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  1. Article: Purification and characterization of astrocyte-secreted apolipoprotein E and J-containing lipoproteins from wild-type and human apoE transgenic mice.

    DeMattos, R B / Brendza, R P / Heuser, J E / Kierson, M / Cirrito, J R / Fryer, J / Sullivan, P M / Fagan, A M / Han, X / Holtzman, D M

    Neurochemistry international

    2001  Volume 39, Issue 5-6, Page(s) 415–425

    Abstract: The varepsilon4 allele of apolipoprotein E (apoE) is a genetic risk factor for Alzheimer's disease (AD). In order to gain a better understanding of the molecular mechanisms by which apoE and possibly other apolipoproteins produced in the central nervous ... ...

    Abstract The varepsilon4 allele of apolipoprotein E (apoE) is a genetic risk factor for Alzheimer's disease (AD). In order to gain a better understanding of the molecular mechanisms by which apoE and possibly other apolipoproteins produced in the central nervous system (CNS) influence AD pathogenesis, we have purified and characterized the two most abundant apolipoproteins produced in the CNS, apoE and apoJ. We purified apoE and apoJ from primary cultures of mouse astrocytes, which were derived from transgenic mice expressing human apoE isoforms in the absence of mouse apoE. Utilizing antibody affinity columns, we were able to purify both human apoE3 and apoE4, as well as mouse apoJ-containing lipoproteins. Astrocyte-secreted human apoE was present in high density-like lipoproteins of three predominant sizes ranging from 8 to 15 nm in diameter. Mouse apoJ was in particles between 10 and 17 nm in diameter with a peak size range of approximately 11 nm. ApoE and apoJ were in distinct lipoproteins. Utilization of quick-freeze, deep-etch electron microscopy revealed the apoE particles were discs while the apoJ particles were smaller and more irregular in appearance. The lipid composition of apoE particles was very different from those containing apoJ. ApoE-particles contained a similar mass of apoE and lipid, with cholesterol and phospholipid being about equal in mass per particle. ApoJ-particles were relatively lipid poor (three parts protein, one part lipid), with phospholipids being much more abundant than cholesterol. Detailed characterization of phospholipid composition by electrospray ionization mass spectrometry analysis revealed ethanolamine glycerophospholipids to be the most abundant phospholipid present in both apoE and apoJ particles. Analysis of cerebrospinal fluid from apoE3 and apoE4 transgenic mice revealed that human and mouse apoE were in particles the same size as those secreted by astrocytes. Further use of physiological preparations of CNS-derived lipoproteins may allow for a detailed understanding of the role of these molecules in the normal brain and in diseases such as AD.
    MeSH term(s) Animals ; Apolipoproteins E/analysis ; Apolipoproteins E/cerebrospinal fluid ; Apolipoproteins E/chemistry ; Astrocytes/metabolism ; Cells, Cultured ; Clusterin ; Glycoproteins/analysis ; Glycoproteins/cerebrospinal fluid ; Glycoproteins/chemistry ; Humans ; Lipids/analysis ; Lipoproteins/chemistry ; Lipoproteins/isolation & purification ; Lipoproteins, HDL/chemistry ; Mice ; Mice, Transgenic ; Molecular Chaperones/analysis ; Molecular Chaperones/cerebrospinal fluid ; Molecular Chaperones/chemistry ; Particle Size ; Phospholipids/analysis ; Reference Values
    Chemical Substances Apolipoproteins E ; CLU protein, human ; Clu protein, mouse ; Clusterin ; Glycoproteins ; Lipids ; Lipoproteins ; Lipoproteins, HDL ; Molecular Chaperones ; Phospholipids
    Language English
    Publishing date 2001-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 283190-9
    ISSN 1872-9754 ; 0197-0186
    ISSN (online) 1872-9754
    ISSN 0197-0186
    DOI 10.1016/s0197-0186(01)00049-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Longitudinal Associations Among Low-Income Mothers' and Fathers' Parenting and Relationships with Children and Adolescent Depression.

