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Ghazal LV, Johnston H, Dodd E, Ramachandra Y, Giallourakis N, Fulginiti K, Kamen C. A Needs Assessment Approach for Adolescent and Young Adult Sexual and Gender Diverse Cancer Survivors. Int J Environ Res Public Health 2024; 21:424. [PMID: 38673335 PMCID: PMC11050404 DOI: 10.3390/ijerph21040424] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 03/22/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024]
Abstract
Sexual and gender diverse (SGD) adolescent and young adult (AYA) cancer survivors are an increasing and vulnerable group with unique needs that often remain unmet in the healthcare system. This paper describes the conceptualization and development of a community-based organization dedicated to serving SGD AYAs, in addition to reporting on the results of a community-led needs assessment. A total of 56 SGD AYA community members completed the online survey. Most participants were between the ages of 26 to 33, identified as white, cisgender, bisexual women, and had hematologic malignancies. Identified unmet needs of SGD AYAs included the following: sexual health and family planning; gender affirmation; financial stability; and emotional support. Areas within the community organization were identified as gaps, areas of expansion, and assets. Results highlight the role of community and academic partnerships in improving cancer care delivery for SGD AYA cancer survivors.
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Affiliation(s)
- Lauren V. Ghazal
- School of Nursing, University of Rochester, Rochester, NY 14642, USA
- Wilmot Cancer Institute, Rochester, NY 14642, USA;
| | - Hailey Johnston
- Escape, Lansing, MI 48915, USA; (H.J.); (E.D.); (Y.R.)
- School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | | | | - Charles Kamen
- Wilmot Cancer Institute, Rochester, NY 14642, USA;
- Department of Surgery, Cancer Control, University of Rochester Medical Center, Rochester, NY 14642, USA
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Pereira TJ, Bouakkar J, Johnston H, Pakosh M, Drake JD, Edgell H. The effects of oral contraceptives on resting autonomic function and the autonomic response to physiological stressors: a systematic review. Clin Auton Res 2023; 33:859-892. [PMID: 37971640 DOI: 10.1007/s10286-023-00996-0] [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: 06/14/2023] [Accepted: 10/15/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE This systematic review aimed to summarize how oral contraceptives (OC) affect resting autonomic function and the autonomic response to a variety of physiological stressors. METHODS A search strategy was created to retrieve citations investigating physiological responses comparing OC users to non-users (NOC) in response to autonomic reflex activation. RESULTS A total of 6148 citations were identified across databases from inception to June 2, 2022, and 3870 citations were screened at the abstract level after deduplication. Then, 133 texts were assessed at full-text level, and only 40 studies met eligibility requirements. Included citations were grouped by the aspect of autonomic function assessed, including autonomic reflex (i.e., baroreflex, chemoreflex, mechanoreflex, metaboreflex, and venoarterial reflex), or indicators (i.e., heart rate variability, pulse wave velocity, and sympathetic electrodermal activity), and physiological stressors that may alter autonomic function (i.e., auditory, exercise, mental or orthostatic stress, altitude, cold pressor test, sweat test, and vasodilatory infusions). CONCLUSION OC influence the physiological responses to chemoreflex, mechanoreflex, and metaboreflex activation. In terms of autonomic indices and physiological stressors, there are more inconsistencies within the OC literature, which may be due to estrogen dosage within the OC formulation (i.e., heart rate variability) or the intensity of the stressor (exercise intensity/duration or orthostatic stress). Further research is required to elucidate the effects of OC on these aspects of autonomic function because of the relatively small amount of available research. Furthermore, researchers should more clearly define or stratify OC use by duration, dose, and/or hormone cycling to further elucidate the effects of OC.
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Affiliation(s)
- T J Pereira
- School of Kinesiology and Health Science, York University, 355 Bethune College, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
| | - J Bouakkar
- School of Kinesiology and Health Science, York University, 355 Bethune College, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
| | - H Johnston
- School of Kinesiology and Health Science, York University, 355 Bethune College, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
| | - M Pakosh
- Library & Information Services, University Health Network, Toronto, ON, Canada
| | - J D Drake
- School of Kinesiology and Health Science, York University, 355 Bethune College, 4700 Keele St, Toronto, ON, M3J 1P3, Canada
- Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - H Edgell
- School of Kinesiology and Health Science, York University, 355 Bethune College, 4700 Keele St, Toronto, ON, M3J 1P3, Canada.
- Library & Information Services, University Health Network, Toronto, ON, Canada.
- Muscle Health Research Centre, York University, Toronto, ON, Canada.
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Waters AR, Turner C, Easterly CW, Tovar I, Mulvaney M, Poquadeck M, Johnston H, Ghazal LV, Rains SA, Cloyes KG, Kirchhoff AC, Warner EL. Exploring Online Crowdfunding for Cancer-Related Costs Among LGBTQ+ (Lesbian, Gay, Bisexual, Transgender, Queer, Plus) Cancer Survivors: Integration of Community-Engaged and Technology-Based Methodologies. JMIR Cancer 2023; 9:e51605. [PMID: 37902829 PMCID: PMC10644187 DOI: 10.2196/51605] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/14/2023] [Accepted: 09/22/2023] [Indexed: 10/31/2023] Open
Abstract
BACKGROUND Cancer survivors frequently experience cancer-related financial burdens. The extent to which Lesbian, Gay, Bisexual, Transgender, Queer, Plus (LGBTQ+) populations experience cancer-related cost-coping behaviors such as crowdfunding is largely unknown, owing to a lack of sexual orientation and gender identity data collection and social stigma. Web-scraping has previously been used to evaluate inequities in online crowdfunding, but these methods alone do not adequately engage populations facing inequities. OBJECTIVE We describe the methodological process of integrating technology-based and community-engaged methods to explore the financial burden of cancer among LGBTQ+ individuals via online crowdfunding. METHODS To center the LGBTQ+ community, we followed community engagement guidelines by forming a study advisory board (SAB) of LGBTQ+ cancer survivors, caregivers, and professionals who were involved in every step of the research. SAB member engagement was tracked through quarterly SAB meeting attendance and an engagement survey. We then used web-scraping methods to extract a data set of online crowdfunding campaigns. The study team followed an integrated technology-based and community-engaged process to develop and refine term dictionaries for analyses. Term dictionaries were developed and refined in order to identify crowdfunding campaigns that were cancer- and LGBTQ+-related. RESULTS Advisory board engagement was high according to metrics of meeting attendance, meeting participation, and anonymous board feedback. In collaboration with the SAB, the term dictionaries were iteratively edited and refined. The LGBTQ+ term dictionary was developed by the study team, while the cancer term dictionary was refined from an existing dictionary. The advisory board and analytic team members manually coded against the term dictionary and performed quality checks until high confidence in correct classification was achieved using pairwise agreement. Through each phase of manual coding and quality checks, the advisory board identified more misclassified campaigns than the analytic team alone. When refining the LGBTQ+ term dictionary, the analytic team identified 11.8% misclassification while the SAB identified 20.7% misclassification. Once each term dictionary was finalized, the LGBTQ+ term dictionary resulted in a 95% pairwise agreement, while the cancer term dictionary resulted in an 89.2% pairwise agreement. CONCLUSIONS The classification tools developed by integrating community-engaged and technology-based methods were more accurate because of the equity-based approach of centering LGBTQ+ voices and their lived experiences. This exemplar suggests integrating community-engaged and technology-based methods to study inequities is highly feasible and has applications beyond LGBTQ+ financial burden research.
