insect retroviruses. Two separate envelope domestications from the Kanga and roo retroviruses have taken place, in fruit fly and mosquito genomes, respectively. Whereas retroviral envelopes are proteolytically cleaved into the ligand-interaction and membrane-fusion domains, Iris appears to lack this cleavage site. In the takahashii/suzukii species groups of Drosophila, we find that Iris has tandemly duplicated to give rise to two genes (Iris-A and Iris-B). Iris-B has significantly diverged from the Iris-A lineage, primarily because of the “invention” of an intron de novo in what was previously exonic sequence. Unlike domesticated retroviral envelope genes in mammals, we find that Iris has been subject to strong positive selection between Drosophila species. The rapid, adaptive evolution of Iris is sufficient to unambiguously distinguish the phylogenies of three closely related sibling species of Drosophila (D. simulans, D. sechellia, and D. mauritiana), a discriminative power previously described only for a putative “speciation gene.” Iris represents the first instance of a retroviral envelope–derived host gene outside

  14. TRIM5α Degradation via Autophagy Is Not Required for Retroviral Restriction.

    PubMed

    Imam, Sabrina; Talley, Sarah; Nelson, Rachel S; Dharan, Adarsh; O'Connor, Christopher; Hope, Thomas J; Campbell, Edward M

    2016-01-13

    TRIM5α is an interferon-inducible retroviral restriction factor that prevents infection by inducing the abortive disassembly of capsid cores recognized by its C-terminal PRY/SPRY domain. The mechanism by which TRIM5α mediates the disassembly of viral cores is poorly understood. Previous studies demonstrated that proteasome inhibitors abrogate the ability of TRIM5α to induce premature core disassembly and prevent reverse transcription; however, viral infection is still inhibited, indicating that the proteasome is partially involved in the restriction process. Alternatively, we and others have observed that TRIM5α associates with proteins involved in autophagic degradation pathways, and one recent study found that autophagic degradation is required for the restriction of retroviruses by TRIM5α. Here, we show that TRIM5α is basally degraded via autophagy in the absence of restriction-sensitive virus. We observe that the autophagy markers LC3b and lysosome-associated membrane protein 2A (LAMP2A) localize to a subset of TRIM5α cytoplasmic bodies, and inhibition of lysosomal degradation with bafilomycin A1 increases this association. To test the requirement for macroautophagy in restriction, we examined the ability of TRIM5α to restrict retroviral infection in cells depleted of the autophagic mediators ATG5, Beclin1, and p62. In all cases, restriction of retroviruses by human TRIM5α, rhesus macaque TRIM5α, and owl monkey TRIM-Cyp remained potent in cells depleted of these autophagic effectors by small interfering RNA (siRNA) knockdown or clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 genome editing. Collectively, these results are consistent with observations that the turnover of TRIM5α proteins is sensitive to autophagy inhibition; however, the data presented here do not support observations that the inhibition of autophagy abrogates retroviral restriction by TRIM5 proteins. Restriction factors are a class of proteins that inhibit

  15. Mean Corpuscular Volume as a Marker for Adherence to Zidovudine-Containing Therapy in HIV-Infected Adults

    PubMed Central

    Mugisha, Joseph O; Donegan, Katherine; Fidler, Sarah; Ramjee, Gita; Hodson, Andrew; Dunn, David T; Porter, Kholoud; Kaleebu, Pontiano

    2012-01-01

    Objectives: To assess whether mean corpuscular volume (MCV) is useful in detecting non-adherence to AZTcontaining therapy. Design: Observational study within randomised controlled trial. Methods: We combined data from two treatment arms in SPARTAC, an RCT of short-course cART in primary HIV infection, classifying participants as responders (HIV-RNA decrease ≥1 log10 or reaching <400copies/ml) or nonresponders following cART initiation. We assessed the sensitivity and specificity of using different percentage increases in MCV for accurately differentiating between responders and non-responders. We further examined changes in MCV levels up to 24 weeks after protocol-indicated cART cessation. Results: Of 119 participants included in this analysis, 73 (61%) were women, 71 of whom were randomised in Africa. Ninety-eight (88%) and 84 (85%) were classified as responders at 4 and 12 weeks respectively following cART initiation. MCV increased by a mean 3% and 1% at week 4, and 14% and <1% at 12 weeks for responders and non-responders. A 2% MCV increase at 4 weeks had 62% sensitivity and specificity for identifying virological response. At 12 weeks, an 8% increase had 89% sensitivity and specificity. In responders, MCV remained lower for individuals in African compared to non-African sites throughout and rose from 85 vs 90 fL at cART start to 96 vs 103 fL at 12 weeks post-initiation then fell to 88 vs 93 fL and 86 vs 89 fL at 12 and 48 weeks post-cessation. Conclusion: In low-income countries, where HIV RNA may be unavailable, 12-weekly MCV measurements may be useful in monitoring adherence to AZT-containing regimens. PMID:22715353

  16. Interindividual Variability in Pharmacokinetics of Generic Nucleoside Reverse Transcriptase Inhibitors in TB/HIV Co-infected Ghanaian Patients: UGT2B7*1C is Associated with Faster Zidovudine Clearance and Glucuronidation

    PubMed Central

    Kwara, Awewura; Lartey, Margaret; Boamah, Isaac; Rezk, Naser L.; Oliver-Commey, Joseph; Kenu, Ernest; Kashuba, Angela D.M.; Court, Michael H.

    2009-01-01

    There are limited data on the pharmacokinetics of generic nucleoside reverse transcriptase inhibitors (NRTIs) in native African populations, where they are commonly used. We characterized the pharmacokinetics of lamivudine (n=27), zidovudine (n=16) and stavudine (n=11) in HIV/TB co-infected Ghanaians, and evaluated associations between zidovudine metabolism and UDP-glucuronosyltransferase (UGT) 2B7 polymorphisms. Lamivudine, zidovudine, and stavudine apparent oral clearance (CL/F) values [mean±SD (CV%)] were 7.3±2.8 (39%), 31.9±33.6 (106%), and 16.4±5.8 (35%) mL/min/kg, respectively, whereas half-life values were 4.2±1.9 (46%), 8.1±7.9 (98%), and 1.5±1.0 (65%) hr, respectively. Zidovudine CL/F was 196% higher (P=0.004) in UGT2B7*1c (c.735A>G) carriers versus non-carriers. This was confirmed using human liver bank samples (n=52), which showed 48% higher (P=0.020) zidovudine glucuronidation and 33% higher (P=0.015) UGT2B7 protein in UGT2B7*1c carriers versus non-carriers. In conclusion, generic NRTI pharmacokinetics in HIV/TB co-infected Ghanaians are similar to other populations, while the UGT2B7*1c polymorphism may explain in part relatively high interindividual variability in zidovudine clearance. PMID:19628728

  17. Simultaneous determination of lamivudine, lopinavir, ritonavir, and zidovudine concentration in plasma of HIV-infected patients by HPLC-MS/MS.

    PubMed

    Notari, Stefania; Sergi, Manuel; Montesano, Camilla; Ivanovic, Jelena; Narciso, Pasquale; Pucillo, Leopoldo P; Ascenzi, Paolo

    2012-05-01

    The nucleoside reverse transcriptase inhibitors lamivudine and zidovudine and the protease inhibitors lopinavir and ritonavir are currently used in anti-human immunodeficiency virus (HIV) therapy. Here, a high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method, using a hybrid quadrupole time-of-flight mass analyzer, is reported for the simultaneous quantification of lamivudine, lopinavir, ritonavir, and zidovudine in plasma of HIV-infected patients. The volume of plasma sample was 600 μL. Plasma samples were extracted by solid-phase using 1 cc Oasis HLB Cartridge (divinylbenzene and N-vinylpyrrolidone) and evaporated in a water bath under nitrogen stream. The extracted samples were reconstituted with 100-μL methanol. Five microliters of the reconstituted samples were injected into a HPLC-MS/MS apparatus, and the analytes were eluted on a Vydac column (250 × 1.0 mm i.d.) filled with 3-μm C(18) particles. The mobile phase was delivered at 70 μL/min with a linear gradient elution, both acetonitrile and ultrapure water solvents contained 0.2% formic acid. The calibration curves were linear from 0.47 to 20 ng/mL. The absolute recovery ranged between 91 and 107%. The minimal concentration of lamivudine, lopinavir, ritonavir, and zidovudine detectable by HPLC-MS/MS is 0.47, 0.28, 0.30, and 0.66 ng/mL, respectively. The great advantage of the new HPLC-MS/MS method here reported is the possibility to achieve a very high specificity toward the selected anti-HIV drugs, despite the simple and rapid sample preparation. Moreover, this method is easily extendible to the analysis of co-administrated drugs. Copyright © 2012 Wiley Periodicals, Inc.

  18. Zidovudine-induced nail hyper-pigmentation in 45-year-old women prescribed for HIV/tuberculosis co-infection.

    PubMed

    Tandon, Vishal R; Sadiq, Shamiya; Khajuria, Vijay; Mahajan, Annil; Sharma, Sudhaa; Gillani, Zahid

    2016-01-01

    Zidovudine is an important component of first-line antiretroviral treatment regimens used to manage HIV and tuberculosis (TB) co-infection. Nail pigmentation is documented both in adult as well as pediatric HIV patients, but to the best of our knowledge, it has not been reported in 45-year-old women of HIV/TB co-infection. Such an adverse drugs reactions (ADR), although is harmless and reversible, psychological aspects of such ADR may be immense to the extent that it can negatively affect the compliance and result in therapeutic failure. Thus, it is worth reporting.

  19. Nevirapine-Resistant HIV-1 DNA in Breast Milk After Single-Dose Nevirapine With or Without Zidovudine for Prevention of Mother-to-Child Transmission.

    PubMed

    Gantt, Soren; Payant, Rachel; Carlsson, Jacquelyn; Micek, Mark A; Blanco, Ana Judith; Beck, Ingrid A; Matunha, Laurinda; Montoya, Pablo; Matediana, Eduardo; Gloyd, Stephen; Frenkel, Lisa M

    2012-09-01

    Among 30 human immunodeficiency virus type 1 (HIV-1)-infected women who received single-dose nevirapine (NVP), 17 (57%) had NVP-resistant HIV-1 detected in breast milk. NVP resistance in breast milk persisted for at least 8 months postpartum and was apparently transmitted to at least 1 infant. NVP resistance was detected less often in women who also received zidovudine. © The Author 2012. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Stability of Retroviral Vectors Against Ultracentrifugation Is Determined by the Viral Internal Core and Envelope Proteins Used for Pseudotyping.

