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Voigt C, Virkkala AM, Hould Gosselin G, Bennett KA, Black TA, Detto M, Chevrier-Dion C, Guggenberger G, Hashmi W, Kohl L, Kou D, Marquis C, Marsh P, Marushchak ME, Nesic Z, Nykänen H, Saarela T, Sauheitl L, Walker B, Weiss N, Wilcox EJ, Sonnentag O. Arctic soil methane sink increases with drier conditions and higher ecosystem respiration. Nat Clim Chang 2023; 13:1095-1104. [PMID: 37810622 PMCID: PMC10550823 DOI: 10.1038/s41558-023-01785-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 07/31/2023] [Indexed: 10/10/2023]
Abstract
Arctic wetlands are known methane (CH4) emitters but recent studies suggest that the Arctic CH4 sink strength may be underestimated. Here we explore the capacity of well-drained Arctic soils to consume atmospheric CH4 using >40,000 hourly flux observations and spatially distributed flux measurements from 4 sites and 14 surface types. While consumption of atmospheric CH4 occurred at all sites at rates of 0.092 ± 0.011 mgCH4 m-2 h-1 (mean ± s.e.), CH4 uptake displayed distinct diel and seasonal patterns reflecting ecosystem respiration. Combining in situ flux data with laboratory investigations and a machine learning approach, we find biotic drivers to be highly important. Soil moisture outweighed temperature as an abiotic control and higher CH4 uptake was linked to increased availability of labile carbon. Our findings imply that soil drying and enhanced nutrient supply will promote CH4 uptake by Arctic soils, providing a negative feedback to global climate change.
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Affiliation(s)
- Carolina Voigt
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
- Département de géographie & Centre d’études nordiques, Université de Montréal, Montréal, Quebec Canada
- Institute of Soil Science, Universität Hamburg, Hamburg, Germany
| | | | - Gabriel Hould Gosselin
- Département de géographie & Centre d’études nordiques, Université de Montréal, Montréal, Quebec Canada
- Department of Geography and Environmental Studies & Cold Regions Research Centre, Wilfrid Laurier University, Waterloo, Ontario Canada
| | - Kathryn A. Bennett
- Département de géographie & Centre d’études nordiques, Université de Montréal, Montréal, Quebec Canada
| | - T. Andrew Black
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia Canada
| | - Matteo Detto
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ USA
| | - Charles Chevrier-Dion
- Département de géographie & Centre d’études nordiques, Université de Montréal, Montréal, Quebec Canada
| | - Georg Guggenberger
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany
| | - Wasi Hashmi
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Lukas Kohl
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Dan Kou
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Charlotte Marquis
- Département de géographie & Centre d’études nordiques, Université de Montréal, Montréal, Quebec Canada
| | - Philip Marsh
- Department of Geography and Environmental Studies & Cold Regions Research Centre, Wilfrid Laurier University, Waterloo, Ontario Canada
| | - Maija E. Marushchak
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Zoran Nesic
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia Canada
| | - Hannu Nykänen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Taija Saarela
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Leopold Sauheitl
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany
| | - Branden Walker
- Department of Geography and Environmental Studies & Cold Regions Research Centre, Wilfrid Laurier University, Waterloo, Ontario Canada
| | - Niels Weiss
- Department of Geography and Environmental Studies & Cold Regions Research Centre, Wilfrid Laurier University, Waterloo, Ontario Canada
- Northwest Territories Geological Survey, Yellowknife, Northwest Territories Canada
| | - Evan J. Wilcox
- Department of Geography and Environmental Studies & Cold Regions Research Centre, Wilfrid Laurier University, Waterloo, Ontario Canada
| | - Oliver Sonnentag
- Département de géographie & Centre d’études nordiques, Université de Montréal, Montréal, Quebec Canada
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Survilienė V, Rukšėnas O, Pomeroy PP, Moss SEW, Bennett KA. Evaluating suitability of saliva to measure steroid concentrations in grey seal pups. Gen Comp Endocrinol 2022; 326:114070. [PMID: 35671833 DOI: 10.1016/j.ygcen.2022.114070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 10/21/2021] [Revised: 05/04/2022] [Accepted: 06/02/2022] [Indexed: 11/28/2022]
Abstract
Measurement of steroids in wild pinnipeds can facilitate assessment of breeding, nutritional and stress status, and is useful in understanding behavioral responses. Even in young animals, sex steroids may be important in behavioral interactions and immune modulation. Use of saliva can avoid the large fluctuations seen in some steroids in plasma, and can negate the need for venipuncture, making it a potentially useful matrix in the wildlife. However, its utility in estimating steroid levels in wild young pinnipeds has not been evaluated. Here, we investigated the suitability of saliva for steroid hormone analysis in wild grey seal pups during their suckling and post-weaning fast periods. We collected saliva (n = 38) and plasma (n = 71) samples during the breeding season on the Isle of May, Scotland, 2012. We investigated success of sample collection, ease of preparation, accuracy and precision of analysis, and, where possible, comparability of measurements (n = 27) from saliva and plasma. Plasma sampling was rapid, whereas sampling saliva took up to five times longer. Analytical performance criteria (parallelism, accuracy, and precision (intra and inter assay co-efficient of variation (% CV)) of commercial ELISA kits to measure estradiol, testosterone and cortisol in both matrices were assessed. Estradiol and cortisol assays performed well and can be used in plasma and saliva. However, we could not confidently validate testosterone for either matrix. Saliva estradiol correlated with levels in plasma. Saliva sample preparation was faster and simpler than plasma preparation because it did not require extraction. However, given the additional time taken to obtain saliva in the wild, the possibility of blood contamination from oral damage and the lower success rate in obtaining sufficient sample for analysis, we recommend that this matrix only be used as an alternative to plasma sampling measurement in pinnipeds when animals are anaesthetized, tolerate mouth swabbing, or have been trained to accept saliva sampling in captivity.
