Photophysical and Chiroptical Properties of the Enantiomers of N,N'-Bis(1-phenylpropyl)-2,6-pyridinecarboxamide and their Chiral 9-Coordinate Ln3+ Complexes.

The R,R and S,S enantiomers of N,N'-bis(1-phenylpropyl)-2,6-pyridinedicarboxamide, L(Et), react with Ln3+ ions (Ln = La, Eu, Gd, and Tb) to give stable [Ln((R,R)- and (S,S)-L(Et))3]3+ in anhydrous acetonitrile solution, as evidenced by various spectroscopic measurements, including NMR and luminescence titrations. In addition to the characteristic Eu3+ and Tb3+ luminescence bands, the steady-state and time-resolved luminescence spectra of the aforementioned complexes show the residual ligand-centered emission of the 1ππ* to 3ππ* states, indicating an incomplete intersystem crossing (ISC) transfer from the 1ππ* to 3ππ* and ligand-to-Ln3+ energy transfer, respectively. The high circularly polarized luminescence (CPL) activity of [Eu(L(Et))3]3+ confirms that using a single enantiomer of L(Et) induces the preferential formation of one chiral [Eu(L(Et))3]3+ complex, consistent with the [EuL 3]3+ complexes formed with other ligands derived from a 2,6-pyridine dicarboxamide moiety. Furthermore, the CPL sign patterns of complexes with (R,R) or (S,S) enantiomer of L(Et) are consistent with the CPL sign pattern of related [LnL 3]3+ complexes with the (R,R) or (S,S) enantiomer of the respective ligands in this family.

Antiretroviral Activity of AMD11070 (An Orally Administered CXCR4 Entry Inhibitor): Results of NIH/NIAID AIDS Clinical Trials Group Protocol A5210.

AMD11070 binds to the chemokine receptor CXCR4, with anti-HIV-1 activity in vitro and in vivo. We conducted a phase IB/IIA proof-of-concept dose-escalating, open-label study to determine safety and antiviral activity of AMD11070 administered over 10 days to HIV-1-infected participants who harbored CXCR4-tropic virus. Primary endpoints were ≥1 log10 rlu (relative luminescence units) reduction in CXCR4-tropic virus during 10 days of AMD11070 treatment or in the 7 days following treatment discontinuation, rlu changes over 10 days of treatment, and safety. Plasma pharmacokinetic parameters, HIV-1 RNA, and safety labs were obtained over 90 days of study. The study was stopped early due to emerging AMD11070 animal toxicity data. Six HIV-infected participants with plasma HIV-1 RNA ≥5,000 copies/mL on no antiretroviral therapy for 14 days before entry were treated. AMD11070 was well-tolerated when administered at 200 mg orally every 12 h for 10 days. All enrolled participants had dual/mixed (D/M) viruses. Reductions of almost 1 log10 rlu or more in CXCR4 virus were seen in three of six participants after 10 days of treatment. No participants had ≥1 log10 decline in plasma HIV-1 RNA from baseline at day 10. No clear relationship between pharmacokinetic parameters and response to therapy (X4 log rlu reduction) was observed. AMD11070 demonstrated in vivo activity as measured by reductions in CXCR4 rlu signal. Despite the finding of discordant rlu and plasma HIV RNA responses in these participants with D/M viruses, exploration of other HIV-1 CXCR4 antagonist therapies is possible.

Improving the Impact and Implementation of Disaster Education: Programs for Children Through Theory-Based Evaluation.

