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Becker SL, Humphrey DC, Karriker LA, Brown JT, Skoland KJ, Greiner LL. The effects of dietary essential fatty acid ratios and linoleic acid level in grow-finish pigs. J Anim Sci 2023; 101:skad263. [PMID: 37540487 PMCID: PMC10449407 DOI: 10.1093/jas/skad263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/02/2023] [Indexed: 08/05/2023] Open
Abstract
The objective of this study was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (LA:ALA) on the growth performance, expression of genes associated with lipid metabolism, and inflammatory status of grow-finish pigs. A total of 300 growing pigs (body weight [BW] = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) dietary linoleic acid level with a high (23:1; HR), moderate (13:1; MR) or low (4:1; LR) dietary LA:ALA in a 2 × 3 factorial design. Diets were fed across three 28-d phases and were balanced for dietary metabolizable energy. Pigs were housed five pigs per pen in single-sex pens. Blood samples were collected on days 0, 21, 42, and 84, and synovial fluid was collected from the hock joint on days 0 and 84 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial BW as a covariate, pen as the experimental unit, and LA level, LA:ALA, sex, phases, and their interactions as fixed effects. Compared to HLA, LLA pigs tended to have increased BW at days 56 and 84 (P = 0.088). There was no effect of LA × LA:ALA for growth performance. For the overall days 0 to 84 growth period, pigs fed HR had increased ADG compared to MR, with pigs receiving LR performing intermediate of MR and HR. Gilts receiving HR diets had increased day 84 BW compared to gilts receiving the low and moderate LA:ALA (P = 0.006), which was a result of improved overall days 0 to 84 ADG compared to gilts receiving the MR diets (P = 0.023). Barrows fed LR had improved BW on day 56 compared to MR and HR and higher final BW compared to HR, with MR performing intermediately (P = 0.006). This was a result of greater days 0 to 84 ADG (P = 0.023). Overall, C-reactive protein (CRP), tumor necrosis factor-α (TNFα), and interleukin-6 were reduced in the plasma of pigs over time (P ≤ 0.037). Across all treatments, CRP and TNFα were reduced in the hock and carpus synovial fluid on day 84 vs. day 0 (P ≤ 0.049). In conclusion, LA:ALA ratios utilized in this study can be fed at varying linoleic acid levels without impacting growth or inflammation. Additionally, LA:ALA ratios can differentially impact the growth of gilts and barrows.
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Affiliation(s)
- Spenser L Becker
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Dalton C Humphrey
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Locke A Karriker
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Justin T Brown
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Kristin J Skoland
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Laura L Greiner
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
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2
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Becker SL, Humphrey DC, Karriker LA, Brown JT, Skoland KJ, Greiner LL. The effects of dietary essential fatty acid ratios and energy level on growth performance, lipid metabolism, and inflammation in grow-finish pigs. J Anim Sci 2023; 101:skad151. [PMID: 37170903 PMCID: PMC10226270 DOI: 10.1093/jas/skad151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/09/2023] [Indexed: 05/13/2023] Open
Abstract
The objective of this study was to investigate the effects of dietary metabolizable energy (ME) level and the ratio of linoleic acid:α-linolenic acid (LA:ALA) on the growth performance, lipid metabolism, circulatory and joint inflammatory status, and synovial fluid proteome of grow-finish pigs. A total of 224 pigs (BW = 41.5 ± 6.1 kg; PIC Genus 337 × 1050, Hendersonville, TN) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) ME dietary treatment with a high (23:1) or low (12:1) LA:ALA in a 2 × 2 factorial arrangement. Diets were fed across three 28-d phases. Pigs were housed either four barrows or four gilts per pen. Blood samples were collected on days 0, 21, 42, and 84. Synovial fluid was collected from the hock and carpus joints on days 0 and 84. Liver and adipose tissue samples were collected on day 84. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with pen as the experimental unit and energy level, essential fatty acid ratio, sex, phase, and their interactions as fixed effects. Compared to LE, HE increased days 28, 56, and 84 body weight (BW; P = 0.005). For the overall period, HE increased average daily gain (ADG) compared to LE (P < 0.001) and improved feed efficiency (P = 0.001), while LE increased feed intake compared to HE (P < 0.001). Gilts receiving diets with low LA:ALA had similar final BW to barrows receiving a low LA:ALA at days 28, 56, and 84 (P = 0.024), resulting from improved overall days 0-84 ADG compared to gilts receiving the high LA:ALA (P = 0.031). In the liver, HE decreased the mRNA abundance of acetyl CoA carboxylase (ACACA; P = 0.004), cluster of differentiation 36 (P = 0.034), and tended to decrease fatty acid synthase (FASN; P = 0.056). In adipose tissue, HE decreased ACACA (P = 0.001) and FASN (P = 0.017). Plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor-α (TNFα) were reduced on day 84 compared to day 0 (P ≤ 0.014). In the hock and carpus synovial fluid, LE tended to reduce CRP and TNFα (P ≤ 0.096). Hock and carpus synovial fluid CRP were also reduced on day 84 compared to day 0 (P = 0.001). Age of the pig impacted serum and hock synovial fluid protein abundance, but not energy level, LA:ALA, or their interactions (P < 0.05). To conclude, the high and low LA:ALA ratios utilized in this study can be fed at varying energy levels without impacting growth. Additionally, LA:ALA ratios can differentially impact the growth of barrows and gilts.
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Affiliation(s)
- Spenser L Becker
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Dalton C Humphrey
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Locke A Karriker
- Department of Veterinary Diagnostic and Production Medicine, Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Justin T Brown
- Department of Veterinary Diagnostic and Production Medicine, Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Kristin J Skoland
- Department of Veterinary Diagnostic and Production Medicine, Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Laura L Greiner
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
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3
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Ramirez BC, Jeon R, Stender DR, Kohl KD, Rademacher CJ, Brown JT, Mogler D. Characterization of in-barn heat processed swine mortalities. Front Vet Sci 2023; 10:929160. [PMID: 37020981 PMCID: PMC10067902 DOI: 10.3389/fvets.2023.929160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 02/27/2023] [Indexed: 04/07/2023] Open
Abstract
In-barn heat processing of mass swine mortalities to inactivate pathogens could facilitate more carcass disposal options and reduce the risk of pathogen spread in the event of a foreign animal disease (FAD) outbreak. A 12.2 × 12.2 × 2.4 m (W × L × H) heat processing room was created using a temporary wall inside a de-commissioned commercial gestation barn in northwest Iowa. Eighteen swine carcasses (six per group) divided into three weight groups (mean ± SD initial carcass weights: 31.8 ± 3.3, 102.7 ± 8.1, and 226.3 ± 27.6 kg) were randomly assigned a location inside the room. Three carcasses per weight group were placed directly on concrete slats and on a raised platform. One carcass per weight group and placement (n=6) was instrumented with five temperature sensors, inserted into the brain, pleura, peritoneal, ham, and bone marrow of the femur, and a sensor was attached directly to the skin surface. Environmental conditions (ambient and room) and carcass temperatures were collected at 15-min intervals. Carcasses were subjected to an average room temperature of 57.3 ± 1.2°C for 14 days. The average (±SD) reduction from initial weight for the carcasses on slats was 45.0 ± 4.70% (feeder), 33.0 ± 8.30% (market), and 34.0 ± 15.80% (sow), and for the carcasses on a raised platform, it was 39.0 ± 6.80% (feeder), 49.0 ± 11.30% (market), and 45.0 ± 6.70% (sow). There was a significant interaction between carcass placement (slats and raised) and carcass weight loss for the market weight group. When average carcass surface temperature was at 40.6, 43.3, and 46.1°C (data grouped for analysis), the average internal carcass temperature for most measurement locations was significantly different across carcass weight groups and between the carcasses on a raised platform and those on slats. This preliminary analysis of carcass weight loss, leachate production, and temperature variation in carcasses of different sizes can be used for planning and evaluating mass swine mortality management strategies.
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Affiliation(s)
- Brett C. Ramirez
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
- *Correspondence: Brett C. Ramirez
| | - Ryan Jeon
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Dave R. Stender
- Extension and Outreach, Iowa State University, Ames, IA, United States
| | - Kris D. Kohl
- Extension and Outreach, Iowa State University, Ames, IA, United States
| | - Chris J. Rademacher
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
| | - Justin T. Brown
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States
| | - Dwight Mogler
- Mogler Farms/Pig Hill Co., Lester, IA, United States
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Patterson G, Brown JT, Almond GW, Ramirez A, Pittman J, Pieters M, Bowman AS, Karriker LA, Zhitnitskiy PE. Challenges and opportunities in modern swine veterinary education. J Am Vet Med Assoc 2022; 260:711-713. [PMID: 35239507 DOI: 10.2460/javma.21.10.0443] [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: 11/20/2022]
Affiliation(s)
- Gilbert Patterson
- Lincoln Memorial University, College of Veterinary Medicine, Harrogate, TN
| | - Justin T Brown
- Iowa State University, College of Veterinary Medicine, Ames, IA
| | - Glen W Almond
- North Carolina State University, College of Veterinary Medicine, Raleigh, NC
| | - Alejandro Ramirez
- University of Arizona, College of Veterinary Medicine, Oro Valley, AZ
| | | | - Maria Pieters
- University of Minnesota, College of Veterinary Medicine, Saint Paul, MN
| | - Andrew S Bowman
- The Ohio State University, College of Veterinary Medicine, Columbus, OH
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D'Angelo AB, Davis Ewart LN, Koken J, Bimbi D, Brown JT, Grov C. Barriers and Facilitators to Pre-exposure Prophylaxis Uptake Among Black Women: A Qualitative Analysis Guided by a Socioecological Model. J Assoc Nurses AIDS Care 2021; 32:481-494. [PMID: 34171885 DOI: 10.1097/jnc.0000000000000241] [Citation(s) in RCA: 2] [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: 11/26/2022]
Abstract
ABSTRACT Black women experience disparities in HIV incidence. Pre-exposure prophylaxis (PrEP) is a once-daily pill that can prevent HIV transmission. To enhance PrEP uptake among Black women, it is essential to examine their perceptions of PrEP. In 2018, 33 Black women in New York City completed interviews about their attitudes, knowledge, and perceived barriers and facilitators to PrEP use. Emergent themes were organized using a socioecological model. Participants identified barriers at the sociocultural level, including stigma, medical mistrust, and health care avoidance. At the community level, health care access issues and limited community knowledge were reported. Partner-level barriers included trust in partners and meaning attributed to PrEP use within the context of monogamy. Individual-level barriers included low perceived risk and concerns about PrEP's safety and efficacy. Our findings can inform future PrEP research with Black women, as well as PrEP implementation efforts aimed at increasing uptake among this population.
