43 results on '"Hartman TL"'
Search Results
2. Using an Adaptive Listening Tour and Survey to Promote Faculty Reflection on Diversity, Equity, and Inclusion (DEI) in the Pre-clinical Undergraduate Medical Curriculum.
- Author
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Fadul N, Boyland R, Nelson KL, Hartman TL, Oldenburg P, Mott JL, and Delair S
- Abstract
Descriptive studies regarding how to integrate diversity, equity, and inclusion (DEI) into medical education are lacking. We utilized the AAMC's Key Steps for Assessing Institutional Culture and Climate framework to evaluate our current curriculum via listening tours ( n = 34 participants) and a survey of the 10 pre-clinical block directors, to better understand the opportunities and challenges of improving DEI in the pre-clinical curriculum. Opportunities included diversifying cases and standardized patients, enhancing information on systemic racism and social determinants of health, and increasing racial humility and population genetics/epigenetics training. Faculty had issues with "correct ways" to incorporate DEI and time constraints., Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01924-7., Competing Interests: Conflict of InterestThe authors declare no competing interests., (© The Author(s) under exclusive licence to International Association of Medical Science Educators 2023.)
- Published
- 2023
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3. Landscape of health sciences librarian-mediated search services.
- Author
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Westmark DM, Hartman TL, and Schmidt CM
- Subjects
- Humans, Library Associations, Surveys and Questionnaires, Librarians, Libraries, Medical, Library Services
- Abstract
Background: Health librarians have traditionally provided mediated searches to support patient care, education and research., Objectives: This study aims to discover the types of search result formats used by health science libraries, determine current practice among health science libraries (types of requesters served, fees, deduplication, turnaround time and citation manager use) and uncover innovative methods for providing search results., Methods: An online survey was distributed to the MEDLIB-L, ExpertSearching, MidContinental Chapter of the Medical Library Association and ICON listservs and through direct email to selected Association of Academic Health Sciences Libraries reference and education librarians., Results: Librarians affiliated with 127 institutions from 11 countries (including the USS) and 36 USS states and territories responded. One hundred and forty-two of the total 150 analysed responses provided information on full-text access, and 81 of those 142 responses (57%) indicated that the institutions' link-resolver links were included in search results provided to the requester. The survey responses provide information on literature search services regarding turnaround time, use of a citation managers, fees and deduplication., Conclusion: With the developing landscape of citation managers and the tools offered, these data can be used as a benchmark for librarians who are considering evaluating or modifying their search service delivery., (© 2022 The Authors Health Information and Libraries Journal published by John Wiley & Sons Ltd on behalf of Health Libraries Group.)
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- 2022
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4. In vitro effect of a non-immunosuppressive FKBP ligand, FK1706, on SARS-CoV-2 replication in combination with antivirals.
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Fitzsimmons WE, Hartman TL, Mendenhall M, and Chen CZ
- Abstract
FKBP, a naturally occurring ubiquitous intracellular protein, has been proposed as a potential target for coronavirus replication. A non-immunosuppressive FKBP ligand, FK1706, was studied in vitro in a Vero cell model to assess potential activity alone and in combination with antivirals against SARS-CoV-2 replication. When combined with remdesivir, synergistic activity was seen (summary synergy score 24.7±9.56). FK1706 warrants in vivo testing as a potential new combination therapeutic for the treatment of COVID-19 infections.
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- 2022
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5. The structure-activity profile of mercaptobenzamides' anti-HIV activity suggests that thermodynamics of metabolism is more important than binding affinity to the target.
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Nikolayevskiy H, Robello M, Scerba MT, Pasternak EH, Saha M, Hartman TL, Buchholz CA, Buckheit RW Jr, Durell SR, and Appella DH
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- Anti-HIV Agents chemistry, Benzamides chemistry, Dose-Response Relationship, Drug, Humans, Microbial Sensitivity Tests, Molecular Dynamics Simulation, Molecular Structure, Structure-Activity Relationship, Anti-HIV Agents metabolism, Anti-HIV Agents pharmacology, Benzamides metabolism, Benzamides pharmacology, HIV-1 drug effects, Thermodynamics
- Abstract
Mercaptobenzamide thioesters and thioethers are chemically simple HIV-1 maturation inhibitors with a unique mechanism of action, low toxicity, and a high barrier to viral resistance. A structure-activity relationship (SAR) profile based on 39 mercaptobenzamide prodrug analogs exposed divergent activity/toxicity roles for the internal and terminal amides. To probe the relationship between antiviral activity and toxicity, we generated an improved computational model for the binding of mercaptobenzamide thioesters (SAMTs) to the HIV-1 NCp7 C-terminal zinc finger, revealing the presence of a second low-energy binding orientation, hitherto undisclosed. Finally, using NMR-derived thiol-thioester exchange equilibrium constants, we propose that thermodynamics plays a role in determining the antiviral activity observed in the SAR profile., (Copyright © 2019. Published by Elsevier Masson SAS.)
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- 2019
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6. Neurobehavioral Management of the Polytrauma Veteran.
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Merritt BP, Kretzmer T, McKenzie-Hartman TL, and Gootam P
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- Disease Management, Humans, Multiple Trauma physiopathology, Multiple Trauma psychology, United States, United States Department of Veterans Affairs, Multiple Trauma rehabilitation, Veterans
- Abstract
Since the inception of the Afghanistan and Iraq wars, an increasing number of veterans have sought treatment from the Department of Veterans Affairs for combat-related injuries. Many veterans experience postconcussive symptoms, traumatic stress, chronic pain, sensory deficits, and/or headaches. The goal of this article was to highlight some of the challenges treatment providers may face, while providing rehabilitation specialists with important evaluation and treatment considerations in working with this population to maximize outcomes for these veterans., (Published by Elsevier Inc.)
- Published
- 2019
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7. Probing Mercaptobenzamides as HIV Inactivators via Nucleocapsid Protein 7.
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Saha M, Scerba MT, Shank NI, Hartman TL, Buchholz CA, Buckheit RW Jr, Durell SR, and Appella DH
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- Anti-HIV Agents chemical synthesis, Anti-HIV Agents chemistry, Benzamides chemical synthesis, Benzamides chemistry, Dose-Response Relationship, Drug, HIV metabolism, Humans, Microbial Sensitivity Tests, Models, Molecular, Molecular Structure, Prodrugs chemical synthesis, Prodrugs chemistry, Structure-Activity Relationship, Sulfhydryl Compounds chemical synthesis, Sulfhydryl Compounds chemistry, Anti-HIV Agents pharmacology, Benzamides pharmacology, HIV drug effects, Prodrugs pharmacology, Sulfhydryl Compounds pharmacology, gag Gene Products, Human Immunodeficiency Virus antagonists & inhibitors
- Abstract
Human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein 7 (NCp7), a zinc finger protein, plays critical roles in viral replication and maturation and is an attractive target for drug development. However, the development of drug-like molecules that inhibit NCp7 has been a significant challenge. In this study, a series of novel 2-mercaptobenzamide prodrugs were investigated for anti-HIV activity in the context of NCp7 inactivation. The molecules were synthesized from the corresponding thiosalicylic acids, and they are all crystalline solids and stable at room temperature. Derivatives with a range of amide side chains and aromatic substituents were synthesized and screened for anti-HIV activity. Wide ranges of antiviral activity were observed, with IC
50 values ranging from 1 to 100 μm depending on subtle changes to the substituents on the aromatic ring and side chain. Results from these structure-activity relationships were fit to a probable mode of intracellular activation and interaction with NCp7 to explain variations in antiviral activity. Our strategy to make a series of mercaptobenzamide prodrugs represents a general new direction to make libraries that can be screened for anti-HIV activity., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2017
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8. An analog of camptothecin inactive against Topoisomerase I is broadly neutralizing of HIV-1 through inhibition of Vif-dependent APOBEC3G degradation.
