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Stieb DM, Smith‐Doiron M, Quick M, Christidis T, Xi G, Miles RM, van Donkelaar A, Martin RV, Hystad P, Tjepkema M. Inequality in the Distribution of Air Pollution Attributable Mortality Within Canadian Cities. Geohealth 2023; 7:e2023GH000816. [PMID: 37654974 PMCID: PMC10465848 DOI: 10.1029/2023gh000816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/14/2023] [Accepted: 07/20/2023] [Indexed: 09/02/2023]
Abstract
Recent studies have identified inequality in the distribution of air pollution attributable health impacts, but to our knowledge this has not been examined in Canadian cities. We evaluated the extent and sources of inequality in air pollution attributable mortality at the census tract (CT) level in seven of Canada's largest cities. We first regressed fine particulate matter (PM2.5) and nitrogen dioxide (NO2) attributable mortality against the neighborhood (CT) level prevalence of age 65 and older, low income, low educational attainment, and identification as an Indigenous (First Nations, Métis, Inuit) or Black person, accounting for spatial autocorrelation. We next examined the distribution of baseline mortality rates, PM2.5 and NO2 concentrations, and attributable mortality by neighborhood (CT) level prevalence of these characteristics, calculating the concentration index, Atkinson index, and Gini coefficient. Finally, we conducted a counterfactual analysis of the impact of reducing baseline mortality rates and air pollution concentrations on inequality in air pollution attributable mortality. Regression results indicated that CTs with a higher prevalence of low income and Indigenous identity had significantly higher air pollution attributable mortality. Concentration index, Atkinson index, and Gini coefficient values revealed different degrees of inequality among the cities. Counterfactual analysis indicated that inequality in air pollution attributable mortality tended to be driven more by baseline mortality inequalities than exposure inequalities. Reducing inequality in air pollution attributable mortality requires reducing disparities in both baseline mortality and air pollution exposure.
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Affiliation(s)
- David M. Stieb
- Environmental Health Science and Research BureauHealth CanadaVancouverBCCanada
- Environmental Health Science and Research BureauHealth CanadaOttawaONCanada
- School of Epidemiology and Public HealthUniversity of OttawaOttawaONCanada
| | - Marc Smith‐Doiron
- Environmental Health Science and Research BureauHealth CanadaOttawaONCanada
| | - Matthew Quick
- Health Analysis DivisionStatistics CanadaOttawaONCanada
| | | | - Guoliang Xi
- Environmental Health Science and Research BureauHealth CanadaOttawaONCanada
| | - Rosalin M. Miles
- Faculty of EducationIndigenous Health & Physical Activity ProgramUniversity of British ColumbiaVancouverBCCanada
- Physical Activity and Chronic Disease Prevention UnitFaculty of EducationUniversity of British ColumbiaVancouverBCCanada
- Indigenous Physical Activity and Cultural CircleVancouverBCCanada
| | - Aaron van Donkelaar
- Department of EnergyEnvironmental & Chemical EngineeringWashington UniversitySt. LouisMOUSA
| | - Randall V. Martin
- Department of EnergyEnvironmental & Chemical EngineeringWashington UniversitySt. LouisMOUSA
| | - Perry Hystad
- College of Public Health and Human SciencesOregon State UniversityCorvallisORUSA
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Wang X, Chen X, Kang X, Zhang R, Qu D, Xue L, Cheng G, Xi G, Zhang T, Deng L, Liu W, Bi N, Li Y. 92P Neoadjuvant multimodality RX including immunotherapy for highly selective unresectable locally advanced esophageal squamous cell carcinoma (NEXUS): A prospective, single-arm, phase II trial. Immuno-Oncology and Technology 2022. [DOI: 10.1016/j.iotech.2022.100196] [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: 12/13/2022]
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Kalapurakal J, Wang Y, Ghoreishi-Haack N, Wang W, Wang X, Xi G, Burdett K, Zhang H, Gopalakrishnan M, Mehta M, James C, Horbinski C. CDK 4/6 Inhibitors are Potent Radiosensitizers in Retinoblastoma Protein Positive Meningiomas. Int J Radiat Oncol Biol Phys 2022. [DOI: 10.1016/j.ijrobp.2022.07.450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Du Y, Fang Z, Jiao J, Xi G, Zhu C, Ren Y, Guo Y, Wang Y. Application of ultrasound-based radiomics technology in fetal-lung-texture analysis in pregnancies complicated by gestational diabetes and/or pre-eclampsia. Ultrasound Obstet Gynecol 2021; 57:804-812. [PMID: 32250510 DOI: 10.1002/uog.22037] [Citation(s) in RCA: 15] [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: 10/23/2019] [Revised: 03/06/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVES To analyze and compare, using ultrasound-based radiomics technology, fetal-lung texture in pregnancies affected by gestational diabetes mellitus (GDM) and/or pre-eclampsia (PE) and in normal pregnancies, overall and at different gestational ages. METHODS In this retrospective study, 430 high-throughput features per fetal-lung image were extracted from 548 fetal-lung ultrasound images (obtained at the level of the four-chamber view of the heart) in 548 pregnant women who delivered between July 2018 and August 2019 at the Obstetrics and Gynecology Hospital of Fudan University. Images had been obtained during ultrasound examinations between 28 and 41 weeks of gestation. The data were divided randomly into training set (80% of fetal-lung images) and independent test set (20% of images), and 20% of the images in the training set were then selected as the validation set. A standard machine-learning model based on ultrasound-based radiomics technology was created using features of fetal-lung texture extracted from the images, and a regression model was used to evaluate the relationship between lung-texture features, GDM and/or PE and gestational age. RESULTS Of the 548 pregnancies included, 108 were affected by GDM alone, 71 by PE alone and 25 by both GDM and PE, and 344 were normal. The overall performance of the GDM and PE prediction model was superior to that of the gestational-age prediction model, with an area under the receiver-operating-characteristics curve of 0.95-0.99, sensitivity of 78.8-97.1% in the validation set and 74.5-91.3% in the independent test set, specificity of 79.8-94.3% in the validation set and 75.7-88.4% in the independent test set and accuracy of 81.0-95.3% in the validation set and 80.6-86.4% in the independent test set. CONCLUSIONS Using ultrasound-based radiomics technology, fetal lungs from pregnancies grouped according to whether they were affected by GDM and/or PE could be distinguished from each other and from fetal lungs of normal pregnancies, and lungs from pregnancies at different gestational ages could be distinguished. These findings support further research to explore the use of this non-invasive technology to predict neonatal respiratory complications in women with PE, GDM or their combination. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- Y Du
- Department of Ultrasound, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Z Fang
- Department of Electronic Engineering, Fudan University, Shanghai, China
- Key Laboratory of Medical Imaging, Computing and Computer-Assisted Intervention, Shanghai, China
| | - J Jiao
- Department of Electronic Engineering, Fudan University, Shanghai, China
- Key Laboratory of Medical Imaging, Computing and Computer-Assisted Intervention, Shanghai, China
| | - G Xi
- Department of Ultrasound, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - C Zhu
- Department of Ultrasound, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Y Ren
- Department of Ultrasound, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Y Guo
- Department of Electronic Engineering, Fudan University, Shanghai, China
- Key Laboratory of Medical Imaging, Computing and Computer-Assisted Intervention, Shanghai, China
| | - Y Wang
- Department of Electronic Engineering, Fudan University, Shanghai, China
- Key Laboratory of Medical Imaging, Computing and Computer-Assisted Intervention, Shanghai, China
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Matz CJ, Egyed M, Xi G, Racine J, Pavlovic R, Rittmaster R, Henderson SB, Stieb DM. Health impact analysis of PM 2.5 from wildfire smoke in Canada (2013-2015, 2017-2018). Sci Total Environ 2020; 725:138506. [PMID: 32302851 DOI: 10.1016/j.scitotenv.2020.138506] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [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: 02/05/2020] [Revised: 04/02/2020] [Accepted: 04/04/2020] [Indexed: 05/24/2023]
Abstract
Smoke from wildfires contains many air pollutants of concern and epidemiological studies have identified associations between exposure to wildfire smoke PM2.5 and mortality and respiratory morbidity, and a possible association with cardiovascular morbidity. For this study, a retrospective analysis of air quality modelling was performed to quantify the exposure to wildfire-PM2.5 across the Canadian population. The model included wildfire emissions from across North America for a 5-month period from May to September (i.e. wildfire season), between 2013 and 2015 and 2017-2018. Large variations in wildfire-PM2.5 were noted year-to-year, geospatially, and within fire season. The model results were then used to estimate the national population health impacts attributable to wildfire-PM2.5 and the associated economic valuation. The analysis estimated annual premature mortalities ranging from 54-240 premature mortalities attributable to short-term exposure and 570-2500 premature mortalities attributable to long-term exposure, as well as many non-fatal cardiorespiratory health outcomes. The economic valuation of the population health impacts was estimated per year at $410M-$1.8B for acute health impacts and $4.3B-$19B for chronic health impacts for the study period. The health impacts were greatest in the provinces with populations in close proximity to wildfire activity, though health impacts were also noted across many provinces indicating the long-range transport of wildfire-PM2.5. Understanding the population health impacts of wildfire smoke is important as climate change is anticipated to increase wildfire activity in Canada and abroad.