A main weakness in the evaluation of disaster education programs for children is evaluators' propensity to judge program effectiveness based on changes in children's knowledge. Few studies have articulated an explicit program theory of how children's education would achieve desired outcomes and impacts related to disaster risk reduction in households and communities. This article describes the advantages of constructing program theory models for the purpose of evaluating disaster education programs for children. Following a review of some potential frameworks for program theory development, including the logic model, the program theory matrix, and the stage step model, the article provides working examples of these frameworks. The first example is the development of a program theory matrix used in an evaluation of ShakeOut, an earthquake drill practiced in two Washington State school districts. The model illustrates a theory of action; specifically, the effectiveness of school earthquake drills in preventing injuries and deaths during disasters. The second example is the development of a stage step model used for a process evaluation of What's the Plan Stan?, a voluntary teaching resource distributed to all New Zealand primary schools for curricular integration of disaster education. The model illustrates a theory of use; specifically, expanding the reach of disaster education for children through increased promotion of the resource. The process of developing the program theory models for the purpose of evaluation planning is discussed, as well as the advantages and shortcomings of the theory-based approaches.

2017 Update of the Drug Resistance Mutations in HIV-1.

The 2017 edition of the IAS-USA drug resistance mutations list updates the figures last published in November 2015. The mutations listed are those that have been identified by specific criteria for evidence and drugs described. The figures are designed to assist practitioners in identifying key mutations associated with resistance to antiretroviral drugs and, therefore, in making clinical decisions regarding antiretroviral therapy.

2015 Update of the Drug Resistance Mutations in HIV-1.

The 2015 edition of the IAS-USA drug resistance mutations list updates the figures last published in July 2014. The mutations listed are those that have been identified by specific criteria for evidence and drugs described. The figures are designed to assist practitioners in identifying key mutations associated with resistance to antiretroviral drugs and, therefore, in making clinical decisions regarding antiretroviral therapy.

HIV Salvage Therapy Does Not Require Nucleoside Reverse Transcriptase Inhibitors: A Randomized, Controlled Trial.

BACKGROUND: Nucleoside reverse transcriptase inhibitors (NRTIs) are often included in antiretroviral regimens in treatment-experienced patients in the absence of data from randomized trials. OBJECTIVE: To compare treatment success between participants who omit versus those who add NRTIs to an optimized antiretroviral regimen of 3 or more agents. DESIGN: Multicenter, randomized, controlled trial. (ClinicalTrials.gov: NCT00537394). SETTING: Outpatient HIV clinics. PARTICIPANTS: Treatment-experienced patients with HIV infection and viral resistance. INTERVENTION: Open-label optimized regimens (not including NRTIs) were selected on the basis of treatment history and susceptibility testing. Participants were randomly assigned to omit or add NRTIs. MEASUREMENTS: The primary efficacy outcome was regimen failure through 48 weeks using a noninferiority margin of 15%. The primary safety outcome was time to initial episode of a severe sign, symptom, or laboratory abnormality before discontinuation of NRTI assignment. RESULTS: 360 participants were randomly assigned, and 93% completed a 48-week visit. The cumulative probability of regimen failure was 29.8% in the omit-NRTIs group versus 25.9% in the add-NRTIs group (difference, 3.2 percentage points [95% CI, -6.1 to 12.5 percentage points]). No significant between-group differences were found in the primary safety end points or the proportion of participants with HIV RNA level less than 50 copies/mL. No deaths occurred in the omit-NRTIs group compared with 7 deaths in the add-NRTIs group. LIMITATION: Unblinded study design, and the study may not be applicable to resource-poor settings. CONCLUSION: Treatment-experienced patients with HIV infection starting a new optimized regimen can safely omit NRTIs without compromising virologic efficacy. Omitting NRTIs will reduce pill burden, cost, and toxicity in this patient population. PRIMARY FUNDING SOURCES: National Institute of Allergy and Infectious Diseases, Boehringer Ingelheim, Janssen, Merck, ViiV Healthcare, Roche, and Monogram Biosciences (LabCorp).

Regimen selection in the OPTIONS trial of HIV salvage therapy: drug resistance, prior therapy, and race-ethnicity determine the degree of regimen complexity.

