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Oke KB, Cunningham CJ, Westley PAH, Baskett ML, Carlson SM, Clark J, Hendry AP, Karatayev VA, Kendall NW, Kibele J, Kindsvater HK, Kobayashi KM, Lewis B, Munch S, Reynolds JD, Vick GK, Palkovacs EP. Recent declines in salmon body size impact ecosystems and fisheries. Nat Commun 2020; 11:4155. [PMID: 32814776 PMCID: PMC7438488 DOI: 10.1038/s41467-020-17726-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 07/15/2020] [Indexed: 11/21/2022] Open
Abstract
Declines in animal body sizes are widely reported and likely impact ecological interactions and ecosystem services. For harvested species subject to multiple stressors, limited understanding of the causes and consequences of size declines impedes prediction, prevention, and mitigation. We highlight widespread declines in Pacific salmon size based on 60 years of measurements from 12.5 million fish across Alaska, the last largely pristine North American salmon-producing region. Declines in salmon size, primarily resulting from shifting age structure, are associated with climate and competition at sea. Compared to salmon maturing before 1990, the reduced size of adult salmon after 2010 has potentially resulted in substantial losses to ecosystems and people; for Chinook salmon we estimated average per-fish reductions in egg production (-16%), nutrient transport (-28%), fisheries value (-21%), and meals for rural people (-26%). Downsizing of organisms is a global concern, and current trends may pose substantial risks for nature and people.
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Affiliation(s)
- K B Oke
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95060, USA.
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, AK, 99801, USA.
| | - C J Cunningham
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, AK, 99801, USA
- Fisheries, Aquatic Science & Technology Laboratory, Alaska Pacific University, Anchorage, AK, 99508, USA
| | - P A H Westley
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA.
| | - M L Baskett
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, USA
| | - S M Carlson
- Environmental Science, Policy, and Management, University of California, Berkeley, CA, 94720, USA
| | - J Clark
- National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, CA, 93101, USA
| | - A P Hendry
- Department of Biology and Redpath Museum, McGill University, Montreal, QC, H3A 2K6, Canada
| | - V A Karatayev
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, USA
| | - N W Kendall
- Washington Department of Fish and Wildlife, Olympia, WA, 98501, USA
| | - J Kibele
- National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, CA, 93101, USA
| | - H K Kindsvater
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - K M Kobayashi
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95060, USA
| | - B Lewis
- Division of Commercial Fisheries, Alaska Department of Fish and Game, Anchorage, AK, 99518, USA
| | - S Munch
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95060, USA
- National Marine Fisheries Service, Fisheries Ecology Division, Southwest Fisheries Science Center, Santa Cruz, CA, 95060, USA
| | - J D Reynolds
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - G K Vick
- GKV & Sons, Contracting to Tanana Chiefs Conference, Fairbanks, AK, 99709, USA
| | - E P Palkovacs
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95060, USA.
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Zhang W, Ebert M, Chen B, Reynolds JD, Yan X, Du H, Banakar M, Tran DT, Debnath K, Littlejohns CG, Saito S, Thomson DJ. Integration of low loss vertical slot waveguides on SOI photonic platforms for high efficiency carrier accumulation modulators. Opt Express 2020; 28:23143-23153. [PMID: 32752315 DOI: 10.1364/oe.397044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
Silicon accumulation type modulators offer prospects of high power efficiency, large bandwidth and high voltage phase linearity making them promising candidates for a number of advanced electro-optic applications. A significant challenge in the realisation of such a modulator is the fabrication of the passive waveguide structure which requires a thin dielectric layer to be positioned within the waveguide, i.e. slotted waveguides. Simultaneously, the fabricated slotted waveguide should be integrated with conventional rib waveguides with negligible optical transition losses. Here, successful integration of polysilicon and silicon slot waveguides enabling a low propagation loss 0.4-1.2 dB/mm together with an ultra-small optical mode conversion loss 0.04 dB between rib and slot waveguides is demonstrated. These fabricated slot waveguide with dielectric thermal SiO2 layer thicknesses around 6 nm, 8 nm and 10 nm have been characterized under transmission electron microscopy allowing for strong carrier accumulation effects for MOS-capacitor electro-optic modulators.
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Osheim DL, Casper H, Colvin W, Emerick RJ, Everson RJ, Hamar D, Hunter T, Jain AV, Reynolds JD, Roof JE, Rottinghaus G, Stahr HM, Torma L. Atomic Absorption Determination of Serum Copper: Collaborative Study. J AOAC Int 2020. [DOI: 10.1093/jaoac/66.5.1140] [Citation(s) in RCA: 2] [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] [Indexed: 11/13/2022]
Abstract
Abstract
Preliminary to conducting a collaborative study on a method for copper in serum, methods used by a selected group of laboratories were surveyed. The responding laboratories were supplied with a Youden pair of bovine serum samples and requested to use their current method for serum copper. Results of the analyses and the methods used were evaluated; hypotheses were developed in our laboratory to explain some of the interlaboratory variation. For the AAS method chosen, each of 12 collaborating laboratories analyzed one blind duplicate and 2 Youden pair of serum samples. A commercially available external control serum with a certified level of copper and a 1000 mg copper/L standard were also submitted. The method requires the serum to be diluted 1 + 1 with distilled water and the standards to be diluted with 10% glycerin to approximate the viscosity of the diluted serum. The intralaboratory coefficients of variation (CV) ranged from 2.24 to 4.40% and the interlaboratory CV ranged from 2.56% to 6.05%. The method has been adopted official first action.
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Affiliation(s)
- David L Osheim
- U.S. Department of Agriculture, National Veterinary Services Laboratories, PO Box 844, Ames, IA 50010
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Perez-Protto SE, Reynolds JD, Nazemian R, You J, Hata JS, Latifi SQ, Lebovitz DJ. Peripheral tissue oxygenation and the number of organs transplanted per donor. Anaesth Intensive Care 2019; 46:601-607. [PMID: 30447670 DOI: 10.1177/0310057x1804600611] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Current donor management practices target macrohaemodynamic parameters, but it is unclear if this leads to improvements in microvascular perfusion and tissue oxygenation; the latter may have more impact on organ status. In a recent preclinical study we determined that brain death impaired tissue perfusion and oxygen utilisation in swine while pharmacologic correction of these deficits improved organ function and reduced markers of tissue injury. As a first step in translating the preclinical findings, we conducted a prospective observational study to determine if there was an association between peripheral tissue oxygenation (measured by near-infrared spectroscopy) in deceased by neurological criteria human donors and the number of organs transplanted. In 60 donors, the mean time-weighted average of tissue oxygenation was 87.5% (standard deviation, SD, 5.2%) and the average number of organs transplanted was 3.5 (SD 2); there was a positive linear relationship between these two parameters. A 5% rise in tissue oxygenation was associated with an increase of 0.47 organs transplanted (95% confidence intervals 0.16 to 0.78) after adjusting for age (<i>P</i>=0.004). No such correlations were observed for the macrohaemodynamic or macro-oxygenation parameters (including arterial blood oxygenation). The results of this clinical trial are consistent with our preclinical work and support the postulate that targeting the microvasculature to improve tissue perfusion and tissue oxygen delivery in human donors has the potential to increase the quantity of organs suitable for transplant.