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Affiliation(s)
- Alexa B D'Angelo
- Alexa B. D'Angelo, MPH, is a Project Coordinator and PhD Student, CUNY Institute for Implementation Science in Population Health, Graduate School of Public Health and Health Policy, New York, New York, USA. Leah N. Davis Ewart, MPH, CHES, is a PhD Student, Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, Florida, USA. Juline Koken, PhD, is an Associate Professor, Department of Health Sciences, LaGuardia Community College of CUNY, Long Island City, New York, USA. David Bimbi, PhD, is a Professor, Department of Health Sciences, LaGuardia Community College of CUNY, Long Island City, New York, USA. Justin T. Brown, PhD, MPH, is an Assistant Professor and Executive Director, Department of Health Sciences, The Center for LGBTQ Studies (CLAGS), LaGuardia Community College of CUNY, Long Island City, New York, USA. Christian Grov, PhD, MPH, is a Professor, Department of Community Health and Social Sciences, CUNY Graduate School of Public Health and Health Policy, New York, New York, USA
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6
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Ruston CR, Brown JT, Canning PE, Monahan VL, Fitzgerald CJQ, Skoland KJ, Kittrell H, Hayman K, Karriker LA. Development and Improvement of an International Webcast Series to Expand the Accessibility of Swine Medicine Resources. J Vet Med Educ 2021; 48:21-26. [PMID: 32412373 DOI: 10.3138/jvme.2019-0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Swine medicine resources and caseloads for teaching and supporting extracurricular training activities vary widely among veterinary colleges and are concentrated in specific regions. Student interest and demand for swine medicine training is broader in geographical distribution. This is illustrated by student membership and attendance at the American Association of Swine Veterinarians (AASV) annual meetings, for example. To explore how concentrated resources might be made more widely available in a cost-effective manner, the Swine Medicine Education Center (SMEC) at Iowa State University's College of Veterinary Medicine looked for ways to leverage existing extracurricular resources with a broader geography of schools and students. This article describes the organization of student chapters of the AASV and the outcomes of a multi-session live audio and video webcast focused on swine medicine topics across North America over a 3-year period. SMEC organized the series with funding provided by the AASV and AASV Foundation. The broadcast series covered a wide range of swine-related topics, including pet pigs, emerging diseases, and regulation of antimicrobials. In its third year, 25 North American and 4 international veterinary schools participated in the series and provided feedback from attendees.
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7
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Kittrell HC, Mochel JP, Brown JT, Forseth AMK, Hayman KP, Rajewski SM, Coetzee JF, Schneider BK, Ratliffe B, Skoland KJ, Karriker LA. Pharmacokinetics of Intravenous, Intramuscular, Oral, and Transdermal Administration of Flunixin Meglumine in Pre-wean Piglets. Front Vet Sci 2020; 7:586. [PMID: 33005646 PMCID: PMC7485418 DOI: 10.3389/fvets.2020.00586] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/21/2020] [Indexed: 11/29/2022] Open
Abstract
Castration and tail-docking of pre-wean piglets are common procedures that are known to induce pain and would benefit from pain mitigation. Flunixin meglumine (FM) is a non-steroidal anti-inflammatory drug currently approved in the United States for pyrexia in swine and lameness pain in cattle. The objective of this study was to establish the pharmacokinetic (PK) parameters resulting from intravenous (IV), intramuscular (IM), oral (PO) and transdermal (TD) administration of FM in pre-wean piglets. FM was administered to thirty-nine pre-wean piglets at a target dose of 2.2 mg/kg for IV and IM and 3.3 mg/kg for PO and TD route. Plasma was collected at twenty-seven time points from 0 to 9 days after FM administration and concentrations were determined using ultra-high performance liquid chromatography coupled with mass spectrometry (UPLC-MS). Pharmacokinetic data were analyzed using noncompartmental analysis (NCA) methods and nonlinear mixed-effects (NLME). Initial plasma concentration for IV (C0) 11,653 μg/L and mean peak plasma concentrations (Cmax) 6,543 μg/L (IM), 4,883 μg/L (PO), and 31.5 μg/L (TD) were measured. The time points of peak FM concentrations (tmax) were estimated 30 min, 1 h, and 24 h for IM, PO, and TD, respectively. The bioavailability (F) of PO and IM FM was estimated at >99%, while the bioavailability of TD FM was estimated to be 7.8%. The reported Cmax of FM after IM and PO administration is consistent with therapeutic concentration ranges that mitigate pain in other species and adult pigs. However, the low estimated concentration of FM after TD dosing is not expected to mitigate pain in pre-wean piglets. The low F of TD FM suggests that expanding the surface area of application is unlikely to be sufficient to establish an effective TD dose for pain, while the high bioavailability for PO FM should allow for an effective dose regimen to be established.
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Affiliation(s)
- Heather C Kittrell
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Jonathan P Mochel
- SMART Pharmacology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Justin T Brown
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Anna Marie K Forseth
- Animal Health Division, Montana Department of Livestock, Helena, MT, United States
| | - Kristen P Hayman
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Suzanne M Rajewski
- Analytical Chemistry Services, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Johann F Coetzee
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Benjamin K Schneider
- SMART Pharmacology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Brette Ratliffe
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Kristin J Skoland
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Locke A Karriker
- Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
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8
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Brown JT, Beldorth IJ, Laosinchai-Wolf W, Fahey ME, Jefferson KL, Ruskin AK, Roth JJ, Cai L, Watt CD, Press RD, Yang F, Hedges JB, Andruss BF. Analytical Validation of a Highly Sensitive, Multiplexed Chronic Myeloid Leukemia Monitoring System Targeting BCR-ABL1 RNA. J Mol Diagn 2019; 21:718-733. [PMID: 31026597 PMCID: PMC6626993 DOI: 10.1016/j.jmoldx.2019.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 03/08/2019] [Accepted: 03/20/2019] [Indexed: 01/01/2023] Open
Abstract
This study describes the analytical performance of the QuantideX qPCR BCR-ABL IS Kit, the first Food and Drug Administration–cleared assay designed to monitor breakpoint cluster region–Abelson tyrosine-protein kinase 1 (BCR-ABL1) fusion transcripts isolated from peripheral blood specimens from patients with chronic myeloid leukemia. This multiplex real-time quantitative RT-PCR assay amplifies both e13a2 and e14a2 Major BCR-ABL1 transcripts and the reference target ABL1. The test results are provided in international scale (IS) values by incorporating armored RNA-based calibrators that have defined IS values tied directly to the World Health Organization BCR-ABL1 Primary Reference Materials, without the necessity of determining and maintaining conversion factors. For each batch run, the integrated interpretive software evaluates run and specimen quality control metrics (including a sufficient amount of ABL1 control transcripts to ensure a minimal limit of detection) and calculates both molecular response (MR) and %IS values for each specimen. The test has a limit of detection of MR4.7 (0.002%IS) and a linear range from MR0.3 (50%IS) to MR4.7 (0.002%IS) for both Major transcripts. Single-site and multisite precision studies demonstrated a maximum SD of 0.13 MR (30% CV within the assay range between MR0.7 and MR3.7). The performance of this BCR-ABL1 monitoring test meets all of the clinical guideline recommendations for sensitivity and IS reporting for the management of chronic myeloid leukemia patients.
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Affiliation(s)
| | | | | | | | | | | | - Jacquelyn J Roth
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Li Cai
- Center for Molecular Biology and Pathology, Laboratory Corporation of America Holdings, Research Triangle Park, North Carolina
| | - Christopher D Watt
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Richard D Press
- Department of Pathology and Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon
| | - Fei Yang
- Department of Pathology and Knight Cancer Institute, Oregon Health and Science University, Portland, Oregon
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9
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Poonsuk K, Giménez-Lirola LG, Magtoto RL, Ji J, Baum DH, Rademacher CJ, Brown JT, Zhang J, Wang C, Main RG, Zimmerman JJ. The effect of chemical clarification of oral fluids on porcine epidemic diarrhea virus antibody responses. J Vet Diagn Invest 2018; 30:937-941. [PMID: 30204059 DOI: 10.1177/1040638718798672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Routine testing of breeding herd oral fluid (OF) samples for porcine epidemic diarrhea virus (PEDV) IgG and/or IgA is used to track levels of PEDV immunity over time. However, OFs contain particles of feed, feces, and inorganic material that detract from the quality of the sample. We clarified swine OF samples using lyophilized chitosan-based formulas (A-C) tested by PEDV IgG and IgA ELISAs. To evaluate both the immediate and residual effects of treatment on antibody detection, samples were tested immediately post-treatment, then stored at 4°C and retested at 2, 4, and 6 days post-treatment (DPT). Formulations were shown to effectively clarify samples. Statistical analysis comparing treated to untreated OF samples at 0 DPT found that neither chitosan nor Tween 20 affected the OF ELISA IgA and IgG sample-to-positive (S/P) ratio results ( p > 0.05). Furthermore, pairwise comparisons of 0 DPT to 2, 4, and 6 DPT results detected no significant differences ( p > 0.05) in IgA and IgG S/P ratios (i.e., treated OF samples were stable over time). Therefore, chitosan efficiently clarified OF specimens without affecting the results of the PEDV IgG and IgA antibody ELISAs.
