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Demidova A, Drewitz KP, Kimkool P, Banjanin N, Barzylovich V, Botjes E, Capper I, Castor MAR, Comberiati P, Cook EE, Costa J, Chu DK, Epstein MM, Galvin AD, Giovannini M, Girard F, Golding MA, Greenhawt M, Ierodiakonou D, Jones CJ, Khaleva E, Knibb RC, Macit-Çelebi MS, Mack DP, Mafra I, Marchisotto MJ, Mijakoski D, Nekliudov N, Özdemir C, Patel N, Pazukhina E, Protudjer JLP, Rodríguez Del Rio P, Roomet J, Sammut P, Schoos AMM, Schopfer AF, Schultz F, Seylanova N, Skypala I, Sørensen M, Stoleski S, Stylianou E, Upton J, van de Veen W, Genuneit J, Boyle RJ, Apfelbacher C, Munblit D. Core Outcome Set for IgE-mediated food allergy clinical trials and observational studies of interventions: International Delphi consensus study 'COMFA'. Allergy 2024; 79:977-989. [PMID: 38433402 DOI: 10.1111/all.16023] [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: 09/27/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 03/05/2024]
Abstract
BACKGROUND IgE-mediated food allergy (FA) is a global health concern with substantial individual and societal implications. While diverse intervention strategies have been researched, inconsistencies in reported outcomes limit evaluations of FA treatments. To streamline evaluations and promote consistent reporting, the Core Outcome Measures for Food Allergy (COMFA) initiative aimed to establish a Core Outcome Set (COS) for FA clinical trials and observational studies of interventions. METHODS The project involved a review of published clinical trials, trial protocols and qualitative literature. Outcomes found as a result of review were categorized and classified, informing a two-round online-modified Delphi process followed by hybrid consensus meeting to finalize the COS. RESULTS The literature review, taxonomy mapping and iterative discussions with diverse COMFA group yielded an initial list of 39 outcomes. The iterative online and in-person meetings reduced the list to 13 outcomes for voting in the formal Delphi process. One more outcome was added based on participant suggestions after the first Delphi round. A total of 778 participants from 52 countries participated, with 442 participating in both Delphi rounds. No outcome met a priori criteria for inclusion, and one was excluded as a result of the Delphi. Thirteen outcomes were brought to the hybrid consensus meeting as a result of Delphi and two outcomes, 'allergic symptoms' and 'quality of life' achieved consensus for inclusion as 'core' outcomes. CONCLUSION In addition to the mandatory reporting of adverse events for FA clinical trials or observational studies of interventions, allergic symptoms and quality of life should be measured as core outcomes. Future work by COMFA will define how best to measure these core outcomes.
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Affiliation(s)
| | - Karl Philipp Drewitz
- Institute of Social Medicine and Health Systems Research, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Parisut Kimkool
- Department of Pediatric Allergy, Imperial College Healthcare NHS Trust, London, UK
| | - Nikolina Banjanin
- Institute of Hygiene and Medical Ecology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Vladyslava Barzylovich
- Department of Pediatrics, National Medical University named after O.O. Bogomolets, Kyiv, Ukraine
| | - Erna Botjes
- Dutch Food Allergy SVA, Nijkerk, The Netherlands
| | | | - Mary Anne R Castor
- Division of Allergy and Immunology, Department of Pediatrics, College of Medicine-Philippine General Hospital, University of the Philippines Manila, Manila, Philippines
| | - Pasquale Comberiati
- Department of Clinical and Experimental Medicine, Section of Pediatrics, University of Pisa, Pisa, Italy
| | - Emma E Cook
- Modern Japanese Studies Program, Graduate School of Media and Communication, Hokkaido University, Sapporo, Japan
| | - Joana Costa
- REQUIMTE-LAQV, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Derek K Chu
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Michelle M Epstein
- Experimental Allergy Laboratory, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | | | - Mattia Giovannini
- Allergy Unit, Meyer Children's Hospital IRCCS, Florence, Italy
- Department of Health Sciences, University of Florence, Florence, Italy
| | | | - Michael A Golding
- The Children's Hospital Research Institute of Manitoba, Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Matthew Greenhawt
- Department of Pediatrics, Section of Allergy and Immunology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Despo Ierodiakonou
- Department of Primary Care and Population Health, University of Nicosia Medical School, Nicosia, Cyprus
| | | | - Ekaterina Khaleva
- Clinical and Experimental Sciences and Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Rebecca C Knibb
- School of Psychology, Aston Institute of Health and Neurodevelopment, Aston University, Birmingham, UK
| | | | - Douglas P Mack
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Isabel Mafra