    Fagan, Jay

    Research on child and adolescent psychopathology

    2022  Volume 50, Issue 10, Page(s) 1339–1350

    Abstract: Few studies have examined the associations among quality of parent-child relationships, parenting, and adolescent depression in samples of low-income mothers and fathers with large numbers of nonresidential fathers. This study used the Fragile Families ... ...

    Abstract Few studies have examined the associations among quality of parent-child relationships, parenting, and adolescent depression in samples of low-income mothers and fathers with large numbers of nonresidential fathers. This study used the Fragile Families and Child Wellbeing data (N = 3,384) to examine the longitudinal associations among parent-child closeness, harsh parenting, and neglect when children were nine years old and adolescent depression at age 15. The findings indicated that children who perceived having close relationships with mothers and fathers at age nine reported significantly less depression at age 15, regardless of residential status. Moderation analyses showed a stronger negative relationship between daughters' closeness with mothers and depression than sons' closeness with mothers and depression. Daughters and sons who were close to fathers reported less depression. There were no significant associations among harsh discipline or neglect and depression. The findings support the use of interventions that promote healthy attachments and close parent-child relationships between low-income parents and children.
    MeSH term(s) Female ; Humans ; Adolescent ; Child ; Male ; Parenting ; Depression/epidemiology ; Mothers ; Parent-Child Relations ; Fathers
    Language English
    Publishing date 2022-03-18
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3041907-4
    ISSN 2730-7174 ; 2730-7166
    ISSN (online) 2730-7174
    ISSN 2730-7166
    DOI 10.1007/s10802-022-00918-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Semon Lecture: 'Laryngectomy Practice Based on Personal Research', Royal Society of Medicine, 5 November 2020, London, UK.

    Fagan, J J

    The Journal of laryngology and otology

    2021  Volume 135, Issue 7, Page(s) E3

    Abstract: I wish to thank the Semon Committee for inviting me to deliver the 2020 Semon lecture. This is a very special honour, as is evidenced by the list of distinguished lecturers dating back to the inaugural lecture delivered at University College London in ... ...

    Abstract I wish to thank the Semon Committee for inviting me to deliver the 2020 Semon lecture. This is a very special honour, as is evidenced by the list of distinguished lecturers dating back to the inaugural lecture delivered at University College London in 1913. I am not the first South African to deliver the Semon lecture, having been preceded by my previous chairman Sean Sellars in 1993, and by Jack Gluckman in 2001, who was South African raised and educated and who subsequently became the chairman of otolaryngology in Cincinnati, USA.
    MeSH term(s) Biomedical Research ; Cutaneous Fistula/prevention & control ; Enteral Nutrition/methods ; Health Resources ; Humans ; Laryngeal Neoplasms/surgery ; Laryngectomy/methods ; Larynx, Artificial ; Neoplasm Recurrence, Local/epidemiology ; Organ Sparing Treatments ; Otolaryngology ; Pharyngeal Diseases/prevention & control ; Postoperative Care/methods ; Postoperative Complications/prevention & control ; Proton Pump Inhibitors/therapeutic use ; Quality of Life ; Radiotherapy ; Social Class ; South Africa ; Speech, Esophageal ; Surgical Stomas ; Thyroidectomy ; Tracheostomy/methods
    Chemical Substances Proton Pump Inhibitors
    Language English
    Publishing date 2021-06-17
    Publishing country England
    Document type Journal Article ; Lecture
    ZDB-ID 218299-3
    ISSN 1748-5460 ; 0022-2151
    ISSN (online) 1748-5460
    ISSN 0022-2151
    DOI 10.1017/S0022215121001511
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Editorial: Otolaryngology education and training in the COVID-19 and post-COVID-19 digital era: a developing world perspective.

    Fagan, Johannes J

    Current opinion in otolaryngology & head and neck surgery

    2021  Volume 29, Issue 3, Page(s) 219–220

    MeSH term(s) COVID-19/epidemiology ; Developing Countries ; Education, Distance/organization & administration ; Humans ; Otolaryngology/education
    Language English
    Publishing date 2021-04-23
    Publishing country United States
    Document type Editorial
    ZDB-ID 1232518-1
    ISSN 1531-6998 ; 1068-9508
    ISSN (online) 1531-6998
    ISSN 1068-9508
    DOI 10.1097/MOO.0000000000000715
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Africa: A window on challenges and opportunities for head and neck cancer.