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Affiliation(s)
- Austin R Waters
- Department of Health Policy and Management, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States
- Cancer Control and Population Sciences, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
| | - Cindy Turner
- Cancer Control and Population Sciences, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- College of Nursing, University of Utah, Salt Lake City, UT, United States
| | - Caleb W Easterly
- Department of Health Policy and Management, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States
| | - Ida Tovar
- Cancer Control and Population Sciences, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- College of Nursing, University of Utah, Salt Lake City, UT, United States
| | - Megan Mulvaney
- Crowdfunding Cancer Costs LGBT Study Advisory Board, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- School of Public Health, Indiana University Bloomington, Bloomington, IN, United States
| | - Matt Poquadeck
- Crowdfunding Cancer Costs LGBT Study Advisory Board, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, United States
| | - Hailey Johnston
- Crowdfunding Cancer Costs LGBT Study Advisory Board, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
| | - Lauren V Ghazal
- Crowdfunding Cancer Costs LGBT Study Advisory Board, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- School of Nursing, University of Rochester, Rochester, NY, United States
| | - Stephen A Rains
- Department of Communication, University of Arizona, Tucson, AZ, United States
| | - Kristin G Cloyes
- School of Nursing, Oregon Health & Science University, Portland, OR, United States
| | - Anne C Kirchhoff
- Cancer Control and Population Sciences, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Echo L Warner
- Cancer Control and Population Sciences, Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT, United States
- College of Nursing, University of Utah, Salt Lake City, UT, United States
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Welford A, McCallum GB, Hodson M, Johnston H. Physiotherapy management of first nations children with bronchiectasis from remote top end communities of the northern territory: a retrospective chart audit. Front Pediatr 2023; 11:1230474. [PMID: 37900672 PMCID: PMC10613054 DOI: 10.3389/fped.2023.1230474] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/15/2023] [Indexed: 10/31/2023] Open
Abstract
Background Bronchiectasis is a chronic pulmonary disorder which is prevalent among Australian First Nations people in the Northern Territory (NT). Current guidelines recommend physiotherapy as part of multi-disciplinary management of children with bronchiectasis, however in our setting, involvement of physiotherapy remains unknown. We thus undertook a retrospective chart audit to examine physiotherapy management of First Nations children (<18 years) from remote First Nations communities in the Top End of the NT at the index bronchiectasis diagnosis and 12 months following diagnosis. Methods Participants were identified from a larger prospective study of children investigated for bronchiectasis at Royal Darwin Hospital, NT (2007-2016). Children were included if they were First Nations, aged <18 years, had a radiological diagnosis of bronchiectasis on high resolution computed tomography scan and lived in a remote community serviced by NT Government health clinics. The medical records from NT Government hospitals, health clinics and where possible other medical service attendance were reviewed for physiotherapy referral and management at the time of bronchiectasis diagnosis and in the following 12 months in the community. Results Of 143 children included, the mean age was 3.1 (standard deviation 2.4) years and 84 (58.7%) were males. At the index diagnosis, 76/122 (62.3%) children were reviewed by a physiotherapist, consisting of airway clearance techniques (83.8%), physical activity/exercise (81.7%) and caregiver education (83.3%), with only 7/127 (5.5%) having evidence of referral for community-based physiotherapy. In the following 12 months, only 11/143 (7.7%) children were reviewed by a physiotherapist, consisting of airway clearance techniques (54.5%), physical activity/exercise (45.5%) and caregiver education (36.4%). Conclusion This study demonstrates a significant gap in the provision of physiotherapy services in our setting and the need to develop a standardized pathway, to support the best practice management of children with bronchiectasis in remote Top End communities of the NT.