- REQUIMTE-LAQV, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | | | - Dragan Mijakoski
- Department for Allergic Diseases, Institute of Occupational Health of R.N. Macedonia, WHO Collaborating Center, Skopje, North Macedonia
- Department of Occupational Medicine, Faculty of Medicine, Ss. Cyril and Methodius, University in Skopje, Skopje, North Macedonia
| | - Nikita Nekliudov
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, USA
| | - Cevdet Özdemir
- Department of Pediatric Basic Sciences, Institute of Child Health, Istanbul University, Istanbul, Turkey
| | - Nandinee Patel
- Department of Pediatric Allergy, Imperial College Healthcare NHS Trust, London, UK
| | | | - Jennifer L P Protudjer
- The Children's Hospital Research Institute of Manitoba, Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Jelena Roomet
- Centre for Allergology and Immunology, East Tallinn Central Hospital, Tallinn, Estonia
| | - Patrick Sammut
- Department of Paediatrics, Mater Dei Hospital, Msida, Malta
| | - Ann-Marie Malby Schoos
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Copenhagen University Hospital-Herlev and Gentofte, Gentofte, Denmark
- Department of Pediatrics, Slagelse Sygehus, Slagelse, Denmark
| | | | - Fallon Schultz
- International FPIES Association (IFPIES), Point Pleasant Beach, New Jersey, USA
| | | | - Isabel Skypala
- Department of Inflammation and Repair, Imperial College London, London, UK
| | - Martin Sørensen
- Regional center for asthma, allergy and hypersensitivity, University Hospital of North Norway, Tromsø, Norway
| | - Sasho Stoleski
- Department for Allergic Diseases, Institute of Occupational Health of R.N. Macedonia, WHO Collaborating Center, Skopje, North Macedonia
- Department of Occupational Medicine, Faculty of Medicine, Ss. Cyril and Methodius, University in Skopje, Skopje, North Macedonia
| | - Eva Stylianou
- Department of Pulmonary Medicine, Regional Centre for Asthma, Allergy and Hypersensitivity, Oslo University Hospital, Oslo, Norway
| | - Julia Upton
- The Hospital for Sick Children, Divison of Immunology and Allergy, Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Willem van de Veen
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland
| | - Jon Genuneit
- Pediatric Epidemiology, Department of Pediatrics, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Robert J Boyle
- Department of Pediatric Allergy, Imperial College Healthcare NHS Trust, London, UK
| | - Christian Apfelbacher
- Institute of Social Medicine and Health Systems Research, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Daniel Munblit
- Care for Long Term Conditions Division, Florence Nightingale Faculty of Nursing, Midwifery and Palliative Care, King's College London, London, UK
- Department of Paediatrics and Paediatric Infectious Diseases, Institute of Child's Health, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
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Cook EE. Anthropological and sociological perspectives on food allergy. Clin Exp Allergy 2023; 53:989-1003. [PMID: 37649424 DOI: 10.1111/cea.14387] [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: 04/02/2023] [Revised: 08/17/2023] [Accepted: 08/19/2023] [Indexed: 09/01/2023]
Abstract
This review explores the anthropological and sociological literature on food allergy and identifies four primary areas of research to date. The first explores the relationality and management of risk, uncertainty and stigma among parents and sufferers of food allergies. The second analyses the influence of intersectionality, specifically the effects of class, gender, race/ethnicity and disability on experiences of food allergy. The third discusses diagnostic difficulties and the impact these have on legitimacy and believability, both in the context of clinician-patient relations and in managing food allergies in public spaces. The fourth explores the ethics and uncertainties in food allergy treatments and how scientific knowledge of emerging treatments is constructed. This body of research illustrates that although an individual disease, food allergy experiences are significantly affected by socio-cultural structures, institutions, ideologies and discourses. The review concludes with four primary recommendations. First, there should be more incorporation of anthropological or sociological methodologies and perspectives into studies of food allergy. Second, studies are needed from more countries exploring lived experience of food allergy. Third, research on food allergy needs to incorporate an analysis of intersectional factors such as gender, class and race/ethnicity, and should explore the experiences of minority populations. Fourth, more research is needed on the interactions between biomedicine and local systems of knowledge, as well as the factors that shape what treatments become available, for whom it becomes available, experiences of treatment and aspects (including biases) that influence patient-clinician interactions.