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Affiliation(s)
- S E Perez-Protto
- Departments of Critical Care; Outcomes Research, Anesthesiology Institute; Cleveland Clinic, Cleveland, Ohio, USA
| | - J D Reynolds
- Anesthesiology and Perioperative Medicine, Institute for Transformative Molecular Medicine/School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - R Nazemian
- Institute for Transformative Molecular Medicine; Department of Anesthesia & Perioperative Medicine, University Hospitals Case Medical Center; Cleveland, Ohio, USA
| | - J You
- Outcomes Research, Anesthesiology Institute; Department of Qualitative Health Sciences; Cleveland Clinic, Cleveland, Ohio, USA
| | - J S Hata
- Departments of Critical Care; Outcomes Research, Anesthesiology Institute; Cleveland Clinic, Cleveland, Ohio, USA
| | - S Q Latifi
- Department of Pediatric Critical Care, Cleveland Clinic Children's Hospital; Lifebanc; Cleveland, Ohio, USA
| | - D J Lebovitz
- Critical Care Medicine, Akron Children's Hospital, Akron; Lifebanc; Cleveland, Ohio, USA
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Perez-Protto S, Nazemian R, Matta M, Patel P, Wagner KJ, Latifi SQ, Lebovitz DJ, Reynolds JD. The effect of inhalational anaesthesia during deceased donor organ procurement on post-transplantation graft survival. Anaesth Intensive Care 2018. [PMID: 29519220 DOI: 10.1177/0310057x1804600206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many deceased by neurologic criteria donors are administered inhalational agents during organ recovery surgery-a process that is characterised by warm and cold ischaemia followed by warm reperfusion. In certain settings, volatile anaesthetics (VA) are known to precondition organs to protect them from subsequent ischaemia-reperfusion injury. As such, we hypothesised that exposure to VA during organ procurement would improve post-graft survival. Lifebanc (organ procurement organisation [OPO] for NE Ohio) provided the investigators with a list of death by neurologic criteria organ donors cared for at three large tertiary hospitals in Cleveland between 2006 and 2016-details about the surgical recovery phase were extracted from the organ donors' medical records. De-identified data on graft survival were obtained from the United Network for Organ Sharing (UNOS). The collated data underwent comparative analysis based on whether or not VA were administered during procurement surgery. Records from 213 donors were obtained for analysis with 138 exposed and 75 not exposed. Demographics, medical histories, and organ procurement rates were similar between the two cohorts. For the primary endpoint, there were no significant differences observed in either early (30-day) or late (five-year) graft survival rates for kidney, liver, lung, or heart transplants. Our findings from this retrospective review of a relatively small cohort do not support the hypothesis that the use of VA during the surgical procurement phase improves graft survival. Reviews of larger datasets and/or a prospective study may be required to provide a definitive answer.
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Affiliation(s)
- S Perez-Protto
- Assistant Professor, Department of Critical Care, Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - R Nazemian
- MD, Institute for Transformative Molecular Medicine, Case Western Reserve University; Physician Resident, Department of Anesthesiology & Perioperative Medicine, University Hospitals Cleveland Medical Center; Cleveland, Ohio, USA
| | - M Matta
- Assistant Professor, Department of Pulmonary, Critical Care and Sleep Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - P Patel
- Clinical Fellow, Department of Anesthesiology & Perioperative Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - K J Wagner
- Assistant Professor, Department of Anesthesiology, Metro Health Medical Center, Cleveland, Ohio, USA
| | - S Q Latifi
- Attending Physician, Department of Pediatric Critical Care, Cleveland Clinic Children's Hospital; Co-Medical Director Lifebanc, Cleveland, Ohio, USA
| | - D J Lebovitz
- Attending Physician, Department of Critical Care, Akron Children's Hospital, Akron; Medical Director, Lifebanc, Cleveland; Ohio, USA
| | - J D Reynolds
- Institute for Transformative Molecular Medicine, Case Western Reserve University; Associate Professor, Department of Anesthesiology & Perioperative Medicine, University Hospitals Cleveland Medical Center; Cleveland, Ohio, USA
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Godwin SC, Dill LM, Krkošek M, Price MHH, Reynolds JD. Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice. J Fish Biol 2017; 91:41-57. [PMID: 28556094 DOI: 10.1111/jfb.13325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 11/16/2016] [Accepted: 03/29/2017] [Indexed: 06/07/2023]
Abstract
Daily growth rings were examined in the otoliths of wild juvenile sockeye salmon Oncorhynchus nerka to determine whether infection by ectoparasitic sea lice Caligus clemensi and Lepeophtheirus salmonis was associated with reduced host body growth, an important determinant of survival. Over 98% of the sea lice proved to be C. clemensi and the fish that were highly infected grew more slowly than uninfected individuals. Larger fish also grew faster than smaller fish. Finally, there was evidence of an interaction between body size and infection status, indicating the potential for parasite-mediated growth divergence.
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Affiliation(s)
- S C Godwin
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - L M Dill
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - M Krkošek
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
- Salmon Coast Field Station, Simoom Sound, BC, V0P 1S0, Canada
| | - M H H Price
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
- SkeenaWild Conservation Trust, Terrace, BC, V8G 1P2, Canada
| | - J D Reynolds
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
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Uemura K, Shimazutsu K, McClaine RJ, McClaine DJ, Manson RJ, White WD, Benni PB, Reynolds JD. Maternal and preterm fetal sheep responses to dexmedetomidine. Int J Obstet Anesth 2012; 21:339-47. [PMID: 22938943 DOI: 10.1016/j.ijoa.2012.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 06/12/2012] [Accepted: 06/19/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND The α(2) adrenergic receptor agonist dexmedetomidine has some unique pharmacologic properties that could benefit pregnant patients (and their fetuses) when they require sedation, analgesia, and/or anesthesia during pregnancy. The purpose of the present study was to delineate maternal and fetal responses to an intravenous infusion of dexmedetomidine. METHODS This study was conducted on surgically-recovered preterm sheep instrumented for physiologic recording and blood sampling. Maternal and fetal cardiovascular and blood gas parameters and fetal cerebral oxygenation levels were recorded before, during, and after 3h of dexmedetomidine infusion to the ewe at a rate of 1 μg/kg/h. RESULTS Drug infusion produced overt sedation but no apparent respiratory depression as evidenced by stable maternal arterial blood gases; fetal blood gases were also stable. The one blood parameter to change was serum glucose, By the end of the 3-h infusion, glucose increased from 49±10 to 104±33mg/dL in the ewe and from 22±3 to 48±16mg/dL in the fetus; it declined post-drug exposure but remained elevated compared to the starting levels (maternal, 63±12mg/dL, P=0.0497; and fetal, 24±4mg/dL, P=0.012). With respect to cardiovascular status, dexmedetomidine produced a decrease in maternal blood pressure and heart rate with fluctuations in uterine blood flow but had no discernable effect on fetal heart rate or mean arterial pressure. Likewise, maternal drug infusion had no effect on fetal cerebral oxygenation, as measured by in utero near-infrared spectroscopy. CONCLUSIONS Using a clinically-relevant dosing regimen, intravenous infusion of dexmedetomidine produced significant maternal sedation without altering fetal physiologic status. Results from this initial acute assessment support the conduct of further studies to determine if dexmedetomidine has clinical utility for sedation and pain control during pregnancy.
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Affiliation(s)
- K Uemura
- Department of Anesthesiology, Duke University Medical Centre, Durham, NC, USA
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Connors BM, Braun DC, Peterman R, Cooper AB, Reynolds JD, Dill LM, Ruggerone GT, Krkošek M. Migration links ocean-scale competition and local ocean conditions with exposure to farmed salmon to shape wild salmon dynamics. Conserv Lett 2012. [DOI: 10.1111/j.1755-263x.2012.00244.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Lengkeek W, Didderen K, Côté IM, van der Zee EM, Snoek RC, Reynolds JD. Plasticity in sexual size dimorphism and Rensch’s rule in Mediterranean blennies (Blenniidae). CAN J ZOOL 2008. [DOI: 10.1139/z08-103] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Comparative analyses of sexual size dimorphism (SSD) across species have led to the discovery of Rensch’s rule. This rule states that SSD increases with body size when males are the largest sex, but decreases with increasing size when females are larger. Within-species comparisons of SSD in fish are rare, yet these may be a valuable tool to investigate evolutionary patterns on a fine scale. This study compares SSD among closely related populations of three species of Mediterranean blennies (Blenniidae): Microlipophrys canevae (Vinciguerra, 1880), Parablennius incognitus (Bath 1968), and Aidablennius sphynx (Valenciennes, 1836). SSD varied more among populations than among species and Rensch’s rule was confirmed within two species. It is not likely that the variation among populations in SSD mirrors genetic variation, as many of the populations were in close proximity of one another, with a high potential for genetic exchange. This study complements larger scale analyses of other taxa and demonstrates the fine scale on which evolutionary processes responsible for Rensch’s rule may be operating.