    Fagan, Johannes J

    Laryngoscope investigative otolaryngology

    2021  Volume 6, Issue 3, Page(s) 414–419

    Abstract: Background: Head and neck cancer occurs predominantly in the Developing World, with significant challenges relating to a high burden of disease, late presentation, and poor access to curative and palliative care.: Aims: This article describes ... ...

    Abstract Background: Head and neck cancer occurs predominantly in the Developing World, with significant challenges relating to a high burden of disease, late presentation, and poor access to curative and palliative care.
    Aims: This article describes challenges relating to head and neck cancer care in Sub-Saharan Africa.
    Material & methods: Educational and training innovations that have been undertaken to improve access to cancer care are presented under the following headings: Open Access Educational Resources African Head and Neck Society (AfHNS); African head and neck surgery fellowship training; AfHNS Virtual Tumor Board; The AfHNS Clinical Practice Guidelines for Head & Neck Cancers in Developing Countries and Limited Resource Settings. Concerns are also raised about universally applicable cancer staging systems.
    Results: The challenges facing African patients apply to equally to many other parts of the developing world.
    Discussion: The challenges facing African patients apply to equally to many other parts of the developing world.
    Conclusions: For outcomes of head and neck cancers to be improved globally, a far greater investment needs to be made in education and training to improve access to care in developing countries. To make a meaningful global impact on morbidity and mortality related to HNC, clinicians, academic institutions and professional societies in developed countries need to be sensitive to these developing world challenges and should directly engage in improving access to care through promoting open access educational resources, offering specialist and fellowship training, collaborating with appropriate research, and establishing and strengthening centers of excellence in developing countries.
    Level of evidence: 2c "Outcomes research".
    Language English
    Publishing date 2021-03-30
    Publishing country United States
    Document type Journal Article
    ISSN 2378-8038
    ISSN 2378-8038
    DOI 10.1002/lio2.554
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The effect of frequency (64-498 MHz) on specific absorption rate adjacent to metallic orthopedic screws in MRI: A numerical simulation study.

    Jacobs, Paul / Fagan, Andrew J

    Medical physics

    2023  Volume 51, Issue 2, Page(s) 1074–1082

    Abstract: Background: The imaging of patients with implanted electrically-conductive devices via magnetic resonance imaging at ultra-high fields is hampered by uncertainties relating to the potential for inducing tissue heating adjacent to the implant due to ... ...

    Abstract Background: The imaging of patients with implanted electrically-conductive devices via magnetic resonance imaging at ultra-high fields is hampered by uncertainties relating to the potential for inducing tissue heating adjacent to the implant due to coupling of energy from the incident electromagnetic field into the implant. Existing data in the peer-reviewed literature of comparisons across field strengths of tissue heating and its surrogate, the specific absorption rate (SAR), is scarce and contradictory, leading to further doubts pertaining to the safety of imaging patients with such devices.
    Purpose: The radiofrequency-induced SAR adjacent to orthopedic screws of varying length and at frequencies of 64 to 498 MHz was investigated via full-wave electromagnetic simulations, to provide an accurate comparison of SAR across MRI field strengths.
    Methods: Dipole antennas were used for RF transmission to achieve a uniform electric field tangential to the screws located 120 mm above the antenna midpoints, embedded in a bone-mimicking material. The input power to the antennas was constrained to achieve the following targets without the screw present: (i) E = 100 V/m, (ii) B
    Results: The peak SAR, occurring at the resonant screw length, substantially increased as the frequency decreased when the input power to the dipole antenna was constrained to achieve constant electric field in background tissue at the screws' locations. A similar pattern was observed when constraining input power to achieve constant B
    Conclusions: The study design allowed for a direct comparison to be performed of SAR across frequencies and implant lengths without the confounding effect of variable incident electric field. Lower frequencies produced substantially larger SAR values for implants approaching the resonant length for the worst-case uniform incident electric field along the screws' length. The data may inform risk-benefit assessments for imaging patients with orthopedic implants at the new clinical field strength of 7 Tesla.
    MeSH term(s) Humans ; Computer Simulation ; Electromagnetic Fields ; Radio Waves ; Prostheses and Implants ; Magnetic Resonance Imaging ; Phantoms, Imaging
    Language English
    Publishing date 2023-12-20
    Publishing country United States
    Document type Journal Article
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1002/mp.16902
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Editorial: Developing world perspectives in otolaryngology: infectious complications in otolaryngology.