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Affiliation(s)
- Emma E Cook
- Modern Japanese Studies, Hokkaido University, Sapporo, Japan
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Ababneh EI, Hassanein M, Saad AM, Cook EE, Ko JS, Fatica RA, Vachharajani TJ, Fernandez AP, Billings SD. Calciphylaxis in uraemic and nonuraemic settings: clinical risk factors and histopathological findings. Clin Exp Dermatol 2021; 47:700-708. [PMID: 34762763 DOI: 10.1111/ced.15009] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Calciphylaxis is a life-threatening cutaneous ulcerative/necrotic disease characterized by vascular calcification/occlusion. It occurs most commonly in end-stage kidney disease (ESKD), known as uraemic calciphylaxis (UC) but can also occur in patients with chronic kidney disease (CKD) and normal kidney function (nonuraemic calciphylaxis; NUC). There are few large series of NUC in the literature. AIM To compare the clinicopathological features of UC and NUC. METHODS We retrospectively compared the clinicopathological features of 35 patients with NUC during the period 2010-2020 with those of 53 patients with UC (control group). Cases were classified as NUC in the absence of all of the following: ESKD, significant CKD (defined as serum creatinine > 3 mg/dL or creatinine clearance < 15 mL/min) and acute kidney injury requiring kidney replacement therapy or kidney transplantation. RESULTS NUC represented 40% of the total cases, and there was a higher number of women (P < 0.01) and a higher median body mass index (P = 0.06) compared with the control UC group. Elevated parathyroid hormone was present in 44% of patients with NUC. Most of the tested patients were positive for lupus anticoagulants (56%). NUC biopsies showed a higher rate of extravascular calcium deposits (73% vs. 47%, P = 0.03). Dermal reactive vascular proliferation was the most common dermal change (32%). CONCLUSIONS NUC is more common than previously reported and shows a higher predilection for obese postmenopausal women. Undiagnosed hyperparathyroidism shows a possible association with NUC. Lupus anticoagulants were positive in most patients. NUC biopsies are more likely than UC biopsies to display extravascular calcium deposition.
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Affiliation(s)
- E I Ababneh
- Department of, Pathology, Cleveland Clinic, Cleveland, OH, USA
| | - M Hassanein
- Department of, Nephrology and Hypertension, Cleveland Clinic, Cleveland, OH, USA.,Department of, Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - A M Saad
- Department of, Dermatology, Cleveland Clinic, Cleveland, OH, USA.,Department of Nephrology and Hypertension, University of Mississippi Medical Center, Mississippi, MO, USA
| | - E E Cook
- Department of, Pathology, Cleveland Clinic, Cleveland, OH, USA
| | - J S Ko
- Department of, Pathology, Cleveland Clinic, Cleveland, OH, USA
| | - R A Fatica
- Department of, Nephrology and Hypertension, Cleveland Clinic, Cleveland, OH, USA
| | - T J Vachharajani
- Department of, Nephrology and Hypertension, Cleveland Clinic, Cleveland, OH, USA
| | - A P Fernandez
- Department of Pathology, Detroit Medical Center, Detroit, MI, USA
| | - S D Billings
- Department of, Pathology, Cleveland Clinic, Cleveland, OH, USA
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Cook EE. Galbraith, Patrick W. Otaku and the struggle for imagination in Japan. x, 325 pp., illus., bibliogr. Durham, N.C.: Duke Univ. Press, 2019. £22.99 (paper). J R Anthropol Inst 2021. [DOI: 10.1111/1467-9655.13531] [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: 11/29/2022]
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Cook EE. Laszczkowski, Mateusz & MadeleineReeves (eds). Affective states: entanglements, suspensions, suspicions. x, 148 pp., bibliogrs. Oxford, New York: Berghahn Books, 2018. £22.95 (paper). J R Anthropol Inst 2021. [DOI: 10.1111/1467-9655.13455] [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: 11/29/2022]
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Abstract
"Food is relationships isn't it," Yamada san stated in 2017, neatly capturing the importance of food in social life. This article, drawing on the experiences of people with severe food allergies in Japan, illustrates the complexities of safely managing allergies when food-and the importance of sharing the same food-is so important to social life. In particular, I argue that individuals develop and practice skills of vigilance and situational awareness to mitigate physical and social risk which emerge through an affective imagination of what they feel could happen in the future, built on embodied memories of what has been experienced prior (e.g., severe allergic reactions and difficult social experiences with food). The development and enactment of these skills of vigilance happen through an 'education of attention' (Gibson in The ecological approach to visual perception, Psychology Press, New York, 1979; Ingold in The perception of the environment: essays on livelihood, dwelling and skill, Routledge, London, 2000) developed over time and in different social settings and constitute a somatic mode of attention (Csordas in Cult Anthropol 8:135-156, 1993) which shapes social interactions and aims to mitigate against any potential perceived social costs for not being able to eat everything.
