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Susey K, Hanin M, Wortner A, Mandich M, Scott K, Stephenson K, Shepherd E, Mehling M. Validity and reliability of the behavioral signs of respiratory instability (BSRI) © scale during activity for infants with bronchopulmonary dysplasia. J Perinatol 2023; 43:1015-1019. [PMID: 37185368 PMCID: PMC10129300 DOI: 10.1038/s41372-023-01682-9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/17/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023]
Abstract
OBJECTIVE There is no reliable evidence on how best to evaluate the overall status of infants with severe forms of bronchopulmonary dysplasia (BPD). The Behavioral Signs of Respiratory Instability (BSRI) scale was developed as an objective measure of developmental capacity during occupational and physical therapy sessions. The purpose of this study was to determine the psychometric properties of the BSRI Scale. STUDY DESIGN The BSRI and Respiratory Severity Score (RSS) were compared for 25 infants with BPD and 15 infants without BPD. A cross-sectional design was used to test inter-rater reliability among 10 NICU occupational and physical therapists. A prospective cohort design was used to evaluate validity. RESULTS The BSRI demonstrated good to excellent inter-rater reliability (ρ = 0.47-0.91) and was strongly correlated with RSS (ρ = -0.77, p < 0.001; concurrent validity). CONCLUSION The BSRI Scale has preliminary psychometric support. Standardized measures like the BSRI may provide accurate, objective data that can improve care planning within interdisciplinary teams that supports brain growth and potentially improves neurodevelopment.
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Affiliation(s)
- K Susey
- Neonatal Therapy Department, Nationwide Children's Hospital, Columbus, OH, USA.
| | - M Hanin
- Neonatal Therapy Department, Nationwide Children's Hospital, Columbus, OH, USA
| | - A Wortner
- Neonatal Therapy Department, Nationwide Children's Hospital, Columbus, OH, USA
| | - M Mandich
- Division of Physical Therapy, West Virginia University, Morgantown, WV, USA
| | - K Scott
- School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - K Stephenson
- Department of Psychology, Nationwide Children's Hospital, Columbus, OH, USA
| | - E Shepherd
- Comprehensive Center for Bronchopulmonary Dysplasia, Nationwide Children's Hospital, Columbus, OH, USA
| | - M Mehling
- Department of Psychology, Nationwide Children's Hospital, Columbus, OH, USA
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James G, Stephenson K, Callaghan-Gillespie M, Kamara MT, Park HG, Brenna JT, Manary MJ. Docosahexaenoic Acid Stability in Ready-to-Use Therapeutic Food. Foods 2023; 12:foods12020308. [PMID: 36673399 PMCID: PMC9858440 DOI: 10.3390/foods12020308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 01/11/2023] Open
Abstract
Ready-to-use therapeutic food (RUTF) is used to treat young children diagnosed with severe acute malnutrition. RUTF with low and balanced linoleic and alpha-linolenic acid, plus omega-3 docosahexaenoic acid (DHA), supports long-term cognitive recovery. DHA is prone to degradation due to peroxidation, possibly exacerbated by the iron inherently in RUTF. Our goals were to prepare benchtop and manufacturing scale of RUTF formulations that include DHA and measure its retention. Twenty-seven RUTF formulas with base ingredients, including oats, high oleic or commodity peanuts, and encapsulated or oil-based DHA at various levels were prepared at benchtop scale, followed by seven months of climate-controlled storage. These pilot samples had similar relative DHA retention. At the manufacturing scale, DHA was added at one of two stages in the process, either at the initial or the final mixing stage. Samples taken at preliminary or later steps show that less than 20% of DHA added at the early stages disappeared prior to packaging for any recipe tested. Overall, our data indicate that most DHA included in RUTF is retained in the final product and that DHA is best retained when added at the latest manufacturing stage.
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Affiliation(s)
- Genevieve James
- Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX 78723, USA
| | - Kevin Stephenson
- Department of Medicine, Washington University, St. Louis, MO 63110, USA
| | | | | | - Hui Gyu Park
- Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX 78723, USA
| | - J. Thomas Brenna
- Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX 78723, USA
| | - Mark J. Manary
- Department of Pediatrics, Washington University, St. Louis, MO 63110, USA
- Project Peanut Butter, Freetown 47235, Sierra Leone
- Children’s Nutrition Research Center, USDA-Agricultural Research Service, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-(314)-454-2178
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Koroma AS, Ellie M, Bangura K, Iversen PO, Hendrixson DT, Stephenson K, Manary MJ. Supplementary feeding and infection control in pregnant adolescents-A secondary analysis of a randomized trial among malnourished women in Sierra Leone. Matern Child Nutr 2022; 19:e13456. [PMID: 36349973 PMCID: PMC9749587 DOI: 10.1111/mcn.13456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/11/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022]
Abstract
Undernutrition during pregnancy in adolescence confers a high risk of maternal morbidity and adverse birth outcomes, particularly in low-resource settings. In a secondary analysis, we hypothesized that younger undernourished pregnant adolescents (<18 years) would benefit more than undernourished pregnant adults (>20 years) from the intervention of supplementary food and anti-infective treatments. The original trial in Sierra Leone enrolled 236 younger adolescents (<18 years), 454 older adolescents (aged 18-19 years), and 741 adults (≥20 years), all with a mid-upper arm circumference ≤23 cm. Younger adolescents had lower final fundal height as well as smaller newborns (-0.3 kg; 95% confidence interval [CI], -0.3, -0.2; p < 0.001) and shorter newborns (-1.1 cm; 95% CI, -1.5, -0.7; p < 0.001) than adults. The intervention's effect varied significantly between maternal age groups: adults benefited more than younger adolescents with respect to newborn birth weight (difference in difference, 166 g; 95% CI, 26, 306; interaction p = 0.02), birth length (difference in difference, 7.4 mm; 95% CI, 0.1, 14.8; interaction p = 0.047), and risk for low birth weight (<2.5 kg) (interaction p = 0.019). The differences in response persisted despite adjustments for maternal anthropometry, the number of prior pregnancies, and human immunodeficiency virus status. Older adolescents similarly benefited more than younger adolescents, though differences did not reach statistical significance. In conclusion, newborns born to younger adolescent mothers had worse outcomes than those born to adult mothers, and adults and their newborns benefited more from the intervention than younger adolescents.
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Affiliation(s)
- Aminata S. Koroma
- Ministry of Health and SanitationRepublic of Sierra LeoneFreetownSierra Leone
| | - Mariama Ellie
- Ministry of Health and SanitationRepublic of Sierra LeoneFreetownSierra Leone
| | - Kadiatu Bangura
- Ministry of Health and SanitationRepublic of Sierra LeoneFreetownSierra Leone
| | - Per O. Iversen
- Department of NutritionUniversity of OsloOsloNorway,Department of HaematologyOslo University HospitalOsloNorway,Division of Human NutritionStellenbosch UniversityTygerbergSouth Africa
| | - David T. Hendrixson
- Department of PediatricsUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Kevin Stephenson
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Mark J. Manary
- Department of PediatricsWashington University School of Medicine in St. LouisSt. LouisMissouriUSA
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Baumberger K, Busby C, Mascarella A, McKinzie C, Stephenson K, Kam C. 208 Fat-soluble vitamin level trends after elexacaftor/tezacaftor/ivacaftor therapy. J Cyst Fibros 2022. [DOI: 10.1016/s1569-1993(22)00898-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Weller SA, Armstrong SR, Bailey S, Burnell HT, Burt EL, Cant NE, Cawthorne KR, Chester M, Choules JE, Coe NA, Coward L, Cox VL, Emery ER, Evans CP, Finn A, Halford CM, Hamblin KA, Harrison GV, Hartley MG, Hudson C, James B, Jones HE, Keyser E, Lonsdale CL, Marshall LE, Maule CE, Miles JA, Newstead SL, Nicholls M, Osborne C, Pearcy AS, Penny LD, Perrot R, Rachwal P, Robinson V, Rushton D, Stahl FM, Staplehurst SV, Stapleton HL, Steeds K, Stephenson K, Thompson IJ, Thwaite JE, Ulaeto DO, Waters N, Wills DJ, Wills ZS, Rees C, Hutley EJ. Development and operation of the defence COVID-19 lab as a SARS-CoV-2 diagnostic screening capability for UK military personnel. BMJ Mil Health 2022; 170:e002134. [PMID: 35878971 PMCID: PMC10958320 DOI: 10.1136/military-2022-002134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/03/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel. LABORATORY STRUCTURE AND RESOURCE The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists. LABORATORY RESULTS Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started. CONCLUSIONS Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.