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Affiliation(s)
- Korakrit Poonsuk
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Luis G Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Ronaldo L Magtoto
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Ju Ji
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - David H Baum
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Christopher J Rademacher
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Justin T Brown
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Chong Wang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Rodger G Main
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Jeffrey J Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
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10
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Brown JT, Abdel-Rahman SM, van Haandel L, Gaedigk A, Lin YS, Leeder JS. Single dose, CYP2D6 genotype-stratified pharmacokinetic study of atomoxetine in children with ADHD. Clin Pharmacol Ther 2016; 99:642-50. [PMID: 26660002 DOI: 10.1002/cpt.319] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 01/22/2023]
Abstract
The effect of CYP2D6 genotype on the dose-exposure relationship for atomoxetine has not been well characterized in children. Children 6-17 years of age diagnosed with attention-deficit hyperactivity disorder (ADHD) were stratified by CYP2D6 genotype into groups with 0 (poor metabolizers [PMs], n = 4), 0.5 (intermediate metabolizers [IMs], n = 3), one (extensive metabolizer [EM]1, n = 8) or two (EM2, n = 8) functional alleles and administered a single 0.5 mg/kg oral dose of atomoxetine (ATX). Plasma and urine samples were collected for 24 (IM, EM1, and EM2) or 72 hours (PMs). Dose-corrected ATX systemic exposure (area under the curve [AUC]0-∞ ) varied 29.6-fold across the study cohort, ranging from 4.4 ± 2.7 μM*h in EM2s to 5.8 ± 1.7 μM*h, 16.3 ± 2.9 μM*h, and 50.2 ± 7.3 μM*h in EM1s, IMs, and PMs, respectively (P < 0.0001). Simulated steady state profiles at the maximum US Food and Drug Administration (FDA)-recommended dose suggest that most patients are unlikely to attain adequate ATX exposures. These data support the need for individualized dosing strategies for more effective use of the medication.
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Affiliation(s)
- J T Brown
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota College of Pharmacy, Duluth, Minnesota, USA
| | - S M Abdel-Rahman
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - L van Haandel
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - A Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Y S Lin
- Department of Pharmaceutics, University of Washington School of Pharmacy, Seattle, Washington, USA
| | - J S Leeder
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
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11
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Witton J, Padmashri R, Zinyuk LE, Popov VI, Kraev I, Line SJ, Jensen TP, Tedoldi A, Cummings DM, Tybulewicz VLJ, Fisher EMC, Bannerman DM, Randall AD, Brown JT, Edwards FA, Rusakov DA, Stewart MG, Jones MW. Hippocampal circuit dysfunction in the Tc1 mouse model of Down syndrome. Nat Neurosci 2015; 18:1291-1298. [PMID: 26237367 PMCID: PMC4552261 DOI: 10.1038/nn.4072] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 06/29/2015] [Indexed: 12/11/2022]
Abstract
Hippocampal pathology is likely to contribute to cognitive disability in Down syndrome, yet the neural network basis of this pathology and its contributions to different facets of cognitive impairment remain unclear. Here we report dysfunctional connectivity between dentate gyrus and CA3 networks in the transchromosomic Tc1 mouse model of Down syndrome, demonstrating that ultrastructural abnormalities and impaired short-term plasticity at dentate gyrus-CA3 excitatory synapses culminate in impaired coding of new spatial information in CA3 and CA1 and disrupted behavior in vivo. These results highlight the vulnerability of dentate gyrus-CA3 networks to aberrant human chromosome 21 gene expression and delineate hippocampal circuit abnormalities likely to contribute to distinct cognitive phenotypes in Down syndrome.
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Affiliation(s)
- J Witton
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - R Padmashri
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - L E Zinyuk
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - V I Popov
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Reg. 142290, Russia.,The Open University, Department of Life Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - I Kraev
- The Open University, Department of Life Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - S J Line
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK
| | - T P Jensen
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - A Tedoldi
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - D M Cummings
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - V L J Tybulewicz
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - E M C Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - D M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK
| | - A D Randall
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - J T Brown
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - F A Edwards
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - D A Rusakov
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.,Laboratory of Brain Microcircuits, Institute of Biology and Biomedicine, University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
| | - M G Stewart
- The Open University, Department of Life Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - M W Jones
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
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12
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Brown JT, Wicklund BM, Abdel-Rahman SM. Individualized factor IX dosing in two brothers: application of longitudinal pharmacokinetic modelling to optimize therapeutic benefit. Haemophilia 2014; 21:e125-e127. [PMID: 25420419 DOI: 10.1111/hae.12593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2014] [Indexed: 11/25/2022]
Affiliation(s)
- J T Brown
- Division of Clinical Pharmacology and Therapeutic Innovation, Children's Mercy Hospitals and Clinics, Kansas, Missouri, USA
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13
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Kerrigan TL, Brown JT, Randall AD. Characterization of altered intrinsic excitability in hippocampal CA1 pyramidal cells of the Aβ-overproducing PDAPP mouse. Neuropharmacology 2014; 79:515-24. [PMID: 24055500 PMCID: PMC3989024 DOI: 10.1016/j.neuropharm.2013.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/21/2013] [Accepted: 09/04/2013] [Indexed: 11/27/2022]
Abstract
Transgenic mice that accumulate Aβ peptides in the CNS are commonly used to interrogate functional consequences of Alzheimer's disease-associated amyloidopathy. In addition to changes to synaptic function, there is also growing evidence that changes to intrinsic excitability of neurones can arise in these models of amyloidopathy. Furthermore, some of these alterations to intrinsic properties may occur relatively early within the age-related progression of experimental amyloidopathy. Here we report a detailed comparison between the intrinsic excitability properties of hippocampal CA1 pyramidal neurones in wild-type (WT) and PDAPP mice. The latter is a well-established model of Aβ accumulation which expresses human APP harbouring the Indiana (V717F) mutation. At the age employed in this study (9-10 months) CNS Abeta was elevated in PDAPP mice but significant plaque pathology was absent. PDAPP mice exhibited no differences in subthreshold intrinsic properties including resting potential, input resistance, membrane time constant and sag. When CA1 cells of PDAPP mice were given depolarizing stimuli of various amplitudes they initially fired at a higher frequency than WT cells. Commensurate with this, PDAPP cells exhibited a larger fast afterdepolarizing potential. PDAPP mice had narrower spikes but action potential threshold, rate of rise and peak were not different. Thus not all changes seen in our previous studies of amyloidopathy models were present in PDAPP mice; however, narrower spikes, larger ADPs and the propensity to fire at higher frequencies were consistent with our prior work and thus may represent robust, cross-model, indices of amyloidopathy. This article is part of a Special Issue entitled 'Neurodevelopment Disorder'.
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Affiliation(s)
- T L Kerrigan
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - J T Brown
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, The Hatherly Building, Exeter EX4 4PS, UK
| | - A D Randall
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, The Hatherly Building, Exeter EX4 4PS, UK.
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14
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Abstract
Array-based methods are making substantial contributions to the discovery of disease biomarkers and are fueling the growth of multianalyte testing for disease diagnosis and treatment. The distillation of high-density array results into sets of signature markers promises to improve disease staging, risk stratification and treatment decisions. To accommodate the growing requirement for multiplex testing, clinical laboratories are converting several single-analyte tests into array-based formats. However, adoption of array technologies provides several challenges to the laboratory, which must evaluate these new formats, train laboratory personnel, market the new services and obtain reimbursement for new analytes. Liquid-bead arrays are an attractive format for routine clinical diagnostics due to a combination of appropriate analyte density, simultaneous array decoding and detection, and flexibility for rapid customization. In this review, the suitability of several array platforms to diagnostic testing and applications of liquid-bead arrays for cystic fibrosis testing, multidisease carrier status assays and leukemia subtyping are discussed. As our understanding of the clinical utility of new or established biomarkers and recommendations for testing change, flexibility and adaptability of array platforms will be imperative. Future development of novel assay formats and improved quantitation will expand the number of diseases tested and lead to further integration into the diagnostic laboratory.
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Affiliation(s)
- Andrew G Hadd
- Ambion Diagnostics, 2130 Woodward Street, Austin, TX 78744, USA.
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15
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Cottrell CE, Al-Kateb H, Bredemeyer AJ, Duncavage EJ, Spencer DH, Abel HJ, Lockwood CM, Hagemann IS, O'Guin SM, Burcea LC, Sawyer CS, Oschwald DM, Stratman JL, Sher DA, Johnson MR, Brown JT, Cliften PF, George B, McIntosh LD, Shrivastava S, Nguyen TT, Payton JE, Watson MA, Crosby SD, Head RD, Mitra RD, Nagarajan R, Kulkarni S, Seibert K, Virgin HW, Milbrandt J, Pfeifer JD. Validation of a next-generation sequencing assay for clinical molecular oncology. J Mol Diagn 2013; 16:89-105. [PMID: 24211365 DOI: 10.1016/j.jmoldx.2013.10.002] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 08/23/2013] [Accepted: 10/01/2013] [Indexed: 11/29/2022] Open
Abstract
Currently, oncology testing includes molecular studies and cytogenetic analysis to detect genetic aberrations of clinical significance. Next-generation sequencing (NGS) allows rapid analysis of multiple genes for clinically actionable somatic variants. The WUCaMP assay uses targeted capture for NGS analysis of 25 cancer-associated genes to detect mutations at actionable loci. We present clinical validation of the assay and a detailed framework for design and validation of similar clinical assays. Deep sequencing of 78 tumor specimens (≥ 1000× average unique coverage across the capture region) achieved high sensitivity for detecting somatic variants at low allele fraction (AF). Validation revealed sensitivities and specificities of 100% for detection of single-nucleotide variants (SNVs) within coding regions, compared with SNP array sequence data (95% CI = 83.4-100.0 for sensitivity and 94.2-100.0 for specificity) or whole-genome sequencing (95% CI = 89.1-100.0 for sensitivity and 99.9-100.0 for specificity) of HapMap samples. Sensitivity for detecting variants at an observed 10% AF was 100% (95% CI = 93.2-100.0) in HapMap mixes. Analysis of 15 masked specimens harboring clinically reported variants yielded concordant calls for 13/13 variants at AF of ≥ 15%. The WUCaMP assay is a robust and sensitive method to detect somatic variants of clinical significance in molecular oncology laboratories, with reduced time and cost of genetic analysis allowing for strategic patient management.
