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Lewis S, Downing C, Hayre CM. Concept analysis of 'Facilitating a transformative radiation protection environment'. Radiography (Lond) 2024; 30:827-833. [PMID: 38552562 DOI: 10.1016/j.radi.2024.03.007] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/22/2024] [Accepted: 03/17/2024] [Indexed: 05/18/2024]
Abstract
INTRODUCTION Suboptimal radiation protection evidenced in literature necessitated the development of a theory to optimise radiation protection. To develop a theory, concept analysis of the central concept guiding the theory is required to provide explicit theoretical and operational definitions. This article presents the concept analysis of the central concept of 'facilitating a transformative radiation protection environment' used to develop a theory to optimise radiation protection. METHODS The study used Walker and Avant's concept analysis process of selecting a concept, determining the aims and purpose of analysis, identifying all uses of the concept, and determining the defining attributes by identifying a model case, a borderline case and a contrary case. RESULTS The central concept was dissected into the individual concepts of facilitating, transformative, radiation, protection, and environment to enhance the definition and conceptual meaning of the central concept. The essential and related attributes of the individual concepts informed the summative definition of the central concept, and a model, borderline and contrary case contributed to the conceptual meaning. CONCLUSION The summative definition of the central concept of "facilitating a transformative radiation protection environment" was determined to be through the essential attributes of help, process, change, X-rays, keeping safe considering the benefits versus risks of ionising radiation exposure and the total internal, external context within which persons exist and the related attributes. IMPLICATIONS FOR PRACTICE Explored extensively in nursing literature, concept analyses in radiography are limited. Therefore, this article articulates the process of concept analysis and its use in radiography. Concept analysis provides a systematic process to analyse concepts often assumed to be understood, highlighting its importance in radiography literature and to educational praxis.
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Affiliation(s)
- S Lewis
- Department of Medical Imaging and Radiation Sciences, Faculty of Health Sciences, University of Johannesburg, South Africa.
| | - C Downing
- Department of Nursing, Faculty of Health Sciences, University of Johannesburg, 6105D, West Wing North, John Orr Building, Doornfontein Campus, South Africa.
| | - C M Hayre
- School of Dentistry and Health Sciences, University of Exeter, College of Medicine and Health, Room 1.32, South Cloisters, UK.
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Downing C, Redelius K, Nordin-Bates SM. An Index Approach to Early Specialization Measurement: An Exploratory Study. Front Psychol 2020; 11:999. [PMID: 32528375 PMCID: PMC7265620 DOI: 10.3389/fpsyg.2020.00999] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 04/22/2020] [Indexed: 11/13/2022] Open
Abstract
The methodological underpinnings of studies into early specialization have recently been critiqued. Previous researchers have commented on the variety of, and over-simplified, methods used to capture early specialization. This exploratory study, therefore, suggests a new direction for how early specialization can be conceptualized and measured. We aim to create an index approach whereby early specialization is measured as a continuous variable, in line with commonly used definitions. The continuous variable for degrees of early specialization is calculated from a questionnaire which captures the four key components of early specialization; (1) intensity, (2) year-round training, (3) single sport, and (4) commencing age 12 or younger. The proposed index approach is illustrated in a sample of 290 Swedish aesthetic performers aged 12-20 years (M = 15.88), whose descriptive statistics are used to discuss the suitability and usability of the measure. The proposed index approach functions as a guideline to future researchers. We hope that introducing a new index approach we will encourage further discussion around the measurement of early specialization. Additionally, we hope to pave the way for future research to explore more complex research questions.
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Affiliation(s)
| | - Karin Redelius
- Swedish School of Sport and Health Sciences, Stockholm, Sweden
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Abstract
State-of-the-art applications of nanomedicine have the potential to revolutionize the diagnosis, prevention, and treatment of a range of conditions and diseases affecting women’s health. In this review, we provide a synopsis of potential applications of nanomedicine in some of the most dominant fields of women’s health: mental health, sexual health, reproductive medicine, oncology, menopause-related conditions and dementia. We explore published studies arising from in vitro and in vivo experiments, and clinical trials where available, to reveal novel and highly promising therapeutic applications of nanomedicine in these fields. For the first time, we summarize the growing body of evidence relating to the use of nanomaterials as experimental tools for the detection, prevention, and treatment of significant diseases and conditions across the life course of a cisgender woman, from puberty to menopause; revealing the far-reaching and desirable theoretical impact of nanomedicine across different medical disciplines. We also present an overview of potential concerns regarding the therapeutic applications of nanomedicine and the factors currently restricting the growth of applied nanomedicine.