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Affiliation(s)
- Carlyn J Matz
- Air Health Effects Assessment Division, Health Canada, 269 Laurier Ave W, PL 4903C, Ottawa, ON K1A 0K9, Canada.
| | - Marika Egyed
- Air Health Effects Assessment Division, Health Canada, 269 Laurier Ave W, PL 4903C, Ottawa, ON K1A 0K9, Canada.
| | - Guoliang Xi
- Population Studies Division, Health Canada, 101 Tunney's Pasture Dr., PL 0201A, Ottawa, ON K1A 0K9, Canada.
| | - Jacinthe Racine
- Canadian Meteorological Centre Operations, Environment and Climate Change Canada, 2121 Rte Transcanadienne, Montreal, QC H9P 1J3, Canada.
| | - Radenko Pavlovic
- Canadian Meteorological Centre Operations, Environment and Climate Change Canada, 2121 Rte Transcanadienne, Montreal, QC H9P 1J3, Canada.
| | - Robyn Rittmaster
- Economic Health and Analysis Division, Health Canada, 269 Laurier Ave W, PL 4904B, Ottawa, ON K1A 0K9, Canada.
| | - Sarah B Henderson
- Environmental Health Services, British Columbia Centre for Disease Control, 655 W 12th Ave, Vancouver, BC V5Z 4R4, Canada.
| | - David M Stieb
- Population Studies Division, Health Canada, 445-757 West Hasting St., Federal Tower, Vancouver, BC V6C 1A1, Canada.
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Maile LA, Busby WH, Xi G, Gollahan KP, Flowers W, Gafbacik N, Gafbacik S, Stewart K, Merricks EP, Nichols TC, Bellinger DA, Clemmons DR. An anti-αVβ3 antibody inhibits coronary artery atherosclerosis in diabetic pigs. Atherosclerosis 2017; 258:40-50. [PMID: 28189040 DOI: 10.1016/j.atherosclerosis.2017.01.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 01/19/2017] [Accepted: 01/25/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND AIMS Diabetes is a major risk factor for the development of atherosclerosis. Hyperglycemia stimulates vascular smooth muscle cells (VSMC) to secrete ligands that bind to the αVβ3 integrin, a receptor that regulates VSMC proliferation and migration. This study determined whether an antibody that had previously been shown to block αVβ3 activation and to inhibit VSMC proliferation and migration in vitro, inhibited the development of atherosclerosis in diabetic pigs. METHODS Twenty diabetic pigs were maintained on a high fat diet for 22 weeks. Ten received injections of anti-β3 F(ab)2 and ten received control F(ab)2 for 18 weeks. RESULTS The active antibody group showed reduction of atherosclerosis of 91 ± 9% in the left main, 71 ± 11%, in left anterior descending, 80 ± 10.2% in circumflex, and 76 ± 25% in right coronary artery, (p < 0.01 compared to lesions areas from corresponding control treated arteries). There were significant reductions in both cell number and extracellular matrix. Histologic analysis showed neointimal hyperplasia with macrophage infiltration, calcifications and cholesterol clefts. Antibody treatment significantly reduced number of macrophages contained within lesions, suggesting that this change contributed to the decrease in lesion cellularity. Analysis of the biochemical changes within the femoral arteries that received the active antibody showed a 46 ± 12% (p < 0.05) reduction in the tyrosine phosphorylation of the β3 subunit of αVβ3 and a 40 ± 14% (p < 0.05) reduction in MAP kinase activation. CONCLUSIONS Blocking ligand binding to the αVβ3 integrin inhibits its activation and attenuates increased VSMC proliferation that is induced by chronic hyperglycemia. These changes result in significant decreases in atherosclerotic lesion size in the coronary arteries. The results suggest that this approach may have efficacy in treating the proliferative phase of atherosclerosis in patients with diabetes.
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Affiliation(s)
- L A Maile
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - W H Busby
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - G Xi
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - K P Gollahan
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - W Flowers
- Department of Animal Science, NC State University, Raleigh, NC, USA
| | - N Gafbacik
- Department of Animal Science, NC State University, Raleigh, NC, USA
| | - S Gafbacik
- Department of Animal Science, NC State University, Raleigh, NC, USA
| | - K Stewart
- Department of Animal Science, NC State University, Raleigh, NC, USA
| | - E P Merricks
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - T C Nichols
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - D A Bellinger
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA
| | - D R Clemmons
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC, USA.
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Xi G, Hayes E, Lewis R, Ichi S, Mania-Farnell B, Shim K, Takao T, Allender E, Mayanil CS, Tomita T. Retraction Note: CD133 and DNA-PK regulate MDR1 via the PI3K- or Akt-NF-κB pathway in multidrug-resistant glioblastoma cells in vitro. Oncogene 2016; 35:5576. [DOI: 10.1038/onc.2016.64] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Saratsis A, Kambhampati M, Hall J, Stampar M, Xi G, Raabe E, Packer R, Nazarian J. BT-01 * TENASCIN-C: A NOVEL THERAPEUTIC TARGET IN PEDIATRIC BRAINSTEM GLIOMA. Neuro Oncol 2015. [DOI: 10.1093/neuonc/nov061.11] [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: 11/12/2022] Open
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Xi G, Hayes E, Lewis R, Ichi S, Mania-Farnell B, Shim K, Takao T, Allender E, Mayanil CS, Tomita T. CD133 and DNA-PK regulate MDR1 via the PI3K- or Akt-NF-κB pathway in multidrug-resistant glioblastoma cells in vitro. Oncogene 2015; 35:241-50. [PMID: 25823028 DOI: 10.1038/onc.2015.78] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 01/22/2015] [Accepted: 02/22/2015] [Indexed: 01/01/2023]
Abstract
Chemotherapy is an adjuvant treatment for glioblastomas, however, chemotherapy remains palliative because of the development of multidrug resistance (MDR). Following prolonged chemotherapy, MDR protein 1 (MDR1) and CD133 increase in recurrent glioblastomas. CD133 positive (CD133+) glioma cancer stem-like cells (GCSCs) markedly promote drug resistance and exhibit increased DNA damage repair capability; thus they have a key role in determining tumor chemosensitivity. Although CD133, DNA-dependent protein kinase (DNA-PK), and MDR1 are elevated in CD133+ GCSCs, the relationship among these molecules has not been elucidated. In this study, MDR glioblastoma cell lines were created in response to prolonged doxorubicin chemotherapy. CD133, DNA-PK and MDR1 were markedly elevated in these cells. CD133 and DNA-PK may increase MDR1 via the phosphatidylinositol-3-kinase (PI3K)-Akt signal pathway. PI3K downstream targets Akt and nuclear factor (NF)-κB, which interacts with the MDR1 promoter, were also elevated in these cells. Downregulation of CD133 and DNA-PK by small interfering RNA, or inhibition of PI3K or Akt, decreased Akt, NF-κB and MDR1 expression. The results indicate that CD133 and DNA-PK regulate MDR1 through the PI3K- or Akt-NF-κB signal pathway. Consequently, a novel chemotherapeutic regimen targeting CD133 and DNA-PK in combination with traditional protocols may increase chemotherapeutic efficacy and improve prognosis for individuals who present with glioblastoma.
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Affiliation(s)
- G Xi
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Falk Brain Tumor Center, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - E Hayes
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - R Lewis
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - S Ichi
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Development Biology Program, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - B Mania-Farnell
- Department of Biological Sciences, Purdue University Calumet, Hammond, IN, USA
| | - K Shim
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Development Biology Program, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - T Takao
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Development Biology Program, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - E Allender
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Development Biology Program, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - C S Mayanil
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Development Biology Program, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - T Tomita
- Division of Pediatric Neurosurgery, Stanley Manne Children's Research Institute, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Falk Brain Tumor Center, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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O'Brien SF, Goldman M, Scalia V, Yi QL, Fan W, Xi G, Dines IR, Fearon MA. The epidemiology of human T-cell lymphotropic virus types I and II in Canadian blood donors. Transfus Med 2013; 23:358-66. [PMID: 23859527 DOI: 10.1111/tme.12057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 06/11/2013] [Accepted: 06/16/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Blood donors in Canada have been tested for Human T-Cell Lymphotropic Virus (HTLV) since 1990. We report the epidemiology, risk factors and lookback/traceback of HTLV-positive donors/recipients. METHODS The annual HTLV rate was calculated from 1990 to 2010. Residual risk was estimated as the product of incidence and window period. Twenty-nine HTLV-positive donors and 116 matched controls (ratio 1 : 4) were interviewed about risk factors. For HTLV-positive donations, lookback investigations involved identification of all previous donations, and attempting to locate and test recipients. Traceback was initiated when transfusion transmission was queried for HTLV-positive blood recipients. All donors of products that the recipient received were identified, with an attempt to locate and test them. RESULTS The HTLV rate decreased from 9.35 per 100,000 donations in 1990 to 1.11 in 2010. The residual risk of infection was 1 in 7.6 million donations. In logistic regression birth overseas (OR 18.7), history of sexually transmitted diseases (OR 32.9), sex with unknown background (OR 5.4) and blood transfusion (OR 8.9) were significant predictors. In the lookback study, of 109 HTLV-positive donors, 508 components were transfused, of whom 147 recipients were tested and 18 (12%) were positive. All were transfused prior to the implementation of donor testing. Twenty-three traceback investigations were requested involving 324 transfused untested products,of whom 219 (67.6%) of donors were tested and 13 (6%) were positive for HTLV. CONCLUSIONS With testing of the blood supply, the risk from HTLV is very low and while most HTLV-positive donors have risk factors, deferrable risk is rare.
