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Hyman S, Zhang J, Andersen ZJ, Cruickshank S, Møller P, Daras K, Williams R, Topping D, Lim YH. Long-term exposure to air pollution and COVID-19 severity: A cohort study in Greater Manchester, United Kingdom. Environ Pollut 2023; 327:121594. [PMID: 37030601 PMCID: PMC10079212 DOI: 10.1016/j.envpol.2023.121594] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 05/19/2023]
Abstract
Exposure to outdoor air pollution may affect incidence and severity of coronavirus disease 2019 (COVID-19). In this retrospective cohort based on patient records from the Greater Manchester Care Records, all first COVID-19 cases diagnosed between March 1, 2020 and May 31, 2022 were followed until COVID-19 related hospitalization or death within 28 days. Long-term exposure was estimated using mean annual concentrations of particulate matter with diameter ≤2.5 μm (PM2.5), ≤10 μm (PM10), nitrogen dioxide (NO2), ozone (O3), sulphur dioxide (SO2) and benzene (C6H6) in 2019 using a validated air pollution model developed by the Department for Environment, Food and Rural Affairs (DEFRA). The association of long-term exposure to air pollution with COVID-19 hospitalization and mortality were estimated using multivariate logistic regression models after adjusting for potential individual, temporal and spatial confounders. Significant positive associations were observed between PM2.5, PM10, NO2, SO2, benzene and COVID-19 hospital admissions with odds ratios (95% Confidence Intervals [CI]) of 1.27 (1.25-1.30), 1.15 (1.13-1.17), 1.12 (1.10-1.14), 1.16 (1.14-1.18), and 1.39 (1.36-1.42), (per interquartile range [IQR]), respectively. Significant positive associations were also observed between PM2.5, PM10, SO2, or benzene and COVID-19 mortality with odds ratios (95% CI) of 1.39 (1.31-1.48), 1.23 (1.17-1.30), 1.18 (1.12-1.24), and 1.62 (1.52-1.72), per IQR, respectively. Individuals who were older, overweight or obese, current smokers, or had underlying comorbidities showed greater associations between all pollutants of interest and hospital admission, compared to the corresponding groups. Long-term exposure to air pollution is associated with developing severe COVID-19 after a positive SARS-CoV-2 infection, resulting in hospitalization or death.
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Affiliation(s)
- Samuel Hyman
- Department of Earth and Environmental Science, Centre for Atmospheric Science, School of Natural Sciences, The University of Manchester, Manchester, UK; Institute of Immunology and Inflammation, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, UK.
| | - Jiawei Zhang
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Zorana Jovanovic Andersen
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Sheena Cruickshank
- Institute of Immunology and Inflammation, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, UK
| | - Peter Møller
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Konstantinos Daras
- Department of Public Health, Policy and Systems, Institute of Population Health, University of Liverpool, Liverpool, UK
| | - Richard Williams
- Division of Informatics, Imaging and Data Science, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; NIHR Greater Manchester Patient Safety Translational Research Centre, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK; NIHR Applied Research Collaboration Greater Manchester, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - David Topping
- Department of Earth and Environmental Science, Centre for Atmospheric Science, School of Natural Sciences, The University of Manchester, Manchester, UK
| | - Youn-Hee Lim
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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Gottschlich M, Hyman S, Pisner D, Singh A, Millan M, Knight S, Grandner MA, Killgore WD. 1169 POST-CONCUSSION SEVERITY IS ASSOCIATED WITH SLEEP PROBLEMS AND NEUROPSYCHOLOGICAL STATUS. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.1168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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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Wang L, Wu Y, Perez KC, Hyman S, Brunski JB, Tulu U, Bao C, Salmon B, Helms JA. Effects of Condensation on Peri-implant Bone Density and Remodeling. J Dent Res 2017; 96:413-420. [PMID: 28048963 DOI: 10.1177/0022034516683932] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Bone condensation is thought to densify interfacial bone and thus improve implant primary stability, but scant data substantiate either claim. We developed a murine oral implant model to test these hypotheses. Osteotomies were created in healed maxillary extraction sites 1) by drilling or 2) by drilling followed by stepwise condensation with tapered osteotomes. Condensation increased interfacial bone density, as measured by a significant change in bone volume/total volume and trabecular spacing, but it simultaneously damaged the bone. On postimplant day 1, the condensed bone interface exhibited microfractures and osteoclast activity. Finite element modeling, mechanical testing, and immunohistochemical analyses at multiple time points throughout the osseointegration period demonstrated that condensation caused very high interfacial strains, marginal bone resorption, and no improvement in implant stability. Collectively, these multiscale analyses demonstrate that condensation does not positively contribute to implant stability.
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Affiliation(s)
- L Wang
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Y Wu
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA.,3 Orthodontic Department, Stomatology Hospital of Chongqing Medical University; Chongqing Key Laboratory of Oral Disease and Biomedical Sciences; Chongqing Municipal Key Laboratory, Chongqing, China
| | - K C Perez
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - S Hyman
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - J B Brunski
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - U Tulu
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - C Bao
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - B Salmon
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA.,4 EA 2496, Orofacial Pathologies, Imaging and Biotherapies Laboratory, Paris Descartes University-Sorbonne Paris Cité, Montrouge, France; and AP-HP Odontology Department Bretonneau, Hopitaux Universitaires Paris Nord Val de Seine, Paris, France
| | - J A Helms
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
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Ransom RC, Hunter DJ, Hyman S, Singh G, Ransom SC, Shen EZ, Perez KC, Gillette M, Li J, Liu B, Brunski JB, Helms JA. Axin2-expressing cells execute regeneration after skeletal injury. Sci Rep 2016; 6:36524. [PMID: 27853243 PMCID: PMC5113299 DOI: 10.1038/srep36524] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 10/18/2016] [Indexed: 01/20/2023] Open
Abstract
The mammalian skeleton performs a diverse range of vital functions, requiring mechanisms of regeneration that restore functional skeletal cell populations after injury. We hypothesized that the Wnt pathway specifies distinct functional subsets of skeletal cell types, and that lineage tracing of Wnt-responding cells (WRCs) using the Axin2 gene in mice identifies a population of long-lived skeletal cells on the periosteum of long bone. Ablation of these WRCs disrupts healing after injury, and three-dimensional finite element modeling of the regenerate delineates their essential role in functional bone regeneration. These progenitor cells in the periosteum are activated upon injury and give rise to both cartilage and bone. Indeed, our findings suggest that WRCs may serve as a therapeutic target in the setting of impaired skeletal regeneration.
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Affiliation(s)
- R C Ransom
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA.,Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - D J Hunter
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - S Hyman
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - G Singh
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - S C Ransom
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - E Z Shen
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - K C Perez
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - M Gillette
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - J Li
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - B Liu
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - J B Brunski
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
| | - J A Helms
- Hagey Laboratory for Pediatric Regenerative Medicine, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305-5148, USA
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Kirmse R, Hyman S, Alvarez-Jimenez A. C-37Intensity and Frequency of Yoga Practice Associated with Enhanced Cognitive Flexibility in Healthy Adults. Arch Clin Neuropsychol 2016. [DOI: 10.1093/arclin/acw043.186] [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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Huang L, Liu B, Cha J, Yuan G, Kelly M, Singh G, Hyman S, Brunski J, Li J, Helms J. Mechanoresponsive Properties of the Periodontal Ligament. J Dent Res 2016; 95:467-75. [PMID: 26767771 DOI: 10.1177/0022034515626102] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The periodontal ligament (PDL) functions as an enthesis, a connective tissue attachment that dissipates strains created by mechanical loading. Entheses are mechanoresponsive structures that rapidly adapt to changes in their mechanical loading; here we asked which features of the PDL are sensitive to such in vivo loading. We evaluated the PDL in 4 physiologically relevant mechanical environments, focusing on mitotic activity, cell density, collagen content, osteogenic protein expression, and organization of the tissue. In addition to examining PDLs that supported teeth under masticatory loading and eruptive forces, 2 additional mechanical conditions were created and analyzed: hypoloading and experimental tooth movement. Collectively, these data revealed that the adult PDL is a remarkably quiescent tissue and that only when it is subjected to increased loads—such as those associated with mastication, eruption, and orthodontic tooth movement—does the tissue increase its rate of cell proliferation and collagen production. These data have relevance in clinical scenarios where PDL acclimatization can be exploited to optimize tooth movement.