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Affiliation(s)
- Catherine E Cottrell
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Hussam Al-Kateb
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri.
| | - Andrew J Bredemeyer
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Eric J Duncavage
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - David H Spencer
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Haley J Abel
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Christina M Lockwood
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Ian S Hagemann
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Stephanie M O'Guin
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Lauren C Burcea
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Christopher S Sawyer
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Dayna M Oschwald
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Jennifer L Stratman
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Dorie A Sher
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Mark R Johnson
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Justin T Brown
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Paul F Cliften
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Bijoy George
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Leslie D McIntosh
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Savita Shrivastava
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Tudung T Nguyen
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Jacqueline E Payton
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Mark A Watson
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Seth D Crosby
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Richard D Head
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Robi D Mitra
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Rakesh Nagarajan
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Shashikant Kulkarni
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri; Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Karen Seibert
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Herbert W Virgin
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - Jeffrey Milbrandt
- Department of Genetics, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
| | - John D Pfeifer
- Department of Pathology and Immunology, Genomics and Pathology Services, Washington University School of Medicine, St. Louis, Missouri
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16
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Forsyth LH, Witton J, Brown JT, Randall AD, Jones MW. In Vitro and In Vivo Recording of Local Field Potential Oscillations in Mouse Hippocampus. ACTA ACUST UNITED AC 2012; 2:273-94. [PMID: 26069015 DOI: 10.1002/9780470942390.mo120089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oscillations in hippocampal local field potentials (LFP) reflect the coordinated, rhythmic activity of constituent interneuronal and principal cell populations. Quantifying changes in oscillatory patterns and power therefore provides a powerful metric through which to infer mechanisms and functions of hippocampal network activity at the mesoscopic level, bridging single-neuron studies to behavioral assays of hippocampal function. Here, complementary protocols that enable mechanistic analyses of oscillation generation in vitro (in slices and a whole hippocampal preparation) and functional analyses of hippocampal circuits in behaving mice are described. Used together, these protocols provide a comprehensive view of hippocampal phenotypes in mouse models, highlighting oscillatory biomarkers of hippocampal function and dysfunction. Curr. Protoc. Mouse Biol. 2:273-294 © 2012 by John Wiley & Sons, Inc.
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Affiliation(s)
- L H Forsyth
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - J Witton
- Pfizer Applied Neurophysiology Group, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - J T Brown
- Pfizer Applied Neurophysiology Group, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - A D Randall
- Pfizer Applied Neurophysiology Group, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - M W Jones
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
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17
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Brown JT, Laosinchai-Wolf W, Hedges JB, Watt CD, Van Deerlin VM, Fletcher L, Branford S, Labourier E. Establishment of a standardized multiplex assay with the analytical performance required for quantitative measurement of BCR-ABL1 on the international reporting scale. Blood Cancer J 2011; 1:e13. [PMID: 22829126 PMCID: PMC3255280 DOI: 10.1038/bcj.2011.10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 02/15/2011] [Indexed: 11/26/2022] Open
Abstract
Accurate and standardized methods for the quantitative measurement of BCR–ABL1 are a prerequisite for monitoring of treatment response in t(9;22)-positive leukemia. Here, we describe a novel multiplex assay system based on the proven TaqMan and Armored RNA technologies and optimized for sensitive detection of three BCR–ABL1 fusion transcripts and ABL1 in a single reaction. Analytical experiments confirmed the absence of significant competition between the simultaneous amplification reactions and established the sensitivity, linearity and precision of the assay. Comparative studies with 115 clinical specimens resulted in high qualitative and quantitative agreement with independent singleplex laboratory-developed tests routinely used in clinical testing. Direct comparison with a reference laboratory calibrated to the international scale (IS) demonstrated minimal analytical bias between methods and an overall accuracy and precision within the performance range required for quantitative measurement of BCR–ABL1 on the IS. We conclude that detection of e1a2, b2a2, b3a2 and ABL1 can be achieved in a multiplex assay format compatible with IS reporting. Further clinical validation of the assay could improve the operational efficiency of clinical laboratories, increase their adherence to current recommendations for b2a2/b3a2 reporting on the IS and provide for the first time an opportunity to standardize e1a2-monitoring results.
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18
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Chater TE, Henley JM, Brown JT, Randall AD. Voltage- and temperature-dependent gating of heterologously expressed channelrhodopsin-2. J Neurosci Methods 2010; 193:7-13. [PMID: 20691205 DOI: 10.1016/j.jneumeth.2010.07.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 07/27/2010] [Accepted: 07/27/2010] [Indexed: 10/19/2022]
Abstract
Channelrhodopsins are light-activated channels originally isolated from algae that are being used increasingly as tools to non-invasively stimulate neurones. Despite their widespread use some aspects of their biophysical properties have not been fully characterised. Here we report detailed investigation of the gating kinetics and voltage-dependence of ChR2 transiently expressed in HEK-293 cells. Currents were elicited using light pulses of defined duration and intensity generated by a blue LED. Datasets were gathered both at room temperature (RT, ∼22°C) and 37°C. Current responses to light rose rapidly to a peak and then desensitized to a steady state plateau. When illumination was terminated currents rapidly deactivated. Recovery from desensitization at -85 mV was slow with half-times of 1.4 and 3.1s at 37°C and ∼22°C, respectively. At both temperatures, the reversal potential of ChR2 responses was a few mV positive to 0 mV. Both the peak and plateau phases of ChR2 responses exhibited strong inward rectification with only small outward currents at positive membrane potentials. The rates of ChR2 activation, deactivation and desensitization were ∼2 times faster at 37°C than at ∼22°C. Both the activation and deactivation kinetics of ChR2 were significantly slowed by depolarization at both temperatures. Additionally, the degree of steady state desensitization was greater at more depolarized potentials. The macroscopic desensitization kinetics were not voltage-dependent, but recovery from desensitization was slowed by depolarization. These gating behaviour data provide an important basis for more detailed analysis of the properties and limitations of ChR2 use in more complex systems.
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Affiliation(s)
- T E Chater
- MRC Centre for Synaptic Plasticity, University of Bristol, University Walk, Bristol, UK
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19
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Abstract
Seeds in a conifer cone from the Lower Permian of west Texas contain embryo tissue. These are the oldest plant embryos on record. Their development prior to seed dispersal shows that the sequence of embryo growth typical of most modern seed plants had evolved before the end of the Paleozoic Era.
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20
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Randall AD, Witton J, Booth C, Hynes-Allen A, Brown JT. The functional neurophysiology of the amyloid precursor protein (APP) processing pathway. Neuropharmacology 2010; 59:243-67. [PMID: 20167227 DOI: 10.1016/j.neuropharm.2010.02.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 01/12/2023]
Abstract
Amyloid beta (Abeta) peptides derived from proteolytic cleavage of amyloid precursor protein (APP) are thought to be a pivotal toxic species in the pathogenesis of Alzheimer's disease (AD). Furthermore, evidence has been accumulating that components of APP processing pathway are involved in non-pathological normal function of the CNS. In this review we aim to cover the extensive body of research aimed at understanding how components of this pathway contribute to neurophysiological function of the CNS in health and disease. We briefly outline changes to clinical neurophysiology seen in AD patients before discussing functional changes in mouse models of AD which range from changes to basal synaptic transmission and synaptic plasticity through to abnormal synchronous network activity. We then describe the various neurophysiological actions that are produced by application of exogenous Abeta in various forms, and finally discuss a number or other neurophysiological aspects of the APP pathway, including functional activities of components of secretase complexes other than Abeta production.
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Affiliation(s)
- A D Randall
- MRC Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol School of Medical Sciences, Bristol, UK.
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21
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Brown JT, Kant A, Mailman RB. Rapid, semi-automated, and inexpensive radioimmunoassay of cAMP: application in GPCR-mediated adenylate cyclase assays. J Neurosci Methods 2008; 177:261-6. [PMID: 19007813 DOI: 10.1016/j.jneumeth.2008.10.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 10/08/2008] [Accepted: 10/09/2008] [Indexed: 10/21/2022]
Abstract
Cyclic AMP (cAMP) is an important signal transduction second messenger that is commonly used as a functional mirror on the actions of G protein-coupled receptors that can activate or inhibit adenylate cyclases. A radioimmunoassay for cAMP with femtomole sensitivity was first reported by Steiner more than 30 years ago, and there have been several subsequent modifications that have improved this assay in various ways. Here we describe additional improvement to existing methods that markedly improve speed and reduce cost without sacrificing sensitivity, and is also adaptable to analysis of cGMP. The primary antibody is coupled directly to magnetic beads that are then separated from unbound marker using filtration on microplates. This eliminates the need for a secondary antibody, and markedly increases throughput. In addition, we report a simple, reproducible, and inexpensive method to make the radiomarker used for this assay. Although still requiring the use of radioactivity, the resulting method retains a high degree of accuracy and precision, and is suitable for low-cost high throughput screening. Use of aspects of this method can also improve throughput in other radioimmunoassays.