BACKGROUND: Regimen selection for highly treatment-experienced patients is complicated. METHODS: Using a web-based utility, study team members reviewed antiretroviral (ARV) history and resistance data and recommended individual ARV regimens and nucleoside reverse transcriptase inhibitor (NRTI) options for treatment-experienced participants consisting of 3-4 of the following agents: raltegravir (RAL), darunavir (DRV)/ritonavir, tipranavir (TPV)/ritonavir, etravirine (ETR), maraviroc (MVC), and enfuvirtide (ENF). We evaluated team recommendations and site selection of regimen and NRTIs. Associations between baseline factors and the selection of a complex regimen (defined as including four ARV agents or ENF) were explored with logistic regression. RESULTS: A total of 413 participants entered the study. Participants initiated the first or second recommended regimen 86% of the time and 21% of participants started a complex regimen. In a multivariable model, ARV resistance to NRTI (odds ratio [OR] = 2.2), non-nucleoside reverse transcriptase inhibitor (NNRTI, OR = 6.2) or boosted protease inhibitor (PI, OR = 6.6), prior use of integrase strand transfer inhibitor (INSTI, OR = 25), and race-ethnicity (all P ≤ 0.01) were associated with selection of a complex regimen. Black non-Hispanic (OR = 0.5) and Hispanic participants from the continental US (OR = 0.2) were less likely to start a complex regimen, compared to white non-Hispanics. CONCLUSIONS: In this multi-center trial, we developed a web-based utility that facilitated treatment recommendations for highly treatment-experienced patients. Drug resistance, prior INSTI use, and race-ethnicity were key factors in decisions to select a more complex regimen.

Comparison of Three Different FDA-Approved Plasma HIV-1 RNA Assay Platforms Confirms the Virologic Failure Endpoint of 200 Copies per Milliliter Despite Improved Assay Sensitivity.

Discrepancies between HIV-1 RNA results assayed by different FDA-approved platforms have been reported. Plasma samples collected from 332 randomly selected clinical trial participants during the second year of antiretroviral treatment were assayed with three FDA-approved platforms: UltraSensitive Roche Amplicor Monitor, v1.5 (Monitor), the Abbott RealTime HIV-1 test on the m2000 system (Abbott), and the Roche TaqMan HIV-1 test, v2.0 (TaqMan). Samples from 61 additional participants with confirmed HIV-1 RNA levels of >50 copies/ml during trial follow-up were also included. Endpoints were HIV-1 RNA quantification of ≤50 copies/ml versus >50 copies/ml at an individual-sample level (primary) and determination of confirmed virologic failure (VF) from longitudinal samples. A total of 389 participants had results obtained from all assays on at least one sample (median = 6). Proportions of results of >50 copies/ml were 19% (Monitor), 22% (TaqMan), and 25% (Abbott). Despite indication of strong agreement (Cohen's kappa, 0.76 to 0.82), Abbott was more likely to detect HIV-1 RNA levels of >50 copies/ml than Monitor (matched-pair odds ratio [mOR] = 4.2; modified Obuchowski P < 0.001) and TaqMan (mOR = 2.1; P < 0.001); TaqMan was more likely than Monitor (mOR = 2.6; P < 0.001). Despite strong agreement in classifying VF across assay comparisons (kappa, 0.75 to 0.92), at a 50-copies/ml threshold, differences in the probability of VF classification (in the same direction as primary) were apparent (all McNemar's P < 0.007). At a 200-copies/ml VF threshold, no differences between assays were apparent (all P > 0.13). Despite strong agreement among assays, significant differences were observed with respect to detecting HIV-1 RNA levels of >50 copies/ml and identifying VF at the 50-copies/ml threshold. This has important implications for the definition of VF in clinical trials and clinical practice.

Disaster preparedness for children and families: a critical review.