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Affiliation(s)
- V Survilienė
- Institute of Biosciences, Life Sciences Centre, Vilnius University, Saulėtekio av. 7, LT-10257, Lithuania.
| | - O Rukšėnas
- Institute of Biosciences, Life Sciences Centre, Vilnius University, Saulėtekio av. 7, LT-10257, Lithuania
| | - P P Pomeroy
- Sea Mammal Research Unit (SMRU), Scottish Ocean Institute, East Sands, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | - S E W Moss
- Sea Mammal Research Unit (SMRU), Scottish Ocean Institute, East Sands, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | - K A Bennett
- School of Applied Sciences, Division of Health Sciences, Abertay University, Bell Street, Dundee DD1 1HG, UK
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Bristow TF, Grotzinger JP, Rampe EB, Cuadros J, Chipera SJ, Downs GW, Fedo CM, Frydenvang J, McAdam AC, Morris RV, Achilles CN, Blake DF, Castle N, Craig P, Des Marais DJ, Downs RT, Hazen RM, Ming DW, Morrison SM, Thorpe MT, Treiman AH, Tu V, Vaniman DT, Yen AS, Gellert R, Mahaffy PR, Wiens RC, Bryk AB, Bennett KA, Fox VK, Millken RE, Fraeman AA, Vasavada AR. Brine-driven destruction of clay minerals in Gale crater, Mars. Science 2021; 373:198-204. [PMID: 34244410 DOI: 10.1126/science.abg5449] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 05/28/2021] [Indexed: 11/02/2022]
Abstract
Mars' sedimentary rock record preserves information on geological (and potential astrobiological) processes that occurred on the planet billions of years ago. The Curiosity rover is exploring the lower reaches of Mount Sharp, in Gale crater on Mars. A traverse from Vera Rubin ridge to Glen Torridon has allowed Curiosity to examine a lateral transect of rock strata laid down in a martian lake ~3.5 billion years ago. We report spatial differences in the mineralogy of time-equivalent sedimentary rocks <400 meters apart. These differences indicate localized infiltration of silica-poor brines, generated during deposition of overlying magnesium sulfate-bearing strata. We propose that destabilization of silicate minerals driven by silica-poor brines (rarely observed on Earth) was widespread on ancient Mars, because sulfate deposits are globally distributed.
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Affiliation(s)
- T F Bristow
- Eobiology Branch, NASA Ames Research Center, Moffett Field, CA 94035, USA.
| | - J P Grotzinger
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - E B Rampe
- Astromaterials Research and Exploration Science Division, NASA Johnson Space Center, Houston, TX 77058, USA
| | - J Cuadros
- Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK
| | - S J Chipera
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - G W Downs
- Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA
| | - C M Fedo
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, USA
| | - J Frydenvang
- Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - A C McAdam
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - R V Morris
- Astromaterials Research and Exploration Science Division, NASA Johnson Space Center, Houston, TX 77058, USA
| | - C N Achilles
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D F Blake
- Eobiology Branch, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - N Castle
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - P Craig
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - D J Des Marais
- Eobiology Branch, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - R T Downs
- Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA
| | - R M Hazen
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - D W Ming
- Astromaterials Research and Exploration Science Division, NASA Johnson Space Center, Houston, TX 77058, USA
| | - S M Morrison
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - M T Thorpe
- Jacobs Technology-Jacobs JETS Contract, Astromaterials Research and Exploration Science Division, at NASA Johnson Space Center, Houston, TX 77058, USA
| | - A H Treiman
- Lunar and Planetary Institute, Universities Space Research Association, Houston, TX 77058, USA
| | - V Tu
- Jacobs Technology-Jacobs JETS Contract, Astromaterials Research and Exploration Science Division, at NASA Johnson Space Center, Houston, TX 77058, USA
| | - D T Vaniman
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - A S Yen
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - R Gellert
- Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - P R Mahaffy
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - R C Wiens
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - A B Bryk
- Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720, USA
| | - K A Bennett
- U.S. Geological Survey, Astrogeology Science Center, Flagstaff, AZ 86001, USA
| | - V K Fox
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - R E Millken
- Department of Earth, Environmental Sciences and Planetary Sciences, Brown University, Providence, RI 02912, USA
| | - A A Fraeman
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - A R Vasavada
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
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Perryman CR, Wirsing J, Bennett KA, Brennick O, Perry AL, Williamson N, Ernakovich JG. Heavy metals in the Arctic: Distribution and enrichment of five metals in Alaskan soils. PLoS One 2020; 15:e0233297. [PMID: 32492035 PMCID: PMC7269202 DOI: 10.1371/journal.pone.0233297] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 05/02/2020] [Indexed: 11/18/2022] Open
Abstract
Metal contamination of food and water resources is a known public health issue in Arctic and sub-Arctic communities due to the proximity of many communities to mining and drilling sites. In addition, permafrost thaw may release heavy metals sequestered in previously frozen soils, potentially contaminating food and water resources by increasing the concentration of metals in freshwater, plants, and wildlife. Here we assess the enrichment of selected heavy metals in Alaskan soils by synthesizing publicly available data of soil metal concentrations. We analyzed data of soil concentrations of arsenic, chromium, mercury, nickel, and lead from over 1,000 samples available through the USGS Alaskan Geochemical Database to evaluate 1) the spatial distribution of sampling locations for soil metal analysis, 2) metal concentrations in soils from different land cover types and depths, and 3) the occurrence of soils in Alaska with elevated metal concentrations relative to other soils. We found substantial clustering of sample sites in the southwestern portion of Alaska in discontinuous and sporadic permafrost, while the continuous permafrost zone in Northern Alaska and the more populous Interior are severely understudied. Metal concentration varied by land cover type but lacked consistent patterns. Concentrations of chromium, mercury, and lead were higher in soils below 10 cm depth, however these deeper soils are under-sampled. Arsenic, chromium, mercury, nickel and lead concentrations exceeded average values for US soils by one standard deviation or more in 3.7% to 18.7% of the samples in this dataset. Our analysis highlights critical gaps that impede understanding of how heavy metals in thawing permafrost soils may become mobilized and increase exposure risk for Arctic communities.
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Affiliation(s)
- Clarice R. Perryman
- Department of Earth Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, United States of America
- * E-mail:
| | - Jochen Wirsing
- Sociology Department, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Kathryn A. Bennett
- Department of Earth Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Owen Brennick
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Apryl L. Perry
- Department of Earth Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Nicole Williamson
- Environmental Science and Studies Program, Towson University, Towson, Maryland, United States of America
- Department of Biological Sciences, Towson University, Towson, Maryland, United States of America
| | - Jessica G. Ernakovich
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, United States of America
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Chen F, Shapiro GI, Bennett KA, Ingram SN, Thompson D, Vincent C, Russell DJF, Embling CB. Shipping noise in a dynamic sea: a case study of grey seals in the Celtic Sea. Mar Pollut Bull 2017; 114:372-383. [PMID: 27677390 DOI: 10.1016/j.marpolbul.2016.09.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/21/2016] [Accepted: 09/22/2016] [Indexed: 06/06/2023]
Abstract
Shipping noise is a threat to marine wildlife. Grey seals are benthic foragers, and thus experience acoustic noise throughout the water column, which makes them a good model species for a case study of the potential impacts of shipping noise. We used ship track data from the Celtic Sea, seal track data and a coupled ocean-acoustic modelling system to assess the noise exposure of grey seals along their tracks. It was found that the animals experience step changes in sound levels up to ~20dB at a frequency of 125Hz, and ~10dB on average over 10-1000Hz when they dive through the thermocline, particularly during summer. Our results showed large seasonal differences in the noise level experienced by the seals. These results reveal the actual noise exposure by the animals and could help in marine spatial planning.