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Bennett RP, Stewart RA, Hogan PA, Ptak RG, Mankowski MK, Hartman TL, Buckheit RW Jr, Snyder BA, Salter JD, Morales GA, and Smith HC
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- APOBEC-3G Deaminase genetics, Camptothecin pharmacology, Cell Line, Drug Resistance, Viral genetics, Genome, Viral, HIV Infections virology, HIV-1 genetics, HIV-1 physiology, Humans, Models, Molecular, Mutation, Protein Binding, Protein Multimerization drug effects, Virion metabolism, Virus Replication, vif Gene Products, Human Immunodeficiency Virus chemistry, APOBEC-3G Deaminase metabolism, Camptothecin analogs & derivatives, DNA Topoisomerases, Type I metabolism, HIV-1 drug effects, vif Gene Products, Human Immunodeficiency Virus metabolism
- Abstract
Camptothecin (CPT) is a natural product discovered to be active against various cancers through its ability to inhibit Topoisomerase I (TOP1). CPT analogs also have anti-HIV-1 (HIV) activity that was previously shown to be independent of TOP1 inhibition. We show that a cancer inactive CPT analog (O2-16) inhibits HIV infection by disrupting multimerization of the HIV protein Vif. Antiviral activity depended on the expression of the cellular viral restriction factor APOBEC3G (A3G) that, in the absence of functional Vif, has the ability to hypermutate HIV proviral DNA during reverse transcription. Our studies demonstrate that O2-16 has low cytotoxicity and inhibits Vif-dependent A3G degradation, enabling A3G packaging into HIV viral particles that results in A3G signature hypermutations in viral genomes. This antiviral activity was A3G-dependent and broadly neutralizing against sixteen HIV clinical isolates from groups M (subtypes A-G), N, and O as well as seven single and multi-drug resistant strains of HIV. Molecular modeling predicted binding near the PPLP motif crucial for Vif multimerization and activity. O2-16 also was active in blocking Vif degradation of APOBEC3F (A3F). We propose that CPT analogs not active against TOP1 have novel therapeutic potential as Vif antagonists that enable A3G-dependent hypermutation of HIV., Competing Interests: statement H.C.S. is the founder, CEO and president of OyaGen, Inc. and R.P.B. is the company’s CSO and lab director. Therefore, these individuals have a financial interest in the development of Vif antagonists as a treatment for HIV/AIDS., (Copyright © 2016 Elsevier B.V. All rights reserved.)
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- 2016
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9. Preclinical evaluation of a mercaptobenzamide and its prodrug for NCp7-targeted inhibition of human immunodeficiency virus.
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Hartman TL, Yang L, Helfrick AN, Hassink M, Shank NI, George Rosenker K, Scerba MT, Saha M, Hughes E, Wang AQ, Xu X, Gupta P, Buckheit RW Jr, and Appella DH
- Subjects
- Anti-HIV Agents chemistry, Benzimidazoles chemistry, Drug Discovery, Drug Evaluation, Preclinical, Drug Resistance, Viral, HIV Infections virology, Humans, Macrophages virology, Monocytes virology, Virus Replication drug effects, Anti-HIV Agents pharmacology, Benzimidazoles pharmacology, HIV-1 drug effects, Prodrugs pharmacology, gag Gene Products, Human Immunodeficiency Virus drug effects
- Abstract
Although the effective use of highly active antiretroviral therapy results in the suppression of virus production in infected individuals, it does not eliminate the infection and low level virus production in cells harboring virus in sanctuary sites. Thus, the continued search for new antiretroviral agents with unique and different mechanisms of HIV inhibition remains critical, and compounds that can reduce the level of virus production from cells already infected with HIV, as opposed to preventing de novo infection, would be of great benefit. A mercaptobenzamide (MDH-1-38) and its prodrug (NS1040) are being developed as potential therapeutic compounds targeting the zinc finger of HIV nucleocapsid. In the presence of esterase enzymes, NS1040 is designed to be converted to MDH-1-38 which has antiviral activity. While we presume that NS1040 is rapidly converted to MDH-1-38 in all experiments, the two compounds were tested side-by-side to determine whether the presence of a prodrug affects the antiviral activity or mechanism of action. The two compounds were evaluated against a panel of HIV-1 clinical isolates in human PBMCs and monocyte-macrophages and yielded EC
50 values ranging from 0.7 to 13 μM with no toxicity up to 100 μM. MDH-1-38 and NS1040 remained equally active in human PBMCs in the presence of added serum proteins as well as against HIV-1 isolates resistant to reverse transcriptase, integrase or protease inhibitors. Cell-based and biochemical mechanism of antiviral action assays demonstrated MDH-1-38 and NS1040 were virucidal at concentrations of 15 and 50 μM, respectively. Cell to cell transmission of HIV in multiple passages was significantly reduced in CEM-SS and human PBMCs by reducing progeny virus infectivity at compound concentrations greater than 2 μM. The combination of either MDH-1-38 or NS1040 with other FDA-approved HIV drugs yielded additive to synergistic antiviral interactions with no evidence of antiviral antagonism or synergistic toxicity. Serial dose escalation was used in attempts to select for HIV strains resistant to MDH-1-38 and NS1040. Virus at several passages failed to replicate in cells treated at increased compound concentrations, which is consistent with the proposed mechanism of action of the virus inactivating compounds. Through 14 passages, resistance to the compounds has not been achieved. Most HIV inhibitors with mechanism of antiviral action targeting a viral protein would have selected for a drug resistant virus within 14 passages. These studies indicate that these NCp7-targeted compounds represent new potent anti-HIV drug candidates which could be effectively used in combination with all approved anti-HIV drugs., (Copyright © 2016. Published by Elsevier B.V.)- Published
- 2016
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10. Systematic evaluation of methyl ester bioisosteres in the context of developing alkenyldiarylmethanes (ADAMs) as non-nucleoside reverse transcriptase inhibitors (NNRTIs) for anti-HIV-1 chemotherapy.
- Author
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Hoshi A, Sakamoto T, Takayama J, Xuan M, Okazaki M, Hartman TL, Buckheit RW Jr, Pannecouque C, and Cushman M
- Subjects
- Anti-HIV Agents chemical synthesis, Anti-HIV Agents chemistry, Anti-HIV Agents pharmacology, Drug Stability, Esters chemistry, Esters pharmacology, Humans, Inhibitory Concentration 50, Methane chemistry, Methane pharmacology, Models, Molecular, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors chemistry, Reverse Transcriptase Inhibitors pharmacology, Esters chemical synthesis, HIV-1 drug effects, Methane chemical synthesis
- Abstract
The alkenyldiarylmethanes (ADAMs) are a class of non-nucleoside reverse transcriptase inhibitors (NNRTIs) targeting HIV-1. Four chemically and metabolically stabilized ADAMs incorporating N-methoxyimidoyl halide replacements of the methyl esters of the lead compound were previously reported. In this study, twenty-five new ADAMs were synthesized in order to investigate the biological consequences of installing nine different methyl ester bioisosteres at three different locations. Attempts to define a universal rank order of methyl ester bioisosteres and discover the 'best' one in terms of inhibitory activity versus HIV-1 reverse transcriptase (RT) led to the realization that the potencies are critically dependent on the surrounding structure at each location, and therefore the definition of universal rank order is impossible. This investigation produced several new non-nucleoside reverse transcriptase inhibitors in which all three of the three methyl esters of the lead compound were replaced by methyl ester bioisosteres, resulting in compounds that are more potent as HIV-1 RT inhibitors and antiviral agents than the lead compound itself and are expected to also be more metabolically stable than the lead compound., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
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- 2016
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11. Gaps in affiliation indexing in Scopus and PubMed.
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Schmidt CM, Cox R, Fial AV, Hartman TL, and Magee ML
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- Bibliometrics, Humans, Abstracting and Indexing methods, Databases, Bibliographic standards, Information Storage and Retrieval methods, PubMed standards
- Abstract
Objective: The authors sought to determine whether unexpected gaps existed in Scopus's author affiliation indexing of publications written by the University of Nebraska Medical Center or Nebraska Medicine (UNMC/NM) authors during 2014., Methods: First, we compared Scopus affiliation identifier search results to PubMed affiliation keyword search results. Then, we searched Scopus using affiliation keywords (UNMC, etc.) and compared the results to PubMed affiliation keyword and Scopus affiliation identifier searches., Results: We found that Scopus's records for approximately 7% of UNMC/NM authors' publications lacked appropriate UNMC/NM author affiliation identifiers, and many journals' publishers were supplying incomplete author affiliation information to PubMed., Conclusions: Institutions relying on Scopus to track their impact should determine whether Scopus's affiliation identifiers will, in fact, identify all articles published by their authors and investigators.
- Published
- 2016
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12. Creating Interactive Online Instruction: The McGoogan Library Experience.