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Affiliation(s)
- S F O'Brien
- Canadian Blood Services, Ottawa, ON, Canada; Department of Epidemiology & Community Medicine
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Fan W, Yi QL, Xi G, Goldman M, Germain M, O'Brien S. The impact of increasing the upper age limit of donation on the eligible blood donor population in Canada. Transfus Med 2012; 22:395-403. [DOI: 10.1111/j.1365-3148.2012.01184.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/20/2012] [Accepted: 08/17/2012] [Indexed: 11/29/2022]
Affiliation(s)
- W. Fan
- Canadian Blood Services; Ottawa; ON; Canada
| | | | - G. Xi
- Public Health Agency of Canada
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Keep RF, Xi G, Hua Y, Xiang J. Clot formation, vascular repair and hematoma resolution after ICH, a coordinating role for thrombin? Acta Neurochir Suppl 2011; 111:71-5. [PMID: 21725734 DOI: 10.1007/978-3-7091-0693-8_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Following intracerebral hemorrhage (ICH) there is a sequential response involving activation of the coagulation cascade/platelet plug formation, vascular repair, upregulation of endogenous defense mechanisms and clot resolution. How these responses are coordinated and modified by different hematoma sizes has received little attention. This paper reviews evidence that thrombin can modulate and may coordinate the components of the endogenous response. This has potential consequences for treatment of ICH with a number of modalities.
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Affiliation(s)
- Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109-2200, USA.
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McDowell I, Xi G, Lindsay J, Tuokko H. Canadian Study of Health and Aging: Study Description and Patterns of Early Cognitive Decline. Aging, Neuropsychology, and Cognition 2010. [DOI: 10.1080/13825580490511044] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Ian McDowell
- a Department of Epidemiology and Community Medicine , University of Ottawa , Ont., Canada
| | - Guoliang Xi
- a Department of Epidemiology and Community Medicine , University of Ottawa , Ont., Canada
| | - Joan Lindsay
- a Department of Epidemiology and Community Medicine , University of Ottawa , Ont., Canada
| | - Holly Tuokko
- b Centre for Studies on Aging , University of Victoria , Ont., BC, Canada
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Wu J, Yang S, Hua Y, Liu W, Keep RF, Xi G. Minocycline attenuates brain edema, brain atrophy and neurological deficits after intracerebral hemorrhage. Acta Neurochir Suppl 2010; 106:147-50. [PMID: 19812938 DOI: 10.1007/978-3-211-98811-4_26] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Evidence suggests that microglia activation contributes to brain injury after intracerebral hemorrhage (ICH). The present study aimed to determine if minocycline, an inhibitor of microglia activation, can reduce brain edema, brain atrophy and neurological deficits after ICH.Male Sprague-Dawley rats received an infusion of 100-microL autologous whole blood into the right basal ganglia. Rats received minocycline or vehicle treatment. There were two sets of experiments in this study. In the first set of experiments, the effects of minocycline on ICH-induced brain edema were examined at day 3. In the second set, behavioral tests were performed at days 1, 3, 7, 14 and 28. Rats were killed at day 28 for brain atrophy measurement (caudate and lateral ventricle size).Minocycline reduced perihematomal brain edema in the ipsilateral basal ganglia (78.8 +/- 0.4 vs. 80.9 +/- 1.1% in the vehicle-treated group, p < 0.01). Minocycline also improved functional outcome. In addition, minocycline reduced brain tissue loss in the ipsilateral caudate (p < 0.01) and ventricular enlargement (p < 0.05).In conclusion, minocycline attenuates ICH-induced brain edema formation, neurological deficits and brain atrophy in rats suggesting an important role of microglia in ICH-related brain injury.
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Affiliation(s)
- J Wu
- R5018 Biomedical Science Research Building, Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109-2200, USA
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O'Brien SF, Xi G, Yi QL, Goldman M. Understanding non-disclosure of deferrable risk: a study of blood donors with a history of intravenous drug use. Transfus Med 2009; 20:15-21. [PMID: 19793079 DOI: 10.1111/j.1365-3148.2009.00969.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Non-disclosure of deferrable risk has received little attention in the literature. We examined deferrable risk (history of intravenous drug use [IVDU]) and donor attitudes towards truthfulness, the screening process and interpretation of the screening question as well as risk profile. Donors negative for all markers with a self-reported history of IVDU (N = 30) and matched controls were identified from an anonymous mail-out survey. In a separate survey, hepatitis C virus (HCV)-positive donors participated in a telephone interview, from which all those with IVDU history (N = 29) were selected plus matched controls (combined total 59 IVDU, 236 controls). IVDU donors, when compared with matched controls, tended to believe that it is OK not to answer truthfully if one believes that her/his blood is safe (18.6% vs. 4.7%) and that some questions are a little too personal (35.6% vs. 21.7%). IVDU donors were more likely than controls to say they failed to acknowledge screening questions appropriately (23% vs. 2.2%) or to agree that IVDU questions are mainly about recent drug taking or sharing needles (29% vs. 11%) even though the screening question asked about IVDU ever without any such qualifiers. IVDU donors were also more likely to have other lifestyle/risk factors such as history of sex with IVDU (45.5% vs. 1.7%). Donors with deferrable IVDU history may rationalise that revealing their status is not necessary and may misinterpret the question. Failure to acknowledge risk behaviour is complex, and some degree of non-disclosure may be an inherent part of pre-donation screening.
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Affiliation(s)
- S F O'Brien
- Canadian Blood Services, Ottawa, ON, Canada. sheila.o'
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18
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Abstract
BACKGROUND In the mid-1980s, confidential unit exclusion (CUE) was implemented to permit donors unwilling to admit risk factors in screening to exclude their donation from transfusion. With changes in donor behaviour, epidemiology of disease and improvements in testing, many blood establishments have stopped using it. We evaluated its benefit in Canada, and reported its utility in predicting transmissible-disease (TD) and high-risk behaviour. STUDY DESIGN AND METHODS TD-positive donations and incident cases between 2004 and 2008 were analyzed in CUE-safe and CUE-unsafe designated donations. An anonymous survey of 40,000 donors asked about CUE use and risk factors. RESULTS There were 7104 (0.15%) donations designated CUE-unsafe of 4,775,044 donations. Most TD-positive donations were designated CUE-safe (1023/1030, 99.32%) with only seven (0.68%) designated CUE-unsafe. Of 95 incident cases, all were designated CUE-safe including three NAT-yield cases (1 HIV and 2 HCV). In the survey, some donors found the CUE difficult to understand [10.5% (first-time), 3.2% (repeat)], only half thought that the blood would still be tested [48.9% (first-time), 45.9% (repeat)], and about a fifth believed that collection site staff could see their designation. No survey respondents who used the CUE admitted to risk behaviour, but about 1% of donors who designated CUE-safe had high-risk behaviours. CONCLUSION The data do not provide any indication of a safety benefit from CUE, but CUE use results in a small but constant loss of apparently safe donations.
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Affiliation(s)
- S F O'Brien
- Canadian Blood Services, Ottawa, ON, Canada. sheila.o'
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19
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Song S, Hua Y, Keep RF, He Y, Wang J, Wu J, Xi G. Deferoxamine reduces brain swelling in a rat model of hippocampal intracerebral hemorrhage. Cerebral Hemorrhage 2009; 105:13-8. [DOI: 10.1007/978-3-211-09469-3_3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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He Y, Hua Y, Song S, Liu W, Keep RF, Xi G. Induction of autophagy in rat hippocampus and cultured neurons by iron. Cerebral Hemorrhage 2009; 105:29-32. [DOI: 10.1007/978-3-211-09469-3_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Keep RF, Xiang J, Ennis SR, Andjelkovic A, Hua Y, Xi G, Hoff JT. Blood-brain barrier function in intracerebral hemorrhage. Acta Neurochir Suppl 2009; 105:73-7. [PMID: 19066086 DOI: 10.1007/978-3-211-09469-3_15] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
In this paper, we review current knowledge on blood-brain barrier (BBB) dysfunction following intracerebral hemorrhage (ICH). BBB disruption is a hallmark of ICH-induced brain injury. Such disruption contributes to edema formation, the influx of leukocytes, and the entry of potentially neuroactive agents into the perihematomal brain, all of which may contribute to brain injury. A range of factors have been implicated in inducing BBB disruption, including inflammatory mediators (e.g., cytokines and chemokines), thrombin, hemoglobin breakdown products, oxidative stress, complement, and matrix metalloproteinases. While there is interaction between some of these mediators, it is probable that prevention of ICH-induced BBB disruption will involve blocking multiple pathways or blocking a common end pathway (e.g., by stabilizing tight junction structure). While the effects of ICH on BBB passive permeability have been extensively examined, effects on other 'barrier' properties (metabolic and transport functions) have been less well-studied. However, recent data suggests that ICH can affect transport and that this may help protect the BBB and the brain. Indeed, it is possible in small bleeds that BBB disruption may be beneficial, and it is only in the presence of larger bleeds that disruption has detrimental effects.