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Affiliation(s)
- F Chen
- School of Marine Science and Engineering, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
| | - G I Shapiro
- School of Marine Science and Engineering, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK
| | - K A Bennett
- School of Marine Science and Engineering, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK; School of Science, Engineering and Technology, Abertay University, Dundee, UK
| | - S N Ingram
- School of Marine Science and Engineering, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK
| | - D Thompson
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, UK
| | - C Vincent
- Centre d'Etudes Biologiques de Chizé, CNRS/University of La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - D J F Russell
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, UK
| | - C B Embling
- School of Marine Science and Engineering, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK
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Bennett KA, Hughes J, Stamatas S, Brand S, Foster NL, Moss SEW, Pomeroy PP. Adiponectin and Insulin in Gray Seals during Suckling and Fasting: Relationship with Nutritional State and Body Mass during Nursing in Mothers and Pups. Physiol Biochem Zool 2015; 88:295-310. [PMID: 25860828 DOI: 10.1086/680862] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Animals that fast during breeding and/or development, such as phocids, must regulate energy balance carefully to maximize reproductive fitness and survival probability. Adiponectin, produced by adipose tissue, contributes to metabolic regulation by modulating sensitivity to insulin, increasing fatty acid oxidation by liver and muscle, and promoting adipogenesis and lipid storage in fat tissue. We tested the hypotheses that (1) circulating adiponectin, insulin, or relative adiponectin gene expression is related to nutritional state, body mass, and mass gain in wild gray seal pups; (2) plasma adiponectin or insulin is related to maternal lactation duration, body mass, percentage milk fat, or free fatty acid (FFA) concentration; and (3) plasma adiponectin and insulin are correlated with circulating FFA in females and pups. In pups, plasma adiponectin decreased during suckling (linear mixed-effects model [LME]: T = 4.49; P < 0.001) and the early postweaning fast (LME: T = 3.39; P = 0.004). In contrast, their blubber adiponectin gene expression was higher during the early postweaning fast than early in suckling (LME: T = 2.11; P = 0.046). Insulin levels were significantly higher in early (LME: T = 3.52; P = 0.004) and late (LME: T = 6.99; P < 0.001) suckling than in fasting and, given the effect of nutritional state, were also positively related to body mass (LME: T = 3.58; P = 0.004). Adiponectin and insulin levels did not change during lactation and were unrelated to milk FFA or percentage milk fat in adult females. Our data suggest that adiponectin, in conjunction with insulin, may facilitate fat storage in seals and is likely to be particularly important in the development of blubber reserves in pups.
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Affiliation(s)
- K A Bennett
- Marine Biology and Ecology Research Centre, School of Marine Science and Engineering, Plymouth University, Portland Square, Drake Circus, Plymouth, Devon PL4 8AA, United Kingdom; 2Natural Environment Research Council Sea Mammal Research Unit, Gatty Marine Laboratories, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY16 8LB, United Kingdom
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Bennett KA, Hammill M, Currie S. Liver glucose-6-phosphatase proteins in suckling and weaned grey seal pups: structural similarities to other mammals and relationship to nutrition, insulin signalling and metabolite levels. J Comp Physiol B 2013; 183:1075-88. [PMID: 23743798 DOI: 10.1007/s00360-013-0768-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Revised: 05/10/2013] [Accepted: 05/21/2013] [Indexed: 01/05/2023]
Abstract
Phocid seals have been proposed as models for diabetes because they exhibit limited insulin response to glucose, high blood glucose and increasing insulin resistance when fasting. Liver glucose-6-phosphatase (G6Pase) catalyses the final step in glucose production and is central to glucose regulation in other animals. G6Pase comprises a translocase (SLC37A4) and a catalytic subunit (G6PC). G6PC and SLC37A4 expression and activity are normally regulated by nutritional state and glucostatic hormones, particularly insulin, and are elevated in diabetes. We tested the hypotheses that (1) grey seal G6PC and SLC37A4 cDNA and predicted protein sequences differ from other species' at functional sites, (2) relative G6Pase protein abundances are lower during feeding than fasting and (3) relative G6Pase protein abundances are related to insulin, insulin receptor phosphorylation and key metabolite levels. We show that G6PC and partial SLC37A4 cDNA sequences encode proteins sharing 82-95 % identity with other mammals. Seal G6PC contained no differences in sites responsible for activity, stability or subcellular location. Several substitutions in seal SLC37A4 were predicted to be tolerated with low probability, which could affect glucose production. Suckling pups had higher relative abundance of both subunits than healthy, postweaned fasting pups. Furthermore, relative G6PC abundance was negatively related to glucose levels. These findings contrast markedly with the response of relative hepatic G6Pase abundance to feeding, fasting, insulin, insulin sensitivity and key metabolites in other animals, and highlight the need to understand the regulation of enzymes involved in glucose control in phocids if these animals are to be informative models of diabetes.
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Affiliation(s)
- K A Bennett
- Marine Biology and Ecology Research Centre, School of Marine Science and Engineering, Plymouth University, Portland Square, Drake Circus, Plymouth, Devon, PL4 8AA, UK,
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Nowak EC, de Vries VC, Wasiuk A, Ahonen C, Bennett KA, Le Mercier I, Ha DG, Noelle RJ. Tryptophan hydroxylase-1 regulates immune tolerance and inflammation. ACTA ACUST UNITED AC 2012; 209:2127-35. [PMID: 23008335 PMCID: PMC3478935 DOI: 10.1084/jem.20120408] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Tryptophan hydroxylase deficiency in mast cells breaks allograft tolerance, induces tumor remission, and intensifies neuroinflammation. Nutrient deprivation based on the loss of essential amino acids by catabolic enzymes in the microenvironment is a critical means to control inflammatory responses and immune tolerance. Here we report the novel finding that Tph-1 (tryptophan hydroxylase-1), a synthase which catalyses the conversion of tryptophan to serotonin and exhausts tryptophan, is a potent regulator of immunity. In models of skin allograft tolerance, tumor growth, and experimental autoimmune encephalomyelitis, Tph-1 deficiency breaks allograft tolerance, induces tumor remission, and intensifies neuroinflammation, respectively. All of these effects of Tph-1 deficiency are independent of its downstream product serotonin. Because mast cells (MCs) appear to be the major source of Tph-1 and restoration of Tph-1 in the MC compartment in vivo compensates for the defect, these experiments introduce a fundamentally new mechanism of MC-mediated immune suppression that broadly impacts multiple arms of immunity.
