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Khanna O, Hogan E, Alvarez R, Youssef AS. How I do it: hearing preservation in large vestibular schwannomas using vestibular nerve fiber preservation technique. Acta Neurochir (Wien) 2024; 166:105. [PMID: 38403779 DOI: 10.1007/s00701-024-05998-z] [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: 11/01/2023] [Accepted: 01/03/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND To improve hearing function after resection of large vestibular schwannomas, we describe a strategy of vestibular-nerve-fiber preservation. Anatomical considerations and stepwise dissection are described. METHOD Steps include locating the vestibular nerve at the brainstem and identifying a dissection plane between nerve fibers and tumor capsule. Using this plane to mobilize and resect tumor reduced manipulation and maintained vascularity of underlying cochlear and facial nerves. CONCLUSION Preservation of hearing function is feasible in large vestibular schwannomas with vestibular-nerve-fiber preservation. Reducing manipulation and ischemic injury of underlying cochlear and facial nerves thereby helped facilitate hearing preservation, even in large tumors.
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Affiliation(s)
- Omaditya Khanna
- Department of Neurosurgery, University of Colorado Anschutz School of Medicine, Aurora, CO, USA
| | - Elizabeth Hogan
- Department of Neurosurgery, University of Colorado Anschutz School of Medicine, Aurora, CO, USA
| | - Reinier Alvarez
- Department of Neurosurgery, University of Colorado Anschutz School of Medicine, Aurora, CO, USA
| | - A Samy Youssef
- Department of Neurosurgery, University of Colorado Anschutz School of Medicine, Aurora, CO, USA.
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2
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Johnson J, Hogan E, Merrill M, Noss R. An analysis of the impact of annual cancer genetic testing guideline updates on a past patient population. J Genet Couns 2023. [PMID: 37907432 DOI: 10.1002/jgc4.1822] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 09/14/2023] [Accepted: 10/07/2023] [Indexed: 11/02/2023]
Abstract
Germline genetic testing for cancer predisposition genes has become an essential component of cancer treatment and risk reduction. The National Comprehensive Cancer Network (NCCN) releases annual genetic testing guidelines that identify characteristics of patients that could be affected by a hereditary cancer syndrome. These guidelines have broadened over time and the implications for past patients of cancer genetics clinics are not well understood. This study is a retrospective chart review aimed at determining the percentage and characteristics of past patients that meet updated NCCN guidelines (Breast, Ovarian, and Pancreas [BOP] v1.2022 and Colorectal [CRC] v1.2021), patients that attended a follow-up appointment, and patients who went on to receive genetic testing. Clinical data and characteristics were compared between the study population as a whole and the cohort of patients that met updated NCCN guidelines BOP v1.2022 and CRC v1.2021. The study population consisted of 280 patients with 76 (27.1%) patients meeting updated NCCN guidelines BOP v1.2022 and CRC v1.2021. The year of initial cancer genetic counseling appointment was statistically significant (p = 0.023) with patients more likely to meet NCCN guidelines BOP v1.2022 and CRC v1.2021 with earlier initial cancer genetic counseling appointments. In the cohort that met updated NCCN guidelines BOP v1.2022 and CRC v1.2021, the most common reason was a change in the NCCN guidelines (BOP or CRC) (54/76, 71.1%) with triple-negative breast cancer diagnosed at any age being the most impactful guideline change (19/54, 35.2%). Twenty-one patients attended a follow-up appointment (7.5%) and of those that received genetic testing (17/21, 81%) most received negative results (13/17, 61.9%), with one pathogenic, low penetrance result (1/17, 5.9%, CHEK2 p.I157T). Provider-initiated follow-up was attributed to most follow-up appointments (16/21, 76.2%) implying patients do not tend to follow-up on their own. Education to non-genetics providers as well as targeted implementation of follow-up protocols possibly managed by genetic counseling assistants and utilizing electronic medical record (EMR) patient messaging could lead to improved patient follow-up.
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Affiliation(s)
- Jordan Johnson
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Elizabeth Hogan
- Department of Genetics and Genomics, The MetroHealth System, Cleveland, Ohio, USA
| | - Michelle Merrill
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Ryan Noss
- Center for Personalized Genetic Healthcare, Cleveland Clinic Foundation, Cleveland, Ohio, USA
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Alvarez R, Hogan E, Asuzu DT, Wu T, Oshegbo G, McGlotten R, Cortes M, Hayes C, Stratakis CA, Tatsi C, Nieman LK, Chittiboina P. Diurnal Range and Intra-patient Variability of ACTH Is Restored With Remission in Cushing's Disease. J Clin Endocrinol Metab 2023; 108:2812-2820. [PMID: 37261392 PMCID: PMC10584004 DOI: 10.1210/clinem/dgad309] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/02/2023]
Abstract
CONTEXT Single ACTH measurements have limited ability to distinguish patients with Cushing's disease (CD) from those in remission or with other conditions. OBJECTIVE To investigate the changes in ACTH levels before and after transsphenoidal surgery (TSS) to identify trends that could confirm remission from CD and help establish ACTH cutoffs for targeted clinical trials in CD. DESIGN Retrospective analysis of CD patients who underwent TSS from 2005 to -2019. SETTING Referral center. PATIENTS CD patients (n = 253) with ACTH measurements before and after TSS. INTERVENTIONS TSS for CD. MAIN OUTCOME MEASURES Remission after TSS. RESULTS Remission was observed in 223 patients after TSS. Those in remission had higher ACTH variability at AM (P = .02) and PM (P < .001) time points compared to nonremission. The nonremission group had a significantly narrower diurnal range compared to the remission group (P = <.0001). A decrease in plasma ACTH of ≥50% from mean preoperative levels predicted CD remission after TSS, especially when using PM values. The absolute plasma ACTH concentration and ratio of preoperative to postoperative values were significantly associated with nonremission after multivariable logistic regression (adj P < .001 and .001, respectively). CONCLUSIONS Our findings suggest that ACTH variability is suppressed in CD, and remission from CD is associated with the restoration of this variability. Furthermore, a decrease in plasma ACTH by 50% or more may serve as a predictor of remission post-TSS. These insights could guide clinicians in developing rational outcome measures for interventions targeting CD adenomas.
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Affiliation(s)
- Reinier Alvarez
- Neurosurgery Unit for Pituitary and Inheritable Diseases, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus School of Medicine, Aurora, CO, USA
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Elizabeth Hogan
- Neurosurgery Unit for Pituitary and Inheritable Diseases, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus School of Medicine, Aurora, CO, USA
| | - David T Asuzu
- Neurosurgery Unit for Pituitary and Inheritable Diseases, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA
| | - Tianxia Wu
- Clinical Trials Unit, National Institute of Neurological Diseases and Stroke, Bethesda, MD, USA
| | - Gloria Oshegbo
- Biomedical Translational Research Information System, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Raven McGlotten
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michaela Cortes
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Christina Hayes
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Constantine A Stratakis
- Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - Christina Tatsi
- Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - Lynnette K Nieman
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Prashant Chittiboina
- Neurosurgery Unit for Pituitary and Inheritable Diseases, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
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Hubbel A, Hogan E, Matthews A, Goldenberg A. North American genetic counselors' approach to collecting and using ancestry in clinical practice. J Genet Couns 2022; 32:462-474. [PMID: 36445952 DOI: 10.1002/jgc4.1655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/21/2022] [Accepted: 10/28/2022] [Indexed: 12/03/2022]
Abstract
Current guidelines from the National Society of Genetic Counselors (NSGC) recommend that patients' ancestry be obtained when taking a family history. However, no study has explored how consistently genetic counselors obtain or utilize this information. The goals of this study included assessing how genetic counselors collect their patients' ancestry, what factors influence this decision, and how they view the utility of this information. Genetic counselors working in a direct patient care setting in the US or Canada were recruited to participate in an anonymous survey via an NSGC email blast. Most participants (n = 115) obtain information about their patients' ancestry (96.5%), with the most common methods being directly asking the patient (91%) and utilizing intake forms (43.2%). Of participants who ask about ancestry directly, 50.5% always ask about the presence of Ashkenazi Jewish ancestry and 70.3% always ask about additional ancestries, suggesting that for most genetic counselors' collection of ancestry is standard practice. However, the clinical utility of ancestry information is highly variable, with the impact on genetic testing choice being particularly low. A slight majority of participants support a reevaluation of current ancestry guidelines (51.3%), with many participants suggesting that the varying utility of ancestry in different clinical indications/specialties should be incorporated into guidelines. Despite being standard practice for most genetic counselors, no unified approach or standard for how ancestral information should be used in genetic counseling practice was identified.