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Affiliation(s)
- L. Huang
- Orthodontic Department, Stomatology Hospital of Chongqing Medical University; Chongqing Key Laboratory of Oral Disease and Biomedical Sciences; Chongqing Municipal Key Laboratory, Chongqing, China
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - B. Liu
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - J.Y. Cha
- Department of Orthodontics, College of Dentistry, Yonsei University, Seoul, South Korea
| | - G. Yuan
- Department of Orthodontics, Dalian Stomatological Hospital, Dalian Medical University, Dalian, China
| | - M. Kelly
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - G. Singh
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - S. Hyman
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - J.B. Brunski
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - J. Li
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
- Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - J.A. Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
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Hyman S, Stanner S. Dispelling popular myths that discourage breastfeeding. NUTR BULL 2004. [DOI: 10.1111/j.1467-3010.2004.00433.x] [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: 11/27/2022]
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Hyman S, Rawson NE. Preliminary results of olfactory testing in rats without deprivation. Lab Anim (NY) 2001; 30:38-9. [PMID: 11385725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Although rodents are nocturnal, their behavior is usually tested during the day. The authors present the results of a preliminary study, which suggest that altering the animals' day:night cycle might be the key to eliminating the need for food or water deprivation prior to testing.
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Affiliation(s)
- S Hyman
- Monell Chemical Senses Center, 3500 Market St., Philadelphia, PA 19104, USA
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9
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Affiliation(s)
- S Hyman
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA.
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10
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Kogai T, Curcio F, Hyman S, Cornford EM, Brent GA, Hershman JM. Induction of follicle formation in long-term cultured normal human thyroid cells treated with thyrotropin stimulates iodide uptake but not sodium/iodide symporter messenger RNA and protein expression. J Endocrinol 2000; 167:125-35. [PMID: 11018760 DOI: 10.1677/joe.0.1670125] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Iodide uptake by the sodium/iodide symporter (NIS) in thyrocytes is essential for thyroid hormone production. Reduced NIS activity has been reported in thyroid diseases, including thyroid cancer and congenital hypothyroidism. The study of iodide uptake in thyrocytes has been limited by the availability of appropriate in vitro models. A new culture technique was recently developed that allows normal human thyroid primary culture cells to grow as monolayer cells and express differentiated functions for more than 3 months. We used this technique to study the effect of follicle formation and TSH on iodide uptake in these cells. Iodide uptake by the cells grown in monolayer was very low. Follicle formation was induced from monolayer cells, and electron micrographs demonstrated cell polarity in the follicles. No significant increase in iodide uptake was observed after TSH treatment of cells in monolayer or when follicle formation was induced without TSH. TSH stimulation of follicles, however, significantly increased iodide uptake ( approximately 4. 4-fold; P<0.001). Compared with iodide uptake in monolayers, the combination of follicle formation and TSH treatment stimulated iodide uptake synergistically to 12.0-fold (P<0.001). NIS messenger RNA (mRNA) and protein levels were almost the same in both monolayer cells and follicles. TSH treatment of monolayers and follicles produced significant (P<0.05) stimulation of mRNA ( approximately 4. 8- and approximately 4.3-fold respectively) and protein ( approximately 6.8- and 4.9-fold respectively). TSH stimulated NIS protein levels in both monolayer and follicles, however, stimulation of functional iodide uptake was only seen with TSH stimulation of follicles. The function of NIS may involve post-transcriptional events, such as intracellular sorting, membrane localization of NIS or another NIS regulatory factor. Polarized functions, such as iodide efflux into follicular lumina, may also contribute to the increased iodide concentration after follicle formation.
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Affiliation(s)
- T Kogai
- Endocrinology Division, West Los Angeles VA Medical Center and UCLA School of Medicine, Los Angeles, California 90073, USA
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Morwood DT, Nichter LS, Hyman S, Bindiger A, Miller JH, McComb JG. Omental transfer to the brain: an experimental study in hydrocephalic rabbits. Ann Plast Surg 1999; 42:174-9. [PMID: 10029483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Hydrocephalus is a common and potentially lethal condition in children that results from an imbalance between absorption and production of cerebral spinal fluid (CSF). Silastic shunts are inserted to drain excess CSF, but they are prone to a number of problems, and at times may be unreliable and ineffective. This study examines the physiological basis of a pedicled omental transfer to the brain as a functional conduit for CSF in an experimentally induced hydrocephalic rabbit model. The ability of the omentum to transport CSF from the subarachnoid space was tested using radioactive tracer substances: radio-iodinated serum albumin (125I-RISA), chromium 51-ethylenediaminetetraacetate (51Cr-EDTA), and technetium 99m (99mTc) glucoheptonate. Immediate ability of exteriorized omentum to transport artificial CSF, as well as transposed omental transport of subarachnoid CSF at 1 month, were examined. Nuclear scan measurements were correlated with clinical observation and a double-blind histological analysis with trichrome and hematoxylin-eosin stain. Exteriorized omentum rapidly absorbed 99mTc glucoheptonate-labeled artificial CSF, with a rapid appearance in the systemic circulatory and urinary systems. Transposed omentum to the brain in animals with artificially created hydrocephalus showed evidence of CSF-labeled 125I-RISA and 51Cr-EDTA absorption in those animals demonstrating histologically viable omentum.
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Affiliation(s)
- D T Morwood
- Division of Plastic Surgery, Childrens Hospital Los Angeles, University of Southern California School of Medicine, USA
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Cornford EM, Hyman S, Cornford ME, Damian RT, Raleigh MJ. A single glucose transporter configuration in normal primate brain endothelium: comparison with resected human brain. J Neuropathol Exp Neurol 1998; 57:699-713. [PMID: 9690674 DOI: 10.1097/00005072-199807000-00007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [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: 11/25/2022] Open
Abstract
Cellular distribution of the Glut1 glucose transporter in normal primate brains was analyzed by immunogold electron microscopy. Two configurations of endothelial Glut1 glucose transporter (high and low density capillaries) have been found in resections of traumatically injured and epileptogenic human brain; the objective of the present study was to ascertain whether these same 2 capillary populations, expressing high and low glucose transporter densities, were the common configuration in normal brain. The relative numbers of Glut1 glucose transporter-associated gold particles on luminal and abluminal endothelial cell membranes were determined within the cerebral cortex of several normal, nonhuman primates. Low Glut1 densities were seen in brain endothelia of both the rhesus and squirrel monkey cortex, with slightly greater quantities of Glut1 in vervet monkey cortices. The Glut1 transporter was most highly expressed in the baboon cortex, approaching the concentrations seen in human brains. In the rhesus, squirrel, and vervet monkeys, Glut1 concentrations were greater on the abluminal than luminal capillary membranes. In contrast, mean luminal membrane Glut1 concentrations were greater in baboons, resembling the distribution seen in the human brain. Brain regional differences in transporter concentration were seen in comparing membrane densities in the baboon cortex (approximately 15 Glut1-gold particles per micrometer), hippocampus (approximately 12 Glut1 gold particles per micrometer), cerebellum (approximately 6 Glut1-gold particles per micrometer), and retinal microvasculature (approximately 20 Glut1-gold particles per micrometer). We conclude that a single, uniform Glut1 distribution characterizes brain capillaries of normal nonhuman primates, and hypothesize that the presence of high and low density glucose transporter endothelial cells (seen in human traumatic injury and seizure resections) represents a pathologic response to brain insult.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095, USA
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Abstract
The objective of the present study was to define the cellular location of the Glut1 glucose transporter in the primate choroid plexus. Immunogold electron microscopy indicated that Glut1 epitopes were associated primarily with choroid plexus endothelial cells. Digitized analyses of electron microscopic images provided quantitative estimates of the relative number of Glut1 glucose transporter epitopes on luminal and abluminal endothelial cell membranes within the choroid plexuses. We recorded a high density of Glut1 in the microvascular endothelium of primate choroid plexus, which was consistent in vervet monkeys (5-10 Glut1 gold particles per micrometer of endothelial cell plasma membrane), as well as in baboons (5-20 Glut1 gold particles per micrometer of capillary plasma membrane). In the baboon choroid plexus, we observed that perivascular cells (presumed to be pericytes) were also Glut1-positive, but with substantially reduced activity compared with endothelial cells. Occasional Glut1-immunogold particles were also seen in the basolateral membranes of the choroid plexus cuboidal cells. Light microscopic immunocytochemistry confirmed the abundance of Glut1 immunoreactivity in choroid plexus endothelial cells of vervet monkeys and baboons. A similar pattern was observed in surgically resected human choroid plexus, suggesting differences between primates, including humans and laboratory animals. The only difference was that erythrocytes within the human choroid plexus exhibited a florid Glut1-positive response, but were weakly immunoreactive in nonhuman primates. The observation of high glucose transporter densities in choroid plexus endothelial cells is consistent with the suggestion that choroidal epithelia and capillaries provide a metabolic work capability for maintaining ionic gradients and secretory functions across the blood-CSF barriers.