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Affiliation(s)
- Elizabeth C Nowak
- Department of Microbiology and Immunology, Dartmouth Medical School and the Norris Cotton Cancer Center, Lebanon, NH 03756, USA
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Pino-Lagos K, Guo Y, Brown C, Alexander MP, Elgueta R, Bennett KA, De Vries V, Nowak E, Blomhoff R, Sockanathan S, Chandraratna RA, Dmitrovsky E, Noelle RJ. A retinoic acid-dependent checkpoint in the development of CD4+ T cell-mediated immunity. ACTA ACUST UNITED AC 2011; 208:1767-75. [PMID: 21859847 PMCID: PMC3171100 DOI: 10.1084/jem.20102358] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Immune cell activation induces concurrent temporal and spatial retinoic acid signaling, and CD4+ T cell–specific loss of RA signals reduces effector function, migration, and polarity. It is known that vitamin A and its metabolite, retinoic acid (RA), are essential for host defense. However, the mechanisms for how RA controls inflammation are incompletely understood. The findings presented in this study show that RA signaling occurs concurrent with the development of inflammation. In models of vaccination and allogeneic graft rejection, whole body imaging reveals that RA signaling is temporally and spatially restricted to the site of inflammation. Conditional ablation of RA signaling in T cells significantly interferes with CD4+ T cell effector function, migration, and polarity. These findings provide a new perspective of the role of RA as a mediator directly controlling CD4+ T cell differentiation and immunity.
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Affiliation(s)
- Karina Pino-Lagos
- Department of Microbiology and Immunology, Dartmouth Medical School, Norris Cotton Cancer Center, Lebanon, NH 03756, USA
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Crane JMG, Delaney T, Butt KD, Bennett KA, Hutchens D, Young DC. Predictors of successful labor induction with oral or vaginal misoprostol. J Matern Fetal Neonatal Med 2010; 15:319-23. [PMID: 15280123 DOI: 10.1080/14767050410001702195] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [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: 10/26/2022]
Abstract
OBJECTIVE To identify independent predictors of successful labor induction with oral or vaginal misoprostol. METHODS Women enrolled in four previous randomized trials involving oral or vaginal misoprostol for cervical ripening and labor induction were included in the present cohort study, with dosing of 25-50 microg every 4 to 6 h vaginally (n = 574) or 50 microg every 4 h orally (n = 207). Multiple logistic regression was performed to identify factors independently associated with successful labor induction -- defined as vaginal delivery within 12 h, vaginal delivery within 24 h and spontaneous vaginal delivery. Predictors of Cesarean birth and the need for only one dose of misoprostol were also identified. Variables included in the models were maternal age, weight, height, parity, gravidity, membrane status, route of misoprostol, gestational age, birth weight, and Bishop score and its individual components. RESULTS Maternal age, height, weight, parity, birth weight, dilatation, effacement and cervical station were associated with vaginal delivery within 24 h of induction. Maternal age, height, weight, nulliparity, birth weight and route of misoprostol were associated with Cesarean birth, with oral misoprostol being associated with a lower rate of Cesarean birth. The need for only one dose of misoprostol was predicted by maternal height, weight, parity, gestational age, Bishop score and route of misoprostol. CONCLUSION Characteristics of the woman (height, weight, parity), the fetus (birth weight) and some of the individual components of the Bishop score, were associated with successful labor induction, with oral misoprostol being associated with a lower rate of Cesarean birth.
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Affiliation(s)
- J M G Crane
- Department of Obstetrics and Gynecology, Memorial University of Newfoundland, St John's, Newfoundland, Canada
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Abstract
Mast cells (MC) have been shown to mediate regulatory T-cell (T(reg))-dependent, peripheral allograft tolerance in both skin and cardiac transplants. Furthermore, T(reg) have been implicated in mitigating IgE-mediated MC degranulation, establishing a dynamic, reciprocal relationship between MC and T(reg) in controlling inflammation. In an allograft tolerance model, it is now shown that intragraft or systemic MC degranulation results in the transient loss of T(reg) suppressor activities with the acute, T-cell dependent rejection of established, tolerant allografts. Upon degranulation, MC mediators can be found in the skin, T(reg) rapidly leave the graft, MC accumulate in the regional lymph node and the T(reg) are impaired in the expression of suppressor molecules. Such a dramatic reversal of T(reg) function and tissue distribution by MC degranulation underscores how allergy may causes the transient breakdown of peripheral tolerance and episodes of acute T-cell inflammation.
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Affiliation(s)
- Victor C. de Vries
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756
| | - Anna Wasiuk
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756
| | - Kathryn A. Bennett
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756
| | - Micah J. Benson
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756
| | - Raul Elgueta
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756
| | | | - Randolph. J. Noelle
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756
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Gondek DC, Devries V, Nowak EC, Lu LF, Bennett KA, Scott ZA, Noelle RJ. Transplantation survival is maintained by granzyme B+ regulatory cells and adaptive regulatory T cells. J Immunol 2008; 181:4752-60. [PMID: 18802078 DOI: 10.4049/jimmunol.181.7.4752] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Granzyme B (GZB) has been implicated as an effector mechanism in regulatory T cells (T(reg)) suppression. In a model of T(reg)-dependent graft tolerance, it is shown that GZB- deficient mice are unable to establish long-term tolerance. Moreover, mice overexpressing the inhibitor of GZB, serine protease inhibitor 6, are also resistant to tolerization to alloantigen. Graft survival was shorter in bone marrow-mixed chimeras reconstituted with GZB-deficient T(reg) as compared with wild-type T(reg). Whereas there was no difference in graft survival in mixed chimeras reconstituted with wild-type, perforin-deficient, or Fas ligand-deficient T(reg). Finally, data also show that if alloreactive effectors cannot express FoxP3 and be induced to convert in the presence of competent T(reg), then graft tolerance is lost. Our data are the first in vivo data to implicate GZB expression by T(reg) in sustaining long-lived graft survival.
