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Mahomed-Asmail F, Metcalfe L, Graham MA, Eccles R. Exploring facilitators and barriers for delivering person-centered care in a socio-economically diverse context: Perspectives of speech-language pathologists and audiologists. Patient Educ Couns 2024; 124:108250. [PMID: 38503035 DOI: 10.1016/j.pec.2024.108250] [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] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 01/31/2024] [Accepted: 03/11/2024] [Indexed: 03/21/2024]
Abstract
OBJECTIVE The study aimed to explore facilitators and barriers in delivering person-centered care from the perspective of speech-language pathologists and audiologists in a socio- economically diverse workplace across micro, meso, and macro levels. METHOD A national cross-sectional e-survey was conducted among pooled speech-language pathologists and/or audiologists from South Africa. The e-survey included quantitative components to describe participant demographics which was analysed using descriptive and inferential statistics. The qualitative data was analyzed using metaphor and thematic analysis approaches to describe respondents' perspectives of barriers and facilitators in delivering person-centered care. RESULTS The e-survey was completed by 63 clinicians (36.5% Audiologists; 36.5% Speech-Language Therapists; 27.0% dually qualified Speech-Language Therapists and Audiologists) mostly between the ages of 26 to 35 years old (33.3%). Respondents were working in various settings including the public sector (41.3%), private sector (44.4%) and in academia (14.3%). Facilitators and barriers were identified within all three systems (macro, meso and micro). The metaphor analysis resulted in six categories: uncertainty of Person centered care; its essential nature; associated challenges; relational aspect; analogies referring to animals; and food-related analogies. Thematic analysis of open-ended questions revealed five barriers, with three relating to micro systems; i) clinician factors, ii) client factors, iii) clinician and client interaction, and two related to factors within the meso system; iv) resources, and v) workplace. Only two themes were identified as facilitators towards PCC, clinician factors (mirco) and workplace factors (meso).' CONCLUSIONS Insights gained from exploring Speech-Language Pathologists' and Audiologists' perceptions of implementing PCC in a socio-economically diverse setting highlight the need to address contextual (meso and macro systems) and personal (micro system) factors to promote and deliver PCC effectively. Notably, for the public sector, resources emerged as a major concern and barrier on the macro system level. Despite these challenges, the investigation revealed two noteworthy facilitators: clinician factors, at the micro level, and workplace factors, at the meso level. This nuanced understanding emphasizes the necessity of tailored interventions targeting both individual and systemic aspects to enhance the successful implementation of person-centered care. PRACTICAL IMPLICATIONS Strategies should focus on enhancing clinicians' communication skills, collaboration, and teamwork, as well as addressing resource limitations through the adaptation of tools and implementation of PCC ISO standards.
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Affiliation(s)
- Faheema Mahomed-Asmail
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa.
| | - Louise Metcalfe
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Marien Alet Graham
- Department of Science, Mathematics and Technology Education, University of Pretoria, Pretoria, South Africa
| | - Renata Eccles
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
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Mahomed-Asmail F, Nicholson N, Metcalfe L, Rutherford C, Alet Graham M, Watson V, Regan C, Hussain S. Enhancing audiology students' understanding of person-centered care: insights from an multi-national virtual student conference. Int J Audiol 2024:1-7. [PMID: 38701177 DOI: 10.1080/14992027.2024.2344097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 04/11/2024] [Indexed: 05/05/2024]
Abstract
OBJECTIVE This project sought to investigate the impact of a multi-national peer learning initiative in facilitating a student-led conference on person-centred care (PCC). The primary objective was to assess students' comprehension of PCC elements before and after engaging in the opportunity, with a concurrent evaluation of the efficacy of the opportunity. DESIGN A mixed-methods study protocol was followed. Following the conference, participants completed a four-part survey including (a) demographics, (b) retrospective pre-post Likert scale, (c) Likert rating of conference experience and (d) five open-ended questions. STUDY SAMPLE One hundred and four participants (92.4% female) with a mean age of 21 years (0.07 SD) participated in the study. RESULTS A significant difference in awareness pre-post conference was demonstrated across all topics (WSR, p < 0.001) with participants satisfied with the conference. Qualitative analysis revealed three main themes: (a) application of PCC; (b) perspectives of PCC; and () barriers to PCC; with nine sub-themes. CONCLUSION The conference was beneficial in enhancing students' awareness of topics and principles of PCC. Innovative pedagogical approaches should be considered in order to enhance healthcare education allowing future clinicians to better meet the dynamic needs of their clients.