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Affiliation(s)
- R F Keep
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
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22
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Wu J, Yang S, Xi G, Song S, Fu G, Keep RF, Hua Y. Microglial activation and brain injury after intracerebral hemorrhage. Acta Neurochir Suppl 2009; 105:59-65. [PMID: 19066084 DOI: 10.1007/978-3-211-09469-3_13] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microglial activation and thrombin formation contribute to brain injury after intracerebral hemorrhage (ICH). Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) are 2 major proinflammatory cytokines. In this study, we investigated whether thrombin stimulates TNF-alpha and IL-1beta secretion in vitro, and whether microglial inhibition reduces ICH-induced brain injury in vivo. There were 2 parts to this study. In the first part, cultured rat microglial cells were treated with vehicle, thrombin (5 and 10U/mL), or thrombin plus tuftsin (0.05 microg/mL), an inhibitor of microglia activation. Levels of TNF-alpha and IL-1beta in culture medium were measured by ELISA at 4, 8, and 24 h after thrombin treatment. In the second part of the study, rats received an intracerebral infusion of 100 microL autologous whole blood with or without 25 microg of tuftsin 1-3 fragment. Rats were killed at day 1 or day 3 for immunohistochemistry and brain water content measurement. We found that thrombin receptors were expressed in cultured microglia cells, and TNF-alpha and IL-1beta levels in the culture medium were increased after thrombin treatment. Tuftsin reduced thrombin-induced upregulation of TNF-alpha and IL-1beta. In vivo, microglia were activated after ICH, and intracerebral injection of tuftsin reduced brain edema in the ipsilateral basal ganglia (81.1 +/- 0.7% vs. 82.7 +/- 1.3% in vehicle-treated group; p < 0.05) after ICH. These results suggest a critical role of microglia activation in ICH-related brain injury.
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Affiliation(s)
- J Wu
- Medical School, Zhejiang University, Hangzhou, China
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23
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Abstract
BACKGROUND In August 2005, the Canadian Blood Services decreased the deferral period for tattooing and ear or body piercing from 12 to 6 months. This study assessed the impact of this change on blood safety and availability. STUDY DESIGN AND METHODS The prevalence of these activities was assessed on an anonymous mail-out survey of 40,000 recent donors. Transmissible disease (TD) marker rates were calculated using the National Epidemiology Donor Database. A case-control study was performed comparing risk factors in TD-positive donors with matched controls. Donor deferral rates were assessed before and after the change in deferral period. RESULTS The prevalence rates of tattoo, ear piercing, and body piercing were 13.7, 53.6, and 10.4 percent in survey respondents, respectively, with up to 0.7 percent of activity likely to represent deferrable risk. TD marker rate was low and stable at 21.6 per 100,000 donations before and 19.2 per 100,000 donations after the change in deferral length. Remote tattoo was associated with hepatitis C virus (HCV) risk (odds ratio, 5.43; 95% confidence interval, 1.82-16.2), but neither recent tattoo nor piercing was a risk factor for HCV or hepatitis B virus. Shortening of the deferral period reduced deferrals by 20 percent for tattoo and 32 percent for piercing. CONCLUSION There was no measurable adverse effect on safety and a positive but less than expected effect on blood availability after shortening the deferral period for tattoo and piercing. The length of other temporary deferrals should be reassessed, since their current contribution to blood safety may be negligible.
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Affiliation(s)
- Mindy Goldman
- Canadian Blood Services Donor and Transplantation Services, University of Ottawa, Ottawa, Ontario, Canada.
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24
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Abstract
BACKGROUND The residual risk of hepatitis B is higher than for other markers such as human immunodeficiency virus and hepatitis C virus in nonendemic countries. Evaluating the potential for further risk reduction requires a better understanding of the relationship between donor selection criteria, immigration from endemic countries, and public health vaccination strategies. STUDY DESIGN AND METHODS Age and sex trends of hepatitis B surface antigen (HBsAg)-positive donors from 1997 to 2006 were analyzed using a Poisson model. All HBsAg-positive donors in 2005/2006 plus four matched control donors for every HBsAg-positive donor who participated were invited to participate in a risk factor interview and predictors of HBsAg positivity identified by logistic regression. A survey of 40,000 donors who did not react for all markers asked about vaccination history and country of birth. RESULTS Most HBsAg-positive donations were from first-time donors (86%), have been decreasing in donors under the age of 30 (p < 0.01), and were correlated with geographic regions with more donors from higher-prevalence countries (p < 0001). Birth in a higher-prevalence country predicted HBsAg positivity (p < 0.01). Fifty-six percent of donors reported being vaccinated for hepatitis including approximately 80 percent of donors under age 30 who reported being vaccinated as part of regular school programs. CONCLUSION HBsAg-positive donations are decreasing in donors under age 30, those most frequently vaccinated through provincial vaccination programs. HBsAg-positive donations largely reflect immigration from high-prevalence countries without other deferrable risk factors, mainly chronic cases that will be detected by current testing. Furthermore, risk of incident infections should decrease with increasing vaccination rates in donors, especially the younger cohort now receiving universal vaccination.
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O'Brien SF, Chiavetta JA, Fan W, Xi G, Yi QL, Goldman M, Scalia V, Fearon MA. Assessment of a travel question to identify donors with risk of Trypanosoma cruzi: operational validity and field testing. Transfusion 2008; 48:755-61. [DOI: 10.1111/j.1537-2995.2007.01602.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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O'Brien SF, Fan W, Xi G, Yi QL, Goldman M, Fearon MA, Infante-Rivard C, Chiavetta JA, Willems B, Pi D, Fast M, Delage G. Declining hepatitis C rates in first-time blood donors: insight from surveillance and case-control risk factor studies. Transfusion 2008; 48:902-9. [PMID: 18208409 DOI: 10.1111/j.1537-2995.2007.01618.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Hepatitis C virus (HCV) rates have decreased steadily in first-time donors in Canada since testing was implemented but reasons are unclear. A description of factors that may have played a role in this decline is reported. STUDY DESIGN AND METHODS Descriptive analysis of first-time blood donors by HCV positivity status and year (1993--2006), sex, and age was carried out. HCV-positive first-time donors and matched controls participated in a confidential scripted telephone interview about risk factors in 1993 through 1994 and in 2005 through 2006, and risk factors independently predicting HCV positivity were determined with multiple logistic regression. RESULTS HCV-positive donations occurred most frequently in donors born between 1945 and 1964 and decreased in this birth cohort over time (p < 0.01). At present, most first-time donors (74%) are born after 1964. History of intravenous drug use, sex with an intravenous drug user, blood transfusion, and tattoo independently predicted (p < 0.01) HCV positivity in both periods (1993--1994 and 2005--2006). CONCLUSION Most HCV-positive donors were born between 1945 and 1964, and the decline in HCV rates is associated primarily with this birth cohort. The key risk factors predicting HCV positivity did not change over the 13 years of the study. With approximately two-thirds of HCV-positive Canadians in the general population having been tested for HCV, potential donors may be aware of their HCV status and be likely to self-defer. This, and an increasing proportion of first-time donors born after 1964, may contribute to declining HCV rates in first-time donors.
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Affiliation(s)
- Sheila F O'Brien
- National Epidemiology and Surveillance, Canadian Blood Services, Ottawa, Ontario, Canada. sheila.o'
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27
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Abstract
Acute brain edema formation contributes to brain injury after intracerebral hemorrhage (ICH). It has been reported that hyperbaric oxygen (HBO) is neuroprotective in cerebral ischemia, subarachnoid hemorrhage, and brain trauma. In this study, we investigated the effects of HBO on brain edema following ICH in rats. Male Sprague-Dawley rats received intracerebral infusion of autologous whole blood, thrombin, or ferrous iron. HBO (100% O2, 3.0 ATA for 1 h) was initiated 1 h after intracerebral injection. Control rats were exposed to air at room pressure. Brains were sampled at 24 or 72 h for water content, ion measurement, and Western blot analysis. We found that 1 session of HBO reduced perihematomal brain edema (p < 0.05) 24 h after ICH. HBO also reduced heat shock protein-32 (HSP-32) levels (p < 0.05) in ipsilateral basal ganglia 24h after ICH. However, HBO failed to attenuate thrombin-induced brain edema and exaggerated ferrous iron-induced brain edema (p < 0.05). Three sessions of HBO also failed to reduce brain edema 72h after ICH. In summary, HBO reduced early perihematomal brain edema and HSP-32 levels in brain. HBO-related brain protection does not occur through reduction in thrombin toxicity because HBO failed to attenuate thrombin-induced brain edema. Our results also indicate that HBO treatment after hematoma lysis for ICH may be harmful, since HBO amplifies iron-induced brain edema.
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Affiliation(s)
- Z Qin
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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Gong Y, Xi G, Wan S, Gu Y, Keep RF, Hua Y. Effects of aging on complement activation and neutrophil infiltration after intracerebral hemorrhage. Acta Neurochir Suppl 2008; 105:67-70. [PMID: 19066085 DOI: 10.1007/978-3-211-09469-3_14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Intracerebral hemorrhage (ICH)-induced brain edema and neurological deficits are greater in aged rats than in young rats. Complement activation and neutrophil infiltration contribute to brain injury after ICH. In this study, we investigated the effects of aging on activation of the complement cascade and neutrophil influx following ICH. Male Sprague-Dawley rats (3 or 18 months old) received an infusion of 100 microL autologous blood into right caudate. Rats were killed at 1, 3, 7, and 28 days after ICH and the brains were sampled for immunohistochemistry and Western blot analysis. Levels of complement factor C9 and clusterin were used as markers for complement activation, and myeloperoxidase (MPO) staining was performed to detect neutrophil infiltration. Western blot analysis showed that complement C9 and clusterin levels in ipsilateral basal ganglia after ICH were higher in aged rats than in young rats (p < 0.05). Immunohistochemistry showed there were more C9- and clusterin-positive cells around the hematoma in aged rats. However, MPO-positive cells in ipsilateral basal ganglia were fewer in aged rats (p < 0.05) after ICH. Our results suggest that ICH causes more severe complement activation and less neutrophil infiltration in aged rats. Clarification of the mechanisms of brain injury after ICH in the aging brain should help develop new therapeutic strategies for ICH.