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Affiliation(s)
- David C Gondek
- Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756, USA
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Abstract
OBJECTIVE To estimate the incidence and timing of excessive uterine activity accompanying induction of labor with misoprostol using different routes (oral or vaginal) and forms (intact tablet or crushed) and to compare these with dinoprostone gel, oxytocin, and spontaneous labor. METHODS This retrospective cohort study included 519 women at term who had labor induced and 86 women at term in spontaneous labor. Induction agents included misoprostol, dinoprostone, or oxytocin. Fetal heart rate and uterine activity tracings were analyzed independently by three maternal-fetal medicine physicians. The diagnosis of tachysystole or hyperstimulation required the agreement of two or more reviewers. RESULTS The incidence of tachysystole was highest with misoprostol administered by vaginal tablet (misoprostol vaginal tablet 50 microg every 4 hours, 48.6%; vaginal tablet crushed 50 microg and suspended in hydroxyethyl gel every 4 hours, 30.7%, P =.009; oral tablet 50 microg every 4 hours, 22.2%, P =.001; oral tablet crushed 50 microg every 4 hours, 15.5%, P <.001; dinoprostone gel, 33.0%, P =.022; intravenous oxytocin, 30.2%, P =.027; and spontaneous onset of labor, 23.3%, P <.001). Hyperstimulation occurred more often with dinoprostone gel (16.5%) than with other forms of induction or spontaneous labor. Hyperstimulation occurred significantly more often with vaginal misoprostol crushed tablet (7.9%) and vaginal misoprostol intact tablet (7.6%) than with crushed oral misoprostol (1.0%) (P =.016 and.018, respectively). There was a shorter time to tachysystole with increasing doses of vaginal misoprostol tablet (P =.01). CONCLUSION The incidence of tachysystole and hyperstimulation, and time to tachysystole, varied depending on the route and form of misoprostol given.
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Affiliation(s)
- J M Crane
- Department of Obstetrics and Gynecology, Health Care Corporation of St. John's, St. John's, Newfoundland, Canada
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Abstract
BACKGROUND Cytochrome oxidase-deficient mitochondrial myopathies represent a heterogeneous group of muscle disorders. Physical stress can cause life-threatening risks related to rhabdomyolysis or respiratory compromise. CASE A 21-year-old primigravida with cytochrome C oxidase-deficient mitochondrial myopathy who presented for obstetric care at 8 weeks' gestation complained of muscle fatigue and spasm after exertion. The increased metabolic demands of pregnancy led to worsening pain, muscle fatigue, and ultimately complete immobility. CONCLUSION Cytochrome oxidase-deficient mitochondrial myopathies are rare but serious complications of pregnancy.
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Affiliation(s)
- P S Soccio
- Department of Obstetrics and Gynecology, Memorial University of Newfoundland, 300 Prince Phillip Drive, St. John's, Newfoundland A1B 3V6, Canada
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Affiliation(s)
- D W Celander
- Department of Chemistry, Loyola University Chicago, Illinois 60626, USA
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Bennett KA, McConnell BJ, Fedak MA. Diurnal and seasonal variations in the duration and depth of the longest dives in southern elephant seals (Mirounga leonina): possible physiological and behavioural constraints. J Exp Biol 2001; 204:649-62. [PMID: 11171347 DOI: 10.1242/jeb.204.4.649] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study seeks to understand how the physiological constraints of diving may change on a daily and seasonal basis. Dive data were obtained from southern elephant seals (Mirounga leonina) from South Georgia using satellite relay data loggers. We analysed the longest (95th percentile) dive durations as proxies for physiological dive limits. A strong, significant relationship existed between the duration of these dives and the time of day and week of year in which they were performed. The depth of the deepest dives also showed a significant, but far less consistent, relationship with local time of day and season. Changes in the duration of the longest dives occurred irrespective of their depth. Dives were longest in the morning (04:00-12:00 h) and shortest in the evening (16:00-00:00 h). The size of the fluctuation varied among animals from 4.0 to 20.0 min. The daily pattern in dive depth was phase-shifted in relation to the diurnal rhythm in dive duration. Dives were deeper at midday and shallower around midnight. Greater daily changes in duration occurred in seals feeding in the open ocean than in those foraging on the continental shelf. The seasonal peak in the duration of the longest dives coincided with austral midwinter. The size of the increase in dive duration from autumn/spring to winter ranged from 11.5 to 30.0 min. Changes in depth of the longest dives were not consistently associated with particular times of year. The substantial diurnal and seasonal fluctuations in maximum dive duration may be a result of changes in the physiological capacity to remain submerged, in addition to temporal changes in the ecological constraints on dive behaviour. We speculate about the role of melatonin as a hormonal mediator of diving capability.
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Affiliation(s)
- K A Bennett
- NERC Sea Mammal Research Unit, Gatty Marine Laboratory, School of Biological Sciences, University of St Andrews, St Andrews KY16 8LB, Scotland
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Abstract
OBJECTIVES To evaluate women's sexual experience in pregnancy, and to describe their sources of information regarding sexuality during this period. DESIGN Cross-sectional study. SETTING The offices of obstetricians providing obstetric care in a tertiary care university hospital in St. John's, Newfoundland, Canada. POPULATION One hundred and forty-one pregnant women. METHODS Pregnant women anonymously completed self-administered questionnaires regarding sexuality and sexual activity during pregnancy. Responses were summarised using descriptive statistics, and comparisons were made between the trimesters of pregnancy. Multiple logistic regression was performed to assess the influences of a variety of factors on sexual activity. RESULTS Vaginal intercourse and sexual activity overall decreased throughout pregnancy (P = 0.004 and 0.05, respectively) with the trimester of pregnancy being the only independent predictor. Most women reported a decrease in sexual desire (58%). Overall, 49% of women worried that sexual intercourse may harm the pregnancy. Concerns regarding sexual activity leading to preterm labour or premature rupture of membranes increased as the pregnancy progressed (P < 0-001 and P = 0-001, respectively). Only 29% of women discussed sexual activity in pregnancy with their doctor and 49% of these women raised the issue first, with 34% feeling uncomfortable in bringing up the topic themselves. Most women (76%) who had not discussed these issues with their doctor felt they should be discussed. CONCLUSIONS A reduction in sexual activity, vaginal intercourse and sexual desire occurs in many women as pregnancy progresses. Both the woman and her partner have concerns regarding complications in the pregnancy as a result of sexual intercourse. The majority of women wish to discuss these issues with their doctor, but are not always comfortable raising the topic themselves.
