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Tustin AW, Cannon DL. Analysis of biomonitoring data to assess employer compliance with OSHA's permissible exposure limits for air contaminants. Am J Ind Med 2022; 65:81-91. [PMID: 34865238 DOI: 10.1002/ajim.23317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 11/12/2022]
Abstract
BACKGROUND The Occupational Safety and Health Administration (OSHA) regulates exposures to hazardous chemicals in workplace air. When contemporaneous exposure measurements are unavailable, retrospective analysis of biomarkers could provide valuable information about workers' exposures. METHODS Single-compartment pharmacokinetic (PK) models were created to relate the concentration of a chemical in the air to the concentration of the chemical or its metabolite in workers' blood or urine. OSHA utilized the PK models in investigations of three fatal incidents in which workers were exposed to nickel carbonyl, methyl bromide, or styrene. To obtain the minimum plausible estimate of each exposure, OSHA used conservative assumptions about parameters such as workers' inhalation rates, baseline levels of biomarker, and chemicals' volumes of distribution. RESULTS OSHA analyzed a worker's urinary nickel concentration and concluded that his 8-h time-weighted average exposure to nickel carbonyl was at least 0.06 mg/m3 . Analysis of a worker's postexposure, premortem blood bromide level revealed that his exposure to methyl bromide was at least 181 mg/m3 . Post-mortem blood styrene measurements suggested that a third worker's exposure to styrene was at least 625 mg/m3 . These exposures exceeded OSHA's permissible exposure limits of 0.007 mg/m3 for nickel carbonyl, 80 mg/m3 for methyl bromide, and 426 mg/m3 for styrene. OSHA successfully cited the three employers for violations of chemical exposure limits. CONCLUSIONS Analysis of biomarkers via PK modeling enables retrospective evaluations of workers' acute exposures to hazardous chemicals. These techniques are useful to occupational regulators who assess employer compliance with mandatory exposure limits.
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Affiliation(s)
- Aaron W. Tustin
- Office of Occupational Medicine and Nursing, Directorate of Technical Support and Emergency Management Occupational Safety and Health Administration Washington District of Columbia USA
| | - Dawn L. Cannon
- Office of Occupational Medicine and Nursing, Directorate of Technical Support and Emergency Management Occupational Safety and Health Administration Washington District of Columbia USA
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Tustin AW, Kundu-Orwa S, Lodwick J, Cannon DL, McCarthy RB. An outbreak of work-related asthma and silicosis at a US countertop manufacturing and fabrication facility. Am J Ind Med 2022; 65:12-19. [PMID: 34671999 DOI: 10.1002/ajim.23304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/15/2021] [Accepted: 10/08/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND Outbreaks of severe silicosis have affected workers who fabricate artificial stone countertops. Work-related asthma (WRA) has not been a prominent feature of those prior outbreaks. METHODS This report describes an outbreak of WRA and silicosis at a facility that manufactures and fabricates chemical-resistant countertops comprised of sand, epoxy resin, and phthalic anhydride (PA), a known respiratory sensitizer. The multi-disciplinary investigation included clinical examinations of workers, an industrial hygiene survey with qualitative and quantitative exposure assessments, and a cross-sectional questionnaire. RESULTS Engineering controls and personal protective equipment were inadequate. Some workers were exposed to PA or silica above permissible exposure limits established by the Occupational Safety and Health Administration (OSHA). Clinical and epidemiologic investigations identified 16 workers with confirmed or suspected WRA. Two years later, after OSHA began to enforce its new silica standards, 12 workers received medical surveillance for silicosis. Of these 12 workers, four (33.3%) were diagnosed with silicosis based on abnormal chest computed tomography examinations. CONCLUSIONS Artificial stone countertop workers can develop asthma or silicosis. Risk of asthma may be highest in workers exposed to asthmagens such as PA and epoxy resins while manufacturing the artificial stone material.