    PubMed

    Kim, Soo-Hyun; Lim, Kwang-Il

    2017-05-31

    Retroviral and lentiviral vectors are mostly pseudotyped and often purified and concentrated via ultracentrifugation. In this study, we quantified and compared the stabilities of retroviral [murine leukemia virus (MLV)-based] and lentiviral [human immunodeficiency virus (HIV)-1-based] vectors pseudotyped with relatively mechanically stable envelope proteins, vesicular stomatitis virus glycoproteins (VSVGs), and the influenza virus WSN strain envelope proteins against ultracentrifugation. Lentiviral genomic and functional particles were more stable than the corresponding retroviral particles against ultracentrifugation when pseudotyped with VSVGs. However, both retroviral and lentiviral particles were unstable when pseudotyped with the influenza virus WSN strain envelope proteins. Therefore, the stabilities of pseudotyped retroviral and lentiviral vectors against ultracentrifugation process are a function of not only the type of envelope proteins, but also the type of viral internal core (MLV or HIV-1 core). In addition, the fraction of functional viral particles among genomic viral particles greatly varied at times during packaging, depending on the type of envelope proteins used for pseudotyping and the viral internal core.

  1. Foscarnet, zidovudine and dolutegravir combination efficacy and tolerability for late stage HIV salvage therapy: A case-series experience.

    PubMed

    Delory, Tristan; Papot, Emmanuelle; Rioux, Christophe; Charpentier, Charlotte; Auge-Courtoi, Claire; Michard, Florence; Peytavin, Gilles; Descamps, Diane; Matheron, Sophie; Yazdanpanah, Yazdan

    2016-07-01

    Salvage therapy including foscarnet (PFA), zidovudine (ZDV) and an optimized background ART (OBT) has been shown to be effective in patients with advanced HIV infection, and no therapeutic options. Dolutegravir (DTG) may offer a more active combination. Objective was to describe efficacy and tolerability of PFA-ZDV-DTG containing regimen. In our cohort, we identified patients who: (i) had plasma HIV-1 RNA load (pVL) >50 c/ml (>100 for HIV-2) on combination ART (cART); (ii) had at least 1 PI/r, 1 NRTI, 1 NNRTI (for HIV-1), and at least 1 raltegravir resistance mutations; (iii) were naive to DTG; and (iv) initiated on a PFA-ZDV-DTG containing-regimen with 48 weeks (W48) of follow-up. Out of 5 patients, 2 were infected with HIV-2. At PFA-ZDV-DTG initiation, CD4 cell count was (/mm(3) ) of 64, 40, 10, in HIV-1, and 37, 199, in HIV-2 infected patients; and pVL (log10 c/ml) of 4.8, 5.1, 4.4, in HIV-1, and 3.6, 4.2, in HIV-2 infected patients, respectively. Median OBT genotypic sensitivity score was 1.5 [1-2]. PFA was discontinued in one patient, due to an acute renal failure. At W48, one HIV-1 infected patient had a pVL <50 c/ml and two <200 c/ml; the two HIV-2 infected patients had pVL >100 c/ml. No lack of treatment adherence was observed. In treatment experienced HIV-infected patients, failing cART and without other therapeutic options, a PFA-ZDV-DTG combination therapy could be effective. Renal adverse events should be monitored.

  2. Nanoassemblies containing a fluorouracil/zidovudine glyceryl prodrug with phospholipase A2-triggered drug release for cancer treatment.

    PubMed

    Jin, Yiguang; Yang, Fang; Du, Lina

    2013-12-01

    Secretory phospholipase A2 (sPLA2), which is overexpressed in many tumors, cleaves ester bonds at the sn-2 position of phospholipids. A PLA2-sensitive amphiphilic prodrug, 1-O-octadecyl-2-(5-fluorouracil)-N-acetyl-3-zidovudine-phosphorylglycerol (OFZG), was synthesized and used to prepare nanoassemblies through the injection of a mixture of OFZG/cholesterol/Tween 80 (2:1:0.1, mol:mol:mol) into water. Cholesterol and Tween 80 was incorporated into the OFZG monolayers at the air/water interface to yield nanoassemblies. The resulting nanoassemblies exhibited a narrow size distribution with a mean size of 77.8nm and were stable due to their high surface charges. The in vitro experiments showed that PLA2 degraded OFZG. The nanoassemblies exhibited higher anticancer activity than the parent drug 5-fluorouracil (5-FU) in COLO205, HT-28, and HCT-116 cells. The intravenous (i.v.) administration of the nanoassemblies into mice resulted in the rapid elimination of OFZG from the circulation and its distribution mainly in the liver, lung, spleen, and kidney. After their injection into tumor-bearing mice, the nanoassemblies exhibited anticancer efficiency comparable to that of 5-FU, even though the nanoassemblies contained concentrations of only 1/10 of the molar amount of 5-FU. The lessons learned from the study and methods for the design of PLA2-sensitive amphiphilic prodrugs are also discussed. Enzyme-sensitive amphiphilic combinatorial prodrugs and prodrug-loaded nanoassemblies may represent a new strategy for anticancer drug design. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Effect of HIV-1 infection and sex on the cellular pharmacology of the antiretroviral drugs zidovudine and lamivudine.

    PubMed

    Rower, Joseph E; Meditz, Amie; Gardner, Edward M; Lichtenstein, Kenneth; Predhomme, Julie; Bushman, Lane R; Klein, Brandon; Zheng, Jia-Hua; Mawhinney, Samantha; Anderson, Peter L

    2012-06-01

    The cellular pharmacology of zidovudine (ZDV) and lamivudine (3TC) in vivo is not completely understood. This prospective longitudinal study investigated the relationship between HIV-1 serostatus, sex, race, and time on therapy with intracellular and plasma ZDV and 3TC concentrations. Of 20 HIV-seronegative and 23 HIV-seropositive volunteers enrolled, 16 (8 women) and 21 (5 women) completed all 12 study days, respectively. Volunteers began ZDV-3TC therapy (plus a third active drug in HIV-seropositive volunteers), and steady-state concentrations (C(ss)) were determined after days 1, 3, 7, and 12. A repeated-measures mixed model was utilized. HIV-seronegative status was associated with 22% (95% confidence interval [CI], 0%, 50%) and 37% (15%, 67%) higher C(ss) estimates compared to those of HIV-seropositive individuals for intracellular ZDV-TP and 3TC-TP levels, respectively. African-Americans had 36% (8%, 72%) higher ZDV-TP estimates than non-African-Americans. Sex was not associated with ZDV-TP or 3TC-TP (P > 0.19). Women had 36% (4%, 78%) higher plasma ZDV, but the effect was lessened when normalized by lean body weight (5% [-19%, 38%]; P = 0.68). Plasma 3TC was 19% (0%, 41%) higher in HIV-seropositive volunteers and 22% (0%, 48%) higher in African American volunteers, but these effects were not significant when corrected for creatinine clearance (7% [-9%, 20%] and -5% [-26%, 12%] for HIV serostatus and race, respectively; P > 0.35). These results suggest that HIV-seropositive status decreases and African American race elevates the cellular triphosphates of ZDV and 3TC. This information extends knowledge of ZDV and 3TC cellular pharmacology in vivo and provides new leads for future cellular pharmacology studies aimed at optimizing HIV prevention/treatment with these agents.

  4. Lopinavir/ritonavir plus lamivudine and abacavir or zidovudine dose ratios for paediatric fixed-dose combinations.

    PubMed

    Bouazza, Naïm; Foissac, Frantz; Fauchet, Floris; Burger, David; Kiechel, Jean-René; Treluyer, Jean-Marc; Capparelli, Edmund V; Lallemant, Marc; Urien, Saïk

    2015-01-01

    Lopinavir/ritonavir (LPV/r) is available in a liquid formulation that is far from ideal for treatment of children in resource-poor settings. Flexible, low-cost, solid, oral fixed-dose combinations (FDC) of LPV/r with nucleoside reverse transcriptase inhibitors (LPV/r/abacavir [ABC]/lamivudine [3TC] and LPV/r/zidovudine [ZDV]/3TC) are needed to improve both management and adherence of children. This work aimed to develop appropriate drug ratios and dosing for each FDC. Data from 25 combined datasets included therapeutic drug monitoring and clinical studies from IMPAACT and PENTA. Population pharmacokinetic analyses were performed using Monolix. Monte-Carlo simulations of WHO and FDA dosing recommendations were performed to assess their ability to provide optimal exposure in children weighing 4 to 25 kg based on consensus plasma targets. The LPV/r:3TC:ZDV(ABC) dose ratios were 2.67:1:2(2), respectively. Using WHO dosage, LPV efficacy target was reached in all weight bands. Given the recommended drug ratios, the dosage for the 4-5.9 kg weight band (LPV/ZDV: 120/90 mg twice daily [bid]) showed more than 20% of subjects had ZDV levels at high risk of neutropenia. Reducing the LPV/ZDV dose to 80/60 mg bid decreased frequency of high ZDV concentrations but retained the LPV efficacy criteria. This defined a flexible and simple FDC containing 40 mg LPV, 10 mg ritonavir, 15 mg 3TC and 30 mg ABC or ZDV. According to the weight bands defined by WHO, 4-5.9 kg, 6-9.9 kg, 10-13.9 kg, 14-19.9 kg, 20-24.9 kg, therapeutic doses would be 2, 3, 4, 5 or 6 individual units administered by oral route bid.

  5. Simultaneous determination of HIV-protease inhibitors lamivudine and zidovudine in pharmaceutical formulations by micellar electrokinetic chromatography.

    PubMed

    Sekar, R; Azhaguvel, S

    2005-09-15

    A micellar electrokinetic chromatographic (MEKC) method for the simultaneous separation and determination of lamivudine (LMV) and zidovudine (ZDV) in pharmaceutical formulation has been developed. Factors that affect the separation, such as buffer pH, surfactant concentration (sodium dodecyl sulfate, SDS), organic solvents and applied voltage were optimized. Buffer consisting of 12.5 mM sodium tetraborate decahydrate and 15 mM boric acid adjusted at pH 10.8, containing 90 mM SDS and 5% (v/v) acetonitrile (ACN) was found to be suitable for the separation of the drugs. p-Aminobenzoic acid (PABA) was used as internal standard (I.S.). Detection of analytes and I.S. was performed at a wavelength of 210 nm. It was observed that both the drugs and I.S. were migrated within 20 min at the applied voltage of +10 kV. Validation of the method was performed in terms of linearity, accuracy, precision, limit of detection (LOD) and quantification (LOQ). An excellent linearity was obtained in the concentration range 10-80 microg/ml for LMV and 10-100 microg/ml for ZDV. The detection limits for LMV and ZDV were found to be 2.5 and 2.0 microg/ml, respectively. The optimized method was applied to the simultaneous determination of LMV and ZDV in pharmaceutical formulation and human plasma (spiked) samples. Recovery of both the drugs in tablet dosage form and spiked drugs in plasma were > or =99.72% (relative standard deviation (R.S.D.)< or =1.84%) and > or =80.4% (R.S.D.< or =5.4%), respectively. In the electropherogram no interfering peaks were observed in the region of analytes and I.S. due to inactive ingredients in the tablets and matrices in plasma.