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Affiliation(s)
- E Bartellas
- Department of Obstetrics and Gynaecology, Memorial University of Newfoundland, St. John's, Canada
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Butt KD, Bennett KA, Crane JM, Hutchens D, Young DC. Randomized comparison of oral misoprostol and oxytocin for labor induction in term prelabor membrane rupture. Obstet Gynecol 1999; 94:994-9. [PMID: 10576189 DOI: 10.1016/s0029-7844(99)00423-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To compare labor induction intervals between oral misoprostol and intravenous oxytocin in women who present at term with premature rupture of membranes. METHODS One hundred eight women were randomly assigned to misoprostol 50 microg orally every 4 hours as needed or intravenous oxytocin. The primary outcome measure was time from induction to vaginal delivery. Sample size was calculated using a two-tailed alpha of 0.05 and power of 80%. RESULTS Baseline demographic data, including maternal age, gestation, parity, Bishop score, birth weight, and group B streptococcal status, were similar. The mean time +/-standard deviation to vaginal birth with oral misoprostol was 720+/-382 minutes compared with 501+/-389 minutes with oxytocin (P = .007). The durations of the first, second, and third stages of labor were similar. There were no differences in maternal secondary outcomes, including cesarean birth (eight and seven, respectively), infection, maternal satisfaction with labor, epidural use, perineal trauma, manual placental removal, or gastrointestinal side effects. Neonatal outcomes including cord pH, Apgar scores, infection, and admission to neonatal intensive care unit were not different. CONCLUSION Although labor induction with oral misoprostol was effective, oxytocin resulted in a shorter induction-to-delivery interval. Active labor intervals and other maternal and neonatal outcomes were similar.
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Affiliation(s)
- K D Butt
- Department of Obstetrics and Gynecology, Grace General Hospital, Memorial University, St. John's, Newfoundland, Canada.
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Bennett KA, Butt K, Crane JM, Hutchens D, Young DC. A masked randomized comparison of oral and vaginal administration of misoprostol for labor induction. Obstet Gynecol 1998; 92:481-6. [PMID: 9764615 DOI: 10.1016/s0029-7844(98)00226-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To test the null hypothesis that administering misoprostol orally or vaginally will result in no difference in time to vaginal birth, and to determine whether different frequencies of tachysystole and hyperstimulation are associated with route of administration. METHODS Two hundred six women after 37 completed weeks' gestation who presented with an indication for induction were randomly assigned to receive misoprostol (50 microg) either orally or vaginally every 4 hours as needed to induce labor. Placebo use and allocation concealment accomplished blinding until data analysis was completed. Sample size was calculated to allow a two-tailed alpha of .05 and power (1-beta) of 80%. All fetal heart rate and uterine activity graphs were classified according to Curtis' criteria before induction groups were unmasked. RESULTS Analysis involved 104 women in the oral group and 102 in the vaginal group. The mean time (+/-standard deviation) to vaginal birth with oral misoprostol was 1072 (+/-593) minutes compared with 846 (+/-385) minutes with the vaginal protocol (P=.004). There were no significant differences in cesarean rate, epidural use, or neonatal outcomes. More frequent tachysystole for 20 minutes (P < .01) and hyperstimulation (P < .04) were observed with vaginal misoprostol. No neonatal asphyxia occurred in either group. CONCLUSION Misoprostol effectively induces labor, given orally or vaginally. There is a shorter interval to vaginal birth with vaginal application; however, the more frequent occurrence of fetal heart rate graph abnormalities in this group suggests that, until the optimal dosing interval for vaginal use is determined, the preferred route of misoprostol administration might be oral.
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Affiliation(s)
- K A Bennett
- Department of Obstetrics and Gynecology, Memorial University, St. John's, Newfoundland, Canada
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Wang S, True HL, Seitz EM, Bennett KA, Fouts DE, Gardner JF, Celander DW. Direct genetic selection of two classes of R17/MS2 coat proteins with altered capsid assembly properties and expanded RNA-binding activities. Nucleic Acids Res 1997; 25:1649-57. [PMID: 9092675 PMCID: PMC146620 DOI: 10.1093/nar/25.8.1649] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
RNA challenge phages are derivatives of bacteriophage P22 that enable direct genetic selection for a specific RNA-protein interaction. The bacteriophage P22 R17 encodes a wild-type R17 operator site and undergoes lysogenic development following infection of susceptible bacterial strains that express the R17/MS2 coat protein. A P22 R17 derivative with an OcRNA site (P22 R17 [A(-10)U]) develops lytically following infection of these strains. RNA challenge phages can be used to isolate second-site coat protein suppressors that recognize an OcRNA sequence by selecting for lysogens with a P22 R17 [Oc] phage derivative. The bacteriophage derivative P22 R17 [A(-10)U] was used in one such scheme to isolate two classes of genes that encode R17 coat proteins with altered capsid assembly properties and expanded RNA-binding characteristics. These mutations map outside the RNA-binding surface and include amino acid substitutions that interfere with interactions between coat protein dimers in the formation of the stable phage capsid. One class of mutants encodes substitutions at the highly conserved first and second positions of the mature coat protein. N-terminal sequence analysis of these mutants reveals that coat proteins with substitutions only at position 1 are defective in post-translational processing of the initiator methionine. All selected proteins possess expanded RNA-binding properties since they direct efficient lysogen formation for P22 R17 and P22 R17 [A(-10)U]; however, bacterial strains that express the protein mutants remain sensitive to lytic infection by other P22 R17 [Oc] bacteriophages. The described selection strategy provides a novel genetic approach to dissecting protein structure within RNA-binding proteins.