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Affiliation(s)
- Y Gong
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI, USA 48109-2200, USA
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Kuroiwa T, Okauchi M, Hua Y, Schallert T, Keep RF, Xi G. Neurological deficits and brain edema after intracerebral hemorrhage in Mongolian gerbils. Acta Neurochir Suppl 2008; 105:127-130. [PMID: 19066097 DOI: 10.1007/978-3-211-09469-3_26] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We examined the time course of neurological deficits in gerbils after an intracerebral hemorrhage (ICH) induced by autologous blood infusion and examined its correlation with the severity of perihematomal edema. Mongolian gerbils (n = 15) were subjected to stereotaxic autologous blood infusion (30 or 60 microL) into the left caudate nucleus. Corner-turn and forelimb-placing tests were performed before, and 1 and 3 days after ICH. Perihematomal water content was measured by tissue gravimetry. Gerbils developed neurological deficits and perihematomal edema at day 1 after ICH. Both neurological deficits and perihematomal edema were significantly greater in animals with 60 microL blood infusion compared to the 30 microL infusion group, and both neurological deficits and edema were also greater at 3 days compared to 1 day after ICH. The severity of neurological deficits paralleled the degree of perihematomal edema. We conclude that the Mongolian gerbil is a suitable model for studies on the behavioral effects of ICH.
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Affiliation(s)
- T Kuroiwa
- Clinical Laboratory, Namegata District General Hospital, Namegata, Ibaraki, Japan.
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30
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O'Lynnger T, He Y, Hu H, Hua Y, Muraszko KM, Xi G. Concomitant intracerebral infusion of tissue plasminogen activator and thrombin leads to brain injury. Acta Neurochir Suppl 2008; 105:55-58. [PMID: 19066083 DOI: 10.1007/978-3-211-09469-3_12] [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: 05/27/2023]
Abstract
Low doses of thrombin are neuroprotective while high doses are neurotoxic and lead to brain injury. However, evidence suggests that low doses of thrombin cause brain injury when infused concomitantly with tissue plasminogen activator (tPA), which is used clinically to facilitate evacuation of intracerebral hematomas. In this study, we examined the effects of intracerebral infusion of tPA and thrombin, individually and in combination. Rats were infused in the right basal ganglia with 50 microL saline solutions containing thrombin, tPA, or thrombin + tPA. In the first experiment, rats were used for blood-brain barrier (BBB) permeability measurements at 24 h after infusion. In the second experiment, animals were euthanized 3 days after infusion, and brain sections were stained with Fluoro-Jade to measure neuronal cell death. Behavioral tests were carried out before and after surgery. Infusion of thrombin + tPA markedly increased Evans blue tissue content in ipsilateral brain samples (p < 0.05). Fluoro-Jade-stained sections from thrombin + tPA group demonstrated significantly higher cell death counts (p < 0.01). Significant neurological deficit was revealed in thrombin + tPA group in forelimb-placing and corner-turn tests (p < 0.01). This study shows that tPA potentiates the neurotoxic effects of thrombin and leads to increased BBB permeability, neuronal cell death, and neurological deficit. Our results suggest that using tPA to lyse intracerebral hematomas has potential to produce neuronal cell death and disruption of BBB.
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Affiliation(s)
- T O'Lynnger
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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Xi G, Hathaway MR, White ME, Dayton WR. Localization of insulin-like growth factor (IGFBP)-3 in cultured porcine embryonic myogenic cells before and after TGF-beta1 treatment. Domest Anim Endocrinol 2007; 33:422-9. [PMID: 17049199 DOI: 10.1016/j.domaniend.2006.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Revised: 07/18/2006] [Accepted: 08/18/2006] [Indexed: 01/10/2023]
Abstract
Insulin-like growth factor binding protein (IGFBP)-3 binds IGFs with high affinity and affects their biological activity. IGFBP-3 that is not bound to IGF also affects cells via mechanisms involving binding to specific cell surface receptors and/or transport into the cell. IGFBP-3 is produced by porcine embryonic myogenic cell (PEMC) cultures. Additionally, IGFBP-3 facilitates the proliferation-suppressing actions of TGF-beta(1) and myostatin in PEMC cultures via mechanisms that do not involve IGF binding. Moreover, these mechanisms do not involve preventing myostatin or TGF-beta(1)-induced increases in phosphosmad2 or phosphosmad3 level. Consequently, the mechanism(s) by which IGFBP-3 facilitates the proliferation-suppressing actions of TGF-beta(1) and myostatin in PEMC is unclear. Since IGFBP-3 reportedly interacts with nuclear proteins that regulate transcription, TGF-beta(1) or myostatin-induced translocation of IGFBP-3 into the nucleus may facilitate the proliferation-suppressing actions of these cytokines. Here, we show that IGFBP-3 is localized in cells containing the muscle specific protein desmin, thus establishing the presence of this IGFBP in myogenic cells. IGFBP-3 is present in the cytoplasm of all myogenic cells and approximately 50% of the nuclei of proliferating PEMC. IGFBP-3 is also detectable in fused myotubes. IGFBP-3 suppresses IGF-I-stimulated differentiation of PEMC but has no affect on Long-R3-IGF-I-stimulated differentiation of PEMC. Treatment of PEMC for 24h with TGF-beta(1) (20 ng/ml) results in a 78% (p<0.01) increase in the number of nuclei that contain detectable IGFBP-3. These results suggest that translocation of IGFBP-3 into the nucleus of PEMC could play a role in mediating the proliferation-suppressing action of TGF-beta(1).
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Affiliation(s)
- G Xi
- Animal Growth and Development Laboratory, Department of Animal Science, University of Minnesota, 348 Andrew Boss Laboratory, 1354 Eckles Avenue, St. Paul, MN 55108, USA
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Abstract
Explanations for the association between educational attainment and the risk of dementia fall into three main categories. It may arise as an artefact of study methods; education may predict broader socioeconomic circumstances and exposures, or education may reflect brain reserve or cognitive capacity that protect against dementia. Data from the Canadian Study of Health and Aging (N=6646, giving 44,676 person-years of follow-up) are analyzed to test a series of hypotheses reflecting these explanations. Years of education showed a strong association with the risk of dementia (relative risk [RR] 2.1 for those with less than 6 years of education compared to those with 13 or more years; RR=2.9 among survivors). Possible artefactual factors were detected, but were insufficient to invalidate the association. Adjustments for a range of other socioeconomic indicators, health problems and lifestyle factors reduced, but did not remove, the association. Adjustments for intelligence and for an indicator of lifetime mental activity also appeared to account for some but not all of the association. The conclusion is that there appears to be a real association between educational attainment and the risk of dementia 50 to 60 years later; this influence appears to run through a number of different, and sometimes complementary, pathways.
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Affiliation(s)
- Ian McDowell
- Department of Epidemiology & Community Medicine, University of Ottawa, Ontario, Canada.
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Xi G, Hathaway MR, Dayton WR, White ME. Growth factor messenger ribonucleic acid expression during differentiation of porcine embryonic myogenic cells. J Anim Sci 2007; 85:143-50. [PMID: 17179550 DOI: 10.2527/jas.2006-351] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The growth factors, IGF-I and II, their binding proteins, IGFBP, and members of the transforming growth factor (TGF) superfamily (myostatin and TGFbeta1) are known to regulate proliferation and differentiation of myogenic cells. We hypothesized that changes in the relative expression of members of the IGF and TGFbeta systems play a significant role in regulating myogenesis in porcine embryonic myogenic cell (PEMC) cultures. Therefore, determining the expression patterns of these factors during PEMC myogenesis is important. Consequently, we used real-time PCR to explore the pattern of IGF-I; IGF-II; IGFBP-2, -3, and -5; IGF-type-I receptor; myogenin; myostatin; and TGFbeta1 mRNA expression during PEMC myogenesis. The progression of differentiation was assessed using creatine kinase activity and myogenin mRNA expression. As anticipated, creatine kinase activity was low in PEMC cultures at 48 h and increased 20-fold (P < 0.0001) between 48 h and its peak at 144 h. Similarly, myogenin mRNA was low at 48 h and increased approximately 5-fold (P < 0.0001) as differentiation progressed, peaking at 120 h and decreasing at 144 h. The patterns of IGF-I and IGFBP-2 mRNA expression were similar and were relatively lower in 48-h PEMC cultures, increasing approximately 5-fold (P < 0.0001) to their greatest levels at 120 h. In contrast, IGF-II and IGFBP-5 mRNA levels were relatively high at 48 h, peaking at 72 h, and steadily decreasing by 60 and 80%, respectively (P < 0.001), at 144 h. The level of IGF-type-I receptor mRNA was relatively high until 96 h of culture, after which it decreased 40% (P < 0.01), reaching a low at 144 h. Levels of IGFBP-3 mRNA were relatively high at 48 h, dropped approximately 40% to their lowest level at 72 h (P < 0.001), and then increased approximately 60% (P < 0.001) to their greatest levels at 144 h. Levels of TGFbeta1 mRNA decreased approximately 30% (P < 0.0001) between 48 and 96 h, then quickly rebounded to a peak at 120 h, and by 144 h had dropped to the levels seen at 72 h. Myostatin mRNA was at its greatest level at 48 h and declined rapidly between 72 and 96 h, finally decreasing by approximately 80% at 144 h (P < 0.0001). Our data demonstrate that these factors are differentially regulated during PEMC myogenesis and provide new information about their pattern of mRNA expression in cultured porcine muscle cells.