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Affiliation(s)
- Simon A Weller
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - S R Armstrong
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - S Bailey
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - H T Burnell
- Operations Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, UK
| | - E L Burt
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - N E Cant
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - K R Cawthorne
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - M Chester
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - J E Choules
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - N A Coe
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - L Coward
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - V L Cox
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - E R Emery
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - C P Evans
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - A Finn
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - C M Halford
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - K A Hamblin
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - G V Harrison
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - M G Hartley
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - C Hudson
- Defence Pathology, Royal Centre for Defence Medicine, Birmingham, UK
| | - B James
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - H E Jones
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - E Keyser
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - C L Lonsdale
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - L E Marshall
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - C E Maule
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - J A Miles
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - S L Newstead
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - M Nicholls
- Defence Pathology, Royal Centre for Defence Medicine, Birmingham, UK
| | - C Osborne
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - A S Pearcy
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - L D Penny
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - R Perrot
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - P Rachwal
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - V Robinson
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - D Rushton
- Platform Systems Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, UK
| | - F M Stahl
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - S V Staplehurst
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - H L Stapleton
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - K Steeds
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - K Stephenson
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - I J Thompson
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - J E Thwaite
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - D O Ulaeto
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - N Waters
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - D J Wills
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - Z S Wills
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - C Rees
- CBR Division, Defence Science and Technology Laboratory Porton Down, Salisbury, UK
| | - E J Hutley
- Defence Pathology, Royal Centre for Defence Medicine, Birmingham, UK
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Stephenson K, O’Hara M, Holland C, Womble M, Jennings S, Weber Rawlins M, Elbin RJ. A-45 Clinical Considerations of Neuropsychologists for Treating Concussions. Arch Clin Neuropsychol 2022. [DOI: 10.1093/arclin/acac32.45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Purpose: The purpose of this study was to explore sex specific clinical considerations by neuropsychologists’ and general clinical considerations for the treatment of concussion. Methods: Fourteen clinical neuropsychologists who see concussion patients regularly (>1 case per week) were interviewed using a semi-structured guide that included a generic patient vignette. Participants were asked about clinical considerations that they faced while assessing, managing, and treating concussion. Two investigators independently coded the transcriptions and met to compare coding processes, definitions, and categories. A final codebook was developed in an iterative fashion and reapplied to all transcripts. Independent coding and member checks contributed to the trustworthiness of the data. Results: Participants’ clinical experience in treating concussion ranged from 1 to 40 years, and the sample was 64% female (9/14). Four major themes were identified, including patients’ sex considerations, sleep and napping, patient education and reassurance, and mental health considerations. Several participants (4/14; 29%) noted the lack of action-oriented clinical recommendations for previously documented sex differences (i.e., menstruation). There was a lack of uniformity in sleep and napping recommendations across the participants (e.g., permitting napping vs recommended nap-length). Participants noted that a large portion of their clinical time was spent educating and reassuring patients that concussion is treatable. Comorbid mental health considerations such as anxiety were a prevailing clinical concern across participants. Conclusions: The study revealed the need for better action-oriented clinical recommendations in consensus statements that address the four main themes of sex considerations, sleep and napping considerations, patient education and reassurance, and mental health considerations.
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Fleming PM, Stephenson K, Collick AS, Easton ZM. Targeting for nonpoint source pollution reduction: A synthesis of lessons learned, remaining challenges, and emerging opportunities. J Environ Manage 2022; 308:114649. [PMID: 35144063 DOI: 10.1016/j.jenvman.2022.114649] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/23/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
The ability to identify, target, and treat critical pollution source areas on a landscape is an ongoing challenge for water quality programs that seek to address nonpoint source (NPS) pollution. In this article, we develop a conceptual framework for targeting program design, and review recent experience with the implementation of targeting programs that corresponds with a wide range of program characteristics. Through this review, we emphasize that the complex and locally dependent nature of NPS generation and transport makes it impossible to define a narrow set of rules to guide targeting programs everywhere. Instead, we evaluate key features of NPS targeting in several different contexts, highlighting lessons learned from recent experience. This synthesis of targeting program design and implementation points toward several areas of opportunity for improved NPS policy, however more research is needed to systematically document changes in behavior and pollutant loads. The lack of monitoring data at refined scales presents a major obstacle to targeting program success. This paper synthesizes new opportunities and ongoing challenges for the implementation of targeting in NPS water quality programs.
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Affiliation(s)
- P M Fleming
- Department of Economics and Public Policy, Franklin and Marshall College, Lancaster, PA, 17604, USA.
| | - K Stephenson
- Department of Agricultural and Applied Economics, Virginia Tech, Blacksburg, VA, 24061, USA
| | - A S Collick
- Department of Agricultural Sciences, Morehead State University Morehead, KY, 40351, USA
| | - Z M Easton
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
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Leppänen JM, Butcher JW, Godbout C, Stephenson K, Hendrixson DT, Griswold S, Rogers BL, Webb P, Koroma AS, Manary MJ. Assessing infant cognition in field settings using eye-tracking: a pilot cohort trial in Sierra Leone. BMJ Open 2022; 12:e049783. [PMID: 35177442 PMCID: PMC8860005 DOI: 10.1136/bmjopen-2021-049783] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVES To investigate the feasibility of eye-tracking-based testing of the speed of visual orienting in malnourished young children at rural clinics in Sierra Leone. DESIGN Prospective dual cohort study nested in a cluster-randomised trial. SETTING 8 sites participating in a cluster-randomised trial of supplementary feeding for moderate acute malnutrition (MAM). PARTICIPANTS For the MAM cohort, all infants aged 7-11 months at the eight sites were enrolled, 138 altogether. For controls, a convenience sample of all non-malnourished infants aged 7-11 months at the same sites were eligible, 60 altogether. A sample of 30 adults at the sites also underwent eye-tracking tests as a further control. INTERVENTIONS Infants with MAM were provided with supplementary feeding. OUTCOME MEASURES The primary outcomes were feasibility and reliability of eye-tracking-based testing of saccadic reaction time (SRT). Feasibility was assessed by the percent of successful tests in the infants. Reliability was measured with intraclass correlation coefficients (ICCs). Secondary outcomes were mean SRT based on nutritional state as well as and changes in mean SRT after supplementary feeding of MAM children. RESULTS Infants exhibited consistent orienting to targets on a computer screen (>95% of valid trials). Mean SRTs had moderate stability within visits (ICCs 0.60-0.69) and across the 4-week test-retest interval (0.53) in infants; the adult control group had greater SRT stability (within visit ICC=0.92). MAM infants had a trend toward higher adjusted SRT at baseline (difference=12.4 ms, 95% CI -2 to 26.9, p=0.09) and improvement in SRT 4 weeks thereafter (difference=-14 ms, 95% CI -26.2 to -1.7, p=0.025) compared with age-matched controls. CONCLUSIONS The results demonstrate the feasibility of eye-tracking-based testing in a resource-poor field setting and suggest eye-tracking measures have utility in the detection of group level effects of supplementary feeding.
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Affiliation(s)
- Jukka M Leppänen
- Department of Psychology and Speech-Language Pathology, University of Turku, Turku, Finland
| | | | - Claire Godbout
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
| | - Kevin Stephenson
- Department of Internal Medicine, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
| | - D Taylor Hendrixson
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
| | - Stacy Griswold
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts, USA
| | - Beatrice Lorge Rogers
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts, USA
| | - Patrick Webb
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts, USA
| | - Aminata S Koroma
- Food and Nutrition, Sierra Leone Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Mark J Manary
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, Missouri, USA
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May T, de la Haye B, Nord G, Klatt K, Stephenson K, Adams S, Bollinger L, Hanchard N, Arning E, Bottiglieri T, Maleta K, Manary M, Jahoor F. One-carbon metabolism in children with marasmus and kwashiorkor. EBioMedicine 2022; 75:103791. [PMID: 35030356 PMCID: PMC8761690 DOI: 10.1016/j.ebiom.2021.103791] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 11/24/2021] [Accepted: 12/16/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Kwashiorkor is a childhood syndrome of edematous malnutrition. Its precise nutritional precipitants remain uncertain despite nine decades of study. Remarkably, kwashiorkor's disturbances resemble the effects of experimental diets that are deficient in one-carbon nutrients. This similarity suggests that kwashiorkor may represent a nutritionally mediated syndrome of acute one-carbon metabolism dysfunction. Here we report findings from a cross-sectional exploration of serum one-carbon metabolites in Malawian children. METHODS Blood was collected from children aged 12-60 months before nutritional rehabilitation: kwashiorkor (N = 94), marasmic-kwashiorkor (N = 43) marasmus (N = 118), moderate acute malnutrition (N = 56) and controls (N = 46). Serum concentrations of 16 one-carbon metabolites were quantified using LC/MS techniques, and then compared across participant groups. FINDINGS Twelve of 16 measured one-carbon metabolites differed significantly between participant groups. Measured outputs of one-carbon metabolism, asymmetric dimethylarginine (ADMA) and cysteine, were lower in marasmic-kwashiorkor (median µmol/L (± SD): 0·549 (± 0·217) P = 0·00045 & 90 (± 40) P < 0·0001, respectively) and kwashiorkor (0·557 (± 0·195) P < 0·0001 & 115 (± 50) P < 0·0001), relative to marasmus (0·698 (± 0·212) & 153 (± 42)). ADMA and cysteine were well correlated with methionine in both kwashiorkor and marasmic-kwashiorkor. INTERPRETATION Kwashiorkor and marasmic-kwashiorkor were distinguished by evidence of one-carbon metabolism dysfunction. Correlative observations suggest that methionine deficiency drives this dysfunction, which is implicated in the syndrome's pathogenesis. The hypothesis that kwashiorkor can be prevented by fortifying low quality diets with methionine, along with nutrients that support efficient methionine use, such as choline, requires further investigation. FUNDING The Hickey Family Foundation, the American College of Gastroenterology, the NICHD, and the USDA/ARS.