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Affiliation(s)
- Justin T Brown
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, United States
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22
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Langmead CJ, Austin NE, Branch CL, Brown JT, Buchanan KA, Davies CH, Forbes IT, Fry VAH, Hagan JJ, Herdon HJ, Jones GA, Jeggo R, Kew JNC, Mazzali A, Melarange R, Patel N, Pardoe J, Randall AD, Roberts C, Roopun A, Starr KR, Teriakidis A, Wood MD, Whittington M, Wu Z, Watson J. Characterization of a CNS penetrant, selective M1 muscarinic receptor agonist, 77-LH-28-1. Br J Pharmacol 2008; 154:1104-15. [PMID: 18454168 DOI: 10.1038/bjp.2008.152] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE M1 muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and schizophrenia. However, the discovery of subtype-selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh-binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC-42 (4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine), which bind to an allosteric site and selectively activate the M(1) mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs. EXPERIMENTAL APPROACH In this study, we have compared the pharmacological profile of AC-42 and a close structural analogue, 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and both in vitro and in vivo electrophysiology. KEY RESULTS Calcium mobilization and inositol phosphate accumulation assays revealed that both AC-42 and 77-LH-28-1 display high selectivity to activate the M1 mAChR over other mAChR subtypes. Furthermore, 77-LH-28-1, but not AC-42, acted as an agonist at rat hippocampal M1 receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77-LH-28-1 stimulated cell firing in the rat hippocampus in vivo following subcutaneous administration. CONCLUSIONS AND IMPLICATIONS These data suggest that 77-LH-28-1 is a potent, selective, bioavailable and brain-penetrant agonist at the M1 mAChR and therefore that it represents a better tool than AC-42, with which to study the pharmacology of the M1 mAChR.
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Affiliation(s)
- C J Langmead
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, Essex, UK.
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Ryman-Rasmussen JP, Griffith A, Oloff S, Vaidehi N, Brown JT, Goddard WA, Mailman RB. Functional selectivity of dopamine D1 receptor agonists in regulating the fate of internalized receptors. Neuropharmacology 2006; 52:562-75. [PMID: 17067639 PMCID: PMC1855220 DOI: 10.1016/j.neuropharm.2006.08.028] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 08/29/2006] [Accepted: 08/30/2006] [Indexed: 11/15/2022]
Abstract
Recently, we demonstrated that D(1) agonists can cause functionally selective effects when the endpoints of receptor internalization and adenylate cyclase activation are compared. The present study was designed to probe the phenomenon of functional selectivity at the D(1) receptor further by testing the hypothesis that structurally dissimilar agonists with efficacies at these endpoints that equal or exceed those of dopamine would differ in ability to influence receptor fate after internalization, a functional endpoint largely unexplored for the D(1) receptor. We selected two novel agonists of therapeutic interest that meet these criteria (the isochroman A-77636, and the isoquinoline dinapsoline), and compared the fates of the D(1) receptor after internalization in response to these two compounds with that of dopamine. We found that dopamine caused the receptor to be rapidly recycled to the cell surface within 1h of removal. Conversely, A-77636 caused the receptor to be retained intracellularly up to 48 h after agonist removal. Most surprisingly, the D(1) receptor recovered to the cell surface 48 h after removal of dinapsoline. Taken together, these data indicate that these agonists target the D(1) receptor to different intracellular trafficking pathways, demonstrating that the phenomenon of functional selectivity at the D(1) receptor is operative for cellular events that are temporally downstream of immediate receptor activation. We hypothesize that these differential effects result from interactions of the synthetic ligands with aspects of the D(1) receptor that are distal from the ligand binding domain.
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Affiliation(s)
- Jessica P. Ryman-Rasmussen
- University of North Carolina at Chapel Hill, Curriculum in Toxicology (JPR-R), Departments of Pharmacology (SO, JB, RBM) and Psychiatry, Neurology and Medicinal Chemistry (RBM), Chapel Hill, NC 27599
| | - Adam Griffith
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125
| | - Scott Oloff
- University of North Carolina at Chapel Hill, Curriculum in Toxicology (JPR-R), Departments of Pharmacology (SO, JB, RBM) and Psychiatry, Neurology and Medicinal Chemistry (RBM), Chapel Hill, NC 27599
| | - Nagarajan Vaidehi
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125
| | - Justin T. Brown
- University of North Carolina at Chapel Hill, Curriculum in Toxicology (JPR-R), Departments of Pharmacology (SO, JB, RBM) and Psychiatry, Neurology and Medicinal Chemistry (RBM), Chapel Hill, NC 27599
| | - William A. Goddard
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125
| | - Richard B. Mailman
- University of North Carolina at Chapel Hill, Curriculum in Toxicology (JPR-R), Departments of Pharmacology (SO, JB, RBM) and Psychiatry, Neurology and Medicinal Chemistry (RBM), Chapel Hill, NC 27599
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Brown JT, Lahey C, Laosinchai-Wolf W, Hadd AG. Polymorphisms in the glucocerebrosidase gene and pseudogene urge caution in clinical analysis of Gaucher disease allele c.1448T>C (L444P). BMC Med Genet 2006; 7:69. [PMID: 16887033 PMCID: PMC1559599 DOI: 10.1186/1471-2350-7-69] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 08/03/2006] [Indexed: 11/24/2022]
Abstract
Background Gaucher disease is a potentially severe lysosomal storage disorder caused by mutations in the human glucocerebrosidase gene (GBA). We have developed a multiplexed genetic assay for eight diseases prevalent in the Ashkenazi population: Tay-Sachs, Gaucher type I, Niemann-Pick types A and B, mucolipidosis type IV, familial dysautonomia, Canavan, Bloom syndrome, and Fanconi anemia type C. This assay includes an allelic determination for GBA allele c.1448T>C (L444P). The goal of this study was to clinically evaluate this assay. Methods Biotinylated, multiplex PCR products were directly hybridized to capture probes immobilized on fluorescently addressed microspheres. After incubation with streptavidin-conjugated fluorophore, the reactions were analyzed by Luminex IS100. Clinical evaluations were conducted using de-identified patient DNA samples. Results We evaluated a multiplexed suspension array assay that includes wild-type and mutant genetic determinations for Gaucher disease allele c.1448T>C. Two percent of samples reported to be wild-type by conventional methods were observed to be c.1448T>C heterozygous using our assay. Sequence analysis suggested that this phenomenon was due to co-amplification of the functional gene and a paralogous pseudogene (ΨGBA) due to a polymorphism in the primer-binding site of the latter. Primers for the amplification of this allele were then repositioned to span an upstream deletion in the pseudogene, yielding a much longer amplicon. Although it is widely reported that long amplicons negatively impact amplification or detection efficiency in recently adopted multiplex techniques, this assay design functioned properly and resolved the occurrence of false heterozygosity. Conclusion Although previously available sequence information suggested GBA gene/pseudogene discrimination capabilities with a short amplified product, we identified common single-nucleotide polymorphisms in the pseudogene that required amplification of a larger region for effective discrimination.
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Brown JT, Nichols DE, Mailman RB. THE ROLE OF THREONINE3.37 [T3.37] IN D1‐LIKE DOPAMINE RECEPTOR ACTIVATION. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a246-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - David E Nichols
- Medicinal Chemistry & Molecular PharmacologyPurdue UniversityHeine Pharmacy BldgW. LatayetteIN47907
| | - Richard B Mailman
- Pharamcology & PsychiatryUniversity of North CarolinaUNC Neuroscience HospitalChapel HillNC27599
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Piccinin S, Randall AD, Brown JT. KCNQ/Kv7 channel regulation of hippocampal gamma-frequency firing in the absence of synaptic transmission. J Neurophysiol 2006; 95:3105-12. [PMID: 16467425 DOI: 10.1152/jn.01083.2005] [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] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Synchronous neuronal firing can be induced in hippocampal slices in the absence of synaptic transmission by lowering extracellular Ca2+ and raising extracellular K+. However, the ionic mechanisms underlying this nonsynaptic synchronous firing are not well understood. In this study we have investigated the role of KCNQ/Kv7 channels in regulating this form of nonsynaptic bursting activity. Incubation of rat hippocampal slices in reduced (<0.2 mM) [Ca2+]o and increased (6.3 mM) [K+]o, blocked synaptic transmission, increased neuronal firing, and led to the development of spontaneous periodic nonsynaptic epileptiform activity. This activity was recorded extracellularly as large (4.7 +/- 1.9 mV) depolarizing envelopes with superimposed high-frequency synchronous population spikes. These intraburst population spikes initially occurred at a high frequency (about 120 Hz), which decayed throughout the burst stabilizing in the gamma-frequency band (30-80 Hz). Further increasing [K+]o resulted in an increase in the interburst frequency without altering the intraburst population spike frequency. Application of retigabine (10 microM), a Kv7 channel modulator, completely abolished the bursts, in an XE-991-sensitive manner. Furthermore, application of the Kv7 channel blockers, linopirdine (10 microM) or XE-991 (10 microM) alone, abolished the gamma frequency, but not the higher-frequency population spike firing observed during low Ca2+/high K+ bursts. These data suggest that Kv7 channels are likely to play a role in the regulation of synchronous population firing activity.