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Affiliation(s)
- G Xi
- Animal Growth and Development Laboratory, Department of Animal Science, University of Minnesota, 350 ABLMS, 1354 Eckles Avenue, St. Paul 55108, USA
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Xi G, Kamanga-Sollo E, Hathaway MR, Dayton WR, White ME. Effect of constitutive expression of porcine IGFBP-3 on proliferation and differentiation of L6 myogenic cells. Domest Anim Endocrinol 2006; 31:35-51. [PMID: 16233971 DOI: 10.1016/j.domaniend.2005.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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] [Received: 07/28/2005] [Revised: 09/02/2005] [Accepted: 09/02/2005] [Indexed: 10/25/2022]
Abstract
We have previously shown that exogenous recombinant porcine IGFBP-3 (rpIGFBP-3) suppresses proliferation and differentiation of L6 myogenic cells in an IGF-I-dependent manner and suppresses proliferation of L6 myogenic cells via an IGF-I-independent mechanism. In order to assess the effects of endogenously produced IGFBP-3, we have transfected L6 myogenic cells with a pEF6/V5 vector containing pIGFBP-3 cDNA under the control of the human elongation factor 1alpha (hEF-1alpha) promoter and with the empty vector. We have isolated a cell population that constitutively produces porcine IGFBP-3 (tL6 cells) and a stable mock transfected cell population containing the empty vector (mtL6 cells). Constitutive expression of IGFBP-3 slightly reduced the expression of IGFBP-5 but had no effect on IGFBP-4 production by L6 myogenic cells. Immunoneutralization of IGFBP-3 increased both IGF-I- and Long-R3-IGF-I-stimulated proliferation of tL6 cells (58 and 33%, respectively) (P<0.01). These data indicate endogenous pIGFBP-3, like exogenous rpIGFBP-3, suppresses the proliferation of L6 myogenic cells via both IGF-I-dependent and -independent pathways. Immunoneutralization of IGFBP-3 also increased IGF-I-stimulated differentiation (21%, P<0.05) but had no effect on Long-R3-IGF-I stimulated differentiation of tL6 myogenic cells. Results indicate that exogenous and endogenous IGFBP-3 affect proliferation and differentiation of L6 myogenic cells in a similar way. Immunohistochemical localization data reveal that pre-incubation with anti-pIGFBP-3 dramatically reduces the level of intracellular IGFBP-3 in tL6 myogenic cells indicating that endogenously produced IGFBP-3 must first be secreted before it is internalized and that anti-pIGFBP-3 prevents internalization of IGFBP-3. TL6 and mtL6 cells provide a good system to further investigate the mechanisms by which IGFBP-3 affects proliferation and differentiation of myogenic cells.
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Affiliation(s)
- G Xi
- Animal Growth and Development Laboratory, Department of Animal Science, University of Minnesota, 348 ABLMS, Eckles Avenue, St. Paul, MN 55108, USA
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Abstract
Iron overload occurs in brain after intracerebral hemorrhage (ICH). Deferoxamine, an iron chelator, attenuates perihematomal edema and oxidative stress in brain after ICH. We investigated the effects of deferoxamine on cerebrospinal fluid (CSF) free iron and brain total iron following ICH. Rats received an infusion of 100-microL autologous whole blood into the right basal ganglia, then were treated with either deferoxamine (100 mg/kg, i.p., administered 2 hours after ICH and then at 12-hour intervals for up to 7 days) or vehicle. The rats were killed at different time points from 1 to 28 days for measurement of free and total iron. Behavioral tests were also performed. Free iron levels in normal rat CSF were very low (1.1 +/- 0.4 micromol). After ICH, CSF free iron levels were increased at all time points. Levels of brain total iron were also increased after ICH (p < 0.05). Deferoxamine given 2 hours after ICH reduced free iron in CSF at all time points. Deferoxamine also reduced ICH-induced neurological deficits (p < 0.05), but did not reduce total brain iron. In conclusion, CSF free iron levels increase after ICH and do not clear for at least 28 days. Deferoxamine reduces free iron levels and improves functional outcome in the rat, indicating that it may be a potential therapeutic agent for ICH patients.
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Affiliation(s)
- S Wan
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-0532, USA
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Nakamura T, Xi G, Keep RF, Wang M, Nagao S, Hoff JT, Hua Y. Effects of endogenous and exogenous estrogen on intracerebral hemorrhage-induced brain damage in rats. Acta Neurochir Suppl 2006; 96:218-21. [PMID: 16671458 DOI: 10.1007/3-211-30714-1_47] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The present study examined differences in intracerebral hemorrhage (ICH)-induced brain injury in male and female rats, whether delayed administration of 17beta-estradiol can reduce ICH-induced brain damage, and whether these effects are estrogen receptor (ER)-dependent. Male and female Sprague-Dawley rats received an infusion of 100-microL autologous whole blood into the right basal ganglia. The effects of 1beta-estradiol (5 mg/kg, i.p.) on ICH-induced brain injury were examined by measuring brain edema and neurological deficits 24 hours later. Heme oxygenase-1 (HO-1) was investigated by immuno-analysis. Brain edema was significantly less in female compared to male rats. The ER antagonist ICI182,780 exacerbated ICH-induced brain edema in female but not in male rats, suggesting that ER activation during ICH is protective in female rats. Administration of 17beta-estradiol to male (but not female) rats significantly reduced brain edema, neurological deficits, and ICH-induced increases in brain HO-1 levels when given 2 hours after ICH. This study showed that female rats have less ICH-induced injury than male rats. ER is involved in limiting ICH-induced injury in female rats. ICH-injury in male rats can be reduced by 17beta-estradiol. Since 17beta-estradiol treatment was effective in male rats, it could be a potential therapeutic agent for ICH.
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Affiliation(s)
- T Nakamura
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-0532, USA
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Gong Y, Tian H, Xi G, Keep RF, Hoff JT, Hua Y. Systemic zinc protoporphyrin administration reduces intracerebral hemorrhage-induced brain injury. Acta Neurochir Suppl 2006; 96:232-6. [PMID: 16671461 DOI: 10.1007/3-211-30714-1_50] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hemoglobin degradation products result in brain injury after intracerebral hemorrhage (ICH). Recent studies found that intracerebral infusion of heme oxygenase inhibitors reduces hemoglobin- and ICH-induced brain edema in rats and pigs. The present study examined whether systemic use of zinc protoporphyrin (ZnPP), a heme oxygenase inhibitor, can attenuate brain edema, behavioral deficits, and brain atrophy following ICH. All rats had intracerebral infusion of 100-microL autologous blood. ZnPP (1 nmol/hour/rat) or vehicle was given immediately or 6 hours following ICH. ZnPP was delivered intraperitoneally up to 14 days through an osmotic mini-pump. Rats were killed at day 3 and day 28 after ICH for brain edema and brain atrophy measurements, respectively. Behavioral tests were performed. We found that ZnPP attenuated brain edema in animals sacrificed 3 days after ICH (p < 0.05). ZnPP also reduced ICH-induced caudate atrophy (p < 0.05) and ventricular enlargement (p < 0.05). In addition, ZnPP given immediately or 6 hours after ICH improved neurological deficits (p < 0.05). In conclusion, systemic zinc protoporphyrin treatment started at 0 or 6 hours after ICH reduced brain edema, neurological deficits, and brain atrophy after ICH. These results indicate that heme oxygenase may be a new target for ICH therapeutics.
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Affiliation(s)
- Y Gong
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-0532, USA
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Abstract
Pretreatment with low-dose thrombin attenuates brain edema induced by iron or intracerebral hemorrhage (ICH). Ceruloplasmin is involved in iron metabolism by oxidizing ferrous iron to ferric iron. The present study examines whether thrombin modulates brain ceruloplasmin levels and whether exogenous ceruloplasmin reduces brain edema induced by ferrous iron in vivo. In the first set of experiments, rats received intracerebral infusion of saline or 1 U thrombin into the right basal ganglia. Rats were killed 1, 3, or 7 days later for Western blot analysis and RT-PCR analysis. In the second set of experiments, rats received either ferric iron, ferrous iron, or ferrous iron plus ceruloplasmin, then were killed 24 hours later for brain edema measurement. We found that ceruloplasmin protein levels in the ipsilateral basal ganglia increased on the first day after thrombin stimulation and peaked at day 3. Brain ceruloplasmin levels were higher after thrombin infusion than after saline injection. RT-PCR showed that brain ceruloplasmin mRNA levels were also up-regulated after thrombin injection (p < 0.05). We also found ipsilateral brain edema after intracerebral infusion of ferrous iron but not ferric iron at 24 hours. Co-injection of ferrous iron with ceruloplasmin reduced ferrous iron-induced brain edema (p < 0.05). Our results demonstrate that thrombin increases brain ceruloplasmin levels and exogenous ceruloplasmin reduces ferrous iron-induced brain edema, suggesting that ceruloplasmin up-regulation may contribute to thrombin-induced brain tolerance to ICH by limiting the injury caused by ferrous iron released from the hematoma.