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Affiliation(s)
- Emma E. Cook
- Modern Japanese Studies Program, Hokkaido University, Kita 15, Nishi 8, Kita Ku, Sapporo, 060-0815 Japan
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Cook EE. Takeyama, Akiko. Staged seduction: selling dreams in a Tokyo host club. xviii, 225 pp., illus., bibliogr. Stanford: Univ. Press, 2016. £16.99 (paper). J R Anthropol Inst 2018. [DOI: 10.1111/1467-9655.12772] [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: 11/30/2022]
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Cook EE. Working Skin: Making Leather, Making a Multicultural Japan by Joseph D. Hankins. Berkeley: University of California Press, 2014. 304 pp. American Anthropologist 2016. [DOI: 10.1111/aman.12468] [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: 11/26/2022]
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Wolfson SK, Safar P, Reich H, Clark JM, Gur D, Stezoski W, Cook EE, Krupper MA. Dynamic heterogeneity of cerebral hypoperfusion after prolonged cardiac arrest in dogs measured by the stable xenon/CT technique: a preliminary study. Resuscitation 1992; 23:1-20. [PMID: 1315066 DOI: 10.1016/0300-9572(92)90158-9] [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: 12/26/2022]
Abstract
After prolonged cardiac arrest and reperfusion, global cerebral blood flow (gCBF) is decreased to about 50% normal for many hours. Measurement of gCBF does not reveal regional variation of flow or permit testing of hypotheses involving multifocal no-flow or low-flow areas. We employed the noninvasive stable Xenon-enhanced Computerized Tomography (Xe/CT) local CBF (LCBF) method for use in dogs before and after ventricular fibrillation (VF) cardiac arrest of 10 min. This was followed by external cardiopulmonary resuscitation (CPR) and control of cardiovascular pulmonary variables to 7 h postarrest. In a sham (no arrest) experiment, the three CT levels studied showed normal regional heterogeneity of LCBF values, all between 10 and 75 ml/100 cm3 per min for white matter and 20 and 130 ml/100 cm3 per min for gray matter. In four preliminary CPR experiments, the expected global hyperemia at 15 min after arrest, was followed by hypoperfusion with gCBF reduced to about 50% control and increased heterogeneity of LCBF. Trickle flow areas (LCBF less than 10 ml/100 cm3 per min) not present prearrest, were interspersed among regions of low, normal, or even high flow. Regions of 125-500 mm3 with trickle flow or higher flows, in different areas at different times, involving deep and superficial structures migrated and persisted to 6 h, with gCBF remaining low. These preliminary results suggest: no initial no-reflow foci (less than 10 ml/100 cm3 per min) larger than 125 mm3 persisting through the initial global hyperemic phase; delayed multifocal hypoperfusion more severe than suggested by gCBF measurements; and trickle flow areas caused by dynamic factors.
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Affiliation(s)
- S K Wolfson
- Department of Neurological Surgery, International Resuscitation Research Center, Pittsburgh, PA
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Wolfson SK, Clark J, Greenberg JH, Gur D, Yonas H, Brenner RP, Cook EE, Lordeon PA. Xenon-enhanced computed tomography compared with [14C]iodoantipyrine for normal and low cerebral blood flow states in baboons. Stroke 1990; 21:751-7. [PMID: 2339455 DOI: 10.1161/01.str.21.5.751] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [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: 12/31/2022]
Abstract
The correlation between the acute, invasive diffusible [14C]iodoantipyrine technique for cerebral blood flow and the noninvasive xenon-enhanced computed tomographic method has been assessed by simultaneous measurements in the baboon. Blood flows in small tissue volumes (about 0.125 cm3) were directly compared in normal and low flow states. These studies demonstrate a statistically significant association between the two methods (p less than 0.001). Similar correlations were obtained by both the Kendall (tau) and the Spearman (r) methods (r = 0.67 to 0.92, n greater than or equal to 19 for each study). The problems and limitations of such correlations are discussed.