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Affiliation(s)
- S Wang
- Department of Microbiology and College of Medicine, University of Illinois at Urbana-Champaign, B103 Chemical and Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA
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Lee TQ, Anzel SH, Bennett KA, Pang D, Kim WC. The influence of fixed rotational deformities of the femur on the patellofemoral contact pressures in human cadaver knees. Clin Orthop Relat Res 1994:69-74. [PMID: 8168325] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Patellofemoral contact pressures resulting from fixed rotational deformities of the femur were studied in human cadaver knees. The increase in the degree of fixed rotational deformities of the femur results in a nonlinear increase in patellofemoral contact pressures on the contralateral facets of the patella (i.e., external rotational deformity resulted in a contact pressure increase on the medial facet, and internal rotational deformity resulted in a contact pressure increase on the lateral facet of the patella). With the initial isometric tension of 200 N in the quadriceps tendon for 30 degrees, 60 degrees, 90 degrees, and 120 degrees knee flexion, the peak contact pressure showed no significant differences between the medial and lateral facets of the patella in its anatomic position. At 20 degrees of rotational deformity of the femur, only a slight increase was noted for the tension in the quadriceps tendon and the patellofemoral contact pressures on the contralateral facets of the patella. However, at 30 degrees rotational deformity of the femur, both the external and internal rotational deformity of the femur showed a significant increase in the tension of the quadriceps tendon and the patellofemoral contact pressures on contralateral facets of the patella. The greatest increase in patellofemoral contact pressures was observed at 30 degrees and 60 degrees knee flexion for both the external and internal rotational deformity of the femur. The external rotational deformity of the femur for all knee flexion angles showed significantly higher peak patellofemoral contact pressure increases on the medial facet of the patella as compared with the lateral patellofemoral contact pressure increase resulting from internal rotational deformity of the femur.
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Affiliation(s)
- T Q Lee
- Department of Physical Medicine and Rehabilitation, Veterans Affairs Medical Center, Long Beach, California 90822
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Grines CL, Booth DC, Nissen SE, Gurley JC, Bennett KA, DeMaria AN. Acute effects of parenteral beta-blockade on regional ventricular function of infarct and noninfarct zones after reperfusion therapy in humans. J Am Coll Cardiol 1991; 17:1382-7. [PMID: 1673133 DOI: 10.1016/s0735-1097(10)80151-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although the mechanism is unknown, clinical trials have suggested that intravenous beta-adrenergic blockade may prevent early cardiac rupture after myocardial infarction. Previous studies have examined effects of beta-blockers on global left ventricular function after myocardial infarction; however, few data exist regarding their immediate effects on regional function or in patients after successful reperfusion. Therefore, 65 patients in whom thrombolysis with or without coronary angioplasty achieved reperfusion at 4.6 +/- 1.7 h from symptom onset were studied. Low osmolarity contrast ventriculograms were obtained immediately before and after administration of 15 mg of intravenous metoprolol (n = 54) or placebo (n = 11). Intravenous metoprolol immediately decreased heart rate (from 92 to 76 beats/min, p less than 0.0001), increased left ventricular diastolic volume (from 150 to 163 ml, p less than 0.001) and systolic volume (from 72 to 77 ml, p less than 0.0005) but did not change systolic and diastolic pressures. Although there was no difference in ejection fraction after metoprolol, centerline chord analysis revealed reduced noninfarct zone motion (from 0.41 to 0.12 SD/chord, p less than 0.05), improved infarct zone motion (from -3.1 to -2.9 SD/chord, p less than 0.01) and smaller circumferential extent of hypokinesia (from 30 to 27 chords, p less than 0.05). Patients with dyskinesia of the infarct zone had the most striking improvement in infarct zone wall motion. Because these changes occurred immediately after beta-blockade, they could not be attributed to myocardial salvage. No significant changes in heart rate, left ventricular volumes or regional wall motion were apparent in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C L Grines
- Division of Cardiology, College of Medicine, University of Kentucky, Lexington
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Abstract
Discriminant function analysis has been applied to numerous dimensions of the cranial and postcranial skeleton for sex determination of U.S. blacks and whites and is extended here to five measurements of the arm and wrist. These include maximum lengths of the long arm bones in addition to two measurements that reflect wrist breadth. Our results indicate that whites are more accurately classified than blacks, but seven of the 31 possible measurement combinations common to both groups yield functions with sex prediction accuracies comparable to most, but not all, functions based on other parts of the skeleton.
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Affiliation(s)
- D J Holman
- Department of Anthropology, Pennsylvania State University, University Park 16802
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Grines CL, Booth DC, Nissen SE, Gurley JC, Bennett KA, O'Connor WN, DeMaria AN. Mechanism of acute myocardial infarction in patients with prior coronary artery bypass grafting and therapeutic implications. Am J Cardiol 1990; 65:1292-6. [PMID: 2343816 DOI: 10.1016/0002-9149(90)91315-w] [Citation(s) in RCA: 67] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although acute myocardial infarction (AMI) is usually due to thrombotic occlusion when involving a native coronary artery, the mechanism responsible for AMI in patients with previous coronary artery bypass grafting (CABG) is not well understood. Since knowledge of pathophysiology of AMI may alter subsequent management, angiograms obtained between 1 hour and 7 days of AMI (median 1 day) were reviewed in 50 patients greater than 1 year after CABG. The culprit vessel was identified by the presence of residual stenosis and/or thrombus in the vessel supplying the infarct zone or by reviewing previous angiograms. The infarct vessel was identified as a vein graft in 38 (76%) patients, the native vessel in 8 patients (16%) and could not be accurately determined in 4 patients (8%). Among the 38 vein grafts suspected as the infarct vessel, unequivocal angiographic evidence of residual thrombus (filling defect/persistent staining) was present in 31 (82%) and was greater than 2 cm in length in 15 patients. Successful reperfusion occurred in only 2 of 8 (25%) grafts after intravenous thrombolytic therapy. Intragraft thrombolysis with or without additional angioplasty was successful at restoring flow in 8 of 10 (80%) grafts. Data indicate that in patients who have undergone previous CABG, AMI is usually caused by thrombotic occlusion of a saphenous vein graft and that conventional intravenous thrombolytic therapy may be inadequate to restore flow. The large mass of thrombus and absent flow in the graft may require subselective drug infusion, a higher thrombolytic dose or a mechanical means of recanalization.