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Affiliation(s)
- Alexandra Hubbel
- Department of Genetics and Genome Sciences Case Western Reserve University Cleveland Ohio USA
| | - Elizabeth Hogan
- Department of Genetics and Genome Sciences Case Western Reserve University Cleveland Ohio USA
- Division of Genetics and Genomics The MetroHealth System Cleveland Ohio USA
| | - Anne Matthews
- Department of Genetics and Genome Sciences Case Western Reserve University Cleveland Ohio USA
| | - Aaron Goldenberg
- Department of Bioethics Case Western Reserve University Cleveland Ohio USA
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5
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Alvarez R, Mastorakos P, Hogan E, Scott G, Lonser RR, Wiley HE, Chew EY, Chittiboina P. Retrobulbar Hemangioblastomas in von Hippel-Lindau Disease: Clinical Course and Management. Neurosurgery 2021; 88:1012-1020. [PMID: 33442737 DOI: 10.1093/neuros/nyaa565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/04/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Retrobulbar hemangioblastomas involving the optic apparatus in patients with von Hippel-Lindau disease (VHL) are rare, with only 25 reported cases in the literature. OBJECTIVE To analyze the natural history of retrobulbar hemangioblastomas in a large cohort of VHL patients in order to define presentation, progression, and management. METHODS Clinical history and imaging of 250 patients with VHL in an ongoing natural history trial and 1774 patients in a neurosurgical protocol were reviewed. The clinical course, magnetic resonance images, treatment, and outcomes were reviewed for all included patients. RESULTS A total of 18 patients with retrobulbar hemangioblastoma on surveillance magnetic resonance imaging met the inclusion criteria for this study. Of the 17 for whom clinical information was available, 10 patients presented with symptoms related to the hemangioblastoma, and 7 were asymptomatic. The mean tumor volume was larger for symptomatic (810.6 ± 545.5 mm3) compared to asymptomatic patients (307.6 ± 245.5 mm3; P < .05). A total of 5 of the symptomatic patients were treated surgically and all experienced improvement in their symptoms. All 3 symptomatic patients that did not undergo intervention had continued symptom progression. Long-term serial imaging on asymptomatic patients showed that these tumors can remain radiographically stable and asymptomatic for extended periods of time (101.43 ± 71 mo). CONCLUSION This study suggests that retrobulbar hemangioblastomas may remain stable and clinically asymptomatic for long durations. Recent growth and larger tumor volume were associated with symptom occurrence. Surgical treatment of symptomatic retrobulbar hemangioblastomas can be safe and may reverse the associated symptoms.
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Affiliation(s)
- Reinier Alvarez
- Neurosurgery Unit for Pituitary and Inheritable Diseases, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland.,Florida International University Herbert Wertheim College of Medicine, Miami, Florida.,Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
| | - Panagiotis Mastorakos
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland.,Department of Neurosurgery, University of Virginia, Charlottesville, Virginia
| | - Elizabeth Hogan
- Neurosurgery Unit for Pituitary and Inheritable Diseases, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland.,Department of Neurosurgery, George Washington University, Washington, District of Columbia
| | - Gretchen Scott
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
| | - Russell R Lonser
- Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Henry E Wiley
- Division of Epidemiology and Clinical Applications, National Eye Institute, Bethesda, Maryland
| | - Emily Y Chew
- Division of Epidemiology and Clinical Applications, National Eye Institute, Bethesda, Maryland
| | - Prashant Chittiboina
- Neurosurgery Unit for Pituitary and Inheritable Diseases, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland.,Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
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Almeida ND, Lee R, Wei C, Lee D, Asif U, Almeida NC, Klein AL, Hogan E, Sack K, Sherman JH. Coagulation Profile as a Significant Risk Factor for Short-Term Complications and Mortality after Anterior Cervical Discectomy and Fusion. World Neurosurg 2020; 148:e74-e86. [PMID: 33307267 DOI: 10.1016/j.wneu.2020.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 11/24/2019] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cervical degenerative disc disease is the most common indication for anterior cervical discectomy and fusion. Given the possible complications, patients are stratified before anterior cervical discectomy and fusion by preoperative risk factors to optimize treatment. One preoperative factor is a patient's coagulation profile. METHODS The American College of Surgeons-National Surgical Quality Improvement Database was used to identify patient preoperative coagulation profile and postoperative complications. By generating binary logistic regression models, each of the 4 abnormal coagulation categories (bleeding disorder, low platelet count, high partial thromboplastin time, and high international normalized ratio [INR]) were analyzed for their independent impact on increased risk for complications compared with the control cohort. RESULTS A total of 61,977 patients were assessed. The most common abnormal coagulation was abnormal platelet count (n = 2149). The most common postoperative outcome was an extended length of hospital stay among patients with an abnormal coagulation profile relative to the control cohort. After multivariate analysis, patients with an abnormal INR (odds ratio, 2.2 [1.3-3.8]; P = 0.003) or abnormal platelet count (odds ratio, 1.5 [1.2-2.1]; P = 0.003) had a higher chance of having an extended length of hospital stay relative to patients having a normal coagulation profile. Having an abnormal INR was found to be associated with an increased risk for having "Any complication." CONCLUSIONS Our results show significant differences in the incidence rates of a multitude of complications among the 5 groups based on univariate analysis. Patients with any abnormal coagulation disorder had increased rates of developing any complication or having an extended length of hospital stay.
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Affiliation(s)
- Neil D Almeida
- George Washington University School of Medicine and Health Sciences, George Washington University in Washington, Washington, District of Columbia, USA
| | - Ryan Lee
- George Washington University School of Medicine and Health Sciences, George Washington University in Washington, Washington, District of Columbia, USA
| | - Chapman Wei
- George Washington University School of Medicine and Health Sciences, George Washington University in Washington, Washington, District of Columbia, USA
| | - Danny Lee
- George Washington University School of Medicine and Health Sciences, George Washington University in Washington, Washington, District of Columbia, USA
| | - Usman Asif
- George Washington University School of Medicine and Health Sciences, George Washington University in Washington, Washington, District of Columbia, USA
| | - Nyle C Almeida
- University of Oklahoma College of Medicine, University of Oklahoma in Oklahoma City, Oklahoma, USA
| | - Andrea L Klein
- George Washington University School of Medicine and Health Sciences, George Washington University in Washington, Washington, District of Columbia, USA
| | - Elizabeth Hogan
- Department of Neurosurgery, George Washington University Hospital in Washington, Washington, District of Columbia, USA
| | - Kenneth Sack
- Department of Neurosurgery, George Washington University Hospital in Washington, Washington, District of Columbia, USA
| | - Jonathan H Sherman
- Department of Neurological Surgery, West Virginia University, Berkeley Medical Center, Martinsburg, West Virginia, USA.
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Hogan E, Alvarez R, Talagala L, Sarlls J, Merkle H, Koretsky A, Scott G, Butman JA, Chittiboina P. First-in-Human Intraoperative MRI Coil for High Resolution Imaging During Transsphenoidal Surgery. Neurosurgery 2020. [DOI: 10.1093/neuros/nyaa447_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: 11/14/2022] Open
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Carroll C, Conway R, O'Donnell D, Norton C, Hogan E, Browne M, Buckley CM, Kavanagh P, Martin J, Doyle S. Routine testing of close contacts of confirmed COVID-19 cases - National COVID-19 Contact Management Programme, Ireland, May to August 2020. Public Health 2020; 190:147-151. [PMID: 33386140 PMCID: PMC7577651 DOI: 10.1016/j.puhe.2020.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/10/2020] [Indexed: 01/16/2023]
Abstract
OBJECTIVES The objective of this study was to inform public health practitioners who are designing, adapting and implementing testing and tracing strategies for Coronavirus disease (COVID-19) control. STUDY DESIGN The study design is monitoring and evaluation of a national public health protection programme. METHODS All close contacts of laboratory-confirmed cases of COVID-19 identified between the 19th May and 2nd August were included; secondary attack rates and numbers needed to test were estimated. RESULTS Four thousand five hundred eighty six of 7272 (63%) close contacts of cases were tested with at least one test. The secondary attack rate in close contacts who were tested was 7% (95% Confidence Interval [CI]: 6.3 - 7.8%). At the 'day 0' test, 14.6% (95% CI: 11.6-17.6%) of symptomatic close contacts tested positive compared with 5.2% (95% CI: 4.4-5.9%) of asymptomatic close contacts. CONCLUSIONS The application of additional symptom-based criteria for testing in this high-incidence population (close contacts) is of limited utility because of the low negative predictive value of absence of symptoms.