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Affiliation(s)
- A Welford
- Community Allied Health Team, Top End Population and Primary Healthcare, NT Health, Darwin, NT, Australia
| | - GB McCallum
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - M Hodson
- Community Allied Health Team, Top End Population and Primary Healthcare, NT Health, Darwin, NT, Australia
| | - H Johnston
- Community Allied Health Team, Top End Population and Primary Healthcare, NT Health, Darwin, NT, Australia
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Nair N, Johnston H, Du D. Machine Learning Ensemble Models for Predicting Post- Transplant Lymphoproliferative Disorder in Heart Transplant Recipients. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.041] [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: 04/05/2023] Open
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Nair N, Johnston H, Du D. A Logistic Regression Model for Post Transplant Lymphoproliferative Disorder Using the UNOS Database. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.798] [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: 10/18/2022] Open
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Johnston H, Pilkington P. The role for public health in building local partnerships to improve air quality and reduce health inequalities. Perspect Public Health 2021; 141:311-313. [PMID: 34816774 DOI: 10.1177/17579139211057151] [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: 11/15/2022]
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Scott E, Chan M, Johnston H, Lanier C, LeCompte M, Cramer C, Ruiz J, Lo H, Watabe K, O'Neill S, Whitlow C, Laxton A, Su J. Upfront Immunotherapy at the Time of Metastatic Cancer Diagnosis Leads to Lower Brain Metastasis Velocity in Patient Undergoing Stereotactic Radiosurgery for Brain Metastases. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.1557] [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: 10/20/2022]
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Fleming J, Eastment J, Johnston H, Tunster H, Riglin J, Hill M, Jalal H, Scheibl F, Mavrodaris A. 18WHAT IS NEEDED TO IMPLEMENT AND EVALUATE FALLS PREVENTION MOST EFFECTIVELY? Age Ageing 2017. [DOI: 10.1093/ageing/afx115.18] [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: 11/14/2022] Open
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Kakakhel MB, Jirasek A, Johnston H, Kairn T, Trapp JV. Improving the quality of reconstructed X-ray CT images of polymer gel dosimeters: zero-scan coupled with adaptive mean filtering. Australas Phys Eng Sci Med 2017; 40:159-165. [PMID: 28168587 DOI: 10.1007/s13246-017-0523-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 12/11/2015] [Accepted: 01/12/2017] [Indexed: 11/25/2022]
Abstract
This study evaluated the feasibility of combining the 'zero-scan' (ZS) X-ray computed tomography (CT) based polymer gel dosimeter (PGD) readout with adaptive mean (AM) filtering for improving the signal to noise ratio (SNR), and to compare these results with available average scan (AS) X-ray CT readout techniques. NIPAM PGD were manufactured, irradiated with 6 MV photons, CT imaged and processed in Matlab. AM filter for two iterations, with 3 × 3 and 5 × 5 pixels (kernel size), was used in two scenarios (a) the CT images were subjected to AM filtering (pre-processing) and these were further employed to generate AS and ZS gel images, and (b) the AS and ZS images were first reconstructed from the CT images and then AM filtering was carried out (post-processing). SNR was computed in an ROI of 30 × 30 for different pre and post processing cases. Results showed that the ZS technique combined with AM filtering resulted in improved SNR. Using the previously-recommended 25 images for reconstruction the ZS pre-processed protocol can give an increase of 44% and 80% in SNR for 3 × 3 and 5 × 5 kernel sizes respectively. However, post processing using both techniques and filter sizes introduced blur and a reduction in the spatial resolution. Based on this work, it is possible to recommend that the ZS method may be combined with pre-processed AM filtering using appropriate kernel size, to produce a large increase in the SNR of the reconstructed PGD images.
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Affiliation(s)
- M B Kakakhel
- Department of Physics and Applied Mathematics (DPAM), Pakistan Institute of Engineering and Applied Sciences, Nilore, 45450, Islamabad, Pakistan
| | - A Jirasek
- I.K. Barber School of Arts and Science, University of British Columbia, Okanagan Campus, Vancouver, BC, Canada
| | - H Johnston
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - T Kairn
- Genesis Cancer Care Queensland, Brisbane, QLD, Australia.
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia.
| | - J V Trapp
- Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
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Dalhart A, Hyer D, Allen B, Flynn R, Johnston H. SU-F-T-646: SBRT Lung: Moving Beyond the 3D Conformal Paradigm with An Elekta VersaHD Accelerator. Med Phys 2016. [DOI: 10.1118/1.4956831] [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: 11/07/2022] Open
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Johnston H, Jacobson T, Gu X, Jiang S, Stojadinovic S. SU-E-T-184: Clinical VMAT QA Practice Using LINAC Delivery Log Files. Med Phys 2015. [DOI: 10.1118/1.4924545] [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: 11/07/2022] Open
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Abstract
In this work we investigate radiation dose rate dependencies of N-isopropylacrylamide (NIPAM) based polymer gel dosimeters (PGDs) used in conjunction with x-ray computed tomography imaging for radiotherapy dose verification. We define four primary forms of dose rate variation: constant mean dose rate where beam on and beam off times both vary, variable mean dose rate where beam on time varies, variable mean dose rate where beam off time varies and machine dose rate (MU min(-1)). We utilize both small (20 mL) vials and large volume (1L) gel containers to identify and characterize dose rate dependence in NIPAM PGDs. Results indicate that all investigated constant and variable mean dose rates had negligible affect on PGD dose response with the exception of machine dose rates (100-600 MU min(-1)) which produced variations in dose response significantly lower than previously reported. Explanations of the reduced variability in dose response are given. It is also shown that NIPAM PGD dose response is not affected by variations in dose rate that may occur in modulated treatment deliveries. Finally, compositional changes in NIPAM PGDs are investigated as potential mitigating strategies for dose rate-dependent response variability.
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Affiliation(s)
- A Jirasek
- Physics, Unit 5, IK Barber School of Arts and Science, University of British Columbia-Okanagan Campus, Kelowna BC V1V 1V7, Canada
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Abstract
PURPOSE To evaluate multislice computed tomography (CT) scanning for fast and reliable readout of radiation therapy (RT) dose distributions using CT polymer gel dosimetry (PGD) and to establish a baseline assessment of image noise and uniformity in an unirradiated gel dosimeter. METHODS A 16-slice CT scanner was used to acquire images through a 1 L cylinder filled with water. Additional images were collected using a single slice machine. The variability in CT number (NCT) associated with the anode heel effect was evaluated and used to define a new slice-by-slice background subtraction artifact removal technique for CT PGD. Image quality was assessed for the multislice system by evaluating image noise and uniformity. The agreement in NCT for slices acquired simultaneously using the multislice detector array was also examined. Further study was performed to assess the effects of increasing x-ray tube load on the constancy of measured NCT and overall scan time. In all cases, results were compared to the single slice machine. Finally, images were collected throughout the volume of an unirradiated gel dosimeter to quantify image noise and uniformity before radiation is delivered. RESULTS Slice-by-slice background subtraction effectively removes the variability in NCT observed across images acquired simultaneously using the multislice scanner and is the recommended background subtraction method when using a multislice CT system. Image noise was higher for the multislice system compared to the single slice scanner, but overall image quality was comparable between the two systems. Further study showed NCT was consistent across image slices acquired simultaneously using the multislice detector array for each detector configuration of the slice thicknesses examined. In addition, the multislice system was found to eliminate variations in NCT due to increasing x-ray tube load and reduce scanning time by a factor of 4 when compared to imaging a large volume using a single slice scanner. Images acquired through an unirradiated, active gel revealed NCT varies between the top and bottom of the 1 L cylinder as well as across the diameter of the cylinder by up to 7 HU. CONCLUSIONS Multislice CT imaging has been evaluated for CT PGD and found to be the superior technique compared to single slice imaging in terms of the time required to complete a scan and the tube load characteristics associated with each scanning method. The implementation of multislice scanning is straightforward and expected to facilitate routine gel dosimetry measurements for complex dose distributions in modern RT centers.