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Affiliation(s)
- S K Wolfson
- Department of Neurological Surgery, University of Pittsburgh, Pennsylvania
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Wolfson SK, Yonas H, Gur D, Cook EE, Greenberg J, Brenner RP. Autoregulation remains intact during stable xenon inhalation in the baboon. Adv Exp Med Biol 1990; 277:865-72. [PMID: 2096687 DOI: 10.1007/978-1-4684-8181-5_99] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To test the possible effect of 32% end-tidal Xe concentration upon autoregulation, 5 baboons, Papio anubis/cynocephalus, were anesthetized/paralyzed with propranolol 0.02, diazepam 0.1, morphine sulfate 0.1, and pancuronium 0.2 (mg/(h.kg)). The animals were subjected to a servocontrolled blood infusion-withdrawal program to control central aortic blood pressure (CAP). PaCO2 was held to 30 to 35 torr, with individual variation less than 3 torr by control of ventilation and by including CO2 in the Xe/O2 mixture. Three to six CBF measurements were made in each subject over the above range. In four animals the CAP was varied between 18 and 150 torr, with corresponding CBF measurements. The CAP range was extended to 196 torr in the 5th animal by IV administration of phenylephrine. Significant lowering of global blood flow did not occur above 40 torr mean CAP. While regulated flow persists to about 150 torr at the high end, there is a breakaway between 150 and 190 torr where flow increased 90%. A 4th order polynomial fit of the data has the characteristic appearance of the familiar autoregulation curve. We conclude that autoregulation is preserved even in the presence of FIXe of 32% in the breathing mixture.
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Affiliation(s)
- S K Wolfson
- Montefiore Hospital, Department of Neurological Surgery, University of Pittsburgh, PA
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Dujovny M, Kossovsky N, Kossowsky R, Segal R, Diaz FG, Kaufman H, Perlin A, Cook EE. Mechanical and metallurgical properties of carotid artery clamps. Neurosurgery 1985; 17:760-7. [PMID: 4069328 DOI: 10.1227/00006123-198511000-00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.
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Gur D, Yonas H, Jackson DL, Wolfson SK, Rockette H, Good WF, Cook EE, Arena VC, Willy JA, Maitz GS. Simultaneous measurements of cerebral blood flow by the xenon/CT method and the microsphere method. A comparison. Invest Radiol 1985; 20:672-7. [PMID: 4066237 DOI: 10.1097/00004424-198510000-00004] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Simultaneous measurements of cerebral blood flow have been performed in baboons to assess the correlation between the acute and invasive nondiffusible microsphere technique and the noninvasive xenon-enhanced CT method. Blood flows in small tissue volumes (approximately 1 cm3) were directly compared. The results of these studies demonstrate a statistically significant association between the two methods (P less than .001). Similar correlations were obtained by both the Kendall tau (tau) and the Spearman (r) methods. The problems and limitations of such correlations are discussed.
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Gur D, Yonas H, Jackson DL, Wolfson SK, Rockette H, Good WF, Maitz GS, Cook EE, Arena VC. Measurement of cerebral blood flow during xenon inhalation as measured by the microspheres method. Stroke 1985; 16:871-4. [PMID: 4049451 DOI: 10.1161/01.str.16.5.871] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Measurements of cerebral blood flow (CBF) were performed using the microsphere technique in non-human primates (baboons) to assess the effect of non-radioactive xenon gas inhalation on CBF. Blood flows in small tissue volumes (approximately 1 cm3) were directly measured before and during the inhalation of xenon/oxygen gas mixtures. The results of these studies demonstrated that when inhaled in relatively high concentrations, xenon gas does increase CBF, but the changes are more global than tissue-specific. The problems and limitations of such evaluations are discussed.
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Jannetta PJ, Segal R, Wolfson SK, Dujovny M, Semba A, Cook EE. Neurogenic hypertension: etiology and surgical treatment. II. Observations in an experimental nonhuman primate model. Ann Surg 1985; 202:253-61. [PMID: 4015232 PMCID: PMC1250882 DOI: 10.1097/00000658-198508000-00018] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In a companion paper (Ann Surg 1985; 201(3):391-398), clinical data which suggest that neurogenic hypertension may be caused by arterial compression of the left medulla oblongata was presented. A chronic pathophysiologic animal model of neurogenic hypertension using a substitute for arterial pulsation, the neurovascular compression simulator (NCS), was developed. This paper presents data that demonstrate how development of hypertension in a nonhuman primate baboon (5 subject animals, 5 control animals) can be caused by the NCS, and the blood pressure can subsequently return to normal following cessation of NCS activity. These experiments show that pulsatile compression of the left ventrolateral medulla oblongata results in cardiovascular changes consistent with the sequence found in human neurogenic hypertension. Arteriosclerosis and arterial ectasia in the human contribute to arterial elongation and looping at the base of the brain. An arterial loop, by causing pulsatile compression of neural structures, elicits an increase in blood pressure initiated by an increase in cardiac output. This may be due to interference with the autonomic control of the heart and/or by alteration of the relative capacitance of the vascular system.