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Affiliation(s)
- C Carroll
- Joint First Author; COVID-19 Contact Management Programme, Health Service Executive, Ireland
| | - R Conway
- Joint First Author; COVID-19 Contact Management Programme, Health Service Executive, Ireland.
| | - D O'Donnell
- COVID-19 Contact Management Programme, Health Service Executive, Ireland
| | - C Norton
- COVID-19 Contact Management Programme, Health Service Executive, Ireland
| | - E Hogan
- COVID-19 Contact Management Programme, Health Service Executive, Ireland; National Quality Improvement Team, Health Service Executive, Ireland
| | - M Browne
- COVID-19 Contact Management Programme, Health Service Executive, Ireland; National Quality Improvement Team, Health Service Executive, Ireland
| | - C M Buckley
- COVID-19 Contact Management Programme, Health Service Executive, Ireland; School of Public Health, University College Cork, Cork, Ireland
| | - P Kavanagh
- COVID-19 Contact Management Programme, Health Service Executive, Ireland; Health Intelligence Unit Strategic Planning and Transformation, Dublin, Ireland; Division of Population Health Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - J Martin
- COVID-19 Contact Management Programme, Health Service Executive, Ireland; National Quality Improvement Team, Health Service Executive, Ireland
| | - S Doyle
- COVID-19 Contact Management Programme, Health Service Executive, Ireland
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Alvarez R, Hogan E, Wu T, Stratakis CA, Nieman LK, Chittiboina P. OR23-01 Intrapatient ACTH Variability in Cushing’s Disease: Prognostic Significance. J Endocr Soc 2020. [PMCID: PMC7207552 DOI: 10.1210/jendso/bvaa046.1319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Introduction: In patients with Cushing’s Disease (CD), intrapatient variability of hormone measurements creates significant clinical challenges, therefore multiple measurements are recommended.1 Urinary and salivary cortisol variation has been well described. However, intrapatient variation of adrenocorticotropic hormone (ACTH) in CD remains unknown. In CD patients, ACTH levels are inherently elevated from baseline but the coefficient of diurnal variation is reduced.2Additionally, at each diurnal time point, these exists a significant variation around the mean for the ACTH levels. In this study, we first analyzed the intrapatient variablility of ACTH at each diurnal timepoint in patients with CD. CD is primarily a disorder of ACTH excess, and treatment directed at pituitary adenomas would presumably perturb ACTH levels prior to affecting serum or urine cortisol. We hypothesized that the coefficient of variation at each diurnal time-point can help predict remission from CD following surgery.
Methods: We conducted a retrospective review of patients (n = 645) who had histopathologically confirmed diagnosis of CD from 2005-2019 (NCT NCT00060541). We selected patients that had ≥ 3 plasma ACTH values over a 7 day span prior to surgical or medical intervention. We grouped the ACTH measurements into morning (AM) and midnight (PM) values to account for diurnal variation in ACTH secretion. We then analyzed post-operative hormone measurements performed every 6 hours prior to administration of replacement corticosteroids. Remission was assigned to patients with nadir serum cortisol level ≤5 mcg/dL within ten days post-operatively3,4.
Results: We found 54 patients with multiple PM (n = 27) and AM (n = 41) ACTH measurements within a 7 day span. We found that the median coefficient of variation (CV) of intra-patient variability was 19.7% (N=41) (95% CI:12.5-27.5) for the AM and was 24% (N=27) (95% CI: 9.6-31.8) for the PM. Age, the number of tests, or the length of test period were not correlated with CV or absolute levels of ACTH. The intraclass correlation coefficient (ICC) of the AM data set was 0.59 and the PM data set was 0.79 which demonstrates a good and excellent reliability respectively. We found that that, in general, 30-60% decrease from pre-operative ACTH levels predicted remission from CD. ACTH decrease >50% on POD2 and 3 had 100% specificity and sensitivity in predicting remission. The decrease in ACTH preceded cortisol nadir in 3/10 patients by 24 hours.
Conclusion: We found significant intra-patient variability in plasma levels of ACTH at individual diurnal timepoints in CD patients. We also found that the change in ACTH >50% on POD2 or 3 is an excellent predictor of remission from CD.
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Affiliation(s)
- Reinier Alvarez
- National Institute of Neurological Diseases and Stroke, Bethesda, MD, USA
| | - Elizabeth Hogan
- National Institute of Neurological Diseases and Stroke, Bethesda, MD, USA
| | - Tianxia Wu
- National Institute of Neurological Diseases and Stroke, Bethesda, MD, USA
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Hogan E, Vora D, Sherman JH. A minimally invasive surgical approach for the treatment of piriformis syndrome: a case series. Chin Neurosurg J 2020; 6:8. [PMID: 32922937 PMCID: PMC7398220 DOI: 10.1186/s41016-020-00189-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 03/18/2020] [Indexed: 11/10/2022] Open
Abstract
Background Piriformis syndrome accounts for approximately 6% of patients who present with sciatic pain. There are many treatment options ranging from physical therapy, to trigger point injections, to surgical intervention. We discuss a surgical method that represents a minimally invasive technique for the treatment of piriformis syndrome. Methods We describe a novel operative approach and technique for release of the piriformis muscle in the treatment of piriformis syndrome. Described are the preoperative planning, incision and approach, and technique for identifying and releasing the piriformis muscle. Results Three patients were treated for piriformis syndrome using the described technique. Each patient displayed successful relief of their symptoms immediately following the surgical procedure and at delayed follow-up. Conclusion Early experience with our method of piriformis release suggests that it is well suited for the treatment of piriformis syndrome. The novel integration of pre-operative trigger point localization coupled with intraoperative neuromonitoring allows effective pain relief with minimal morbidity.
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Affiliation(s)
- Elizabeth Hogan
- Department of Neurosurgery, the George Washington University, 2150 Pennsylvania Avenue, NWSuite 7-420, Washington, DC 20037 USA
| | - Darshan Vora
- Medicine and Health Sciences, the George Washington University, Washington, DC USA
| | - Jonathan H Sherman
- Department of Neurosurgery, the George Washington University, 2150 Pennsylvania Avenue, NWSuite 7-420, Washington, DC 20037 USA
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Richardson K, Asmutis-Silvia R, Drinkwin J, Gilardi KVK, Giskes I, Jones G, O'Brien K, Pragnell-Raasch H, Ludwig L, Antonelis K, Barco S, Henry A, Knowlton A, Landry S, Mattila D, MacDonald K, Moore M, Morgan J, Robbins J, van der Hoop J, Hogan E. Building evidence around ghost gear: Global trends and analysis for sustainable solutions at scale. Mar Pollut Bull 2019; 138:222-229. [PMID: 30660266 DOI: 10.1016/j.marpolbul.2018.11.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 06/21/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
Abandoned, lost or discarded fishing gear (ALDFG) comprises a significant amount of global marine debris, with diverse impacts to marine environments, wildlife, and the fishing industry. Building evidence on ALDFG is critical to holistically understand the marine debris issue, and to inform the development of solutions that reduce amounts of ALDFG sources and recover existing gear. Substantial work has been and continues to be undertaken around the world to collect data on ALDFG, much of which remains unpublished. To provide a global picture of data on ALDFG, we organized a technical session that brought together seven ALDFG leaders to share their expertise in data collection, retrieval, and awareness-raising. This paper summarizes the technical session to highlight: 1) case studies that feature innovative approaches to ALDFG data collection and retrieval; 2) examples of opportunities to fill data gaps and improve our understanding of wildlife ingestion of and entanglement in ALDFG; and 3) awareness-raising through the development of a publicly accessible global ALDFG database.