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Affiliation(s)
- H Johnston
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - M Hilts
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada and Medical Physics, BC Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5, Canada
| | - A Jirasek
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada and Department of Physics, University of British Columbia-Okanagan Campus, Kelowna, British Columbia V1V 1V7, Canada
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Kermanizadeh A, Gaiser BK, Johnston H, Brown DM, Stone V. Toxicological effect of engineered nanomaterials on the liver. Br J Pharmacol 2014; 171:3980-7. [PMID: 24111818 DOI: 10.1111/bph.12421] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [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: 04/22/2013] [Revised: 07/17/2013] [Accepted: 07/29/2013] [Indexed: 01/12/2023] Open
Abstract
The liver has a crucial role in metabolic homeostasis, as it is responsible for the storage, synthesis, metabolism and redistribution of carbohydrates, fats and vitamins, and numerous essential proteins. It is also the principal detoxification centre of the body, removing xenobiotics and waste products by metabolism or biliary excretion. An increasing number of studies have shown that some nanomaterials (NMs) are capable of distributing from the site of exposure (e.g. lungs, gut) to a number of secondary organs, including the liver. As a secondary exposure site the liver has been shown to preferentially accumulate NMs (>90% of translocated NMs compared with other organs), and alongside the kidneys may be responsible for the clearance of NMs from the blood. Research into the toxicity posed by NMs to the liver is expanding due to the realization that NMs accumulate in this organ following exposure via a variety of routes (e.g. ingestion, injection and inhalation). Thus it is critical to consider what advances have been made in the investigation of NM hepatotoxicity, as well as appraising the quality of the information available and gaps in the knowledge that still exist. The overall aim of this review is to outline what data are available in the literature for the toxicity elicited by NMs to the liver in order to establish a weight of evidence approach (for risk assessors) to inform on the potential hazards posed by NMs to the liver.
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Affiliation(s)
- A Kermanizadeh
- Nanosafety Research Group, School of Life Sciences, Heriot Watt University, Edinburgh, UK
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Alam A, Bracken H, Winikoff B, Johnston H, Reichenbach L. O034 MENSTRUAL REGULATION USING MEDICATION IS ACCEPTABLE AND FEASIBLE IN BANGLADESH. Int J Gynaecol Obstet 2012. [DOI: 10.1016/s0020-7292(12)60464-0] [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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Johnston H, Hilts M, Carrick J, Jirasek A. An x-ray CT polymer gel dosimetry prototype: II. Gel characterization and clinical application. Phys Med Biol 2012; 57:3155-75. [DOI: 10.1088/0031-9155/57/10/3155] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Foti D, Herdson C, Thompson S, Johnston H, McBroom K, Bride W. 25. Sodium awareness leadership team (SALT): Challenging home diet compliance of patients with heart failure. Heart Lung 2011. [DOI: 10.1016/j.hrtlng.2011.04.041] [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: 11/25/2022]
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Abstract
4-Amino-3,5,6-trichloropicolinic acid is more toxic to many broad-leaved plants than 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid. It is comparable in absorption by foliage, in translocation, and in soil-leaching characteristics; in soil, however, it retains its activity for a longer time.
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Johnston H, Hilts M, Beckham W, Berthelet E. 3D ultrasound for prostate localization in radiation therapy: A comparison with implanted fiducial markers. Med Phys 2008; 35:2403-13. [DOI: 10.1118/1.2924208] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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O'Shaughnessy PJ, Abel M, Charlton HM, Hu B, Johnston H, Baker PJ. Altered expression of genes involved in regulation of vitamin A metabolism, solute transportation, and cytoskeletal function in the androgen-insensitive tfm mouse testis. Endocrinology 2007; 148:2914-24. [PMID: 17332066 DOI: 10.1210/en.2006-1412] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [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] [Indexed: 11/19/2022]
Abstract
Androgens are essential for the development and maintenance of spermatogenesis, but the underlying mechanisms of androgen action in the testis remain unclear. To help clarify these mechanisms, gene expression was measured in testes of pubertal (20 d old), androgen-insensitive, testicular feminized (Tfm) mice and in normal controls. Using microarrays (Affymetrix chips 430A and 430B), initial data identified a large number of genes down-regulated in the Tfm testis (>4700). These genes were largely of germ cell origin, reflecting the arrest of spermatogenesis that is apparent in the 20-d-old Tfm testis. Subsequent screening in vitro and in silico of this gene set identified 20 genes of a somatic tubular origin that were significantly down-regulated in the Tfm testis and six genes that were significantly up-regulated. Altered expression of these genes was confirmed by real-time PCR, and genes down-regulated in the Tfm testis were shown to be up-regulated in testes of hypogonadal (hpg) mice treated with androgen. In a developmental study using real-time PCR most of the regulated genes showed normal expression during fetal and neonatal development and deviated from control only between 10 and 20 d. In all cases, expression was also reduced in the adult, although interpretation is more complex because of the inherent cryptorchidism in the adult Tfm mouse. Of the total number of somatic genes showing differential expression in the Tfm testis, 50% were associated with three separate groups of genes involved in regulation of vitamin A metabolism, solute transportation, and cytoskeletal function. Thus, effects of androgens on tubular function and spermatogenesis may be mediated in part through regulation of the tubular environment and control of retinoic acid concentrations.