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Gur D, Yonas H, Wolfson SK, Wozney P, Colsher JG, Good WF, Good BC, Herbert DL, Cook EE. Xenon/CT blood flow mapping of the kidney and liver. J Comput Assist Tomogr 1984; 8:1124-7. [PMID: 6501620 DOI: 10.1097/00004728-198412000-00015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A noninvasive technique for measuring blood flow by xenon-enhanced X-ray transmission CT has been developed and reported quite extensively in recent years. In this method nonradioactive xenon gas is inhaled, and the temporal changes in radiographic enhancement produced by the inhalation are measured by sequential CT. Time-dependent xenon concentration within various tissue segments is used to derive local blood flow maps. The method has been amply discussed in relation to assessment of local cerebral blood flow. Its application to other body organs is explored in this paper, in which results from six preliminary blood flow studies in the liver and kidneys of nonhuman primates are reported. Blood flow in renal cortex ranged from 150 to 280 ml/100 cc/min and hepatic tissue perfusion from 80 to 120 ml/100 cc/min. The advantages and limitations of the method in such applications are discussed.
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Abstract
A number of investigations utilizing hypothalami from adrenalectomized animals have provided conflicting results regarding the role of serotonin (5HT) and norepinephrine (NE) in CRF regulation. In order to further investigate these neurotransmitters, we performed three sets of experiments with hypothalami obtained from intact rats. In experiment I, freshly obtained rat hypothalami were randomly grouped and incubated in control medium and medium in the presence of 10(-11) M, 10(-10) M, and 10(-9) M serotonin. Aliquots of 200 microliters of these incubates were bioassayed for CRF activity using a dispersed anterior pituitary cell system, and ACTH secretion from the cells was determined by radioimmunoassay. A preliminary experiment had determined that a 200 microliters aliquot from hypothalami incubated in control medium resulted in a significantly (p less than 0.0001) greater ACTH release than obtained from cells alone. No significant effect of serotonin on hypothalamic CRF release was obtained. In experiment III, individual hypothalami were bisected longitudinally, and one half served as control. The contralateral half was incubated in medium containing 10(-11) M, 10(-10) M, and 10(-9) M serotonin. CRF release in this experiment again revealed no significant effect of serotonin. In experiment II, hypothalami were again randomly grouped and incubated with control medium and in the presence of 10(-8) M and 10(-6) M norepinephrine. This experiment resulted in no significant effect of norepinephrine on CRF release. These results suggest that serotonin and norepinephrine at the concentrations studied have no effect on CRF release from hypothalami obtained from intact rats.
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18
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Gur D, Wolfson SK, Yonas H, Good WF, Shabason L, Latchaw RE, Miller DM, Cook EE. Progress in cerebrovascular disease: local cerebral blood flow by xenon enhanced CT. Stroke 1982; 13:750-8. [PMID: 6755813 DOI: 10.1161/01.str.13.6.750] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A noninvasive technique for measuring local cerebral blood flow (LCBF) by xenon enhanced x-ray transmission computed tomography (CT) has been developed an reported quite extensively in recent years. In this method, nonradioactive xenon gas in inhaled and the temporal changes in radiographic enhancement produced by the inhalation are measured by sequential computed tomography. Time dependent xenon concentrations within various tissue segments in the brain are used to derive both local partition coefficient (lambda) and LCBF. An assessment of this method reveals that although it provides functional mapping of blood flow with excellent anatomic specificity, there are distinct limitations. The assumptions underlying this methodology are examined and problems associated with various potential applications of this technique are discussed.
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19
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Segal R, Jannetta PJ, Wolfson SK, Dujovny M, Cook EE. Implanted pulsatile balloon device for simulation of neurovascular compression syndromes in animals. J Neurosurg 1982; 57:646-50. [PMID: 7131065 DOI: 10.3171/jns.1982.57.5.0646] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A self-contained neurovascular compression simulator (NCS) has been designed to function as an artificial artery that pulsates with the heart. When implanted in animals, this device simulates those naturally occurring situations in which there is compression of nervous elements in the region of the brain stem or other areas by aberrant, or ectatic branches of normal arteries. The NCS consists of an intra-aortic balloon, a smaller (cephalic) balloon, a connecting tube, and an injection port, all fabricated of polyurethane-silicone compounds. With each heart systole, the rise in intra-aortic pressure is transmitted to the smaller cephalic balloon in the form of a pulsation. Thus, part of the cardiac ejection energy is transferred to the desired nervous structures. The performance of each NCS is tested in vitro in a pulse duplicator system. The NCS was chronically implanted for up to 2 years in four dogs and 10 baboons. The cephalic balloon was placed intracranially in the subarachnoid space on the ventrolateral medulla adjacent to the entry zone of the ninth and 10th cranial nerves on the left side of baboons and on the right side of dogs. The position of the balloons was checked by fluoroscopy. Following implantation, the NCS could be inflated or deflated at will using the injection port which served to restart or discontinue the pulsations. No occlusion of the aorta or reduction of blood flow to the lower limbs or trunk was detected. By means of the NCS, an experimental model of neurogenic hypertension was produced in baboons.