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Affiliation(s)
- Thaddaeus May
- Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston TX, USA.
| | | | | | - Kevin Klatt
- Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston TX, USA,Center for Precision Environmental Health, Baylor College of Medicine
| | | | | | - Lucy Bollinger
- Washington University in St. Louis School of Medicine, USA
| | - Neil Hanchard
- National Institutes of Health, USA,National Human Genome Research Institute, Nationl Institutes of Health
| | - Erland Arning
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott and White Research Institute
| | - Teodoro Bottiglieri
- Center of Metabolomics, Institute of Metabolic Disease, Baylor Scott and White Research Institute
| | | | - Mark Manary
- Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston TX, USA,The University of Malawi College of Medicine, Malawi,Washington University in St. Louis School of Medicine, USA
| | - Farook Jahoor
- Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston TX, USA
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10
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Stephenson K, Callaghan-Gillespie M, Maleta K, Nkhoma M, George M, Park HG, Lee R, Humphries-Cuff I, Lacombe RJS, Wegner DR, Canfield RL, Brenna JT, Manary MJ. Low linoleic acid foods with added DHA given to Malawian children with severe acute malnutrition improve cognition: a randomized, triple-blinded, controlled clinical trial. Am J Clin Nutr 2021; 115:1322-1333. [PMID: 34726694 PMCID: PMC9071416 DOI: 10.1093/ajcn/nqab363] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 07/16/2021] [Accepted: 10/28/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND There is concern that the PUFA composition of ready-to-use therapeutic food (RUTF) for the treatment of severe acute malnutrition (SAM) is suboptimal for neurocognitive recovery. OBJECTIVES We tested the hypothesis that RUTF made with reduced amounts of linoleic acid, achieved using high-oleic (HO) peanuts without added DHA (HO-RUTF) or with added DHA (DHA-HO-RUTF), improves cognition when compared with standard RUTF (S-RUTF). METHODS A triple-blind, randomized, controlled clinical feeding trial was conducted among children with uncomplicated SAM in Malawi with 3 types of RUTF: DHA-HO-RUTF, HO-RUTF, and S-RUTF. The primary outcomes, measured in a subset of subjects, were the Malawi Developmental Assessment Tool (MDAT) global z-score and a modified Willatts problem-solving assessment (PSA) intention score for 3 standardized problems, measured 6 mo and immediately after completing RUTF therapy, respectively. MDAT domain z-scores, plasma fatty acid content, anthropometry, and eye tracking were secondary outcomes. Comparisons were made between the novel PUFA RUTFs and S-RUTF. RESULTS Among the 2565 SAM children enrolled, mean global MDAT z-scores were -0.69 ± 1.19 and -0.88 ± 1.27 for children receiving DHA-HO-RUTF and S-RUTF, respectively (difference 0.19, 95% CI: 0.01, 0.38). Children receiving DHA-HO-RUTF had higher gross motor and social domain z-scores than those receiving S-RUTF. The PSA problem 3 scores did not differ by dietary group (OR: 0.92, 95% CI: 0.67, 1.26 for DHA-HO-RUTF). After 4 wk of treatment, plasma phospholipid EPA and α-linolenic acid were greater in children consuming DHA-HO-RUTF or HO-RUTF when compared with S-RUTF (for all 4 comparisons P values < 0.001), but only plasma DHA was greater in DHA-HO-RUTF than S-RUTF (P < 0.001). CONCLUSIONS Treatment of uncomplicated SAM with DHA-HO-RUTF resulted in an improved MDAT score, conferring a cognitive benefit 6 mo after completing diet therapy. This treatment should be explored in operational settings. This trial was registered at clinicaltrials.gov as NCT03094247.
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Affiliation(s)
- Kevin Stephenson
- Department of Medicine, Washington University, St.
Louis, MO, USA
| | | | - Kenneth Maleta
- Department of Public Health, School of Public Health & Family Medicine,
Kamuzu University of Health Sciences, Blantyre,
Malawi
| | - Minyanga Nkhoma
- Department of Public Health, School of Public Health & Family Medicine,
Kamuzu University of Health Sciences, Blantyre,
Malawi
| | - Matthews George
- Department of Public Health, School of Public Health & Family Medicine,
Kamuzu University of Health Sciences, Blantyre,
Malawi
| | - Hui Gyu Park
- Department of Pediatrics, University of Texas at Austin,
Austin, TX, USA
| | - Reginald Lee
- Department of Pediatrics, Washington University,
St. Louis, MO, USA
| | | | - R J Scott Lacombe
- Department of Pediatrics, University of Texas at Austin,
Austin, TX, USA
| | - Donna R Wegner
- Department of Pediatrics, Washington University,
St. Louis, MO, USA
| | - Richard L Canfield
- Department of Pediatrics, University of Texas at Austin,
Austin, TX, USA
| | - J Thomas Brenna
- Department of Pediatrics, University of Texas at Austin,
Austin, TX, USA,Division of Nutritional Sciences, Cornell University,
Ithaca, NY, USA
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11
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McGray AJR, Eppolito C, Miliotto A, Singel KL, Stephenson K, Lugade A, Segal BH, Keler T, Webster G, Lichty B, Kozbor D, Odunsi K. A prime/boost vaccine platform efficiently identifies CD27 agonism and depletion of myeloid-derived suppressor cells as therapies that rationally combine with checkpoint blockade in ovarian cancer. Cancer Immunol Immunother 2021; 70:3451-3460. [PMID: 33880648 PMCID: PMC8057655 DOI: 10.1007/s00262-021-02936-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/31/2021] [Indexed: 12/30/2022]
Abstract
Cancer immunotherapies have generated remarkable clinical responses for some patients with advanced/metastatic disease, prompting exploration of rational combination therapies to bolster anti-tumor immunity in patients with limited response or those who experience tumor progression following an initial response to immunotherapy. In contrast to other tumor indications, objective response rates to single-agent PD-1/PD-L1 blockade in ovarian cancer are limited, suggesting a need to identify combinatorial approaches that lead to tumor regression in a setting where checkpoint blockade alone is ineffective. Using a pre-clinical model of aggressive intraperitoneal ovarian cancer, we have previously reported on a heterologous prime/boost cancer vaccine that elicits robust anti-tumor immunity, prolongs survival of tumor-bearing mice, and which is further improved when combined with checkpoint blockade. As tumor control in this model is CD8 + T cell dependent, we reasoned that the prime/boost vaccine platform could be used to explore additional treatment combinations intended to bolster the effects of CD8 + T cells. Using whole tumor transcriptomic data, we identified candidate therapeutic targets anticipated to rationally combine with prime/boost vaccination. In the context of a highly effective cancer vaccine, CD27 agonism or antibody-mediated depletion of granulocytic cells each modestly increased tumor control following vaccination, with anti-PD-1 therapy further improving treatment efficacy. These findings support the use of immunotherapies with well-defined mechanisms(s) of action as a valuable platform for identifying candidate combination approaches for further therapeutic testing in ovarian cancer.
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Affiliation(s)
- A J R McGray
- Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263, USA.
| | - C Eppolito
- Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263, USA
| | - A Miliotto
- Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263, USA
| | - K L Singel
- Department of Immunology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
- Office of Evaluation, Performance, and Reporting, National Institutes of Health, Bethesda, MD, USA
| | - K Stephenson
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
- Turnstone Biologics, Ottawa, ON, Canada
| | - A Lugade
- Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263, USA
| | - B H Segal
- Department of Immunology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
- Department of Internal Medicine, Roswell Park Comprehensive Cancer Center and Jacobs School of Medicine and Biomedical Sciences, University At Buffalo, Buffalo, NY, USA
| | - T Keler
- Celldex Therapeutics, Hampton, NJ, USA
| | - G Webster
- Innate Immunotherapeutics, Auckland, New Zealand
| | - B Lichty
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
| | - D Kozbor
- Department of Immunology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - K Odunsi
- Center for Immunotherapy, Roswell Park Comprehensive Cancer Center, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263, USA.
- University of Chicago Comprehensive Cancer Center, 5841 South Maryland Avenue, MC1140, Chicago, IL, 60637, USA.
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12
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Stephenson K, Womble MN, Elbin RJ. A-41 Exploring the Influence of Referral Source on State Anxiety Levels of Concussed Patients. Arch Clin Neuropsychol 2020. [DOI: 10.1093/arclin/acaa036.41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Objective
To explore the influence of referral source on state anxiety in concussed athletes.
Method
One hundred thirty athletes (mean age = 16.46, SD = 1.93 yrs; 42% female) seeking care for a concussion at a specialty clinic within 30 days of injury (M = 8.83, SD = 6.12 days) were enrolled in the study. Demographic (e.g., age, sex, and history of anxiety) and referral source (e.g., emergency department/urgent care, primary care/pediatrician, and athletic trainer) information were collected, and the State-Trait Anxiety Inventory (STAI) was administered to all participants. A one-way analysis of variance (ANOVA) was conducted to compare STAI scores between referral groups, and a logistic regression (LR) was used to assess the relationship between referral sources and patients with and without clinical levels of state anxiety (STAI > 40). Statistical significance for all analyses was (p < .05).
Results
Approximately 25% (32/130) of patients reported a history of anxiety, and 46% (60/130) scored above clinical cutoffs for clinical anxiety. The referral groups did not differ on STAI scores (F(3, 130) = 1.12, p = .34), and the LR was not significant, (χ2(2, N = 130) = 3.75, p = 0.15).
Conclusions
History of anxiety was highly correlated with state anxiety at the first clinical visit; however, patients referred from different medical sources did not differ on clinical levels of anxiety at the first clinical visit following concussion.
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13
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Womble MN, Stephenson K, Gustman B, Castor E, Kontos AP, Schatz P, Elbin RJ. A-48 Athletes that self-report no physical activity/rest are more likely to exhibit clinical levels of state anxiety following concussion. Arch Clin Neuropsychol 2020. [DOI: 10.1093/arclin/acaa036.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Objective
To investigate the influence of self-reported physical activity (PA) on state anxiety in athletes with concussion
Method
Participants were 230 athletes (mean age = 16.46, SD = 1.94; 43% female) seeking care for a concussion at a specialty clinic within 30 days of injury (M = 8.83, SD = 6.12 days). Demographic data were collected during the clinical interview: age, sex, and history of concussion, migraine, learning disability, attention deficit hyperactivity disorder, anxiety, and depression. Patients completed the State-Trait Anxiety Inventory (STAI) and self-reported current levels of PA; 113 participants reported rest or no physical activity (REST) and 117 reported at least minimal PA (ACTIVE). The groups were compared on demographic variables to ensure group equivalence. Independent samples t-test examined differences between groups on state anxiety scores and a chi-square with odds ratios (ORs) examined the relationship between PA groups and clinical levels of state anxiety (STAI > 40). Statistical significance for all analyses was (p < .05).