  6. Large-scale Clinical-grade Retroviral Vector Production in a Fixed-Bed Bioreactor

    PubMed Central

    Wang, Xiuyan; Olszewska, Malgorzata; Qu, Jinrong; Wasielewska, Teresa; Bartido, Shirley; Hermetet, Gregory; Sadelain, Michel

    2015-01-01

    The successful genetic engineering of patient T cells with γ-retroviral vectors expressing chimeric antigen receptors or T-cell receptors for phase II clinical trials and beyond requires the large-scale manufacture of high-titer vector stocks. The production of retroviral vectors from stable packaging cell lines using roller bottles or 10- to 40-layer cell factories is limited by a narrow harvest window, labor intensity, open-system operations, and the requirement for significant incubator space. To circumvent these shortcomings, we optimized the production of vector stocks in a disposable fixed-bed bioreactor using good manufacturing practice–grade packaging cell lines. High-titer vector stocks were harvested over 10 days, representing a much broader harvest window than the 3-day harvest afforded by cell factories. For PG13 and 293Vec packaging cells, the average vector titer and the vector stocks’ yield in the bioreactor were higher by 3.2- to 7.3-fold, and 5.6- to 13.1-fold, respectively, than those obtained in cell factories. The vector production was 10.4 and 18.6 times more efficient than in cell factories for PG13 and 293Vec cells, respectively. Furthermore, the vectors produced from the fixed-bed bioreactors passed the release test assays for clinical applications. Therefore, a single vector lot derived from 293Vec is suitable to transduce up to 500 patients cell doses in the context of large clinical trials using chimeric antigen receptors or T-cell receptors. These findings demonstrate for the first time that a robust fixed-bed bioreactor process can be used to produce γ-retroviral vector stocks scalable up to the commercialization phase. PMID:25751502

  7. Large-scale clinical-grade retroviral vector production in a fixed-bed bioreactor.

    PubMed

    Wang, Xiuyan; Olszewska, Malgorzata; Qu, Jinrong; Wasielewska, Teresa; Bartido, Shirley; Hermetet, Gregory; Sadelain, Michel; Rivière, Isabelle

    2015-04-01

    The successful genetic engineering of patient T cells with γ-retroviral vectors expressing chimeric antigen receptors or T-cell receptors for phase II clinical trials and beyond requires the large-scale manufacture of high-titer vector stocks. The production of retroviral vectors from stable packaging cell lines using roller bottles or 10- to 40-layer cell factories is limited by a narrow harvest window, labor intensity, open-system operations, and the requirement for significant incubator space. To circumvent these shortcomings, we optimized the production of vector stocks in a disposable fixed-bed bioreactor using good manufacturing practice-grade packaging cell lines. High-titer vector stocks were harvested over 10 days, representing a much broader harvest window than the 3-day harvest afforded by cell factories. For PG13 and 293Vec packaging cells, the average vector titer and the vector stocks' yield in the bioreactor were higher by 3.2- to 7.3-fold, and 5.6- to 13.1-fold, respectively, than those obtained in cell factories. The vector production was 10.4 and 18.6 times more efficient than in cell factories for PG13 and 293Vec cells, respectively. Furthermore, the vectors produced from the fixed-bed bioreactors passed the release test assays for clinical applications. Therefore, a single vector lot derived from 293Vec is suitable to transduce up to 500 patients cell doses in the context of large clinical trials using chimeric antigen receptors or T-cell receptors. These findings demonstrate for the first time that a robust fixed-bed bioreactor process can be used to produce γ-retroviral vector stocks scalable up to the commercialization phase.

  8. Green fluorescent protein retroviral vectors: low titer and high recombination frequency suggest a selective disadvantage.

    PubMed

    Hanazono, Y; Yu, J M; Dunbar, C E; Emmons, R V

    1997-07-20

    Green fluorescent protein (GFP) has been used as a reporter molecule for gene expression because it fluoresces green after blue-light excitation. Inclusion of this gene in a vector could allow rapid, nontoxic selection of successfully transduced cells. However, many attempts by our laboratory to isolate stable retroviral producer cell clones secreting biologically active vectors containing either the highly fluorescent S65T-GFP mutant or humanized GFP have failed. Vector plasmids containing various forms of GFP and the neomycin resistance gene were transfected into three different packaging cell lines and fluorescence was observed for several days, but stable clones selected with G418 no longer fluoresced. Using confocal microscopy, the brightest cells were observed to contract and die within a matter of days. RNA slot-blot analysis of retroviral producer supernatants showed no viral production from the GFP plasmid-transfected clones, although all clones derived after transfection with an identical retroviral construct not containing GFP produced virus. Genomic Southern analysis of the GFP-transduced clones showed a much higher probability of rearrangement of the priviral sequences than in the control non-GFP clones. Overall, 18/34 S65T-GFP clones and 17/33 humanized-GFP clones had rearrangements, whereas 2/15 control non-GFP clones had rearrangements. Hence, producer cells expressing high levels of these GFP genes seem to be selected against, with stable clones undergoing major rearrangements or other mutations that both abrogate GFP expression and prevent vector production. These observations indicate that GFP may not be an appropriate reporter gene for gene transfer applications in our vector/packaging system.

  9. Retroviral vectors containing Tet-controlled bidirectional transcription units for simultaneous regulation of two gene activities

    PubMed Central

    Loew, Rainer; Vigna, Elisa; Lindemann, Dirk; Naldini, Luigi; Bujard, Herman

    2006-01-01

    In this study retroviral self-inactivating (SIN)-vectors were constructed, that allow simultaneous regulation of two genes by integration of bidirectional Tet controlled transcription units. Marker genes (luciferase and eGFP) were expressed under the control of various bidirectional promoters Ptetbis, in order to determine (i) the fraction of HtTA-1 cells exhibiting tight doxycycline (Dox) dependent control; (ii) possible effects of the vector backbone on the regulation of gene transcription; (iii) the possibility for crosstalk between different minimal promoters within Ptetbi. When HtTA-1 cells, constitutively expressing the Tet-Transactivator (tTA), were transduced by S2f-lMCg retroviral vector, a high percentage (40) of the cell population displayed tight regulation (5000 fold) of Ptetbi activity over a wide range of Dox concentrations. As a result of our comparative study on the activity of virus derived minimal promoters (from MMTV, HIV and CMV), a clear hierarchy of activity as well as a different sensitivity to external influences among the various promoters studied was observed. Furthermore, our results strongly support the idea, that viral elements such as part of the MuLV pol/env region significantly affect the regulation capacity of an integrate. Taking into account our observations as outlined above, we succeeded in generating significantly optimized Tet regulated retroviral vectors. The application of such a one-step transfer system for Ptet controlled genes would be of particular relevance to applications where cellular systems do not allow prolonged selection procedures as it is the case with primary cells considered for ex vivo gene therapy. PMID:19565004

  10. Feasibility of retroviral vector-mediated in utero gene transfer to the fetal rabbit.

    PubMed

    Moreno, Rafael; Rosal, Marta; Cabero, Lluis; Gratacós, Eduard; Aran, Josep M

    2005-01-01

    Successful treatment or prevention of severe hereditary diseases could conceivably be achieved by genetic intervention early in development. Viral vector-mediated fetal gene transfer is proving a valuable tool to test the above concept in relevant animal models. Although the pregnant rabbit is a well-recognized model for fetal therapy, few preclinical assays have used it to validate fetal gene transfer approaches. In this preliminary study we assessed for the first time the feasibility of retroviral vector-mediated in utero gene transfer in the fetal rabbit. Different amounts of the vesicular stomatitis virus G pseudotyped MFG(nls)LacZ retroviral vector, expressing a nuclear-localized beta-galactosidase reporter protein were injected intraperitoneally and -hepatically into 20- to 22-day-old fetuses. At 8-9 days post-treatment, the pups were sacrificed and the tissues harvested for analysis. Evidence of gene transfer was obtained by PCR amplification of proviral sequences within genomic DNA isolated from the treated samples. Transgenic beta-galactosidase expression was assessed by X-gal histochemical staining. By intraperitoneal injection 43% of the viable fetuses treated (3/7) showed evidence of successful LacZ gene transfer and low-level beta-galactosidase expression into liver and heart, whereas by intrahepatic injection roughly 38% (3/8) of the livers were positive for LacZ gene transfer and expression. The success rate for the viable fetuses rose to 67% positive livers (4/6) when a near double amount of recombinant virus was injected using a 10-fold concentrated virus stock. In terms of short-term safety, fetal and maternal survival rates approached 80% of treated fetuses, and 100% of treated does. The pregnant rabbit is a useful and reliable model allowing the design of further studies to optimize the conditions for effective, safer, and persistent retroviral vector-mediated fetal gene transfer. Copyright (c) 2005 S. Karger AG, Basel.

  11. Bone marrow extracellular matrix molecules improve gene transfer into human hematopoietic cells via retroviral vectors.

    PubMed

    Moritz, T; Patel, V P; Williams, D A

    1994-04-01

    Direct contact between hematopoietic cells and viral packaging cell lines or other sources of stroma has been shown to increase the efficiency of retroviral-mediated gene transfer into these target cells compared with infection with viral supernatant. We have investigated the role of defined bone marrow extracellular matrix molecules (ECM) in this phenomenon. Here we report that infection of cells adhering to the carboxy-terminal 30/35-kD fragment of the fibronectin molecule (30/35 FN), which contains the alternatively spliced CS-1 cell adhesion domain, significantly increases gene transfer into hematopoietic cells. Two retroviral vectors differing in recombinant viral titer were used. Gene transfer into committed progenitor cells and long-term culture-initiating cells, an in vitro assay for human stem cells, was significantly increased when the cells were infected while adherent to 30/35 FN-coated plates compared with cells infected on BSA-coated control plates or plates coated with other bone marrow ECM molecules. Although gene transfer into committed progenitor cells and to a lesser degree into long-term culture-initiating cells was increased on intact fibronectin as well, increased gene transfer efficiency into hematopoietic cells on 30/35 FN was dependent on CS-1 sequence since infection on a similar FN fragment lacking CS-1 (42 FN) was suboptimal. 30/35 FN has previously been shown by our laboratory and other investigators to mediate adhesion of primitive murine and human hematopoietic stem cells to the hematopoietic microenvironment. Additional studies showed that neither soluble 30/35 FN nor nonspecific binding of hematopoietic cells to poly-L-lysine-coated plates had any appreciable effect on the infection efficiency of these cells. Our findings indicate that hematopoietic stem cell adhesion to specific ECM molecules alters retroviral infection efficiency. These findings should aid in the design of gene transfer protocols using hematopoietic progenitor and

  12. Epidemiologic studies of adverse effects of anti-retroviral drugs: how well is statistical power reported.

    PubMed

    Halpern, Scott D; Barton, Todd D; Gross, Robert; Hennessy, Sean; Berlin, Jesse A; Strom, Brian L

    2005-03-01

    To determine whether there is a difference in average statistical power between pharmacoepidemiologic studies of anti-retroviral adverse drug effects (ADEs) sponsored by for-profit versus non-profit organizations. We studied all published pharmacoepidemiologic studies of ADEs associated with the 15 anti-retroviral drugs approved through the end of 1999. A priori, the primary outcome was the power of each study to detect a clinically important difference in the risk for an adverse effect among patients exposed to the study drug(s). We could not evaluate this outcome because of the infrequent reporting of power calculations. We instead report the distribution of studies across a 5-tiered measure of adequacy of reporting of statistical power, as well as the sponsorship of these studies. Of 48 studies meeting our inclusion criteria, only 1 (2%) reported either a completed, a priori power calculation or sufficient details for readers to calculate the power to detect a pre-defined, clinically important effect. Thirty-five studies (73%) reported the minimum information required for sophisticated readers to determine the power to detect an event rate of interest to them; 6 additional studies (13%) reported confidence intervals around at least one summary effect measure and 6 (13%) provided no indication of power or uncertainty. Of the 41 studies for which sponsorship was determined, only 3 (7%) were sponsored by for-profit organizations. The poor reporting of statistical power in this sample suggests a need for guidelines to improve the reporting of pharmacoepidemiologic studies of ADEs. Future research is needed to determine whether the observed paucity of industry-sponsored observational studies of anti-retroviral ADEs extends to other clinical areas, and if so, to identify the causes of this phenomenon. Copyright 2004 John Wiley & Sons, Ltd.