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Affiliation(s)
- W. Lengkeek
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Alterra, Wageningen UR, Droevendaalsesteeg 3, 6708 PB, Wageningen, the Netherlands
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Marine Biology, University of Groningen, Kerklaan 30 9751 NN Haren, the Netherlands
| | - K. Didderen
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Alterra, Wageningen UR, Droevendaalsesteeg 3, 6708 PB, Wageningen, the Netherlands
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Marine Biology, University of Groningen, Kerklaan 30 9751 NN Haren, the Netherlands
| | - I. M. Côté
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Alterra, Wageningen UR, Droevendaalsesteeg 3, 6708 PB, Wageningen, the Netherlands
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Marine Biology, University of Groningen, Kerklaan 30 9751 NN Haren, the Netherlands
| | - E. M. van der Zee
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Alterra, Wageningen UR, Droevendaalsesteeg 3, 6708 PB, Wageningen, the Netherlands
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Marine Biology, University of Groningen, Kerklaan 30 9751 NN Haren, the Netherlands
| | - R. C. Snoek
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Alterra, Wageningen UR, Droevendaalsesteeg 3, 6708 PB, Wageningen, the Netherlands
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Marine Biology, University of Groningen, Kerklaan 30 9751 NN Haren, the Netherlands
| | - J. D. Reynolds
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Alterra, Wageningen UR, Droevendaalsesteeg 3, 6708 PB, Wageningen, the Netherlands
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
- Department of Marine Biology, University of Groningen, Kerklaan 30 9751 NN Haren, the Netherlands
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Shah MK, Shimazutsu K, Uemura K, Takahashi T, Stamler JS, Reynolds JD. Inclusion of an S-nitrosylating agent in the insufflating gas does not alter gastric activity in rats following pneumoperitoneum. Surg Endosc 2006; 21:1354-8. [PMID: 17180264 DOI: 10.1007/s00464-006-9107-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2006] [Accepted: 09/22/2006] [Indexed: 11/29/2022]
Abstract
BACKGROUND We have previously shown that mixing the S-nitrosylating agent ethyl nitrite with carbon dioxide can attenuate pneumoperitoneum-induced decreases in splanchnic blood flow, but it was unclear if this agent would alter gastric function. This question was answered using rats by assessing gastric emptying and gastrointestinal transit times following gavage with radioactive chromium. METHODS There were five experimental groups: absolute control, anesthesia control, and carbon dioxide alone or with 100 or 300 parts per million ethyl nitrite. The period of insufflation was 1 h, and all animals were euthanized 6.5 h after chromium administration. RESULTS The mean amount of radioactivity remaining in the stomach ranged between 16% and 27% of the total administered; these differences were not statistically significant (p > 0.05). Modest differences in chromium distribution were identified in the gastrointestinal tract, but for all treatments, the peak amount of radioactivity was located in the distal portion. Location of the peak, expressed as a percentage of total tract length, varied between 70% and 85% (p = 0.366). CONCLUSIONS This study found no adverse effect of ethyl nitrite on postoperative gastric emptying or gastrointestinal transit time following pneumoperitoneum. The findings support continued assessment of the clinical utility of ethyl nitrite in the setting of laparoscopic surgery.
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Affiliation(s)
- M K Shah
- Department of Anesthesiology, Duke Endosurgery Center, Room 119, Research Park 4, Durham, North Carolina 27710, United States
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Abstract
Empirical links between egg size and duration of parental care in fishes have generated a considerable amount of theory concerning life history evolution. However, to date, this link has not been investigated in relation to other important life-history traits such as clutch size and body size, or while controlling for shared ancestry between species. We provide the first phylogenetically based tests using a database with information on egg size, clutch size, body size and care duration in cichlid fishes (Cichlidae). Multiple regression analyses, based on independent contrasts on both the species and the genus level, showed that clutch size is the variable most closely related to duration of care. This pattern appeared to be driven by post-hatch care relationships. Our results show that, contrary to expectation, there is no positive link between egg size and care duration in Cichlidae. Instead, greater reproductive output through increased clutch size investment appears to have coevolved with greater care of offspring. We suggest that re-evaluation of the generality of current models of the evolution of egg size under parental care in fishes is needed.
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Affiliation(s)
- N Kolm
- Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, UK.
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Abstract
The negative relationship between offspring number and offspring size provides a classic example of the role of trade-offs in life history theory. However, the evolutionary transitions in egg size and clutch size that have produced this negative relationship are still largely unknown. Since body size may affect both of these traits, it would be helpful to understand how evolutionary changes in body size may have facilitated or constrained shifts in clutch and egg size. By using comparative methods with a database of life histories and a phylogeny of 222 genera of cichlid fishes, we investigated the order of evolutionary transitions in these traits in relation to each other. We found that the ancestral large-bodied cichlids first increased egg size, followed by a decrease in both body size and clutch size resulting in the common current combination of a small-bodied cichlid with a small clutch of large eggs. Furthermore, lineages that deviated from the negative relationship between clutch and egg size underwent different transitions in these traits according to their body size (large bodied genera have moved towards the large clutch/small egg end of the continuum and small bodied genera towards the small clutch/large egg end of the continuum) to reach the negative relationship between clutch size and egg size. Our results show that body size is highly important in shaping the negative relationship between clutch size and egg size.
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Affiliation(s)
- N Kolm
- Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, UK.
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Fuh E, de la Fuente S, Shah MK, Okodiko DK, Cummings TJ, Eubanks WS, Reynolds JD. Long-term behavioral assessment of guinea pigs following neonatal pneumoperitoneum. Surg Endosc 2005; 19:715-9. [PMID: 15759194 DOI: 10.1007/s00464-004-8181-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2004] [Accepted: 11/16/2004] [Indexed: 11/29/2022]
Abstract
BACKGROUND Using guinea pigs, we previously demonstrated that pneumoperitoneum during pregnancy produces behavioral deficits in the offspring. In the current study, the purpose was to determine if CO(2) pneumoperitoneum during the early postnatal period also produced behavioral anomalies. METHODS Following delivery, guinea pig pups were randomly assigned to one of three treatment groups: CO(2) pneumoperitoneum (P), laparotomy (L), or isolation control (I). Surgeries were performed on postnatal day (PND) 5 under isoflurane anesthesia; control pups were isolated from the dams for an equivalent period of time. On PNDs 10, 20, 40, and 60, behavior was assessed by monitoring locomotor and exploratory activity. RESULTS A total of 29 animals were studied. We observed no immediate morbidity or mortality and the manipulations did not appear to affect postnatal growth. On PND 10, pups in group P exhibited lower levels of locomotor activity compared to L and I neonates, but this difference resolved as the animals got older. Histologic assessment of the adult offspring brains revealed no evidence of neurologic injury. CONCLUSION These data suggest that unlike insufflation during pregnancy, neonatal pneumoperitoneum does not produce behavioral deficits.
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Affiliation(s)
- E Fuh
- Department of Surgery, Room 119, Research Park Building 4, Box 3094, Endosurgical Research Group, Duke University Medical Center, Durham, NC 27710, USA
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de la Fuente SG, Pinheiro J, Gupta M, Eubanks WS, Reynolds JD. Early postnatal behavior deficits after maternal carbon dioxide pneumoperitoneum during pregnancy. Surg Endosc 2003; 17:1823-5. [PMID: 12802645 DOI: 10.1007/s00464-002-8871-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2002] [Accepted: 11/21/2002] [Indexed: 11/26/2022]
Abstract
BACKGROUND In this study, we tested the hypothesis that maternal pneumoperitoneum produces early postnatal behavior deficits in the offspring. METHODS Time-dated pregnant guinea pigs were exposed to 45 min of carbon dioxide (CO2) pneumoperitoneum at a pressure of 7 mmHg. There was no manipulation of the control animals. On postnatal days (PND) 10 and 20, the behavior of their offspring was assessed by monitoring the locomotor activity of each of the pups in a 1 x 1 m chamber demarcated into 100 squares. Locomotor data was log-transformed and expressed as mean values (SD). RESULTS At PND 10, pneumoperitoneum offspring exhibited significantly higher levels of locomotor activity than the offspring of controls (1.81 +/- 0.48 vs 1.33 +/- 0.78). The pneumoperitoneum pups continued to exhibit hyperactive behavior at PND 20 (1.83 +/- 0.72 vs 1.20 +/- 0.72). CONCLUSIONS Maternal pneumoperitoneum produces postnatal hyperactivity in guinea pig offspring, suggesting that there may be long-term consequences associated with the physiologic changes produced in the fetus during CO2 insufflation.
