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Soule EK, Mayne S, Snipes W, Guy MC, Breland A, Fagan P. Reactions to a Hypothetical Ban of Open-System Electronic Cigarettes Among People Who Currently Use Electronic Cigarettes. Nicotine Tob Res 2024:ntae020. [PMID: 38408200 DOI: 10.1093/ntr/ntae020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/13/2023] [Accepted: 01/19/2024] [Indexed: 02/28/2024]
Abstract
INTRODUCTION Policies limiting electronic cigarette (ECIG) device and liquid characteristics have been considered to prevent dependence potential and youth product appeal. "Open-system" ECIGs allow people to adjust device and liquid characteristics, which may undermine these policies. This study examined anticipated reactions to a policy prohibiting the sale of open-system ECIG devices in the United States using concept mapping. METHODS In 2020, adults who reported ECIG use in the past 30 days (n = 70; 45.1% women; mean age = 33.0, SD = 10.6) recruited from a research registry of individuals from across the United States provided statements into a shared list that completed a prompt: "If open-system vaping devices were no longer sold in the US and only closed-system vaping devices were available, what is a specific reaction or response you would have?" at a study website. Participants rated statements (1-7) on how true the statements were for them. Multidimensional scaling and hierarchical cluster analyses were used to identify thematic clusters. Mean ratings of statements were calculated and compared based on the type of ECIG used and current cigarette smoking status. RESULTS Participants generated 85 unique statements. The analysis identified eight themes that were organized into two broad groups. The first group of five clusters described behavioral responses to the hypothetical policy (Loopholes, Switch to Closed-System ECIGs, Legal Approaches to Use Open-System ECIGs, ECIG Use Cessation, Switch to non-ECIG Products). The second group of three clusters described psychological responses to the hypothetical policy (Closed-System ECIG Cons, Psychological Responses, Policy Outcome Concerns). CONCLUSIONS While a ban on open-system ECIG devices may have positive impacts on public health, policy loopholes, and consumer behaviors may undermine the policy. Efforts to support policy enforcement could increase policy effectiveness. IMPLICATIONS Open-system electronic cigarettes (ECIGs) that allow people who use ECIGs to modify ECIG device and liquid characteristics may limit the effectiveness of policies that establish product standards which attempt to limit nicotine delivery and flavor content in ECIG liquids. This study identified predicted reactions to a hypothetical policy prohibiting the sale of open-system ECIGs in the United States. Results suggest that people who use ECIGs may view a policy prohibiting open-system ECIGs unfavorably, but would be willing to use closed-system ECIGs. However, many ECIG users may attempt to find loopholes in the policy or alternative sources to purchase open-system ECIGs if open-systems were banned. Future research should identify strategies for tobacco regulatory policy enforcement to increase effectiveness.
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Affiliation(s)
- Eric K Soule
- Department of Health Education and Promotion, East Carolina University, Greenville, NC, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
| | - Shannon Mayne
- Department of Health Education and Promotion, East Carolina University, Greenville, NC, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
| | - William Snipes
- Department of Health Education and Promotion, East Carolina University, Greenville, NC, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
| | - Mignonne C Guy
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
- Department of African American Studies, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Alison Breland
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
- Department of Psychology, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Pebbles Fagan
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
- Department of Health Behavior and Health Education, Fay W. Boozman College of Public Health, Center for the Study of Tobacco, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Soule EK, Mayne S, Snipes W, Heym M, Coffey AD, Guy MC, Breland A, Fagan P. Electronic Cigarette Users' Reactions and Responses to a Hypothetical Nicotine Concentration Reduction in Electronic Cigarette Liquids. Subst Use Misuse 2023:1-10. [PMID: 37222484 DOI: 10.1080/10826084.2023.2212280] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Background: Regulations limiting nicotine in electronic cigarettes (e-cigarettes) have been proposed or implemented. Little is known about e-cigarette users' reactions to reducing e-cigarette liquid nicotine concentration. Methods: We used concept mapping to describe e-cigarette users' reactions to a 50% reduction in the nicotine concentration of their e-cigarette liquids. In 2019, current e-cigarette users who used e-cigarette liquid with greater than 0 mg/ml nicotine concentration completed an online study. Participants (n = 71, mean age = 34.9 (SD = 11.0), 50.7% women), brainstormed statements completing a prompt: "If the e-liquid that I use now in my e-cigarette/vaping device was only available in half the nicotine concentration or amount that I use now, a specific action I would take or a specific reaction I would have is…", Participants then sorted a final list of 67 statements into piles of similar content and rated statements on how true the statements would be for them. Multidimensional scaling and hierarchical cluster analyses identified thematic clusters. Results: Eight clusters were identified: (1) Replacement Product Seeking, (2) Mental Preparations and Expectations, (3) Use the New Liquid, (4) Information Seeking, (5) Compensation Behaviors, (6) Opportunity for E-Cigarette Reduction, (7) Physical and Psychological Effects, and (8) Replacement with non-E-Cigarette Products and Behaviors. Cluster ratings suggested many participants would search for other e-cigarette products/liquids to replace their current liquids, but using other tobacco products (e.g., cigarettes) may be less likely. Conclusions: If nicotine concentrations were decreased in e-cigarette liquids, e-cigarette users may attempt to purchase different e-cigarette products or modify their products to achieve desired effects.