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Affiliation(s)
- Kelsey Richardson
- University of Tasmania, Commonwealth Scientific and Industrial Research Organisation (CSIRO), 3-4 Castray Esplanade, Hobart, TAS 7000, Australia.
| | | | - Joan Drinkwin
- Natural Resources Consultants, Inc., 4039 21st Ave. West, Ste. 404, Seattle, WA 98199, USA.
| | - Kirsten V K Gilardi
- Karen C. Drayer Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA.
| | - Ingrid Giskes
- World Animal Protection, Level 2, 120 Christie Street, St Leonards, NSW 2065, Australia.
| | - Gideon Jones
- Emerald Sea Protection Society, 3144 West 7th Avenue, Vancouver, BC V6K2A1, Canada.
| | - Kevin O'Brien
- NOAA Pacific Islands Fisheries Science Center, Joint Institute of Marine and Atmospheric Research, NOAA Inouye Regional Center, 1845 Wasp Blvd., Bldg. #176, Honolulu, HI 96818, USA.
| | | | - Laura Ludwig
- Center for Coastal Studies, 5 Holway Avenue, Provincetown, MA 02657, USA.
| | - Kyle Antonelis
- Natural Resources Consultants, Inc., 4039 21st Ave. West, Ste. 404, Seattle, WA 98199, USA.
| | - Susan Barco
- Virginia Aquarium and Marine Science Center, 717 General Booth Blvd, Virginia Beach, VA 23451, USA.
| | - Allison Henry
- NOAA Northeast Fisheries Science Center, 166 Water Street, Woods Hole, MA 02543, USA.
| | - Amy Knowlton
- New England Aquarium, 1 Central Wharf, Boston, MA 02110, USA.
| | - Scott Landry
- Center for Coastal Studies, 5 Holway Avenue, Provincetown, MA 02657, USA.
| | - David Mattila
- Center for Coastal Studies, 5 Holway Avenue, Provincetown, MA 02657, USA.
| | - Kristen MacDonald
- Karen C. Drayer Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA
| | - Michael Moore
- Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543, USA.
| | - Jason Morgan
- Northwest Straits Foundation, 1155 N. State Street Ste. 402, Bellingham, WA 98225, USA.
| | - Jooke Robbins
- Center for Coastal Studies, 5 Holway Avenue, Provincetown, MA 02657, USA.
| | - Julie van der Hoop
- Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543, USA; Zoophysiology, Department of Bioscience, Aarhus University, C. F. Møllers Alle 3, 8000 Aarhus C, Denmark.
| | - Elizabeth Hogan
- World Animal Protection, 450 7th Ave., 31st Floor, New York, NY 10123, United States.
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Hogan E, Almira-Suarez I, Li S, Collins SP, Jean WC. Clinical Management of Prostate Cancer Metastasis to Pineal Gland: Case Report and Review of Literature. World Neurosurg 2018; 122:464-468. [PMID: 30476672 DOI: 10.1016/j.wneu.2018.11.111] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 10/17/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Prostate cancer is the most common cancer among American men, with an incidence of approximately 233,000 cases per year. Intracranial metastases are rare and, specifically, metastasis to the pineal gland has only been reported in 2 postmortem cases in the literature. CASE DESCRIPTION We present the first documented case of confirmed prostate cancer metastasis to the pineal gland in a living patient. The patient underwent an endoscopic third ventriculostomy and pineal lesion biopsy with complete resolution of his hydrocephalus and presenting symptoms. His biopsy results confirmed the prostate origin of the metastasis, and he subsequently underwent stereotactic radiosurgery for treatment of this lesion. CONCLUSIONS This is the first report of the clinical management of metastatic prostate cancer to the pineal region and description of the clinical outcome. Although prostate cancer is the most common cancer in American men, metastasis to the pineal has only been reported twice from autopsy examinations. Overall, pineal tumors in the geriatric population are exceedingly rare and the age and comorbidities in this patient made management quite unique.
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Affiliation(s)
- Elizabeth Hogan
- Department of Neurological Surgery, George Washington University, Washington, D.C., USA
| | - Isabel Almira-Suarez
- Department of Pathology, Children's National Medical Center, Washington, D.C., USA
| | - Siyuan Li
- Department of Radiation Medicine, Georgetown University, Washington, D.C., USA
| | - Sean P Collins
- Department of Radiation Medicine, Georgetown University, Washington, D.C., USA
| | - Walter C Jean
- Department of Neurological Surgery, George Washington University, Washington, D.C., USA.
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Reisner A, Popoli DM, Burns TG, Marshall DL, Jain S, Hall LB, Vova JA, Kroll S, Weselman BC, Palasis S, Hayes LL, Clark GH, Speake KM, Holbrook BH, Wiskind RH, Licata RM, Ono KE, Hogan E, Chern JJ, DeGrauw T. The Central Role of Community-Practicing Pediatricians in Contemporary Concussion Care: A Case Study of Children's Healthcare of Atlanta's Concussion Program. Clin Pediatr (Phila) 2015; 54:1031-7. [PMID: 25715824 DOI: 10.1177/0009922815573468] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Andrew Reisner
- Children's Healthcare of Atlanta, Atlanta, GA, USA Emory University, Atlanta, GA, USA
| | | | - Thomas G Burns
- Children's Healthcare of Atlanta, Atlanta, GA, USA Emory University, Atlanta, GA, USA
| | | | - Shabnam Jain
- Children's Healthcare of Atlanta, Atlanta, GA, USA Emory University, Atlanta, GA, USA
| | - Larry B Hall
- Children's Healthcare of Atlanta, Atlanta, GA, USA
| | | | - Steve Kroll
- Children's Orthopaedics of Atlanta, Atlanta, GA, USA
| | | | | | | | | | | | | | | | | | - Kim E Ono
- Children's Healthcare of Atlanta, Atlanta, GA, USA Emory University, Atlanta, GA, USA
| | | | - Joshua J Chern
- Children's Healthcare of Atlanta, Atlanta, GA, USA Emory University, Atlanta, GA, USA
| | - Ton DeGrauw
- Children's Healthcare of Atlanta, Atlanta, GA, USA Emory University, Atlanta, GA, USA
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Abstract
OBJECTIVES There are little data regarding the practice of electroconvulsive therapy (ECT) in correctional settings in the United States. A survey was conducted to study the current practice of ECT in US prisons. We hypothesize that ECT is underutilized in the correctional setting. We also review the ethical aspects of using ECT for the treatment of mental illness in the prison population. METHODS A 12-question survey via a Survey Monkey link was emailed to chiefs of psychiatry, or the equivalent, of each state's department of corrections. We examined the frequency of Likert-type responses, tabulated individual comments for qualitative review, and grouped for comparison. RESULTS Email contacts for chiefs of psychiatry, or the equivalent, for the department of corrections in 45 states (90%) were obtained and a survey link was sent. Thirty-one (68.9%) of 45 responded to the survey. Respondent estimates of the number of inmates with mental illness in 31 prison systems varied from less than 500 to more than 4500. Of these 31, 12 (38.7%) had more than 4500 inmates with mental illness. Four systems reported the use of ECT within the last 5 years. Of those, one reported use in the last 1 to 6 months, and 3 reported use in the last 2 to 5 years. Of these 4 prison systems, all felt that they had up to 10 patients who would benefit if ECT continued to be offered or became available in the future. None of these systems provided ECT within the prison. The inmates were referred to a local state psychiatric facility, a university hospital, or other institutions. The reasons for not using ECT as reported by the respondents are grouped under subheadings of stigma, ethical concerns, logistical concerns, and others. CONCLUSIONS Considering the high prevalence of mental illness in prisons, one might expect a high prevalence of ECT responsive mental illness and, hence, provision of ECT to some prisoners with mental illness. However, our survey suggests that the use of ECT in prisons in the United States is low. Stigma, ethical concerns, and logistical concerns were the main hindrances for providing ECT to prisoners with mental illness. Given that ECT is the standard of care in certain clinical scenarios, physicians are obligated to offer such treatment to inmates when necessary. It can be argued that failure of the prison to offer the standard of care is unethical and unconstitutional.