  13. Electrolyte imbalance and sleep problems during anti-retroviral therapy: an under-recognized problem.

    PubMed

    Manzar, Md Dilshad; Sony, Peter; Salahuddin, Mohammed; Kumalo, Abera; Geneto, Mathewos; Pandi-Perumal, Seithikurippu R; Moscovitch, Adam; BaHammam, Ahmed S

    2017-01-01

    Human immunodeficiency virus (HIV) infection, and the anti-retroviral therapy (ART) associated complications necessitate that the medical care system keeps evolving for proper management of this group of patients. Electrolyte imbalance and sleep problems are common in patients on ART. Both of these conditions are associated with increased morbidity (such as acute kidney injury, chronic kidney disease, low CD4 count, non-adherence and depression) and mortality. Therefore, screening for both sleep problems and electrolytes imbalance may help to decrease the risk of complications in patients on ART.

  14. Electrolyte imbalance and sleep problems during anti-retroviral therapy: an under-recognized problem

    PubMed Central

    Manzar, Md Dilshad; Sony, Peter; Salahuddin, Mohammed; Kumalo, Abera; Geneto, Mathewos; Pandi-Perumal, Seithikurippu R; Moscovitch, Adam; BaHammam, Ahmed S

    2017-01-01

    Human immunodeficiency virus (HIV) infection, and the anti-retroviral therapy (ART) associated complications necessitate that the medical care system keeps evolving for proper management of this group of patients. Electrolyte imbalance and sleep problems are common in patients on ART. Both of these conditions are associated with increased morbidity (such as acute kidney injury, chronic kidney disease, low CD4 count, non-adherence and depression) and mortality. Therefore, screening for both sleep problems and electrolytes imbalance may help to decrease the risk of complications in patients on ART. PMID:28966741

  15. Detecting Statistically Significant Common Insertion Sites in Retroviral Insertional Mutagenesis Screens

    PubMed Central

    de Ridder, Jeroen; Uren, Anthony; Kool, Jaap; Reinders, Marcel; Wessels, Lodewyk

    2006-01-01

    Retroviral insertional mutagenesis screens, which identify genes involved in tumor development in mice, have yielded a substantial number of retroviral integration sites, and this number is expected to grow substantially due to the introduction of high-throughput screening techniques. The data of various retroviral insertional mutagenesis screens are compiled in the publicly available Retroviral Tagged Cancer Gene Database (RTCGD). Integrally analyzing these screens for the presence of common insertion sites (CISs, i.e., regions in the genome that have been hit by viral insertions in multiple independent tumors significantly more than expected by chance) requires an approach that corrects for the increased probability of finding false CISs as the amount of available data increases. Moreover, significance estimates of CISs should be established taking into account both the noise, arising from the random nature of the insertion process, as well as the bias, stemming from preferential insertion sites present in the genome and the data retrieval methodology. We introduce a framework, the kernel convolution (KC) framework, to find CISs in a noisy and biased environment using a predefined significance level while controlling the family-wise error (FWE) (the probability of detecting false CISs). Where previous methods use one, two, or three predetermined fixed scales, our method is capable of operating at any biologically relevant scale. This creates the possibility to analyze the CISs in a scale space by varying the width of the CISs, providing new insights in the behavior of CISs across multiple scales. Our method also features the possibility of including models for background bias. Using simulated data, we evaluate the KC framework using three kernel functions, the Gaussian, triangular, and rectangular kernel function. We applied the Gaussian KC to the data from the combined set of screens in the RTCGD and found that 53% of the CISs do not reach the significance

  16. Anti-retroviral drugs compliance in intravenous and non intravenous drug abusers.

    PubMed

    Daud, Muhammad Yousuf; Qazi, Rizwan Aziz; Bashir, Naila

    2014-01-01

    Intravenous drug abuse is often associated with poor adherence to anti-retroviral drugs in HIV/AIDS. Very few studies in Pakistan have determined implications of intravenous drug abuse on anti-retroviral drug compliance in HIV/AIDS patients. The objectives of the study were to assess and compare the adherence to anti-retroviral drugs in intravenous drug users (IDUs) and non-intravenous drug users (NIDUs) and to determine various factors influencing the adherence to anti-retroviral (ARV) drugs in HIV positive IDUs in HIV treatment centre Pakistan Institute of Medical Sciences (PIMS), Islamabad. This descriptive observational study was carried out at HIV/AIDS treatment and care centre PIMS, Islamabad. A total of 162 HIV positive male (81 IDU and 81 NIDU) were enrolled in this study. They were followed over a period of five years from 2008-2012. ARV drug compliance and anti-tuberculosis treatment (ATT) outcome in IDUs and NIDUs were assessed using standard outcome parameters. Among IDUs Hepatitis C was positive in 63 (77.77%) cases and negative in 18 (22.22%) cases. In NIDUs hepatitis C was positive in 5 (6.17%) and negative in 76 (93.82%) (p=0.000). In IDUs Pulmonary tuberculosis was present in 61 (75.30%) patients and in NIDUs it was present in 52 (64.19%) (p=0.171). Regarding ATT outcome, amongst IDUs 41 (50.61%) lost to follow up, 16 (19.75%) were compliant to treatment and 4 (4.93%) were transferred out. In NIDUs, 2 (2.46%) patients were lost to follow-up, 38 (46.91%) remained compliant to treatment and 6 (7.40%) were transferred out (p=0.000). Regarding end status of ARVs, in IDUs, 48 (59.25%) were lost to follow-up, 1 (1.23%) was defaulter, 16 (19.75%) were compliant to treatment, 8 (9.87%) were transferred out and 8 (9.87%) expired. In NIDUs, 73 (90.12%) were compliant to treatment, 5 (6.17%) expired, 2 (2.46%) were lost to follow-up. Due to various socioeconomic and clinical factors, compliance to ARVs in IDUs is poorer as compared to NIDUs. The factors

  17. Introduction of new genetic material into human myeloid leukemic blast stem cells by retroviral infection

    SciTech Connect

    Smith, L.J.; Benchimol, S.

    1988-02-01

    An amphotropic retroviral vector containing the bacterial neomycin phosphotransferase gene (neo) was used to infect blast cells from patients with acute myeloblastic leukemia. The infected cells acquired a G418-resistant phenotype that was stable as measured in a clonogenic assay and in long-term suspension culture. Thus, gene transfer into stem cells was accomplished by this procedure. This approach for manipulating gene expression in blast stem cells provides a means to assess the roles of a variety of genes in self-renewal, differentiation, and leukemogenesis.

  18. Inducible expression of p21WAF-1/CIP-1/SDI-1 from a promoter conversion retroviral vector.

    PubMed

    Mrochen, S; Klein, D; Nikol, S; Smith, J R; Salmons, B; Günzburg, W H

    1997-01-01

    Constitutive, high-level expression of the potentially therapeutic WAF-1/CIP-1/SDI-1 gene is incompatible with cell growth. A promoter conversion retroviral vector carrying the WAF-1/CIP-1/SDI-1 gene under the transcriptional control of the glucocorticoid inducible promoter of mouse mammary tumor virus was used to infect human bladder carcinoma or feline kidney cells. Reduced cell growth due to a greater proportion of cells being in the G0/G1 phase of the cell cycle was observed when WAF-1/CIP-1/SDI-1 expression was activated by addition of glucocorticoid hormone. This system demonstrates the potential long-term therapeutic use of WAF-1/CIP-1/SDI-1 delivered by retroviral vectors for inhibiting the growth of rapidly proliferating cells. Moreover, the conditional expression of genes such as WAF-1/CIP-1/SDI-1 from such retroviral vectors may facilitate analysis of their function.

  19. The nucleoside reverse transcriptase inhibitors didanosine, lamivudine, stavudine and zidovudine show little effect on the virulence of Candida albicans in vitro.

    PubMed

    Ahmadou Ahidjo, Bintou; Veale, Rob; Dusé, Adriano G; Becker, Piet; Marais, Else

    2008-08-01

    Nucleoside reverse transcriptase inhibitors (NRTIs) are used in the treatment of human immunodeficiency virus (HIV). Since the analogue 5-fluorouracil increases Candida albicans virulence in vitro, and zidovudine therapy is associated with enhanced C. albicans adherence and biofilm formation, we investigated the effects of commonly used NRTIs on the virulence of C. albicans isolated from 21 antiretroviral-naïve HIV/AIDS patients. The isolates were exposed to didanosine, lamivudine, stavudine and zidovudine at their expected patient serum peak levels and at one-half and two times these levels for 24h and 72 h. Assays assessing changes in adherence, proliferation, biofilm formation and antifungal susceptibility were performed. No differences in these virulence characteristics of isolates exposed to NRTIs were noted in most cases. However, at 24h and 72 h a significant increase in the rate of proliferation was observed in response to two-fold the peak concentration of lamivudine. The results suggest a limited effect of NRTIs on C. albicans virulence.

  20. Formulation and optimization of coated PLGA - Zidovudine nanoparticles using factorial design and in vitro in vivo evaluations to determine brain targeting efficiency.