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Affiliation(s)
- Faheema Mahomed-Asmail
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | | | - Louise Metcalfe
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | | | - Marien Alet Graham
- Department of Early Childhood Education, University of Pretoria, Pretoria, South Africa
| | - Victoria Watson
- School of Engineering, University of Southampton, Southampton, United Kingdom
| | - Catherine Regan
- Department of Audiology, Nova Southeastern University, Florida, USA
| | - Saira Hussain
- Department of Audiology, Aston University, Birmingham, United Kingdom
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Mahomed-Asmail F, Metcalfe L, Graham MA, Joubert K, Hlayisi VG, Swanepoel DW. Person centered care: preference, experience and predictors in speech-language pathology and audiology students. Speech, Language and Hearing 2023. [DOI: 10.1080/2050571x.2023.2173890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- Faheema Mahomed-Asmail
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Louise Metcalfe
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Marien Alet Graham
- Department of Science, Mathematics and Technology Education, University of Pretoria, Pretoria, South Africa
| | - Karin Joubert
- Department of Audiology, University of the Witwatersrand, Johannesburg, South Africa
- Ndlovu Wits Audiology Clinic, Dennilton, South Africa
| | - Vera-Genevey Hlayisi
- Division of Communication Science and Disorders, Department of Health and Rehabilitation Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - De Wet Swanepoel
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
- Ear Science Institute Australia, Subiaco, Australia
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine, Aurora, Colorado, USA
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Affiliation(s)
- A. C. Migliorisi
- Veterinary Teaching Hospital Colorado State University Fort Collins Colorado USA
| | - L. Metcalfe
- Rood and Riddle Equine Hospital Lexington Kentucky USA
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Lakeland T, Samsudeen A, Metcalfe L, Govindaraju H, Turner N. Exploring how compartment‐specific changes in NAD biosynthesis influence the response to endurance training. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.05062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lakeland TV, Samsudeen A, Metcalfe L, Govindaraju H, Turner N. Exploring How Compartment‐specific Changes in NAD Biosynthesis Influence the Response to Endurance Training. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.02831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Affiliation(s)
- Vincent Deary
- Senior Lecturer in Health Psychology, Northumbria University
| | - Louise Metcalfe
- Assistant Psychologist, Northumberland Tyne and Wear NHS Foundation Trust
| | - Janet A Wilson
- Professor of Otolaryngology Head and Neck Surgery, Newcastle University and Department of Otolaryngology Head and Neck Surgery, Freeman Hospital, Newcastle upon Tyne NE7 7DN
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Milliken LA, Cussler E, Zeller RA, Choi JE, Metcalfe L, Going SB, Lohman TG. Changes in soft tissue composition are the primary predictors of 4-year bone mineral density changes in postmenopausal women. Osteoporos Int 2009; 20:347-54. [PMID: 18607670 DOI: 10.1007/s00198-008-0664-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 05/13/2008] [Indexed: 10/21/2022]
Abstract
UNLABELLED Changes in body weight influence bone mineral density, but the role of body composition is not clear in postmenopausal women. Body weight and soft tissue composition predicted bone changes independent of calcium supplementation and exercise frequency, indicating that soft tissue composition should be measured in clinical trials. INTRODUCTION The purpose of this study was to examine the relationship between changes in body weight and composition and changes in 4-year bone mineral density (BMD) after accounting for age, 4-year exercise frequency (EX), and 4-year calcium supplement intake (CA) in postmenopausal women with and without hormone therapy (HT). METHODS Postmenopausal women (aged 40-65 years) either using HT (for 1-3.9 years) or not using HT (for > or =1 year) were recruited to the study. EX and CA was monitored throughout the study and 167 women completed 4 years. BMD and soft tissue composition measurements were made using dual-energy X-ray absorptiometry. Regression was used to predict 4-year BMD changes from EX, CA, age, baseline and 4-year changes in body weight and composition. HT users (n = 115, 55.3 +/- 4.3 years) and non-users (n = 52, 57.5 +/- 4.7 years) were analyzed separately. RESULTS The models predicting regional BMD changes that included soft tissue composition changes explained the most variation compared with those with body weight or EX and CA alone. Larger amounts of variation in BMD changes were explained in the no HT group. CONCLUSION Body composition changes are important positive predictors of BMD changes independent of EX and CA supplementation, but their contribution varies according to bone site and with HT use.
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Affiliation(s)
- L A Milliken
- Department of Exercise and Health Sciences, University of Massachusetts Boston, MA 02125, USA.