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Affiliation(s)
- Aaron W Tustin
- Office of Occupational Medicine and Nursing, Directorate of Technical Support and Emergency Management, Occupational Safety and Health Administration, U.S. Department of Labor, Washington, District of Columbia, USA
| | - Sylvia Kundu-Orwa
- Austin Area Office, Occupational Safety and Health Administration, U.S. Department of Labor, Austin, Texas, USA
| | - Jeffrey Lodwick
- Salt Lake Technical Center, Directorate of Technical Support and Emergency Management, Occupational Safety and Health Administration, U.S. Department of Labor, Salt Lake City, Utah, USA
| | - Dawn L Cannon
- Office of Occupational Medicine and Nursing, Directorate of Technical Support and Emergency Management, Occupational Safety and Health Administration, U.S. Department of Labor, Washington, District of Columbia, USA
| | - Ronda B McCarthy
- National Medical Surveillance Services, Concentra, Waco, Texas, USA
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Hoang A, Fagan K, Cannon DL, Rayasam SDG, Harrison R, Shusterman D, Singla V. Assessment of Methylene Chloride-Related Fatalities in the United States, 1980-2018. JAMA Intern Med 2021; 181:797-805. [PMID: 33871539 PMCID: PMC8056315 DOI: 10.1001/jamainternmed.2021.1063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 02/23/2021] [Indexed: 12/05/2022]
Abstract
Importance Methylene chloride is a halogenated organic solvent widely used in paint strippers, cleaners, adhesives, and sealants. Despite label warnings and occupational standards, methylene chloride-related fatalities continue to occur in the United States. Objective To identify and analyze methylene chloride-related fatalities in the US. Design, Setting, and Participants For this case series, we conducted systematic searches of sources, including PubMed and government databases, for unintentional fatalities in the US that were associated with exposure to methylene chloride or products containing methylene chloride between 1980 and 2018. We reviewed all available information, including inspection reports, autopsy reports, and medical records; data analyses were conducted from August 2018 to August 2020. Cases were categorized as those occurring in the home (consumer deaths) or at work (occupational deaths). Exposures Methylene chloride or products containing methylene chloride. Main Outcomes and Measures To determine characteristics of the methylene chloride-related fatalities, we recorded demographic information; the setting; circumstances, including information on safety measures used, if available; and products used. Where medical records were available, we recorded toxicology results and autopsy findings. We also obtained data about nonfatal methylene chloride cases from the American Association of Poison Control Centers. Results From 1980 to 2018, 85 methylene chloride-related fatalities were identified in the US, including 74 (87%) in occupational settings; of those who died, 75 (94%) were men, and for the 70 cases with available information, the median (interquartile range) age of the decedents was 31 (24-46) years. Paint strippers were the most common products involved in methylene chloride-related fatalities (n = 60). The proportion of occupational fatalities related to paint stripping increased from 22 (55%) before 2000 to 30 (88%) after 2000. Similarly, occupational fatalities associated with bathtub or paint stripping in bathrooms increased from 2 (5%) before 2000 to 21 (62%) after 2000. From 1985 to 2017, the American Association of Poison Control Centers documented 37 201 nonfatal methylene chloride cases, with a decrease in the annual number of cases starting in the late 1990s. Conclusions and Relevance Results of this case series demonstrated that despite regulations to address the toxic effects of methylene chloride use for consumers and workers, there are continuing fatalities in the US, particularly in occupational settings. Prevention of fatalities associated with methylene chloride exposure should emphasize the use of safer substitutes, rather than hazard warnings or reliance on personal protective equipment.