Preparedness for disasters is universally low; children and families are particularly vulnerable groups. Against this backdrop, research on disaster preparedness for children and families is reviewed, with a focus on disaster preparedness and prevention education programs. Following definitions and theory/rationale, research is critically analyzed. While findings indicate a large growth in research in the past 15 years and largely positive findings, significant challenges remain. These challenges include issues related to methodological rigor, long-term effectiveness, and implementation. Recent research reflecting these important challenges is reviewed. At the same time, other recent research documents real potential for these programs, including findings which suggest that increased attention to incorporating theory- and evidence-supported components can enhance outcomes. Thus, despite some important limitations and challenges, research done to date signals promise for these programs in reducing risk and increasing resilience to disasters for children, families, and the households and communities in which they live.

2014 Update of the drug resistance mutations in HIV-1.

This July 2014 edition of the IAS-USA drug resistance mutations list updates the figures last published in March 2013. The following mutations have been added to existing classes or drugs: K65E/N has been added to the bars for the nucleoside and nucleotide analogue reverse transcriptase inhibitors (nRTIs) abacavir, didanosine, emtricitabine, lamivudine, stavudine, and tenofovir; L100I has been added to the bar for the nonnucleoside analogue reverse transcriptase inhibitor (NNRTI) rilpivirine; and F121Y has been added to the bars for the integrase strand transfer inhibitors (InSTIs) dolutegravir, elvitegravir, and raltegravir. With regard to protease inhibitors (PIs), it cannot be excluded that drug resistance may be selected for outside the protease encoding region.

Combination antiretroviral treatment for women previously treated only in pregnancy: week 24 results of AIDS clinical trials group protocol a5227.

BACKGROUND: Women with HIV and prior exposure to combination antiretroviral therapy (cART) solely for prevention of mother-to-child transmission (pMTCT) need to know whether they can later be treated successfully with a commonly used regimen of efavirenz (EFV) and coformulated emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF). METHODS: Nonpregnant women with plasma HIV-1 RNA of ≥500 copies per milliliter, previously cART exposed for pMTCT only, were eligible if they were off ART for ≥24 weeks before entry, were without evidence of drug resistance on standard genotyping, and were ready to start EFV plus FTC/TDF. The primary endpoint was virologic response (defined as plasma HIV RNA <400 copies/mL) at 24 weeks. RESULTS: Fifty-four women were enrolled between October 2007 and December 2009; 52 of 54 completed 24 weeks of follow-up. Median baseline CD4 T-cell count was 265/mm and baseline plasma HIV-1 RNA was 4.6 log10 copies per milliliter. Median prior cART duration was 14 weeks, and median time elapsed from the last pMTCT dose to entry was 22 months. Virologic response at 24 weeks was observed in 42 of 52 women or 81% (exact 95% confidence interval: 68% to 90%). There were no differences in response by country, by number, or class of prior pMTCT exposures. Although confirmed virologic failure occurred in 8 women, no virologic failures were observed in women reporting perfect early adherence. CONCLUSIONS: In this first prospective clinical trial studying combination antiretroviral retreatment in women with a history of pregnancy-limited cART, the observed virologic response to TDF/FTC and EFV at 24 weeks was 81%. Virologic failures occurred and correlated with self-reported nonadherence.

Safety and antiviral activity of the HCV entry inhibitor ITX5061 in treatment-naive HCV-infected adults: a randomized, double-blind, phase 1b study.

BACKGROUND: Hepatitis C virus (HCV) entry involves scavenger receptor B1 (SRB1). In vitro, SRB1 inhibition by ITX5061 impedes HCV replication. METHODS: Multicenter study to assess safety/activity of ITX5061 in previously untreated, noncirrhotic, HCV genotype 1 infected adults. Design included sequential cohorts of 10 subjects with ITX5061 (n = 8) or placebo (n = 2) to escalate duration (3 to 14 to 28 days) or deescalate dose (150 to 75 to 25 mg) based on predefined criteria for safety and activity (≥ 4 of 8 subjects with HCV RNA decline ≥ 1 log10 IU/mL). RESULTS: Thirty subjects enrolled in 3 cohorts: ITX5061 150 mg/day by mouth for 3 (A150), 14 (B150), and 28 (C150) days. Six subjects had grade ≥ 3 adverse events (one in placebo); none were treatment related. One of the 7 C150 subjects (14.3%, 95% confidence interval [CI], .7%-55.4%) had ≥ 1 log10 IU/mL decline in HCV RNA (1.49 log10 IU/mL), whereas none of the 6 placebo, 8 A150 or 8 B150 subjects showed such decline. CONCLUSIONS: Oral ITX5061 150 mg/day for up to 28 days was safe and well tolerated. In the 28-day cohort, 1 of 7 subjects showed antiviral activity; however, predefined criteria for antiviral activity were not met at the doses and durations studied.