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Affiliation(s)
- Eric K Soule
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shannon Mayne
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - William Snipes
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Molly Heym
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - AnneMarie D Coffey
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mignonne C Guy
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of African American Studies, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Alison Breland
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Psychology, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Pebbles Fagan
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Health Behavior and Health Education, Fay W. Boozman College of Public Health, Center for the Study of Tobacco, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Soule EK, Mayne S, Snipes W, Do EK, Theall T, Höchsmann C, Talih S, Martin CK, Eissenberg T, Fuemmeler BF. Electronic Cigarette Nicotine Flux, Nicotine Yield, and Particulate Matter Emissions: Impact of Device and Liquid Heterogeneity. Nicotine Tob Res 2023; 25:412-420. [PMID: 35965260 PMCID: PMC9910146 DOI: 10.1093/ntr/ntac196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 10/26/2021] [Revised: 07/29/2022] [Accepted: 08/10/2022] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Electronic cigarettes (ECIGs) heat a nicotine-containing liquid to produce an inhalable aerosol. ECIG power (wattage) and liquid nicotine concentration are two factors that predict nicotine emission rate ("flux"). These factors can vary greatly across devices and users. AIMS AND METHODS The purpose of this study was to examine ECIG device and liquid heterogeneity in "real world" settings and the association with predicted nicotine flux, nicotine yield, and total particulate matter (TPM) emissions. Past 30-day ECIG users (n = 84; mean age = 23.8 years [SD = 9.6]) reported device and liquid characteristics. Device power was measured via multimeter, device display screens, or obtained via labeling. Liquid nicotine concentration was obtained via labeling or through chemical analysis. Predicted nicotine flux, nicotine yield, and TPM associated with 10 4-second puffs were calculated for participants' primary devices. RESULTS Participants' primary devices were box mods (42.9%), disposable vapes (20.2%), and pod mods (36.9%). Most participants (65.5%) reported not knowing their primary device wattage. Rebuildable/box mods had the greatest power range (11.1-120.0 W); pod mod power also varied considerably (4.1-21.7 W). Unlike device wattage, most participants (95.2%) reported knowing their liquid nicotine concentration, which ranged from 3.0 to 86.9 mg/ml (M = 36.0, SD = 29.3). Predicted nicotine flux varied greatly across products (range =12.0-160.1 μg/s, M = 85.6 μg/s, SD = 34.3). Box mods had the greatest variability in wattage and predicted nicotine flux, nicotine yield, and TPM yield. CONCLUSIONS ECIG device and liquid heterogeneity influence nicotine and other toxicant emissions. Better measurement of ECIG device and liquid characteristics is needed to understand nicotine and toxicant emissions and to inform regulatory policy. IMPLICATIONS ECIG device and liquid heterogeneity cause great variability in nicotine flux and toxicants emitted. These data demonstrate the need to examine device and liquid characteristics to develop empirically informed, health-promoting regulatory policies. Policies may include setting product standards such that ECIG products cannot (1) have nicotine fluxes much greater than that of a cigarette to decrease the risk of dependence, (2) have nicotine fluxes that are very low and thus would have minimal appeal to cigarette smokers and may serve as starter products for youth or nontobacco users, and (3) emit large amounts of particulate matter and other toxicants.
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Affiliation(s)
- Eric K Soule
- Department of Health Education and Promotion, East Carolina University, Greenville, NC, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
| | - Shannon Mayne
- Department of Health Education and Promotion, East Carolina University, Greenville, NC, USA
| | - William Snipes
- Department of Health Education and Promotion, East Carolina University, Greenville, NC, USA
| | - Elizabeth K Do
- Health Behavior and Policy, Virginia Commonwealth University, Richmond, VA, USA
- Schroeder Institute, Truth Initiative, Washington, DC, USA
| | - Travis Theall
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Christoph Höchsmann
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Soha Talih
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
- Mechanical Engineering Department, Maroun Semaan Faculty of Engineering and Architecture, American University of Beirut, Beirut, Lebanon
| | - Corby K Martin
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Thomas Eissenberg
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
| | - Bernard F Fuemmeler
- Health Behavior and Policy, Virginia Commonwealth University, Richmond, VA, USA
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
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Soule EK, Mayne S, Snipes W, Thomas L, Guy MC, Breland A, Fagan P. Electronic cigarette users' reactions and responses to a hypothetical ban of flavoured electronic cigarette liquids. Tob Control 2022; 31:s197-s205. [PMID: 36328459 PMCID: PMC9661374 DOI: 10.1136/tc-2022-057454] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/27/2022] [Indexed: 11/22/2022]
Abstract
Regulations have been proposed to limit e-cigarette flavours, but limited research has examined potential impacts of such policies. This study examined adult e-cigarette users’ reactions to a hypothetical e-cigarette flavour ban.
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Affiliation(s)
- Eric K Soule
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA,Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shannon Mayne
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA,Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - William Snipes
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA,Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Luke Thomas
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA,Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mignonne C Guy
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA,Department of African American Studies, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Alison Breland
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA,Department of Psychology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Pebbles Fagan
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA,Department of Health Behavior and Health Education, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Kava CM, Soule EK, Seegmiller L, Gold E, Snipes W, Westfield T, Wick N, Afifi R. "Taking Up a New Problem": Context and Determinants of Pod-Mod Electronic Cigarette Use Among College Students. Qual Health Res 2021; 31:703-712. [PMID: 33213262 PMCID: PMC7878307 DOI: 10.1177/1049732320971236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this article, we explore the context and determinants of pod-mod electronic cigarette (ECIG) use among college students aged 18 to 24 in the United States. We conducted semi-structured interviews with 55 students (M age = 20 years, 56% female, 65% White) on three campuses in the Northwest, Midwest, and Southeast. We performed a thematic analysis. Students described ECIG use by peers, increased ECIG exposure and prevalence in college, and school-related stress as reasons for vaping. Pod-mod features such as convenience, design, easy concealment, and flavors made vaping more appealing. Negative aspects of vaping included addiction, cost, and possible health consequences. Most viewed vaping as a college behavior and intended to quit after graduation. Our results show that the college environment plays a major role in young adult ECIG use. These findings can inform the development of targeted interventions to prevent and control uptake of ECIGs by young adults.