    PubMed

    Peter Christoper, G V; Vijaya Raghavan, C; Siddharth, K; Siva Selva Kumar, M; Hari Prasad, R

    2014-04-01

    In the current study zidovudine loaded PLGA nanoparticles were prepared, coated and further investigated for its effectiveness in brain targeting. IR and DSC studies were performed to determine the interaction between excipients used and to find out the nature of drug in the formulation. Formulations were prepared by adopting 2(3) factorial designs to evaluate the effects of process and formulation variables. The prepared formulations were subjected for in vitro and in vivo evaluations. In vitro evaluations showed particle size below 100 nm, entrapment efficiency of formulations ranges of 28-57%, process yield of 60-76% was achieved and drug release for the formulations were in the range of 50-85%. The drug release from the formulations was found to follow Higuchi release pattern, n-value obtained after Korsemeyer plot was in the range of 0.56-0.78. In vivo evaluations were performed in mice after intraperitoneal administration of zidovudine drug solution, uncoated and coated formulation. Formulation when coated with Tween 80 achieved a higher concentration in the brain than that of the drug in solution and of the uncoated formulation. Stability studies indicated that there was no degradation of the drug in the formulation after 90 days of preparation when stored in refrigerated condition.

  1. [Clinical experience with zidovudine in patients with acquired immunodeficiency syndrome. Analysis of 117 cases. Grupo Andaluz para el Estudio de las Enfermedades Infecciosas].

    PubMed

    Biedma, D; Bascuñana, A; Viciana, P; Causse, M; Torres Tortosa, M; Lozano de León, F; Pujol, E; Pachón, J

    1992-09-01

    In order to assess the efficacy and the toxicity of zidovudine in AIDS patients, we have studied, prospectively, 117 patients that were treated with this drug, in several andalusian hospitals between January 1988 and June 1990. Initial dose of the drug was 200 mg every 4 hours. Mean survival was 100% at 6 months and 66.5% at 23 months. Survival at 19 months was higher in ADVP (77%) than in non-ADVP (48%). A positive influence on weight. Karnofsky index and number of opportunistic infections during the six first months of treatment was recorded, benefit that was lost progressively from that moment onwards. Main adverse effects were hematological, 10.1% of the patients requiring transfusions due to hemoglobin lower than 6.5 gr%. The more frequent cause to stop therapy was severe neutropenia (less than 500 neutrophils per mm). We consider that the beneficial effect of zidovudine is only transient, diminishing gradually when the treatment is prolonged. At present doses adverse effects are moderate not being present in most of the patients.

  2. Formulation and optimization of coated PLGA – Zidovudine nanoparticles using factorial design and in vitro in vivo evaluations to determine brain targeting efficiency

    PubMed Central

    Peter Christoper, G.V.; Vijaya Raghavan, C.; Siddharth, K.; Siva Selva Kumar, M.; Hari Prasad, R.

    2013-01-01

    In the current study zidovudine loaded PLGA nanoparticles were prepared, coated and further investigated for its effectiveness in brain targeting. IR and DSC studies were performed to determine the interaction between excipients used and to find out the nature of drug in the formulation. Formulations were prepared by adopting 23 factorial designs to evaluate the effects of process and formulation variables. The prepared formulations were subjected for in vitro and in vivo evaluations. In vitro evaluations showed particle size below 100 nm, entrapment efficiency of formulations ranges of 28–57%, process yield of 60–76% was achieved and drug release for the formulations were in the range of 50–85%. The drug release from the formulations was found to follow Higuchi release pattern, n–value obtained after Korsemeyer plot was in the range of 0.56–0.78. In vivo evaluations were performed in mice after intraperitoneal administration of zidovudine drug solution, uncoated and coated formulation. Formulation when coated with Tween 80 achieved a higher concentration in the brain than that of the drug in solution and of the uncoated formulation. Stability studies indicated that there was no degradation of the drug in the formulation after 90 days of preparation when stored in refrigerated condition. PMID:24648825

  3. High-dose zidovudine plus valganciclovir for Kaposi sarcoma herpesvirus-associated multicentric Castleman disease: a pilot study of virus-activated cytotoxic therapy

    PubMed Central

    Uldrick, Thomas S.; Polizzotto, Mark N.; Aleman, Karen; O'Mahony, Deirdre; Wyvill, Kathleen M.; Wang, Victoria; Marshall, Vickie; Pittaluga, Stefania; Steinberg, Seth M.; Tosato, Giovanna; Whitby, Denise; Little, Richard F.

    2011-01-01

    Kaposi sarcoma herpesvirus (KSHV)–associated multicentric Castleman disease (MCD) is a lymphoproliferative disorder most commonly observed in HIV-infected patients. It is characterized by KSHV-infected plasmablasts that frequently express lytic genes. Patients manifest inflammatory symptoms attributed to overproduction of KSHV viral IL-6, human IL-6, and human IL-6. There is no standard therapy and no established response criteria. We investigated an approach targeting 2 KSHV lytic genes, ORF36 and ORF21, the protein of which, respectively, phosphorylate ganciclovir and zidovudine to toxic moieties. In a pilot study, 14 HIV-infected patients with symptomatic KSHV-MCD received high-dose zidovudine (600 mg orally every 6 hours) and the oral prodrug, valganciclovir (900 mg orally every 12 hours). Responses were evaluated using new response criteria. A total of 86% of patients attained major clinical responses and 50% attained major biochemical responses. Median progression-free survival was 6 months. With 43 months of median follow-up, overall survival was 86% at 12 months and beyond. At the time of best response, the patients showed significant improvements in C-reactive protein, albumin, platelets, human IL-6, IL-10, and KSHV viral load. The most common toxicities were hematologic. These observations provide evidence that therapy designed to target cells with lytic KSHV replication has activity in KSHV-MCD. This trial was registered at www.clinicaltrials.gov as #NCT00099073. PMID:21487108

  4. Novel principles of gamma-retroviral insertional transcription activation in murine leukemia virus-induced end-stage tumors.

    PubMed

    Sokol, Martin; Wabl, Matthias; Ruiz, Irene Rius; Pedersen, Finn Skou

    2014-05-19

    Insertional mutagenesis screens of retrovirus-induced mouse tumors have proven valuable in human cancer research and for understanding adverse effects of retroviral-based gene therapies. In previous studies, the assignment of mouse genes to individual retroviral integration sites has been based on close proximity and expression patterns of annotated genes at target positions in the genome. We here employed next-generation RNA sequencing to map retroviral-mouse chimeric junctions genome-wide, and to identify local patterns of transcription activation in T-lymphomas induced by the murine leukemia gamma-retrovirus SL3-3. Moreover, to determine epigenetic integration preferences underlying long-range gene activation by retroviruses, the colocalization propensity with common epigenetic enhancer markers (H3K4Me1 and H3K27Ac) of 6,117 integrations derived from end-stage tumors of more than 2,000 mice was examined. We detected several novel mechanisms of retroviral insertional mutagenesis: bidirectional activation of mouse transcripts on opposite sides of a provirus including transcription of unannotated mouse sequence; sense/antisense-type activation of genes located on opposite DNA strands; tandem-type activation of distal genes that are positioned adjacently on the same DNA strand; activation of genes that are not the direct integration targets; combination-type insertional mutagenesis, in which enhancer activation, alternative chimeric splicing and retroviral promoter insertion are induced by a single retrovirus. We also show that irrespective of the distance to transcription start sites, the far majority of retroviruses in end-stage tumors colocalize with H3K4Me1 and H3K27Ac-enriched regions in murine lymphoid tissues. We expose novel retrovirus-induced host transcription activation patterns that reach beyond a single and nearest annotated gene target. Awareness of this previously undescribed layer of complexity may prove important for elucidation of adverse effects

  5. Truncation of TRIM5 in the Feliformia explains the absence of retroviral restriction in cells of the domestic cat.

    PubMed

    McEwan, William A; Schaller, Torsten; Ylinen, Laura M; Hosie, Margaret J; Towers, Greg J; Willett, Brian J

    2009-08-01

    TRIM5alpha mediates a potent retroviral restriction phenotype in diverse mammalian species. Here, we identify a TRIM5 transcript in cat cells with a truncated B30.2 capsid binding domain and ablated restrictive function which, remarkably, is conserved across the Feliformia. Cat TRIM5 displayed no restriction activity, but ectopic expression conferred a dominant negative effect against human TRIM5alpha. Our findings explain the absence of retroviral restriction in cat cells and suggest that disruption of the TRIM5 locus has arisen independently at least twice in the Carnivora, with implications concerning the evolution of the host and pathogen in this taxon.

  6. Truncation of TRIM5 in the Feliformia Explains the Absence of Retroviral Restriction in Cells of the Domestic Cat▿

    PubMed Central

    McEwan, William A.; Schaller, Torsten; Ylinen, Laura M.; Hosie, Margaret J.; Towers, Greg J.; Willett, Brian J.

    2009-01-01

    TRIM5α mediates a potent retroviral restriction phenotype in diverse mammalian species. Here, we identify a TRIM5 transcript in cat cells with a truncated B30.2 capsid binding domain and ablated restrictive function which, remarkably, is conserved across the Feliformia. Cat TRIM5 displayed no restriction activity, but ectopic expression conferred a dominant negative effect against human TRIM5α. Our findings explain the absence of retroviral restriction in cat cells and suggest that disruption of the TRIM5 locus has arisen independently at least twice in the Carnivora, with implications concerning the evolution of the host and pathogen in this taxon. PMID:19494015

  7. Consistent production of transgenic chickens using replication-deficient retroviral vectors and high-throughput screening procedures.

    PubMed

    Harvey, A J; Speksnijder, G; Baugh, L R; Morris, J A; Ivarie, R

    2002-02-01

    We have developed a novel method of DNA extraction combined with a high-throughput method of gene detection allowing thousands of potentially transgenic chicks to be screened quickly and reliably. By using this method and a replication-deficient retroviral vector based on avian leukosis virus (ALV), we have demonstrated germline transmission of three different transgenes. Several generations of chickens carrying intact transgenes were produced, validating the use of the ALV retroviral vectors for large-scale production of transgenic flocks. Fourth-generation chicks that were nontransgenic, hemizygous, or homozygous for the transgene were identified with the combined genetic screening methods.

  8. Detection of sequences homologous to human retroviral DNA in multiple sclerosis by gene amplification

    SciTech Connect

    Greenberg, S.J.; Ehrlich, G.D.; Abbott, M.A.; Hurwitz, B.J.; Waldmann, T.A.; Poiesz, B.J. )

    1989-04-01

    Twenty-one patients with multiple sclerosis, chronic progressive type, were examined for DNA sequences homologous to a human retrovirus. Genomic DNA from peripheral blood mononuclear cells was analyzed for the presence of homologous sequences to the human T-cell leukemia/lymphoma virus type I (HTLV-I) long terminal repeat, 3{prime} gag, pol, and env domains by the enzymatic in vitro gene amplification technique, polymerase chain reaction. Positive identification of homologous pol sequences was made in the amplified DNA from six of these patients (29%). Three of these six patients (14%) also tested positive for the env region, but not for the other regions tested. In contrast, none of the samples from 35 normal individuals studied was positive when amplified and tested with the same primers and probes. Comparison of patterns obtained from controls and from patients with adult T-cell leukemia or tropical spastic paraparesis suggests that the DNA sequences identified are exogenous to the human genome and may correspond to a human retroviral species. The data support the detection of a human retroviral agent in some patients with multiple sclerosis.