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Affiliation(s)
- C L Grines
- Division of Cardiology, College of Medicine, University of Kentucky, Lexington
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Bennett KA, Grines CL. Current controversies in patient selection for thrombolytic therapy. J Emerg Nurs 1990; 16:191-4. [PMID: 2370724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Grines CL, Nissen SE, Booth DC, Branco MC, Gurley JC, Bennett KA, DeMaria AN. A new thrombolytic regimen for acute myocardial infarction using combination half dose tissue-type plasminogen activator with full dose streptokinase: a pilot study. KAMIT Study Group. J Am Coll Cardiol 1989; 14:573-80. [PMID: 2504797 DOI: 10.1016/0735-1097(89)90095-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Because a previous study utilizing a combination of recombinant tissue-type plasminogen activator (rt-PA) and urokinase demonstrated reduced reocclusion rates compared with rates obtained with rt-PA alone, this study was conducted to determine whether the combination of rt-PA and streptokinase might achieve similar results at reduced cost. Forty patients with acute myocardial infarction were treated with a 1 h infusion of rt-PA (50 mg) and streptokinase (1.5 million U) administered within 6 h (mean 3.6 +/- 1.2) of symptom onset. Emergency coronary arteriography revealed patency of the infarct-related artery in 30 (75%) of 40 patients. With the addition of coronary angioplasty in those who had unsuccessful thrombolytic reperfusion, the early patency rate was increased to 98%. In-hospital mortality rate (2.5%) and the incidence of significant bleeding requiring transfusion (15%) were low. Angiographically documented reocclusion of the infarct vessel occurred in 3 (8%) of 37 patients by day 7. Regional wall motion of the infarct zone improved by 0.9 +/- 0.9 SD/chord (p less than 0.0005), and ejection fraction increased 3.6 +/- 8% units (p less than 0.05) between immediate and day 7 studies. In contrast to the price of full dose rt-PA ($2,300) or rt-PA with urokinase ($3,500), the cost of this regimen was $1,230. This pilot study demonstrates that at half the cost, a combination of half dose rt-PA with full dose streptokinase offers high infarct vessel patency, recovery of ventricular function, a low rate of reocclusion and few bleeding complications.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C L Grines
- Department of Internal Medicine, University of Kentucky, Lexington
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Abstract
This study examines dental fluctuating asymmetry (FA) in two samples of fetal rhesus monkeys, one composed of 19 fetuses from diabetic mothers (FDM) and the other of 20 fetuses from nondiabetic mothers. Seventeen measurements were taken on the deciduous dentition of right and left mandibles. The degree of FA was assessed by comparing FDM to fetuses of normal mothers by correlation between right and left sides, and analysis of variation differences between right and left sides. Significant FA was found for three traits based on the correlation between right and left sides and for seven traits by the between-treatment ratio of variance between sides. Distal teeth, both within and outside of a morphologic field, exhibit significantly greater FA than mesial teeth. Our results support the hypothesis that developmental instability is detectable by dental FA.
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Bennett KA, Osborne RH. Interobserver measurement reliability in anthropometry. Hum Biol 1986; 58:751-9. [PMID: 3804296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
Rabbit ovum donors were superovulated with pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Ova were recovered 16-17 h post-hCG from oviducts immediately after killing and from excised oviducts held in saline 30 min at 33 degrees or 38 degrees C prior to ovum recovery. In vivo-capacitated spermatozoa were used to inseminate both groups of ova. Data revealed a decrease in fertilization rates following a 30-min delay at 38 degrees C in ovum recovery. Thus, 64% (44/69 ova) were fertilized with rapid recovery, whereas 43% (39/90 ova) were fertilized following a 30-min delay. The decrease in fertilization imposed by delay in ovum recovery was apparently overcome when oviduct storage was at 33 degrees C. Under these conditions, 69% of inseminated ova were fertilized. Ova inseminated with in vitro-capacitated sperm showed a similar response to delayed ovum recovery. Embryonic development in culture of ova obtained from mated does was not affected by delay in recovery at 33 degrees or 38 degrees C provided mated does had been injected only with hCG. Ova from mated does receiving both PMSG and hCG were adversely affected by a 38 degrees C delay. The data emphasize the importance of rapid ovum recovery from oviducts and suggest the possibility of altering conditions to overcome damaging effects of delayed recovery.
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Abstract
Levels of sex dimorphism among three related Japanese populations were calculated for 19 anthropometric variates. Two of the groups were born and raised contemporaneously in Japan; one remained there permanently (the sedentes) and the other migrated to Hawaii. The third group comprised the Hawaii-born offspring of the migrants. The results show a clear reduction in levels of sex dimorphism in the migrants as compared to both the sedentes and the Hawaii-born. Upon finding that the migrant females were generally larger than those of the other two groups, and after reviewing certain sociocultural phenomena related to the migration, it is hypothesized that the reduction in sex dimorphism was a transient change brought about by preferential choice of mates by the male migrants.
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Abstract
A procedure is developed and presented for the calculation of sex dimorphism in quantitative variates. Instead of expressing sex dimorphism by the male X/female X ratio, it deletes the area of overlap of the two curves and provides the proportion of males and females in terms of the areas under each curve. Examination of anthropometric variates among Eskimos from northwestern Alaska and the Hadza from Tanzania indicates that extremity measurements might be of special value for assessing the magnitude of sex dimorphism.
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Bennett KA, Cheverud JM, Booth SN. Deciduous tooth dimensions in fetal rhesus monkeys from mothers with induced diabetes. Am J Phys Anthropol 1981; 55:411-7. [PMID: 7270665 DOI: 10.1002/ajpa.1330550315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Thirty-four measurements of the deciduous dentition in 21 fetal rhesus monkeys from diabetic mothers (FDM) and 36 nondiabetic fetuses were compared in order to assess the effects of induced maternal diabetes on the teeth of third-trimester fetuses. After exclusion of 14 variates due to significant age-related variation, univariate statistical analysis suggested a trend toward smaller teeth in the FDMs. Multivariate discriminant function analysis indicated not only a clear separation between the two groups, with molar breadths and some incisor length and breadths serving as the best discriminators, but also that the deciduous dental dimensions in FDMs are smaller than in nondiabetic fetuses.
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Abstract
Members of the American Association of Physical Anthropologists were asked to supply information about their current programs and their own graduate training in order to compile a training directory and to analyze certain aspects of the discipline. The data indicate that the majority consider their graduate training to have been deficient, mainly in statistics, genetics, chemistry, physiology, and mathematics. The areas though most important for future research in physical anthropology include fields such a genetics, anatomy, ecology, physiology, and paleontology, although a great many individuals are engaged in teaching and research in other areas. A brief analysis of relative growth in the field over the last few decades indicates a serious imbalance between the number of new Ph.D.'s and available employment opportunities.
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Bennett KA. On the estimation of some demographic characteristics on a prehistoric population from the American Southwest. Am J Phys Anthropol 1973; 39:223-31. [PMID: 4356288 DOI: 10.1002/ajpa.1330390212] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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