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Affiliation(s)
- E M Cornford
- Department of Neurology and the Brain Research Institute, UCLA School of Medicine, Los Angeles, CA 90095, USA
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Cornford EM, Hyman S, Cornford ME, Landaw EM, Delgado-Escueta AV. Interictal seizure resections show two configurations of endothelial Glut1 glucose transporter in the human blood-brain barrier. J Cereb Blood Flow Metab 1998; 18:26-42. [PMID: 9428303 DOI: 10.1097/00004647-199801000-00003] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Immunogold electron microscopy was used to analyze and quantify the Glut1 glucose transporter in brain tissue from five patients undergoing surgery for treatment of seizures. Samples were prepared from two different regions of each resection: (1) the most actively spiking epileptogenic site, and (2) the least actively spiking region, as indicated by intraoperative EEG monitoring. Two configurations of endothelial cell Glut1 were observed. About one half of the capillary profiles examined displayed abundant Glut1 immunoreactivity on both luminal and abluminal endothelial membranes. In the remainder of the profiles, reduced Glut1 labeling was seen, but adjacent erythrocyte membranes remained highly Glut1 immunoreactive, suggesting that reduced endothelial Glut1 reactivity was not attributable to method artifacts. Immunogold studies using antisera to human glial fibrillary acidic protein and human serum albumin demonstrated increased quantities of these two epitopes in the extravascular regions in which more EEG spiking activity had been demonstrated. These observations were consistent with the hypotheses that capillary integrity was more compromised, and gliosis was quantitatively increased, in the more actively spiking region of the resection. Altered glucose transporter activity in the blood-brain barrier was characterized by a bimodal Glut1 distribution in which the smaller (type B) endothelial cells displayed low Glut1 immunoreactivity, whereas adjacent (and even contiguous) larger (type A) endothelial cells showed 5- to 10-fold greater expression of membrane Glut1 transporter protein. Because this transporter facilitates glucose entry to the brain, small pericapillary volumes of brain tissue may have quite different concentrations of glucose. We hypothesize that in complex partial seizures and other forms of brain insult, an alteration of blood-brain barrier Glut1 glucose transporter activity is indicated by the appearance of these two subpopulations of endothelial cells. In comparison with previous studies of human brain capillaries in hemangioblastoma and brain injury, endothelial Glut1 density was apparently reduced (interictally) in affected temporal lobes of patients with complex partial seizures.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine, USA
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Abstract
The objective of the present study was to examine the apparent work capacity of one of the two separate membrane systems (the blood-cerebrospinal fluid barrier) that isolate the mammalian brain extracellular fluid (and cerebrospinal fluid, CSF) from plasma. Digitized analyses of electron-microscopic images provided estimates of mitochondrial volumes, which were expressed as a percentage of the cell cytoplasm. We recorded a high mitochondrial content of 12-15% in the cuboidal epithelium of primate choroid plexus, which was consistent in vervet, rhesus, and squirrel monkeys, as well as in baboons. Similarly high mitochondrial contents were observed in the rabbit, rat, and mouse choroid plexus. It has been postulated that the high mitochondrial content of brain endothelium is associated with maintaining the ionic gradients within the central nervous system. We observed that the mitochondrial content of the choroid plexus (where CSF is produced) was slightly higher than in (prior measurements of) the blood-brain barrier (BBB). In addition, surface areas at the apical borders of the choroid plexus epithelia (where the Na+K+ATPase activity has been localized) were increased 7- to 13-fold over the basal borders, in the primate species examined. The observation of high mitochondrial volumes in choroid plexus cells is consistent with the suggestion that increased mitochondrial densities seen in choroidal epithelia and BBB capillaries provide a metabolic work capability for both secretory activities and maintaining ionic gradients across blood-CSF barriers.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095, USA
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Abstract
The principal glucose transporter at the blood-brain barrier (BBB) is the Glut1 isoform, and transporter density is believed to be an index of cerebral metabolic rate. In the present study, glucose transporter expression was studied in tissue resected 7-8 h after acute traumatic brain injuries in 2 patients. Light microscopic immunochemistry indicated a zone of complete loss of the Glut1 glucose transporter isoform in microvessel endothelial cells adjacent to sites of small vessel injury, concentrically surrounded by a narrow zone of variable Glut1, and distally surrounded by capillaries with typically immunoreactive endothelia in nondisrupted parenchyma. Variably reactive capillaries displayed alternating sectors of greatly reduced and highly reactive Glut1 density, suggesting a high density and low density of transporter activity in contiguous endothelial cells. Quantitative electron microscopic immunogold analyses demonstrated that the transporter was predominantly localized to the luminal and abluminal endothelial membranes, with lesser reactivity in cytoplasm; pericyte Glut1 was minimally above background levels. In endothelial sectors with reduced Glut1 transporter immunoreactivity, the luminal:abluminal ratio of Glut1 epitòpes was less than unity; while it is greater than unity in highly reactive endothelial cells. The number of Glut1-immunoreactive sites per micrometer of capillary membrane was not significantly different from previous reported Glut1 density in seizure resections, and about 2- to 3-fold higher than in human red cells. In the same tissue samples, qualitative immunogold electron microscopy of human serum albumin indicated leakage of this protein (MW 65,000) from the vascular space into pericapillary regions. Thus the high Glut1 density observed in capillaries from acutely injured brain occurs concomitantly with compromised barrier function.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine 90095, USA
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Cornford EM, Hyman S, Black KL, Cornford ME, Vinters HV, Pardridge WM. High expression of the Glut1 glucose transporter in human brain hemangioblastoma endothelium. J Neuropathol Exp Neurol 1995; 54:842-51. [PMID: 7595657 DOI: 10.1097/00005072-199511000-00011] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [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] Open
Abstract
The principal glucose transporter at the blood-brain barrier is Glut1, and GLUT1 expression is downregulated in high grade gliomas. In the present study, glucose transporter expression was studied in surgically resected hemangioblastoma tissue. Light microscopic immunochemistry indicated the high expression of the Glut1 glucose transporter isoform throughout the central vascular endothelium of this tissue. Glial fibrillary acidic protein (GFAP) was observed only at the tumor border, with no GFAP immunoreactivity in stromal cells, pericytes or endothelia in the central tumor regions. It is generally believed that more Glut1 is found in erythrocytes than any other cell, but quantitative electron microscopic immunogold analyses of Glut1-immunoreactive sites per micron of capillary membrane showed the Glut1 density in tumor endothelial membranes glucose transporter was 2-3-fold higher than in human red cells. In the same tissue samples, qualitative immunogold electron microscopy of human serum albumin indicated that this protein (MW 65,000) moved freely from the vascular space into pericapillary regions, confirming the leaky barrier characteristics of the hemangioblastoma. These studies show that Glut1 expression may be high in endothelia that are highly permeable and devoid of astroglial contacts. Thus, human cerebral hemangioblastomas may provide a novel system for studying the induction of Glut1 in the blood-brain barrier.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine, USA