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Affiliation(s)
- P J O'Shaughnessy
- Division of Cell Sciences, University of Glasgow Veterinary School, Bearsden Road, Glasgow, Scotland, United Kingdom.
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Abstract
During development in the mouse, two populations of Leydig cells arise sequentially. The fetal Leydig cell population arises shortly after testicular differentiation and functions primarily to produce androgens that are essential for masculinization of the fetus. The origin of the fetal Leydig stem cells remains uncertain, but it has been suggested that adrenocortical cells and fetal Leydig cells may share a common origin in an adrenogenital primordium. The fetal Leydig cells require an intact pituitary for normal development and are sensitive to both luteinizing hormone (LH) and adrenocorticotrophic hormone (ACTH). Loss of either one of these hormones does not, however, affect fetal androgen production, suggesting that both LH and ACTH may act to maintain fetal Leydig cell function in vivo in a redundant fashion. The adult Leydig cell population starts to develop soon after birth in the mouse. Initial differentiation does not appear to require gonadotropin input, but subsequent development and function are completely dependent upon LH. The adult Leydig cells do not require circulating follicle-stimulating hormone, provided that LH is present, but androgen stimulation, through the androgen receptor, is required for normal Leydig cell development in the mouse. It is likely that the effects of androgen are mediated directly in the Leydig cells or indirectly through the peritubular cells.
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Affiliation(s)
- P J O'Shaughnessy
- Division of Cell Sciences, Institute of Comparative Medicine, University of Glasgow Veterinary School, Bearsden Rd., Glasgow G61 1QH Scotland, UK.
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Abstract
The foetal Leydig cell population arises shortly after testicular differentiation at around 12.5 dpc in the mouse and 6 weeks in the human. These cells function, primarily, to produce androgens which are essential for masculinization of the foetus. The origin of the foetal Leydig cells remains uncertain but it has been suggested that adrenocortical cells and foetal Leydig cells may share a common origin in an adreno-genital primordium. Studies in the mouse are beginning to identify factors such as desert hedgehog and platelet-derived growth factor which are required for foetal Leydig cell development. Regulation of foetal Leydig cell function remains uncertain in most species. Unlike the adult population of Leydig cells, the foetal Leydig cells in the mouse do not require luteinizing hormone (LH) to stimulate androgen production. An intact pituitary does appear to be required, however, and adrenocorticotrophic hormone (ACTH) will stimulate foetal Leydig cell function directly suggesting that both LH and ACTH act to maintain Leydig cell function in vivo. In the human LH/hCG is required for foetal Leydig cell function although the cells may also be sensitive to ACTH.
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Affiliation(s)
- P J O'Shaughnessy
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Bearsden Rd, Glasgow G61 1QH, UK. P.O'
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O'Shaughnessy PJ, Fleming L, Baker PJ, Jackson G, Johnston H. Identification of developmentally regulated genes in the somatic cells of the mouse testis using serial analysis of gene expression. Biol Reprod 2003; 69:797-808. [PMID: 12748123 DOI: 10.1095/biolreprod.103.016899] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [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: 01/24/2023] Open
Abstract
To identify genes developmentally regulated in the somatic cells of the testis, serial analysis of gene expression (SAGE) has been used to generate gene expression profiles from these cells in the fetal and adult mouse. To avoid germ cell transcripts, a fetal SAGE library was generated from germ cell-free fetal Wv/Wv mice, and an adult SAGE library was generated from adult testes depleted of germ cells with busulfan. The combined SAGE libraries contained 147570 tags identifying 12976 unique transcripts. Of these transcripts, 3607 were present in only the fetal library and 3941 were present in only the adult library. Most of the abundant differentially expressed tags in the adult testis library were from characterized genes, whereas 3' rapid amplification of complementary ends was required to identify most differentially expressed tags in the fetal library. These fetal tags were mostly associated with uncharacterized UniGene clusters. These data provide a comprehensive and quantitative analysis of gene expression in the somatic cells of the fetal and adult testis (including unknown transcripts) and identify genes differentially expressed in these cells during testis development. These differentially regulated genes are likely to provide insight into mechanisms regulating testis function both during development and in the adult animal.
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Affiliation(s)
- P J O'Shaughnessy
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow, United Kingdom
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Baker PJ, Johnston H, Abel M, Charlton HM, O'Shaughnessy PJ. Differentiation of adult-type Leydig cells occurs in gonadotrophin-deficient mice. Reprod Biol Endocrinol 2003; 1:4. [PMID: 12646077 PMCID: PMC151561 DOI: 10.1186/1477-7827-1-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2003] [Accepted: 02/05/2003] [Indexed: 11/14/2022] Open
Abstract
During mammalian testis development distinct generations of fetal and adult Leydig cells arise. Luteinising hormone (LH) is required for normal adult Leydig cell function and for the establishment of normal adult Leydig cell number but its role in the process of adult Leydig cell differentiation has remained uncertain. In this study we have examined adult Leydig cell differentiation in gonadotrophin-releasing hormone (GnRH)-null mice which are deficient in circulating gonadotrophins. Adult Leydig cell differentiation was assessed by measuring expression of mRNA species encoding four specific markers of adult Leydig cell differentiation in the mouse. Each of these markers (3beta-hydroxysteroid dehydrogenase type VI (3betaHSD VI), 17beta-hydroxysteroid dehydrogenase type III (17betaHSD III), prostaglandin D (PGD)-synthetase and oestrogen sulphotransferase (EST)) is expressed only in the adult Leydig cell lineage in the normal adult animal. Real-time PCR studies showed that all four markers are expressed in adult GnRH-null mice. Localisation of 3betaHSD VI and PGD-synthetase expression by in situ hybridisation confirmed that these genes are expressed in the interstitial tissue of the GnRH-null mouse. Treatment of animals with human chorionic gonadotrophin increased expression of 3betaHSD VI and 17betaHSD III within 12 hours further indicating that differentiated, but unstimulated cells already exist in the GnRH-null mouse. Thus, while previous studies have shown that LH is required for adult Leydig cell proliferation and activity, results from the present study show that adult Leydig cell differentiation will take place in animals deficient in LH.