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Affiliation(s)
- Sandarsh Surya
- From the *Department of Psychiatry and Health Behavior, Medical College of Georgia, Georgia Regents University, Augusta, GA and †Department of Philosophy and Center for Bioethics, Health and Society, Wake Forest University, Winston-Salem, NC
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McCall-Brown AN, Felberg R, Eboras OJ, Bertsch L, Volturo J, Hogan E. Abstract T MP108: Decreasing Door-to-Needle Time a Collaborative Approach. Stroke 2015. [DOI: 10.1161/str.46.suppl_1.tmp108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The Target Stroke guidelines recommend treatment initiation within 60 minutes of patients’ arrival in the emergency department (ED). In May 2012 we began an indepth review of our acute stroke (“Code Gray”) care process in an effort to improve our door to needle time (DTN).
Objectives:
To decrease the DTN time to 45 minutes or less, treating 50% or more of our patients within that time frame.
Methods:
A multi-disciplinary performance improvement team was formed and trained in Six Sigma methodology. A retrospective review of baseline data identified 75 data points spanning the 19- month period January 2011 to July 2012. A pilot study was initiated, which included tPA-eligible patients arriving in the ED who could be treated within 3-4.5 hours from the onset of symptoms.
Results:
Baseline data indicated that we achieved theTarget Stroke recommendations for 50% of eligible patients. The mean DTN time was 61 minutes, and standard deviation of 18 minutes. The average “Door to CT results” was 29 minutes. However there was significant variation in “Door to CT results” and “CT Results to Drug” times, contributing significantly to delays in DTN. It was determined that bringing the patient directly to CT on the EMS stretcher would be a high impact intervention. This new process incorporated more timely patient registration and immediate assessment by the ED physician. In our pilot group consisting of the 44 patients where pre-notification was available, the, average DTN time was 38 minutes, with the lowest DTN of 14 minutes. An additional 29 patients, for whom pre-notification was not provided, were not included in the pilot but benefited from this process change with an average DTN of 49 minutes. Average time for “Door to CT results” has decreased from the baseline average of 29 minutes down to 7 minutes for the patients in the pilot and to 20 minutes for all patients.
Conclusion:
We have made a statistical difference between our baseline and our pilot data. We have decreased our average time by 23 minutes for those patients that we received pre-notification, and we are currently 18 minutes under the national average for all patients combined. While the pilot has been limited to patients with pre-notification, it clearly has benefited all stroke patients.
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Cesmebasi A, Loukas M, Hogan E, Kralovic S, Tubbs RS, Cohen-Gadol AA. The Chiari malformations: a review with emphasis on anatomical traits. Clin Anat 2014; 28:184-94. [PMID: 25065525 DOI: 10.1002/ca.22442] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [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: 01/14/2011] [Revised: 06/16/2014] [Accepted: 07/02/2014] [Indexed: 11/06/2022]
Abstract
Hindbrain herniations come in many forms and have been further subdivided as their original descriptions. For cerebellar tonsillar ectopia, they can be divided into two categories, acquired and congenital. Acquired hindbrain herniations are due to increased intracranial pressure caused by certain conditions such as trauma or brain tumor. Although the mechanism for their formation is not clear, congenital hindbrain herniation makes up the majority of these congenital malformations. Furthermore, these malformations are often found to harbor additional anatomical derailments in addition to the hindbrain herniation whether it be the cerebellar tonsils (Chiari I malformation) or the cerebellar vermis (Chiari II malformation). This article reviews these forms of cerebellar ectopia and describes the details of their anomalous anatomy. Moreover, this article compares and contrasts the differing embryological theories found in this literature.
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Affiliation(s)
- Alper Cesmebasi
- Department of Anatomical Sciences, St. George's University, St. George's, Grenada, West Indies
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18
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Song YB, Watanabe K, Hogan E, D'Antoni AV, Dilandro AC, Apaydin N, Loukas M, Shoja MM, Tubbs RS. The fibular collateral ligament of the knee: a detailed review. Clin Anat 2014; 27:789-97. [PMID: 24948572 DOI: 10.1002/ca.22301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [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: 05/30/2012] [Revised: 05/03/2013] [Accepted: 06/26/2013] [Indexed: 01/13/2023]
Abstract
The fibular collateral ligament (FCL) is one of the larger ligaments of the knee. The FCL, along with the popliteus tendon, arcuate popliteal ligament, and joint capsule, make up the posterolateral corner of the knee. Recently, there has there been an increased awareness and research on the structures of the posterolateral corner of the knee, particularly the FCL. Studying the detailed structure of the FCL may provide a better understanding that can lead to better diagnosis and treatments following injury. Therefore, this article reviews the FCL, which appears to be the primary restraint to varus rotation but is poorly oriented to resist external rotation of the knee.
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Affiliation(s)
- Young-Bin Song
- Pediatric Neurosurgery Children's of Alabama, Birmingham, AL
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Clark D, Clark D, Hogan E, Kroscher K, Dilger A. Expression of insulin‐like growth factor family members in myostatin null mice (1032.3). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.1032.3] [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]
Affiliation(s)
- Daniel Clark
- Animal SciencesUniversity of Illinois at Urbana‐ChampaignURBANAILUnited States
| | - Diana Clark
- Animal SciencesUniversity of Illinois at Urbana‐ChampaignURBANAILUnited States
| | - Elizabeth Hogan
- Animal SciencesUniversity of Illinois at Urbana‐ChampaignURBANAILUnited States
| | - Kellie Kroscher
- Animal SciencesUniversity of Illinois at Urbana‐ChampaignURBANAILUnited States
| | - Anna Dilger
- Animal SciencesUniversity of Illinois at Urbana‐ChampaignURBANAILUnited States
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Tubbs RS, Griessenauer CJ, Hogan E, Loukas M, Cohen-Gadol AA. Neural interconnections between portio minor and portio major at the porus trigeminus: Application to failed surgical treatment of trigeminal neuralgia. Clin Anat 2013; 27:94-6. [DOI: 10.1002/ca.22299] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 06/07/2013] [Accepted: 06/21/2013] [Indexed: 11/11/2022]
Affiliation(s)
- R. Shane Tubbs
- Department of Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
- Section of Neurosurgery; University of Alabama; Birmingham Alabama
| | | | - Elizabeth Hogan
- Department of Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - Marios Loukas
- Department of Anatomical Sciences; St. George's University; St. George's Grenada
| | - Aaron A. Cohen-Gadol
- Department of Neurological Surgery; Goodman Campbell Brain and Spine; Indiana University School of Medicine; Indianapolis Indiana
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Bosmia AN, Tubbs RS, Hogan E, Bohnstedt BN, Denardo AJ, Loukas M, Cohen-Gadol AA. Blood Supply to the human spinal cord: Part II. Imaging and pathology. Clin Anat 2013; 28:65-74. [DOI: 10.1002/ca.22284] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/15/2013] [Accepted: 05/27/2013] [Indexed: 12/20/2022]
Affiliation(s)
- Anand N. Bosmia
- Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - R. Shane Tubbs
- Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - Elizabeth Hogan
- Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - Bradley N. Bohnstedt
- Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine; Indianapolis Indiana
| | - Andrew J. Denardo
- Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine; Indianapolis Indiana
| | - Marios Loukas
- Department of Anatomical Sciences; St. George's University; Grenada
| | - Aaron A. Cohen-Gadol
- Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine; Indianapolis Indiana
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Abstract
INTRODUCTION Proboscis lateralis is a rare congenitally acquired facial abnormality characterized by a soft-tissue tube- or trunk-like appendage projecting from the surface of the face, most frequently rooted in the medial canthal region. Proboscis lateralis is generally associated with a wide range of concomitant craniofacial anomalies, giving rise to multiple theories describing the embryological pathogenesis and various classification systems to account for the pathological associations. RESULTS/CONCLUSION This paper provides a literature review of the rare manifestations of proboscis lateralis and represents a summary of current literature related to embryological pathogenesis, definitive diagnosis, and surgical management approaches.
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Affiliation(s)
- S Martin
- Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, West Indies
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Abstract
BACKGROUND Masses of the lateral skull are not uncommon and include lipomas and epidermoids. However, meningoceles of the lateral skull are very rare and are often misdiagnosed. Even rarer are atretic encephaloceles of this region. ILLUSTRATIVE CASE We report a newborn with a right atretic encephalocele of the asterion. Lesions of the anterolateral and posterolateral fontanelles should include lateral cephaloceles/encephaloceles in the differential diagnosis. The literature and embryology of these rare entities are discussed.