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Affiliation(s)
- Anh Hoang
- School of Medicine, University of California, San Francisco
| | - Kathleen Fagan
- Office of Occupational Medicine and Nursing, Occupational Safety and Health Administration, Washington, DC
- Now Retired
| | - Dawn L. Cannon
- Office of Occupational Medicine and Nursing, Occupational Safety and Health Administration, Washington, DC
| | - Swati D. G. Rayasam
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco
| | - Robert Harrison
- Division of Occupational and Environmental Medicine, Department of Medicine, University of California, San Francisco
| | - Dennis Shusterman
- Division of Occupational and Environmental Medicine, Department of Medicine, University of California, San Francisco
| | - Veena Singla
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco
- Now with Healthy People and Thriving Communities, Natural Resources Defense Council, San Francisco, California
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Karasick AS, Thomas RJ, Cannon DL, Fagan KM, Bray PA, Hodgson MJ, Tustin AW. Notes from the Field: Amphetamine Use Among Workers with Severe Hyperthermia - Eight States, 2010-2019. MMWR Morb Mortal Wkly Rep 2020; 69:1004-1005. [PMID: 32730241 PMCID: PMC7392391 DOI: 10.15585/mmwr.mm6930a5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Tustin AW, Lamson GE, Jacklitsch BL, Thomas RJ, Arbury SB, Cannon DL, Gonzales RG, Hodgson MJ. Evaluation of Occupational Exposure Limits for Heat Stress in Outdoor Workers - United States, 2011-2016. MMWR Morb Mortal Wkly Rep 2018; 67:733-737. [PMID: 29975679 PMCID: PMC6048976 DOI: 10.15585/mmwr.mm6726a1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Heat stress, an environmental and occupational hazard, is associated with a spectrum of heat-related illnesses, including heat stroke, which can lead to death. CDC's National Institute for Occupational Safety and Health (NIOSH) publishes recommended occupational exposure limits for heat stress (1). These limits, which are consistent with those of the American Conference of Governmental Industrial Hygienists (ACGIH) (2), specify the maximum combination of environmental heat (measured as wet bulb globe temperature [WBGT]) and metabolic heat (i.e., workload) to which workers should be exposed. Exposure limits are lower for workers who are unacclimatized to heat, who wear work clothing that inhibits heat dissipation, and who have predisposing personal risk factors (1,2). These limits have been validated in experimental settings but not at outdoor worksites. To determine whether the NIOSH and ACGIH exposure limits are protective of workers, CDC retrospectively reviewed 25 outdoor occupational heat-related illnesses (14 fatal and 11 nonfatal) investigated by the Occupational Safety and Health Administration (OSHA) from 2011 to 2016. For each incident, OSHA assessed personal risk factors and estimated WBGT, workload, and acclimatization status. Heat stress exceeded exposure limits in all 14 fatalities and in eight of 11 nonfatal illnesses. An analysis of Heat Index data for the same 25 cases suggests that when WBGT is unavailable, a Heat Index screening threshold of 85°F (29.4°C) could identify potentially hazardous levels of workplace environmental heat. Protective measures should be implemented whenever the exposure limits are exceeded. The comprehensive heat-related illness prevention program should include an acclimatization schedule for newly hired workers and unacclimatized long-term workers (e.g., during early-season heat waves), training for workers and supervisors about symptom recognition and first aid (e.g., aggressive cooling of presumed heat stroke victims before medical professionals arrive), engineering and administrative controls to reduce heat stress, medical surveillance, and provision of fluids and shady areas for rest breaks.