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Affiliation(s)
| | - Eric K Soule
- East Carolina University, Greenville, North Carolina, USA
| | - Laura Seegmiller
- University of Iowa College of Public Health, Iowa City, Iowa, USA
| | - Emily Gold
- East Carolina University, Greenville, North Carolina, USA
| | - William Snipes
- East Carolina University, Greenville, North Carolina, USA
| | - Taya Westfield
- University of Iowa College of Public Health, Iowa City, Iowa, USA
| | - Noah Wick
- University of Iowa College of Public Health, Iowa City, Iowa, USA
| | - Rima Afifi
- University of Iowa College of Public Health, Iowa City, Iowa, USA
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Kim S, Korhonen M, Wilborn W, Foldesy R, Snipes W, Hodgen GD, Anderson FD. Antiproliferative effects of low-dose micronized progesterone. Fertil Steril 1996; 65:323-31. [PMID: 8566256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To study the pharmacodynamic effects of oral micronized P on endometrial maturation. DESIGN This was a controlled, open, parallel group, pilot study. SETTING The experiment was performed in an outpatient academic clinical research unit. PATIENTS Twelve healthy, P-challenged, estrogen-primed, postmenopausal women participated in the study. INTERVENTIONS Patients were given 300 mg micronized P daily (8:00 A.M.) or twice (8:00 A.M. and 4:00 P.M.) daily from study days 1 through 14 after estrogen priming for 30 days. Blood samples were taken at 0, 0.5, 1, 1.5, 2, 3, 4, 6, and 8 hours after the 8:00 A.M. dose on study day 1 and 14 and again at 8:00 and 9:30 A.M. on days 3 and 5 fasting, days 7 and 9 after a fatty meal, and day 11 after a high fiber meal. Endometrial biopsies were taken on day 1 and 14. MAIN OUTCOME MEASURES Progesterone concentrations were measured. Endometrial biopsies were studied for effects on histology, glycogen content of glands, ribosomal RNA, and nuclear estrogen receptors in glands, surface epithelium, and stroma. RESULTS Day 1 and 14 P kinetics were similar for 8 hours. Dose-dependent increases in glandular glycogen, decrease in ribosomal RNA, and decrease in nuclear estrogen receptors were demonstrated. CONCLUSIONS Oral micronized P can induce antiproliferative changes in the human endometrium at doses lower than those required for transformation of the endometrium to a full secretory state.
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Affiliation(s)
- S Kim
- Department of Obstetrics and Gynecology, Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, USA
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Abstract
The bioavailability, pharmacokinetics, and metabolism of a novel transbuccal delivery system of testosterone was investigated in five healthy eugonadal men. Total serum testosterone (T), dihydrotestosterone (DHT), and sex hormone-binding globulin (SHBG) concentrations were determined from blood samples obtained at 8:00 a.m. (zero hour), and 30 min and 1, 2, 3, 4, 6, 12 and 24 hours later on day 1, and again on day 2, after dosing. This single transbuccal administration of Buccal T induced a prompt rise in serum T and DHT concentrations. The maximal concentration (Cmax) of T was 19.56 7.64 ng/mL (mean +/- SD; 5.3-fold increase from the baseline) at< 30 min (Tmax) after administration. The elimination half-life of Buccal T was about 1.75 h. Serum DHT peaked at 1 h at a concentration of 1.46 +/- 0.46 ng/mL (2.3-fold increase from the baseline). The drug was well tolerated. This study suggests that the Buccal T is a promising delivery system for natural T.
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Affiliation(s)
- S Kim
- Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk 23507, USA
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Archer DF, Fahy GE, Viniegra-Sibal A, Anderson FD, Snipes W, Foldesy RG. Initial and steady-state pharmacokinetics of a vaginally administered formulation of progesterone. Am J Obstet Gynecol 1995; 173:471-7; discussion 477-8. [PMID: 7645623 DOI: 10.1016/0002-9378(95)90268-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE The pharmacokinetics of a 100 mg vaginal progesterone suppository was evaluated on days 1 and 7 and a 200 mg suppository on day 14. All the volunteers were given oral 17 beta-estradiol during the study. STUDY DESIGN Ten postmenopausal women volunteered for this study. Progesterone was given as a vaginal suppository. Peripheral venous samples were obtained at appropriate intervals and analyzed for 17 beta-estradiol and progesterone levels. Area under the curve for progesterone was assessed by the trapezoidal method. Statistical analysis was performed by a one-way analysis of variance. RESULTS Serum 17 beta-estradiol levels ranged from 22 to 182 pg/ml. Maximal serum progesterone levels ranged from 5.7 to 20.9 ng/ml, with the mean maximal levels 13.97, 16.09, and 12.68 ng/ml (not significantly different) and a mean area under the curve of 168.13, 207.64 and 227.71 ng/ml per hour on days 1, 7, and 14 (not statistically different). CONCLUSIONS These data indicate that vaginal absorption of progesterone is efficient. The lack of difference in the area under the curve for both doses suggests that the vaginal mucosa or the total surface area of the vagina may limit the absorption of progesterone from the vagina.