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Affiliation(s)
- S Piccinin
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol School of Medical Sciences, Bristol, UK
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Abstract
This study investigated ethnic and gender differences in reported resource losses and gains for recovering substance abusers living in Oxford Houses (OH). Participants (n = 829) completed a version of Hobfoll's (1998) Conservation of Resources (COR) Evaluation. Results indicated significant individual differences in resources, based on gender, ethnicity, and the length of OH residential stay. Men reported fewer resource gains and losses than women. With respect to ethnicity, African-Americans reported greater gains and losses in resources than European-Americans. Individuals with less time in an OH also reported having experienced more losses in the past 3 months.
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Nanín JE, Parsons JT, Bimbi DS, Grov C, Brown JT. Community reactions to campaigns addressing crystal methamphetamine use among gay and bisexual men in New York City. J Drug Educ 2006; 36:297-315. [PMID: 17533803 PMCID: PMC1885400 DOI: 10.2190/9818-1w43-1876-2062] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Crystal methamphetamine (aka "crystal meth") use with high-risk sex has become an emerging health problem for gay and bisexual men in New York City since the late 1990s. Public health campaigns were eventually developed to encourage gay and bisexual men to avoid or reconsider using crystal meth. Reactions to three campaigns were measured with a cross-sectional survey administered in 2004. Among an ethnically-diverse sample of 971 gay and bisexual men, 61.8% reported seeing the campaigns. Those who reported ever using crystal meth, recent use, and recent use with sex were significantly more likely to have seen the campaigns. In general, white men, HIV-negative men, and men not currently using crystal meth responded more positively to the campaigns than their counterparts; yet, more men of color reported having discussions with partners and friends about their crystal use as a result of these campaigns. Implications for researchers and practitioners are discussed.
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Affiliation(s)
- José E Nanín
- Kingsborough Community College of the City University of New York and the Center for HIV Educational Studies and Training, USA
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Brown JT, Teriakidis A, Randall AD. A pharmacological investigation of the role of GLUK5-containing receptors in kainate-driven hippocampal gamma band oscillations. Neuropharmacology 2005; 50:47-56. [PMID: 16153668 DOI: 10.1016/j.neuropharm.2005.07.017] [Citation(s) in RCA: 16] [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] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 07/22/2005] [Accepted: 07/22/2005] [Indexed: 10/25/2022]
Abstract
Low concentrations of kainate can induce gamma frequency (25-80 Hz) oscillations in hippocampal slices as well as other brain structures in vitro. Little is known, however, about the kainate receptor (KAR) subtypes that underlie this type of rhythmic neuronal network activity. In this study, the role of GLU(K5) subunit-containing KARs in kainate-induced hippocampal gamma frequency oscillations was assessed using GLU(K5)-selective pharmacological ligands. Activation of GLU(K5)-containing subunits using the selective agonists (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid (ATPA; 0.1-1 microM) or iodowillardiine (0.1-1 microM) failed to induce gamma frequency oscillations in area CA3 of the rat hippocampal slice. Likewise, preincubation with a selective GLU(K5) antagonist, (RS)-3-(2-carboxybenzyl)willardiine (UBP296), did not prevent the appearance of gamma oscillations induced by 150 nM kainate. However, addition of UBP296 (10 microM) to hippocampal slices in which kainate-driven gamma oscillations were pre-established resulted in an approximately 50% reduction in gamma frequency power. These effects occurred in the absence of any effect on AMPA receptor-mediated synaptic transmission. Furthermore, carbachol-induced gamma oscillations were also unaffected by application of UBP296. These results suggest that GLU(K5)-containing KARs are not alone sufficient to generate gamma frequency oscillations, but are involved in maintaining neuronal network activity induced by the actions of kainate at other KARs such as GLU(K6).
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Affiliation(s)
- J T Brown
- Neurology and GI Centre of Excellence for Drug Discovery, GlaxoSmithKline Research and Development Limited, New Frontiers Science Park (North), Harlow, Essex, UK.
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Spencer JP, Brown JT, Richardson JC, Medhurst AD, Sehmi SS, Calver AR, Randall AD. Modulation of hippocampal excitability by 5-HT4 receptor agonists persists in a transgenic model of Alzheimer's disease. Neuroscience 2005; 129:49-54. [PMID: 15489027 DOI: 10.1016/j.neuroscience.2004.06.070] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2004] [Indexed: 10/26/2022]
Abstract
5-HT(4) receptors are widely distributed in both peripheral and central nervous systems where they couple, via a G-protein, to the activation of adenylate cyclase. In the brain, the highest 5-HT(4) receptor densities are found in the limbic system, including the hippocampus and frontal cortex. It has been suggested that activation of these receptors may be of therapeutic benefit in diseases that produce cognitive deficits such as Alzheimer's disease (AD). Previous electrophysiological studies have shown that the 5-HT(4) agonist, Zacopride, can increase population spike amplitude recorded in region CA1 of rat hippocampal slices in a cyclic AMP (cAMP)/cAMP-dependent protein kinase A-dependent manner. We report here that the 5-HT(4) agonist, Prucalopride, and the 5-HT(4) partial agonist, SL65.0155, produce a similar effect in rat hippocampal slices and that the specific 5-HT(4) antagonist, GR113808, blocks these effects. To investigate the potential use of 5-HT(4) agonists in the treatment of AD, Prucalopride was applied to hippocampal slices from a transgenic mouse line that overexpresses the Abeta peptide. Despite the deficit in synaptic transmission present in these mice, the percentage increase of the CA1 population spike induced by Prucalopride was the same as that observed in wild-type mice. These data support 5-HT(4) receptors as a target for cognitive enhancement and suggest that a partial agonist would be sufficient to produce benefits, while reducing potential peripheral side effects. In addition, we show that 5-HT(4) receptors remain functional in the presence of excess Abeta peptide and may therefore be a useful target in AD.
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Affiliation(s)
- J P Spencer
- Neurology and GI CEDD, GlaxoSmithKline, Harlow, Essex CM19 5AW, UK.
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Harrison SM, Reavill C, Brown G, Brown JT, Cluderay JE, Crook B, Davies CH, Dawson LA, Grau E, Heidbreder C, Hemmati P, Hervieu G, Howarth A, Hughes ZA, Hunter AJ, Latcham J, Pickering S, Pugh P, Rogers DC, Shilliam CS, Maycox PR. LPA1 receptor-deficient mice have phenotypic changes observed in psychiatric disease. Mol Cell Neurosci 2004; 24:1170-9. [PMID: 14697676 DOI: 10.1016/j.mcn.2003.09.001] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [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: 11/26/2022] Open
Abstract
Several psychiatric diseases, including schizophrenia, are thought to have a developmental aetiology, but to date no clear link has been made between psychiatric disease and a specific developmental process. LPA(1) is a G(i)-coupled seven transmembrane receptor with high affinity for lysophosphatidic acid. Although LPA(1) is expressed in several peripheral tissues, in the nervous system it shows relatively restricted temporal expression to neuroepithelia during CNS development and to myelinating glia in the adult. We report the detailed neurological and behavioural analysis of mice homozygous for a targeted deletion at the lpa(1) locus. Our observations reveal a marked deficit in prepulse inhibition, widespread changes in the levels and turnover of the neurotransmitter 5-HT, a brain region-specific alteration in levels of amino acids, and a craniofacial dysmorphism in these mice. We suggest that the loss of LPA(1) receptor generates defects resembling those found in psychiatric disease.
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Affiliation(s)
- S M Harrison
- Comparative Genomics, GlaxoSmithKline, Harlow, Essex, UK
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Abstract
Recent experiments have demonstrated that formation of functional type B gamma-aminobutyric acid (GABA(B)) receptors requires co-expression of two receptor subunits, GABA(B1) and GABA(B2). Despite the identification of these subunits and a number of associated splice variants, there has been little convincing evidence of pharmacological diversity between GABA(B) receptors comprising different subunit combinations. However, Ng et al. [Mol. Pharmacol., 59 (2000) 144] have recently suggested a novel and important pharmacological difference between GABA(B) receptor heterodimers expressing the GABA(B1a) and GABA(B1b) receptor subunits. This study suggested that the antiepileptic GABA analogue gabapentin (Neurontin) is an agonist at GABA(B) receptors expressing the GABA(B1a) but not the GABA(B1b) receptor subunit. The importance of this finding with respect to identifying novel GABA(B) receptor subunit specific agonists prompted us to repeat these experiments in our own [35S]-GTPgammaS binding and second messenger assay systems. Here we report that gabapentin was completely inactive at recombinant GABA(B) heterodimers expressing either GABA(B1a) or GABA(B1b) receptor subunits in combination with GABA(B2) receptor subunits. In addition, in both CA1 and CA3 pyramidal neurones from rodent hippocampal slices we were unable to demonstrate any agonist-like effects of gabapentin at either pre- or post-synaptic GABA(B) receptors. In contrast, gabapentin activated a GABA(A) receptor mediated chloride conductance. Our data suggest that gabapentin is not a GABA(B)-receptor agonist let alone a GABA(B) receptor subunit selective agonist.
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Affiliation(s)
- C Lanneau
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park North, Third Avenue, Essex, CM19 5AW, Harlow, UK
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Brown JT, Johnson AW. A cis-acting element known to block 3' mRNA degradation enhances expression of polyA-minus mRNA in wild-type yeast cells and phenocopies a ski mutant. RNA 2001; 7:1566-1577. [PMID: 11720286 PMCID: PMC1370199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
mRNA lacking a 3' polyA tail is not translated efficiently in wild-type eukaryotic cells, but is translated efficiently in yeast ski mutants. This enhanced expression could be due to altered translational specificity. However, as the SKI genes are required for 3' mRNA degradation, it could be a consequence of inhibition of 3' mRNA decay. Therefore, we asked if inhibition of 3' decay of a polyA-minus mRNA in cis would allow its efficient expression in wild-type cells. Capped in vitro reporter transcripts were prepared with or without a 3' cis-acting element known to inhibit 3' degradation (oligoG) and electroporated into yeast cells. The addition of oligoG to a polyA-minus mRNA enhanced expression 30-fold in wild-type cells. This level of expression was the same as that for an oligoG-minus, polyA-minus transcript in a ski mutant. The addition of oligoG did not significantly enhance the expression of polyA-minus mRNA in a ski mutant. The oligoG-dependent increase in expression was due to an increase in initial rate of translation and an increase in the functional half-life of the mRNA, similar to the effects observed in a ski mutant. The enhanced expression of the oligoG-containing RNA did not require Pab1p. We conclude that the enhanced translation of polyA-minus RNA in a ski mutant is due to inhibition of 3' mRNA degradation. Furthermore, a polyA-minus mRNA is expressed in wild-type cells when terminated in an element known to inhibit 3' decay in cis.