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Affiliation(s)
- Stephanie Sayre Smith
- Fort Belvoir Community Hospital, Fort Belvoir, VA, Occupational Safety and Health, Administration, Washington, DC National Institute of Environmental, Health Sciences, Bethesda, MD
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Abstract
BACKGROUND Hospital readmissions are common and costly. Our goal was to determine the association between depressive symptoms and readmission within 30 days following hospital discharge in older adults. METHODS We analyzed data from a study of 789 persons aged 65 years or older admitted to a 20-bed acute care for elders (ACE) hospital unit from May 2009 to July 2011. Depressive symptoms were recorded within 24-hours of admission to the hospital unit, using the Center for Epidemiologic Studies -Depression (CES-D) Scale. The primary outcome was readmission to hospital within 30 days of discharge. RESULTS The mean age was 77 years; 66% were female, 72% were White, and 59% were unmarried. On average, older patients reported 2.6 comorbid conditions. Sixteen percent were classified with high depressive symptoms (CES-D ≥ 16). The readmission rate within 30 days was 15%. Older patients with high depressive symptoms had more than 1.6 times the odds (OR 1.66; 95% CI: 1.01-2.74) of being readmitted within 30-days, as compared to those with low depressive symptoms (CES-D < 16), after adjustment for age, race/ethnicity, sex, marital status and comorbid conditions. CONCLUSION High depressive symptoms increased the risk of hospital readmission within 30 days of discharge after adjusting for relevant covariates. In-hospital screening for depressive symptoms may identify older persons at risk for recurrent hospital admissions.
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Affiliation(s)
- Ivonne M Berges
- Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, USA
| | - Sania Amr
- Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, USA
| | - Danielle S Abraham
- Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, USA
| | - Dawn L Cannon
- Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, USA
| | - Glenn V Ostir
- Department of Epidemiology and Public Health, Division of Gerontology, University of Maryland School of Medicine, USA
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Raut CG, Yadav PD, Towner JS, Amman BR, Erickson BR, Cannon DL, Sivaram A, Basu A, Nichol ST, Mishra AC, Mourya DT. Isolation of a novel adenovirus from Rousettus leschenaultii bats from India. Intervirology 2012; 55:488-90. [PMID: 22572722 DOI: 10.1159/000337026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 02/02/2012] [Indexed: 11/19/2022] Open
Abstract
Surveillance work was initiated to study the presence of highly infectious diseases like Ebola-Reston, Marburg, Nipah and other possible viruses that are known to be found in the bat species and responsible for causing diseases in humans. A novel adenovirus was isolated from a common species of fruit bat (Rousettus leschenaultii) captured in Maharashtra State, India. Partial sequence analysis of the DNA polymerase gene shows this isolate to be a newly recognized member of the genus Mastadenovirus (family Adenoviridae), approximately 20% divergent at the nucleotide level from Japanese BatAdV, its closest known relative.
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Affiliation(s)
- C G Raut
- Microbial Containment Complex, National Institute of Virology, Pune, India
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Schinazi RF, Lloyd RM, Nguyen MH, Cannon DL, McMillan A, Ilksoy N, Chu CK, Liotta DC, Bazmi HZ, Mellors JW. Characterization of human immunodeficiency viruses resistant to oxathiolane-cytosine nucleosides. Antimicrob Agents Chemother 1993; 37:875-81. [PMID: 7684216 PMCID: PMC187791 DOI: 10.1128/aac.37.4.875] [Citation(s) in RCA: 316] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The (-) enantiomers of 2',3'-dideoxy-5-fluoro-3'-thiacytidine [(-)-FTC] and 2',3'-dideoxy-3'-thiacytidine [(-)-BCH-189] were recently shown to inhibit selectively human immunodeficiency viruses (HIV) and hepatitis B virus in vitro. In the current study, the potential for HIV type 1 (HIV-1) resistance to these compounds was evaluated by serial passage of the virus in human peripheral blood mononuclear cells and MT-2 cells in the presence of increasing drug concentrations. Highly drug-resistant HIV-1 variants dominated the replicating virus population after two or more cycles of infection. The resistant variants were cross-resistant to (-)-FTC, (-)-BCH-189, and their (+) congeners but remained susceptible to 2',3'-dideoxycytidine, 3'-azido-3'-deoxythymidine, 3'-fluoro-3'-deoxythymidine, 2',3'-dideoxyinosine, phosphonoformate, the TIBO compound R82150, and the bis(heteroaryl)piperazine derivative U-87201E. Reverse transcriptase derived from drug-resistant viral particles was 15- to 50-fold less susceptible to the 5'-triphosphates of FTC and BCH-189 compared with enzyme from parental drug-susceptible virus. DNA sequence analysis of the reverse transcriptase gene amplified from resistant viruses consistently identified mutations at codon 184 from Met (ATG) to Val (GTG or GTA) or Ile (ATA). Sequence analysis of amplified reverse transcriptase from a patient who had received (-)-BCH-189 therapy for 4 months demonstrated a mixture of the Met-184-to-Val (GTG) mutation and the parental genotype, indicating that the Met-184 mutation can occur in vivo.