Addition of nitazoxanide to PEG-IFN and ribavirin to improve HCV treatment response in HIV-1 and HCV genotype 1 coinfected persons naïve to HCV therapy: results of the ACTG A5269 trial.

BACKGROUND: We hypothesized that nitazoxanide (NTZ) added to pegylated interferon alfa-2a (PEG-IFN) and weight-based ribavirin (WBR) would improve hepatitis C virus (HCV) virologic responses in HCV treatment-naïve HIV-1/HCV genotype 1 coinfected persons. METHODS: Prospective, single-arm study in which subjects received 4-week lead-in (NTZ 500 mg twice daily) followed by 48 weeks of NTZ, PEG-IFN, and WBR. We compared the HCV virologic responses of these subjects to historical controls from the completed ACTG study A5178 who received PEG-IFN and WBR and had similar subject characteristics. Primary endpoints were early virologic response and complete early virologic response (EVR and cEVR). RESULTS: Among 67 subjects (78% male; 48% Black; median age, 50 years), EVR was achieved in 65.7% (90% CI, 55.0%-75.3%), cEVR in 38.8% (28.8%-49.6%). and SVR in 32.8% (23.4%-43.5%). EVR was higher with NTZ (51.4% in A5178; P = .03), but the sustained virologic response (SVR) proportion was similar (27.3% in A5178; P = .24). In contrast to A5178, SVR was similar across IL28B genotypes. Overall, NTZ was safe and well-tolerated. CONCLUSION: Whereas EVR proportion improved significantly in this pilot study, the addition of NTZ to PEG-IFN/WBR did not significantly improve SVR compared to historical controls. NTZ may be associated with an attenuation of the effect of IL28B on HCV treatment response.

Risk of vancomycin-induced nephrotoxicity in the population with chronic kidney disease.

The antibiotic vancomycin has been available since the 1950s but has been used more commonly since the early 1980s because of the widespread appearance of methicillin-resistant Staphylococcus aureus. Infectious Diseases Society of America guidelines recommend achieving vancomycin trough levels of 10 to 20 µg/mL. Usage of vancomycin in high dosages especially ≥ 4 g/d has led to an increase in the incidence of vancomycin-induced nephrotoxicity, particularly in patients with chronic kidney disease (CKD). This review focuses on the impact of vancomycin-induced nephrotoxicity in patients with CKD. Patients with CKD are at increased risk of developing acute kidney injury and subsequently requiring renal replacement therapy. There is substantial need for vancomycin pharmacokinetic studies to be performed in the population with CKD to develop an optimum vancomycin nomogram in these patients. At present, tight monitoring of vancomycin trough levels in the population with CKD is recommended to help prevent acute kidney injury and its associated high morbidity, mortality and health care costs.

ITX 5061 quantitation in human plasma with reverse phase liquid chromatography and mass spectrometry detection.