Results
The groups were similar on all demographic variables (p > .05). The NO PA/REST group exhibited significantly higher state anxiety scores at first clinic visit than the PA group (t (228) = 2.82, p = .005), and the NO PA/REST group was 2.26 times more likely to exhibit clinical levels of state anxiety than the PA group at first clinic visit (χ2 (1, N = 230) = 9.16, p = .002).
Conclusions
Anxiety that is secondary to concussive injury could be mitigated with physical activity. Healthcare providers should encourage individuals with concussion to engage in physical activity during recovery.
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14
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Ordiz MI, Janssen S, Humphrey G, Ackermann G, Stephenson K, Agapova S, Divala O, Kaimila Y, Maleta K, Zhong C, Knight R, Trehan I, Tarr PI, Rusconi B, Manary MJ. The effect of legume supplementation on the gut microbiota in rural Malawian infants aged 6 to 12 months. Am J Clin Nutr 2020; 111:884-892. [PMID: 32047925 PMCID: PMC8287943 DOI: 10.1093/ajcn/nqaa011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 09/14/2019] [Accepted: 01/21/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Common bean and cowpea contain about 25% protein and 25% fiber, and are recommended as complementary foods in sub-Saharan Africa. OBJECTIVE The objective of this study was to determine if a daily legume supplement given to Malawian infants aged 6 to 12 mo alters the 16S configuration of the fecal microbiota as read out by amplicon sequence variants (ASVs). METHODS This study was conducted within the context of a randomized, double-blind, controlled clinical trial to assess whether cowpea or common bean supplementation reduced intestinal permeability or increased linear growth. There were 2 village clusters in which the study was conducted. Fresh stool collections were flash frozen from 236 infants at ≤6 time points. The stools were sequenced using Earth Microbiome project protocols and data were processed using Qiime and Qiita, open-source, validated software packages. α-diversity was measured using the Faith's test. The 16S configuration was characterized by determining the weighted UniFrac distances of the ASVs and comparing them using permutational multivariate ANOVA. RESULTS Among the 1249 samples analyzed, the α-diversity of the fecal microbiome was unchanged among subjects after initiation of legume supplementation. Neither cowpea nor common bean altered the overall 16S configuration at any age. The 16S configuration differed between children with adequate and poor linear growth aged from 6 to 9 mo, but no specific ASVs differed in relative abundance. The 16S configuration differed between children with normal and abnormal intestinal permeability at 9 mo, but no specific ASVs differed in relative abundance. Among categorical characteristics of the population associated with different 16S configurations, village cluster was most pronounced. CONCLUSION Legume supplementation in breastfed, rural African infants did not affect the structure of the gut microbial communities until the children were aged 9 mo. This trial was registered at clinicaltrials.gov as NCT02472262.
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Affiliation(s)
- M Isabel Ordiz
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
| | - Stefan Janssen
- Department of Pediatrics, University of California San Diego, La
Jolla, CA, USA
| | - Greg Humphrey
- Department of Pediatrics, University of California San Diego, La
Jolla, CA, USA
| | - Gail Ackermann
- Department of Pediatrics, University of California San Diego, La
Jolla, CA, USA
| | - Kevin Stephenson
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
| | - Sophia Agapova
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
| | - Oscar Divala
- Department of Community Health, College of Medicine, University of
Malawi, Malawi
| | - Yankho Kaimila
- Department of Community Health, College of Medicine, University of
Malawi, Malawi
| | - Ken Maleta
- Department of Community Health, College of Medicine, University of
Malawi, Malawi
| | - Caroline Zhong
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, La
Jolla, CA, USA
- Department of Computer Science and Engineering, University of
California San Diego, La Jolla, CA, USA
- Department of Bioengineering, University of California San Diego,
La Jolla, CA, USA
- Center for Microbiome Innovation, University of California San
Diego, La Jolla, CA, USA
| | - Indi Trehan
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
- Department of Paediatrics and Child Health, University of Malawi,
Blantyre, Malawi
| | - Phillip I Tarr
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
| | - Brigida Rusconi
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
| | - Mark J Manary
- Department of Pediatrics, Washington University at St. Louis, St.
Louis, MO, USA
- Department of Community Health, College of Medicine, University of
Malawi, Malawi
- USDA/Agricultural Research Service Children's Nutrition Research
Center, Houston, TX, USA
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15
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Venker BT, Dunn JP, Stephenson K. The Rising Cost of Diabetes: Can DiRECT Tip the Scales? Obesity (Silver Spring) 2018; 26:1866-1867. [PMID: 30417975 DOI: 10.1002/oby.22349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/11/2018] [Accepted: 09/11/2018] [Indexed: 01/22/2023]
Abstract
The cost of treating diabetes mellitus has risen sharply in recent years because of an increasing number of patients with type 2 diabetes and obesity and a rapidly expanding repertoire of expensive nongeneric medications. Despite the call for a new treatment paradigm by the American Diabetes Association to mitigate this cost, recent Medicare Part D expenditure data show that this call remains unanswered. The Diabetes Remission Clinical Trial, published in The Lancet, adds support to a different path, demonstrating success with intensive lifestyle intervention followed by structured support for long-term weight loss maintenance. Nearly half of patients enrolled were able to achieve remission of their diabetes with hemoglobin A1c < 6.5% and an improvement of their quality of life. Although only from one trial, and of limited duration, these results should provide optimism for providers and patients alike and support future work toward an evidence base for non-medication-based management of diabetes.
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Affiliation(s)
- Brett T Venker
- Department of Pharmacy, VA St. Louis Health Care System, St. Louis, Missouri, USA
| | - Julia P Dunn
- Department of Endocrinology, VA St. Louis Health Care System, St. Louis, Missouri, USA
| | - Kevin Stephenson
- Department of Medicine, University of Washington, Seattle, Washington, USA
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16
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Ayad T, Stephenson K, A L Smit D, Ben-Ari O, Késmárszky R, Lechien JR, Sobol S, Meller C, Sargi Z, Maunsell R, De Siati RD, Jia H, Krishnan V, North H, Eter EG, Metwaly O, Peer S, Teissier N, Sowerby L, Hong P, Fakhry N. Young Otolaryngologists of International Federation of Oto-rhino-laryngological Societies (YO-IFOS) committees. Eur Ann Otorhinolaryngol Head Neck Dis 2018; 135:S61-S65. [PMID: 30174261 DOI: 10.1016/j.anorl.2018.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 11/30/2022]
Affiliation(s)
- T Ayad
- Centre Hospitalier de l'Université de Montréal, Montreal, Canada.
| | - K Stephenson
- Birmingham Children's Hospital, Birmingham, United Kingdom
| | - D A L Smit
- University Medical Centre Utrecht, Utrecht, The Netherlands
| | - O Ben-Ari
- Tel Aviv Sourasky Medical Center, affiliated to Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - J R Lechien
- Centre Hospitalier Universitaire de Bruxelles, Site Saint-Pierre, Bruxelles, Belgium
| | - S Sobol
- University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - C Meller
- Prince of Wales and Sydney Hospitals, Sydney, Australia
| | - Z Sargi
- Sylvester Comprehensive Cancer Center, University of Miami, Miami, Fl, USA
| | - R Maunsell
- Setor de Otorrinolaringologia Pediátrica, FCM-UNICAMP, Campinas, Brazil
| | - R D De Siati
- Université Catholique de Louvain, Cliniques Universitaires Saint Luc, Brussels, Belgium
| | - H Jia
- Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - V Krishnan
- Madras ENT Research Foundation, Raja Annamalaipuram, Chennai, India
| | - H North
- Westmead Hospital, Sydney, Australia
| | - E G Eter
- Saint joseph University, School of Medecine, Beirut, Lebanon
| | - O Metwaly
- Kasr Alainy School of Medicine, Cairo University, Cairo, Egypt
| | - S Peer
- Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | | | - L Sowerby
- St. Joseph's Healthcare, Western University, London, Canada
| | - P Hong
- IWK Health Centre, Division of Otolaryngology-Head and Neck Surgery, Dalhousie University, Halifax, Nova Scotia
| | - N Fakhry
- Hôpital de la Conception, Marseille, France
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17
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Fournier I, Stephenson K, Fakhry N, Jia H, Sampathkumar R, Lechien JR, Melkane AE, Bahgat AY, De Carvalho Lopes K, Kennel T, Teissier N, Ayad T. Barriers to research among residents in Otolaryngology - Head & Neck Surgery around the world. Eur Ann Otorhinolaryngol Head Neck Dis 2018; 136:S3-S7. [PMID: 30143399 DOI: 10.1016/j.anorl.2018.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/16/2018] [Accepted: 06/22/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To document the challenges faced by residents in Otolaryngology - Head & Neck Surgery (OTL-HNS) around the world to successfully complete research projects. The second objective is to assess if the challenges are uniform worldwide. METHODS A survey was sent to all OTL-HNS under 45 years old from the 2017 IFOS meeting. This survey was conducted by the YO-IFOS group (Young Otolaryngologists of the International Federation of Otolaryngological Societies). Data was collected for a period of 1 month. Demographic characteristics, information regarding research projects conducted and data concerning perceived barriers to completion of research projects were collected. RESULTS Among the 2787 attendees, 928 responded to the survey (response rate=33.3%). Of these 928 answers, 267 responses were from residents/interns in OTL-HNS, while 635 responses were from certified otolaryngologists. The three most frequent obstacles to conducting research projects for trainees were limited dedicated time (64%), insufficient financial resources (55%) and lack of education in research (45%). There was no statistical difference in these barriers among the different countries (P>0.05). CONCLUSION This is the first international study that provides insight on trainee's challenges to conduct research projects during residency. Despite the notion that research is essential for generating new knowledge to guide patient care, many residents fail to successfully incorporate research in their surgical curriculum. These obstacles must be addressed by Otolaryngology - Head & Neck Surgery programs in order to facilitate and support resident's research.