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Affiliation(s)
- Oliver Lloyd-Parry
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
| | - Charlotte Downing
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
| | - Eisa Aleisaei
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
| | - Celine Jones
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
| | - Kevin Coward
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
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Downing C, Hudson S, Goodell L, Stage V. Comparison of Parent and Child Rankings of Fruit and Vegetable Liking to Assess Parent Accuracy as Proxy Reporters. J Acad Nutr Diet 2016. [DOI: 10.1016/j.jand.2016.06.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Seral-Ascaso A, Metel S, Pokle A, Backes C, Zhang CJ, Nerl HC, Rode K, Berner NC, Downing C, McEvoy N, Muñoz E, Harvey A, Gholamvand Z, Duesberg GS, Coleman JN, Nicolosi V. Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes. Nanoscale 2016; 8:11698-11706. [PMID: 27221399 DOI: 10.1039/c6nr01663d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.
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Affiliation(s)
- A Seral-Ascaso
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - S Metel
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - A Pokle
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - C Backes
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - C J Zhang
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - H C Nerl
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - K Rode
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - N C Berner
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - C Downing
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland.
| | - N McEvoy
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - E Muñoz
- Instituto de Carboquímica ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - A Harvey
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Z Gholamvand
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - G S Duesberg
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - J N Coleman
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - V Nicolosi
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
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Nguyen HP, Stiegel KR, Downing C, Stiegel KR. Recent approval of Xerese in Canada: 5% acyclovir and 1% hydrocortisone topical cream in the treatment of herpes labialis. Skin Therapy Lett 2014; 19:5-8. [PMID: 25188362] [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] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Herpes labialis is a frequently occurring viral infection of the lips and oral mucosa. Recurring lesions are induced by viral reactivation and replication, but the symptoms leading to morbidity, such as pain and inflammation, are immune-mediated. The introduction of 5% acyclovir/1% hydrocortisone in a topical cream (Xerese™) represents a therapeutic strategy directed at both of these pathogenic processes. Applied at the onset of prodromal symptoms, this combination treatment has a good safety profile and is more effective in reducing healing time than antiviral or anti-inflammatory agents alone. Although it was US FDA-approved for herpes labialis in 2009, Xerese™ has only recently been approved for use in Canada in October 2013. Herein, we review the basic science and clinical studies that support the efficacy of this topical combination acyclovir-hydrocortisone product in treating herpes labialis and examine its safety profile, as well as touch upon other therapies that have been shown to be effective in treating this common viral condition.
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Affiliation(s)
- H P Nguyen
- Department of Dermatology, Baylor College of Medicine, Houston, TX, USA; Department of Dermatology, University of Texas Medical School at Houston, Houston, TX, USA; Center for Clinical Studies, Houston, TX, USA
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Kayode O, Pabla G, Downing C, Speakman J. Documentation of do not attempt cardiopulmonary resuscitation (DNACPR) orders – do electronic DNACPR order (eDNACPR) forms make a clinical difference over standardised paper DNACPR order (sDNACPR) forms? BMJ Support Palliat Care 2012. [DOI: 10.1136/bmjspcare-2012-000250.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Affiliation(s)
| | - C. Downing
- Department of Materials; University of Oxford; Parks Road; Oxford; OX1 3PH; UK
| | - K. L. Moore
- Department of Materials; University of Oxford; Parks Road; Oxford; OX1 3PH; UK
| | - C. R. M. Grovenor
- Department of Materials; University of Oxford; Parks Road; Oxford; OX1 3PH; UK
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Christien F, Downing C, Moore KL, Grovenor CRM. Quantification of grain boundary equilibrium segregation by NanoSIMS analysis of bulk samples. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.4806] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - C. Downing
- Department of Materials; University of Oxford; Parks Road; OX1 3PH; Oxford; UK
| | - K. L. Moore
- Department of Materials; University of Oxford; Parks Road; OX1 3PH; Oxford; UK
| | - C. R. M. Grovenor
- Department of Materials; University of Oxford; Parks Road; OX1 3PH; Oxford; UK