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Cornford EM, Hyman S, Cornford ME, Clare-Salzler M. Down-regulation of blood-brain glucose transport in the hyperglycemic nonobese diabetic mouse. Neurochem Res 1995; 20:869-73. [PMID: 7477681 DOI: 10.1007/bf00969700] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [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: 01/25/2023]
Abstract
The intracarotid injection method has been utilized to examine blood-brain barrier (BBB) glucose transport in hyperglycemic (4-6 days) mice. In anesthetized mice, Brain Uptake Indices were measured over a range of glucose concentrations from 0.010-50 mmol/l; glucose uptake was found to be saturable and kinetically characterized. The maximal velocity (Vmax) for glucose transport was 989 +/- 214 nmol.min-1.g-1. and the half-saturation constant estimated to be 5.80 +/- 1.38 mmol/l. The unsaturated Permeability Surface area product (PS) is = 171 + 8 microliters.min.-1.g-1. A rabbit polyclonal antiserum to a synthetic peptide encoding the 13 C-terminal amino acids of the human erythrocyte glucose transporter immunocytochemically confirmed the presence of the GLUT1 isoform in non-obese diabetic (NOD) mouse brain capillary endothelia. These studies indicate that a down-regulation of BBB glucose transport occurs in these spontaneously hyperglycemic mice; both BBB glucose permeability (as indicated by PS product) and transporter maximal velocity are reduced (in comparison to normoglycemic CD-1 mice), but the half-saturation constant remains unchanged.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine 90095, USA
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Abstract
The commonly held notion that Rett syndrome (RS) is a neurodegenerative disorder with normal early development was examined by an epidemiological survey and review of medical records and serial neurological and development evaluations. In some subjects, deviance from normal development was evident from the perinatal period, and gradually became more prominent with age. These findings are convincing when seen in conjunction with a reduction in velocity of brain growth, as early as 2-4 months of life, well before the recognition of gross neurological deficits. Neurodevelopmental evaluations provide no indication that there is progressive loss of adaptive behaviors, or communication skills to indicate a neurodegenerative process. Taken together with the known neuropathological and neurochemical changes in RS brain we hypothesize that RS is a neurodevelopmental disorder, which has a genetic basis, and affects subsets of neurons and their connections during a period of vigorous brain growth, when synapse formation and pruning are at a peak. Studies of mitochondrial (mt) DNA in brain to understand the genetic mechanisms underlying matrilineal inheritance in the few familial cases, and mt structural and enzyme deficiencies have been unrevealing to date.
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Affiliation(s)
- S Naidu
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, USA
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20
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Abstract
Blood-brain barrier (BBB) glucose transport rates were measured using the intracarotid injection method in newborn, 14-day-old suckling, 28-day-old weanling and adult rabbits, and compared with membrane transporter density. Light microscope immunochemistry confirmed the presence of the GLUT1 glucose transporter isoform in these rabbits. Quantitative electron microscopic immunogold analyses of GLUT1-immunoreactive sites per micrometer of capillary membrane indicated GLUT1 density increased with age, and correlated with in vivo measurements of Vmax. Maximal transport velocities (Vmax) of glucose transfer (an indicator of the activity and relative number of transporter proteins) increased significantly (P = 0.05) with age: in neonates Vmax = 0.61 mumol.min-1.g-1, in sucklings Vmax = 0.68 mumol.min-1.g-1, in weanlings Vmax = 0.88 mumol.min-1.g-1, and in adults Vmax = 1.01 mumol.min-1 g-1. Cerebral blood flow (CBF) rates, increased with age from 0.19 and 0.26 ml.min-1.g-1 in neonates and sucklings to 0.51 (weanlings) and 0.70 (adults) ml.min-1.g-1. Non-linear regression analyses indicated the half-saturation constant (Km) for glucose transport ranged from 13 mM in adult rabbits to 19 mM in 14-day-old sucklings: differences in Km were not significant. Age-related changes in the Permeability-Surface Area product (PS +/- S.E.) of both water and glucose were also seen. At all ages studied, the diffusion component (Kd) of glucose uptake was not distinguishable from zero. We conclude developmental up-regulation of the rabbit BBB glucose transporter is characterized by no changes in transporter affinity, and provide the first demonstration of increased membrane transporter proteins correlating with an age-related increase (65%) in glucose transporter maximal velocity.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine 90024
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21
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Abstract
Immunogold electron microscopy was used to examine human brain resections to localize the GLUT1 glucose transporter. The tissue examined was obtained from a patient undergoing surgery for treatment of seizures, and the capillary profiles examined had characteristics identical to those described previously for active, epileptogenic sites (confirmed by EEG analyses). A rabbit polyclonal antiserum to the full-length human erythrocyte glucose transporter (GLUT1) was labeled with 10-nm gold particle-secondary antibody conjugates and localized immunoreactive GLUT1 molecules in human brain capillary endothelia, with < 0.25% of the particles beyond the capillary profile. Erythrocyte membranes were also highly immunoreactive, whereas macrophage membranes were GLUT1-negative. The number of immunoreactive sites per capillary profile was observed to be 10-fold greater in humans than in previous studies of rat and rabbit brain capillaries. In addition, half of the total number of immunoreactive gold particles were localized to the luminal capillary membrane. We suggest that the blood-brain barrier GLUT1 glucose transporter is up-regulated in seizures, and this elevated transporter activity is characterized by increased GLUT1 transporters, particularly on the luminal capillary membranes. In addition, acute modulation of glucose transporter activity is presumed to involve translocation of GLUT1 from cytoplasmic to luminal membrane sites, demonstrable with quantitative immunogold electron microscopy.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine
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Cornford EM, Hyman S, Pardridge WM. An electron microscopic immunogold analysis of developmental up-regulation of the blood-brain barrier GLUT1 glucose transporter. J Cereb Blood Flow Metab 1993; 13:841-54. [PMID: 8360290 DOI: 10.1038/jcbfm.1993.106] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Electron microscopy was used to quantitate blood-brain barrier (BBB) glucose transporters in newborn, 14-day-old suckling, 28-day-old weanling, and adult rabbits. A rabbit polyclonal antiserum to a synthetic peptide encoding the 13 C-terminal amino acids of the human erythrocyte glucose transporter (GLUT1) was labeled with 10-nm gold particle-secondary antibody conjugates and localized immunoreactive GLUT1 molecules in rabbit brain capillary endothelia. Three distinct populations of brain capillary profiles were identified in newborn rabbits: prepatent capillary buds, partially patent capillaries with highly amplified luminal membranes, and patent capillaries. Immunogold analyses indicated that the GLUT1 transporter abundance positively correlated with capillary developmental status. The mean number of gold particles per capillary profile increased at each developmental age examined, suggesting that developmental up-regulation of the BBB glucose transporter occurred in rabbits. GLUT1 immunoreactivity was three- to fourfold greater on the abluminal than luminal capillary membranes among all ages examined. Changes in the proportions of GLUT1 transporter were also seen, and possible reasons for the postnatal decrease in the percentage of cytoplasmic GLUT1 transporter are discussed. The numbers of cytoplasmic and membrane-associated immunogold particles increased with age. We conclude that regulatory modulations of BB glucose transport may be characterized by increases in BBB glucose transporter density with age and state of development. In addition, modulation of glucose transporter activity may be reflected by minor postnatal shifts of GLUT1 from cytoplasmic to membrane compartments, which can be demonstrated with quantitative immunogold electron microscopy.