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Affiliation(s)
- S Yang
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-0532, USA
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Hua Y, Keep RF, Muraszko KM, Hoff JT, Xi G. Reply to more on: the role of thrombin in gliomas. J Thromb Haemost 2006; 4:287. [PMID: 29322662 DOI: 10.1111/j.1538-7836.2005.01729.x] [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]
Affiliation(s)
- Y Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - R F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - K M Muraszko
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - J T Hoff
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - G Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
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Abstract
Recent case reports suggest that dopamine (DA) replacement may reduce behavioral deficits resulting from hemorrhages along the nigrostriatal tract. In the rat model of intracerebral hemorrhage (ICH), behavioral deficits are first evident on day 1, with return to near control levels by day 28. The current study was conducted to determine if striatal dopamine alterations are correlated with behavioral deficits. Gamma-aminobutyric acid (GABA) levels were measured to determine selectivity. Striatal DA, DA metabolites, and GABA were determined at days 1, 3, 7, and 28 after ICH by high-pressure liquid chromatography with electrochemical detection. ICH resulted in significant increases above control in DA contralateral to the lesion (177 to 361% above control, days 1 to 28). There were also significant, but much less marked changes in GABA. In the ipsilateral striatum, significant DA increases also occurred (approximately 200%, at day 3 and approximately 275% day 28), while GABA alterations were not significant. These results indicate that the striatal DA system is selectively altered after ICH. Further studies will be needed to determine if regional dopamine alterations occur relative to the location of the hematoma.
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Affiliation(s)
- J R Cannon
- Department of Environmental Health Sciences, University of Michigan Medical School, Ann Arbor, MI 48109-0532, USA
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Abstract
The complement cascade is activated and contributes to brain damage after intracerebral hemorrhage (ICH). The present study investigated ICH-induced brain damage in complement C3-deficient mice. This study was divided into 2 parts. Male C3-deficient and C3-sufficient mice received an infusion of 30-microl autologous whole blood into the right basal ganglia. In the first part of our study, mice were killed 3 days later for brain water content measurement. Behavioral assessments including forelimb use asymmetry and corner turn tests were also preformed before and after ICH. In the second part of the study, brain heme oxygenase-1 (HO-1) was measured by Western blot analysis and immunohistochemistry 3 days after the infusion. We found that brain water content in the ipsilateral basal ganglia 3 days after ICH was less in C3-deficient mice compared to C3-sufficient mice (p < 0.05). The C3-deficient mice had reduced ICH-induced forelimb use asymmetry deficits compared with C3-sufficient mice (p < 0.05), although there was no significant difference in the corner turn test score. Western blot analysis showed that HO-1 contents were significantly lower in C3-deficient mice (day 3: 2024 +/- 560 vs. 5140 +/- 1151 pixels in the C3-sufficient mice, p < 0.05). We conclude that ICH causes less brain edema and behavioral deficits in complement C3-deficient mice. These results suggest that complement C3 is a key factor contributing to brain injury following ICH.
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Affiliation(s)
- S Yang
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-0532, USA
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Nakamura T, Keep RF, Hua Y, Nagao S, Hoff JT, Xi G. Iron-induced oxidative brain injury after experimental intracerebral hemorrhage. Acta Neurochir Suppl 2006; 96:194-8. [PMID: 16671453 DOI: 10.1007/3-211-30714-1_42] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We investigated the occurrence of DNA damage in brain after intracerebral hemorrhage (ICH) and the role of iron in such injury. Male Sprague-Dawley rats received an infusion of 100 microL autologous whole blood or 30 microL FeCl2 into the right basal ganglia and were sacrificed 1, 3, or 7 days later. 8-hydroxyl-2'-deoxyguanosine (8-OHdG) was analyzed by immunohistochemistry, while the number of apurinic/apyrimidinic abasic sites (AP sites) was also quantified. 8-OHdG and AP sites are two hallmarks of DNA oxidation. DNA damage was also examined using PANT and TUNEL labeling. Dinitrophenyl (DNP) was measured by Western blot to compare the time course of protein oxidative damage to that of DNA. DNA repair APE/Ref-1 and Ku-proteins were also measured by Western blot. Bipyridine, a ferrous iron chelator, was used to examine the role of iron in ICH-induced oxidative brain injury. An increase in 8-OHdG, AP sites, and DNP levels, and a decrease in APE/Ref-1 and Ku levels were observed. Abundant PANT-positive cells were also observed in the perihematomal area 3 days after ICH. Bipyridine attenuated ICH-induced changes in PANT and DNP. These results suggest that iron-induced oxidation causes DNA damage in brain after ICH and that iron is a therapeutic target for ICH.
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Affiliation(s)
- T Nakamura
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan 48109-0532, USA
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Abstract
Early hematoma enlargement and delayed clot lysis contribute to brain injury after intracerebral hemorrhage (ICH). We investigated hematoma growth, clot lysis, and brain edema formation in patients with spontaneous ICH. A total of 17 spontaneous ICH patients who received regular medication were chosen for this study. All patients had their first CT scan within 5 hours of onset of symptoms (day 0). The patients then underwent second, third, and fourth CT scans at 1, 3, and 10 days later. Hematoma size and absolute and relative brain edema volumes were measured. Hematoma enlargement was defined as a > 33% increase in volume. Relative brain edema volume = absolute brain edema volume/hematoma size. Hematoma enlargement occurred in 4 of the 17 ICH patients (24%) within the first 24 hours. The hematoma sizes were reduced significantly at day 10 (p < 0.05) because of clot lysis. However, both absolute and relative brain edema increased gradually with time (p < 0.01). These results suggest that delayed brain edema following ICH may result from hematoma lysis. This study also shows that early hematoma enlargement occurs in Chinese patients with ICH. Reducing early hematoma growth and limiting clot lysis-induced brain toxicity could be potential therapies for ICH.
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Affiliation(s)
- G Wu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
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Shao J, Xi G, Hua Y, Schallert T, Felt BT. Alterations in intracerebral hemorrhage-induced brain injury in the iron deficient rat. Acta Neurochir Suppl 2006; 96:183-7. [PMID: 16671451 DOI: 10.1007/3-211-30714-1_40] [Citation(s) in RCA: 1] [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: 05/09/2023]
Abstract
BACKGROUND Iron contributes to brain edema and cellular toxicity after intracerebral hemorrhage (ICH). Knowledge regarding ICH in the context of iron deficiency anemia (IDA), a common nutritional disorder, is limited. OBJECTIVE To determine the effect of IDA on brain and behavioral outcome after ICH in rats. METHODS Six-week-old male rats (n = 75) were randomized to non-IDA or IDA groups. After 1 month of iron sufficient or deficient diets, 100 microl autologous blood was infused into the right basal ganglia (BG). Brains were assessed for iron concentration, regional water content, BG transferrin, and transferrin receptor concentrations after ICH. Recovery of upper extremity sensorimotor function was assessed. Brain and behavioral variables were compared by diet group. Significance was set at p < 0.05. RESULTS Whole brain iron was decreased and water content was increased for IDA rats in injured cortex and BG at day 3 (p < 0.05) compared with non-IDA rats. Transferrin and transferrin receptor content were increased in injured BG for IDA compared to non-IDA in the first week after ICH (p < 0.05). IDA rats had greater left vibrissae-stimulated forelimb-placing deficits and forelimb-use asymmetry than non-IDA after ICH (p < 0.05). CONCLUSIONS Brain iron status may be an important determinant of injury severity and recovery after ICH.
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Affiliation(s)
- J Shao
- Department of Pediatrics, Children's Hospital, Zhejiang University, China
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Abstract
BACKGROUND In a previous study we found that intracerebral infusion of argatroban, a specific thrombin inhibitor, reduces brain edema and neurologic deficits in a C6 glioma model. OBJECTIVES To examine the role of thrombin in gliomas and whether systemic argatroban administration can reduce glioma mass and neurologic deficits and extend survival time in C6 and F98 gliomas. METHODS The presence of thrombin in human glioblastoma samples and rat C6 glioma cells (in vitro and in vivo) was assessed using immunohistochemistry. The effect of thrombin on C6 cell proliferation in vitro was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. The role of thrombin in vivo was assessed in rat C6 and F98 glioma cell models using argatroban, a thrombin inhibitor. The effects of argatroban on tumor mass, neurologic deficits and survival time were investigated. RESULTS Thrombin immunoreactivity was found in cultured rat C6 glioma cells and human glioblastomas. Thrombin induced C6 cell proliferation in vitro. In C6 glioma, argatroban reduced glioma mass (P < 0.05) and neurologic deficits (P < 0.05) at day 9. In F98 glioma, argatroban prolonged survival time (P < 0.05). CONCLUSION These results suggest that thrombin plays an important role in glioma growth. Thrombin may be a new therapeutic target for gliomas.
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Affiliation(s)
- Y Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
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Abstract
OBJECTIVE To examine the association of income inequality at the public health unit level with individual health status in Ontario. METHODS Cross-sectional multilevel study carried out among subjects aged 25 years or older residing in 42 public health units in Ontario. Individual-level data drawn from 30,939 respondents in 1996-97 Ontario Health Survey. Median area income and income inequality (Gini coefficient) calculated from 1996 census. Self-rated health status (SRH) and Health Utilities Index (HUI-3) scores were used as main outcomes. RESULTS Controlling for individual-level factors including income, respondents living in public health units in the highest tercile of income inequality had odds ratios of 1.20 (95% CI 1.04 - 1.38) for fair/poor self-rated health, and 1.11 (95% CI 1.01 - 1.22) for HUI score below the median, compared with people living in public health units in the lowest tercile. Controlling further for median area income had little effect on the association. CONCLUSION Income inequality was significantly associated with individual self-reported health status at public health unit level in Ontario, independent of individual income.
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Affiliation(s)
- Guoliang Xi
- Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON.