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Hartman TL and Fial AV
- Subjects
- Academic Medical Centers, Humans, Nebraska, Organizational Case Studies, Program Development, Computer-Assisted Instruction, Libraries, Medical, User-Computer Interface
- Abstract
Online instruction is a hot topic at academic medical centers. Seizing the opportunity to join the online movement at the University of Nebraska Medical Center (UNMC), the McGoogan Library created an open access course made up of six learning modules. The modules addressed three issues: 1) supplementing one-shot library instruction, 2) offering opportunity for instruction when a librarian is not embedded in a course, and 3) showcasing the library as an online instruction supporter. This article discusses the planning process, technology used, how the modules were received, and how this initial project increased McGoogan Library's involvement in the UNMC online movement.
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- 2015
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13. Anti-HSV activity of serpin antithrombin III.
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Quenelle DC, Hartman TL, Buckheit RW, Prichard MN, and Lynn RG
- Abstract
Natural serine protease inhibitors (serpins) elicit sensing of a microbial cell intruder and activate an intrinsic cellular immune response in HIV and HCV infected cells. Here, we demonstrate in vitro inhibition of HSV with serpin antithrombin III (ATIII) early during infection pointing towards inhibition of an entry event. We also found reduction of mortality from 90% to 40% in an abrasion mice model demonstrating a strong reduction of infection in vivo . Our data also indicated that this treatment might be suitable for drug-resistant viruses since high inhibition of an acyclovir-resistant HSV-1 strain was found. Thus, an ATIII tropical treatment might be used for immunocompromised patients where prolonged treatment leads to drug resistant HSV-1 strains. Understanding how ATIII regulates HSV-1 infections may reveal new avenues for therapeutic interventions.
- Published
- 2014
14. The Continuing Evolution of HIV-1 Therapy: Identification and Development of Novel Antiretroviral Agents Targeting Viral and Cellular Targets.
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Hartman TL and Buckheit RW Jr
- Abstract
During the past three decades, over thirty-five anti-HIV-1 therapies have been developed for use in humans and the progression from monotherapeutic treatment regimens to today's highly active combination antiretroviral therapies has had a dramatic impact on disease progression in HIV-1-infected individuals. In spite of the success of AIDS therapies and the existence of inhibitors of HIV-1 reverse transcriptase, protease, entry and fusion, and integrase, HIV-1 therapies still have a variety of problems which require continued development efforts to improve efficacy and reduce toxicity, while making drugs that can be used throughout both the developed and developing world, in pediatric populations, and in pregnant women. Highly active antiretroviral therapies (HAARTs) have significantly delayed the progression to AIDS, and in the developed world HIV-1-infected individuals might be expected to live normal life spans while on lifelong therapies. However, the difficult treatment regimens, the presence of class-specific drug toxicities, and the emergence of drug-resistant virus isolates highlight the fact that improvements in our therapeutic regimens and the identification of new and novel viral and cellular targets for therapy are still necessary. Antiretroviral therapeutic strategies and targets continue to be explored, and the development of increasingly potent molecules within existing classes of drugs and the development of novel strategies are ongoing.
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- 2012
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15. Antiviral interactions of combinations of highly potent 2,4(1H,3H)-pyrimidinedione congeners and other anti-HIV agents.
- Author
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Hartman TL, Yang L, and Buckheit RW Jr
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- Anti-HIV Agents chemistry, Cell Line, Drug Synergism, Humans, Microbial Sensitivity Tests, Pyrimidinones chemistry, Anti-HIV Agents pharmacology, HIV-1 drug effects, HIV-2 drug effects, Pyrimidinones pharmacology
- Abstract
Structure-activity relationship evaluation of seventy-four 2,4(1H,3H)-pyrimidinedione derivatives identified seven lead compounds based on anti-HIV-1 potency, extended range of action to include HIV-2, virus entry inhibition, reverse transcriptase inhibition, and lack of cytotoxicity to human cells. The selected pyrimidinedione congeners are highly active inhibitors of HIV-1 with EC(50) values ranging from 0.6 to 2 nM in CEM-SS cells infected with laboratory derived viruses, 11-20 nM in fresh human PBMCs infected with subtype B (HT/92/599) virus, and 2-7 nM in PBMCs infected with the clinical subtype C (ZA/97/003) virus. Combination antiviral assays were performed using the laboratory adapted RF strain of HIV-1 in CEM-SS cells and with a clade B and C low passage clinical isolate in fresh human peripheral mononuclear cells and the compound interactions were analyzed using MacSynergy II. The seven pyrimidinedione compounds resulted in additive to synergistic interactions in combination with entry and fusion inhibitors, nonnucleoside and nucleoside reverse transcriptase inhibitors, and the protease inhibitors. No evidence of antagonistic antiviral activity or synergistic cytotoxicity was detected with the combinations of compounds tested. The dual mechanism of action of the pyrimidinediones resulting in inhibition of both virus entry and reverse transcription suggests excellent potential of these lead pyrimidinediones as candidates for combination therapy with other approved HIV inhibitors of varying mechanism of action., (Copyright © 2011. Published by Elsevier B.V.)
- Published
- 2011
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16. Inhibition of human immunodeficiency virus type 1 by triciribine involves the accessory protein nef.
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Ptak RG, Gentry BG, Hartman TL, Watson KM, Osterling MC, Buckheit RW Jr, Townsend LB, and Drach JC
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- Cell Line, Drug Resistance, Viral genetics, Genes, nef, HIV Reverse Transcriptase antagonists & inhibitors, HIV-1 genetics, HIV-2 drug effects, Humans, In Vitro Techniques, Microbial Sensitivity Tests, Point Mutation, Simian Immunodeficiency Virus drug effects, Virus Assembly drug effects, Virus Replication drug effects, Virus Replication genetics, Virus Replication physiology, nef Gene Products, Human Immunodeficiency Virus genetics, Anti-HIV Agents pharmacology, HIV-1 drug effects, HIV-1 physiology, Ribonucleosides pharmacology, nef Gene Products, Human Immunodeficiency Virus physiology
- Abstract
Triciribine (TCN) is a tricyclic nucleoside that inhibits human immunodeficiency virus type 1 (HIV-1) replication by a unique mechanism not involving the inhibition of enzymes directly involved in viral replication. This activity requires the phosphorylation of TCN to its 5' monophosphate by intracellular adenosine kinase. New testing with a panel of HIV and simian immunodeficiency virus isolates, including low-passage-number clinical isolates and selected subgroups of HIV-1, multidrug resistant HIV-1, and HIV-2, has demonstrated that TCN has broad antiretroviral activity. It was active in cell lines chronically infected with HIV-1 in which the provirus was integrated into chromosomal DNA, thereby indicating that TCN inhibits a late process in virus replication. The selection of TCN-resistant HIV-1 isolates resulted in up to a 750-fold increase in the level of resistance to the drug. DNA sequence analysis of highly resistant isolate HIV-1(H10) found five point mutations in the HIV-1 gene nef, resulting in five different amino acid changes. DNA sequencing of the other TCN-resistant isolates identified at least one and up to three of the same mutations observed in isolate HIV-1(H10). Transfer of the mutations from TCN-resistant isolate HIV-1(H10) to wild-type virus and subsequent viral growth experiments with increasing concentrations of TCN demonstrated resistance to the drug. We conclude that TCN is a late-phase inhibitor of HIV-1 replication and that mutations in nef are necessary and sufficient for TCN resistance.
- Published
- 2010
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17. Crystallographic study of a novel subnanomolar inhibitor provides insight on the binding interactions of alkenyldiarylmethanes with human immunodeficiency virus-1 reverse transcriptase.
- Author
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Cullen MD, Ho WC, Bauman JD, Das K, Arnold E, Hartman TL, Watson KM, Buckheit RW, Pannecouque C, De Clercq E, and Cushman M
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- Animals, Crystallography, X-Ray, HIV Reverse Transcriptase chemistry, HIV Reverse Transcriptase metabolism, HIV-1 drug effects, Humans, Hydrolysis, Inhibitory Concentration 50, Methane blood, Methane chemistry, Models, Molecular, Protein Binding, Protein Structure, Tertiary, Rats, Reverse Transcriptase Inhibitors blood, Reverse Transcriptase Inhibitors chemistry, HIV Reverse Transcriptase antagonists & inhibitors, HIV-1 enzymology, Methane metabolism, Methane pharmacology, Reverse Transcriptase Inhibitors metabolism, Reverse Transcriptase Inhibitors pharmacology
- Abstract
Two crystal structures have been solved for separate complexes of alkenyldiarylmethane (ADAM) nonnucleoside reverse transcriptase inhibitors (NNRTI) 3 and 4 with HIV-1 reverse transcriptase (RT). The structures reveal inhibitor binding is exclusively hydrophobic in nature and the shape of the inhibitor-bound NNRTI binding pocket is unique among other reported inhibitor-RT crystal structures. Primarily, ADAMs 3 and 4 protrude from a large gap in the back side of the binding pocket, placing portions of the inhibitors unusually close to the polymerase active site and allowing 3 to form a weak hydrogen bond with Lys223. The lack of additional stabilizing interactions, beyond the observed hydrophobic surface contacts, between 4 and RT is quite perplexing given the extreme potency of the compound (IC(50) = 1 nM). ADAM 4 was designed to be hydrolytically stable in blood plasma, and an investigation of its hydrolysis in rat plasma demonstrated it has a significantly prolonged half-life in comparison to ADAM lead compounds 1 and 2.