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Affiliation(s)
- I Fournier
- School of medecine, Université de Montréal, Montreal, Canada
| | - K Stephenson
- Birmingham Children's Hospital, Birmingham, United Kingdom
| | - N Fakhry
- Hôpital de la Conception, Marseille, France
| | - H Jia
- Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | | | - J R Lechien
- CHU de Bruxelles, site CHU Saint-Pierre, Brusells, Belgium
| | - A E Melkane
- Hotel-Dieu de France Hospital, Saint-Joseph University, Beirut, Lebanon
| | - A Y Bahgat
- Lecturer of Otorhinolaryngology and consultant of sleep Surgery, Alexandria University, Egypt
| | | | - T Kennel
- Université de Montpellier, hôpital universitaire Gui-de-Chauliac, CHRU de Montpellier, Montpellier, France
| | | | - T Ayad
- Centre hospitalier de l'université de Montréal, Montreal, Canada.
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18
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Ordiz MI, Davitt C, Stephenson K, Agapova S, Divala O, Shaikh N, Manary MJ. EB 2017 Article: Interpretation of the lactulose:mannitol test in rural Malawian children at risk for perturbations in intestinal permeability. Exp Biol Med (Maywood) 2018; 243:677-683. [PMID: 29597877 DOI: 10.1177/1535370218768508] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The dual sugar absorption test, specifically the lactulose:mannitol test, is used to assess gut health. Lactulose absorption is said to represent gut damage and mannitol absorption is used as a measure of normal small bowel function and serves as normalizing factor for lactulose. A underappreciated limitation of this common understanding of the lactulose:mannitol test is that mannitol is not absorbed to any substantial extent by a transcellular process. Additionally, this interpretation of lactulose:mannitol is not consistent with current understanding of paracellular pathways, where three pathway types exist: pore, leak, and unrestricted. Pore and leak pathways are regulated biological constructions of the small bowel barrier, and unrestricted pathways represent micropathological damage. We analyzed 2334 lactulose:mannitol measurements rigorously collected from 622 young rural Malawian children at high risk for poor gut health in light of the pathway model. An alternative method of normalizing for gut length utilizing autopsy data is described. In our population, absorbed lactulose and mannitol are strongly correlated, r = 0.68 P <0.0001, suggesting lactulose and mannitol are traversing the gut barrier via the same pathways. Considering measurements where pore pathways predominate, mannitol flux is about 14 times that of lactulose. As more leak pathways are present, this differential flux mannitol:lactulose falls to 8:1 and when increased numbers of unrestricted pathways are present, the differential flux of mannitol:lactulose is 6:1. There was no substantial correlation between the lactulose:mannitol and linear growth. Given that mannitol will always pass through a given pathway at a rate at least equal to that of lactulose, and lactulose absorption is a composite measure of flux through both physiologic and pathologic pathways, we question the utility of the lactulose:mannitol test. We suggest using lactulose alone is as informative as lactulose:mannitol in a sugar absorption testing in subclinical gut inflammation. Impact statement Our work integrates the standard interpretation of the lactulose:mannitol test (L:M), with mechanistic insight of intestinal permeability. There are three paracellular pathways in the gut epithelium; pore, leak, and unrestricted. Using thousands of L:M measurements from rural Malawian children at risk for increased intestinal permeability, we predict the differential flux of L and M through the pathways. Our findings challenge the traditional notions that little L is absorbed through a normal epithelial barrier and that M is a normalizing factor for L. Our observations are consistent with pore pathways allowing only M to pass. And that substantial amounts of L and M pass through leak pathways which are normal, regulated, cell-junctional adaptations. So M is a composite measure of all pathways, and L is not a measure solely of pathologic gut damage. Using L alone as a probe will yield more information about gut health than L:M.
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Affiliation(s)
- M Isabel Ordiz
- 1 Department of Pediatrics, Washington University at Saint Louis, St. Louis, MO 63110, USA
| | - Caroline Davitt
- 1 Department of Pediatrics, Washington University at Saint Louis, St. Louis, MO 63110, USA
| | - Kevin Stephenson
- 1 Department of Pediatrics, Washington University at Saint Louis, St. Louis, MO 63110, USA
| | - Sophia Agapova
- 1 Department of Pediatrics, Washington University at Saint Louis, St. Louis, MO 63110, USA
| | - Oscar Divala
- 2 School of Public Health and Family Medicine, University of Malawi, Blantyre 3, Malawi
| | - Nurmohammad Shaikh
- 1 Department of Pediatrics, Washington University at Saint Louis, St. Louis, MO 63110, USA
| | - Mark J Manary
- 1 Department of Pediatrics, Washington University at Saint Louis, St. Louis, MO 63110, USA.,2 School of Public Health and Family Medicine, University of Malawi, Blantyre 3, Malawi.,3 Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030, USA
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19
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Ordiz MI, Stephenson K, Agapova S, Wylie KM, Maleta K, Martin J, Trehan I, Tarr PI, Manary MJ. Environmental Enteric Dysfunction and the Fecal Microbiota in Malawian Children. Am J Trop Med Hyg 2016; 96:473-476. [PMID: 27956653 DOI: 10.4269/ajtmh.16-0617] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 10/23/2016] [Indexed: 01/18/2023] Open
Abstract
Environmental enteric dysfunction (EED) is often measured with a dual sugar absorption test and implicated as a causative factor in childhood stunting. Disturbances in the gut microbiota are hypothesized to be a mechanism by which EED is exacerbated, although this supposition lacks support. We performed 16S ribosomal RNA gene sequencing of fecal samples from 81 rural Malawian children with varying degrees of EED to determine which bacterial taxa were associated with EED. At the phyla level, Proteobacteria abundance is reduced with severe EED. Among bacterial genera, Megasphaera, Mitsuokella, and Sutterella were higher in EED and Succinivibrio, Klebsiella, and Clostridium_XI were lower in EED. Bacterial diversity did not vary with the extent of EED. Though EED is a condition that is typically believed to affect the proximal small bowel, and our focus was on stool, our data do suggest that there are intraluminal microbial differences that reflect, or plausibly lead to, EED.
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Affiliation(s)
- M Isabel Ordiz
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Kevin Stephenson
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Sophia Agapova
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Kristine M Wylie
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.,The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri
| | - Ken Maleta
- Department of Community Health, College of Medicine, University of Malawi, Malawi, Africa
| | - John Martin
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri
| | - Indi Trehan
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.,College of Medicine, University of Malawi, Malawi, Africa
| | - Phillip I Tarr
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Mark J Manary
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri. .,School of Public Health and Family Medicine, University of Malawi, Blantyre, Malawi.,United States Department of Agriculture/Agricultural Research Service Childrens Nutrition Research Center, Houston, Texas
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20
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Lin SY, Lachowsky NJ, Hull M, Rich A, Cui Z, Sereda P, Jollimore J, Stephenson K, Thumath M, Montaner J, Roth EA, Hogg RS, Moore DM. Awareness and use of nonoccupational post-exposure prophylaxis among men who have sex with men in Vancouver, Canada. HIV Med 2016; 17:662-73. [PMID: 27477994 DOI: 10.1111/hiv.12369] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Nonoccupational post-exposure prophylaxis (nPEP) is a strategy to reduce the risk of HIV infection in those with high-risk exposure. This study characterized nPEP awareness among gay, bisexual and other men who have sex with men (MSM) in Metro Vancouver, British Columbia, Canada after a pilot nPEP programme established in 2012. METHODS Momentum Health Study participants were MSM aged ≥16 years recruited via respondent-driven sampling (RDS) who completed a computer-assisted self-interview. Stratifying patients by HIV status, we used multivariable logistic regression with backward selection to identify factors associated with nPEP awareness. All analyses were RDS-adjusted. RESULTS A total of 51.9% (112 of 173) of HIV-positive and 48.5% (272 of 500) of HIV-negative participants had heard of nPEP. Only 3% (five of 106) of HIV-negative participants who reported recent high-risk sex used nPEP. Generally, nPEP awareness was higher for participants who engaged in sexual activities with increased HIV transmission potential. Factors associated with greater awareness among HIV-negative participants included recent alcohol use, higher communal sexual altruism, previous sexually transmitted infection diagnosis, and greater perceived condom use self-efficacy. Other factors associated with greater awareness among HIV-negative participants included white race/ethnicity, gay sexual identity, more formal education, lower personal sexual altruism, and Vancouver residence. Greater nPEP awareness among HIV-positive participants was associated with greater perceived agency to ask sexual partners' HIV status and more frequently reporting doing so, a higher number of lifetime receptive sex partners, and greater access to condoms. CONCLUSIONS Following implementation of an nPEP pilot programme, nPEP awareness among HIV-negative MSM was 51% and use was 3%. These data support the need to expand access to and actively promote nPEP services.