  9. Mechanism of Nucleic Acid Chaperone Function of Retroviral Nuceleocapsid (NC) Proteins

    NASA Astrophysics Data System (ADS)

    Rouzina, Ioulia; Vo, My-Nuong; Stewart, Kristen; Musier-Forsyth, Karin; Cruceanu, Margareta; Williams, Mark

    2006-03-01

    Recent studies have highlighted two main activities of HIV-1 NC protein contributing to its function as a universal nucleic acid chaperone. Firstly, it is the ability of NC to weakly destabilize all nucleic acid,(NA), secondary structures, thus resolving the kinetic traps for NA refolding, while leaving the annealed state stable. Secondly, it is the ability of NC to aggregate NA, facilitating the nucleation step of bi-molecular annealing by increasing the local NA concentration. In this work we use single molecule DNA stretching and gel-based annealing assays to characterize these two chaperone activities of NC by using various HIV-1 NC mutants and several other retroviral NC proteins. Our results suggest that two NC functions are associated with its zinc fingers and cationic residues, respectively. NC proteins from other retroviruses have similar activities, although expressed to a different degree. Thus, NA aggregating ability improves, and NA duplex destabilizing activity decreases in the sequence: MLV NC, HIV NC, RSV NC. In contrast, HTLV NC protein works very differently from other NC proteins, and similarly to typical single stranded NA binding proteins. These features of retroviral NCs co-evolved with the structure of their genomes.

  10. Biologically active mutants with deletions in the v-mos oncogene assayed with retroviral vectors.

    PubMed Central

    Bold, R J; Donoghue, D J

    1985-01-01

    We have constructed retroviral expression vectors by manipulation of the Moloney murine leukemia virus genome such that an exogenous DNA sequence may be inserted and subsequently expressed when introduced into mammalian cells. A series of N-terminal deletions of the v-mos oncogene was constructed and assayed for biological activity with these retroviral expression vectors. The results of the deletion analysis demonstrate that the region of p37mos coding region upstream of the third methionine codon is dispensable with respect to transformation. However, deletion mutants of v-mos which allow initiation of translation at the fourth methionine codon have lost the biological activity of the parental v-mos gene. Furthermore, experiments were also carried out to define the C-terminal limit of the active region of p37mos by the construction of premature termination mutants by the insertion of a termination oligonucleotide. Insertion of the oligonucleotide just 69 base pairs upstream from the wild-type termination site abolished the focus-forming ability of v-mos. Thus, we have shown the N-terminal limit of the active region of p37mos to be between the third and fourth methionines, while the C-terminal limit is within the last 23 amino acids of the protein. PMID:3018503

  11. Construction and characterization of a highly complex retroviral library for lineage analysis.

    PubMed Central

    Golden, J A; Fields-Berry, S C; Cepko, C L

    1995-01-01

    Replication-incompetent retroviral vectors encoding histochemical reporter genes have been used for studying lineal relationships in a variety of species. A crucial element in the interpretation of data generated by this method is the identification of sibling relationships, or clonal boundaries. The use of a library of viruses in which each member is unique can greatly facilitate this aspect of the analysis. A previously reported murine retroviral library containing about 80 members demonstrated the utility of the library approach. However, the relatively low number of tags in the murine library necessitated using low infection rates in order to give confidence in clonal assignments. To obviate the need for low infection rates, a far more complex library was created and characterized. The CHAPOL library was constructed such that each member encodes a histochemical reporter gene and has a DNA tag derived from a degenerate oligonucleotide pool synthesized to have a complexity of > 1 x 10(7). The library was tested after infection of cells in vitro or in vivo. The DNA tag from each histochemically labeled cell or clone of cells was recovered by PCR and sequenced for unambiguous identification. Three hundred and twenty tags have been identified after infection, and so far no tag has been seen to result from more than one independent infection. Thus, an equal distribution of inserts is suggested, and Monte Carlo analysis predicts a complexity of > 10(4) members. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7777573

  12. Retroviral-mediated transfer of the human glucocerebrosidase gene into cultured Gaucher bone marrow.

    PubMed Central

    Nolta, J A; Yu, X J; Bahner, I; Kohn, D B

    1992-01-01

    Gaucher disease, a lysosomal glycolipid storage disorder, results from the genetic deficiency of an acidic glucosidase, glucocerebrosidase (GC). The beneficial effects of allogeneic bone marrow transplantation (BMT) for Gaucher disease suggest that GC gene transduction and the transplantation of autologous hematopoietic stem cells (gene therapy) may similarly alleviate symptoms. We have constructed a retroviral vector, L-GC, produced by a clone of the amphotropic packaging cell line PA317, which transduces the normal human GC cDNA with high efficiency. Whole-marrow mononuclear cells and CD34-enriched cells from a 4-yr-old female with type 3 Gaucher disease were transduced by the L-GC vector and studied in long-term bone marrow culture (LTBMC). Prestimulation of marrow with IL-3 and IL-6, followed by co-cultivation with vector-producing fibroblasts, produced gene transfer into 40-45% of the hematopoietic progenitor cells. The levels of GC expression in progeny cells (primarily mature myelomonocytic) produced by the LTBMC were quantitatively analyzed by Northern blot, Western blot, and glucocerebrosidase enzyme assay. Normal levels of GC RNA, immunoreactive protein, and enzymatic activity were detected throughout the duration of culture. These studies demonstrate that retroviral vectors can efficiently transfer the GC gene into long-lived hematopoietic progenitor cells from the bone marrow of patients with Gaucher disease and express physiologically relevant levels of GC enzyme activity. Images PMID:1379609

  13. Epigenetic regulation of transcription and splicing of syncytins, fusogenic glycoproteins of retroviral origin

    PubMed Central

    Trejbalová, Kateřina; Blažková, Jana; Matoušková, Magda; Kučerová, Dana; Pecnová, Lubomíra; Vernerová, Zdenka; Heráček, Jiří; Hirsch, Ivan; Hejnar, Jiří

    2011-01-01

    Syncytin-1 and -2, human fusogenic glycoproteins encoded by the env genes of the endogenous retroviral loci ERVWE1 and ERVFRDE1, respectively, contribute to the differentiation of multinucleated syncytiotrophoblast in chorionic villi. In non-trophoblastic cells, however, the expression of syncytins has to be suppressed to avoid potential pathogenic effects. We studied the epigenetic suppression of ERVWE1 and ERVFRDE1 5′-long terminal repeats by DNA methylation and chromatin modifications. Immunoprecipitation of the provirus-associated chromatin revealed the H3K9 trimethylation at transcriptionally inactivated syncytins in HeLa cells. qRT-PCR analysis of non-spliced ERVWE1 and ERVFRDE1 mRNAs and respective env mRNAs detected efficient splicing of endogenously expressed RNAs in trophoblastic but not in non-placental cells. Pointing to the pathogenic potential of aberrantly expressed syncytin-1, we have found deregulation of transcription and splicing of the ERVWE1 in biopsies of testicular seminomas. Finally, ectopic expression experiments suggest the importance of proper chromatin context for the ERVWE1 splicing. Our results thus demonstrate that cell-specific retroviral splicing represents an additional epigenetic level controling the expression of endogenous retroviruses. PMID:21771862

  14. The impact of maternal anti-retroviral therapy on cytokine profile in the uninfected neonates.

    PubMed

    Kasahara, Taissa M; Hygino, Joana; Blanco, Bernardo; Xavier, Luciana; Araújo-Lima, Carlos Fernando; Guillermo, Landi V C; Bittencourt, Vera Carolina B; Guimarães, Vander; Andrade, Arnaldo F B; Bento, Cleonice A M

    2013-09-01

    The number of HIV-infected young women has been increasing since the beginning of the AIDS epidemic. The objective of the present study was to investigate the impact of anti-retroviral treatment (ART) of HIV-1-infected pregnant women (PW) on cytokine profile of uninfected neonates. Our results demonstrated that higher levels of IL-1β and TNF-α associated with lower IL-10 production were detected in the plasma obtained from neonates born from ART-treated PW. Furthermore, the production of TNF- α and IFN-γ was also significantly higher in polyclonally-activated T cells from those neonates. This elevated pro-inflammatory pattern detected by these activated-T cells was not associated to HIV-1 antigens sensitization. Finally, ART-exposed neonates showed to be born with lower weight, and it was inversely correlated with maternal peripheral TNF-a level. In summary, the data presented here suggest a significant disturbance in cytokine network of HIV-1-uninfected neonates exposed to potent anti-retroviral schemes during pregnancy.

  15. DNA minicircles clarify the specific role of DNA structure on retroviral integration.

    PubMed

    Pasi, Marco; Mornico, Damien; Volant, Stevenn; Juchet, Anna; Batisse, Julien; Bouchier, Christiane; Parissi, Vincent; Ruff, Marc; Lavery, Richard; Lavigne, Marc

    2016-09-19

    Chromatin regulates the selectivity of retroviral integration into the genome of infected cells. At the nucleosome level, both histones and DNA structure are involved in this regulation. We propose a strategy that allows to specifically study a single factor: the DNA distortion induced by the nucleosome. This strategy relies on mimicking this distortion using DNA minicircles (MCs) having a fixed rotational orientation of DNA curvature, coupled with atomic-resolution modeling. Contrasting MCs with linear DNA fragments having identical sequences enabled us to analyze the impact of DNA distortion on the efficiency and selectivity of integration. We observed a global enhancement of HIV-1 integration in MCs and an enrichment of integration sites in the outward-facing DNA major grooves. Both of these changes are favored by LEDGF/p75, revealing a new, histone-independent role of this integration cofactor. PFV integration is also enhanced in MCs, but is not associated with a periodic redistribution of integration sites, thus highlighting its distinct catalytic properties. MCs help to separate the roles of target DNA structure, histone modifications and integrase (IN) cofactors during retroviral integration and to reveal IN-specific regulation mechanisms.

  16. Strategies for the isolation and purification of retroviral vectors for gene therapy.

    PubMed

    Braas, G; Searle, P F; Slater, N K; Lyddiatt, A

    1996-01-01

    Viral gene therapy vectors promise new opportunities for treatment of hitherto debilitating and life threatening illnesses. To enable early and rapid clinical evaluation of the therapeutic potential of the technology, the initial objectives of process development have so far largely concerned vector assembly, product quality and safety, and manufacturing consistency appropriate to modest scales. The first of such vectors are under test in clinical trials approved through the regulatory CTX/IND route and thus conform to the standards specified for purity and contaminant removal. Process optimisation, scale-up and operability have been of secondary concern and the establishment of a scientific basis for the mechanistic development of future vector manufacturing processes has yet to be seriously addressed. This review considers the manufacturing demands of retroviral vectors and the candidate separation technologies which could facilitate preparation of clinical grade materials. Note is made that the practising community appears to place implicit confidence in the capability of conventional membranes and chromatographic supports developed for protein purification to perform adequately for large-scale purification of viruses. In particular, these are expected to deliver virus preparations to product standards currently required of therapeutic proteins. It is argued that the basis for this confidence may be ill-placed, since the physical and chemical characteristics of viral particles differ significantly from macromolecular proteins. The specific requirements for separation systems and materials for processing of retroviral vectors are considered, and specific routes to more efficient manufacturing processes are proposed.