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- 2009
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18. Synthesis of alkenyldiarylmethanes (ADAMs) containing benzo[d]isoxazole and oxazolidin-2-one rings, a new series of potent non-nucleoside HIV-1 reverse transcriptase inhibitors.
- Author
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Deng BL, Zhao Y, Hartman TL, Watson K, Buckheit RW Jr, Pannecouque C, De Clercq E, and Cushman M
- Subjects
- Cell Line, HIV-1 drug effects, Humans, Isoxazoles chemistry, Isoxazoles pharmacology, Magnetic Resonance Spectroscopy, Oxazolidinones chemistry, Oxazolidinones pharmacology, Reverse Transcriptase Inhibitors chemistry, Spectrometry, Mass, Electrospray Ionization, Spectroscopy, Fourier Transform Infrared, Isoxazoles chemical synthesis, Oxazolidinones chemical synthesis, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors pharmacology
- Abstract
As a continuation of efforts to replace the metabolically labile methyl esters of lead alkenyldiarylmethanes (ADAMs) with stable bioisosteres, compounds bearing benzo[d]isoxazole and oxazolidine-2-one rings were designed and evaluated as a new series of potent HIV-1 non-nucleoside reverse transcriptase inhibitors with anti-HIV activity. All of the resulting ADAMs were found to inhibit HIV-1 RT with poly(rC) x oligo(dG) as the template primer. The most promising compound in this series was ADAM 3, with EC(50) values of 40 nM (vs HIV-1(RF)) and 20 nM (vs HIV-1(IIIB)). Compound 3 also inhibited HIV-1 reverse transcriptase with an IC(50) of 0.91 microM. ADAM 4 has an antiviral EC(50) of 0.6 microM in CEM-SS cells and a plasma half-life of 51.4 min.
- Published
- 2009
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19. Investigation of the alkenyldiarylmethane non-nucleoside reverse transcriptase inhibitors as potential cAMP phosphodiesterase-4B2 inhibitors.
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Cullen MD, Cheung YF, Houslay MD, Hartman TL, Watson KM, Buckheit RW Jr, Pannecouque C, De Clercq E, and Cushman M
- Subjects
- Alkenes chemical synthesis, Alkenes chemistry, Cell Line, Tumor, Cyclic Nucleotide Phosphodiesterases, Type 4, HIV Reverse Transcriptase antagonists & inhibitors, Humans, Inhibitory Concentration 50, Oxazoles chemical synthesis, Oxazoles chemistry, Oxazoles pharmacology, Phosphodiesterase Inhibitors chemical synthesis, Phosphodiesterase Inhibitors chemistry, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors chemistry, Structure-Activity Relationship, Alkenes pharmacology, Methane analogs & derivatives, Phosphodiesterase 4 Inhibitors, Phosphodiesterase Inhibitors pharmacology, Reverse Transcriptase Inhibitors pharmacology
- Abstract
The alkenyldiarylmethanes (ADAMs) are currently being investigated as non-nucleoside HIV-1 reverse transcriptase inhibitors (NNRTIs) of potential value in the treatment of HIV infection and AIDS. During the course of these studies, a number of ADAM analogues have been identified that protect HIV-infected cells from the cytopathic effects of the virus by an unknown, HIV-1 RT-independent mechanism. Since the phosphodiesterase 4 family is required for HIV infection, the effect of various ADAMs on the activity of PDE4B2 was investigated in an effort to determine if the ADAMs could possibly be targeting phosphodiesterases. Six compounds representative of the ADAM class were tested for inhibition of cAMP hydrolysis by PDE4B2 enzymatic activity. Four ADAMs were found to be weak inhibitors of PDE4B2 and two of them were inactive. The experimental results are consistent with an antiviral mechanism that does not include inhibition of PDE4 isoforms.
- Published
- 2008
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20. Inhibition of tubulin polymerization by select alkenyldiarylmethanes.
- Author
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Cullen MD, Sarkar T, Hamel E, Hartman TL, Watson KM, Buckheit RW Jr, Pannecouque C, De Clercq E, and Cushman M
- Subjects
- Cell Line, Tumor, Drug Screening Assays, Antitumor, HIV Reverse Transcriptase antagonists & inhibitors, Humans, Methane pharmacology, Reverse Transcriptase Inhibitors chemistry, Reverse Transcriptase Inhibitors pharmacology, Biopolymers chemistry, Methane analogs & derivatives, Tubulin chemistry
- Abstract
During studies on the alkenyldiarylmethane (ADAM) class of non-nucleoside reverse transcriptase inhibitors (NNRTIs), analogues were discovered that exhibit low micromolar and submicromolar cytotoxicities. Since the ADAMs are structurally related to the tubulin polymerization inhibitor CC-5079, a set of 14 ADAMs were tested for inhibition of tubulin polymerization in an attempt to identify the biological target responsible for their cytotoxicity. The results indicate that, overall, the ADAMs are poor inhibitors of tubulin polymerization. However, the two most cytotoxic compounds, 15 and 16, are in fact active as inhibitors of tubulin assembly with IC(50) values of 3.7+/-0.3 and 2.8+/-0.2 microM, respectively, and they both inhibit the binding of colchicine to tubulin. Both compounds were investigated for anticancer activity in the National Cancer Institute's panel of 60 human cancer cell lines, and both compounds consistently displayed submicromolar cytotoxicities with mean-graph midpoint (MGM) values of 0.31+/-0.08 and 0.47+/-0.09 microM, respectively.
- Published
- 2008
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21. Comparative evaluation of the inhibitory activities of a series of pyrimidinedione congeners that inhibit human immunodeficiency virus types 1 and 2.
- Author
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Buckheit RW Jr, Hartman TL, Watson KM, Chung SG, and Cho EH
- Subjects
- Cell Line, HIV Reverse Transcriptase antagonists & inhibitors, HIV-1 enzymology, HIV-1 pathogenicity, HIV-2 enzymology, HIV-2 pathogenicity, HeLa Cells, Humans, Microbial Sensitivity Tests, Reverse Transcriptase Inhibitors pharmacology, Structure-Activity Relationship, Anti-HIV Agents pharmacology, HIV-1 drug effects, HIV-2 drug effects, Pyridones chemistry, Pyridones pharmacology
- Abstract
Seventy-three analogs of SJ-3366 (1-(3-cyclopenten-1-ylmethyl)-5-ethyl-6-(3,5-dimethylbenzoyl)-2,4(1H,3H)-pyrimidinedione) were synthesized and comparatively evaluated for their ability to inhibit the replication of human immunodeficiency virus type 1 (HIV-1) and HIV-2 and for their ability to suppress virus entry and reverse transcription. These studies were performed to identify inhibitors with activity greater than that of the current lead molecule (SJ-3366) and to utilize structure-activity relationships (SAR) to define the chemical features of the pyrimidinedione congeners responsible for their efficacy, toxicity, and dual mechanism of action against HIV. The results of our SAR evaluations have demonstrated that the addition of the homocyclic moiety at the N-1 of the pyrimidinedione results in acquisition of the ability to inhibit virus entry and extends the range of action of the compounds to include HIV-2. In addition, the results demonstrate that analogs with a methyl linker between the homocyclic substitution and the N-1 of the pyrimidinedione had a greater number of highly active molecules than those analogs possessing ethyl linkers. Six molecules were identified with activity equivalent to or greater than that of SJ-3366, and five additional molecules with highly potent inhibition of reverse transcriptase and virus entry and possessing high efficacy against both HIV-1 and HIV-2 were identified. Six molecules exhibited significant inhibition of viruses with the highly problematic nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance engendering amino acid change K103N in the reverse transcriptase. These evaluations indicate that a new class of NNRTIs has been identified and that these NNRTIs possess highly potent inhibition of HIV-1 with an extended range of action, which now includes HIV-2.