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20
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Gambert SR, Garthwaite TL, Pontzer CH, Cook EE, Tristani FE, Duthie EH, Martinson DR, Hagen TC, McCarty DJ. Running elevates plasma beta-endorphin immunoreactivity and ACTH in untrained human subjects. Proc Soc Exp Biol Med 1981; 168:1-4. [PMID: 6275394 DOI: 10.3181/00379727-168-41225] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Twenty minutes of submaximal treadmill running was associated with an elevation in plasma levels of beta-endorphin immunoreactivity (P less than 0.02). This increase was greater in men (14.9 +/- 3.4 fmole/ml) than women (2.6 +/- 1.2 fmole/ml)(P less than 0.05). Plasma levels of ACTH and growth hormone also increased after running. ACTH increased more in men (7.8 +/- 1.1 fmole/ml) than in women (1.1 +/-0.44 fmole/ml)(P less than 0.02). There was a similar growth hormone response in both sexes. No correlation can at this time be made with levels in the central nervous system. Changes in plasma levels of beta-endorphin immunoreactivity may be responsible for some of the euphoria and analgesia anecdotally associated with running.
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21
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Abstract
Short- and long-term side effects during and after inhalation of premixed xenon oxygen (28-47%) from 12 studies are reported. While all but one subject tolerated xenon inhalation without ill effects, that individual did experience unpleasantly severe dysesthesias and a brief period of unresponsiveness. We believe that further human studies with xenon inhalation should be conducted to explore possible early indicators for reduced tolerance of xenon by certain individuals.
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Drayer BP, Gur D, Yonas H, Wolfson SK, Cook EE. Abnormality of the xenon brain:blood partition coefficient and blood flow in cerebral infarction: an in vivo assessment using transmission computed tomography. Radiology 1980; 135:349-54. [PMID: 6768103 DOI: 10.1148/radiology.135.2.6768103] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Xenon-enhanced computed tomography (CT) was used to analyze, in vivo, the patterns of blood flow of cerebral infarction in a nonhuman primate model. Consistent and reproducible results were attained utilizing the numerical data from CT scans obtained during the inhalation of nonradioactive xenon. The spatial resolution of CT defined a morphophysiologic map of the variability in brain:blood partition coefficient and flow rate constant that exist within and around an infarct. Both the flow and the partition coefficient were significantly diminished in the ischemic focus in all animals studied. Although the partition coefficients were normal, the flow was decreased in the other locales sampled in the ipsilateral hemispheres. In the contralateral hemispheres, both flows and partition coefficients were within the range of normal for adolescent baboons.
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23
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Abstract
Xenon-enhanceed cranial computed tomography (CT) was used to derive the partition coefficient (lambda) and flow rate constant (kappa) and thus provide a functional neuroanatomic map of local cerebral blood flow in eight nonhuman primates. Sequential CT imaging defined the temporal changes of xenon concentration in arterial blood and brain tissue both during and after xenon inhalation. Several methodologies including clearance, buildup, and in vivo "autoradiography" were used to estimate flow in various brain locales. A typical derived fast flow rate using xenon CT methodology was 85 ml/100 g/min, with a range of 58--108. The in vivo autoradiographic method of defining flow seems more clinically applicable in man. The limitations and potential solutions using CT blood flow techniques are discussed.
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Drayer BP, Dujovny M, Wolfson SK, Boehnke M, Cook EE, Rosenbaum AE. Comparative cranial CT enhancement in a primate model of cerebral infarction. Ann Neurol 1979; 5:48-58. [PMID: 581830 DOI: 10.1002/ana.410050108] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The value of various enhancement techniques as opposed to nonenhanced CT scanning was compared in 15 baboons with cerebral infarction secondary to embolization of the left middle cerebral artery. The most prominent CT findings in infarction included an area of low absorption in the opercula--basal ganglia--centrum semiovale region and generalized lateral ventricular enlargement. Intravenous enhancement of the low-density region occurred in 25% of the animals and often obscured the preenhancement abnormality. However, a rapid bolus injection of contrast material followed by immediate consecutive CT scans (computed angiotomography) permitted prominent visualization of early-shunting veins. Delayed scanning following intrathecal enhancement better defined small infarctions that did not exhibit the usual cerebral blush. The CT imaging of inhaled xenon provides a new technique for evaluating subtle abnormalities in cerebral perfusion, even when the routine CT scan shows no abnormality.