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Affiliation(s)
- E M Cornford
- Department of Neurology, UCLA School of Medicine
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23
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Abstract
The intracarotid injection method has been utilized to examine blood-brain barrier (BBB) glucose transport in normal mice, and after a 2-day fast. In anesthetized mice, cerebral blood flow (CBF) rates were reduced from 0.86 ml.min-1 x gm-1 in control to 0.80 ml.min-1 x gm-1 in fasted animals (p > 0.05). Brain Uptake Indices were significantly (p < 0.05) higher in fasted (plasma glucose = 4.7 mM) than control (plasma glucose = 6.5 mM) mice, while plasma glucose was significantly lower. The maximal velocity (Vmax) for glucose transport was 1562 +/- 303 nmoles.min-1 x g-1, and the half-saturation constant (Km =) 6.67 +/- 1.46 mM in normally fed mice. In fasted mice the Vmax was 2053 +/- 393 nmoles.min-1 x g-1 (p > 0.05), and the half-saturation constant (Km =) 7.40 +/- 1.60 mM (not significant, P > 0.05). A rabbit polyclonal antiserum to a synthetic peptide encoding the 13 C-terminal amino acids of the human erythrocyte glucose transporter (GLUT-1) immunocytochemically confirmed that the mouse brain capillary endothelial glucose transporter is a GLUT-1 transporter, and immunoreactivity was similar in brain endothelia from fed and fasted animals. In conclusion, after a 2-day fast in the mouse, we saw significant reductions in forebrain weight (7%), and plasma glucose levels (27%). Increased brain glucose extraction (25%, p < 0.05), and a 22% increase in the unsaturated permeability-surface area product (p < 0.05) was also observed.
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Affiliation(s)
- E M Cornford
- Southwestern Regional V.A. Epilepsy Center, Veterans Administration West Los Angeles Medical Center, CA 90073
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Abstract
Photodynamic therapy is a therapeutic modality long studies for its application to the treatment of malignant neoplasms. Recently, studies have suggested its potential use in the treatment of atherosclerosis. In this study, two atherosclerotic plaques were induced in the abdominal aortas of 35 rabbits. The animals then received Photofrin II (Quadralogic Technologies Inc., Pearl River, NY), a photosensitizer, at doses of 5 mg/kg and 2.5 mg/kg. After 48 hours, the plaques were irradiated by a fiberoptic connected to an argon ion laser. Fluency rates from 32 mW to 256 mW and energy doses from 1.6 to 60 joules were applied. Only one of the paired plaques was irradiated, the other remaining as a control. Four weeks after treatment, the vessels were assessed. Of 26 plaques treated with photodynamic therapy, 22 were no longer grossly visible, while the nine animals that received light irradiation but no Photofrin II all had visible plaque (P < 0.001). Studies of the vessel sections confirmed a reduction in intimal thickness from 0.74 +/- 0.15 mm in matched controls as compared with 0.51 +/- 0.13 mm in animals with treated plaques. There was a concomitant enlargement of the luminal diameter from 1.13 +/- 0.51 to 1.41 +/- 0.72. On the microscopic level, plaque reduction was most complete in the groups treated with 40 and 60 joules. Different fluency rates and drug dosages did not lead to differing outcomes. Our findings indicate that photodynamic therapy with dihematoporphyrin ether met our goal of reducing plaque size and may represent a means of treating atherosclerotic plaques.
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Affiliation(s)
- G Tang
- Department of Neurological Surgery, University of Southern California School of Medicine, Los Angeles
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25
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Bauer TS, Hamers R, Boberg P, Breuer H, Geerling F, Hyman S, Konijn J, Lefevere Y, Taal A, Visschers JL, Ykema R. Pion absorption followed by multinucleon emission. Phys Rev C Nucl Phys 1992; 46:R20-R24. [PMID: 9968129 DOI: 10.1103/physrevc.46.r20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Khandaker MA, Kelly JJ, Boberg P, Feldman AE, Flanders BS, Hyman S, Seifert H, Karen P, Norum BE, Welch P, Nanda S, Saha A. Neutron and proton transition densities from 32,34S(p,p') at Ep=318 MeV. II. Neutron densities for 34S. Phys Rev C Nucl Phys 1991; 44:1978-1994. [PMID: 9967621 DOI: 10.1103/physrevc.44.1978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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28
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Kelly JJ, Khandaker MA, Boberg P, Feldman AE, Flanders BS, Hyman S, Seifert H, Karen P, Norum BE, Welch P, Nanda S, Saha A. Neutron and proton transition densities from 32,34S(p,p') at Ep=318 MeV. I. Isoscalar densities for 32S. Phys Rev C Nucl Phys 1991; 44:1963-1977. [PMID: 9967620 DOI: 10.1103/physrevc.44.1963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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29
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Ellenberg M, Gardin H, Hyman S, Chodoroff G. Orthodromic vs. antidromic latencies. Arch Phys Med Rehabil 1991; 72:431-2. [PMID: 2059114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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30
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Zlokovic BV, Hyman S, McComb JG, Tang G, Rezai AR, Weiss MH. Vasopressin uptake by hypothalamopituitary axis and pineal gland in guinea pigs. Am J Physiol 1991; 260:E633-40. [PMID: 1902062 DOI: 10.1152/ajpendo.1991.260.4.e633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The uptake of circulating arginine vasopressin (AVP) by the pituitary gland (anterior lobe), pineal gland, and hypothalamus (ventromedial part) was investigated in an isolated in situ perused brain of anesthetized guinea pig. Kinetic experiments revealed saturable AVP uptake in all studied regions with Km values of 0.79, 0.19, and 0.76 microM and maximum velocity values of 22, 2.1, and 1.6 pmol.min-1.g-1 for the pituitary gland, pineal gland, and hypothalamus, respectively. The nonsaturable components (diffusion constants) were not significantly different from zero. Peptide fragments, L-phenylalanine, and Bestatin (an aminopeptidase inhibitor) did not interfere with AVP uptake. However, uptake of AVP was strongly inhibited in the presence of the V1 antagonist [1-(beta-mercapto-beta-beta-cyclopentamethylenepropionic acid), 2-(O-methyl)tyrosine]AVP at 2.7 microM, and regional Ki values, assuming that the observed inhibitions were purely competitive, ranged between 0.32 and 2.23 microM. The V2 agonist 1-desamino-8-D-AVP at 2.7 microM produced only a weak inhibition of AVP uptake, and regional Ki values ranged between 9.56 and 21.3 microM. It is concluded that specific uptake mechanisms in the hypothalamopituitary axis and pineal gland are sensitive enough to detect blood-borne AVP under the physiological hormonal state. It is suggested that AVP binding in situ is primarily related to V1 receptors, which may be involved in mediating the central effects of this circulating peptide.
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Affiliation(s)
- B V Zlokovic
- Division of Neurosurgery, Children's Hospital of Los Angeles, California
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31
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Abstract
Uptake of circulating arginine vasopressin (AVP) by choroid plexus was studied by means of the in situ brain perfusion technique in anesthetized guinea pig and by means of single-circulation paired-tracer dilution technique in isolated perfused sheep choroid plexus. Kinetic analysis revealed saturable AVP uptake with Michaelis constant (Km) values of 32 +/- 4 and 31 +/- 5 nM and maximal saturable influx rate (Vmax) of 0.45 +/- 0.06 and 12.1 +/- 0.67 pmol.min-1.g-1 in guinea pig and sheep choroid plexus, respectively. The peptide fragments AVP-(1-8) and [pGlu4,Cyt6]AVP-(4-9), the amino acids L-phenylalanine, L-tyrosine, and 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid, and the aminopeptidase inhibitors Bestatin and bacitracin did not influence hormone kinetics. However, the V1 antagonist [(1-beta-mercapto-beta,beta-cyclo-pentamethylenepropionic acid)-O-methyl-Tyr2]AVP significantly inhibited AVP uptake with inhibitor constant (Ki) values of 0.19 +/- 0.03 (guinea pig) and 0.07 +/- 0.01 microM (sheep). The V2 agonist 1-desamino-8-D-AVP and pressinoic acid produced weak inhibitions only in guinea pig choroid plexus, and Ki/Km ratios indicated 220 and 310 times lower affinities than for AVP, respectively. It is suggested that the membrane mechanism responsible for AVP uptake in choroid plexus has a binding site with properties similar to those of V1 receptor.