  17. Identification and Characterization of Enhancer-Blocking Insulators to Reduce Retroviral Vector Genotoxicity

    PubMed Central

    Wang, Hao; Lovelett, Emilie; Emery, David W.

    2013-01-01

    The chromatin insulator cHS4 can reduce silencing chromosomal position effects and genotoxicity associated with integrating viral vectors. However, the fully active version of this element can also reduce vector titers and is only partially effective. In order to identify alternatives to cHS4, we developed a functional lentiviral vector-based reporter screen for enhancer-blocking insulators. Using this system, we screened candidate sequences that were initially identified by chromatin profiling for binding by CTCF and for DNase hypersensitivity. All 12 analyzed candidates blocked enhancer-promoter activity. The enhancer-blocking activity of the top two candidates was confirmed in two complementary plasmid-based assays. Studies in a gammaretroviral reporter vector indicated these two candidates have little to no effect on vector titers, and do not diminish vector expression in primary mouse bone marrow cultures. Subsequent assessment in a mouse in vivo tumor formation model demonstrated that both candidates reduced the rate of gammaretroviral vector-mediated genotoxicity as effectively as the cHS4 insulator. In summary, we have developed a novel lentiviral vector-based method of screening candidate elements for insulator activity, and have used this method to identify two new insulator elements capable of improving the safety of retroviral vectors without diminishing vector titers or expression. These findings expand the limited arsenal of insulators functionally validated to reduce the rate of retroviral vector-mediated genotoxicity. PMID:24098520

  18. Long terminal repeat of murine retroviral DNAs: sequence analysis, host-proviral junctions, and preintegration site.

    PubMed Central

    Van Beveren, C; Rands, E; Chattopadhyay, S K; Lowy, D R; Verma, I M

    1982-01-01

    The nucleotide sequence of the long terminal repeat (LTR) of three murine retroviral DNAs has been determined. The data indicate that the U5 region (sequences originating from the 5' end of the genome) of various LTRs is more conserved than the U3 region (sequences from the 3' end of the genome). The location and sequence of the control elements such as the 5' cap, "TATA-like" sequences, "CCAAT-box," and presumptive polyadenylic acid addition signal AATAAA in the various LTRs are nearly identical. Some murine retroviral DNAs contain a duplication of sequences within the LTR ranging in size from 58 to 100 base pairs. A variant of molecularly cloned Moloney murine sarcoma virus DNA in which one of the two LTRs integrated into the viral DNA was also analyzed. A 4-base-pair duplication was generated at the site of integration of LTR in the viral DNA. The host-viral junction of two molecularly cloned AKR-murine leukemia virus DNAs (clones 623 and 614) was determined. In the case of AKR-623 DNA, a 3- or 4-base-pair direct repeat of cellular sequences flanking the viral DNA was observed. However, AKR-614 DNA contained a 5-base-pair repeat of cellular sequences. The nucleotide sequence of the preintegration site of AKR-623 DNA revealed that the cellular sequences duplicated during integration are present only once. Finally, a striking homology between the sequences flanking the preintegration site and viral LTRs was observed. Images PMID:6281466

  19. Viral and Cellular Requirements for the Nuclear Entry of Retroviral Preintegration Nucleoprotein Complexes

    PubMed Central

    Matreyek, Kenneth A.; Engelman, Alan

    2013-01-01

    Retroviruses integrate their reverse transcribed genomes into host cell chromosomes as an obligate step in virus replication. The nuclear envelope separates the chromosomes from the cell cytoplasm during interphase, and different retroviral groups deal with this physical barrier in different ways. Gammaretroviruses are dependent on the passage of target cells through mitosis, where they are believed to access chromosomes when the nuclear envelope dissolves for cell division. Contrastingly, lentiviruses such as HIV-1 infect non-dividing cells, and are believed to enter the nucleus by passing through the nuclear pore complex. While numerous virally encoded elements have been proposed to be involved in HIV-1 nuclear import, recent evidence has highlighted the importance of HIV-1 capsid. Furthermore, capsid was found to be responsible for the viral requirement of various nuclear transport proteins, including transportin 3 and nucleoporins NUP153 and NUP358, during infection. In this review, we describe our current understanding of retroviral nuclear import, with emphasis on recent developments on the role of the HIV-1 capsid protein. PMID:24103892

  20. Improved self-inactivating retroviral vectors derived from spleen necrosis virus.

    PubMed Central

    Olson, P; Nelson, S; Dornburg, R

    1994-01-01

    Self-inactivating (SIN) retroviral vectors contain a deletion spanning most of the right long terminal repeat's (LTR's) U3 region. Reverse transcription copies this deletion to both LTRs. As a result, there is no transcription from the 5' LTR, preventing further replication. Many previously developed SIN vectors, however, had reduced titers or were genetically unstable. Earlier, we reported that certain SIN vectors derived from spleen necrosis virus (SNV) experienced reconstitution of the U3-deleted LTR at high frequencies. This reconstitution occurred on the DNA level and appeared to be dependent on defined vector sequences. To study this phenomenon in more detail, we developed an almost completely U3-free retroviral vector. The promoter and enhancer of the left LTR were replaced with those of the cytomegalovirus immediate-early genes. This promoter swap did not impair the level of transcription or alter its start site. Our data indicate that SNV contains a strong initiator which resembles that of human immunodeficiency virus. We show that the vectors replicate with efficiencies similar to those of vectors possessing two wild-type LTRs. U3-deleted vectors carrying the hygromycin B phosphotransferase gene did not observably undergo LTR reconstitution, even when replicated in helper cells containing SNV-LTR sequences. However, vectors carrying the neomycin resistance gene did undergo LTR reconstitution with the use of homologous helper cell LTR sequences as template. This supports our earlier finding that sequences within the neomycin resistance gene can trigger recombination. Images PMID:7933088

  1. Retrovirus Integration Database (RID): a public database for retroviral insertion sites into host genomes.

    PubMed

    Shao, Wei; Shan, Jigui; Kearney, Mary F; Wu, Xiaolin; Maldarelli, Frank; Mellors, John W; Luke, Brian; Coffin, John M; Hughes, Stephen H

    2016-07-04

    The NCI Retrovirus Integration Database is a MySql-based relational database created for storing and retrieving comprehensive information about retroviral integration sites, primarily, but not exclusively, HIV-1. The database is accessible to the public for submission or extraction of data originating from experiments aimed at collecting information related to retroviral integration sites including: the site of integration into the host genome, the virus family and subtype, the origin of the sample, gene exons/introns associated with integration, and proviral orientation. Information about the references from which the data were collected is also stored in the database. Tools are built into the website that can be used to map the integration sites to UCSC genome browser, to plot the integration site patterns on a chromosome, and to display provirus LTRs in their inserted genome sequence. The website is robust, user friendly, and allows users to query the database and analyze the data dynamically. https://rid.ncifcrf.gov ; or http://home.ncifcrf.gov/hivdrp/resources.htm .

  2. Genomic rearrangements of retroviral vectors carrying two genes in F9 EC cells.

    PubMed

    Breuer, B; Steuer, B; Alonso, A

    1993-02-01

    We have used two classes of double-expression retroviral vectors for the expression of foreign genetic information in embryonal carcinoma cell lines. The splice-vector pM5neo takes advantage of mutated sequences that mediate an LTR-driven expression in F9 EC cells. The second vector (pXT1 type) uses an internal HSV-tk promoter as the control element for the transcription of the second gene. Genomic analysis of DNA from infected F9 cell lines revealed that most of the proviruses have rearranged upon integration into the host genome. This reorganization always included the nonselected gene and is sequence independent, but depends on the selective pressure applied. No retroviral genomic rearrangements were observed in F9 cells infected with pM5 proviruses carrying only the neo resistance gene. On the contrary, gross rearrangements were found in cells infected with parental pXT1 retroviruses. In both vectors the transcriptional activity was very low. A direct correlation between selective pressure, proviral reorganization, and transcription was observed.

  3. Moesin regulates stable microtubule formation and limits retroviral infection in cultured cells.

    PubMed

    Naghavi, Mojgan H; Valente, Susana; Hatziioannou, Theodora; de Los Santos, Kenia; Wen, Ying; Mott, Christina; Gundersen, Gregg G; Goff, Stephen P

    2007-01-10

    In a functional screen of mammalian complementary DNA libraries, we identified moesin as a novel gene whose overexpression blocks infection by murine leukemia viruses and human immunodeficiency virus type 1 in human and rodent lines, before the initiation of reverse transcription. Knockdown of moesin by RNA interference resulted in enhanced infection, suggesting that even the endogenous basal levels of moesin in rat fibroblasts are sufficient to limit virus infection. Moesin acts as a crosslinker between plasma membrane and actin filaments, as well as a signal transducer in responses involving cytoskeletal remodeling. Moesin overexpression was found to downregulate the formation of stable microtubules, whereas knockdown of moesin increased stable microtubule formation. A virus-resistant mutant cell line also displayed decreased stable microtubule levels, and virus-sensitive revertants recovered from the mutant line showed restoration of the stable microtubules, suggesting that these cytoskeletal networks play an important role in early post-entry events in the retroviral lifecycle. Together, these results suggest that moesin negatively regulates stable microtubule networks and is a natural determinant of cellular sensitivity to retroviral infection.