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Affiliation(s)
- J T Brown
- Department of Molecular Genetics and Microbiology and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, 78712-1095, USA
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Brown JT, Yang X, Johnson AW. Inhibition of mRNA turnover in yeast by an xrn1 mutation enhances the requirement for eIF4E binding to eIF4G and for proper capping of transcripts by Ceg1p. Genetics 2000; 155:31-42. [PMID: 10790382 PMCID: PMC1461062 DOI: 10.1093/genetics/155.1.31] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Null mutants of XRN1, encoding the major cytoplasmic exoribonuclease in yeast, are viable but accumulate decapped, deadenylated transcripts. A screen for mutations synthetic lethal with xrn1Delta identified a mutation in CDC33, encoding eIF4E. This mutation (glutamate to glycine at position 72) affected a highly conserved residue involved in interaction with eIF4G. Synthetic lethality between xrn1 and cdc33 was not relieved by high-copy expression of eIF4G or by disruption of the yeast eIF4E binding protein Caf20p. High-copy expression of a mutant eIF4G defective for eIF4E binding resulted in a dominant negative phenotype in an xrn1 mutant, indicating the importance of this interaction in an xrn1 mutant. Another allele of CDC33, cdc33-1, along with mutations in CEG1, encoding the nuclear guanylyltransferase, were also synthetic lethal with xrn1Delta, whereas mutations in PRT1, encoding a subunit of eIF3, were not. Mutations in CDC33, CEG1, PRT1, PAB1, and TIF4631, encoding eIF4G1, have been shown to lead to destabilization of mRNAs. Although such destabilization in cdc33, ceg1, and pab1 mutants can be partially suppressed by an xrn1 mutation, we observed synthetic lethality between xrn1 and either cdc33 or ceg1 and no suppression of the inviability of a pab1 null mutation by xrn1Delta. Thus, the inhibition of mRNA turnover by blocking Xrn1p function does not suppress the lethality of defects upstream in the turnover pathway but it does enhance the requirement for (7)mG caps and for proper formation of the eIF4E/eIF4G cap recognition complex.
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Affiliation(s)
- J T Brown
- Section of Molecular Genetics and Microbiology and the Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-1095, USA
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Abstract
The yeast superkiller (SKI) genes were originally identified from mutations allowing increased production of killer toxin encoded by M "killer" virus, a satellite of the dsRNA virus L-A. XRN1 (SKI1) encodes a cytoplasmic 5'-exoribonuclease responsible for the majority of cytoplasmic RNA turnover, whereas SKI2, SKI3, and SKI8 are required for normal 3'-degradation of mRNA and for repression of translation of poly(A) minus RNA. Ski2p is a putative RNA helicase, Ski3p is a tetratricopeptide repeat (TPR) protein, and Ski8p contains five WD-40 (beta-transducin) repeats. An xrn1 mutation in combination with a ski2, ski3, or ski8 mutation is lethal, suggesting redundancy of function. Using functional epitope-tagged Ski2, Ski3, and Ski8 proteins, we show that Ski2p, Ski3p, and Ski8p can be coimmunoprecipitated as an apparent heterotrimeric complex. With epitope-tagged Ski2p, there was a 1:1:1 stoichiometry of the proteins in the complex. Ski2p did not associate with Ski3p in the absence of Ski8p, nor did Ski2p associate with Ski8p in the absence of Ski3p. However, the Ski3p/Ski8p interaction did not require Ski2p. In addition, ski6-2 or ski4-1 mutations or deletion of SKI7 did not affect complex formation. The identification of a complex composed of Ski2p, Ski3p, and Ski8p explains previous results showing phenotypic similarity between mutations in SKI2, SKI3, and SKI8. Indirect immunofluorescence of Ski3p and subcellular fractionation of Ski2p and Ski3p suggest that Ski2p and Ski3p are cytoplasmic. These data support the idea that Ski2p, Ski3p, and Ski8p function in the cytoplasm in a 3'-mRNA degradation pathway.
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Affiliation(s)
- J T Brown
- Section of Molecular Genetics and Microbiology and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, 78712-1095, USA
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Kurtis KE, Monteiro PJ, Brown JT, Meyer-Ilse W. High resolution transmission soft X-ray microscopy of deterioration products developed in large concrete dams. J Microsc 1999; 196 (Pt 3):288-98. [PMID: 10594769 DOI: 10.1046/j.1365-2818.1999.00587.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In concrete structures, the reaction of certain siliceous aggregates with the highly alkaline concrete pore solution produces an alkali-silicate gel that can absorb water and expand. This reaction can lead to expansion, cracking, increased permeability, and decreased strength of the concrete. Massive concrete structures, such as dams, are particularly susceptible to the damage caused by the alkali-silica reaction because of the availability of water and because massive gravity dams usually do not contain steel reinforcement to restrain the expansion. Both the cement hydration products and alkali-silica reaction products are extremely sensitive to humidity. Consequently, characterization techniques that require high vacuum or drying, as many existing techniques do, are not particularly appropriate for the study of the alkali-silica reaction because artefacts are introduced. Environmental scanning electron micrographs and scanning electron micrographs with energy dispersive X-ray analysis results demonstrate the effect of drying on the morphology and chemical composition of the alkali-silicate reaction gel. Thus, the impetus for this research was the need to observe and characterize the alkali-silica reaction and its gel product on a microscopic level in a wet environment (i.e. without introducing artefacts due to drying). Only soft X-ray transmission microscopy provides the required high spatial resolution needed to observe the reaction process in situ. The alkali-silica reaction can be observed over time, in a wet condition, and at normal pressures, features unavailable with most other high resolution techniques. Soft X-rays also reveal information on the internal structure of the sample. The purpose of this paper is to present research, obtained using transmission soft X-ray microscopy, on the effect of concrete pore solution cations, namely sodium and calcium, on the product formed as a result of alkali attack. Alkali-silicate reaction (ASR) gel was obtained from the FURNAS Dam in Minas Gerais, Brazil. Images of the ASR gel in sodium hydroxide indicated dissolution and repolymerization of the silicate into a less dense form, demonstrating the expansive nature of the gel when exposed to alkalis. In the calcium hydroxide solution, ASR gel, silica fume, and chemical grade silica gel each reacted with the calcium ions in solution to produce a calcium silicate hydrate precursor with a lathlike, branching morphology. The distinctive spherulitic microstructure formed during this reaction was identified as the 'sheaf of wheat' morphology, previously described in the literature. In addition, the development of the sheaf of wheat morphology was documented over time. These results suggest that of the cations studied in this investigation, it is the alkalis in concrete pore solution that produce the expansive ASR gel, while reaction with calcium ions does not result in expansion or damage to the concrete structure. More broadly, these results demonstrate the advantage of transmission soft X-ray microscopy for the study of the alkali-silica reaction, indicating the value of this technique for further studies in concrete technology.
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Affiliation(s)
- KE Kurtis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Abstract
Humic substances (HSs) are the natural organic polyelectrolytes formed from the biochemical weathering of plant and animal remains. Their macromolecular structure and chemistry determine their role in biogeochemical processes. In situ spectromicroscopic evidence showed that the HS macromolecular structures (size and shape) vary as a function of HS origin (soil versus fluvial), solution chemistry, and the associated mineralogy. The HSs do not simply form coils in acidic or strong electrolyte solutions and elongated structures in dilute alkaline solutions. The macromolecular structural changes of HSs are likely to modify contaminant solubility, biotransformation, and the carbon cycle in soils and sediments.
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Affiliation(s)
- SC Myneni
- Earth Sciences Division, Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. Agriculture Experimental Station, University o
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Yeung J, Brown JT, Nair A, Meites E, Coppel RL, Mohandas N, Meyer-Ilse W, Magowan C. X-ray microscopic visualization of specific labeling of adhesive molecule CD36 and cytoadherence by Plasmodium falciparum infected erythrocytes. Res Commun Mol Pathol Pharmacol 1998; 99:245-58. [PMID: 9591321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated the cytoadherence of Plasmodium falciparum infected erythrocytes to target cells that express CD36 by soft x-ray microscopy. Using immunogold beads enhanced with silver, we localized CD36 on the surface of intact melanoma cells and throughout Triton extracted melanoma cells. We examined the orientation of parasites within erythrocytes that bound to target cells, and the interactions between the red cell membrane and the target cell, and we confirmed that fibrillar structures on the surface of melanoma and endothelial cells can be involved in the association between infected erythrocytes and melanoma cells or endothelial cells.