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Affiliation(s)
- B V Zlokovic
- Division of Neurosurgery, Children's Hospital of Los Angeles, California
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Jenike MA, Hyman S, Baer L, Holland A, Minichiello WE, Buttolph L, Summergrad P, Seymour R, Ricciardi J. A controlled trial of fluvoxamine in obsessive-compulsive disorder: implications for a serotonergic theory. Am J Psychiatry 1990; 147:1209-15. [PMID: 2143637 DOI: 10.1176/ajp.147.9.1209] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Thirty-eight patients with primary obsessive-compulsive disorder participated in a 10-week, double-blind, placebo-controlled trial of the potent, selective serotonin reuptake inhibitor fluvoxamine. Fluvoxamine was significantly better than placebo on two of three measures of improvement in obsessive-compulsive symptoms. The authors also compared studies of the serotonergic agents fluvoxamine, sertraline, fluoxetine, and clomipramine and found that a greater effect size was associated with less serotonergic specificity and that some ability to affect other neurotransmitter systems may be a necessary but not sufficient requirement for antiobsessional activity. These data lend only partial support to a serotonin hypothesis of obsessive-compulsive disorder.
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Zlokovic BV, Hyman S, McComb JG, Lipovac MN, Tang G, Davson H. Kinetics of arginine-vasopressin uptake at the blood-brain barrier. Biochim Biophys Acta 1990; 1025:191-8. [PMID: 2364078 DOI: 10.1016/0005-2736(90)90097-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Uptake of arginine-vasopressin, VP, at the luminal side of the blood-brain barrier (BBB) was studied by means of an in situ brain perfusion technique in the guinea-pig. Kinetic experiments revealed a saturable peptide influx into the parietal cortex, caudate nucleus and hippocampus with Km between 2.1 and 2.7 microM, and Vmax ranging from 4.9 to 5.6 pmol.min-1.g-1. The non-saturable component, Kd, was not significantly different from zero. Influx of VP into the brain was not altered by the presence of the peptide fragments: VP-(1-8), pressinoic acid and [pGlu4,Cyt6]VP-(4-9) at 4.5 microM, nor yet by the aminopeptidase inhibitor, bestatin (0.5 mM) and the L-amino acid transport system substrates, L-tyrosine and L-phenylalanine at 5 mM. At a perfusate concentration of 4.5 microM, the V1-vasopressinergic receptor antagonist, d(CH2)5[Tyr(Me)2]VP, reduced VP influx; regional Ki values, assuming that the observed inhibitions were purely competitive, ranged between 4.7 and 8.5 microM. It is concluded that there is an apparent cerebrovascular permeability to circulating VP due to the presence of a carrier-mediated transport system for the peptide located at the luminal side. The mechanism for VP BBB uptake exhibits no affinity for peptide fragments and large neutral amino acids, but requires reception of the intact molecule, which may be the same initial step for both the BBB VP transporter and the V1-receptor.
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Affiliation(s)
- B V Zlokovic
- Department of Neurological Surgery, Childrens Hospital Los Angeles, CA
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Zlokovic BV, Segal MB, Davson H, Lipovac MN, Hyman S, McComb JG. Circulating neuroactive peptides and the blood-brain and blood-cerebrospinal fluid barriers. Endocrinol Exp 1990; 24:9-17. [PMID: 2193795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Interactions of radiolabelled circulating neuroactive peptides: enkephalin-leucine (Enk-Leu), delta sleep inducing peptide (DSIP), thyrotropin-releasing hormone (TRH) and vasopressin-arginine (VP-Arg) with the blood-brain and blood-cerebrospinal fluid barriers were studied by mean of: 1. a vascular perfusion technique in the guinea-pig using multiple-time brain uptake analysis, 2. a vascular perfusion technique of the in situ isolated choroid plexus from sheep using single-circulation paired-tracer dilution or steady-state analysis. It has been demonstrated that Enk-Leu, DSIP and VP-Arg were taken up intact at the luminal side of the blood-brain barrier and blood-tissue interface of the blood-cerebrospinal fluid barrier by a saturable mechanism. On the other hand, a non-saturable mechanism as well as possible enzymatic degradation were shown during TRH interactions with either the blood-brain or blood-cerebrospinal fluid barriers. It is concluded that both, facilitated and simple diffusion, govern circulating neuroactive peptide uptake into the central nervous system.
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Affiliation(s)
- B V Zlokovic
- Department of Medical Physiology, Faculty of Medicine, Belgrade, Yugoslavia
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Abstract
Clinical, biochemical and pathological studies in patients with the Rett syndrome (RS) are presented. The neuropathological changes and alterations in neurotransmitter markers are particularly interesting and provide valuable information that may be helpful in understanding the behavior and neurological phenotype of RS.
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Affiliation(s)
- S Naidu
- Kennedy Institute, Department of Neurology, Johns Hopkins University, Baltimore, MD 21205
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36
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Abstract
An increasing number of physiological and morphological studies indicate that cerebrospinal fluid (CSF) drains via nonarachnoidal pathways in several mammalian species. Ultrastructural tracer studies were undertaken to examine the orbital route for CSF absorption in the rabbit. At the termination of the optic nerve subarachnoid space, an area of connective tissue containing numerous small tortuous channels is present. Ferritin (molecular weight 400,000) infused into the ventricles at normal and increased intraventricular pressure was present in these channels by 15 minutes postinfusion, and subsequently reached the intraorbital connective tissue. Elevating the intraventricular pressure did not noticeably alter the morphological appearance of this region or change the gross distribution pattern of the ferritin. Ferritin did not penetrate the scleral barrier to reach the choriocapillaris, nor did it breach the arachnoid barrier layer proximal to the transitional zone at the optic subarachnoid space to reach the dura mater. These results are very similar to those described for the hamster orbital region and the rabbit cribriform region. These experiments support the concept that macromolecules exit the subarachnoid space at the termination of the optic nerve via open channels, and that no significant barrier to drainage of macromolecules in CSF is present at this location.
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Affiliation(s)
- S S Erlich
- Department of Neurological Surgery, University of Southern California School of Medicine, Los Angeles
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37
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Abstract
Clinically, there appears to be a significant reduction in cerebrospinal fluid (CSF) formation during acute ventriculitis--an observation that has not been well documented by experimental studies. To examine this phenomenon, an inoculum of Escherichia coli was injected into the lateral ventricles of New Zealand White rabbits. Approximately 18 hours later, the survivors (64%) underwent a 3-hour ventriculocisternal perfusion of carbon-14-dextran (MW 7 X 10(4)) as a reference marker for CSF formation. On the average, CSF formation in this experimental group was reduced by one-half to two-thirds of normal, confirming the clinical observation. Histologically, the stroma of the choroid plexus was the site of an extensive inflammatory infiltrate. Meningitis, ependymitis, and focal encephalitis completed the picture. Vasculitis was not present in the choroid plexus. The epithelium of the choroid plexus underwent patchy cellular swelling or frank necrosis and destruction. It is postulated that the changes in the choroid plexus caused by the inflammatory process were responsible for the diminished CSF formation in this acute setting. Reduced choroidal blood flow and/or enterotoxin may play a role in these alterations.