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Affiliation(s)
- R F Schinazi
- Veterans Affairs Medical Center, Decatur, Georgia 30033
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Kim HO, Schinazi RF, Shanmuganathan K, Jeong LS, Beach JW, Nampalli S, Cannon DL, Chu CK. L-beta-(2S,4S)- and L-alpha-(2S,4R)-dioxolanyl nucleosides as potential anti-HIV agents: asymmetric synthesis and structure-activity relationships. J Med Chem 1993; 36:519-28. [PMID: 8496934 DOI: 10.1021/jm00057a001] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In order to study the structure-activity relationships of L-(2S,4S)- and L-(2S,4R)-dioxolanyl nucleoside as potential anti-HIV agents, various enantiomerically pure L-(2S,4S)- and (2S,4R)-dioxolanylpyrimidine and -purine nucleosides have been synthesized and evaluated against HIV-1 in human peripheral blood mononuclear (PBM) cells. The enantiomerically pure key intermediate 8 has been synthesized in six steps from 1,6-anhydro-beta-L-gulose (2), and compound 8 was condensed with 5-substituted pyrimidines, 6-chloropurine, and 2,6-disubstituted purine to obtain various dioxolanylpyrimidine and -purine nucleosides, respectively. Among the compound synthesized, 5-fluorocytosine derivative 29 was found to exhibit the most potent anti-HIV activity (EC50 = 0.0012 microM) although it was toxic (IC50 = 10.0 microM). The order of anti-HIV potency of pyrimidine analogues was as follows: 5-fluorocytosine (beta-isomer) > cytosine (beta-isomer) > 5-fluorocytosine (alpha-isomer) > 5-iodocytosine (beta-isomer) > cytosine (alpha-isomer) > 5-bromocytosine (beta-isomer) > thymine (beta-isomer) > 5-methylcytosine (alpha-isomer) > 5-iodocytosine (alpha-isomer) > 5-chlorocytosine (beta-isomer). The anti-HIV potency of purine analogues was found to be in the following decreasing order: 2,6-diaminopurine (beta-isomer) > 2-chloroadenine (alpha-isomer) > 2-fluoroadenine (beta-isomer) > adenine (beta-isomer) > 2-amino-6-chloropurine (alpha-isomer) > 2-amino-6-chloropurine (beta-isomer) > guanine (beta-isomer) > 2-fluoroadenine (alpha-isomer) > adenine (alpha-isomer) > 2,6-diaminopurine (alpha-isomer) > N6-methyladenine (beta-isomer). It is interesting to note that the alpha-5-fluorocytosine analogue exhibited an excellent anti-HIV activity (EC50 = 0.063 microM) without cytotoxicity up to 100 microM in PBM cell.