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Affiliation(s)
- S G de la Fuente
- Department of Surgery, Duke University Medical Center, Box 3479, Durham, NC 27710, USA.
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Abstract
The Charadrii (shorebirds, gulls and alcids) are one of the most diverse avian groups from the point of view of sexual size dimorphism, exhibiting extremes in both male-biased and female-biased dimorphism, as well as monomorphism. In this study we use phylogenetic comparative analyses to investigate how size dimorphism has changed over evolutionary time, distinguishing between changes that have occurred in females and in males. Independent contrasts analyses show that both body mass and wing length have been more variable in males than in females. Directional analyses show that male-biased dimorphism has increased after inferred transitions towards more polygynous mating systems. There have been analogous increases in female-biased dimorphism after transitions towards more socially polyandrous mating systems. Changes in dimorphism in both directions are attributable to male body size changing more than female body size. We suggest that this might be because females are under stronger natural selection constraints related to fecundity. Taken together, our results suggest that the observed variation in dimorphism of Charadrii can be best explained by male body size responding more sensitively to variable sexual selection than female body size.
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Affiliation(s)
- P Lindenfors
- Department of Zoology, Stockholm University, Stockholm, Sweden.
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Loeliger M, Watson CS, Reynolds JD, Penning DH, Harding R, Bocking AD, Rees SM. Extracellular glutamate levels and neuropathology in cerebral white matter following repeated umbilical cord occlusion in the near term fetal sheep. Neuroscience 2003; 116:705-14. [PMID: 12573713 DOI: 10.1016/s0306-4522(02)00756-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Umbilical cord occlusion causes fetal hypoxemia which can result in brain injury including damage to cerebral white matter. Excessive glutamate release may be involved in the damage process. This study examined the relation between extracellular glutamate levels in the cerebral white matter of the ovine fetus during and after intermittent umbilical cord occlusion and the degree of resultant fetal brain injury. Fetal sheep underwent surgery for chronic catheterisation and implantation of an intra-cerebral microdialysis probe at 130 days of gestation (term approximately 147 days). Four days after surgery (day 1), seven fetuses were subjected to 5x2 min umbilical cord occlusions, and on the following day (day 2) they were subjected to either 4 or 5x4 min umbilical cord occlusions; seven fetuses served as controls. Microdialysis samples were collected before, during and after the umbilical cord occlusions to determine extracellular glutamate levels in the cerebral white matter. Fetal blood gas status was measured and the fetal electrocorticogram was recorded continuously. During the periods of umbilical cord occlusions on both days 1 and 2, fetal arterial oxygen saturation, arterial partial pressure of oxygen and arterial pH decreased (P<0.05) while arterial partial pressure of carbon dioxide increased (P<0.05). All fetuses showed episodes of isoelectric electrocortical activity during umbilical cord occlusions on both days 1 and 2. In fetuses with patent microdialysis probes there were marked increases of glutamate efflux in the cerebral white matter following umbilical cord occlusion. Fetal brains were removed at autopsy on day 5 and subjected to histological assessment. Brain damage was observed in all fetuses exposed to cord occlusion, particularly in the periventricular white matter, with the most extensive damage occurring in the fetuses with the greatest increases in glutamate levels. We conclude that, in the unanesthetised fetus in utero, glutamatergic processes are associated with umbilical cord occlusion-induced brain damage in the cerebral white matter.
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Affiliation(s)
- M Loeliger
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, 3010, Victoria, Australia.
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Olufolabi AJ, Booth JV, Reynolds JD. Remifentanil and pain relief in labour. Br J Anaesth 2002; 88:455-6; author reply 456. [PMID: 11990288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
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Abstract
There have been many major advances recently that have improved the identification and management of retinopathy of prematurity (ROP). This chapter describes the clinical features of ROP and then considers briefly the incidence and epidemiology of acute phase disease. This is followed by a discussion of the two ROP epidemics and ROP-induced disability in high, low and middle income countries, and how this has been impacted by treatment. The principles and specifics of screening for ROP are considered, focusing on certain topical issues such as whether one screening guideline suits all populations. Treatment has undergone several advances, so that now laser therapy has overtaken cryotherapy as the preferred mode of treatment, and treatment at an earlier stage is now being considered. Finally, the authors attempt to look into the future and wonder how the criteria for treatment will change, and whether innovations in ocular imaging will impact ROP screening in both high and middle income countries.
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Affiliation(s)
- A R Fielder
- Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College of Science, Technology and Medicine, Western Eye Hospital, London, UK.
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Brewer RP, Parra A, Borel CO, Hopkins MB, Reynolds JD. Intravenous magnesium sulfate does not increase ventricular CSF ionized magnesium concentration of patients with intracranial hypertension. Clin Neuropharmacol 2001; 24:341-5. [PMID: 11801809 DOI: 10.1097/00002826-200111000-00005] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Magnesium sulfate has attracted interest as a potential neuroprotectant but passage of magnesium ion into the central nervous system has not been well documented. For this study, we quantified plasma and cerebrospinal fluid (CSF) ionized magnesium concentration after systemic magnesium sulfate infusion in patients with intracranial hypertension. Patients ( N = 9) received an intravenous infusion of 5 g/20 mmol magnesium sulfate (125 mL of a 4% wt/vol solution) over 30 minutes. Before and after dosing, CSF (from an indwelling ventricular catheter) and blood samples were collected at hourly intervals. Ionized magnesium concentration in all samples was determined using an electrolyte analyzer. Baseline plasma and CSF ionized magnesium concentrations were 0.58 +/- 0.05 and 0.82 +/- 0.06 mmol/L, respectively. Intravenous magnesium sulfate infusion significantly increased plasma ionized magnesium concentration (peak, 0.89 +/- 0.11 mmol/L), but CSF magnesium levels did not change during the 4-hour study. Systemic administration of magnesium sulfate failed to increase CSF ionized magnesium concentration in patients with intracranial hypertension despite increasing plasma magnesium levels by >50%.
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Affiliation(s)
- R P Brewer
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Garcia-Oria M, Ali A, Reynolds JD, Clary E, Gandsas A, Cummings T, McMahon RL, Bruch S, Fina M, Ko A, Eubanks S. Histologic evaluation of fetal brains following maternal pneumoperitoneum. Surg Endosc 2001; 15:1294-8. [PMID: 11727136 DOI: 10.1007/s004640080040] [Citation(s) in RCA: 5] [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] [Received: 06/14/2000] [Accepted: 11/06/2000] [Indexed: 11/27/2022]
Abstract
BACKGROUND The purpose of this study was to determine if maternal pneumoperitoneum with carbon dioxide (CO2) produces evidence of central nervous system (CNS) injury in preterm fetal guinea pigs. METHODS Thirty pregnant guinea pigs at gestational day (GD) 45 were assigned at random to one of three treatment groups: anesthesia only, CO2 pneumoperitoneum (5 mmHg), or laparotomy. Dams were killed 3 or 5 days postprocedure and fetal brains (83 total) harvested and fixed for subsequent histopathologic evaluation. For comparative purposes, histologic features of fetal guinea pig brain injury were defined from examination of fetal brains harvested from an additional dam that underwent laparotomy with 20 min of uterine arterial occlusion. RESULTS Carbon dioxide pneumoperitoneum did not increase maternal/fetal morbidity. No evidence of brain injury was found in fetuses from any of the treatment groups. CONCLUSION Carbon dioxide pneumoperitoneum at 5 mmHg for 40 min in the pregnant guinea pig does not produce evidence of fetal brain injury.