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Affiliation(s)
- S Y Lin
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - N J Lachowsky
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - M Hull
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - A Rich
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - Z Cui
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - P Sereda
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada
| | - J Jollimore
- Health Initiative for Men, Vancouver, BC, Canada
| | | | - M Thumath
- Faculty of Nursing, University of British Columbia, Vancouver, BC, Canada.,British Columbia Centre for Disease Control, Vancouver, BC, Canada
| | - Jsg Montaner
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - E A Roth
- Department of Anthropology, Faculty of Social Sciences, University of Victoria, Victoria, BC, Canada.,Centre for Addictions Research BC, Victoria, BC, Canada
| | - R S Hogg
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - D M Moore
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,British Columbia Centre for Disease Control, Vancouver, BC, Canada
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Benzoni N, Korpe P, Thakwalakwa C, Maleta K, Stephenson K, Manary M, Manary M. Plasma endotoxin core antibody concentration and linear growth are unrelated in rural Malawian children aged 2-5 years. BMC Res Notes 2015; 8:258. [PMID: 26103960 PMCID: PMC4477295 DOI: 10.1186/s13104-015-1238-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 06/17/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Environmental enteropathy is subclinical inflammation of the upper gastrointestinal tract associated with reduced linear growth in developing countries. Usually investigators have used biopsy or a dual sugar absorption test to assess environmental enteropathy. Such tests are time and resource intensive, restricting their utility as screening methods. Serum endotoxin core antibody (EndoCab) concentration is a potential indicator of intestinal inflammation and integrity, and thus may be useful to predict environmental enteropathy. We analyzed the association of serum EndoCab levels versus linear growth and lactulose-mannitol assay results in 2-5 year old rural Malawian children. METHODS This was an observational study of 388 rural, asymptomatic Malawian children who had anthropometric measurements taken at least every 3 months since birth. In June and July 2011, dual sugar permeability tests were performed and serum samples were drawn for EndoCab assays. Pearson correlation, Student's t test and multivariable linear regression were used to compare ln EndoCab concentrations with height-for-age z scores (HAZ) at time of sampling and 3 months later. Identical analysis was also performed for ln EndoCab versus measurements from dual sugar permeability testing performed in conjunction with serum sampling. In a subgroup of children with anthropometric data in the months prior to serum sampling, Pearson correlation was used to estimate the relationship between ln EndoCab and recent linear growth. RESULTS Ln EndoCab concentrations were not correlated with HAZ at time of measurement (B = -0.078, P = 0.14) nor change in HAZ over the subsequent 3 months HAZ (B = -0.018, P = 0.27). EndoCab concentration was not associated with %lactulose excretion (B < 0.001, P = 0.98) nor the lactulose:mannitol ratio (B = 0.021, P = 0.62). Subgroup analysis also did not reveal any significant association between EndoCab and recent growth. CONCLUSION EndoCab titers were not correlated with measurements of growth or intestinal permeability in rural pre-school aged Malawian children.
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Affiliation(s)
- Nicole Benzoni
- Department of Pediatrics, Washington University, St. Louis, MO, 63110, USA.
| | - Poonum Korpe
- School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
| | - Chrissie Thakwalakwa
- Department of Community Health, College of Medicine, University of Malawi, Blantyre, Malawi.
| | - Ken Maleta
- Department of Community Health, College of Medicine, University of Malawi, Blantyre, Malawi.
| | - Kevin Stephenson
- College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Micah Manary
- School of Medicine, University of California, San Diego, San Diego, CA, USA.
| | - Mark Manary
- Department of Pediatrics, Washington University, St. Louis, MO, 63110, USA. .,Department of Pediatrics, St. Louis Children's Hospital, One Children's Place, St. Louis, MO, 63110, USA.
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22
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Briggs S, Stephenson K, Holliday J, Peckham R, Arthur D, Papanikolaou M, Butt A, Pickford A, Pilkington G, Fillmore HL. O4.03 * GLIOBLASTOMA STIMULATED ANGIOGENESIS IS MEDIATED BY MMP-3 ACTIVATED MMP-1 VIA BRAIN ENDOTHELIAL CELL ASSOCIATED PROTEASE ACTIVATED RECEPTOR 1 (PAR1) AND IS ENHANCED UNDER HYPOXIC CONDITIONS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou174.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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23
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Cheng S, Stephenson K, Jain A, Horowitz D, Yan S, Wang T, Chao K, Hei T. The Effects of β-Adrenergic Antagonists on Radiation Therapy for Locally Advanced Lung Cancers. Int J Radiat Oncol Biol Phys 2014. [DOI: 10.1016/j.ijrobp.2014.05.785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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24
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Barrable B, Thorogood N, Noonan V, Joshi P, Stephenson K, Kwon B, Dvorak M. P260 A Model For Bridging The Translational Valley Of Death In Spinal Cord Injury. BMJ Qual Saf 2013. [DOI: 10.1136/bmjqs-2013-002293.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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25
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Franano F, Sifuentes X, Stephenson K, Brunell S, Ainsworth B. Blockstent deployment results in immediate vascular occlusion. J Vasc Interv Radiol 2013. [DOI: 10.1016/j.jvir.2013.01.424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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26
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Franano F, Sifuentes X, Stephenson K, Brunell S, Ainsworth B. Ballstent deployment results in immediate cerebral aneurysm occlusion. J Vasc Interv Radiol 2013. [DOI: 10.1016/j.jvir.2013.01.430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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27
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Sohl S, Stanbery K, Tooze J, Lentz S, Stephenson K, Danhauer S. P05.72. Survey to assess the feasibility of providing a brief yoga skills training to improve outcomes of gynecologic cancer surgery. BMC Complement Altern Med 2012. [PMCID: PMC3373772 DOI: 10.1186/1472-6882-12-s1-p432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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28
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Stephenson K, Potter V. 6039 POSTER Pulmonary Metastatectomy for Colorectal Cancer – a Retrospective Review. Eur J Cancer 2011. [DOI: 10.1016/s0959-8049(11)71684-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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29
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Stephenson K, Amthor R, Mallowa S, Nungo R, Maziya-Dixon B, Gichuki S, Mbanaso A, Manary M. Consuming cassava as a staple food places children 2-5 years old at risk for inadequate protein intake, an observational study in Kenya and Nigeria. Nutr J 2010; 9:9. [PMID: 20187960 PMCID: PMC2837613 DOI: 10.1186/1475-2891-9-9] [Citation(s) in RCA: 46] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 02/26/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inadequate protein intake is known to be deleterious in animals. Using WHO consensus documents for human nutrient requirements, the protein:energy ratio (P:E) of an adequate diet is > 5%. Cassava has a very low protein content. This study tested the hypothesis that Nigerian and Kenyan children consuming cassava as their staple food are at greater risk for inadequate dietary protein intake than those children who consume less cassava. METHODS A 24 hour dietary recall was used to determine the food and nutrient intake of 656 Nigerian and 449 Kenyan children aged 2-5 years residing in areas where cassava is a staple food. Anthropometric measurements were conducted. Diets were scored for diversity using a 12 point score. Pearson's Correlation Coefficients were calculated to relate the fraction of dietary energy obtained from cassava with protein intake, P:E, and dietary diversity. RESULTS The fraction of dietary energy obtained from cassava was > 25% in 35% of Nigerian children and 89% of Kenyan children. The mean dietary diversity score was 4.0 in Nigerian children and 4.5 in Kenyan children, although the mean number of different foods consumed on the survey day in Nigeria was greater than Kenya, 7.0 compared to 4.6. 13% of Nigerian and 53% of Kenyan children surveyed had inadequate protein intake. The fraction of dietary energy derived from cassava was negatively correlated with protein intake, P:E, and dietary diversity. Height-for age z score was directly associated with protein intake and negatively associated with cassava consumption using regression modeling that controlled for energy and zinc intake. CONCLUSIONS Inadequate protein intake was found in the diets of Nigerian and Kenyan children consuming cassava as a staple food. Inadequate dietary protein intake is associated with stunting in this population. Interventions to increase protein intake in this vulnerable population should be the focus of future work.
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Affiliation(s)
- Kevin Stephenson
- Department of Pediatrics, St Louis Children's Hospital, St Louis, MO, USA
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30
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Ardalan B, Feagans M, Mezentsev D, Jones C, Subbarayan PR, Walker G, Sapp M, Stephenson K, Ness J, Franceschi D, Livingstone A. Phase II study of bevacizumab (B), camptosar (I), high-dose 24-hour continuous intravenous infusion of floxuridine (F) and leucovorin (L) in patients with previously untreated metastatic colon cancer. (B-IFL). J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e15114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e15114 Background: In a previous study, IFL was used in patients (pt) with untreated metastatic colon cancer and a median overall survival (MOS) of 31 months (m). In the current study we added B to IFL to determine toxicity profiles (TP) and the response rate (RR) to the B-IFL regimen. The primary end-point is MOS Methods: Each cycle involved 6 weeks (wks) of treatment. The treatment cycle consisted of a 90 minute infusion of I (110 mg/m2), followed by a 24 hour infusion of F (120mg/kg) and L (500 mg/m2) on wks 1, 2, 4, 5. Pt received B (7.5mg/kg) over 90 minutes on wks 1 and 4 prior to IFL. No therapy was given on wks 3 and 6. Eligible pt received 2 cycles of B-IFL followed by CT scan. Quality of life data and thymidylate synthase expression in peripheral blood mononuclear cells was monitored Results: 22 pt with a median age of 57 (38–82), 11 males and 11 females were enrolled. Median KPS was 90% (50–100). 8 pt (36%) had bilobar liver disease and involvement of 1 other organ, 6 pt (27%) had bilobar liver disease with involvement of ≥ 2 other organs; 5 pt (23.5%) had bilobar liver disease; 2 pt (9%) had abdominal carcinomatosis; 1 pt (4.5 %) had involvement in one liver lobe. Grade (Gr) 4 toxicity: pulmonary embolus 1 pt (5%) incidental CT finding. Gr 3 occurred in 11 pt (50%); DVT, diarrhea (Drh) 3 pt (14%); fatigue (Ftg), infection, port site thrombosis (Pst), small bowel obstruction 2 pt (9%); wound dehiscence 1pt (5%); Gr 2 and 1: constipation; Drh; Ftg; nausea; neutropenia; Pst; alopecia; anorexia; mucositis. 17 pt remain alive with median follow up of 15 m (2–28). 5 pt have died due to progression of disease. The estimated median time to progression was 13 m with corresponding lower 95% confidence bound of 8.4 m. Kaplan-Meier estimate at 2 yr survival is 61% (95% CI 27–83%). RR in 21 pt was 67% (95% CI: 43–85%). Conclusions: B-IFL regimen has a manageable TP. RR and progression free interval were promising. Pt accrual is ongoing. Supported by Pfizer. No significant financial relationships to disclose.