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Pampusch MS, Xi G, Kamanga-Sollo E, Loseth KJ, Hathaway MR, Dayton WR, White ME. Production of recombinant porcine IGF-binding protein-5 and its effect on proliferation of porcine embryonic myoblast cultures in the presence and absence of IGF-I and Long-R3-IGF-I. J Endocrinol 2005; 185:197-206. [PMID: 15817840 DOI: 10.1677/joe.1.06037] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
IGF-binding protein-5 (IGFBP-5) is produced by porcine embryonic myogenic cell (PEMC) cultures and is secreted into the medium. IGFBP-5 may play some role in myogenesis and/or in changes in myogenic cell proliferation that accompany differentiation. IGFBP-5 reportedly may either suppress or stimulate proliferation or differentiation of cultured cells depending on cell type and culture conditions. Additionally, IGFBP-5 has been shown to possess both IGF-dependent and IGF-independent actions in some cell types. The goal of this study was to produce recombinant porcine IGFBP-5 (rpIGFBP-5) and assess its IGF-I-dependent and IGF-I-independent actions on the proliferation of PEMCs. To accomplish this, we have expressed porcine IGFBP-5 in the baculovirus system, purified and characterized the expressed rpIGFBP-5 and produced an anti-porcine IGFBP-5 antibody that neutralizes the biological activity of porcine IGFBP-5. rpIGFBP-5, purified to 98% homogeneity using nickel affinity chromatography and IGF-I affinity chromatography, suppressed IGF-I-stimulated proliferation of PEMCs in a concentration-dependent manner (P>0.05). rpIGFBP-5 also suppressed Long-R3-IGF-I-stimulated proliferation of PEMCs (P>0.05), even in the presence of significant molar excess of Long-R3-IGF-I compared with rpIGFBP-5, demonstrating the IGF-independent activity that rpIGFBP-5 possesses in PEMCs, since Long-R3-IGF-I is an IGF analog that has very low affinity for the IGFBPs but retains its ability to bind to the type I IGF receptor and thereby can stimulate proliferation. The anti-rpIGFBP-5 IgY produced against rpIGFBP-5 specifically recognized native porcine IGFBP-5 in PEMC media that also contained porcine IGFBP-2, -3, and -4. This antibody is capable of neutralizing the effects of both rpIGFBP-5 and endogenously produced porcine IGFBP-5 on PEMCs as well as detecting IGFBP-5 in Western blots. The production of rpIGFBP-5 and a neutralizing antibody to porcine IGFBP-5 provides a powerful tool to investigate the role of IGFBP-5 in porcine myogenic cell proliferation and differentiation. The data provided here demonstrated that IGFBP-5 has the potential to affect proliferation of PEMCs during critical periods of in vitro muscle cell development and therefore may impact the capacity for ultimate postnatal muscle mass development in vivo.
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Affiliation(s)
- M S Pampusch
- Animal Growth and Development Laboratory, Department of Animal Science, University of Minnesota, St Paul, Minnesota 55108, USA
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Kamanga-Sollo E, Pampusch MS, Xi G, White ME, Hathaway MR, Dayton WR. IGF-I mRNA levels in bovine satellite cell cultures: effects of fusion and anabolic steroid treatment. J Cell Physiol 2004; 201:181-9. [PMID: 15334653 DOI: 10.1002/jcp.20000] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Androgenic and estrogenic steroids enhance muscle growth in a number of species; however, the mechanism by which anabolic steroids enhance muscle growth is not known. Castrated male cattle (steers) provide a particularly good model system in which to study the effects of anabolic steroids on muscle growth because they respond dramatically to treatment with both estrogens and androgens. The goal of this study was to determine if treatment of bovine satellite cell (BSC) cultures with 17beta-estradiol (E(2)) or trenbolone (a synthetic androgen) directly affects proliferation rate or level of mRNA for estrogen receptor (ER)-alpha, androgen receptor, and growth factors that have been shown to affect muscle growth (insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3, and myostatin). BSC cultures were established from the semimembranosus muscles of steers and then treated for 48 h with various concentrations of E(2) or trenbolone ranging from 0.001 to 10 nM. IGF-I mRNA levels in proliferating BSC cultures were significantly increased at 0.01 (1.9-times control values, P < 0.02) and at 0.1, 1, and 10 nM E(2) (2.9-, 3.5-, and 3.5-times control values, respectively, P < 0.0001). Additionally both 1 and 10 nM trenbolone increased IGF-I mRNA levels to 1.7-times control values (P < 0.02). ER-alpha mRNA was detectable in BSC cultures, and levels were increased (2.3-times control levels, P < 0.001) in cultures treated with 0.001 nM E(2) but not in cultures treated with higher concentrations of E(2). Androgen receptor mRNA levels also were increased (1.5-times control levels, P < 0.02) in cultures treated with 0.001 nM trenbolone but not by treatment with higher concentrations of trenbolone. Levels of IGFBP-3 were increased (1.4-times control values, P < 0.02) by treatment with 0.001 nM E(2) but not by treatment with high concentrations of E(2). Myostatin mRNA levels were not affected by any concentration of either of the steroids. Although, levels of IGF-I mRNA were 10-times greater (P < 0.02) in fused BSC cultures than in proliferating cultures, treatment of fused cultures for 48 h with 10 nM E(2) increased IGF-I mRNA levels (2.5-times control levels, P < 0.02). Both E(2) and trenbolone increased (3)H-thymidine incorporation rate (1.5-times control levels, P < 0.001) in BSC cultures in media containing serum from which IGFBP-3 had been removed by anti-IGFBP-3 affinity chromatography. In summary, treatment of BSC cultures with either E(2) or trenbolone increased IGF-I mRNA level and proliferation rate, thus, establishing that these steroids have direct anabolic effects on cells present in the BSC culture.
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Affiliation(s)
- E Kamanga-Sollo
- Department of Animal Science, University of Minnesota, St. Paul, Minnesota 55108, USA
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Xi G, Kamanga-Sollo E, Pampusch MS, White ME, Hathaway MR, Dayton WR. Effect of recombinant porcine IGFBP-3 on IGF-I and long-R3-IGF-I-stimulated proliferation and differentiation of L6 myogenic cells. J Cell Physiol 2004; 200:387-94. [PMID: 15254966 DOI: 10.1002/jcp.20068] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Insulin-like growth factor (IGF)-I stimulates both proliferation and differentiation of myogenic precursor cells. In vivo, IGFs are bound to one of the members of a family of six high-affinity IGF binding proteins (IGFBP 1-6) that regulate their biological activity. One of these binding proteins, IGFBP-3, affects cell proliferation via both IGF-dependent and IGF-independent mechanisms and it has generally been shown to suppress proliferation of cultured cells; however, it also may stimulate proliferation depending upon the cell type and the assay conditions. Cultured porcine embryonic myogenic cells (PEMCs) produce IGFBP-3 and its level drops significantly immediately prior to differentiation. Additionally, IGFBP-3 suppresses both IGF-I and Long-R3-IGF-I-stimulated proliferation of embryonic porcine myogenic cells. In this study, we have examined the effects of recombinant porcine IGFBP-3 (rpIGFBP-3) on IGF-I- and Long-R3-IGF-I-stimulated proliferation and differentiation of the L6 myogenic cell line. L6 cells potentially provide a good model for studying the actions of IGFBP-3 on muscle because they contain no non-muscle cells and they do not produce detectable levels of IGFBP-3. RpIGFBP-3 suppresses both IGF-I and Long-R3-IGF-I-stimulated proliferation of L6 cells, indicating that it suppresses proliferation via both IGF-dependent and IGF-independent mechanisms. Our data also show that rpIGFBP-3 causes IGF-independent suppression of proliferation without increasing the level of phosphosmad-2 in L6 cultures. Additionally, rpIGFBP-3 suppresses IGF-I-stimulated differentiation of L6 cells. In contrast, however, rpIGFBP-3 does not suppress Long-R3-IGF-I-stimulated differentiation. This suggests that rpIGFBP-3 does not have IGF-independent effects on L6 cell differentiation.
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Affiliation(s)
- G Xi
- Department of Animal Science, University of Minnesota, St. Paul, Minnesota, 55108, USA
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Masada T, Hua Y, Xi G, Yang GY, Hoff JT, Keep RF, Nagao S. Overexpression of interleukin-1 receptor antagonist reduces brain edema induced by intracerebral hemorrhage and thrombin. Acta Neurochir Suppl 2004; 86:463-7. [PMID: 14753487 DOI: 10.1007/978-3-7091-0651-8_95] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Recent studies indicate that inflammatory reaction occurs around hematoma after intracerebral hemorrhage (ICH). In this study the authors examine the hypothesis that overexpression of IL-1ra in the brain attenuate brain edema formation after ICH. Adenoviruses expressing IL-1ra (Ad.RSVIL-1ra) or LacZ (Ad.RSVLacZ) or saline were injected into the lateral ventricle. On the fifth day after virus injection, 100 microl of autologous blood or 5 U thrombin was infused into the right basal ganglia. Rats with ICH were killed 24 or 72 hours later for measurement of brain water content. Thrombin-treated rats were killed 24 hours later for edema measurements and an assessment of polymorphonuclear leukocyte (PMNL) infiltration by myeloperoxidase (MPO) assay. Compared with control groups, Ad.RSVIL-1ra treated rats had less brain edema formation in the ipsilateral basal ganglia 3 days after ICH (81.5 +/- 0.3% compared with 83.4 +/- 0.4% and 83.3 +/- 0.5% in control animals). Ad.RSVIL-1ra treated rats had also less brain edema following thrombin injection. The reduction of brain edema induced by thrombin was involved in the reduction of PMNL infiltration in basal ganglia, as assessed by MPO assay. Adenovirus-mediated overexpression of IL-1ra attenuated brain edema formation following ICH, perhaps by reduction of thrombin-induced brain inflammation.
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Affiliation(s)
- T Masada
- Department of Neurological Surgery, Kagawa Medical University, Japan.
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