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Affiliation(s)
- R Shane Tubbs
- Pediatric Neurosurgery, Children's Hospital, 1600 7th Avenue South ACC 400, Birmingham, AL 35233, USA.
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24
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Zentall TR, Hogan E. Same/different concept learning in the pigeon: the effect of negative instances and prior adaptation to transfer stimuli. J Exp Anal Behav 2010; 30:177-86. [PMID: 16812097 PMCID: PMC1332713 DOI: 10.1901/jeab.1978.30-177] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Pigeons were trained on a matching-to-sample or oddity-from-sample task with shapes (circle and plus). Half of each group was exposed to "negative instance" trials i.e., for matching birds, neither comparison key matched the sample, and for oddity birds both comparison keys matched the sample. When all birds were transferred to a new task involving colors (red and green), nonshifted birds (transferred from matching to matching, or oddity to oddity) performed significantly better than shifted birds (transferred from matching to oddity, or oddity to matching), but only if they had experienced negative instances of the training concept. When all birds were exposed to negative instances of the transfer task and then transferred to a new color task (yellow and blue), dramatic transfer effects were observed. The effect of pre-exposure to the yellow and blue colors, in order to reduce transfer-stimulus novelty, had a minor effect on transfer.
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Burleigh MR, Hogan E, Dobbie PD, Napiwotzki R, Maxted PFL. A near-infrared spectroscopic detection of the brown dwarf in the post common envelope binary WD 0137-349. ACTA ACUST UNITED AC 2006. [DOI: 10.1111/j.1745-3933.2006.00242.x] [Citation(s) in RCA: 37] [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: 11/27/2022]
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Tarpey I, Orbell SJ, Britton P, Casais R, Hodgson T, Lin F, Hogan E, Cavanagh D. Safety and efficacy of an infectious bronchitis virus used for chicken embryo vaccination. Vaccine 2006; 24:6830-8. [PMID: 16860445 PMCID: PMC7126498 DOI: 10.1016/j.vaccine.2006.06.040] [Citation(s) in RCA: 31] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 06/19/2006] [Accepted: 06/20/2006] [Indexed: 11/28/2022]
Abstract
Commercial vaccines for in ovo vaccination have not yet been developed for infectious bronchitis virus (IBV), the major coronavirus in the poultry industry. Recombinant IBVs based on the Beaudette strain expressing the Beaudette spike protein (Beau-R) or that from the virulent M41 strain (BeauR-M41(S)) were assessed for their potential as prototype vaccines for application to 18-day-old embryos. Pathogenicity was assessed by observing the effect on hatchability, and/or the production of nasal discharge and/or the effects on ciliary activity in the trachea at various time points post hatch. In contrast to commercial IBV vaccines given in ovo, the Beau-R and BeauR-M41(S) strains did not reduce hatchability or cause nasal discharge, and caused minimal damage to the ciliated epithelium of the trachea. The presence of the spike protein from a virulent virus did not increase the pathogenicity of the virus according to the criteria used. Assessment of the BeauR-M41(S) strain for efficacy showed that it protected up to 90% of chicks against challenge with virulent IB virus (M41) in a dose dependent manner. Further egg passage of the BeauR-M41(S) strain (BeauR-M41(S) EP10) did not increase its pathogenicity though it did improve its efficacy, based on serology and protection against a virulent challenge. BeauR-M41(S) EP10 was more efficacious than BeauR-M41(S) protecting more birds against virulent challenge and providing a better serological antibody response. BeauR-M41(S) EP10 induced a serological response similar to that of a commercial vaccine given at day-old though the commercial vaccine provided slightly higher efficacy. These results are promising for the development of embryo safe efficacious IBV vaccines for in ovo application.
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Affiliation(s)
- I Tarpey
- Intervet UK, Walton Manor, Walton, Milton Keynes, Bucks, UK.
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Foster N, Holland H, Hogan E. Improving the quality of the health care work place: implications for workers and patients. Introduction. Jt Comm J Qual Improv 2001; 27:443. [PMID: 11556253 DOI: 10.1016/s1070-3241(01)27038-2] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- N Foster
- Agency for Healthcare Research and Quality, 2101 E. Jefferson St, Suite 600, Rockville, MD 20852, USA.
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Abstract
Although general features of chromosome movement during the cell cycle are conserved among all eukaryotic cells, particular aspects vary between organisms. Understanding the basis for these variations should provide significant insight into the mechanism of chromosome movement. In this context, establishing the types of chromosome movement in the budding yeast Saccharomyces cerevisiae is important since the complexes that mediate chromosome movement (microtubule organizing centers, spindles, and kinetochores) appear much simpler in this organism than in many other eukaryotic cells. We have used fluorescence in situ hybridization to begin an analysis of chromosome movement in budding yeast. Our results demonstrate that the position of yeast centromeres changes as a function of the cell cycle in a manner similar to other eukaryotes. Centromeres are skewed to the side of the nucleus containing the spindle pole in G1; away from the poles in mid-M and clustered near the poles in anaphase and telophase. The change in position of the centromeres relative to the spindle poles supports the existence of anaphase A in budding yeast. In addition, an anaphase A-like activity independent of anaphase B was demonstrated by following the change in centromere position in telophase-arrested cells upon depolymerization and subsequent repolymerization of microtubules. The roles of anaphase A activity and G1 centromere positioning in the segregation of budding yeast chromosomes are discussed. The fluorescence in situ hybridization methodology and experimental strategies described in this study provide powerful new tools to analyze mutants defective in specific kinesin-like molecules, spindle components, and centromere factors, thereby elucidating the mechanism of chromosome movement.
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Affiliation(s)
- V Guacci
- Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21210, USA
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30
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Hogan E. Diagnosis and Management of Disorders of the Spinal Cord. Neurology 1997. [DOI: 10.1212/wnl.48.2.559] [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: 11/15/2022] Open
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Strunnikov AV, Hogan E, Koshland D. SMC2, a Saccharomyces cerevisiae gene essential for chromosome segregation and condensation, defines a subgroup within the SMC family. Genes Dev 1995; 9:587-99. [PMID: 7698648 DOI: 10.1101/gad.9.5.587] [Citation(s) in RCA: 287] [Impact Index Per Article: 9.9] [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: 01/26/2023]
Abstract
We characterized the SMC2 (structural maintenance of chromosomes) gene that encodes a new Saccharomyces cerevisiae member of the growing family of SMC proteins. This family of evolutionary conserved proteins was introduced with identification of SMC1, a gene essential for chromosome segregation in budding yeast. The analysis of the putative structure of the Smc2 protein (Smc2p) suggests that it defines a distinct subgroup within the SMC family. This subgroup includes the ScII, XCAPE, and cut14 proteins characterized concurrently. Smc2p is a nuclear, 135-kD protein that is essential for vegetative growth. The temperature-sensitive mutation, smc2-6, confers a defect in chromosome segregation and causes partial chromosome decondensation in cells arrested in mitosis. The Smc2p molecules are able to form complexes in vivo both with Smc1p and with themselves, suggesting that they can assemble into a multimeric structure. In this study we present the first evidence that two proteins belonging to two different subgroups within the SMC family carry nonredundant biological functions. Based on genetic, biochemical, and evolutionary data we propose that the SMC family is a group of prokaryotic and eukaryotic chromosomal proteins that are likely to be one of the key components in establishing the ordered structure of chromosomes.