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Affiliation(s)
| | | | | | | | | | | | - M. Sapp
- University of Miami, Miami, FL
| | | | - J. Ness
- University of Miami, Miami, FL
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Stephenson K. Occupational therapy at work in South Australia's SRF sector. Aust Occup Ther J 2008; 55:69-72. [DOI: 10.1111/j.1440-1630.2007.00695.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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32
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Stephenson K. S461 Two-component signal transduction systems of pathogenic bacteria as targets for anti-infective therapy. Int J Antimicrob Agents 2007. [DOI: 10.1016/s0924-8579(07)70307-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kavallaris M, Luduena R, Lu M, Prasaad V, Hammond L, Stephenson K, Arthaud L, Weitman S. 527 ILX651 inhibits polymerization of alpha beta III tubulin and is cytotoxic to beta tubulin mutant tumor cell lines that overexpress beta III tubulin. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80535-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Stephenson K, Hoch JA. Developing inhibitors to selectively target two-component and phosphorelay signal transduction systems of pathogenic microorganisms. Curr Med Chem 2004; 11:765-73. [PMID: 15032730 DOI: 10.2174/0929867043455765] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two-component signal transduction systems and their expanded variants known as phosphorelays are integral elements of the virulence and antimicrobial resistance responses of a wide range of pathogenic bacteria and fungi and also regulate essential functions. As a consequence, two-component systems and phosphorelays are recognized targets for the development of novel antimicrobial agents and a number of chemically synthesized inhibitors from different chemical classes have been identified by compound library screens. However, in the majority of cases these compounds do not appear to be selective for signal transduction pathways and exert their effect by multiple mechanisms of action. The key to designing molecules to selectively disrupt signal transduction may lie with the conserved features of response regulators and the structural analysis of complexes of signaling proteins.
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Affiliation(s)
- K Stephenson
- Department of Microbiology, School of Biochemistry and Biology, University of Leeds, Leeds, UK
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Stephenson K, Hoch JA. Histidine kinase-mediated signal transduction systems of pathogenic microorganisms as targets for therapeutic intervention. Curr Drug Targets Infect Disord 2002; 2:235-46. [PMID: 12462127 DOI: 10.2174/1568005023342443] [Citation(s) in RCA: 23] [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: 11/22/2022]
Abstract
Pathogenic bacteria must be able to sense and respond rapidly to signals emanating from the host environment and use the signals to modulate the expression of genes required for the infection process. Two-component signal transduction systems, and their more complex variants known as phosphorelays, are woven within the fabric of bacterial cellular regulatory processes and are used to regulate the expression of genes involved in the virulence and antibiotic resistance responses of a large number of pathogens of major public health concern. The emergence of strains of pathogenic bacteria that are resistant to multiple antibiotics has driven the search for new targets and/or modes of action for anti-microbial agents. The presence of essential two-component systems in bacteria and the central role that these regulatory systems play in virulence and antibiotic resistance has meant that two-component systems and phosphorelays have been recognized as targets for antimicrobial intervention. This review will discuss the role of these signal transduction pathways in virulence responses and antibiotic sensitivity of pathogenic microorganisms and their potential use as targets for antimicrobial therapy. In addition, the current status on the development of inhibitors specific for two-component systems will be discussed.
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Affiliation(s)
- K Stephenson
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
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Stephenson K, Jensen CL, Jørgensen ST, Harwood CR. Simultaneous inactivation of the wprA and dltB genes of Bacillus subtilis reduces the yield of alpha-amylase. Lett Appl Microbiol 2002; 34:394-7. [PMID: 12028417 DOI: 10.1046/j.1472-765x.2002.01106.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/20/2022]
Abstract
AIMS In Gram-positive bacteria, signal peptide-bearing secretory proteins are translocated through the cytoplasmic membrane and fold into their native conformation on the outside of the cell. The products of the Bacillus subtilis wprA and dltB genes separately influence post-translocational stages of the secretion process by mediating proteolytic degradation and folding of secretory proteins. Inactivation of either wprA or dltB in B. subtilis increases the yield of secretory proteins released into the culture medium in an intact and biologically active conformation. The aim of this work was to study the combined influence of these genes. METHODS AND RESULTS A wprA/dltB double mutant was constructed, but did not have an additive effect on secretion and caused a significant reduction in the yield of alpha-amylase. CONCLUSIONS AND SIGNIFICANCE The activities of the wprA gene and the dlt operon interact in a negative way to influence the growth cycle and protein secretion. The mechanism by which this may occur, and its potential significance for the secretion of native and non-native proteins from B. subtilis and related bacteria, is discussed.
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Affiliation(s)
- K Stephenson
- Department of Microbiology and Immunology, The Medical School, Newcastle upon Tyne, UK
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Stephenson K, Hoch JA. PAS-A domain of phosphorelay sensor kinase A: a catalytic ATP-binding domain involved in the initiation of development in Bacillus subtilis. Proc Natl Acad Sci U S A 2001; 98:15251-6. [PMID: 11734624 PMCID: PMC65015 DOI: 10.1073/pnas.251408398] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [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: 11/18/2022] Open
Abstract
The major sensor kinase controlling the initiation of development in Bacillus subtilis, KinA, functions by activating the phosphorelay signal-transduction system in response to as yet unknown signal ligands. KinA contains, within its amino-terminal signal-sensing region, three PAS domains that, in other proteins, are known to be involved in sensing changes in oxygen concentration and redox potential among other functions. The most amino-terminal PAS domain, PAS-A, was found to bind ATP and catalyze exchange of phosphate between ATP and nucleoside diphosphates. A cysteine-to-alanine mutation in PAS-A increased the affinity for ATP 5-fold, decreased the exchange reaction 2-fold, and stimulated KinA-dependent sporulation. A model for the role of ATP and the exchange reaction in the PAS domain in sensor kinase signal transduction is presented in which the free energy of nucleotide hydrolysis drives the conformational changes that activate or deactivate the sensor kinase in response to signal ligand binding.
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Affiliation(s)
- K Stephenson
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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Wang L, Fabret C, Kanamaru K, Stephenson K, Dartois V, Perego M, Hoch JA. Dissection of the functional and structural domains of phosphorelay histidine kinase A of Bacillus subtilis. J Bacteriol 2001; 183:2795-802. [PMID: 11292798 PMCID: PMC99495 DOI: 10.1128/jb.183.9.2795-2802.2001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The initiation of sporulation in Bacillus subtilis results primarily from phosphoryl group input into the phosphorelay by histidine kinases, the major kinase being kinase A. Kinase A is active as a homodimer, the protomer of which consists of an approximately 400-amino-acid N-terminal putative signal-sensing region and a 200-amino-acid C-terminal autokinase. On the basis of sequence similarity, the N-terminal region may be subdivided into three PAS domains: A, B, and C, located from the N- to the C-terminal end. Proteolysis experiments and two-hybrid analyses indicated that dimerization of the N-terminal region is accomplished through the PAS-B/PAS-C region of the molecule, whereas the most amino-proximal PAS-A domain is not dimerized. N-terminal deletions generated with maltose binding fusion proteins showed that an intact PAS-A domain is very important for enzymatic activity. Amino acid substitution mutations in PAS-A as well as PAS-C affected the in vivo activity of kinase A, suggesting that both PAS domains are required for signal sensing. The C-terminal autokinase, when produced without the N-terminal region, was a dimer, probably because of the dimerization required for formation of the four-helix-bundle phosphotransferase domain. The truncated autokinase was virtually inactive in autophosphorylation with ATP, whereas phosphorylation of the histidine of the phosphotransfer domain by back reactions from Spo0F~P appeared normal. The phosphorylated autokinase lost the ability to transfer its phosphoryl group to ADP, however. The N-terminal region appears to be essential both for signal sensing and for maintaining the correct conformation of the autokinase component domains.
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Affiliation(s)
- L Wang
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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Abstract
Two-component signal transduction systems allow bacteria to sense and respond rapidly to changes in their environment leading to specific gene activation or repression. These two-component systems are integral in the ability of pathogenic bacteria to mount and establish a successful infection within the host and, consequently, have been recognized as targets for new anti-microbial agents. In this paper, we define the site and mechanism of action of several previously identified inhibitors of bacterial two-component systems. We show that the most potent inhibitors target the carboxyl-terminal catalytic domain of the sensor kinase and exert their affect by causing structural alterations of the kinase leading to aggregation. Recognition of this phenomenon has important implications for the development of novel inhibitors of two-component systems and should facilitate the rapid identification and elimination of compounds with nonspecific affects from medicinal chemistry drug discovery programs.