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Affiliation(s)
- M Garcia-Oria
- Department of Surgery, Duke University Medical Center, Endosurgery Research Laboratory, Durham, NC, 27710, USA
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Abstract
OBJECTIVE To objectively assess the effect of light reduction as an isolated environmental intervention on neonatal morbidity. STUDY DESIGN Randomized multicenter trial. Neonates < 1251 g birth weight and < 31 weeks gestational age were randomly assigned to receive goggles or to a control group. Goggles that reduced visible light by 97% were placed within 24 hours of birth and remained in use until 31 weeks postmenstrual age or for a minimum of 4 weeks. RESULTS Four hundred nine infants were enrolled, and outcome data are reported for 359 surviving infants. There were no significant differences between the groups in weight gain, duration of oxygen therapy, mechanical ventilation, or hospital stay either in the unadjusted analyses or in the analyses adjusted for birth weight, gestational age, race, sex, and inborn (born in study hospital) status. There was no difference between the groups in the incidence of intracranial hemorrhage. CONCLUSIONS This randomized trial of continuous light reduction in the first few weeks of life for very low birth weight infants showed no effect on medical outcomes.
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Affiliation(s)
- K A Kennedy
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA
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Abstract
Retinopathy of prematurity (ROP) is a major problem in both highly developed countries and countries with emerging technology. The incidence of ROP has been stable over the last 2 decades despite improvements in neonatology. Threshold ROP occurs in about 5% of premature infants in the US with birthweights <1.25kg. Despite treatment, a sizable minority will become blind (up to 20 to 30%). The pathophysiology of ROP can be separated into 2 phases. Phase I is hyperoxia-vasocessation. Phase II is hypoxia-vasoproliferation. The former occurs immediately following premature birth. The provision of supplemental oxygen causes retinal hyperoxia, a down regulation of vascular endothelial growth factor (VEGF) and a consequent cessation of normal retinal vascularisation. Systemic factors and increasing retinal metabolic demands cause a shift to phase II when a relative retinal hypoxia develops. This hypoxia stimulates VEGF production, leading to renewed vascularisation. This can be the resumption of normal vascularisation or abnormal neovascularisation, depending on local retinal responses. The management of ROP begins with a reliable evidence-based screening protocol. All interested parties must cooperate in developing and implementing foolproof screening protocols. Hospital officials, nursery personnel, neonatologists and ophthalmologists all have areas of responsibility in ensuring adequate screening. ROP management involves prevention, interdiction and correction. Prevention includes: adequate prenatal care which minimises premature birth, and appropriate systemic intensive care which lessens the tissue hyperoxia/hypoxia swings. Pharmacological vitamin E supplementation has largely been abandoned and ambient light reduction has been shown to be ineffective. The value of inositol supplementation and angiogenesis inhibitors in preventing ROP is presently under investigation. Interdiction concentrates on ablation of the peripheral avascular retina, thus dramatically decreasing VEGF production. Both cryotherapy and laser photocoagulation are effective; however, unfortunately, poor outcomes persist despite treatment. Supplemental oxygen administration has so far proven ineffective in limiting ROP progression. Finally, correction focuses on vitrectomy/retinal detachment repair. While anatomically successful, this procedure is often unsuccessful in terms of restoration of vision (<5% success rate). In conclusion, despite improvements in neonatology, ROP, potentially leading to blindness, continues to be a common problem associated with prematurity. Future management success must concentrate on discovering new modes of treatment, especially prevention.
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Affiliation(s)
- J D Reynolds
- State University of New York at Buffalo, Children's Hospital, 14222, USA
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Gouin N, Grandjean F, Bouchon D, Reynolds JD, Souty-Grosset C. Population genetic structure of the endangered freshwater crayfish Austropotamobius pallipes, assessed using RAPD markers. Heredity (Edinb) 2001; 87:80-7. [PMID: 11678990 DOI: 10.1046/j.1365-2540.2001.00909.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [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: 11/20/2022] Open
Abstract
Random amplified polymorphic DNA (RAPD) analysis was performed to characterize the genetic diversity of Austropotamobius pallipes, a threatened freshwater crayfish native to Europe. Four decamer primers which generated six unambiguous polymorphic bands were used to analyse crayfish from 21 populations sampled in the major part of its range. Genetic diversity within populations of A. pallipes, estimated by Shannon's diversity index, ranged from 0 to 0.446 with a mean of 0.159. A UPGMA dendrogram constructed from pairwise PhiST values between populations, revealed three clusters corresponding to populations sampled in the southern, northwestern and eastern part of its range. AMOVA analysis revealed a high genetic structure of A. pallipes populations PhiST=0.814, with 73.11% of the genetic variation distributed between these clusters. It suggests a historical geographical separation of these groups into three refugial areas, probably in the Rhine, Mediterranean and Atlantic basins during recent glaciations. The close genetic relationships between English and western French populations are in accordance with a natural postglacial origin of English populations from individuals having survived in an Atlantic refugium. However, the present results suggest that the Irish stock originated from a human translocation of individuals from an Atlantic refugium.
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Affiliation(s)
- N Gouin
- Laboratoire de Génétique et Biologie des Populations de Crustacés, UMR CNRS 6556, Université de Poitiers, 40 Avenue du recteur Pineau, F-86022 Poitiers cedex, France
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Storb U, Peters A, Kim N, Shen HM, Bozek G, Michael N, Hackett J, Klotz E, Reynolds JD, Loeb LA, Martin TE. Molecular aspects of somatic hypermutation of immunoglobulin genes. Cold Spring Harb Symp Quant Biol 2001; 64:227-34. [PMID: 11232290 DOI: 10.1101/sqb.1999.64.227] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- U Storb
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637, USA
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Msall ME, Phelps DL, DiGaudio KM, Dobson V, Tung B, McClead RE, Quinn GE, Reynolds JD, Hardy RJ, Palmer EA. Severity of neonatal retinopathy of prematurity is predictive of neurodevelopmental functional outcome at age 5.5 years. Behalf of the Cryotherapy for Retinopathy of Prematurity Cooperative Group. Pediatrics 2000; 106:998-1005. [PMID: 11061766 DOI: 10.1542/peds.106.5.998] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The purpose of this study was to assess the relation between neonatal retinopathy of prematurity (ROP) in very low birth weight infants and neurodevelopmental function at age 5.5 years. METHODS Longitudinal follow-up of children occurred in 2 cohorts of the Multicenter Cryotherapy for Retinopathy of Prematurity Study. The extended natural history cohort followed 1199 survivors of <1251 g birth weight from 5 centers. The threshold randomized cohort (ThRz) followed 255 infants <1251 g from 23 centers who developed threshold ROP and who consented to cryotherapy to not more than 1 eye. At 5.5 years both cohorts had ophthalmic and acuity testing and neurodevelopmental functional status determined with the Functional Independence Measure for Children (WeeFIM). RESULTS Evaluations were completed on 88.7% of the extended natural history cohort; 87% had globally normal functional skills (WeeFIM: >95). As ROP severity increased, rates of severe disability increased from 3.7% among those with no ROP, to 19.7% of those with threshold ROP. Multiple logistic regression analysis demonstrated that better functional status was associated with favorable visual acuity, favorable 2-year neurological score, absence of threshold ROP, having private health insurance, and black race. Evaluations were completed on 87.4% of the ThRz children. In each functional domain, the 134 children with favorable acuity in their better eye had fewer disabilities than did the 82 children with unfavorable acuity: self-care disability 25.4% versus 76.8%, continency disability 4.5% versus 50.0%, motor disability 5.2% versus 42.7%, and communicative-social cognitive disability 22.4% versus 65.9%, respectively. CONCLUSION Severity of neonatal ROP seems to be a marker for functional disability at age 5. 5 years among very low birth weight survivors. High rates of functional limitations in multiple domains occur in children who had threshold ROP, particularly if they have unfavorable visual acuity.