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25
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Abstract
The application of intravenous, intrathecal, and inhalation enhancement techniques to the CT evaluation of the nonhuman primate (Papio cynocephalus/anubis) is described. The falx cerebri cortical vasculature, vein of Galen, straight sinus and tentorium cerebelli were defined with intravenous enhancement. Intrathecal CT enhancement with air was limited by distortion in cerebrospinal fluid spaces. Intrathecal CT enhancement using a low dose of metrizamide accurately delineated the subarachnoid spaces and the brain substance they surrounded with minimal morbidity. Symmetrical brain enhancement (perfusion) was prominent following inhalation CT enhancement; the degree of enhancement correlated with the estimated xenon concentration in the bloodstream. In addition, by performing repeated CT scans during the clearance of xenon from the brain, an approximate analysis of regional cerebral blood flow was obtained.
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26
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Drayer BP, Wolfson SK, Reinmuth OM, Dujovny M, Boehnke M, Cook EE. Xenon enhanced CT for analysis of cerebral integrity, perfusion, and blood flow. Stroke 1978; 9:123-30. [PMID: 417427 DOI: 10.1161/01.str.9.2.123] [Citation(s) in RCA: 116] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Enhancement of the brain substance for CT evaluation using inhaled Xenon is confirmed. This technique was applied to the study of the normal and the embolized adolescent baboon. Healthy cerebral tissue enhances symmetrically, while abnormal areas show significantly diminished enhancement. At maximal enhancement, an indication of gross comparative cerebral perfusion to obtained. By obtaining serial CT scans over a 10 minute time interval, the clearance rate of Xenon (cerebral blood flow) may be evaluated. Xenon-enhanced CT enables a visual and numerical analysis of both brain morphology and physiology.
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27
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Drayer BP, Wolfson SK, Boehnke M, Dujovny M, Rosenbaum AE, Cook EE. Physiologic changes in regional cerebral blood flow defined by xenon-enhanced CT scanning. Neuroradiology 1978; 16:220-3. [PMID: 105309 DOI: 10.1007/bf00395255] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With adequate concentrations of commercially available nonradioactive xenon an enhancement of brain substance was readily demonstrated by computed tomography (CT). By performing successive CT scans at a fixed brain level following xenon inhalation, the partition coefficient and clearance of xenon as well as the regional cerebral blood flow (rCBF) could be calculated. The expected physiologic alterations in rCBF with acute cerebral infarction and changes in arterial CO2 were accurately defined by xenon-enhanced CT scanning affirming the potential future applications of this technique.
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28
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Abstract
A simple, reliable, reproducible technique for performing CT scans on baboons is described. The normal morphologic appearance in 12 nonhuman primate (Papio cynocephalusl anubis) brains as defined by CT is correlated with the normal gross pathologic findings on postmortem examination. The orbital contents are also displayed with clarity equivalent to that obtained in man.
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29
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Drayer BP, Dujovny M, Boehnke M, Wolfson SK, Barrionuevo PJ, Cook EE, Rosenbaum AE. The capacity for computed tomography diagnosis of cerebral infarction. An experimental study in the nonhuman primate. Radiology 1977; 125:393-402. [PMID: 410069 DOI: 10.1148/125.2.393] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The characteristic serial CT scan appearance of cerebral infarction created by embolization of the middle cerebral artery in the nonhuman primate (10 baboons) is defined. The earliest CT changes are noted by 12 to 24 hours and include generalized ventricular enlargement and a focal region of decreased absorption in the opercula-basal ganglia region. The area of diminished brain absorption is better circumscribed and of lower attenuation coefficient with increasing chronicity. Distinct hydrocephalus, unilateral exophthalmos and ventricular displacement occurred with increased intracranial pressure. Little additional diagnostic information was obtained via intravenous enhancement and care should be taken as mild enhancement may obscure an area of abnormality.
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30
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Drayer BP, Dujovny M, Wolfson SK, Boehnke M, Cook EE, Barrionuevo PJ. Ophthalmologic applications of computed tomography in nonhuman primates. J Comput Assist Tomogr 1977; 1:324-9. [PMID: 97334 DOI: 10.1097/00004728-197707000-00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The orbital contents of 28 baboons are defined by computed tomography (CT), which provides a simple, reliable, reproducible, and accurate technique for the experimental investigation of the orbit of the nonhuman primate. This method is applied to the diagnosis of exophthalmos. The suprasellar and other basal subarachnoid cisterns are precisely delineated using intrathecal enhancement prior to CT imaging (metrizamide CT cisternography).
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