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Affiliation(s)
- R E Breeze
- Department of Neurosurgery, University of Southern California School of Medicine, Los Angeles
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38
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Danzig D, Francis L, Elkind S, Hyman S, Mendes M, Boutnazos C, Legg E, Mendelson M. Trends in isolation and precautions over a three-year period. Am J Infect Control 1989. [DOI: 10.1016/0196-6553(89)90104-1] [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]
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Wong DW, Mandal A, Brown J, Reese IC, Siegler R, Hyman S. In vivo assessment of 111In-labeled hematoporphyrin derivative in breast tumor-bearing animals. Int J Rad Appl Instrum B 1989; 16:269-81. [PMID: 2523878 DOI: 10.1016/0883-2897(89)90008-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The biological behavior of 111In-labeled HPD has been investigated in tumor-bearing animals. Mice mammary adenocarcinomas and 7,12-dimethylbenz(a)anthracine induced breast tumors in Sprague-Dawley female rats were clearly visualized by 111In-HPD nuclear scintigraphy. Optimal scans were obtained after a 48 h delay. In normal and tumor-bearing animals, the highest uptake of 111In-HPD 72 h post-injection was found in the liver, the spleen and the kidneys. Depending on the size and the extent of necrosis, the uptake of 111In-HPD by malignant breast tumors varied from 2.5% injected dose (ID) (range 0.14-5.3% ID) in mice to 1% (range 0.22-8.1% ID) in rats. Benign breast tumor uptake of 111In-HPD was less than 1% ID. No significant amount of the radiopharmaceutical was found in pulmonary abscesses and abdominal cysts (less than 0.1% ID). Scintigrams of these infectious or inflammatory lesions were normal. Malignant tumor to blood, heart and lung ratios averaged 50:1, 10:1 and 3:1 respectively. Tumor to brain ratio ranged from 72 to 444:1.
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Affiliation(s)
- D W Wong
- Department of Radiology, King/Drew Medical Center, U.C.L.A. 90059
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Wong DW, Hyman S, Reese I, Brown JE, Vasinrapee P, Siegler R, Giannotta S. Scintigraphic detection of atherosclerotic plaques in rabbits with 111In-labeled hematoporphyrin derivative. Int J Rad Appl Instrum B 1989; 16:511-7. [PMID: 2530194 DOI: 10.1016/0883-2897(89)90065-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The efficacy of 111In-labeled hematoporphyrin derivative (HPD) in localizing and detecting atheromas had been investigated with 10 atherogenic New Zealand white rabbits. Atherosclerotic plaques surgically induced in the abdominal aorta showed selective uptake of 111In-HPD over normal blood vessels averaging 0.01% ID/g tissue (range 0.003-0.023% ID/g). Normal aorta and thoracic artery concentrated an average of 0.0026% ID/g which is less than the mean blood activity of 0.0034% ID/mL. Statistical analysis demonstrated significant difference in the uptake of 111In-HPD by the atherosclerotic plaque segments as compared to normal abdominal aorta (P = 0.0023) and normal thoracic artery (P = 0.0012). In hypercholesteremic rabbits, the mean plaque segment to normal blood vessels ratio was 4:1 (range 2 to 9:1) sufficiently high to permit plaque delineation in the scintigram. Although 111In-HPD showed promise as a plaque imaging agent, further investigation with large animal models such as primates is needed to confirm current findings.
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Affiliation(s)
- D W Wong
- Department of Radiology, King/Drew Medical Center, UCLA 90059
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Abstract
Atherosclerotic plaques were induced in abdominal aortas of rabbits. At 8 weeks, 5 mg of dihematoporphyrin ether (Photofrin II) per kg was injected intravenously followed by sacrifice of the animal, fluorescence microscopy, and quantitative assay of porphyrin in the plaque-containing aortas at 1, 12, 24, 48, and 72 hours. Photofrin II was taken up preferentially by the plaque, with the highest plaque to normal wall ratio occurring at 48 hours. Phototherapy was carried out in 13 animals in each of which two plaques had been induced. With a 630-nm light source 48 hours after the infusion of Photofrin, one of the pair of plaques was treated while the other served as a control. Animals were killed at 2, 4, and 6 weeks. The 6-week specimens showed the most dramatic reduction in plaque in comparison to controls. Photodynamic therapy may provide an alternate strategy in dealing with focal atherosclerosis.
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Affiliation(s)
- V Neave
- Department of Neurosurgery, University of Southern California School of Medicine, Los Angeles
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Abstract
Cholera toxin (CT) has been reported to double cerebrospinal fluid (CSF) formation following its introduction into the ventricular system of cats and dogs. In our laboratory we noted that CT used in a similar fashion in rabbits and cats resulted in only a slight increase in CSF formation and was associated with a steadily rising protein content in the cisterna magna effluent. To further investigate this finding, rabbits and cats underwent ventriculo-cisternal perfusions, one group with CT introduced into the ventricles and the other without. In the rabbit only, radioiodinated serum albumin (125I-RISA) was given i.v. Other groups of rabbits had 125I-RISA or 125I-CT injected into the ventricles. The group of rabbits receiving intraventricular CT experienced a 4-10-fold elevation in the amount of both protein and 125I-RISA in the cisterna magna effluent compared with the control group. Electrophoretic pattern of the protein present in the effluent was similar to that of rabbit plasma. Autoradiography of the brains of those animals given intraventricular 125I-CT were found to have a very high uptake of 125I-CT in the choroid plexus and along all exposed ventricular surfaces, a finding not evident when 125I-RISA alone was given intraventricularly. It is concluded that CT altered the blood-CSF barriers allowing the reference marker to penetrate these barriers and plasma to leak into the CSF. These findings appear to account for most if not all of what was thought to be an increase in CSF formation in response to intraventricular CT.
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Affiliation(s)
- S Hyman
- Department of Neurologic Surgery, University of Southern California School of Medicine, Los Angeles 90027
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Wood M, Hyman S, Wood AJ. A clinical study of sensitivity to sodium nitroprusside during controlled hypotensive anesthesia in young and elderly patients. Anesth Analg 1987; 66:132-6. [PMID: 3028217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aging has important effects on the cardiovascular system; baroreceptor reflex function decreases and the elderly are more resistant to both beta-receptor agonists and antagonists. The purpose of the present clinical study was to determine the relationship between age and sensitivity to sodium nitroprusside in 16 patients during deliberate hypotensive anesthesia by determining the blood pressure changes in young and elderly patients to incremental increases in dose of sodium nitroprusside. A dose-response curve relating change in mean blood pressure to dose of sodium nitroprusside (microgram X kg-1 X min-1) was constructed for each patient; the slope of this line is a measure of "sensitivity." The change in mean arterial blood pressure per microgram X kg-1 X min-1 nitroprusside dose (i.e., slope), showed a significant correlation with age (r = 0.766, P less than 0.001), demonstrating that sensitivity to sodium nitroprusside increases with advancing years. The maximum change in heart rate produced by nitroprusside showed a reciprocal correlation with age (r = -0.791, P less than 0.001). There was no significant correlation between age and maximum change in plasma norepinephrine or epinephrine concentrations during nitroprusside infusion. The increased sensitivity to nitroprusside might have been due to diminished baroreflex activity, resistance of cardiac adrenergic receptors to catecholamine stimulation, or alteration in sensitivity to the direct vasodilating effects of sodium nitroprusside. Whatever the mechanism, however, this clinical study has shown that lower doses of nitroprusside should be used in elderly patients to achieve the same degree of hypotension achieved in younger patients.
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Moore JW, Hyman S, Antonarakis SE, Mules EH, Thomas GH. Familial isolated aniridia associated with a translocation involving chromosomes 11 and 22 [t(11;22)(p13;q12.2)]. Hum Genet 1986; 72:297-302. [PMID: 3754537 DOI: 10.1007/bf00290952] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Isolated aniridia segregated as an autosomal dominant trait in a family with 11 affected members spanning five generations. Four of the eight individuals studied had aniridia associated with glaucoma and cataracts. Cytogenetic studies revealed an apparently balanced reciprocal translocation between chromosomes 11 and 22 [t(11;22)(p13;q12.2)], while four unaffected relatives had normal karyotypes. There is no evidence of Wilms tumor or genitourinary abnormalities in any members of the family. Restriction enzyme analysis of the human catalase gene revealed no abnormalities in the individuals with the translocation. A summary of phenotypic abnormalities in 61 cases associated with aniridia is presented, as well as a comparison of breakpoints in 44 cases of 11p deletion. These data indicate that single breaks at 11p13 are associated with isolated aniridia, while deletion of 11p13 results in aniridia combined with Wilms tumor, genitourinary abnormalities, and/or mental retardation.