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Affiliation(s)
- D F Archer
- Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, USA
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Abstract
The PA Patch, a new multiple-antigen, predispensed patch testing device, was compared to the Finn Chamber in subjects with previous positive patch tests. After pressing the PA Patch well, the PA Patch performed as well as the Finn Chamber in nine subjects tested.
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Abstract
A blend of nylon fiber and silver-coated nylon fiber (the latter known as X-static) was used in these experiments. This fiber was bactericidal when bacteria were exposed to it directly or to an extract derived from its prior incubation in salt solution. At ambient temperatures, a rapid exponential decrease of survival occurred, usually after a delay of approximately 1 h. The rate of killing (decrease of survival) increased with an increase in X-static percentage of the fiber blend, temperature of fiber extraction, concentration of Tris buffer present during extraction, and temperature at which bacteria were exposed to the extract. When bacteria were exposed to the extract at 37 degrees C as opposed to ambient temperature, there was no delay in onset of killing. Escherichia coli was generally the indicator organism tested, but comparable results were also found for Pseudomonas, Klebsiella, Staphylococcus, and Streptococcus species. The rate of killing increased with increasing silver ion concentration of the fiber extract, as determined through atomic absorption spectrophotometry. The rate of killing was greater and the onset was earlier with an extract containing silver ions from fiber than with a salt solution containing the same concentration of silver ions from silver nitrate. Studies of the kinetics of ion release suggested that X-static may be an effective, sustained-release antibacterial agent.
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Abstract
A plasmid containing a herpes simplex virus type 1 (HSV-1) insert from strain KOS, prototypic coordinates 0.345 to 0.368 (3.45 kilobases) was mutagenized in vitro, and potential mutations were introduced into intact viral DNA by cotransfection. Functions normally associated with the glycoprotein gB are in the 1-9 complementation group, and the above coordinates include those that specify the gB glycoprotein gene. Following cotransfection, individual plaques were screened for temperature sensitivity (ts) of viral growth. A total of seven ts mutants was obtained, of which four were spurious mutations due to alterations outside the cloned sequences, presumably mediated by some aspect of the Ca-precipitation-cotransfection method. The remaining three did not complement known mutants of the 1-9 complementation group. These three mutants, along with tsJ12 (P.A. Schaffer, G.M. Aron, N. Biswal, and M. Benyesh-Melnick, 1973, Virology 52, 57-71) and tsJ33 (C.-T. Chu, D.S. Parris, R.A.F. Dixon, F.E. Farber, and P.A. Schaffer, 1979, Virology 98, 168-181), were physically located by marker-rescue experiments to three different restriction fragments between 0.345 to 0.368 map units. Sodium dodecyl sulfate-gel electrophoresis was used to analyze the glycoproteins synthesized during continuous or pulse-chase labeling protocols. All five mutants were found to synthesize a precursor of gB but did not accumulate mature gB during a pulse, a chase, or continuous labeling at the nonpermissive temperature.
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DeLuca N, Bzik DJ, Bond VC, Person S, Snipes W. Nucleotide sequences of herpes simplex virus type 1 (HSV-1) affecting virus entry, cell fusion, and production of glycoprotein gb (VP7). Virology 1982; 122:411-23. [PMID: 6293179 DOI: 10.1016/0042-6822(82)90240-9] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Choo SY, Vollherbst K, Keith A, Snipes W. Effects of adamantane derivatives on the stability and assembly of bacteriophage PM2. Can J Microbiol 1982; 28:897-900. [PMID: 7172140 DOI: 10.1139/m82-134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
1-Adamantanamine and several related compounds were tested for their effect on the lipid-containing bacteriophage PM2. 2-Adamantanol and 1-adamantane methanol were virucidal, while 1-adamantane acetic acid inhibited virus production in a highly pH-dependent manner.
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Keith AD, Arruda D, Snipes W, Frost P. The antiviral effectiveness of butylated hydroxytoluene on herpes cutaneous infections in hairless mice. Proc Soc Exp Biol Med 1982; 170:237-44. [PMID: 6178117 DOI: 10.3181/00379727-170-41425] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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17
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Babich MA, Coohill TP, Snipes W, Taylor WD. The effect of metabolic inhibitors on the large plaque effect with Herpes simplex virus. Photochem Photobiol 1981; 34:197-201. [PMID: 6267622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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18
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DeLuca N, Bzik D, Person S, Snipes W. Early events in herpes simplex virus type 1 infection: photosensitivity of fluorescein isothiocyanate-treated virions. Proc Natl Acad Sci U S A 1981; 78:912-6. [PMID: 6262783 PMCID: PMC319914 DOI: 10.1073/pnas.78.2.912] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Herpes simplex virus type 1 is photosensitized by treatment with fluorescein isothiocyante (FITC). The inactivation of FITC-treated virions upon subsequent exposure to light is inhibited by the presence of sodium azide, suggesting the involvement of singlet oxygen in the process. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed that treatment with FITC plus light induces crosslinks in viral envelope glycoproteins. Treatment of virions with high concentrations of FITC (50 micrograms/ml) plus light causes a reduction in the adsorption of the virus to monolayers of human embryonic lung cells. For lower concentrations of FITC (10 micrograms/ml) plus light, treated virions adsorb to the host cells, but remain sensitive to light until entry occurs. The loss of light sensitivity coincides with the development of resistance to antibodies. These results are most consistent with a mechanism of entry for herpes simplex virus involving fusion of the viral membrane with the plasma membrane of the host cell.