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Thompson JL, Davis SM, Gittelsohn J, Going S, Becenti A, Metcalfe L, Stone E, Harnack L, Ring K. Patterns of physical activity among American Indian children: an assessment of barriers and support. J Community Health 2001; 26:423-45. [PMID: 11759094 PMCID: PMC4890467 DOI: 10.1023/a:1012507323784] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Estimates indicate that 10% to 50% of American Indian and non-Indian children in the U.S. are obese, defined as a body mass index > or = 95th percentile of the NHANES II reference data. Pathways is a two-phase, multi-site study to develop and test a school-based obesity prevention program in American Indian schoolchildren in grades three through five. During Phase I feasibility prior to initiation of the Pathways trial, data were collected related to physical activity patterns, and the supports of, and barriers to, physical activity. Nine schools from communities representing six different tribal groups participated in this study. Multiple measures were used for data collection including direct observation, paired child interviews, and in-depth interviews and focus groups with adults. Students completed the self-administered Knowledge, Attitudes, and Behaviors (KAB) survey, and a Physical Activity Questionnaire (PAQ). Barriers to physical activity at schools included a lack of facilities, equipment, and trained staff persons for PE. Adults were not consistently active with their children, but they were highly supportive of their children's activity level. Children reported a strong enjoyment of physical activity and strong peer support to be physically active. Weather conditions, safety concerns, and homework/chores were common barriers to physical activity reported by children and adult caregivers. The information was used to design culturally and age-appropriate, practical interventions including the five physical activity programs for schoolchildren in the Pathways study.
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Affiliation(s)
- J L Thompson
- University of New Mexico Health Sciences Center, Center for Health Promotion and Disease Prevention, Albuquerque 87131-5311, USA.
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Habing HJ, Dominik C, Jourdain de Muizon M, Kessler MF, Laureijs RJ, Leech K, Metcalfe L, Salama A, Siebenmorgen R, Trams N. Disappearance of stellar debris disks around main-sequence stars after 400 million years. Nature 1999. [DOI: 10.1038/46749] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gittelsohn J, Evans M, Story M, Davis SM, Metcalfe L, Helitzer DL, Clay TE. Multisite formative assessment for the Pathways study to prevent obesity in American Indian schoolchildren. Am J Clin Nutr 1999; 69:767S-772S. [PMID: 10195601 PMCID: PMC4878016 DOI: 10.1093/ajcn/69.4.767s] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We describe the formative assessment process, using an approach based on social learning theory, for the development of a school-based obesity-prevention intervention into which cultural perspectives are integrated. The feasibility phase of the Pathways study was conducted in multiple settings in 6 American Indian nations. The Pathways formative assessment collected both qualitative and quantitative data. The qualitative data identified key social and environmental issues and enabled local people to express their own needs and views. The quantitative, structured data permitted comparison across sites. Both types of data were integrated by using a conceptual and procedural model. The formative assessment results were used to identify and rank the behavioral risk factors that were to become the focus of the Pathways intervention and to provide guidance on developing common intervention strategies that would be culturally appropriate and acceptable to all sites.
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Affiliation(s)
- J Gittelsohn
- The Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205, USA.
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Davis SM, Going SB, Helitzer DL, Teufel NI, Snyder P, Gittelsohn J, Metcalfe L, Arviso V, Evans M, Smyth M, Brice R, Altaha J. Pathways: a culturally appropriate obesity-prevention program for American Indian schoolchildren. Am J Clin Nutr 1999; 69:796S-802S. [PMID: 10195605 PMCID: PMC4868131 DOI: 10.1093/ajcn/69.4.796s] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pathways, a culturally appropriate obesity prevention study for third-, fourth-, and fifth-grade American Indian schoolchildren includes an intervention that promotes increased physical activity and healthful eating behaviors. The Pathways intervention, developed through a collaboration of universities and American Indian nations, schools, and families, focuses on individual, behavioral, and environmental factors and merges constructs from social learning theory with American Indian customs and practices. We describe the Pathways program developed during 3 y of feasibility testing in American Indian schools, with special emphasis on the activities developed for the third grade; review the theoretical and cultural underpinnings of the program; outline the construction process of the intervention; detail the curriculum and physical education components of the intervention; and summarize the formative assessment and the school food service and family components of the intervention.
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Affiliation(s)
- S M Davis
- University of New Mexico, School of Medicine, Center for Health Promotion and Disease Prevention, Albuquerque 87131-5311, USA.