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Affiliation(s)
- K Stephenson
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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Kastrati A, Koch W, Berger PB, Mehilli J, Stephenson K, Neumann FJ, von Beckerath N, Böttiger C, Duff GW, Schömig A. Protective role against restenosis from an interleukin-1 receptor antagonist gene polymorphism in patients treated with coronary stenting. J Am Coll Cardiol 2000; 36:2168-73. [PMID: 11127457 DOI: 10.1016/s0735-1097(00)01014-7] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To test the hypothesis that interleukin-1 receptor antagonist (IL-1ra) gene polymorphism contributes to the risk of restenosis after coronary stenting. BACKGROUND Cytokines of the interleukin-1 (IL-1) family play a central role in regulating inflammatory responses. There is strong evidence to support IL-1 involvement in smooth muscle cell mitogenesis and extracellular matrix metabolism. The IL-1ra counters the proinflammatory effects of IL-1. The interleukin-1 receptor antagonist gene (IL-1RN) contains several well-characterized polymorphic sites that correlate with altered IL-lra levels. METHODS In 1,850 consecutive patients, clinical and angiographic measures ofrestenosis were evaluated over one year after coronary stent placement. Repeat angiography at six months was achieved in 84% of the patients; angiographic restenosis was defined < or =50% diameter stenosis at follow-up. Genotyping for an exon 2 polymorphism (+2,018) of IL-1RN (alleles 1 and 2) was based on a polymerase chain reaction technique. RESULTS Allele 2 frequency was 0.28. Carriers of allele 2 had a significantly lower risk for angiographic restenosis, odds ratio (OR) of 0.78 (95% confidence interval, 0.63 to 0.97) and target vessel revascularization, OR of 0.73 (0.58 to 0.92) compared with noncarriers. Risk reduction was especially significant in patients <60 years (n = 696), with OR of 0.63 (0.43 to 0.91) for angiographic restenosis and 0.55 (0.39 to 0.78) for target vessel revascularization. CONCLUSIONS Allele 2 of the IL-1ra gene was associated with a lower incidence of restenosis after coronary stenting, particularly in younger patients. This finding supports a role of inflammation in the development of restenosis after stent placement.
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Affiliation(s)
- A Kastrati
- Deutsches Herzzentrum München and 1. Medizinische Klinik rechts der Isar, Technische Universität München, Munich, Germany.
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Hyyrylainen HL, Vitikainen M, Thwaite J, Wu H, Sarvas M, Harwood CR, Kontinen VP, Stephenson K. D-Alanine substitution of teichoic acids as a modulator of protein folding and stability at the cytoplasmic membrane/cell wall interface of Bacillus subtilis. J Biol Chem 2000; 275:26696-703. [PMID: 10871614 DOI: 10.1074/jbc.m003804200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [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: 11/06/2022] Open
Abstract
The extracytoplasmic folding of secreted proteins in Gram-positive bacteria is influenced by the microenvironment of the compartment into which they are translocated, namely the negatively charged matrix of the cell wall polymers. In this compartment, the PrsA lipoprotein facilitates correct post-translocational folding or prevents misfolding of secreted proteins. In this study, a secretion mutant of B. subtilis (prsA3) encoding a defective PrsA protein was mutagenized and screened for restored secretion of the AmyQ alpha-amylase. One mini-Tn10 insertion, which partially suppressed the secretion deficiency, was found to interrupt dlt, the operon involved in the d-alanylation of teichoic acids. The inactivation of dlt rescued the mutant PrsA3 protein from degradation, and the increased amount of PrsA3 was shown to enhance the secretion of PrsA-dependent proteins. Heterologous or abnormal secreted proteins, which are prone to degradation after translocation, were also stabilized and secreted in increased quantities from a dlt prsA(+) strain. Furthermore, the dlt mutation partially suppressed the lethal effect of PrsA depletion, suggesting that the dlt deficiency also leads to stabilization of an essential cell wall protein(s). Our results suggest that main influence of the increased net negative charge of the wall caused by the absence of d-alanine is to increase the rate of post-translocational folding of exported proteins.
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Affiliation(s)
- H L Hyyrylainen
- Vaccine Development Laboratory, National Public Health Institute, FI-00300 Helsinki, Finland
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Stephenson K, Jensen CL, Jørgensen ST, Lakey JH, Harwood CR. The influence of secretory-protein charge on late stages of secretion from the Gram-positive bacterium Bacillus subtilis. Biochem J 2000; 350 Pt 1:31-9. [PMID: 10926823 PMCID: PMC1221221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Following their secretion across the cytoplasmic membrane, processed secretory proteins of Bacillus subtilis must fold into their native conformation prior to translocation through the cell wall and release into the culture medium. The rate and efficiency of folding are critical in determining the yields of intact secretory proteins. The B. subtilis membrane is surrounded by a thick cell wall comprising a heteropolymeric matrix of peptidoglycan and anionic polymers. The latter confer a high density of negative charge on the wall, endowing it with ion-exchange properties, and secretory proteins destined for the culture medium must traverse the wall as the last stage in the export process. To determine the influence of charge on late stages in the secretion of proteins from this bacterium, we have used sequence data from two related alpha-amylases, to engineer the net charge of AmyL, an alpha-amylase from Bacillus licheniformis that is normally secreted efficiently from B. subtilis. While AmyL has a pI of 7.0, chimaeric enzymes with pI values of 5.0 and 10.0 were produced and characterized. Despite the engineered changes to their physico-chemical properties, the chimaeric enzymes retained many of the enzymic characteristics of AmyL. We show that the positively charged protein interacts with the cell wall in a manner that influences its secretion.
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Affiliation(s)
- K Stephenson
- Department of Microbiology and Immunology, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne, NE24HH, U.K
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Bolhuis A, Tjalsma H, Stephenson K, Harwood CR, Venema G, Bron S, van Dijl JM. Different mechanisms for thermal inactivation of Bacillus subtilis signal peptidase mutants. J Biol Chem 1999; 274:15865-8. [PMID: 10336490 DOI: 10.1074/jbc.274.22.15865] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The type I signal peptidase SipS of Bacillus subtilis is of major importance for the processing of secretory precursor proteins. In the present studies, we have investigated possible mechanisms of thermal inactivation of five temperature-sensitive SipS mutants. The results demonstrate that two of these mutants, L74A and Y81A, are structurally stable but strongly impaired in catalytic activity at 48 degrees C, showing the (unprecedented) involvement of the conserved leucine 74 and tyrosine 81 residues in the catalytic reaction of type I signal peptidases. This conclusion is supported by the crystal structure of the homologous signal peptidase of Escherichia coli (Paetzel, M., Dalbey, R. E., and Strynadka, N. C. J. (1998) Nature 396, 186-190). In contrast, the SipS mutant proteins R84A, R84H, and D146A were inactivated by proteolytic degradation, indicating that the conserved arginine 84 and aspartic acid 146 residues are required to obtain a protease-resistant conformation. The cell wall-bound protease WprA was shown to be involved in the degradation of SipS D146A, which is in accord with the fact that SipS has a large extracytoplasmic domain. As WprA was not involved in the degradation of the SipS mutant proteins R84A and R84H, we conclude that multiple proteases are responsible for the thermal inactivation of temperature-sensitive SipS mutants.
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Affiliation(s)
- A Bolhuis
- Department of Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Kerklaan 30, 9751 NN Haren, The Netherlands
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Stephenson K. Open clinical trials for HIV/AIDS treatments. BETA 1998:56-8. [PMID: 11365994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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Abstract
AmyL, an extracellular alpha-amylase from Bacillus licheniformis, is resistant to extracellular proteases secreted by Bacillus subtilis during growth. Nevertheless, when AmyL is produced and secreted by B. subtilis, it is subject to considerable cell-associated proteolysis. Cell-wall-bound proteins CWBP52 and CWBP23 are the processed products of the B. subtilis wprA gene. Although no activity has been ascribed to CWBP23, CWBP52 exhibits serine protease activity. Using a strain encoding an inducible wprA gene, we show that a product of wprA, most likely CWBP52, is involved in the posttranslocational stability of AmyL. A construct in which wprA is not expressed exhibits an increased yield of alpha-amylase. The potential role of wprA in protein secretion is discussed, together with implications for the use of B. subtilis and related bacteria as hosts for the secretion of heterologous proteins.
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Affiliation(s)
- K Stephenson
- School of Microbiological, Immunological, and Virological Sciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, NE2 4HH, United Kingdom
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Stephenson K, Carter NM, Harwood CR, Petit-Glatron MF, Chambert R. The influence of protein folding on late stages of the secretion of alpha-amylases from Bacillus subtilis. FEBS Lett 1998; 430:385-9. [PMID: 9688576 DOI: 10.1016/s0014-5793(98)00698-x] [Citation(s) in RCA: 35] [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] [Indexed: 11/18/2022]
Abstract
A derivative of the alpha-amylase from Bacillus licheniformis (AmyL) engineered to give an active enzyme with increased net positive charge is secreted by Bacillus subtilis with a yield that is significantly lower than that of the native enzyme. This reduction in yield is the result of increased proteolysis during or shortly after translocation through the cytoplasmic membrane. When we compared the overall rate of folding of the engineered derivative (AmyLQS50.5) with that of AmyL it exhibited a greater dependency on Ca2+ ions for in vitro folding. When the concentration of Ca2+ in the growth medium was increased, so too did the relative yield of AmyLQS50.5. We discuss the importance of secretory protein folding at the membrane/cell wall interface with respect to the yield of native and heterologous proteins from B. subtilis.
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Affiliation(s)
- K Stephenson
- School of Microbiological, Immunological and Virological Sciences, The Medical School, University of Newcastle upon Tyne, UK
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Stephenson K. Open clinical trials for HIV/AIDS treatments. BETA 1998:43-5, 54. [PMID: 11365564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Affiliation(s)
- K Stephenson
- San Francisco General Hospital, AIDS Program, San Francisco, CA
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Stephenson K. Open clinical trials for HIV/AIDS treatments. BETA 1998:57-9. [PMID: 11365270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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Gupta M, Stephenson K, Gauar S, Frenkel L. Intravenous pentamidine as an alternate for Pneumocystis carinii pneumonia prophylaxis in children with HIV infection. Pediatr Pulmonol Suppl 1998; 16:199-200. [PMID: 9443273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- M Gupta
- Division of Pediatric Immunology, Allergy and Infectious Diseases, UMDNJ-Robert Wood Johnson Medical School, New Brunswick, USA
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