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Abstract
A new instrument has been developed and used to determine the effect of various materials on nail flexibility. It repeatedly flexes longitudinal nail sections through 90 degrees and records the number of flexions required to fracture each section. Immersion in water or a phospholipid-water preparation (PLW) greatly increases the flexibility of untreated and lipid extracted nails; immersion in mineral oil does not. Nail flexibility is directly related to the duration of their immersion in water. During water immersion, nail weight increases by 22% of its original weight within 2 h, and then decreases. The rapid increase in nail flexibility during water immersion is related to nail water content. It is possible to prolong the flexibility of previously hydrated nails by the application of PLW or mineral oil. PLW is more effective than water alone in prolonging flexibility of nails extracted with a mixture of acetone, water and acetic acid.
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Taylor WD, DeLuca N, Vollherbst K, Doman T, d'Amato T, Snipes W. Characteristics of a new bacteriophage, Psp231a, infecting Pseudomonas phaseolicola HB10Y. J Virol 1980; 35:918-23. [PMID: 7420544 PMCID: PMC288885 DOI: 10.1128/jvi.35.3.918-923.1980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Bacteriophage Psp231a infects Pseudomonas phaseolicola, strain HB10Y, which is the host cell for the enveloped bacteriophage phi 6. This paper describes the biophysical characteristics of Psp231a and the physical properties of its nucleic acid. In electron micrographs the virion appears as an icosahedral structure, approximately 55 nm in diameter, with a short tail. The virion density is 1.48 g/cm3 in CsCl, and the sedimentation coefficient is approximately 407S. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of 12 polypeptides ranging in molecular weight from 5,000 to 117,000. The nucleic acid of Psp231a is linear, double-stranded DNA of molecular weight 28 X 10(6). Its density in CsCl is 1.716 g/cm3, and its sedimentation coefficient in 3 M CsCl is 20.0S, corresponding to an S020,W of 34S.
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Abstract
The broadening of spin-label absorption lines resulting from spin-exchange reactions that occur during collision with paramagnetic Ni2+ is diminished when Ni2+ binds to phospholipid vesicles. Subsequent addition of non-paramagnetic ions that compete for binding sites releases Ni2+ into solution and restores the line-broadening. The concentrations of various ions required to achieve this effect was used to order the ions with respect to their binding to vesicles containing phosphatidylethanolamine and phosphatidylglycerol. The relative strengths of binding for those ions studied were: Ca2+ > Mg2+ > Zn2+ > Sr2+ > Ba2+. The spin-broadening assay was also used to study the effects of two proteins on the availability of Ni2+-binding sites on the vesicles. Ribonuclease, which is thought to associate electrostatically as an extrinsic protein on the surface of vesicles, completely blocked the Ni2+-binding sites at comparatively low protein concentrations. Quantitative considerations of these data suggest the possibility that Ni2+ may bind preferenetially to phosphatidylglycerol, and that these binding sites are aggregated in the ribonuclease-containing vesicles. In contract to ribonuclease, cytochrome c does not block Ni2+-bindings sites on the phospholipid vesicles, but rather contains sites of its own that bind Ni2+, both when the protein is in solution and when it is associated with the vesicles. These results are consistent with other studies which suggest that cytochrome c becomes partially embedded in membrane bilayers and associates with phospholipid molecules through hydrophobic interactions.
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Coohill TP, Babich MA, Taylor WD, Snipes W. Herpes simplex virus produces larger plaques when assayed on ultraviolet irradiated CV1 cells. Photochem Photobiol 1980; 32:97-8. [PMID: 6252567 DOI: 10.1111/j.1751-1097.1980.tb03992.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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24
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Coohill TP, Babich M, Taylor WD, Snipes W. A comparison of herpes simplex virus plaque development after viral treatment with anti-DNA or antilipid agents. Biophys J 1980; 30:517-21. [PMID: 6266532 PMCID: PMC1328754 DOI: 10.1016/s0006-3495(80)85111-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The plaque development of Herpes simplex virus type 1 (HSV) is slower for viruses treated with two anti-DNA agents: ultraviolet radiation (UV) or n-acetoxy-2-acetyl-aminofluorene. For HSV treated with three antimembrane agents--butylated hydroxytoluene, acridine plus near UV radiation, or ether--the plaque development time is the same as for untreated viruses. These differences hold even for viruses that survived treatment that lowered viability below the 1% level. Gamma ray inactivation of HSV produces no change in plaque development even though this agent is believed to preferentially affect viral DNA.
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Abstract
A spin-labeled virucidal agent was synthesized, purified, and tested for its activity against the enveloped bacterial virus phi6 and herpes simplex virus. This compound, designated BPN, inactivated greater than 99% of phi6 and herpes simplex virus in vitro at concentrations as low as 0.1 mM. Detailed studies were carried out on the mechanism of inactivation of phi6 by BPN. These studies revealed that treatment of phi6 by BPN specifically removes a single envelope protein that is considered to be responsible for adsorption of the virus to the host cell. Related experiments with the phi6 host, Pseudomonas phaseolicola strain HB10Y, showed that this organism is insensitive to the effects of BPN. The basis for the differential sensitivity of phi6 to BPN, in comparison to the host cell, was investigated by electron spin resonance techniques. It was found that, for phi6, HB10Y, and their extracted phospholipids, BPN is localized in the hydrocarbon zones of the membrane bilayer. However, in the case of phi6, the rotational mobility of BPN is much reduced in comparison to that in HB10Y and the phospholipid preparations. Furthermore, an Arrhenius plot of rotational correlation time (tau(c)) showed a marked discontinuity in slope at 31 degrees C in the case of phi6, but not for the other samples studied. This suggests a strong interaction between the phi6 envelope proteins and the lipid domains in which BPN is localized. Calculations based on the known lipid and protein composition of phi6 indicate that there is an absence of "free-lipid" pools in the viral envelope. It is suggested that BPN localizes in free-lipid pools of cell membranes, where its presence is of little or no consequence, but that in phi6 the BPN perturbs the hydrophobic interactions between phospholipids and proteins in the envelope.