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McKenna DS, Ventolini G, Neiger R, Downing C. Gender-related differences in fetal heart rate during first trimester. Fetal Diagn Ther 2006; 21:144-7. [PMID: 16354993 DOI: 10.1159/000089065] [Citation(s) in RCA: 19] [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] [Received: 10/28/2004] [Accepted: 02/21/2005] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Many expecting parents wish to ascertain fetal gender early in pregnancy. Our goal was to determine whether fetal heart rate (FHR) of males and females during the first trimester is significantly different. MATERIALS AND METHODS From November 1997 to February 2003 we enrolled pregnant women with singleton gestations who underwent obstetric sonography at less than 14 weeks of gestational age. Indications for the sonographic study included first-trimester bleeding, uncertain gestational dating, poor obstetrical history, and aneuploidy screening by nuchal translucency. The sonographic studies were performed by a single sonographer and reviewed by the first author. The FHR was determined by m-mode. All subjects underwent second-trimester sonography at 18.0-24.0 weeks' gestation by the same team, and fetal gender was recorded. Multiple gestations, miscarriages and pregnancies with uncertain fetal gender were excluded. Sonographically assigned fetal gender was confirmed at delivery. RESULTS Of the 966 first-trimester studies performed, 477 met the inclusion criteria. Of these, 244 (51%) were female and 233 (49%) were males. There were no statistical differences in mean maternal age, gravidity, parity, and mean gestational age at the time of the first study (9.0 +/- 2.3 weeks for female fetuses and 9.0 +/- 2.3 weeks for males, p = 0.7). The average female FHR was 151.7 +/- 22.7 bpm and male FHR was154.9 +/- 22.8 bpm (p = 0.13). DISCUSSION Contrary to beliefs commonly held by many pregnant women and their families, there are no significant differences between male and female FHR during the first trimester.
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Affiliation(s)
- D S McKenna
- Department of Obstetrics and Gynecology, Wright State University, Dayton, OH 45409-2902, USA
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Abstract
Genetic influences on the psychomotor stimulant effect of ethanol may be a key feature of abuse liability. While earlier work has shown the activational effects of ethanol to be under the influence of a relatively uncomplicated additive genetic system, preliminary data from our laboratory suggested the possibility of nonadditive genetic variance. In the present study, a full Mendelian cross was conducted to further characterize gene action and search for quantitative trait loci (QTL) influencing the psychomotor stimulant properties of ethanol. We tested 3062 mice of the six Mendelian cross genotypes (P1, P2, F1, F2, BC1 and BC2) derived from a cross between the C57BL/6J (B6) and C3H/HeJ (C3H) inbred strains of mice. On day 1, mice were injected with saline, put in a holding cage for 5 min, then placed in an activity monitor for 5 min. On day 2, mice were injected with 1.5 g/kg ethanol, and activity again monitored for 5 min. Analysis showed the expected activation in the C3H strain and little activation in the B6 strain, with no effect of sex. Biometrical genetic analysis showed a best-fit model that included the mean (m), additive effect (a), and an epistatic parameter (i = homozygote by homozygote interaction). Analysis showed good evidence for QTL on chromosomes 1 (logarithm of odds (LOD) 3.4-7.5, 88-100 cM), 6 (LOD 9.1-10.4, 46-50 cM) and 15 (LOD 7.3-8.8, 28-32 cM). While the regions on chromosomes 1 and 6 have previously been implicated in several different ethanol-related phenotypes, this is the first report of a QTL influencing the psychomotor stimulant properties of ethanol on chromosome 15. Other studies have identified QTL in this region of chromosome 15 mediating locomotor activation caused by other psychostimulants, including cocaine, amphetamine and phencyclidine.
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Affiliation(s)
- C Downing
- Psychology Department, University at Albany, State University of New York, USA.
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Abstract
We investigated the randomness and uniqueness of human iris patterns by mathematically comparing 2.3 million different pairs of eye images. The phase structure of each iris pattern was extracted by demodulation with quadrature wavelets spanning several scales of analysis. The resulting distribution of phase sequence variation among different eyes was precisely binomial, revealing 244 independent degrees of freedom. This amount of statistical variability corresponds to an entropy (information density) of about 3.2 bits mm(-2) over the iris. It implies that the probability of two different irides agreeing by chance in more than 70% of their phase sequence is about one in 7 billion. We also compared images of genetically identical irides, from the left and right eyes of 324 persons, and from monozygotic twins. Their relative phase sequence variation generated the same statistical distribution as did unrelated eyes. This indicates that apart from overall form and colour, iris patterns are determined epigenetically by random events in the morphogenesis of this tissue. The resulting diversity, and the combinatorial complexity created by so many dimensions of random variation, mean that the failure of a simple test of statistical independence performed on iris patterns can serve as a reliable rapid basis for automatic personal identification.
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Affiliation(s)
- J Daugman
- University of Cambridge, Computer Laboratory, Cambridge CB2 3QG, UK.