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Gittelsohn J, Evans M, Helitzer D, Anliker J, Story M, Metcalfe L, Davis S, Iron Cloud P. Formative research in a school-based obesity prevention program for Native American school children (Pathways). Health Educ Res 1998; 13:251-65. [PMID: 10181023 PMCID: PMC4871612 DOI: 10.1093/her/13.2.251] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This paper describes how formative research was developed and implemented to produce obesity prevention interventions among school children in six different Native American nations that are part of the Pathways study. The formative assessment work presented here was unique in several ways: (1) it represents the first time formative research methods have been applied across multiple Native American tribes; (2) it is holistic, including data collection from parents, children, teachers, administrators and community leaders; and (3) it was developed by a multi-disciplinary group, including substantial input from Native American collaborators. The paper describes the process of developing the different units of the protocol, how data collection was implemented and how analyses were structured around the identification of risk behaviors. An emphasis is placed on describing which units of the formative assessment protocol were most effective and which were less effective.
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Affiliation(s)
- J Gittelsohn
- Center for Human Nutrition, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA
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Draper MH, Duffus JH, John P, Metcalfe L, Morgan L, Park MV, Weitzner MI. Characterization of historical samples of nickel refinery dusts from the Clydach refinery. Exp Toxicol Pathol 1994; 46:111-3. [PMID: 7987067 DOI: 10.1016/s0940-2993(11)80034-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- M H Draper
- Edinburgh Centre for Toxicology, Heriot-Watt University, Scotland
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Abstract
After characterization of bulk samples by inductively coupled plasma emission spectroscopic (ICP-ES) quantitative analysis and X-ray powder diffraction studies, single particle techniques using quantitative image analysis, scanning electron microscopy--energy dispersive analysis by X-ray, and finally laser beam ionization mass spectrometry analysis (LIMA) for surface analysis have been applied to historical nickel refinery dust samples from the nickel refining plant at Clydach in Wales. There were two historical samples of processed material from 1920 and 1929. These samples had a remarkably small particle size range, mean 3 microns and range, 0.75-24 microns. The most significant difference in elemental composition was the presence of 10% arsenic in the 1920 sample compared with 1% in the 1929 sample. The X-ray spectra revealed the presence of NiO in both. However, surprisingly, CuO was identified only in the 1929 sample. Of particular interest was the presence of a component, in the 1920 sample only, identified as the mineral orcelite, a copper-iron-nickel-arsenide-sulphide mineral, predominantly, Ni5-XAs2. Using the LIMA technique, it was found that in both samples, arsenic and arsenic derivative peaks are prominent, indicating the surface availability of arsenic compounds.
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Metcalfe L. Diabetes. Operations manager. Nurs Times 1993; 89:40-4. [PMID: 8437922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Metcalfe L, Chen SL, Mounts P. Structural analysis of human papillomavirus type 6c isolates from condyloma acuminatum and juvenile-onset and adult-onset laryngeal papillomata. Virus Genes 1989; 3:11-27. [PMID: 2554585 DOI: 10.1007/bf00301984] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The human papillomavirus type 6c (HPV-6c) genome was molecularly cloned from biopsy specimens of a juvenile-onset and an adult-onset respiratory-tract papillomata and a condyloma acuminatum of the cervix. To determine if the genital-tract isolate and respiratory-tract isolates contain divergent sequences that may account for a difference in tissue trophism or for a difference in the age of onset of the disease, fine-structure mapping, heteroduplex analysis by electron microscopy, and nucleotide sequencing were used to examine the sequence relationship among these HPV-6c isolates. No differences were found in the digestion patterns with 23 restriction enzymes. Heteroduplex analysis among the three genomes demonstrated that they were colinear without apparent deletions or rearrangements and had greater than 90% sequence identity. In heteroduplex analyses with a different subtype (HPV-6e) that was molecularly cloned from a genital wart, the genomes were colinear with greater than 90% sequence identity over 90% of their length. The most divergent region had 75-80% sequence identity and was localized to the part of the genome containing the E5a and E5b open reading frames (ORFs). Comparison of the sequence of 1430 nucleotides in this region for two of the HPV-6c isolates did not identify any differences between them. Comparison with the published sequences of HPV-6b identified deletions/insertions and base changes with approximately 75% sequence identity, and comparison with HPV-11 identified only six base changes. Conservation of sequences in the E4-E5 region and similarity in the restriction enzyme maps demonstrated that HPV-6c and HPV-11 are independent isolates of the same HPV-6 subtype.