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Abstract
Herpes simplex virus type 2 and simian virus 40 were rapidly inactivated by retinal at micromolar concentrations. Other fat-soluble vitamins, particularly vitamin A derivatives, were also active against herpes simplex virus type 2 and several lipid-containing bacteriophages.
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Snipes W, Keller G, Woog J, Vickroy T, Deering R, Keith A. Inactivation of lipid-containing viruses by hydrophobic photosensitizers and near-ultraviolet radiation. Photochem Photobiol 1979; 29:785-90. [PMID: 451016 DOI: 10.1111/j.1751-1097.1979.tb07767.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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29
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Sands J, Auperin D, Snipes W. Extreme sensitivity of enveloped viruses, including herpes simplex, to long-chain unsaturated monoglycerides and alcohols. Antimicrob Agents Chemother 1979; 15:67-73. [PMID: 218499 PMCID: PMC352602 DOI: 10.1128/aac.15.1.67] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Unsaturated monoglycerides and alcohols of chain lengths of 16 or 18 carbons were found to be extremely potent inactivators of two enveloped viruses, herpes simplex virus type 2 and bacteriophage phi6. The lipid-containing bacteriophage PM2 was also inactivated by some of these amphiphilic molecules. Treatment of herpes simplex virus type 2 with these compounds at concentrations as low as 0.2 muM reduced virus survival to 50% in 30 min, making these agents the most potent inactivators of herpes simplex viruses discovered that are not cytotoxic to mammalian cells. Detailed characterizations of the effects of unsaturated monoglycerides and alcohols on bacteriophages phi6 and PM2 showed that the inactivated phi6 virion remained nearly intact but that PM2 was almost completely disrupted by the inactivating treatment. Some of the compounds inactivate the viruses even at low temperature (0 degrees C). Excess amounts of diglycerides and phospholipids interfere with the inactivating abilities of some of the unsaturated monoglycerides and alcohols against phi6 and PM2. Our findings suggest that the unsaturated monoglycerides and some of the unsaturated alcohols should be further studied as potential antiviral agents, particularly for application to herpesvirus-infected areas of the skin and accessible epithelium.
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30
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Hammerstedt RH, Keith AD, Snipes W, Amann RP, Arruda D, Griel LC. Use of spin labels to evaluate effects of cold shock and osmolality on sperm. Biol Reprod 1978; 18:686-96. [PMID: 656535 DOI: 10.1095/biolreprod18.4.686] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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31
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Abstract
Two probes were synthesized which consist of fluorescent molecules conjugated to saturated hydrocarbon chains, 18 carbons long, to ensure their localization into cellular membranes. There is an overlap between the emission spectrum of one probe (donor) and the absorption spectrum of the other probe (acceptor). By the use of appropriate wavelengths it is possible to specifically excite the donor probe and record the fluorescence of the acceptor probe. Two cell populations, each labelled with one of the probes, were infected with a virus that causes cell fusion, mixed in equal proportions, and the fluorescence of the acceptor probe measured as a function of time after infection. An increase in fluorescence was observed beginning at the time of onset of cell fusion indicating a mixing of the fluorescent membrane molecules. An investigation of the distance dependence indicated that the increase in fluorescence was mainly due to resonance energy transfer and not to photon emission and reabsorption. Resonance energy transfer requires that the 2 probes be close together and that there be an overlap of the emission spectrum of the donor probe and the absorption spectrum of the acceptor probe. The possible application of this assay to other types of membrane fusion is noted.
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32
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Pollard EC, Snipes W. Absence of two radiation-induced repair processes in a marine pseudomonad. Photochem Photobiol 1977; 26:545-7. [PMID: 594181 DOI: 10.1111/j.1751-1097.1977.tb07528.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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33
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Abstract
Line broadening of spin label signals is treated in terms of concentration, viscosity, charge and temperature dependencies. Line broadening of spin label signals may be caused either by spin label interactions or by the interaction between a spin label and a second paramagnetic species. Line broadening has been related to collision frequency in the literature and is treated in that way here. Collision frequency is related to diffusion processes in a way that allows information to be obtained about the diffusion environment. Several potential spin label line-broadening agents are compared as to their effectiveness. Small polymer beads with graduated pore sizes are used to show that collisional broadening has a marked dependence on the long-range structure of the diffusion environment. Application of these results to biological diffusion processes is considered.
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Abstract
Inositol auxotrophs of yeast developing on isositol-deficient medium continue protein synthesis for 4-6 h, lose viability rapidly after 6 h, and show an increase in cytoplasmic viscosity as measured by spin label rotational motion. Cycloheximide prevents the rapid loss of cell viability, stops protein synthesis, and simultaneously prevents an increase in cytoplasmic viscosity. From these observations, we infer that intracellular translational diffusion is upset as a consequence of inositol starvation. Cell death may be caused by a modified intracellular diffusion environment.