- Published
- 2008
- Full Text
- View/download PDF
22. Synthesis and biological evaluation of alkenyldiarylmethane HIV-1 non-nucleoside reverse transcriptase inhibitors that possess increased hydrolytic stability.
- Author
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Cullen MD, Deng BL, Hartman TL, Watson KM, Buckheit RW Jr, Pannecouque C, Clercq ED, and Cushman M
- Subjects
- Alkenes pharmacology, Alkenes toxicity, Animals, Anti-HIV Agents pharmacology, Anti-HIV Agents toxicity, Benzoates pharmacology, Benzoates toxicity, Cytopathogenic Effect, Viral drug effects, Drug Resistance, Viral, HIV Reverse Transcriptase metabolism, HIV-1 enzymology, HIV-1 genetics, Hydrolysis, Mutation, Nitriles chemical synthesis, Nitriles pharmacology, Nitriles toxicity, Oxadiazoles chemical synthesis, Oxadiazoles pharmacology, Oxadiazoles toxicity, Oxazoles chemical synthesis, Oxazoles pharmacology, Oxazoles toxicity, Rats, Reverse Transcriptase Inhibitors pharmacology, Reverse Transcriptase Inhibitors toxicity, Stereoisomerism, Structure-Activity Relationship, Tetrazoles chemical synthesis, Tetrazoles pharmacology, Tetrazoles toxicity, Alkenes chemical synthesis, Anti-HIV Agents chemical synthesis, Benzoates chemical synthesis, HIV Reverse Transcriptase chemistry, HIV-1 drug effects, Reverse Transcriptase Inhibitors chemical synthesis
- Abstract
Non-nucleoside inhibitors of HIV reverse transcriptase (NNRTIs), albeit not the mainstays of HIV/AIDS treatment, have become increasingly important in highly active antiretroviral therapy (HAART) due to their unique mechanism of action. Several years ago our group identified the alkenyldiarylmethanes (ADAMs) as a potent and novel class of NNRTIs; however, the most active compounds were found to be metabolically unstable. Subsequent work has led to the synthesis of 33 analogues, with improved metabolic profiles, through the replacement of labile esters with various heterocycles, nitriles, and thioesters. As a result, a number of hydrolytically stable NNRTIs were identified with anti-HIV activity in the nanomolar concentration range. Furthermore, an improved pharmacophore model has been developed based on the new ADAM series, in which a salicylic acid-derived aryl ring is oriented cis to the side chain and the aryl ring that is trans to the side chain contains a hydrogen bond acceptor site within the plane of the ring.
- Published
- 2007
- Full Text
- View/download PDF
23. Synthesis and anti-HIV activity of new metabolically stable alkenyldiarylmethane non-nucleoside reverse transcriptase inhibitors incorporating N-methoxy imidoyl halide and 1,2,4-oxadiazole systems.
- Author
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Sakamoto T, Cullen MD, Hartman TL, Watson KM, Buckheit RW, Pannecouque C, De Clercq E, and Cushman M
- Subjects
- Allosteric Regulation, Anti-HIV Agents chemistry, Cell Line, Humans, Magnetic Resonance Spectroscopy, Reverse Transcriptase Inhibitors chemistry, Spectrometry, Mass, Electrospray Ionization, Static Electricity, Anti-HIV Agents chemical synthesis, Anti-HIV Agents pharmacology, Halogens chemistry, Imides chemistry, Oxadiazoles chemistry, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors pharmacology
- Abstract
The alkenyldiarylmethanes (ADAMs) are a unique class of non-nucleoside reverse transcriptase inhibitors (NNRTIs) that are capable of inhibiting HIV-1 reverse transcriptase (RT) through an allosteric mechanism. However, the potential usefulness of the ADAMs is limited by the presence of metabolically labile methyl ester moieties that are hydrolyzed by nonspecific esterases present in blood plasma, resulting in the formation of the inactive carboxylic acid metabolites. Therefore, to discover metabolically stable ADAMs, the design and synthesis of a new class of ADAMs with N-methoxy imidoyl halide and 1,2,4-oxadiazole systems were attempted. The resulting new ADAM 6 displayed enhanced metabolic stability in rat plasma (t1/2 = 61 h) along with the ability to inhibit HIV-1 reverse transcriptase and the cytopathic effect of HIV-1RF and HIV-1IIIB at submicromolar concentrations.
- Published
- 2007
- Full Text
- View/download PDF
24. Navigating the US health care system: a video guide for immigrant and diverse populations.
- Author
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Bobal AM, Brown HL, Hartman TL, Magee M, and Schmidt CM
- Subjects
- Child, Child, Preschool, Humans, Language, Libraries, Medical, Nebraska, Video Recording methods, Audiovisual Aids, Cultural Diversity, Emigration and Immigration, Health Education methods, Health Services Accessibility
- Published
- 2007
- Full Text
- View/download PDF
25. Preceptorship rurality does not affect medical students' shelf exam scores.
- Author
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Lacy NL, Geske JA, Goodman BJ, Hartman TL, and Paulman PM
- Subjects
- Clinical Competence standards, Humans, Urban Population, Educational Measurement, Preceptorship, Rural Population, Students, Medical
- Abstract
Objective: This study's objective was to determine whether junior medical students' end-of-rotation shelf exam scores varied by the preceptorship county's rurality., Methods: Student learning during rural preceptorship experiences, 1999 to 2005, was assessed using the students' scores on the National Board of Medical Examiners family medicine subject examination. Rurality was measured using both population density and the rural-urban continuum (RUC) codes., Results: Exam scores were collected between January 1999 and May 2005 for 734 students. Mean scores did not vary significantly by rurality, although they did vary significantly by semester. Test scores of students in rural locations were not statistically significantly different from those of students in urban preceptorships., Conclusions: Students assigned to preceptorships in rural locations scored at the same levels as students in urban preceptorships. The finding that there were no differences in medical students' exam scores based on the rurality of their family medicine preceptorship site indicates a substantial degree of educational equivalency between urban and rural preceptorships.
- Published
- 2007
26. The structure-activity relationships of 2,4(1H,3H)-pyrimidinedione derivatives as potent HIV type 1 and type 2 inhibitors.
- Author
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Buckheit RW Jr, Hartman TL, Watson KM, Kwon HS, Lee SH, Lee JW, Kang DW, Chung SG, and Cho EH
- Subjects
- Anti-HIV Agents chemical synthesis, Anti-HIV Agents chemistry, Cell Line, Cell Survival drug effects, Dose-Response Relationship, Drug, Humans, Microbial Sensitivity Tests, Molecular Structure, Stereoisomerism, Structure-Activity Relationship, Uracil chemical synthesis, Uracil chemistry, Uracil pharmacology, Anti-HIV Agents pharmacology, HIV-1 drug effects, HIV-2 drug effects, Uracil analogs & derivatives
- Abstract
Since the discovery of the 2,4 (1H,3H)-pyrimidinediones as potent non-nucleoside inhibitors of the HIV-1 reverse transcriptase (RT) this class of compounds has yielded a number of N-1 acyclic substituted pyrimidinediones with substantial antiviral activity, which is highly dependent upon their molecular fit into the binding pocket common to this inhibitory class. We have specifically examined the structure activity relationships of compounds with chemical modification made by substituting homocyclic rather than acyclic moieties at N-1 of the pyrimidinedione. Seventy-four compounds were synthesized and evaluated for antiviral activity against HIV-1 and HIV-2. The homocyclic modifications resulted in compounds with significant activity against both HIV-1 and HIV-2, suggesting these compounds represent a new class of non-nucleoside RT inhibitors. The structure-activity relationship (SAR) evaluations indicated that cyclopropyl, phenyl and 1- or 3-cyclopenten-1-yl substitutions at the N-1 of the pyrimidinedione, the addition of a methyl linker between the cyclic moiety and the N-1 and the addition of a benzoyl group at the C-6 of the pyrimidinedione had the greatest contribution to antiviral activity. Five pyrimidinedione analogues with therapeutic indexes (TIs) > 450,000 and a specific analogue (1-cyclopropylmethyl-5-isopropyl-6-(3,5-dimethylbenzoyl)-2,4(1H,3H)-pyrimidinedione), which exhibited a TI of > 2,000,000, were identified. None of the analogues were cytotoxic to target cells at the highest in vitro test concentration, which is the upper limit of compound solubility of the analogues in aqueous solution. Thus, we have identified a series of pyrimidinediones with substantially improved antiviral efficacy and range of action and with significantly reduced cellular cytotoxicity.