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Affiliation(s)
- L Metcalfe
- Department of Immunology and Infectious Diseases, Johns Hopkins University, School of Public Health, Baltimore, MD
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Emanuele NV, Azad N, Luckey JP, Engel J, Melone G, Metcalfe L, Gout PW, Beer CT, Kirsteins L, Lawrence AM. Presence of prolactin-like immunoreactivity and bioactivity in rat spinal cord. Neuroendocrinology 1989; 49:331-5. [PMID: 2716957 DOI: 10.1159/000125135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pursuant to our identification of prolactin-like immunoreactivity (PLI), widely distributed in rat brain, the spinal cord was examined for the presence of this pituitary-hormone-like protein. PLI was present in all spinal cord extracts examined and averaged 500 +/- 53 pg/mg protein. Hypophysectomy, causing a fall in serum prolactin to undetectable levels, was not associated with any change in levels of PLI in spinal cord. Recovery of rat prolactin standards added to spinal cord homogenates was 97.6 +/- 3.9%. When increasing concentrations of spinal cord extract were assayed in a prolactin radioimmunoassay, displacement of rat 125I-Prolactin from antiserum was parallel to that displacement produced by increasing concentrations of rat anterior pituitary standards. Upon subjection to gel permeation chromatography, the elution profiles of immunoreactive prolactin from spinal cord were different from the profiles of anterior pituitary prolactin. In addition to an immunoreactive prolactin peak eluting with pituitary prolactin, spinal cord extracts showed a large void volume peak and late eluting low-molecular-weight materials not seen with anterior pituitary. In the Nb2 lymphoma cell assay, all spinal cord extracts demonstrated prolactin-like bioactivity with a bioactivity/immunoreactivity ratio of 1.05 +/- 0.13. We conclude: (1) PLI, widely distributed in rat brain, is also present in spinal cord; (2) spinal cord prolactin levels are independent of levels in pituitary and peripheral circulation; (3) this immunoreactive prolactin is bioactive, and (4) differing gel permeation chromatographic elution profiles indicate that there may be some molecular differences between pituitary and spinal cord prolactin.
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Affiliation(s)
- N V Emanuele
- Research Service, Veterans Administration Hospital, Hines, Ill
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Abstract
Exposure to ethanol is recognized to cause reproductive impairment in man and animals. Since elevated levels of prolactin will interfere with normal functioning of the hypothalamic-pituitary-gonadal axis, and since ethanol has been shown by others to lead to increased prolactin secretion in vivo, the present in vitro study was undertaken to determine whether there is a direct effect of ethanol (ETOH) on prolactin release. Prolactin release from anterior pituitary cells maintained in monolayer culture and exposed to either no ethanol or media containing ethanol at concentrations of 50, 100, 200, or 400 mg% was measured at 1, 4, 24, 48, 72 hours in incubation. Ethanol added directly to pituitary cells stimulated prolactin release at all time points examined. Significant stimulation occurred with addition of low and mid-range ethanol concentrations (50-200 mg%); no augmented prolactin secretory response was seen with the highest ethanol concentration used (400 mg%). This pattern of response was maintained throughout the entire 72 hour incubation period. Thus, the effect of ethanol on prolactin secretion is mediated, at least in part, at the anterior pituitary level.
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Affiliation(s)
- M A Emanuele
- Research Service, Veterans Adminstration Hospital, Hines, IL 60141
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Emanuele NV, Metcalfe L, Wallock L, Tentler J, Hagen TC, Beer CT, Martinson D, Gout PW, Kirsteins L, Lawrence AM. Extrahypothalamic brain prolactin: characterization and evidence for independence from pituitary prolactin. Brain Res 1987; 421:255-62. [PMID: 3690272 DOI: 10.1016/0006-8993(87)91295-9] [Citation(s) in RCA: 20] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Prompted by reports of immunohistochemical localization of a prolactin-like immunoreactivity (PLI) within the rat brain, a study was undertaken to define the immunologic and biologic characteristics of this material in extrahypothalamic regions of the rat brain. Ninety-seven percent recovery of rat prolactin standard, added to homogenates of brain parts, insured that neuronal tissue did not interfere with the radioimmunoassay for rat prolactin. PLI was consistently found in the cerebellum, thalamus, brainstem (pons-medulla), hippocampus, cerebral cortex and caudate. Examination of the elution profile of each of the extrahypothalamic brain parts from Sephadex G-75 columns showed that, although a small amount of brain PLI elutes in the vicinity of the anterior pituitary prolactin marker, the bulk of brain-based PLI migrates with the void volume and as late eluting, low molecular weight material. While increasing amounts of brain extracts progressively displaced more 125I-prolactin from antibody binding, the displacement curve was not parallel to that produced by the addition of increasing amounts of anterior pituitary prolactin standards of rat origin. Extracts of various brain parts from hypophysectomized animals, analyzed for biologic activity in the Nb2 lymphoma cell assay, revealed prolactin-like bioactivity, but the bioactivity/immunoreactivity ratio for some of the brain parts was significantly lower than that for pituitary prolactin. Hypophysectomy, which led to the expected fall in serum prolactin to undetectable levels, and restraint stress, which resulted in a statistically significant 4-fold rise in serum prolactin, caused no change in prolactin concentrations in extrahypothalamic brain parts, indicating that brain PLI is regulated independently of pituitary prolactin and of circulating serum prolactin levels.