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Affiliation(s)
- M E Msall
- Child Development Center, Hasbro Children's Hospital, Brown University School of Medicine, Providence, Rhode Island, USA
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Abstract
IMPLICATIONS In this preliminary investigation, we evaluated the safety and analgesic efficacy of IV remifentanil for labor pain. Four women were studied, and then the trial was terminated because administration of this novel synthetic opioid produced significant maternal side effects in the absence of effective pain control.
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Affiliation(s)
- A J Olufolabi
- Division of Women's Anesthesia, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA.
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Perdices A, Doadrio I, Côté IM, Machordom A, Economidis P, Reynolds JD. Genetic Divergence and Origin of Mediterranean Populations of the River BlennySalaria fluviatilis(Teleostei: Blenniidae). COPEIA 2000. [DOI: 10.1643/0045-8511(2000)000[0723:gdaoom]2.0.co;2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
Charadrii (shorebirds, gulls, and alcids) have an unusual diversity in their sexual size dimorphism, ranging from monomorphism to either male-biased or female-biased dimorphism. We use comparative analyses to investigate whether this variation relates to sexual selection through competition for mates or natural selection through different use of resources by males and females. As predicted by sexual selection theory, we found that in taxa with socially polygynous mating systems, males were relatively larger than females compared with less polygynous species. Furthermore, evolution toward socially polyandrous mating systems was correlated with decreases in relative male size. These patterns depend on the kinds of courtship displays performed by males. In taxa with acrobatic flight displays, males are relatively smaller than in taxa in which courtship involves simple flights or displays from the ground. This result remains significant when the relationship with mating system is controlled statistically, thereby explaining the enigma of why males are often smaller than females in socially monogamous species. We did not find evidence that evolutionary changes in sexual dimorphism relate to niche division on the breeding grounds. In particular, biparental species did not have greater dimorphism in bill lengths than uniparental species, contrary to the hypothesis that selection for ecological divergence on the breeding grounds has been important as a general explanation for patterns of bill dimorphism. Taken together, these results strongly suggest that sexual selection has had a major influence on sexual size dimorphism in Charadrii, whereas divergence in the use of feeding resources while breeding was not supported by our analyses.
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Affiliation(s)
- T Székely
- Centre for Behavioural Biology, School of Biological Sciences, University of Bristol, United Kingdom.
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Booth JV, Lindsay DR, Olufolabi AJ, El-Moalem HE, Penning DH, Reynolds JD. Subarachnoid meperidine (Pethidine) causes significant nausea and vomiting during labor. The Duke Women's Anesthesia Research Group. Anesthesiology 2000; 93:418-21. [PMID: 10910491 DOI: 10.1097/00000542-200008000-00020] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The combined spinal-epidural (CSE) technique using bupivicaine-fentanyl has become an established method of pain control during parturition. One limitation is the relatively short duration of effective analgesia produced by bupivicaine-fentanyl. In contrast, subarachnoid meperidine has been shown to provide a long duration of anesthesia in nonobstetric patients. Therefore, the authors tested the hypothesis that subarachnoid meperidine produces a significant increase in the duration of analgesia compared with bupivicaine-fentanyl. METHODS Based on a power analysis of preliminary data, the authors intended to recruit 90 patients for the study, randomized to three groups: 2.5 mg bupivicaine-25 microg fentanyl, 15 mg meperidine, or 25 mg meperidine. However, after enrolling 34 patients, the study was discontinued because of a significant increase in nausea or vomiting in the study patients. RESULTS Nausea or vomiting was substantially increased in both meperidine groups compared with the bupivicaine-fentanyl group: 16 with nausea or vomiting in the meperidine groups (n = 21), compared with 1 in the bupivicaine-fentanyl group (n = 11), P = 0.0011. The mean duration of analgesia provided by 25 mg meperidine was 126 +/- 51 min, compared with 98 +/- 29 min for bupivicaine-fentanyl and 90 +/- 67 min for 15 mg meperidine. These data were not significant (P = 0.27). CONCLUSIONS Although intrathecal meperidine could potentially prolong subarachnoid analgesia during labor, its use was associated with a significant incidence of nausea or vomiting. These data do not support the use of subarachnoid meperidine in doses of 15 or 25 mg for labor analgesia.
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Affiliation(s)
- J V Booth
- Division of Women's Anesthesia, the Departments of Anesthesiology and Biostatistics, Duke University Medical Center, Durham, NC 27710, USA.
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Abstract
Behaviour can be a key component of animal population ecology yet the population consequences of behavioural decisions are poorly understood. We conducted a behavioural and demographic study of the bitterling Rhodeus sericeus, a freshwater fish that spawns in live unionid mussels. We used a population model incorporating game theory decisions and measurements of demographic parameters in order to provide predictions of population size among 13 populations of this fish. Our model predicted that the observed behavioural spawning decisions, while maximizing individual fitness, cause a significant 6% reduction in population size compared with randomly distributed spawnings. We discuss our findings in the context of the population consequences of adaptive behaviour.
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Affiliation(s)
- C Smith
- School of Biological Sciences, Queen Mary and Westfield College, University of London, UK.
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Reynolds JD, Grubbs EG, Dexter F, Punnahitananda S, Dense TA, Penning DH. Acute cord occlusion increases blood ionized magnesium concentration in preterm fetal sheep during maternal magnesium sulfate exposure. Can J Physiol Pharmacol 2000; 78:301-6. [PMID: 10772057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
This study tested the hypothesis that a pathophysiologic insult to the fetus that decreases pH (umbilical cord occlusion) produces an increase in physiologically active (i.e., ionized) magnesium concentration. Preterm pregnant sheep (n = 7) were instrumented with maternal and fetal catheters and an inflatable vascular occluder was placed around the umbilical cord. After a 2-day recovery period, each ewe received a 4-g loading dose, followed by continuous intravenous infusion of 1 g magnesium sulfate/h. After 48 h, an episode of acute fetal distress was produced by inflation of the umbilical occluder for 10 min. Maternal and fetal arterial blood samples were collected at regular intervals to quantitate ionized magnesium concentration and monitor physiologic status. Magnesium sulfate infusion increased maternal and fetal blood ionized magnesium concentration. In vitro blood analysis demonstrated that there was a linear inverse correlation (r2 = 0.99) between fetal sheep blood pH and ionized magnesium concentration. In vivo, 10 min of umbilical cord occlusion produced an increase in fetal blood ionized magnesium concentration in all animals (P = 0.02) that was temporally related to the decrease in fetal blood pH. Whether this increase in physiologically active magnesium concentration is beneficial (via neuroprotection) or deleterious (via suppression of stress response) to the distressed fetus remains to be determined.
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Affiliation(s)
- J D Reynolds
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
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Spear-Smith J, Brien JF, Grafe M, Allrich R, Reynolds JD. Chronic ethanol exposure during late gestation produces behavioral anomalies in neonatal lambs. Neurotoxicol Teratol 2000; 22:205-12. [PMID: 10758349 DOI: 10.1016/s0892-0362(99)00059-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 11/25/2022]
Abstract
A total of 45 pregnant ewes were assigned to one of three treatment groups: 1 g ethanol/kg maternal body weight (n = 18); pair-fed control (n = 15); and ad lib control (n = 12). Dosing started at gestational day (GD) 106, and was administered every other day until GD 134. Parturition occurred between GD 144 and 147. Analysis of the placentas indicated that ethanol exposure decreased cotyledon diameter and cotyledon weight compared to the control groups (p < 0. 05). At birth, lambs were given a Vigor Score and then behavior was assessed using a videotape monitoring system for 24 h. Offspring in the ethanol treatment group were significantly less vigorous at birth (p < 0.05). This finding reversed during the subsequent 24 h such that the ethanol-exposed lambs were significantly more active (p = 0.001) than the control lambs. Morphometric and histologic examination of the cerebral cortex and hippocampus revealed no differences amongst the three treatment groups. Collectively, the data demonstrate that moderate ethanol exposure during the third-trimester equivalent of gestation can produce placental dysmorphology and postnatal behavioral anomalies in neonatal lambs in the absence of gross neurologic injury.