    Fagan, Johannes J

    Current opinion in otolaryngology & head and neck surgery

    2020  Volume 28, Issue 3, Page(s) 172–173

    MeSH term(s) Developing Countries/economics ; Humans ; Infections/diagnosis ; Infections/economics ; Infections/etiology ; Infections/therapy ; Otolaryngology/economics ; Otorhinolaryngologic Diseases/complications ; Otorhinolaryngologic Diseases/diagnosis ; Otorhinolaryngologic Diseases/economics ; Otorhinolaryngologic Diseases/therapy
    Language English
    Publishing date 2020-04-24
    Publishing country United States
    Document type Editorial ; Introductory Journal Article
    ZDB-ID 1232518-1
    ISSN 1531-6998 ; 1068-9508
    ISSN (online) 1531-6998
    ISSN 1068-9508
    DOI 10.1097/MOO.0000000000000625
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Broadening the scope of father-child attachment research to include the family context.

    Fagan, Jay

    Attachment & human development

    2019  Volume 22, Issue 1, Page(s) 139–142

    Abstract: The associations between caregiver sensitivity and child-parent attachment tend to be weaker among fathers than among mothers. In this commentary, I argue that researchers should pay more attention to child-parent attachment relationships in the context ... ...

    Abstract The associations between caregiver sensitivity and child-parent attachment tend to be weaker among fathers than among mothers. In this commentary, I argue that researchers should pay more attention to child-parent attachment relationships in the context of the family, including coparenting relationships, gatekeeping, and amount of time mothers and fathers provide care to their children.
    MeSH term(s) Child Development ; Family Relations ; Father-Child Relations ; Fathers/psychology ; Humans ; Infant ; Mothers ; Object Attachment ; Parenting
    Language English
    Publishing date 2019-03-06
    Publishing country England
    Document type Journal Article
    ZDB-ID 1497969-x
    ISSN 1469-2988 ; 1461-6734
    ISSN (online) 1469-2988
    ISSN 1461-6734
    DOI 10.1080/14616734.2019.1589071
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Editorial: Priority setting in otolaryngology in under resourced settings: practical and ethical dilemma.

    Fagan, Johannes J

    Current opinion in otolaryngology & head and neck surgery

    2019  Volume 27, Issue 3, Page(s) 191–192

    MeSH term(s) Developing Countries/economics ; Health Care Rationing/economics ; Health Priorities/economics ; Humans ; Otolaryngology/economics ; Otolaryngology/methods
    Language English
    Publishing date 2019-03-20
    Publishing country United States
    Document type Editorial
    ZDB-ID 1232518-1
    ISSN 1531-6998 ; 1068-9508
    ISSN (online) 1531-6998
    ISSN 1068-9508
    DOI 10.1097/MOO.0000000000000534
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Open Access Publishing of Textbooks and Guidelines for Otolaryngologists in Developing Countries.

    Fagan, Johannes J

    OTO open

    2019  Volume 3, Issue 3, Page(s) 2473974X19861567

    Abstract: Accessing educational and scientific material is key to improving otolaryngology care in developing countries. Yet current financial models of publishers restrict access to academic information. This article describes the author's experience with self- ... ...

    Abstract Accessing educational and scientific material is key to improving otolaryngology care in developing countries. Yet current financial models of publishers restrict access to academic information. This article describes the author's experience with self-publishing 2 open access textbooks,
    Language English
    Publishing date 2019-07-10
    Publishing country United States
    Document type Journal Article
    ISSN 2473-974X
    ISSN (online) 2473-974X
    DOI 10.1177/2473974X19861567
    Database MEDical Literature Analysis and Retrieval System OnLINE

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