  4. High Expression of Endogenous Retroviral Envelope Gene in the Equine Fetal Part of the Placenta

    PubMed Central

    Stefanetti, Valentina; Marenzoni, Maria Luisa; Passamonti, Fabrizio; Cappelli, Katia; Garcia-Etxebarria, Koldo; Coletti, Mauro; Capomaccio, Stefano

    2016-01-01

    Endogenous retroviruses (ERVs) are proviral phases of exogenous retroviruses that have co-evolved with vertebrate genomes for millions of years. Previous studies have identified the envelope (env) protein genes of retroviral origin preferentially expressed in the placenta which suggests a role in placentation based on their membrane fusogenic capacity and therefore they have been named syncytins. Until now, all the characterized syncytins have been associated with three invasive placentation types: the endotheliochorial (Carnivora), the synepitheliochorial (Ruminantia), and the hemochorial placentation (human, mouse) where they play a role in the syncytiotrophoblast formation. The purpose of the present study was to evaluate whether EqERV env RNA is expressed in horse tissues as well and investigate if the horse, possessing an epitheliochorial placenta, has “captured” a common retroviral env gene with syncytin-like properties in placental tissues. Interestingly, although in the equine placenta there is no syncytiotrophoblast layer at the maternal-fetal interface, our results showed that EqERV env RNA is highly expressed at that level, as expected for a candidate syncytin-like gene but with reduced abundance in the other somatic tissues (nearly 30-fold lower) thus suggesting a possible role in the placental tissue. Although the horse is one of the few domestic animals with a sequenced genome, few studies have been conducted about the EqERV and their expression in placental tissue has never been investigated. PMID:27176223

  5. Cytoreductive conditioning intensity predicts clonal diversity in ADA-SCID retroviral gene therapy patients.

    PubMed

    Cooper, Aaron R; Lill, Georgia R; Shaw, Kit; Carbonaro-Sarracino, Denise A; Davila, Alejandra; Sokolic, Robert; Candotti, Fabio; Pellegrini, Matteo; Kohn, Donald B

    2017-05-11

    Retroviral gene therapy has proved efficacious for multiple genetic diseases of the hematopoietic system, but roughly half of clinical gene therapy trial protocols using gammaretroviral vectors have reported leukemias in some of the patients treated. In dramatic contrast, 39 adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) patients have been treated with 4 distinct gammaretroviral vectors without oncogenic consequence. We investigated clonal dynamics and diversity in a cohort of 15 ADA-SCID children treated with gammaretroviral vectors and found clear evidence of genotoxicity, indicated by numerous common integration sites near proto-oncogenes and by increased abundance of clones with integrations near MECOM and LMO2 These clones showed stable behavior over multiple years and never expanded to the point of dominance or dysplasia. One patient developed a benign clonal dominance that could not be attributed to insertional mutagenesis and instead likely resulted from expansion of a transduced natural killer clone in response to chronic Epstein-Barr virus viremia. Clonal diversity and T-cell repertoire, measured by vector integration site sequencing and T-cell receptor β-chain rearrangement sequencing, correlated significantly with the amount of busulfan preconditioning delivered to patients and to CD34(+) cell dose. These data, in combination with results of other ADA-SCID gene therapy trials, suggest that disease background may be a crucial factor in leukemogenic potential of retroviral gene therapy and underscore the importance of cytoreductive conditioning in this type of gene therapy approach.

  6. Retroviral intasomes search for a target DNA by 1D diffusion which rarely results in integration

    PubMed Central

    Jones, Nathan D.; Lopez Jr, Miguel A.; Hanne, Jeungphill; Peake, Mitchell B.; Lee, Jong-Bong; Fishel, Richard; Yoder, Kristine E.

    2016-01-01

    Retroviruses must integrate their linear viral cDNA into the host genome for a productive infection. Integration is catalysed by the retrovirus-encoded integrase (IN), which forms a tetramer or octamer complex with the viral cDNA long terminal repeat (LTR) ends termed an intasome. IN removes two 3′-nucleotides from both LTR ends and catalyses strand transfer of the recessed 3′-hydroxyls into the target DNA separated by 4–6 bp. Host DNA repair restores the resulting 5′-Flap and single-stranded DNA (ssDNA) gap. Here we have used multiple single molecule imaging tools to determine that the prototype foamy virus (PFV) retroviral intasome searches for an integration site by one-dimensional (1D) rotation-coupled diffusion along DNA. Once a target site is identified, the time between PFV strand transfer events is 470 ms. The majority of PFV intasome search events were non-productive. These observations identify new dynamic IN functions and suggest that target site-selection limits retroviral integration. PMID:27108531

  7. Characterisation of cytoplasmic DNA complementary to non-retroviral RNA viruses in human cells

    PubMed Central

    Shimizu, Akira; Nakatani, Yoko; Nakamura, Takako; Jinno-Oue, Atsushi; Ishikawa, Osamu; Boeke, Jef D.; Takeuchi, Yasuhiro; Hoshino, Hiroo

    2014-01-01

    The synthesis and subsequent genomic integration of DNA that is complementary to the genomes of non-retroviral RNA viruses are rarely observed. However, upon infection of various human cell lines and primary fibroblasts with the vesicular stomatitis virus (VSV), we detected DNA complementary to the VSV RNA. The VSV DNA was detected in the cytoplasm as single-stranded DNA fully complementary to the viral mRNA from the poly(A) region to the 7-methyl guanosine cap. The formation of this DNA was cell-dependent. Experimentally, we found that the transduction of cells that do not produce VSV DNA with the long interspersed nuclear element 1 and their infection with VSV could lead to the formation of VSV DNA. Viral DNA complementary to other RNA viruses was also detected in the respective infected human cells. Thus, the genetic information of the non-retroviral RNA virus genome can flow into the DNA of mammalian cells expressing LINE-1-like elements. PMID:24875540

  8. Characterisation of cytoplasmic DNA complementary to non-retroviral RNA viruses in human cells.

    PubMed

    Shimizu, Akira; Nakatani, Yoko; Nakamura, Takako; Jinno-Oue, Atsushi; Ishikawa, Osamu; Boeke, Jef D; Takeuchi, Yasuhiro; Hoshino, Hiroo

    2014-05-30

    The synthesis and subsequent genomic integration of DNA that is complementary to the genomes of non-retroviral RNA viruses are rarely observed. However, upon infection of various human cell lines and primary fibroblasts with the vesicular stomatitis virus (VSV), we detected DNA complementary to the VSV RNA. The VSV DNA was detected in the cytoplasm as single-stranded DNA fully complementary to the viral mRNA from the poly(A) region to the 7-methyl guanosine cap. The formation of this DNA was cell-dependent. Experimentally, we found that the transduction of cells that do not produce VSV DNA with the long interspersed nuclear element 1 and their infection with VSV could lead to the formation of VSV DNA. Viral DNA complementary to other RNA viruses was also detected in the respective infected human cells. Thus, the genetic information of the non-retroviral RNA virus genome can flow into the DNA of mammalian cells expressing LINE-1-like elements.

  9. Switching from zidovudine/lamivudine to tenofovir/emtricitabine improves fat distribution as measured by fat mass ratio.

    PubMed

    Martínez, E; Ribera, E; Clotet, B; Estrada, V; Sanz, J; Berenguer, J; Rubio, R; Pulido, F; Larrousse, M; Curran, A; Negredo, E; Arterburn, S; Ferrer, P; Álvarez, M L

    2015-07-01

    Fat mass ratio (FMR) has been suggested as an objective indicator of abnormal body fat distribution in HIV infection. Although it could provide more comprehensive information on body fat changes than limb fat mass, FMR has scarcely been used in clinical trials examining body fat distribution in HIV-infected patients. A subanalysis of a controlled, randomized clinical trial in virologically suppressed HIV-1-infected men switching from zidovudine (ZDV)/lamivudine (3TC) to emtricitabine (FTC)/tenofovir (TDF) versus continuing on ZDV/3TC was carried out. FMR was assessed by dual X-ray absorptiometry (DEXA) for a period of 72 weeks. Lipoatrophy was defined as FMR ≥ 1.5. Multivariate linear regression models for the change in FMR from baseline were fitted. Sixty-five men were randomized and treated (28 in the FTC/TDF arm and 37 in the ZDV/3TC arm), and 57 completed the study (25 and 32 in each arm, respectively). In the FTC/TDF arm, adjusted mean FMR decreased by 0.52 at week 72 (P = 0.014), and in the ZDV/3TC arm it increased by 0.13 (P = 0.491; P between arms = 0.023). Among subjects with lipoatrophy (baseline FMR ≥ 1.5), adjusted FMR decreased by 0.76 (P = 0.003) in the FTC/TDF arm and increased by 0.21 (P = 0.411; P between arms = 0.009) in the ZDV/3TC arm. Baseline FMR and treatment group were significant predictors (P < 0.05) of post-baseline changes in FMR. Switching from ZDV/3TC to FTC/TDF led to an improvement in FMR, compared with progressive worsening of FMR in subjects receiving ZDV/3TC, showing that fat mass not only increased but was also distributed in a healthier way after the switch. © 2014 British HIV Association.

  10. In utero exposure to zidovudine and heart anomalies in the ANRS French perinatal cohort and the nested PRIMEVA randomized trial.

    PubMed

    Sibiude, Jeanne; Le Chenadec, Jérôme; Bonnet, Damien; Tubiana, Roland; Faye, Albert; Dollfus, Catherine; Mandelbrot, Laurent; Delmas, Sandrine; Lelong, Nathalie; Khoshnood, Babak; Warszawski, Josiane; Blanche, Stéphane

    2015-07-15

    Antiretroviral (ARV) regimens during pregnancy are highly effective in preventing mother-to-child transmission of human immunodeficiency virus (HIV). Congenital heart defects (CHDs) and anomalies in cardiac function have been reported in zidovudine (ZDV)-exposed uninfected children. We explored these associations in a large observational cohort and a randomized clinical trial. Since 1986, the French Perinatal Cohort prospectively enrolled all HIV-infected women in 90 centers and collected follow-up on their children through 2 years of age. All CHDs were reviewed by a specialist blinded to exposures. Additionally, in a randomized trial (PRIMEVA ANRS 135) of 2 ARV regimens during pregnancy, 1 of which was without nucleoside reverse transcriptase inhibitors, infants had a specific follow-up including echocardiography at 1 month and 12 months. Among 12 888 children included, ZDV exposure in the first trimester was significantly associated with CHD (1.5% vs 0.7%; adjusted odds ratio, 2.2 [95% confidence interval, 1.3-3.7]; P < .001). This association was significant for ventricular septal defects (1.1% vs 0.6%; P = .001) and other CHDs (0.31% vs 0.11%; P = .02). In the randomized trial, among 50 infants, girls (but not boys) exposed in utero to ZDV/lamivudine/ritonavir-boosted lopinavir (LPV/r) had a higher left ventricular shortening fraction at 1 month (40% vs 36%; P = .008), and an increased posterior wall thickness at 1 year (5.4 mm vs 4.4 mm; P = .01) than the LPV/r group. This study confirms a specific association between in utero exposure to ZDV and CHDs, and a long-lasting postnatal myocardial remodeling in girls. A potential common mechanism, including the involvement of mitochondrial dysfunction, must be explored, and long-term consequences on cardiac function warrant specific attention. NCT00424814. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e

  11. Intracellular zidovudine (ZDV) and ZDV phosphates as measured by a validated combined high-pressure liquid chromatography-radioimmunoassay procedure.

    PubMed Central

    Slusher, J T; Kuwahara, S K; Hamzeh, F M; Lewis, L D; Kornhauser, D M; Lietman, P S

    1992-01-01

    In vitro studies of zidovudine (ZDV) phosphorylation may not accurately reflect the in vivo dose-response relationship, which is crucial to determining the relationship between ZDV exposure, efficacy, and toxicity. However, measurement of ZDV phosphorylated anabolites in peripheral blood mononuclear cells (PBMCs) from ZDV-treated human immunodeficiency virus (HIV)-infected patients would be extremely useful in the more appropriate utilization of ZDV in the treatment of HIV infection. We developed a specific and sensitive combined high-pressure liquid chromatography (HPLC)-radioimmunoassay (RIA) procedure for the determination of ZDV, ZDV-monophosphate, ZDV-diphosphate, and ZDV-triphosphate in PBMCs taken from ZDV-treated HIV-infected patients.