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Affiliation(s)
- J Spear-Smith
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
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Abstract
During the breeding season an individual's access to mates may be affected by operational sex ratios, causing strong variation in mating success. We manipulated adult sex ratios of the European lobster, Homarus gammarus, to test the predictions of models that relate sexual competition to (1) the sex ratio, (2) the time that an individual is not available to mate and (3) 'collateral investment', whereby two males contribute to a single clutch. The model predictions proved to be relatively insensitive to collateral investment. Male-male competition predominated in the male-biased but not in the female-biased sex ratio. This matches the predictions of one model that incorporates an extended period of female receptivity because the time that a male was unavailable to mate was small compared to the time spent by females in cohabitation and parental care. Although females increased their competitiveness when males were in the minority, male competition remained high. The insensitivity of male-male competition to sex ratios may be due to an upper limit to the costs that males can afford when there is a serious risk of injury, preventing males from increasing their aggression when females are in short supply. Copyright 1999 The Association for the Study of Animal Behaviour.
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Affiliation(s)
- VJ Debuse
- School of Biological Sciences, University of East Anglia
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Reynolds JD. Female preference for preferred males is reversed under low oxygen conditions in the common goby (Pomatoschistus microps). Behav Ecol 1999. [DOI: 10.1093/beheco/10.2.149] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [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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Penning DH, Dexter F, Henderson JL, Chestnut DH, Reynolds JD. Bolus maternal cocaine administration does not produce a large increase in fetal sheep cerebral cortical glutamate concentration. Neurotoxicol Teratol 1999; 21:177-80. [PMID: 10192278 DOI: 10.1016/s0892-0362(98)00050-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Human cocaine use during pregnancy may result in postnatal neurologic dysfunction and abnormal behavior. L-Glutamate, the major excitatory neurotransmitter in the brain, plays an important role in cerebral cortical development. An optimal level of glutamate is required for normal neuronal development. We tested whether acute cocaine exposure produces large increases in glutamate release in the intact cerebral cortex of the near-term fetal sheep. Cocaine 3.0 mg kg(-1) IV bolus produced the expected increase in maternal and fetal mean arterial pressure, increase in fetal heart rate, decrease in uterine blood flow, and decrease in fetal arterial blood pO2 (N = 5). The percentage increases in extracellular glutamate concentration in the fetal cerebral cortex measured by in utero microdialysis were 7%, 15%, 17%, 17%, and 43% in each fetus (upper 95% confidence bound for the median = 43%). We conclude that if cocaine increases glutamate concentration in the developing cerebral cortex, the increase in magnitude is small relative to the changes produced by other interventions such as ethanol or umbilical cord occlusion. Mechanisms other than increases in cerebral cortical glutamate concentration probably contribute to the neurologic injury associated with prenatal cocaine exposure.
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Affiliation(s)
- D H Penning
- Department of Anesthesiology, Duke University, Durham, NC, USA.
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Dobson V, Quinn GE, Siatkowski RM, Baker JD, Hardy RJ, Reynolds JD, Trese MT, Tung B. Agreement between grating acuity at age 1 year and Snellen acuity at age 5.5 years in the preterm child. Cryotherapy for Retinopathy of Prematurity Cooperative Group. Invest Ophthalmol Vis Sci 1999; 40:496-503. [PMID: 9950610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
PURPOSE To examine the relation between grating acuity at age 1 year and Snellen acuity and grating acuity at 5.5 years, in preterm children with birth weights less than 1251 g. METHODS Subjects were participants in the multicenter study of Cryotherapy for Retinopathy of Prematurity. The Teller acuity card (TAC; Vistech Consultants, Dayton, OH) procedure was used to measure monocular grating acuity in children at ages 1 and 5.5 years. Early-treatment diabetic retinopathy study (ETDRS) charts were used to measure the childrens' monocular recognition (Snellen) acuity at age 5.5 years. Data are presented for 575 eyes with measurable TAC grating acuity at 1 year and 111 eyes that had no measurable acuity at 1 year. RESULTS Among eyes with normal acuity at 1 year, 86.8% showed normal Snellen acuity, and 94.3% showed normal grating acuity at 5.5 years. Among eyes that were blind (i.e., had no measurable TAC grating acuity) at 1 year, 96.8% showed no quantifiable Snellen acuity, and 89.2% showed no quantifiable grating acuity at 5.5 years. Only 2.4% of eyes had acuity in the range between normal and blind at 1 year (i.e., measurable grating acuity <1.6 cyc/deg); thus, the predictive value of acuity scores in this range could not be determined. Correlation analysis indicated that the relative position within the normal range of an eye's grating acuity score at 1 year was not predictive of the relative position within the normal range of that eye's acuity score at 5.5 years. CONCLUSIONS Among a large population of low-birth-weight infants, eyes with normal grating acuity at age 1 year generally showed normal Snellen and grating acuity at age 5.5 years, and eyes that had no quantifiable acuity at 1 year remained blind at 5.5 years. Relative position of an eye's acuity score within the normal range was not predictive of the relative position of that eye's later acuity score.
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Affiliation(s)
- V Dobson
- Department of Ophthalmology, University of Arizona, Tucson 85719-3758, USA
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Abstract
This study examines the effects of harsh environmental conditions on life history trade-offs in parental care in a marine fish, the common goby, Pomatoschistus microps. We compared male parental care and hatching success over two sequential brood cycles in fish breeding in conditions of either low dissolved oxygen or normal levels of oxygen. Males compensated for a low oxygen environment by increasing the time they spent fanning water over their eggs, as well as their fanning tempo. They also increased the frequency of egg-directed activities and decreased nest-building activities. Males in the low oxygen treatment lost more weight than control fish during the first spawning, and were more likely to abandon care during the second spawning. Males that completed care under low oxygen conditions did not differ from control males in the hatching success of their offspring or the size of young at hatching, but hatching started on average 1 day later. Thus, greater parental allocations to offspring while breeding in a harsh environment led to reduced future allocations. Copyright 1999 The Association for the Study of Animal Behaviour.
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Affiliation(s)
- JC Jones
- School of Biological Sciences, University of East Anglia
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Abstract
This study examines the role of dissolved oxygen in modifying female mate choice in the common goby, Pomatoschistus microps. Experimental manipulations of nests showed that under normal (saturated) oxygen conditions, females preferred to spawn in nests with the most elaborate construction, that is, those with the most sand on top and the smallest entrance. Such manipulated nests proved less vulnerable to detection by an egg predator, the shore crab, Carcinus maenas, but these small entrances may reduce oxygenation of eggs. Indeed, in a low oxygen environment females with a choice between nests of high build and nests of low build did not significantly prefer either. This may have been due to weakened preference or perhaps detection of a mismatch between the male's parental quality and the increased ventilation needs of eggs when nest entrance sizes are small and ambient oxygen levels are low. When nests were not manipulated, those males that built small entrances fanned their eggs more often, such that hatching success in the absence of a predator was not related to the initial size of the nest entrance area. Thus, under normal oxygen conditions males may initially build nests with the smallest entrance they are capable of ventilating successfully, and females choosing such males gain from nest camouflage. Under low oxygen, the risk that manipulated males may be unable to compensate fully may outweigh such benefits, and females may use other criteria that signal willingness to provide parental care. Copyright 1999 The Association for the Study of Animal Behaviour.