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Affiliation(s)
- H O Kim
- Department of Medicinal Chemistry, College of Pharmacy, University of Georgia, Athens 30602
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Kim HO, Schinazi RF, Nampalli S, Shanmuganathan K, Cannon DL, Alves AJ, Jeong LS, Beach JW, Chu CK. 1,3-dioxolanylpurine nucleosides (2R,4R) and (2R,4S) with selective anti-HIV-1 activity in human lymphocytes. J Med Chem 1993; 36:30-7. [PMID: 8421287 DOI: 10.1021/jm00053a004] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In order to study the structure-activity relationships of dioxolane nucleosides as potential anti-HIV-1 agents, various enantiomers of pure dioxolanylpurine nucleosides were synthesized and evaluated against HIV-1 in human peripheral blood mononuclear cells. The enantiomerically pure key intermediate 1, which was synthesized in nine steps from 1,6-anhydro-beta-D-mannose, was condensed with 6-chloropurine, 6-chloro-2-fluoropurine, and 2,6-dichloropurine in the presence of TMS triflate. The chloro or fluoro substituents were readily converted into amino, N-methylamino, hydroxy, methoxy, thiol, and methylthio under appropriate reaction conditions. Upon evaluation of these dioxolanes, the guanine derivative 24 exhibited the most potent anti-HIV-1 activity without cytotoxicity up to 100 microM in various cells. The decreasing antiviral activity order of beta-isomers was as follows: guanine > 6-chloro-2-aminopurine > 2-fluoroadenine > or = adenine > or = 2,6-diaminopurine > hypoxanthine > 2-chloroadenine > 6-chloropurine approximately equal to N6-methyladenine approximately equal to 6-mercaptopurine approximately equal to 6-(methylthio)purine.
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Affiliation(s)
- H O Kim
- Department of Medicinal Chemistry, College of Pharmacy, University of Georgia, Athens 30602
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Schinazi RF, Sommadossi JP, Saalmann V, Cannon DL, Xie MY, Hart GC, Smith GA, Hahn EF. Activities of 3'-azido-3'-deoxythymidine nucleotide dimers in primary lymphocytes infected with human immunodeficiency virus type 1. Antimicrob Agents Chemother 1990; 34:1061-7. [PMID: 2393266 PMCID: PMC171759 DOI: 10.1128/aac.34.6.1061] [Citation(s) in RCA: 161] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The relative antiviral potencies of five nucleotide heterodimers of 3'-azido-3'-deoxythymidine (AZT), 3'-azido-3'-deoxythymidilyl-(5',5')-2'-3'-dideoxy-5'-adenylic acid (AZT-P-ddA), 3'-azido-3'-deoxythymidilyl-(5',5')-2',3'-dideoxy-5'-inosinic acid (AZT-P-ddI), and the corresponding 2-cyanoethyl congeners AZT-P(CyE)-ddA and AZT-P(CyE)-ddI, were determined in primary human peripheral blood mononuclear cells infected with human immunodeficiency virus type 1. The homodimer 3'-azido-3'-deoxythymidilyl-(5',5')-3'-azido-3'-deoxythymidilic acid (AZT-P-AZT) was also included for comparison. The potencies of the compounds were AZT-P-ddA greater than or equal to AZT-P-ddI greater than AZT-P(CyE)-ddA greater than or equal to AZT-P(CyE)-ddI greater than or equal to AZT greater than AZT-P-AZT. Whereas AZT-P-ddA and AZT-P-ddI had in vitro therapeutic indices greater than that of AZT, the homodimer of AZT had a low therapeutic index. AZT-P-ddI exhibited the lowest toxicity in peripheral blood mononuclear, Vero, or CEM cells. Combination studies between AZT and 2',3'-dideoxyinosine (ddI) at nontoxic concentrations indicated a synergistic interaction at a drug ratio of 1:100. At higher ratios (1:500 and 1:1,000), the interactions were synergistic only at concentrations that produced up to 75% virus inhibition. At higher levels of antiviral effects, this combination was antagonistic, as determined by the multiple drug effect analysis method. AZT-P-ddI was about 10-fold less toxic than AZT to human granulocyte-macrophage progenitor cells. However, no significant difference was apparent when the compounds were evaluated against cells of the erythroid lineage. The greater antiviral activity and lower toxicity of this compound could not be attributed to the extracellular decomposition of the dimer in media at physiological temperature and pH. However, in acidic solutions, AZT-P-ddI decomposed in a pH-dependent manner. Advanced preclinical studies with this heterodimer of two clinically effective antiretroviral agents should be considered.