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36
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Abstract
Water-soluble spin labels were used to study dimyristoyllecithin (DML) phospholipid multilayers. Previous studies report that there is a "bound" water region associated with dimyristoyllecithin containing about 10 molecules of water per phospholipid, a "trapped" water region located between the lamellae containing approximately 11 molecules per phospholipid, and a "ftion show that certain water-soluble spin-label mol-cules have their motional properties differentially modified by these three water environements. Furthermore, the labels also reveal the onset of lipid-phase transitions even though they have high water solubility. A phosphate-containing spin label demonstrated strong an isotropic motion in the lipid-water system above the phase transition but not below. The addition of cholesterol to the DML-water system removed the anisotropic motion of 2,2,6,6-tetramehtyl-4-phosphopiperidine-N-oxyl (Tempophosphate) and obscured the detection bound, trapped, and free water. In addition to the change-charge interactions between Tempophosphate and DML, two other spin labels were used both in the charged and uncharged states. 2,2,6,6-Tetramethyl-4-aminopiperidine-N-oxyl (Tempamine) in the charged state showed extremely strong anisotropic motion, presumably due to the interaction between the charged amine and the phosphate group of DML. When only partially charged, Tempamine showed much less anisotropic motion. PCA was analyzed at pH values where the carboxyl group was protonated and unprotonated. The resulting interaction was different at the two pH values. These water-soluble spin labels mimic ionic or nonionic solutes. Upon freezing, the spin labels are shown to be expelled from the ice regions into the remaining aqueous regions. The usefulness of this approach in studying solute behavior when freezing occurs and potential studies involving aqueous regions of cytoplasm are considered.
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37
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Snipes W, Person S, Keller G, Taylor W, Keith A. Inactivation of lipid-containing viruses by long-chain alcohols. Antimicrob Agents Chemother 1977; 11:98-104. [PMID: 189684 PMCID: PMC351925 DOI: 10.1128/aac.11.1.98] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This report describes the inactivation of lipid-containing viruses by several long-chain alcohols. A striking peak in antiviral activity was found for saturated alcohols having chain lengths from 10 to 14 carbons. Viruses having different membrane structure showed different susceptibilities to alcohols having different chain lengths and structural features. Decanol, dodecanol, and tetradecanol readily inactivated herpes simplex virus and the enveloped bacterial virus phi6. The lipid-containing virus PM2 was susceptible to decanol and dodecanol but comparatively unsusceptible to tetradecanol. The branched-chain alcohol phytol, a naturally occurring component of chlorophyll, was active against phi6 and herpes simplex virus but not against PM2. Polyoma virus and the bacteriophage phi23-1-a, which do not contain lipids, were not susceptible to inactivation by any of the alcohols tested. Experiments were also carried out to determine the effects of these compounds on cells. At 0.5 mM, decanol lysed human embryonic lung cells, erythrocytes, and the bacterial hosts for phi6 and PM2. Dodecanol, tetradecanol, and phytol at this concentration were less damaging to cells. At 0.05 mM, none of the alcohols caused observable cytopathic effects on human embryonic lung cells, although several of the alcohols at this concentration were active against herpes simplex virus. Our findings suggest that dodecanol, tetradecanol, and phytol may warrant further studies as potential antiviral agents, particularly for topical application to virus-infected areas of the skin.
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Krasin F, Person S, Snipes W, Benson B. Local effect for (5-3H)cytosine decays: production of a chemical product with possible mutagenic consequences. J Mol Biol 1976; 105:445-51. [PMID: 787538 DOI: 10.1016/0022-2836(76)90103-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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39
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Wanda P, Cupp J, Snipes W, Deith A, Rucinsky T, Polish L, Sands J. Inactivation of the enveloped bacteriophage phi6 by butylated hydroxytoluene and butylated hydroxyanisole. Antimicrob Agents Chemother 1976; 10:96-101. [PMID: 984760 PMCID: PMC429695 DOI: 10.1128/aac.10.1.96] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Butylated hydroxytoluene (BHT) is a potent inactivator of the enveloped bacterial virus ø6 at concentrations as low as 3 x 10(-5) M. The viral envelope is not removed by BHT treatment, in contrast to the effects of exposure to the detergent Triton X-100. BHT-treated viruses are morphologically indistinguishable from controls but are defective in their ability to attach to the host cell. Temperature at the time of exposure was found to be a crucial factor in the effectiveness of BHT against ø6. A precipitous drop in the degree of inactivation by 3 x 10(-5) M BHT occurred when the temperature was lowered from 20 to 15 C. Calcium ions were found to potentiate the effect of BHT, particularly at lower temperatures where BHT alone was relatively ineffective. Barium and strontium, but not magnesium, were also effective in enhancing the activity of BHT. A structurally related molecule, butylated hydroxyanisole (BHA), was also found to inactivate ø6 virus, but higher concentrations were required than with BHT. Both BHT and BHA are commonly used as food additives, have apparent low toxicity to humans and other animals, and are potentially useful as antiviral agents.
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40
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Henry SA, Keith AD, Snipes W. Changes in the restriction of molecular rotational diffusion of water-soluble spin labels during fatty acid starvation of yeast. Biophys J 1976; 16:641-53. [PMID: 179632 PMCID: PMC1334887 DOI: 10.1016/s0006-3495(76)85718-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Yeast mutants lacking fatty acid synthetase activity (fas-) die when deprived of saturated fatty acid under conditions which are otherwise growth-supporting. The spin label technique is used to show that restriction of molecular rotational diffusion of spin label molecules dissolved in aqueous zones increases several fold under conditions of fatty acid starvation while the apparent physical state of cellular hydrocarbon zones remains essentially unchanged. We focus attention on the cellular aqueous interior as the potential site of alteration under selective starvation conditions. Correspondences exist between restriction of molecular motion of water soluble spin labels dissolved in the cell and loss of cell viability. The correspondences to changes in the molecular motion of hydrocarbon soluble spin labels are much less or are not detectable.