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Affiliation(s)
- A V Strunnikov
- Carnegie Institution of Washington, Department of Embryology, Baltimore, Maryland 21210
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Abstract
We have developed a fluorescent in situ hybridization (FISH) method to examine the structure of both natural chromosomes and small artificial chromosomes during the mitotic cycle of budding yeast. Our results suggest that the pairing of sister chromatids: (a) occurs near the centromere and at multiple places along the chromosome arm as has been observed in other eukaryotic cells; (b) is maintained in the absence of catenation between sister DNA molecules; and (c) is independent of large blocks of repetitive DNA commonly associated with heterochromatin. Condensation of a unique region of chromosome XVI and the highly repetitive ribosomal DNA (rDNA) cluster from chromosome XII were also examined in budding yeast. Interphase chromosomes were condensed 80-fold relative to B form DNA, similar to what has been observed in other eukaryotes, suggesting that the structure of interphase chromosomes may be conserved among eukaryotes. While additional condensation of budding yeast chromosomes were observed during mitosis, the level of condensation was less than that observed for human mitotic chromosomes. At most stages of the cell cycle, both unique and repetitive sequences were either condensed or decondensed. However, in cells arrested in late mitosis (M) by a cdc15 mutation, the unique DNA appeared decondensed while the repetitive rDNA region appeared condensed, suggesting that the condensation state of separate regions of the genome may be regulated differently. The ability to monitor the pairing and condensation of sister chromatids in budding yeast should facilitate the molecular analysis of these processes as well as provide two new landmarks for evaluating the function of important cell cycle regulators like p34 kinases and cyclins. Finally our FISH method provides a new tool to analyze centromeres, telomeres, and gene expression in budding yeast.
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Affiliation(s)
- V Guacci
- Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21210
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Guacci V, Yamamoto A, Strunnikov A, Kingsbury J, Hogan E, Meluh P, Koshland D. Structure and function of chromosomes in mitosis of budding yeast. Cold Spring Harb Symp Quant Biol 1993; 58:677-85. [PMID: 7956084 DOI: 10.1101/sqb.1993.058.01.075] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- V Guacci
- Department of Embryology, Carnegie Institute of Washington, Baltimore, Maryland 21210
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Hogan E, Koshland D. Addition of extra origins of replication to a minichromosome suppresses its mitotic loss in cdc6 and cdc14 mutants of Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 1992; 89:3098-102. [PMID: 1557417 PMCID: PMC48811 DOI: 10.1073/pnas.89.7.3098] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.5] [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: 12/27/2022] Open
Abstract
Many cell division cycle (cdc) mutants of Saccharomyces cerevisiae exhibit elevated mitotic loss of pDK243, a 14-kilobase minichromosome with a centromere and one autonomous replicating sequence (ARS). Tandem copies of different ARSs were added to pDK243. The addition of these ARS clusters to pDK243 had no effect on its mitotic loss in cdc7 (protein kinase), cdc9 (DNA ligase), or cdc16 or cdc17 (DNA polymerase) mutants. However, in cdc6 and cdc14 mutants, the mitotic loss of pDK243 with an ARS cluster was suppressed by a factor of 6-8 compared to pDK243 without the cluster. This suppression was dependent upon the number of ARSs in the cluster and the integrity of the ARS consensus sequence in each ARS of the cluster. ARSs are known to be DNA replication origins. Therefore, the suppression of mini-chromosome loss by ARSs in cdc6 and cdc14 mutants suggests that these mutants are defective in the initiation of DNA replication. Since the CDC6 protein appears to act at the G1/S phase transition, the CDC6 protein may be a factor required at the beginning of S phase to initiate DNA replication at origins. In contrast, the CDC14 protein acts after mitosis. We suggest that the CDC14 protein performs a function late in the cell cycle that may be required for efficient initiation of DNA replication during S phase of the next cell cycle.
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Affiliation(s)
- E Hogan
- Department of Embryology, Carnegie Institute of Washington, Baltimore, MD 21210
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Sethi N, Monteagudo MC, Koshland D, Hogan E, Burke DJ. The CDC20 gene product of Saccharomyces cerevisiae, a beta-transducin homolog, is required for a subset of microtubule-dependent cellular processes. Mol Cell Biol 1991; 11:5592-602. [PMID: 1922065 PMCID: PMC361930 DOI: 10.1128/mcb.11.11.5592-5602.1991] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [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: 12/29/2022] Open
Abstract
Previous analysis of cdc20 mutants of the yeast Saccharomyces cerevisiae suggests that the CDC20 gene product (Cdc20p) is required for two microtubule-dependent processes, nuclear movements prior to anaphase and chromosome separation. Here we report that cdc20 mutants are defective for a third microtubule-mediated event, nuclear fusion during mating of G1 cells, but appear normal for a fourth microtubule-dependent process, nuclear migration after DNA replication. Therefore, Cdc20p is required for a subset of microtubule-dependent processes and functions at multiple stages in the life cycle. Consistent with this interpretation, we find that cdc20 cells arrested by alpha-factor or at the restrictive temperature accumulate anomalous microtubule structures, as detected by indirect immunofluorescence. The anomalous microtubule staining patterns are due to cdc20 because intragenic revertants that revert the temperature sensitivity have normal microtubule morphologies. cdc20 mutants have a sevenfold increase in the intensity of antitubulin fluorescence in intranuclear spindles compared with spindles from wild-type cells, yet the total amount of tubulin is indistinguishable by Western immunoblot analysis. This result suggests that Cdc20p modulates microtubule structure in wild-type cells either by promoting microtubule disassembly or by altering the surface of the microtubules. Finally, we cloned and sequenced CDC20 and show that it encodes a member of a family of proteins that share homology to the beta subunit of transducin.
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Affiliation(s)
- N Sethi
- Department of Biology, University of Virginia, Charlottesville 22901
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Abstract
In the yeast, Saccharomyces cerevisiae, cell division cycle (CDC) genes have been identified whose products are required for the execution of different steps in the cell cycle. In this study, the fidelity of transmission of a 14-kb circular minichromosome and a 155-kb linear chromosome fragment was examined in cell divisions where specific CDC products were temporarily inactivated with either inhibitors, or temperature sensitive mutations in the appropriate CDC gene. All of the cdc mutants previously shown to induce loss of endogenous linear chromosomes also induced loss of a circular minichromosome and a large linear chromosome fragment in our study (either 1:0 or 2:0 loss events). Therefore, the efficient transmission of these artificial chromosomes depends upon the same trans factors that are required for the efficient transmission of endogenous chromosomes. In a subset of cdc mutants (cdc6, cdc7 and cdc16), the rate of minichromosome loss was significantly greater than the rate of loss of the linear chromosome fragment, suggesting that a structural feature of the minichromosome (nucleotide content, length or topology) makes the minichromosome hypersensitive to the level of function of these CDC gene products. In another subset of cdc mutants (cdc7 and cdc17), the relative rate of 1:0 events to 2:0 events differed for the minichromosome and chromosome fragment, suggesting that the type of chromosome loss event observed in these mutants was dependent upon chromosome structure. Finally, we show that 2:0 events for the minichromosome can occur by both a RAD52 dependent and RAD52 independent mechanism. These results are discussed in the context of the molecular functions of the CDC products.
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Affiliation(s)
- R E Palmer
- Department of Population Dynamics, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205
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Abstract
The regulation of intracellular pH (pHi) is essential for normal cell function, and controlled changes in pHi may play a central role in cell activation. Sodium-dependent Cl-HCO3 exchange is the dominant mechanism of pHi regulation in the invertebrate cells examined, and also occurs in mammalian cells. The transporter extrudes acid from the cell by exchanging extracellular Na+ and HCO3- (ref. 9) (or a related species) for intracellular Cl- (refs 3, 4). It is blocked by the stilbene derivatives DIDS (4,4'-diisothiocyano-stilbene-2,2'-disulphonate, ref. 10) and SITS (4-acetamido-4'-isothiocyano-stilbene-2,2'-disulphonate, ref. 3), and has a stoichiometry of two intracellular H+ neutralized for each Na+ taken up and each Cl- extruded by the axon. Because the inwardly-directed Na+ concentration gradient is sufficiently large to energize both the HCO3- influx and Cl- efflux, this electroneutral exchanger could be a classic secondary active transporter, thermodynamically independent of ATP hydrolysis. However, at least in the squid axon, the exchanger has an absolute requirement for ATP (ref. 3). Thus, a major unresolved issue is whether this Na-dependent Cl-HCO3 exchanger stoichiometrically hydrolyses ATP (the pump hypothesis), or whether ATP activates the transporter by a mechanism such as phosphorylation or simple binding (the activation hypothesis). We have now explored the role of ATP in pHi regulation by dialysing axons with the ATP analogue ATP-gamma-S. In many systems, ATP-gamma-S is an acceptable substrate for protein kinases, whereas the resulting thiophosphorylated proteins are not as readily hydrolysed by phosphatases as are phosphorylated proteins. Our results rule out the pump hypothesis, and show that the basis of the axon's ATP requirement is the pH-dependent activation (by, for instance, phosphorylation or ATP binding) of the exchanger itself, or of an essential activator.