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Affiliation(s)
- R F Schinazi
- Veterans Affairs Medical Center, Decatur, Georgia 30033
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Schinazi RF, Chu CK, Babu JR, Oswald BJ, Saalmann V, Cannon DL, Eriksson BF, Nasr M. Anthraquinones as a new class of antiviral agents against human immunodeficiency virus. Antiviral Res 1990; 13:265-72. [PMID: 1697740 DOI: 10.1016/0166-3542(90)90071-e] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Various anthraquinones substituted with hydroxyl, amino, halogen, carboxylic acid, substituted aromatic group, and sulfonate were tested to determine their activity against human immunodeficiency virus type 1 (HIV-1) in primary human lymphocytes. Among the compounds tested, polyphenolic and/or polysulfonate substituted anthraquinones were found to possess the most potent antiviral activity. Hypericin, an anthraquinone dimer previously shown to have activity against nonhuman retroviruses also exhibited anti-HIV-1 activity in lymphocytes. the active anthraquinones inhibited HIV-1 reverse transcriptase. However, this enzyme inhibition was selective only for 1,2,5,8-tetrahydroanthraquinone and hypericin. Hypericin interacts nonspecifically with protein suggesting that this effect may dictate its inhibitory activity against the viral reverse transcriptase.
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Affiliation(s)
- R F Schinazi
- Veterans Affairs Medical Center, Decatur, GA 30033
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Schinazi RF, Cannon DL, Arnold BH, Martino-Saltzman D. Combinations of isoprinosine and 3'-azido-3'-deoxythymidine in lymphocytes infected with human immunodeficiency virus type 1. Antimicrob Agents Chemother 1988; 32:1784-7. [PMID: 2469387 PMCID: PMC176018 DOI: 10.1128/aac.32.12.1784] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Since clinical trials are being planned with the immunomodulating drug isoprinosine combined with the antiviral drug 3'-azido-3'-deoxythymidine (AZT) in patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex, it is important to determine the type of antiviral interaction produced by these drugs in vitro. Such a combined modality may not only produce enhanced antiviral effects but also may have a valuable immunorestorative action. The interaction of several ratios of AZT and isoprinosine on the replication of human immunodeficiency virus type 1 in human peripheral blood mononuclear cells was determined by reverse transcriptase assay of disrupted virus obtained from supernatants of cells that were exposed to virus and the drugs separately and in combination and by a human immunodeficiency virus type 1 p24 enzyme immunoassay of the same supernatants. The correlation between the reverse transcriptase and enzyme immunoassay data was high. The antiviral activity of AZT alone was neither diminished nor augmented when AZT was used in combination with isoprinosine. Isoprinosine did not enhance virus yield when used alone or in combination with AZT in peripheral blood mononuclear cells, nor did it affect the growth of uninfected cells. The in vitro results indicate that this combination did not decrease the efficacy of AZT or exacerbate virus replication.
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Affiliation(s)
- R F Schinazi
- Veterans Administration Medical Center, Decatur, Georgia 30033
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16
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Chu CK, Schinazi RF, Arnold BH, Cannon DL, Doboszewski B, Bhadti VB, Gu ZP. Comparative activity of 2',3'-saturated and unsaturated pyrimidine and purine nucleosides against human immunodeficiency virus type 1 in peripheral blood mononuclear cells. Biochem Pharmacol 1988; 37:3543-8. [PMID: 3178868 DOI: 10.1016/0006-2952(88)90383-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- C K Chu
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Georgia, Athens 30602
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Cannon DL. History of the Medical Association of the state of Alabama. J Med Assoc State Ala 1977; 46:20-5. [PMID: 323389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Cannon DL. History of the Medical Association of the State of Alabama. J Med Assoc State Ala 1977; 47:20-4 cont. [PMID: 319190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Cannon DL. History of the Medical Association of the State of Alabama. J Med Assoc State Ala 1977; 46:20-4 contd. [PMID: 335009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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