BACKGROUND: ITX 5061 is a highly potent small molecule inhibitor of scavenger receptor-B1, an integral transmembrane protein that is found in liver cells and is actively involved in the transport of HCV into hepatocytes. Currently, ITX 5061 is being investigated in monoinfected hepatitis C patients in a proof-of-concept clinical trial carried out by the AIDS Clinical Trial Group (ACTG). METHODS: To provide quantitative results in human plasma for pharmacokinetic analysis, an assay for ITX 5061 was validated. ITX 5061 and the internal standard, a deuterated analogue, were separated by isocratic reverse phase chromatography using a Polar RP column (Phenomenex Synergi(™); 2.0 mm × 50 mm, 4 µm) and detected via electrospray coupled to a triple quadrupole mass spectrometer with a run time of 5 min. Multiple reaction monitoring in positive mode was used with ITX 5061 at 585/114 m/z and the internal standard at 592/122 m/z with a linear range of 2.50-5,000 ng/ml. Human plasma was extracted using a protein precipitation combing 400 µl of acetonitrile with 100 µl of EDTA plasma. RESULTS: The interassay variation ranged from 1.19 to 13.2%, while the intraassay variation ranged from 0.394 to 12.9% over 6 days of testing. The method was successfully applied to the samples collected for the ACTG Protocol A5277. Plasma concentrations at 1 h and 24 h following 150 mg ITX 5061 daily in HCV monoinfected patients (n=3) ranged from 138 to 518 ng/ml and 33 to 111 ng/ml, respectively. CONCLUSIONS: The ITX 5061 assay is accurate and reproducible with a wide linear range and will be used for pharmacokinetic analysis and dose-finding studies in HCV-monoinfected patients.

2011 update of the drug resistance mutations in HIV-1.

This November 2011 edition of the IAS-USA drug resistance mutations list updates the figures last published in December 2010 (Johnson VA et al, Top HIV Med, 2010;18:156-163).

Macrocycles that inhibit the binding between heat shock protein 90 and TPR-containing proteins.

Heat shock protein 90 (Hsp90) accounts for 1-2% of the total proteins in normal cells and functions as a molecular chaperone that folds, assembles, and stabilizes client proteins. Hsp90 is overexpressed (3- to 6-fold increase) in stressed cells, including cancer cells, and regulates over 200 client and co-chaperone proteins. Hsp90 client proteins are involved in a plethora of cellular signaling events including numerous growth and apoptotic pathways. Since pathway-specific inhibitors can be problematic in drug-resistant cancers, shutting down multiple pathways at once is a promising approach when developing new therapeutics. Hsp90's ability to modulate many growth and signaling pathways simultaneously makes this protein an attractive target in the field of cancer therapeutics. Herein we present evidence that a small molecule modulates Hsp90 via binding between the N and middle domain and allosterically inhibiting the binding interaction between Hsp90 and four C-terminal binding client proteins: IP6K2, FKBP38, FKBP52, and HOP. These last three clients contain a tetratricopeptide-repeat (TPR) region, which is known to interact with the MEEVD sequence on the C-terminus of Hsp90. Thus, this small molecule modulates the activity between co-chaperones that contain TPR motifs and Hsp90's MEEVD region. This mechanism of action is unique from that of all Hsp90 inhibitors currently in clinical trials where these molecules have no effect on proteins that bind to the C-terminus of Hsp90. Further, our small molecule induces a Caspase-3 dependent apoptotic event. Thus, we describe the mechanism of a novel scaffold that is a useful tool for studying cell-signaling events that result when blocking the MEEVD-TPR interaction between Hsp90 and co-chaperone proteins.

Design and synthesis of Hsp90 inhibitors: exploring the SAR of Sansalvamide A derivatives.

Utilizing the structure-activity relationship we have developed during the synthesis of the first two generations and mechanism of action studies that point to the interaction of these molecules with the key oncogenic protein Hsp90, we report here the design of 32 new Sansalvamide A derivatives and their synthesis. Our new structures, designed from previously reported potent compounds, were tested for cytotoxicity on the HCT116 colon cancer cell line, and their binding to the biological target was analyzed using computational studies involving blind docking of derivatives using Autodock. Further, we show new evidence that our molecules bind directly to Hsp90 and modulate Hsp90's binding with client proteins. Finally, we demonstrate that we have integrated good ADME properties into a new derivative.