- Published
- 2007
- Full Text
- View/download PDF
27. Carrageenan/MIV-150 (PC-815), a combination microbicide.
- Author
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Fernández-Romero JA, Thorn M, Turville SG, Titchen K, Sudol K, Li J, Miller T, Robbiani M, Maguire RA, Buckheit RW Jr, Hartman TL, and Phillips DM
- Subjects
- Anti-Infective Agents administration & dosage, Anti-Infective Agents therapeutic use, Carrageenan administration & dosage, Carrageenan therapeutic use, Drug Therapy, Combination, HIV Infections prevention & control, HIV-1 drug effects, HIV-2 drug effects, Humans, Male, Microbial Sensitivity Tests, Pyridines administration & dosage, Pyridines therapeutic use, Reverse Transcriptase Inhibitors administration & dosage, Reverse Transcriptase Inhibitors therapeutic use, Semen virology, Urea administration & dosage, Urea pharmacology, Urea therapeutic use, Anti-Infective Agents pharmacology, Carrageenan pharmacology, Chondrus, Phytotherapy, Pyridines pharmacology, Reverse Transcriptase Inhibitors pharmacology, Urea analogs & derivatives
- Abstract
Objective: The objective of this article is to study the effect of PC-815, a novel combination microbicide containing carrageenan and the nonnucleoside reverse transcriptase inhibitor (NNRTI) MIV-150, in blocking HIV-1 and HIV-2 infections in vitro as compared with Carraguard alone., Goal: The goal of this study was to develop a combination microbicide that is more efficacious than Carraguard against HIV-1 and HIV-2., Study Design: The microtiter syncytial assay was used to evaluate: 1) the antiviral and virucidal activity of MIV-150 against HIV-1MN; 2) the additive effect of MIV-150 when combined with carrageenan; and 3) a possible interference of seminal fluid in the antiviral activity of these compounds., Results: MIV-150 effectively inactivated free virus. Combination of MIV-150 and Carraguard demonstrated an additive antiviral effect. Seminal fluid had no effect on the antiviral activity of MIV-150 or Carraguard. The average concentration that blocks 50% of infection (EC50) for PC-815 was approximately 10 times stronger than Carraguard for the different clinical isolates used in the study., Conclusion: Theoretically, PC-815 is likely to be a more efficacious microbicide than Carraguard.
- Published
- 2007
- Full Text
- View/download PDF
28. Replacement of the metabolically labile methyl esters in the alkenyldiarylmethane series of non-nucleoside reverse transcriptase inhibitors with isoxazolone, isoxazole, oxazolone, or cyano substituents.
- Author
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Deng BL, Hartman TL, Buckheit RW Jr, Pannecouque C, De Clercq E, and Cushman M
- Subjects
- Animals, Anti-HIV Agents chemistry, Anti-HIV Agents pharmacology, Cell Line, Drug Design, Humans, In Vitro Techniques, Microbial Sensitivity Tests, Molecular Structure, Rats, Reverse Transcriptase Inhibitors chemistry, Reverse Transcriptase Inhibitors pharmacology, Stereoisomerism, Structure-Activity Relationship, Anti-HIV Agents chemical synthesis, Cyanides chemistry, Esters chemistry, Isoxazoles chemistry, Oxazolone chemistry, Reverse Transcriptase Inhibitors chemical synthesis
- Abstract
The alkenyldiarylmethanes (ADAMs) are a unique class of non-nucleoside reverse transcriptase inhibitors that have potential value in the treatment of HIV/AIDS. However, the potential usefulness of the ADAMs is limited by the presence of metabolically labile methyl ester moieties. A series of novel ADAMs were therefore designed and synthesized in order to replace the metabolically labile methyl ester moieties of the existing ADAM lead compounds with hydrolytically stable, fused isoxazolone, isoxazole, oxazolone, or cyano substituents on the aromatic rings. The methyl ester and methoxy substituents on both of the aromatic rings in the parent compound 1 were successfully replaced with metabolically stable moieties with retention of anti-HIV activity and a general decrease in cytotoxicity.
- Published
- 2006
- Full Text
- View/download PDF
29. Synthesis and anti-HIV activity of new alkenyldiarylmethane (ADAM) non-nucleoside reverse transcriptase inhibitors (NNRTIs) incorporating benzoxazolone and benzisoxazole rings.
- Author
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Deng BL, Cullen MD, Zhou Z, Hartman TL, Buckheit RW Jr, Pannecouque C, De Clercq E, Fanwick PE, and Cushman M
- Subjects
- Animals, Anti-HIV Agents chemistry, Benzoxazoles chemistry, Cell Line, Crystallography, X-Ray, Drug Design, HIV-1 drug effects, HIV-2 drug effects, Humans, In Vitro Techniques, Isoxazoles chemistry, Methane analogs & derivatives, Microbial Sensitivity Tests, Models, Molecular, Molecular Structure, Protein Conformation, Rats, Reverse Transcriptase Inhibitors chemistry, Structure-Activity Relationship, Anti-HIV Agents chemical synthesis, Anti-HIV Agents pharmacology, Methane chemical synthesis, Methane pharmacology, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors pharmacology
- Abstract
The HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) constitute a large and structurally diverse set of compounds, several of which are currently used in the treatment of AIDS. A series of novel alkenyldiarylmethanes (ADAMs) were designed and synthesized as part of an ongoing investigation to replace the metabolically labile methyl ester moieties found in the ADAM pharmacophore with stable modifications that retain the potent anti-HIV activity of the parent compounds. Unsurprisingly, the rat plasma half-lives of the new ADAMs were not improved when compared to the parent compounds, but all of the synthesized ADAMs inhibited the cytopathic effect of HIV-1 in cell culture. The most potent compound identified was (E)-5-[1-(3,7-dimethyl-2-oxo-2,3-dihydro-benzoxazol-5-yl)-5-methoxycarbonyl-pent-1-enyl]-2-methoxy-3-methylbenzoic acid methyl ester (7), which inhibited the cytopathic effects of both HIV-1(RF) and HIV-1(IIIB) strains in cell cultures with EC50 values of 30 and 90 nM, respectively, and inhibited HIV-1 reverse transcriptase with an IC50 of 20 nM.
- Published
- 2006
- Full Text
- View/download PDF
30. Synthesis, anti-HIV activity, and metabolic stability of new alkenyldiarylmethane HIV-1 non-nucleoside reverse transcriptase inhibitors.
- Author
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Deng BL, Hartman TL, Buckheit RW Jr, Pannecouque C, De Clercq E, Fanwick PE, and Cushman M
- Subjects
- Animals, Anti-HIV Agents chemistry, Anti-HIV Agents pharmacology, Cell Line, Crystallography, X-Ray, Cytopathogenic Effect, Viral, HIV-1 enzymology, HIV-1 pathogenicity, Methane blood, Methane pharmacology, Rats, Reverse Transcriptase Inhibitors blood, Reverse Transcriptase Inhibitors pharmacology, Stereoisomerism, Structure-Activity Relationship, Anti-HIV Agents chemical synthesis, HIV-1 drug effects, Methane analogs & derivatives, Methane chemical synthesis, Reverse Transcriptase Inhibitors chemical synthesis
- Abstract
Non-nucleoside inhibitors of HIV-1 reverse transcriptase (NNRTIs) are part of the combination therapy currently used to treat HIV infection. Based on analogy with known HIV-1 NNRT inhibitors, 18 novel alkenyldiarylmethanes (ADAMs) containing 5-chloro-2-methoxyphenyl, 3-cyanophenyl, or 3-fluoro-5-trifluoromethylphenyl groups were synthesized and evaluated as HIV inhibitors. Their stabilities in rat plasma have also been investigated. Although introducing 5-chloro-2-methoxyphenyl or 3-fluoro-5-trifluoromethylphenyl groups into alkenyldiarylmethanes does not maintain the antiviral potency, the structural modification of alkenyldiarylmethanes with a 3-cyanophenyl substituent can be made without a large decrease in activity. The oxazolidinonyl group was introduced into the alkenyldiarylmethane framework and found to confer enhanced metabolic stability in rat plasma.