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Abstract
We present a new approach to the cocktail party problem that uses a cortronic artificial neural network architecture (Hecht-Nielsen, 1998) as the front end of a speech processing system. Our approach is novel in three important respects. First, our method assumes and exploits detailed knowledge of the signals we wish to attend to in the cocktail party environment. Second, our goal is to provide preprocessing in advance of a pattern recognition system rather than to separate one or more of the mixed sources explicitly. Third, the neural network model we employ is more biologically feasible than are most other approaches to the cocktail party problem. Although the focus here is on the cocktail party problem, the method presented in this study can be applied to other areas of information processing.
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Abstract
INTRODUCTION Historically our program has used the practice of hot-loading at scenes as a time-saving measure. This practice potentially exposes patients and health care personnel to a variety of risks. Currently no data exist supporting the use of hot-loading as a time-saving technique. We prospectively studied load times and scene times for both hot- and cold-loading methods. METHODS Hot- or cold-loading methods were randomized according to odd or even days of the month for scene runs. Both loading times and total scene times were recorded. An ANOVA was used to compare the times, taking into consideration the aircraft in use (BO 105 or BK 117). RESULTS A total of 104 flights were entered into the study. For loading time, hot-loading showed a statistically significant difference (F [1,100] = 112.84, P = 0.000). Means for hot- and cold-loading times are 3.071 and 5.033 minutes, respectively. The interaction effect of aircraft and loading method also was significant (F [1,100] = 4.637, P = 0.034). The BO 105 (on high skids) was slower to hot-load. In contrast, the BK 117 (additional pretakeoff system checks) was slower to cold-load. The type of aircraft alone showed no effect on loading time. Total scene times were evaluated using the same procedures. A statistically significant difference also was found for the effect of hot-loading on total scene time (F [1,100] = 11.391, P = 0.001). Means for hot and cold total scene times are 10.54 and 13.615 minutes, respectively. CONCLUSION Hot-loading does decrease our program's overall scene times. The clinical significance of this procedure was not evaluated.
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Affiliation(s)
- D Deimling
- University Air Care, University Hospital, Cincinnati, OH 45267-0736, USA
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Abstract
Both maternal and fetal genetic factors influence variations in response to prenatal ethanol exposure. To assess the effect of maternal genotype on the incidence of ethanol teratogenesis, a reciprocal cross study was conducted in an animal mode using the relatively susceptible C57BL/6J (B6) and the relatively resistant DBA/2J (D2) inbred mice. This mating pattern produced four embryonic genotypes: true-bred B6B6 and D2D2 litters and hybrid B6D2 and D2B6 litters. To examine the role of maternal egg cytoplasm as the source of variation that could account for a maternal effect, B6D2 and D2B6 F1 females were mated back to B6 males, which produced two additional embryonic genotypes: B6D2.B6 and D2B6.B6. Dams were intubated with either 5.8 g/kg of ethanol or an isocaloric amount of maltose-dextrin on day 9 of pregnancy. On day 18 of pregnancy, dams were sacrificed, fetuses were removed, weighed, sexed, and examined for gross morphological malformations. Every other fetus within a litter was prepared for either skeletal or soft tissue analysis. Results showed a higher rate of teratogenesis in the B6D2 group compared to the genetically similar D2B6 group, which indicates an influence of maternal genotype on susceptibility to ethanol teratogenesis. The percentage of affected male and female fetuses did not differ, which suggests that sex-linked factors are not responsible for the maternal effect. The backcross B6D2.B6 and D2B6.B6 litters did not differ significantly for any measure of teratogenesis, suggesting that differences in maternally transmitted cytoplasmic material are not the cause of the maternal effect. Factors that could account for the maternal effect are differences in the maternal uterine environment and genomic imprinting. Separating maternal from fetal-mediated mechanisms responsible for susceptibility to ethanol teratogenesis is needed for identifying mothers and infants at risk.
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Affiliation(s)
- C Downing
- Psychology Department, State University of New York at Albany 12222, USA.