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Affiliation(s)
- N V Emanuele
- Research Service, Veterans Administration Hospital, Hines, IL 60141
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Emanuele NV, Metcalfe L, Lubrano T, Rubinstein H, Kirsteins L, Lawrence AM. Subcellular distribution of hypothalamic prolactin-like immunoreactivity. Brain Res 1987; 407:223-9. [PMID: 3567642 DOI: 10.1016/0006-8993(87)91100-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Prompted by interest in immunohistochemical reports of prolactin-like immunoreactivity (PLI) in the rat hypothalamus, we investigated and have reported that an immunoreactive and bioactive prolactin-like material can be extracted from the rat hypothalamus. In the present communication the subcellular distribution of this protein is reported. Using a sensitive and specific radioimmunoassay for rat prolactin and a standardized procedure for subcellular fractionation of neuronal tissue, we have found that 90% of hypothalamic PLI is particulate-bound with only 10% remaining in the S4 or cytosolic fraction. Almost 80% of the particulate-bound PLI is found in the P2 fraction containing myelin, synaptosomes and mitochondria. When P2 is further fractioned on a discontinuous sucrose density gradient, approximately 66% of the P2-associated PLI was found in subfractions rich in synaptosomes and poor in myelin and mitochondria. Such findings support the probability that hypothalamic PLI functions trans-synaptically as a neuromodulator in the brain.
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Emanuele NV, Metcalfe L, Wallock L, Tentler J, Hagen TC, Beer CT, Martinson D, Gout PW, Kirsteins L, Lawrence AM. Hypothalamic prolactin: characterization by radioimmunoassay and bioassay and response to hypophysectomy and restraint stress. Neuroendocrinology 1986; 44:217-21. [PMID: 3796795 DOI: 10.1159/000124648] [Citation(s) in RCA: 33] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Prompted by immunohistochemical reports of prolactin-like immunoreactivity in cell bodies within the rat hypothalamus, a study was undertaken to quantitate the immunologic and biologic activity of this material. Hypothalamic concentrations of prolactin-like immunoreactivity averaged 402 +/- 23 pg/mg of protein (n = 30). 97% recovery of rat prolactin standards added to homogenates of hypothalamus insured that neuronal tissue, as prepared for these studies, did not interfere with the radioimmunoassay of rat prolactin. Examination of the elution profile from Sephadex G-75 columns of the prolactin-like immunoreactivity in hypothalamic extracts showed that the majority of hypothalamic prolactin-like substance was of a larger molecular size than pituitary prolactin. While increasing amounts of brain extract progressively displaced more I125 prolactin from antibody-binding sites, the displacement curve produced by adding hypothalamic extract was not parallel to that produced by the addition of increasing amounts of anterior pituitary prolactin standards of rat origin. Hypothalamic extracts from hypophysectomized animals, analyzed for biologic activity in the Nb2 lymphoma cell assay, revealed prolactin-like bioactivity, but the bioactivity/immunoactivity (B/I) ratios for hypothalamic extracts were significantly lower than the B/I ratios for pituitary prolactin (0.71 +/- 0.04 for pituitary, vs. 0.19 +/- 0.06 in the hypothalamus; p less than 0.001). Hypophysectomy, which led to the expected fall in serum prolactin to undetectable levels, and restraint stress, which resulted in a statistically significant 4-fold rise in serum prolactin, caused no change in prolactin concentrations in the hypothalamus, indicating that brain prolactin-like substance is regulated independently of pituitary prolactin and circulating serum prolactin levels.
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