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Affiliation(s)
- J Yeung
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA
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Magowan C, Brown JT, Liang J, Heck J, Coppel RL, Mohandas N, Meyer-Ilse W. Intracellular structures of normal and aberrant Plasmodium falciparum malaria parasites imaged by soft x-ray microscopy. Proc Natl Acad Sci U S A 1997; 94:6222-7. [PMID: 9177198 PMCID: PMC21030 DOI: 10.1073/pnas.94.12.6222] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Soft x-ray microscopy is a novel approach for investigation of intracellular organisms and subcellular structures with high spatial resolution. We used x-ray microscopy to investigate structural development of Plasmodium falciparum malaria parasites in normal and genetically abnormal erythrocytes and in infected erythrocytes treated with cysteine protease inhibitors. Investigations in normal red blood cells enabled us to recognize anomalies in parasite structures resulting from growth under unfavorable conditions. X-ray microscopy facilitated detection of newly elaborated structures in the cytosol of fixed, unstained, intact erythrocytes, redistribution of mass (carbon) in infected erythrocytes, and aberrant parasite morphology. In cysteine protease inhibitor-treated, infected erythrocytes, high concentrations of material were detected in abnormal digestive vacuoles and aggregated at the parasite plasma membrane. We have demonstrated that an abnormal host erythrocyte skeleton affects structural development of parasites and that this aberrant development can be detected in the following generation when parasites from protein 4.1-deficient red blood cells infect normal erythrocytes. This work extends our current understanding of the relationship between the host erythrocyte membrane and the intraerythrocytic malaria parasite by demonstrating for the first time that constituents of the erythrocyte membrane play a role in normal parasite structural development.
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Affiliation(s)
- C Magowan
- Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
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Brown JT, Ellis L, Guerrina ML, Paxton DM, Poleno P. The relationship between the frequency of exercise and the age of onset of sexual intercourse in adolescent females. Nurse Pract 1997; 22:16-8, 171. [PMID: 9055314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Abstract
Tumor cell invasion surrounding intracerebrally implanted tumors in rats was studied by comparing the results of cerebral microangiography, fluorescence imaging of blood-brain barrier (BBB) disruption and histopathology. Each comparison was on subsequent sections taken from an initial 1 mm coronal slice of brain taken through the cell injection site containing tumor using the RT-2 glioma model. Tumor extension was assessed at 3, 5, 7 and 9 days after tumor implantation. Analysis of the brain adjacent to tumor shows that the actual tumor cell invasion area is greater than the area of BBB disruption at later stages of tumor growth and the extent of tumor vascularization lies well within the area defined by the extent of tumor cell invasion. Furthermore, this study found that the size of the area of tumor cell invasion remains relatively stable in proportion to the solid tumor mass at various stages of growth such that the area of tumor invaded brain was approximately 2.5 times greater than the area outlined by solid tumor mass. We conclude that measurement of the solid tumor mass, tumor vascular area and region of blood-brain barrier disruption due to tumor, grossly underestimate the total tumor volume. Therapies aimed at controlling glial tumor growth must, therefore, include normal appearing regions of brain peripheral to the abnormal region defined as tumor and tumor invaded brain as defined by radiographic and imaging studies.
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Affiliation(s)
- Y Ji
- Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, USA
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Brown JT. A piece of my mind. A jack of all trades. JAMA 1996; 276:264. [PMID: 8656522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Brown JT, Miller A. Peroneal tenosynovitis following acute gonococcal infection. Am J Orthop (Belle Mead NJ) 1996; 25:445-7. [PMID: 8798987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A 17-year-old adolescent girl presented with tenosynovitis of the peroneal tendons following diagnosis and treatment of an endocervical gonococcal infection. The need for careful history in any sexually active adolescent is emphasized. Acute peroneal tenosynovitis, although not previously cited in the literature, can occur and should be suspected.
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Affiliation(s)
- J T Brown
- Community General Osteopathic Hospital, Harrisburg, Pennsylvania, USA
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Abstract
The widespread acceptance of photodynamic therapy (PDT), a potential adjuvant brain tumor therapy under clinical evaluation since 1980, has been partially restrained by its potential toxicity toward normal brain tissue. This study examined PDT-produced injury of normal rat brain as a function of photosensitizer dose. Brain injury was characterized by correlating measurements of the area of cerebral edema using T2-weighted magnetic resonance images, measurement of brain water content at the lesion site, microscopic examination of histological sections through the PDT lesion, and by evaluation of the area of blood brain barrier (BBB) disruption using computerized morphometric analysis of the region of Evans blue (EB) dye-labelled albumin extravasation. Monochromatic red light (630 nm) was delivered intracerebrally using a 5-mm-long cylindrical, diffusion-tip optical fiber at a constant energy dose of 15 joules. A Photofrin dose of 2 mg/kg of body weight produced a transient breakdown in the blood brain barrier around the site of the implanted optical fiber demonstrated by magnetic resonance imaging (MRI), extravasation of EB dye and pallor on hematoxylin and eosin-stained microscopic tissue sections. A much larger area of BBB disruption was seen at a dose of 4 mg/kg of Photofrin, and this drug dose resulted in significant permanent brain injury. In this model, a Photofrin dose of 4 mg/kg body weight is not tolerated by the normal brain.
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Affiliation(s)
- Y Ji
- Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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Weinberger M, Saunders AF, Bearon LB, Gold DT, Brown JT, Samsa GP, Loehrer PJ. Physician-related barriers to breast cancer screening in older women. J Gerontol 1992; 47 Spec No:111-7. [PMID: 1430872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Despite evidence that annual mammographic screening in women 50 years and older reduces mortality, surveys of physicians and patients have repeatedly demonstrated that annual screening mammography is not performed. The fundamental question addressed in this chapter is: If the assumption is made that the scientific evidence supports the use of mammography, what, then, are physician-related barriers to mammographic screening of elderly women? Using a model that classifies barriers to implementing prevention protocols into three categories (predisposing, enabling, and reinforcing factors), literature is reviewed to help identify reasons for low mammographic screening rates, especially in elderly women. This article concludes with a discussion of strategies that may help overcome barriers to mammographic screening in elderly women.
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Abstract
OBJECTIVE To estimate the frequency with which patients are incorrectly used as the unit of analysis among statistical calculations in published studies of physicians' patient care behavior. DESIGN Retrospective review of studies published during 1980-1990. ARTICLES: 54 articles retrieved by a computerized search using medical subject headings for physicians and study characteristics. Article selection criteria included the requirement that the physician should have been the correct unit of analysis. INTERVENTION Presence of the error was determined by consensus using published criteria. MAIN RESULTS The error was present in 38 articles (70%). The number of study physicians was reported in 35 articles (65%). The error was found in 57% of articles that reported the number of study physicians and in 95% of those that did not. The error rate was not lower among articles published more recently nor among those published in journals with higher rates of article citations in the medical literature. CONCLUSION The unit of analysis error occurs frequently and can generate artificially low p values. Failure to report the number of study physicians can be a clue that this type of error has been made.
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Affiliation(s)
- G W Divine
- Department of Community and Family Medicine, Duke University, Durham, NC
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Abstract
The effectiveness of intratumoral photoradiation in photodynamic therapy (PDT) using a polyporphyrin photosensitizer was studied in the RT-2 rat glioma model. One week after intracerebral implantation of RT-2 cells, experimental rats received a single i.p. injection of 2 mg/kg of Photofrin. After administration of the photosensitizer (48 h), the tumors were partially resected and the exposed cavity was irradiated with 15 J of laser light at a wavelength of 630 nm. Further treatment with a large craniectomy significantly enhanced rat survival. Control rats which received no photosensitizer but were treated with surgery, alone or in combination with laser irradiation, succumbed from early tumor recurrence. Photodynamic therapy without decompressive surgery resulted in hemorrhagic infarction of residual tumor and adjacent brain with focal cerebral edema which resulted in cerebral herniation and early death. Our results indicate that photodynamic therapy is effective in treating residual brain tumor but at the expense of brain tissue surrounding the tumor. Unless relieved, intracranial pressure from photodynamic therapy-associated cerebral edema in this animal model resulted in shortened survival.
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Affiliation(s)
- Y Ji
- Division of Neurosurgery, University of North Carolina, Chapel Hill 27599-7060
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48
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Abstract
Photofrin (a polyporphyrin mixture) distribution in a rat glioma model was studied in relation to changes in the blood brain barrier (BBB). At selected intervals after intraperitoneal injection of Photofrin, the concentration of polyporphyrins (PP) and Evans Blue Dye, an indicator of BBB permeability, were determined for tumor, brain adjacent to tumor (BAT), and normal brain tissue. Contrary to earlier reports of maximal accumulation at 4-24 hours, tumor levels of PP increased throughout the 96 hour measurement period. During the early stages of tumor development, PP uptake by tumor appeared to be less correlated to BBB disruption. We conclude that passive diffusion through an incompetent BBB does not completely explain PP accumulation in tumor tissue.
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Affiliation(s)
- Y Ji
- Division of Neurological Surgery, University of North Carolina, Chapel Hill 27599-7060
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Abstract
A case of traumatic spondylolisthesis of C6 and C7 is presented. The mechanism of injury and the therapeutic implications are discussed.
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Affiliation(s)
- R A Rovin
- Division of Neurological Surgery, Northwestern University Medical School, Chicago, Illinois
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50
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Abstract
The effect on normal brain of continuous interstitial laser irradiation at 630 nm through an implanted cylindrical-shape, diffusion-tipped optical fiber was studied in the rat. Brain water content in the laser irradiation area (LIA) and Evans blue (EB) dye content in selected areas of the brain were measured for different laser power outputs from 0 to 250 mW after 5 minutes of photoradiation. The degree and nature of tissue damage was examined histologically and correlated with the laser power level. There is significant brain damage, blood brain barrier (BBB) disruption, and brain edema in LIA for laser power outputs in excess of 100 mW from the diffusion tip (p less than 0.001). Brain edema in the LIA is strongly correlated with BBB disruption indicated by the presence of EB. Histologically, the cortical surface was more susceptible than deeper white matter regions to interstitial laser irradiation. Possible indirect mechanisms of brain injury from interstitial laser irradiation are discussed.
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Affiliation(s)
- Y Ji
- Division of Neurological Surgery, University of North Carolina, Chapel Hill 27599-7060
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