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Abstract
Polyclonal antibodies raised in a rabbit against avian atrial natriuretic peptide (ANP) were used to investigate the role of endogenous plasma ANP in the control of salt gland function of conscious, saltwater-adapted Pekin ducks. Salt gland secretion was initiated and maintained either by a hypervolemic (290 mosmol/kg NaCl i.v. at 2 ml/min) or hyperosmotic (1,000 mosmol/kg NaCl i.v. at 0.4 ml/min) stimulus. Both experimental conditions caused significant elevations in endogenous plasma ANP concentrations. At steady states of secretion driven by hypervolemia, the administration of ANP antiserum (anti-ANP), which reduced plasma ANP concentrations by 90%, caused an immediate 30% reduction in fluid secretion rate and sodium excretion that lasted for 20-30 min. The activity of salt glands driven by hyperosmolality was not changed by anti-ANP. The results show that the high circulating concentrations of endogenous ANP associated with conditions of sustained volume expansion promote salt gland secretion.
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Affiliation(s)
- D A Gray
- Department of Physiology, University of the Witwatersrand, Johannesburg, South Africa
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Schorah CJ, Downing C, Piripitsi A, Gallivan L, Al-Hazaa AH, Sanderson MJ, Bodenham A. Total vitamin C, ascorbic acid, and dehydroascorbic acid concentrations in plasma of critically ill patients. Am J Clin Nutr 1996; 63:760-5. [PMID: 8615361 DOI: 10.1093/ajcn/63.5.760] [Citation(s) in RCA: 204] [Impact Index Per Article: 7.3] [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: 01/31/2023] Open
Abstract
Plasma concentrations of the antioxidant vitamin ascorbic acid were measured by high-performance liquid chromatography in critically ill patients in whom the excessive generation of reactive oxygen species could compromise antioxidant defense mechanisms. Median concentrations of both total vitamin C (ascorbic acid and dehydroascorbic acid) and ascorbic acid in these patients were < 25% (P < 0.001) of the values found in healthy control subjects and in subjects in two other disease groups (diabetes, gastritis) in which reactive oxygen species are reported to be increased. The low values could not be explained by age, sex, intake, or treatment differences, but were associated with the severity of the illness and were not prevented by the use of parenteral nutrition containing ascorbic acid. In addition, the vitamin was less stable in blood samples taken from critically ill patients than in similar samples from subjects in the other groups. The findings indicate that antioxidant defenses could be considerably compromised in these very sick patients. If this reduces the patient's capacity to scavenge reactive species, then the potential of these species to damage DNA and lipid membranes could be increased and compromise recovery.
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Affiliation(s)
- C J Schorah
- Division of Clinical Sciences, University of Leeds, United Kingdom
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Abstract
The study objective was to determine if pulse oximetry readings obtained during helicopter transport were indicative of subsequent arterial blood-gas measured saturations. A prospective study design was chosen. Data were gathered on a convenience sample of patients 18 years and older not under cardiopulmonary resuscitation; 101 patients were used for the study. Pulse oximeter readings of oxygen saturation and heart rate were recorded along with simultaneous vital signs. Arterial saturation in blood gases drawn in the emergency department were added to the patient record. Improper functioning of the pulse oximeter was recorded on 10 (9.9%) of the patients. No correlation was found between the probe type and the documented problems (PHI = 0.009). The pulse oximeter saturation readings were not significantly different from arterial saturation in blood gases when compared by paired samples t-test (t = 0.880, p = 0.383). There was also no significant difference between the patient's heart rate sensed by the pulse oximeter and the simultaneous palpated pulse rate. Percent saturation readings by repeated measures were statistically different (p < 0.05) showing a minimal improvement in saturation over time. Based on this study's findings, the authors feel the pulse oximeter can be a valuable adjunct to patient care during helicopter transport.
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Nelson D, Azari M, Brown R, Burhop K, Bush S, Catarello J, Chuang H, Downing C, Estep T, Loewen A. Preparation and characterization of diaspirin cross-linked hemoglobin solutions for preclinical studies. Biomater Artif Cells Immobilization Biotechnol 1992; 20:423-7. [PMID: 1391458 DOI: 10.3109/10731199209119662] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
During 1990 and 1991 the capability for repetitive, consecutive production of DCLHb solution to meet a rigorous and complete set of product criteria was demonstrated. In addition, through periodic monitoring of product stored under controlled conditions, the stability of all lots of DCLHb solution during frozen storage was demonstrated for more than a year. In this way, assurance was provided that the DCLHb solution used in preclinical testing met all product criteria throughout the biological testing period.
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Affiliation(s)
- D Nelson
- Blood Substitutes Program, Baxter Healthcare Corporation, Los Angeles, CA
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Downing C, Berkowitz R. Chemical dependency or Munchausen's syndrome. J Am Dent Assoc 1986; 112:806, 808. [PMID: 3458793 DOI: 10.14219/jada.archive.1986.0108] [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: 01/05/2023]
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