- Published
- 2005
- Full Text
- View/download PDF
31. The effect of preceptorship rurality on students' self-perceived clinical competency.
- Author
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Lacy NL, Paulman PM, and Hartman TL
- Subjects
- Educational Measurement, Female, Humans, Male, Nebraska, Rural Population, Sex Factors, Surveys and Questionnaires, Clinical Competence, Family Practice education, Preceptorship, Self-Assessment, Students, Medical
- Abstract
Objective: This study's objective was to determine whether students' learning experiences, as measured by the improvement in students' perceived competence in several clinical areas, varied by the preceptorship county's rurality., Methods: Rural preceptorship experiences from 1990 to 2003 were assessed using pre- and post-preceptorship questionnaires regarding students' perceived levels of competence. Questionnaires addressed basic clinical skills, common diagnoses, and advanced clinical skills. Rurality was measured both as population density and using the Rural-Urban Continuum (RUC) codes., Results: Primary analysis was completed using 1,037 sets of questionnaires; 231 questionnaires were unsuitable for analysis due to missing information. Mean perceived competency improved for all items. Students in rural locations, regardless of operationalization, had no statistically significant differences from students in urban locations in perceptions of their clinical skill or comfort with basic diagnoses. Individual item analyses revealed a gendered pattern. Women improved more than men on the technical skills; men improved more on women's health and psychosocial items., Conclusions: There were no differences in medical students' perceived competence based on the rurality of their family medicine preceptorship site. The preceptorship experience provides both women and men with a variety of experiences that lead to increased confidence in areas where they were least confident prior to the preceptorship.
- Published
- 2005
32. Synthesis of substituted diarylmethylenepiperidines (DAMPs), a novel class of anti-HIV agents.
- Author
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Xu G, Kannan A, Hartman TL, Wargo H, Watson K, Turpin JA, Buckheit RW Jr, Johnson AA, Pommier Y, and Cushman M
- Subjects
- HIV-1 drug effects, HIV-1 pathogenicity, Humans, Inhibitory Concentration 50, Structure-Activity Relationship, Time Factors, Transcription, Genetic drug effects, Tumor Necrosis Factor-alpha pharmacology, Virus Integration drug effects, Anti-HIV Agents chemical synthesis, Piperidines chemical synthesis
- Abstract
Substituted diarylmethylenepiperidines (DAMPs) were synthesized as conformationally restricted analogues of the alkenyldiarylmethane (ADAM) class of non-nucleoside reverse transcriptase inhibitors (NNRTIs). Although, like the ADAMs, the DAMPs were found to inhibit the cytopathic effect of HIV-1(RF) in CEM-SS cells, they were completely inactive as inhibitors of HIV-1 reverse transcriptase. The DAMPs were assessed for inhibition of HIV attachment and fusion. DAMP was active in both assays with IC(50) values of 26.5 microM (TI 3.8) and 12.1 microM (TI: >8), respectively. DAMP also inhibited HIV fusion with an IC(50 )12.8 microM (TI: >6), but not virus attachment. However, attempts to verify inhibition of virus attachment and fusion as antiviral targets using time-of-addition experiments failed to confirm these observations, and instead identified an antiviral target occurring after completion of reverse transcription. DAMPs, and were found to inhibit virus replication if added 8 h post virus exposure, and DAMP was equipotent at inhibition of virus replication if added 24 h after virus addition. DAMPs, and did not inhibit virus replication in TNF-alpha induced latently infected U1 cells, a model for post-integrative antiviral targets. When tested in both 3' end-processing and strand-transfer assays in the presence of HIV-1 integrase, none of the DAMPs showed any inhibitory activity, indicating that HIV-1 integrase is not involved in the mechanism of the antiviral action. Thus, the DAMPs are novel conformationally restricted analogues of the previously published ADAM series with an unidentified antiviral target bounded by the completion of reverse transcription and virus integration.
- Published
- 2002
- Full Text
- View/download PDF
33. Benzamide-based thiolcarbamates: a new class of HIV-1 NCp7 inhibitors.
- Author
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Goel A, Mazur SJ, Fattah RJ, Hartman TL, Turpin JA, Huang M, Rice WG, Appella E, and Inman JK
- Subjects
- Anti-HIV Agents pharmacology, Cell Survival drug effects, Cells, Cultured, HIV Infections drug therapy, HIV-1 physiology, Humans, Monocytes drug effects, Structure-Activity Relationship, Thiocarbamates pharmacology, Tumor Necrosis Factor-alpha pharmacology, Zinc Fingers, gag Gene Products, Human Immunodeficiency Virus, Anti-HIV Agents chemical synthesis, Benzamides chemistry, Capsid antagonists & inhibitors, Capsid Proteins, Gene Products, gag antagonists & inhibitors, HIV-1 drug effects, Thiocarbamates chemical synthesis, Viral Proteins
- Abstract
The HIV-1 nucleocapsid protein NCp7, which contains two highly conserved zinc fingers, is being used as a novel target for AIDS therapy due to its pivotal role in viral replication and its mutationally intolerant nature. Herein we report a new class of NCp7 inhibitors that possess good antiviral activity with low cellular toxicity.
- Published
- 2002
- Full Text
- View/download PDF
34. Synthesis of alkenyldiarylmethane (ADAM) non-nucleoside HIV-1 reverse transcriptase inhibitors with non-identical aromatic rings.
- Author
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Xu G, Hartman TL, Wargo H, Turpin JA, Buckheit RW, and Cushman M
- Subjects
- Cells, Cultured, Drug Evaluation, Preclinical methods, Humans, Hydrocarbons, Aromatic chemistry, Inhibitory Concentration 50, Structure-Activity Relationship, Biochemistry methods, HIV Reverse Transcriptase antagonists & inhibitors, Reverse Transcriptase Inhibitors chemistry, Reverse Transcriptase Inhibitors pharmacology
- Abstract
The existing methods for the synthesis of alkenyldiarylmethane (ADAM) non-nucleoside reverse transcriptase inhibitors proceed from symmetrical benzophenones and therefore result in products with identical aromatic rings. New methods have therefore been devised for the preparation of stereochemically defined ADAMs with non-identical aromatic rings. The new routes rely on palladium-catalyzed reactions, including Sonogashira, Suzuki, Stille, and hydroarylation methodology. Several of the new ADAMs inhibited the cytopathic effect of HIV-1 in cell culture and HIV-1 reverse transcriptase at submicromolar concentrations.
- Published
- 2002
- Full Text
- View/download PDF
35. The biological effects of structural variation at the meta position of the aromatic rings and at the end of the alkenyl chain in the alkenyldiarylmethane series of non-nucleoside reverse transcriptase inhibitors.
- Author
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Xu G, Micklatcher M, Silvestri MA, Hartman TL, Burrier J, Osterling MC, Wargo H, Turpin JA, Buckheit RW Jr, and Cushman M
- Subjects
- Alkenes chemistry, Alkenes pharmacology, Benzene Derivatives chemistry, Benzene Derivatives pharmacology, Cell Line, Cytopathogenic Effect, Viral, Drug Resistance, Multiple, Drug Resistance, Viral, HIV Reverse Transcriptase genetics, HIV-1 drug effects, HIV-1 isolation & purification, Humans, In Vitro Techniques, Leukocytes, Mononuclear drug effects, Leukocytes, Mononuclear enzymology, Leukocytes, Mononuclear virology, Models, Molecular, Monocytes drug effects, Monocytes enzymology, Monocytes virology, Mutagenesis, Site-Directed, Reverse Transcriptase Inhibitors chemistry, Reverse Transcriptase Inhibitors pharmacology, Structure-Activity Relationship, Virus Replication, Alkenes chemical synthesis, Benzene Derivatives chemical synthesis, HIV Reverse Transcriptase antagonists & inhibitors, Reverse Transcriptase Inhibitors chemical synthesis
- Abstract
In an effort to elucidate a set of structure-activity relationships in the alkenyldiarylmethane (ADAM) series of non-nucleoside reverse transcriptase inhibitors, a number of modifications were made at two locations: (1) the meta positions of the two aromatic rings and (2) the end of the alkenyl chain. Forty-two new ADAMs were synthesized and evaluated for inhibition of the cytopathic effect of HIV-1(RF) in CEM-SS cell culture and for inhibition of HIV-1 reverse transcriptase. The size of the aromatic substituents was found to affect anti-HIV activity, with optimal activity appearing with Cl, CH(3), and Br substituents and with diminished activity occurring with smaller (H and F) or larger (I and CF(3)) substituents. The substituents at the end of the alkenyl chain were also found to influence the antiviral activity, with maximal activity associated with methyl or ethyl ester groups and with diminished activity resulting from substitution with higher esters, amides, sulfides, sulfoxides, sulfones, thioesters, acetals, ketones, carbamates, ureas, and thioureas. Twelve of the new ADAMs displayed submicromolar EC(50) values for inhibition of the cytopathic effect of HIV-1(RF) in CEM-SS cells. Selected ADAMs, 19 and 21, were compared to previously published ADAMs 15 and 17 for antiviral efficacy and activity against the HIV-1 reverse transcriptase enzyme. All four ADAMs were found to inhibit HIV-1 reverse transcriptase enzyme activity, to inhibit the replication of a variety of HIV-1 clinical isolates representing syncytium-inducing, nonsyncytium-inducing, and subtype representative isolates, and to inhibit HIV-1 replication in monocytes. Subsequent assessment against a panel of site-directed reverse transcriptase mutants in NL4-3 demonstrated no effect of the K103N mutation on antiviral efficacy and a slight enhancement (6- to 11-fold) in sensitivity to AZT-resistant viruses. Additionally, ADAMs 19 (44-fold) and 21 (29-fold) were more effective against the A98G mutation (found in association with nevirapine resistance in vitro), and ADAM 21 was 5-fold and 2-fold more potent against the Y181C inactivation mutation than the previously reported ADAMs 15 and 17, respectively. All four ADAMs were tested for efficacy against a multidrug-resistant virus derived from a highly experienced patient expressing resistance to the reverse transcriptase enzyme inhibitors AZT, ddI, 3TC, d4T, foscarnet, and nevirapine, as well as the protease inhibitors indinavir, saquinavir, and nelfinavir. ADAM 21 was 2-fold more potent than ADAM 15 and 6-fold more potent than ADAMs 17 and 19 at preventing virus replication. Thus, we have identified a novel series of reverse transcriptase inhibitors with a favorable profile of antiviral activity against the primary mutation involved in clinical failure of non-nucleoside reverse transcriptase inhibitors, K103N, and that retain activity against a multidrug-resistant virus.