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Hammerstedt RH, Amann RP, Rucinsky T, Morse PD, Lepock J, Snipes W, Keith AD. Use of spin labels and electron spin resonance spectroscopy to characterize membranes of bovine sperm: effect of butylated hydroxytoluene and cold shock. Biol Reprod 1976; 14:381-97. [PMID: 179626 DOI: 10.1095/biolreprod14.4.381] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Cupp J, Wanda P, Keith A, Snipes W. Inactivation of the lipid-containing bacteriophage PM2 by butylate hydroxytoluene. Antimicrob Agents Chemother 1975; 8:698-706. [PMID: 1211923 PMCID: PMC429451 DOI: 10.1128/aac.8.6.698] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Several factors have been investigated which are of significance in the inactivation of PM2, a lipid-containing bacterial virus, by butylated hydroxytoluene (BHT). Studies of the time dependence of inactivation during exposure to BHT showed that virus killing occurs rapidly, with the majority of the effect taking place in the first 5 min. The degree of inactivation is dependent upon the initial virus titer, the solvent from which BHT is added, and the presence of a variety of protective agents, including surfactants, bovine serum albumin, and bacterial cells. Sucrose gradient analysis of (32)P-labeled, BHT-treated virus was used to determine the degree to which the virion is disrupted by BHT. These experiments show that the (32)P-labeled molecules are converted into very slowly sedimentable material by BHT treatment, indicating complete destruction of the virus particle.
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Keith AD, Aloia RC, Lyons J, Snipes W, Pengelley ET. Spin label evidence for the role of lysoglycerophosphatides in cellular membranes of hibernating mammals. Biochim Biophys Acta 1975; 394:204-10. [PMID: 166691 DOI: 10.1016/0005-2736(75)90258-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The phospholipid composition of ground squirrel heart muscle changes during hibernation: more lysoglycerophosphatides are found in the hibernating state than in the active state. Phase transitions inferred from spin label motion occur in the usual manner typical of mammalian mitochondria for the mitochondria and mitochondrial lipids from active squirrels. However, a conspicuous absence of a spin label-detectable phase transition is observed in equivalent preparations from hibernating animals. The addition of lysolecithin to preparations from active squirrels removes the break and induces a straight line in the Arrhenius plot. The lack of a spin label-detectable phase transition in hibernating animals, therefore, is attributed to an increased content of lysoglycerophosphatides present in the phospholipids during hibernation.
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Cupp J, Klymkowski M, Sands J, Keith A, Snipes W. Effect of lipid alkyl chain perturbations on the assembly of bacteriophage PM2. Biochim Biophys Acta 1975; 389:345-57. [PMID: 166676 DOI: 10.1016/0005-2736(75)90327-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The lipid-containing bacteriophage PM2 can produce infectious virus in cultures infected at temperatures up to 31.5 degrees C, but not at 34 degrees C. Its host, Pseudomonas BAL-31, grows at 34 degrees C and cultures infected at that temperature undergo lysis. Sucrose-gradient analysis shows that 34 degrees C lysates contain no PM2-like particles. Temperature-shift experiments establish that the thermally sensitive process is late in infection when virus assembly is taking place. Adamantanone, a small hydrophobic molecule that perturbs membrane hydrocarbon zones, prevents the production of infective virus. Concentrations which prevent virus production have no effect on host-cell growth or stability of mature virions. Adamantanone exerts its effects late in the infectious cycle, and lysates amde in its presence contain no PM2-like particles. These experiments, carried out at 25 degrees C, indicate that adamantanone prevents the assembly of stable PM2 virus. Spin-label studies suggest that the lipid alkyl chains of the host-cell membrane are in an "ordered" state at temperatures below about 33 degrees C and undergo a transition to a "disordered" state above that temperature. Furthermore, the addition of adamantanone perturbs the hydrocarbon zones, producing a greater degree of disorder even below 25 degrees C. Our findings suggest that the cell membrane can function and grow with the lipid alkyl chains in either the "ordered" or "disordered" state, but that the "ordered" state must be maintanined for PM2 assembly to occur.
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48
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Abstract
Butylated hydroxytoluene (BHT) is widely used as a food preservative for its antioxidizing property. This small, hydrophobic molecule has been found to be a potent inactivator of lipid-containing mammalian and bacterial viruses.
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Sands JA, Cupp J, Keith A, Snipes W. Temperature sensitivity of the assembly process of the enveloped bacteriophage phi6. Biochim Biophys Acta 1974; 373:277-85. [PMID: 4371873 DOI: 10.1016/0005-2736(74)90151-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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50
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Person S, McCloskey JA, Snipes W, Bockrath RC. Ultraviolet mutagenesis and its repair in an Escherichia coli strain containing a nonsense codon. Genetics 1974; 78:1035-49. [PMID: 4616874 PMCID: PMC1213237 DOI: 10.1093/genetics/78.4.1035] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Ultraviolet mutagenesis and its repair were studied mainly in WU36-10-89, a uvr(-) strain of Escherichia coli containing a UAG mutation in a gene for leucine biosynthesis. Following ultraviolet (UV) irradiation revertants appearing with or without direct photoreactivation (PR) were classified according to the presence and type of suppressor they contained. We find UV mutation production to be quite specific. An analysis of revertants produced by UV indicates they are formed mainly from GC --> AT and that the miscoding is due to a cytosine residue at the site of mutation in a cytosine-thymine (CT) dimer. We propose that the dimer serves as template during some aspects of repair replication and at the time of replication the C in the dimer directs the insertion of A in the complementary strand. We also note that C --> A and T -->G changes caused by a CT dimer occur much less frequently.
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