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Affiliation(s)
- W F Boron
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510
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Ward S, Burke DJ, Sulston JE, Coulson AR, Albertson DG, Ammons D, Klass M, Hogan E. Genomic organization of major sperm protein genes and pseudogenes in the nematode Caenorhabditis elegans. J Mol Biol 1988; 199:1-13. [PMID: 3351915 DOI: 10.1016/0022-2836(88)90374-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [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: 01/05/2023]
Abstract
The major sperm proteins (MSPs) are a family of closely related, small, basic proteins comprising 15% of the protein in Caenorhabditis elegans sperm. They are encoded by a multigene family of more than 50 genes, including many pseudogenes. MSP gene transcription occurs only in late primary spermatocytes. In order to study the genomic organization of transcribed MSP genes, probes specific for the 3' untranslated regions of sequenced cDNA clones were used to isolate transcribed genes from genomic libraries. These and other clones of MSP genes were located in overlapping cosmid clones by DNA fingerprinting. These cosmids were aligned with the genetic map by overlap with known genes or in-situ hybridization to chromosomes. Of 40 MSP genes identified, 37, including all those known to be transcribed, are organized into six clusters composed of 3 to 13 genes each. Within each cluster, MSP genes are not in tandem but are separated by at least several thousand bases of DNA. Pseudogenes are interspersed among functional genes. Genes with similar 3' untranslated sequences are in the same cluster. The six MSP clusters are confined to only three chromosomal loci; one on the left arm of chromosome II and two near the middle of chromosome IV. Additional sperm-specific genes are located in one cluster of MSP genes on chromosome IV. The multiplicity of MSP genes appears to be a mechanism for enhancing MSP synthesis in spermatocytes, and the loose clustering of genes could be a result of the mechanism of gene duplication or could play a role in regulation.
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Affiliation(s)
- S Ward
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21210
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Abstract
1. Proton nuclear magnetic resonance spectroscopy (1H NMR) was used to measure the major intracellular metabolites in perchloric acid extracts of the Macrobdella decora muscle and nervous systems and the Oryctolagus cuniculus cerebrum. 2. Acetate, alanine, choline, glutamate, inositol, and lactate were assigned in the spectrum of leech ventral cord, leech muscle, and rabbit cerebrum. 3. Hirudonine and propionate were clearly observed only in the spectrum of leech muscle. 4. Creatine, N-acetyl aspartate, gamma aminobutyric acid, aspartate, and taurine, distinctive components of spectra of the mammalian cerebrum, were not seen in the invertebrate spectra. 5. 1H NMR spectroscopy provides a simple and rapid means of characterizing the major organic metabolites found in leech muscle and nervous tissues.
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Affiliation(s)
- O A Petroff
- Department of Neurology, Yale University, School of Medicine, New Haven, CT 06510
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Ward S, Roberts TM, Strome S, Pavalko FM, Hogan E. Monoclonal antibodies that recognize a polypeptide antigenic determinant shared by multiple Caenorhabditis elegans sperm-specific proteins. J Biophys Biochem Cytol 1986; 102:1778-86. [PMID: 2422180 PMCID: PMC2114204 DOI: 10.1083/jcb.102.5.1778] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Four monoclonal antibodies that are directed against antigens present in sperm and absent from other worm tissues were characterized. Antibody TR20 is directed against the major sperm proteins, a family of small, abundant, cytoplasmic proteins that have been previously described (Klass, M. R., and D. Hirsh, 1981, Dev. Biol., 84:299-312; Burke, D. J., and S. Ward, 1983, J. Mol. Biol., 171:1-29). Three other antibodies, SP56, SP150, and TR11, are all directed against the same set of minor sperm polypeptides that range in size from 29 to 215 kD. More than eight different sperm polypeptides are antigenic by both immunotransfer and immunoprecipitation assays. The three antibodies are different immunoglobulin subclasses, yet they compete with each other for antigen binding so they are directed against the same antigenic determinant on the multiple sperm proteins. This antigenic determinant is sensitive to any of six different proteases, is insensitive to periodate oxidation or N-glycanase digestion, and is detectable on a polypeptide synthesized in vitro. Therefore, the antigenic determinant resides in the polypeptide chain. However, peptide fragments of the proteins are not antigenic, thus the determinant is likely to be dependent on polypeptide conformation. The antigenic determinant shared by these proteins could represent a common structural feature of importance to the localization or cellular specificity of these proteins.
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Hogan E. The unique function of nursing. N Z Nurs J 1985; 78:28-9. [PMID: 3860771] [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: 01/07/2023]
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Abstract
Spermiogenesis in nematodes involves the activation of sessile spherical spermatids to motile bipolar amoeboid spermatozoa. In Caenorhabditis elegans males spermiogenesis is normally induced by copulation. Spermatids transferred to hermaphrodites as well as some of those left behind in the male become spermatozoa a few minutes after mating. Spermiogenesis can also be induced in vitro by the ionophore monensin (G.A. Nelson and S. Ward, 1980, Cell 19, 457-464) and by weak bases such as triethanolamine. Both triethanolamine and monensin cause a rapid increase in intracellular pH from 7.1 to 7.5 or 8.0. This pH increase precedes the subsequent morphological events of spermiogenesis. Triethanolamine or monensin must be present throughout spermiogenesis for all cells to form pseudopods, but once pseudopods are formed the inducers are unnecessary for subsequent motility. The pH induced spermiogenesis is inhibited by drugs that block mitochondria or glycolysis. Protease treatment can also induce spermiogenesis without increasing intracellular pH, apparently bypassing the pH-dependent steps in activation and the requirement for glycolysis. These results show that the initiation of spermiogenesis in C. elegans, like some steps in egg activation and the initiation of sea urchin sperm motility, can be induced by an increase in intracellular pH, but this pH change can be bypassed by proteolysis.
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Kirkcaldy-Hargreaves M, Casey A, Hogan E, Mulroney R. Utility of an on-line computer system in a clinical setting for nutrient intake analyses. J Can Diet Assoc 1980; 41:112-7, 122-7. [PMID: 10248685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The present report describes a four-week trial at the Victoria General Hospital, Halifax, to determine the effect of access to a computer system on nutrient intake analyses, the problems in implementation of the system, and the response of the staff dietitians. An on-line system was obtained from the Ohio State University Hospitals and modified to reflect Canadian food and nutrient content, and to include some additional program features. Twelve hundred and eighty-six foods were characterized according to 15 food components, the system was responsive to nine interactive commands, and there were nine possible print-out formats of calculations. The results of the trial reinforced the expectation of greatly increased work efficiency, however, the system was not utilized to its potential. Some technical problems were largely overcome within the first week of operation. However, needs relating to the extensiveness of the food and nutrient data base, and the methodologies and time for obtaining and evaluating individual dietary intake information prevented maximum efficiency. The dietitians liked the comprehensiveness and detail of the system, however, routine dietary intake collections were too time-consuming for their present work schedules.
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Abstract
The defect in myelinogenesis present in the Quaking mutant mouse was investigated using a double radioisotope technique for comparing the incorporation of amino acid into myelin proteins of normal and mutant mice. Quaking mice and littermate controls received intracranial injections of 150 muCi [3H]glycine and 25 muCi of [14C]glycine respectively. After 2 h their brains were combined and jointly processed to obtain subcellular fractions. The 3H/14C ratio for the myelin subfraction was 1.88 as compared to a 3H/14C ratio of 3.0 for the other subfractions, indicating a 40% decrease in glycine incorporation into myelin of Quaking mice. Myelin proteins were separated by discontinuous gel electrophoresis in the presence of sodium dodecyl sulfate (SDS) and the 3H/14C ratios determined in each gel slice. In contrast to the microsomal subfractions which gave a 3H/14C ratio of 2.6 across the gel, the 3H/14C ratio of myelin showed large variations with values ranging from 0.54 for proteolipid protein to 2.0 for some of the high molecular weight proteins. During development, the Quaking mutant exhibited a preferential depression in glycine incorporation into proteolipid protein in 18-day-old mice, while in older animals (32-54 days) the fast migrating basic protein, as well as the proteolipid protein, was labeled to a significantly lesser extent.
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