- Published
- 2001
- Full Text
- View/download PDF
36. Successful use of cuffed central venous hemodialysis catheters inserted percutaneously.
- Author
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Swartz RD, Messana JM, Boyer CJ, Lunde NM, Weitzel WF, and Hartman TL
- Subjects
- Equipment Failure, Humans, Infections etiology, Infections microbiology, Renal Dialysis instrumentation, Catheterization, Central Venous instrumentation, Catheterization, Central Venous methods, Catheters, Indwelling adverse effects, Renal Dialysis methods
- Abstract
Although endogenous fistulae and grafts are preferred for permanent hemodialysis access, central venous catheters are often required for varying intervals when creating permanent access is not feasible. The prospective experience with 118 catheters in over a 3.5-yr period is reported; 93 (79%) were placed by percutaneous techniques, and 25 (21%) were placed by operative techniques. Seventy seven catheters (65%) were placed in the subclavian vein, 36 (31%) were placed in the internal jugular vein (usually right side), and 5 (4%) were placed in the femoral vein. Early postplacement complications were infrequent. Catheter function at last local follow-up ranged from several days to nearly 2 yr, averaging approximately 3 mo, even though many patients returned to their referring centers with a functioning catheter after only a short follow-up. Actuarial survival for percutaneously placed catheters was approximately 60% at 6 mo and 30% at 12 mo. Catheter failure occurred in 36% of cases, equally divided between malfunction (thrombosis refractory to fibrinolysis, extrusion, kinking, or related event) and infection with septicemia requiring removal. Such failure was not more frequent after percutaneous placement than after operative placement. Failure due to mechanical malfunction, but not that due to infection, tended to be less frequent among catheters placed in the internal jugular vein than among catheters placed in the subclavian vein. Finally, infection with septicemia involved 22% of all catheters and occurred at an average cumulated rate of approximately one infection per patient-year. Coagulase-positive staphylococcus was the most common organism isolated.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1994
- Full Text
- View/download PDF
37. Behavioral pharmacology of NPC 17742, a competitive N-methyl-D-aspartate (NMDA) antagonist.
- Author
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Willetts J, Clissold DB, Hartman TL, Brandsgaard RR, Hamilton GS, and Ferkany JW
- Subjects
- 2-Amino-5-phosphonovalerate analogs & derivatives, 2-Amino-5-phosphonovalerate pharmacology, Animals, Binding, Competitive, Dose-Response Relationship, Drug, Isoquinolines pharmacology, Male, Mice, Pipecolic Acids pharmacology, Rats, Rats, Sprague-Dawley, Receptors, N-Methyl-D-Aspartate metabolism, Amino Acids pharmacology, Behavior, Animal drug effects, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors
- Abstract
The behavioral effects of the competitive N-methyl-D-aspartate (NMDA) antagonist 2R,4R,5S-2-amino-4,5-(1,2-cyclohexyl)-7-phosphonoheptanoate (NPC 17742) were compared with those of its parent compound, 2-amino-4,5-(1,2-cyclohexyl)-7-phosphonoheptanoate (NPC 12626), and other reference agents in a variety of operant-based tasks in rodents. In mice trained to lever press under a fixed-ratio (FR) 20 reinforcement schedule, NPC 17742 was 6.2 times more potent than NPC 12626 and equipotent with the competitive NMDA antagonist [E]-2-amino-4-methyl-5-phosphono-3-penteneoic acid (CGP 37849) in reducing rates of responding. NPC 17742 was also 3.5 and 4.5 times more potent than [+-]cis-4-phosphonomethyl-2-piperidine carboxylate (CGS 19755) and [+-] 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonate (CPP), respectively, and half as potent as 3SR, 4aRS, 6SR, 8aRS-6-(phosphonomethyl)-1,2,3,4,4a,5,6,7,8,8a- decahydroisoquinoline-3-carboxylate (LY 274614) in this paradigm. In rats trained to discriminate 4.0 mg/kg NPC 17742 from saline, NPC 17742 was 5.7 times more potent than NPC 12626 in substituting for NPC 17742. CGS 19755 also substituted for NPC 17742, but a maximum of only 50% NPC 17742 lever responding was observed after LY 274614 administration. In rats trained to lever press in a modified Geller-Seifter procedure, NPC 17742 and NPC 12626, like the benzodiazepine chlordiazepoxide, increased rates of punished responding. Neither tolerance nor sensitization to the anti-punishment effects were observed upon administration of NPC 17742 for 5 consecutive days. The results are consistent with NPC 17742 being a potent, systemically active compound whose behavioral effects are mediated through interaction with the NMDA receptor.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1993
38. Sulfonamide sensitivity determinations of hemolytic streptococci isolated from patients before and after treatment with sulfadiazine.
- Author
-
HARTMAN TL
- Subjects
- Humans, Sulfanilamide, Streptococcal Infections, Streptococcus, Sulfadiazine pharmacology, Sulfanilamides, Sulfonamides chemistry
- Published
- 1946
39. SULFADIAZINE RESISTANT STREPTOCOCCAL INFECTIONS IN A CIVILIAN COMMUNITY.
- Author
-
Johnson RD and Hartman TL
- Subjects
- Humans, Infections, Streptococcal Infections, Streptococcus, Sulfadiazine therapy
- Published
- 1947
- Full Text
- View/download PDF
40. Methyl chloride intoxication; report of two cases; one complicating pregnancy.
- Author
-
Hartman TL, Wacker W, and Roll RM
- Subjects
- Humans, Pregnancy, Methyl Chloride poisoning, Poisoning
- Published
- 1955
- Full Text
- View/download PDF
41. The problem of sulfonamide-resistant hemolytic streptococci.
- Author
-
Hartman TL and Weinstein L
- Subjects
- Humans, Sulfanilamide, Sulfanilamides, Streptococcal Infections, Streptococcus, Sulfonamides
- Published
- 1948
- Full Text
- View/download PDF
42. Drug sensitivity of hemolytic streptococci isolated from cases of scarlet fever treated with penicillin.
- Author
-
HARTMAN TL and WEINSTEIN L
- Subjects
- Humans, Drug Tolerance, Estrogens, Penicillins pharmacology, Scarlet Fever, Streptococcal Infections, Streptococcus
- Published
- 1948
- Full Text
- View/download PDF
43. Erythrocyte sedimentation rate determinations in poliomyelitis and other infections of the central nervous system and meninges.
- Author
-
HARTMAN TL and WEINSTEIN L
- Subjects
- Humans, Blood Sedimentation, Central Nervous System, Clinical Laboratory Techniques, Hematologic Tests, Meninges, Poliomyelitis diagnosis
- Published
- 1948
- Full Text
- View/download PDF
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