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Affiliation(s)
- PJ Baker
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Bearsden Rd, Glasgow G61 1QH, UK
| | - H Johnston
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Bearsden Rd, Glasgow G61 1QH, UK
| | - M Abel
- Department of Human Anatomy, University of Oxford South Parks Rd, Oxford OX1 3QX, UK
| | - HM Charlton
- Department of Human Anatomy, University of Oxford South Parks Rd, Oxford OX1 3QX, UK
| | - PJ O'Shaughnessy
- Institute of Comparative Medicine, University of Glasgow Veterinary School, Bearsden Rd, Glasgow G61 1QH, UK
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Jones KJ, Morgan G, Johnston H, Tobias V, Ouvrier RA, Wilkinson I, North KN. The expanding phenotype of laminin alpha2 chain (merosin) abnormalities: case series and review. J Med Genet 2001; 38:649-57. [PMID: 11584042 PMCID: PMC1734735 DOI: 10.1136/jmg.38.10.649] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [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: 11/04/2022]
Abstract
Initial reports of patients with laminin alpha2 chain (merosin) deficiency had a relatively homogeneous phenotype, with classical congenital muscular dystrophy (CMD) characterised by severe muscle weakness, inability to achieve independent ambulation, markedly raised creatine kinase, and characteristic white matter hypodensity on cerebral magnetic resonance imaging. We report a series of five patients with laminin alpha2 deficiency, only one of whom has this severe classical CMD phenotype, and review published reports to characterise the expanded phenotype of laminin alpha2 deficiency, as illustrated by this case series. While classical congenital muscular dystrophy with white matter abnormality is the commonest phenotype associated with laminin alpha2 deficiency, 12% of reported cases have later onset, slowly progressive weakness more accurately designated limb-girdle muscular dystrophy. In addition, the following clinical features are reported with increased frequency: mental retardation (~6%), seizures (~8%), subclinical cardiac involvement (3-35%), and neuronal migration defects (4%). At least 25% of patients achieve independent ambulation. Notably, three patients with laminin alpha2 deficiency were asymptomatic, 10 patients had normal MRI (four with LAMA2 mutations reported), and between 10-20% of cases had maximum recorded creatine kinase of less than 1000 U/l. LAMA2 mutations have been identified in 25% of cases. Sixty eight percent of these have the classical congenital muscular dystrophy, but this figure is likely to be affected by ascertainment bias. We conclude that all dystrophic muscle biopsies, regardless of clinical phenotype, should be studied with antibodies to laminin alpha2. In addition, the use of multiple antibodies to different regions of laminin alpha2 may increase the diagnostic yield and provide some correlation with severity of clinical phenotype.
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Affiliation(s)
- K J Jones
- Institute for Neuromuscular Research, The Children's Hospital at Westmead, Parramatta, Sydney, NSW 2124, Australia
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McConville C, Kalin RM, Johnston H, McNeill GW. Evaluation of recharge in a small temperate catchment using natural and applied delta 18O profiles in the unsaturated zone. Ground Water 2001; 39:616-23. [PMID: 11447861 DOI: 10.1111/j.1745-6584.2001.tb02349.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
A water balance study was used for determining recharge rate and mechanisms in the Enler Catchment, Northern Ireland. Here spatially limited data for the water balance resulted in varied calculation of the annual and monthly net infiltration rate. This paper outlines a method whereby high-resolution soil profiles (1 to 2 cm) were obtained from field cores in the upper 2 m of the unsaturated zone using delta 18O of water. These profiles show changes in isotopic composition that range from individual rainfall events to annually integrated cycles of rainfall. Recharge rates were calculated from stable isotope profiles for each of the four main soil types in the study catchment and summed over each area resulting in an average recharge in the range 55 to 70 mm/a, which is comparable with previous findings. Applied isotopic tracer tests were also conducted to evaluate the extent of preferential flow through the two main soil types in the catchment. Rates of water movement found from these experiments show good agreement with natural isotopic profiles; however, evidence suggests that preferential flow is not the dominant process controlling water movement in this catchment. This type of data provides valuable information about recharge rates and mechanisms and may facilitate better prediction of contaminant transport pathways in the vadose zone.
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Affiliation(s)
- C McConville
- Environmental Engineering Research Centre, School of Civil Engineering, Queen's University of Belfast, Belfast, Northern Ireland, BT7 1NN.
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Martin RE, Letsos P, Taves DH, Inculet RI, Johnston H, Preiksaitis HG. Oropharyngeal dysphagia in esophageal cancer before and after transhiatal esophagectomy. Dysphagia 2001; 16:23-31. [PMID: 11213243 DOI: 10.1007/s004550000044] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [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: 10/26/2022]
Abstract
Although dysphagia is the predominant symptom of esophageal cancer, the nature of the swallowing deficit remains unclear, particularly regarding an oropharyngeal motor component. The present study examined the oropharyngeal swallow in patients with esophageal cancer before and following transhiatal esophagectomy. Videofluoroscopic data were obtained from ten patients with esophageal cancer before and following transhiatal esophagectomy as they swallowed 2-, 5-, and 10-cc aliquots of liquid and puree, and 0.5 and 1 tsp of solid. Each swallow was rated on 36 parameters by three independent judges. Swallow-related hyoid bone movement, computed from digitized segments of the videofluoroscopic data, was compared pre- and postsurgically. All patients showed at least mild abnormality of the oropharyngeal swallow preoperatively. Abnormalities involved all stages of swallowing in nine of the ten patients; however, the oral preparatory/oral stage was relatively more impaired than the pharyngeal stage in the majority of patients. Postsurgically, all patients exhibited at least a mild oropharyngeal swallowing impairment. New or increased postoperative deficits involved the pharyngeal stage of swallowing, whereas oral stage abnormalities were generally improved or unchanged following surgery. Swallow-related hyoid kinematics were highly variable both before and following surgery. Anterior hyoid bone excursion was significantly reduced postoperatively in one patient and significantly increased in one patient. Patients with esophageal cancer exhibit oropharyngeal dysphagia, with different profiles of abnormality before and following esophagectomy.