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Erlich SS, McComb JG, Hyman S, Weiss MH. Ultrastructural morphology of the olfactory pathway for cerebrospinal fluid drainage in the rabbit. J Neurosurg 1986; 64:466-73. [PMID: 3950724 DOI: 10.3171/jns.1986.64.3.0466] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous physiological studies indicate that the olfactory region serves as a major pathway for cerebrospinal fluid (CSF) drainage into the lymphatic system. The present study was undertaken to determine the ultrastructural characteristics of this egress route. New Zealand White rabbits received a single bolus injection of the tracer ferritin (MW 400,000) into both lateral ventricles in such a manner as not to raise the intraventricular pressure above the normal level. The animals were sacrificed via intracardiac perfusion of fixative between less than 12 minutes and 4 hours following injection. The cribriform region was removed en bloc, decalcified, sectioned coronally, and prepared for light and electron microscopic examination. The arachnoid, dura, and periosteum surrounding the fila olfactoria passing through the cribriform plate merge together and form the perineurium, which consists of multiple layers of loosely overlapping cells with widely separated junctions and few vesicles. The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick. The subarachnoid space freely communicates with the perineural space surrounding each filament. No morphological barrier between the perineural space and the loose submucosal connective tissue was identified. Whether or not the perineurium was multi- or single-layered, ferritin was noted in abundance between the loosely overlapping perineural cells and in the submucosal connective tissue. The distribution of ferritin at 12 minutes was similar to that at 4 hours; however, the quantity of ferritin was increased at 4 hours. These results indicate that no significant barrier to CSF drainage is present at the rabbit cribriform region and that CSF reaches the submucosal region rapidly via open pathways.
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Witzig JS, Stuckey R, Hyman S, Marcel LJ. Volcanic themes in dreams. J Anal Psychol 1985; 30:361-77. [PMID: 2414263 DOI: 10.1111/j.1465-5922.1985.00361.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Shen JY, Kelly DE, Hyman S, McComb JG. Intraorbital cerebrospinal fluid outflow and the posterior uveal compartment of the hamster eye. Cell Tissue Res 1985; 240:77-87. [PMID: 3995547 DOI: 10.1007/bf00217560] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [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
An ultrastructural and tracer study was undertaken to determine normal outflow pathways of cerebrospinal fluid (CSF) at the terminal subarachnoid space (SAS) of the optic nerve. In the morphological studies, the optic nerve dura and arachnoid were found to be continuous with the sclera of the eye beyond the optic nerve SAS. The pia mater is continuous with the inner sclera and the lamina fusca of the eye. Montages and serial sections demonstrated that the distal SAS is divided into numerous tortuous channels to form an "arachnoidal trabecular meshwork". Spaces of this meshwork continue into "microcanals" which bypass the outer arachnoid barrier layers of the optic nerve meninges to reach the sclera and posterior intraorbital connective tissue. Ferritin infused into the cisterna magna entered the optic nerve SAS within 1 min and reached arachnoidal trabecular meshwork channels and the microcanals within 8 min. It then passed into intraorbital connective tissue spaces at the posterior pole of the eye. Ferritin appeared to be blocked by the lamina fusca and a newly discovered "posterior compact zone" which together prevented its entrance into the choroidal interstitium. These observations suggest that a "subarachnoidal-scleral-orbital outflow pathway" provides a route for CSF drainage from the optic nerve SAS to intraorbital connective tissue. The previously described "posterior uveal compartment" in the hamster eye (Kelly et al. 1983) appears to be relatively isolated from this subarachnoidal-scleral-orbital CSF outflow.
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Little FM, Gomer CJ, Hyman S, Apuzzo ML. Observations in studies of quantitative kinetics of tritium labelled hematoporphyrin derivatives (HpDI and HpDII) in the normal and neoplastic rat brain model. J Neurooncol 1984; 2:361-70. [PMID: 6241630 DOI: 10.1007/bf00178119] [Citation(s) in RCA: 28] [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: 01/19/2023]
Abstract
Increasing interest has developed in the use of the photodynamic agent, Hematoporphyrin derivative (HpD) for photoradiation therapy (PRT) as adjunctive therapy of malignant glial tumors of the brain. HpD, injected systemically, is preferentially taken up and retained by neoplastic tissue. Early studies of such uptake have largely relied on gross fluorescence as evidence of tissue uptake. In this study HpD was labelled with a tritiated radioisotope (3H) in order to quantify tissue uptake in visceral and in normal and neoplastic brain tissues in a rat brain model. 3H-HpD was injected intravenously at a 10 mg/kg dose into 30 Sprague-Dawley rats (Group A) without tumors in order to clarify method. Separately, 3H-HpD of like dosage was injected into 20 Fischer-344 rats (Group B), 5 control and 15 with a 9L gliosarcoma implanted in the left anterior cerebral cortex. Post injection sacrifice occurred at 6, 24 and 48 hours. From the Sprague-Dawley group multiple somatic and cerebral specimens were assayed. Differential areas within the brain showed no significant difference in uptake. The tumor area, peritumoral margin, and distant uninvolved areas of the Fischer-344 9L rats were likewise assayed. Definite uptake of normal visceral and cerebral tissue occurred with a markedly higher uptake differential in tumor areas. Such differential was relatively consistent from trial to trial, but multiple separate values obtained in the respective study groups were often unreliabe in their reproducibility and at variance with previously reported tissue level studies. These findings implied an instability of 3H-HpD, subsequently confirmed chromatographically as contamination probably due to time related degradation and exchange. Therefore, 3H-HpD appears to inherently carry such a risk for contamination. The compound Photofrin II (HpDII) represents a chromatographic fraction of HpD (HpDI), currently considered its most photodynamically active and purest component. Tritiated Photofrin II was used for quantification. An assay was performed with 5 Fischer-344 9L brain tumor rats (Group C), sacrificed at 24 hours. Photofrin II provided results more reliably reproducible. Contamination, degradation, and exchange of 3H-Photofrin II did not appear to occur. Neoplastic brain levels of the Photofrin II isotope were higher than in the HpD studies, and highly fluorescent. Normal brain values were consistently minimal and without fluorescence. The differential tumor/brain ratio in Photofrin II was consequently much higher. The isolated active substrate of HpDI and HpDII (Photofrin II) appears to be the compound DiHematoporphyrin Ether (DHE).(ABSTRACT TRUNCATED AT 400 WORDS)
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Giannotta SL, Hirtz SK, Hyman S. Effect of heparin reversal following endarterectomy in an atherosclerotic animal model. Bull Clin Neurosci 1984; 49:52-62. [PMID: 6546040] [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: 04/05/2023]
Abstract
A focal atherosclerotic plaque was induced in the aortas of New Zealand White female rabbits by a balloon injury and an atherogenic diet. Under general anesthesia and systemic heparinization, endarterectomy was performed using the operating microscope. Animals were sacrificed at 5, 10, 20, and 60 min following the endarterectomy and operated aortic segments were perfused and examined using scanning electron microscopy. Each segment was compared to a similar segment of endarterectomized aorta from a normal, nonatherosclerotic rabbit. Thrombus formation including aggregated platelets, red cells, and fibrin was found to be more pronounced in the atherosclerotic segments. Ten more atherosclerotic rabbits underwent identical procedures except that heparin was reversed using protamine sulfate 5 min following the endarterectomy. When these specimens were compared to a similar atherosclerotic group without heparin reversal, it was evident that a tremendous thrombogenic process had taken place in the "reversed" segments. This study suggests that atherosclerosis may alter thrombogenesis following an operative vascular procedure and that early reversal of heparin following an endarterectomy should be viewed with caution.
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