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Affiliation(s)
- R E Martin
- Faculty of Health Sciences, University of Western Ontario, London, Ontario, Canada.
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Li H, Li SH, Johnston H, Shelbourne PF, Li XJ. Amino-terminal fragments of mutant huntingtin show selective accumulation in striatal neurons and synaptic toxicity. Nat Genet 2000; 25:385-9. [PMID: 10932179 DOI: 10.1038/78054] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.7] [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: 11/08/2022]
Abstract
Huntington disease (HD) is caused by expansion of a glutamine repeat in the amino-terminal region of huntingtin. Despite its widespread expression, mutant huntingtin induces selective neuronal loss in striatal neurons. Here we report that, in mutant mice expressing HD repeats, the production and aggregation of N-terminal huntingtin fragments preferentially occur in HD-affected neurons and their processes and axonal terminals. N-terminal fragments of mutant huntingtin form aggregates and induce neuritic degeneration in cultured striatal neurons. N-terminal mutant huntingtin also binds to synaptic vesicles and inhibits their glutamate uptake in vitro. The specific processing and accumulation of toxic fragments of N-terminal huntingtin in HD-affected striatal neurons, especially in their neuronal processes and axonal terminals, may contribute to the selective neuropathology of HD.
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Affiliation(s)
- H Li
- Department of Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
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Johnston H, Koukoulas I, Jeyaseelan K, Armugam A, Earnest L, Baird R, Dawson N, Ferraro T, Wintour EM. Ontogeny of aquaporins 1 and 3 in ovine placenta and fetal membranes. Placenta 2000; 21:88-99. [PMID: 10692256 DOI: 10.1053/plac.1999.0445] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [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: 11/11/2022]
Abstract
A sensitive and highly reproducible method has been used to show that Aquaporin 3 (AQP(3)) mRNA is present in the ovine placenta and chorion from at least 60 days of gestation (term=145-150d) with levels increasing substantially (>16 fold) at 100 days, and remaining constant thereafter. By immuno- and hybridization histochemistry, the epithelial cells expressing AQP(3)were found to be the trophoblast cells. Some AQP(3)was expressed in fibroblasts of the amnion and allantois but none was expressed in the epithelia of these membranes. AQP(1)was expressed in endothelial cells of fetal and maternal blood vessels but not in any epithelial cell of the ovine placenta and fetal membranes. The level of AQP(3)expression is consistent with known ovine placental permeabilities to water, glycerol and urea.
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Affiliation(s)
- H Johnston
- Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, 3052, Australia
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Johnston H, Kneer J, Chackalaparampil I, Yaciuk P, Chrivia J. Identification of a novel SNF2/SWI2 protein family member, SRCAP, which interacts with CREB-binding protein. J Biol Chem 1999; 274:16370-6. [PMID: 10347196 DOI: 10.1074/jbc.274.23.16370] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [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: 11/06/2022] Open
Abstract
The ability of cAMP response-element binding protein (CREB)-binding protein (CBP) to function as a co-activator for a number of transcription factors appears to be mediated by its ability to act as a histone acetyltransferase and through its interaction with a number of other proteins (general transcription factors, histone acetyltransferases, and other co-activators). Here we report that CBP also interacts with a novel ATPase termed Snf2-Related CBP Activator Protein (SRCAP). Consistent with this activity, SRCAP contains the conserved ATPase domain found within members of the Snf2 family. Transfection experiments demonstrate that SRCAP is able to activate transcription when expressed as a Gal-SRCAP chimera and that SRCAP also enhances the ability of CBP to activate transcription. The adenoviral protein E1A was found to disrupt interaction between SRCAP and CBP possibly representing a mechanism for E1A-mediated transcriptional repression.
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Affiliation(s)
- H Johnston
- Department of Pharmacological and Physiological Sciences, Saint Louis University, Saint Louis, Missouri 63104, USA
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Abstract
The aim of this study was to test the hypothesis that the relative insensitivity of the ovine fetal kidney to arginine vasopressin (AVP) is due to low levels of expression of the gene for aquaporin-2 (AQP2) which encodes the AVP-regulated water channel. We report the cloning of the cDNA for the ovine AQP2 which has a major transcript at 4.2 kilobases (kb) and a minor transcript at 1.5 kb, resembling the human gene transcripts. At 40-60 days' (term = 145-150 days'), mRNA levels are very low, detectable only by reverse transcription-polymerase chain reaction (RT-PCR). By Northern blot analysis AQP2 mRNA is detectable at 75 days'. The ratio of AQP2/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA increases approximately 2.4-fold between 100 and 140 days' when it is about 41% of adult values. Both glucocorticoids and the renin-angiotensin system are involved in maturation of renal function. When fetuses at 75 or 85 days of gestation were exposed to high levels of dexamethasone for 2-3 days, mRNAs for both GAPDH and AQP2 doubled, but the ratio was unchanged. Angiotensin I, infused for 3 days at 115-120 days' gestation, increased the AQP2/GAPDH mRNA ratios by twofold (major transcript) and sixfold (minor transcript), which were highly significant (P<0.001). The increasing sensitivity of the ovine fetal kidney to AVP, from 100-140 days of gestation, is largely due to increasing AQP2 gene expression over this period.
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Affiliation(s)
- A Butkus
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Victoria, Australia
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Exall K, Johnston H. Caring for carers coping with stroke. Nurs Times 1999; 95:50-1. [PMID: 10349015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Abstract
We have isolated two alpha-tubulin cDNAs from the leech, Hirudo medicinalis. Both encode putative proteins of 451 amino-acids which differ from each other at only two positions. Southern blotting suggests that there are only two alpha-tubulin genes in the leech. The genes contain two introns and, because of the extremely high homology of the nucleotide sequence from the second intron to the end of the genes, we have inferred that a gene conversion event about 9.5 million years ago has homogenised the Hirudo alpha-tubulin sequences. Using in situ hybridisation to tissue sections, we have shown that the two genes are probably expressed in all neurons of the leech ganglia and that their spatial distribution remains unchanged during neuronal regeneration. The deduced amino-acid sequences of the leech alpha-tubulins show that they have greatest similarity to those from a platyhelminth, echiuran and mollusc with rather less to arthropod alpha-tubulins. The protein sequences of the leech alpha-tubulins have been compared with representatives of those from across all phyla to determine if any specific feature labels certain isotypes of tubulin for neuronal expression.
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Affiliation(s)
- A Fedorov
- Sussex Centre for Neuroscience, Sussex University, Falmer, Brighton BN1 9QG, UK
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White L, Kellie S, Gray E, Toogood I, Waters K, Lockwood L, Macfarlane S, Johnston H. Postoperative chemotherapy in children less than 4 years of age with malignant brain tumors: promising initial response to a VETOPEC-based regimen. A Study of the Australian and New Zealand Children's Cancer Study Group (ANZCCSG). J Pediatr Hematol Oncol 1998; 20:125-30. [PMID: 9544162 DOI: 10.1097/00043426-199803000-00007] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [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: 02/07/2023]
Abstract
PURPOSE Postoperative chemotherapy with indefinite postponement of radiation therapy in children < 4 years old with brain tumors was investigated in a multi-institutional study. PATIENTS AND METHODS From 1991 to 1995, 42 patients aged 3 to 47 months (median 20) with brain tumors were enrolled in a 2-phase chemotherapy protocol: 16 patients had medulloblastoma (MB); 8 had supratentorial primitive neuroectodermal tumor (PNET); 14 had ependymoma; and 4 had other tumors. The initial phase was comprised of 4 courses of the 3-drug regimen: vincristine (VCR), etoposide (VP-16), and intensive cyclophosphamide (CPA) in a previously reported schedule (VETOPEC). The continuation phase was comprised of 2-drug courses: A, CPA + VCR; B, cisplatin + VP-16; and C, carboplatin + VP-16, for a total duration of 64 weeks. RESULTS Response to VETOPEC was evaluable in 28 patients with postresection residual (25) and/or metastatic (1 M2, 6 M3) tumor. There were 9 complete responses (CR) and 9 partial responses (PR) with a combined CR + PR of 64% (95% confidence interval [CI] 44 to 81). In 12 evaluable patients with MB, CR + PR was 82% (48 to 98); in 6 patients with PNET, 50% (12 to 88); and, in 8 patients with ependymoma, 86% (42 to 99). Of 40 patients eligible for further analysis, 6 remain progression-free at a median of 30 months, 14 are alive at a median of 38 months, 29 have progressed at a median of 7 months (range, 2 to 37 months), and 26 have died. The progression-free and overall survival rates at 36 months are estimated to be 11% (95% CI 1 to 22) and 34% (18 to 50), respectively. CONCLUSIONS The initial response to the VETOPEC regimen is encouraging and warrants study of further dose escalation. Survival remains poor with current strategies in this high-risk population.
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Affiliation(s)
- L White
- Sydney Children's Hospital, NSW, Australia
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Ikegami T, Nicholson G, Ikeda H, Ishida A, Johnston H, Wise G, Ouvrier R, Hayasaka K. De novo mutation of the myelin Po gene in Déjérine-Sottas disease (hereditary motor and sensory neuropathy type III): two amino acid insertion after Asp 118. Hum Mutat 1998; Suppl 1:S103-5. [PMID: 9452055 DOI: 10.1002/humu.1380110134] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- T Ikegami
- Department of Pediatrics, Yamagata University School of Medicine, Japan
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Fairbrother DH, Johnston H, Somorjai G. Electron Spectroscopy Studies of the Surface Composition in the H2SO4/H2O Binary System. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960246j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- D. Howard Fairbrother
- Department of Chemistry, University of California, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720
| | - H. Johnston
- Department of Chemistry, University of California, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720
| | - G. Somorjai
- Department of Chemistry, University of California, and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720
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Kolomiets A, Ramakrishnan E, Johnston H, Gimeno-Nogues F, Hurst B, O'Kelly D, Rowland DJ, Shlomo S, White T, Winger J, Yennello SJ. Nuclear temperature of the disassembling source in central heavy-ion collisions from isotope yields. Phys Rev C Nucl Phys 1996; 54:R472-R476. [PMID: 9971431 DOI: 10.1103/physrevc.54.r472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Ikegami T, Nicholson G, Ikeda H, Ishida A, Johnston H, Wise G, Ouvrier R, Hayasaka K. A novel homozygous mutation of the myelin Po gene producing Dejerine-Sottas disease (hereditary motor and sensory neuropathy type III). Biochem Biophys Res Commun 1996; 222:107-10. [PMID: 8630052 DOI: 10.1006/bbrc.1996.0705] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [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: 02/01/2023]
Abstract
We have previously reported that heterozygosity for myelin Po gene mutations were associated with Charcot-Marie-Tooth disease type 1B (CMT1B) or Dejerine-Sottas disease. We investigated the Po gene in a family with clinical Dejerine-Sottas disease and found two children were homozygous for a deletion of Phe 64. The parents were heterozygous first cousins with subclinical CMT1B and slow nerve conduction velocities. These results suggest that the effect of homozygous Phe 64 deletion on impairment of myelination is dosage-dependent. Clinical phenotype and/or myelin impairment may be determined both by the type of mutation and by the dosage of mutated gene.
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Affiliation(s)
- T Ikegami
- Department of Pediatrics, Yamagata University School of Medicine, Japan
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Johnston H, Fonnesbeck DR. A big impact on a small budget. Trustee 1994; 47:16-7. [PMID: 10136516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- H Johnston
- Intermountain Healthcare's Salt Lake Valley Hospitals
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Atterwill C, Davenport-Jones J, Goonetilleke S, Johnston H, Purcell W, Thomas S, West M, Williams S. New models for the In vitro assessment of neurotoxicity in the nervous system and the preliminary validation stages of a ‘tiered-test’ model. Toxicol In Vitro 1993; 7:569-80. [DOI: 10.1016/0887-2333(93)90090-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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