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Affiliation(s)
- JC Jones
- School of Biological Sciences, University of East Anglia
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Kokko H, Sutherland WJ, LindstrÖm J, Reynolds JD, Mackenzie A. Individual mating success, lek stability, and the neglected limitations of statistical power. Anim Behav 1998; 56:755-612. [PMID: 9784227 DOI: 10.1006/anbe.1998.0815] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The evolution of leks (aggregations of males displaying to females) cannot be explained solely by an increasing average gain in matings for each male as group size increases. This is because the mating skew, that is, the inequality among males in mating success, is often high and may vary with lek size. Here, we show that the common observation that matings become more evenly divided as lek size increases is also insufficient to explain by itself the benefits of aggregating. The benefits to individual males are highly sensitive to the exact relationship between mating skew and lek size, and very similar relationships can lead to opposite predictions concerning individual benefits. With data on published mating success for 18 species (71 leks), we show that different species have very similar skew versus lek size relationships. With current sample sizes, however, there is insufficient statistical power to distinguish between completely different alternatives concerning individual optima of males. Copyright 1998 The Association for the Study of Animal Behaviour
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Affiliation(s)
- H Kokko
- Department of Ecology and Systematics, University of Helsinki
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Quinn GE, Dobson V, Kivlin J, Kaufman LM, Repka MX, Reynolds JD, Gordon RA, Hardy RJ, Tung B, Stone RA. Prevalence of myopia between 3 months and 5 1/2 years in preterm infants with and without retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity Cooperative Group. Ophthalmology 1998; 105:1292-300. [PMID: 9663236 DOI: 10.1016/s0161-6420(98)97036-1] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
PURPOSE The purpose of the study was to examine spherical equivalent refractive errors, especially myopia, at six ages between 3 months and 5 1/2 years post-term in preterm children with birth weights of less than 1251 g. DESIGN A cohort study. PARTICIPANTS There were a total of 827 participants in the multicenter study of cryotherapy for retinopathy of prematurity (ROP). Approximately one third of the eyes did not develop ROP, whereas two thirds developed mild-to-severe ROP. None of the eyes underwent cryotherapy. INTERVENTION Refractive error was measured at 3 months, 1 year, and 5 1/2 years term due date at the five long-term follow-up centers. In most eyes, refractive error also was measured at 2, 3 1/2, and 4 1/2 years. MAIN OUTCOME MEASURE Myopia was defined as 0.25 diopter (D) or greater with high myopia as 5 D or greater. RESULTS The proportion of eyes with myopia in this preterm population was increased compared to published data on full-term children and was related to severity of both acute-phase and cicatricial-phase ROP. The percentage of eyes with myopia varied little across ages, ranging from 21.2% at 1 year to 15.7% at 4 1/2 years. The percentage of eyes with high myopia doubled from 1.8% to 3.9% between 3 months and 1 year and remained stable thereafter. The distribution of refractive errors in eyes with mild acute-phase ROP was similar to that of eyes with no ROP. In contrast, eyes with moderate or severe acute-phase ROP showed an increased prevalence of high myopia. The distribution of refractive errors changed between 3 months and 1 year with little change after 1 year. This pattern of refractive development differs from that of full-term infants. Birth weight, severity of ROP, and degree of myopia at 3 months predicted the presence of myopia and high myopia at 5 1/2 years of age. CONCLUSIONS The distribution of refractive errors in preterm infants from age 3 months to 5 1/2 years varies with severity of acute-phase ROP and cicatricial disease. Changes in refractive error distribution occur primarily between 3 months and 1 year and involve a decrease in the proportion of eyes with hyperopia and an increase in the proportion with high degrees of myopia.
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Affiliation(s)
- G E Quinn
- Division of Pediatric Ophthalmology, Children's Hospital of Philadelphia, PA 19104, USA
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Abstract
A 24-year-old woman at 37 weeks gestation, with an uncorrected atrioventricular canal defect and incipient congestive heart failure is presented. This rare defect is part of the larger group of endocardial cushion defects. The peripartum anesthetic management of this condition has not been described. Our patient had a large atrial septal defect, a common regurgitant atrioventricular valve, a large left-to-right shunt and a small ventricular septal defect. Her pregnancy was maintained until she developed symptoms of congestive heart failure. We discuss her peripartum management, monitoring and anesthetic choices.
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Affiliation(s)
- R J Goldsmith
- Department of Anesthesia, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
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Abstract
BACKGROUND Infection after strabismus surgery is uncommon and its cause remains unanswered. The source of the bacteria and the manner in which it enters the eye is often unknown. Most pediatric ophthalmologists now use 5% povidone-iodine to reduce the bacterial population before surgery. The needles used during strabismus surgery may be a source of bacterial contamination. METHODS One hundred six needles were cultured after their use in strabismus surgery. RESULTS Sixteen of 106 needles (15.1%) and 15 of 61 cases (24.6%) were culture positive. The organisms recovered closely resembled indigenous bacterial flora. CONCLUSION This study suggests that the needles used during strabismus surgery may be the source of bacteria that can lead to infections after strabismus surgery.
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Affiliation(s)
- S E Olitsky
- Department of Ophthalmology, Children's Hospital of Buffalo, New York 14222, USA
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Reynolds JD, Hardy RJ, Kennedy KA, Spencer R, van Heuven WA, Fielder AR. Lack of efficacy of light reduction in preventing retinopathy of prematurity. Light Reduction in Retinopathy of Prematurity (LIGHT-ROP) Cooperative Group. N Engl J Med 1998; 338:1572-6. [PMID: 9603794 DOI: 10.1056/nejm199805283382202] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Hospital-nursery lighting has been suggested as a factor in causing retinopathy of prematurity. Despite ongoing debate, a causal relation has not been established. METHODS We conducted a prospective, randomized, multicenter study of the effects of light reduction on 409 premature infants with birth weights of less than 1251 g and gestational ages of less than 31 weeks. Two hundred five infants were exposed to reduced light, and 204 to typical nursery lighting. The amount of light reaching the infants' eyes was reduced within 24 hours after birth by placing goggles on the infants that reduced visible-light exposure by 97 percent and ultraviolet-light exposure by 100 percent. The babies wore the goggles until 31 weeks' postconceptional age or 4 weeks after birth, whichever was longer. Once the goggles were removed, ophthalmologists masked to the treatment assignments assessed the infants for retinopathy of prematurity at least biweekly for up to 13 weeks. RESULTS There were 188 infants in the group that wore goggles and 173 in the control group who survived and were available for follow-up. The mean birth weights were 906 g in the goggles group and 914 g in the control group; the mean gestational ages were 27.4 weeks and 27.2 weeks, respectively. The mean ambient-light level adjacent to the infants' faces was 399 lux for the goggles group and 447 lux for the control group. Retinopathy of prematurity was diagnosed in 102 infants (54 percent) in the goggles group and 100 (58 percent) in the control group (relative risk, 0.9; 95 percent confidence interval, 0.8 to 1.1; P=0.50). CONCLUSIONS A reduction in ambient-light exposure does not alter the incidence of retinopathy of prematurity.
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Reynolds JD, Zeballos GA, Penning DH, Kimura KA, Atkins B, Brien JF. Nitrate and nitrite anion concentration in the intact cerebral cortex of preterm and nearterm fetal sheep: indirect index of in vivo nitric oxide formation. J Pharmacol Toxicol Methods 1998; 39:125-8. [PMID: 9741385 DOI: 10.1016/s1056-8719(98)00007-0] [Citation(s) in RCA: 5] [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: 02/08/2023]
Abstract
Pregnant sheep with a microdialysis probe implanted in the fetal cerebral cortex were used to determine if nitrate and nitrite anions (nitrate/nitrite) could be quantitated in the microdialysate as an indirect index of in vivo nitric oxide formation. Pregnant ewes (term, about 147 days) were surgically instrumented at gestational day (GD) 90 (n = 3; preterm) and GD 121 (n = 3; nearterm). Three days later, following an overnight probe equilibration period, five dialysate samples were collected continuously on ice at 1-h intervals (infusion rate of 1 (microl/min). The nitrate/nitrite concentration was determined by reducing a 10-microl aliquot of each dialysate fraction with hot acidic vanadium followed by chemiluminescence quantitation of the nitric oxide product. The lower limit of quantitative sensitivity of the method is 25 picomoles. Nitrate/nitrite concentration was 16.6+/-7.3 microM for the preterm fetus and 19.7+/-1.9 microM for the nearterm fetus. The data demonstrate that nitrate/nitrite, as an index of in vivo nitric oxide formation, can be quantitated in microdialysate samples collected from the intact fetal sheep cerebral cortex.
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Affiliation(s)
- J D Reynolds
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Henderson JL, Reynolds JD, Dexter F, Atkins B, Hrdy J, Poduska D, Penning DH. Chronic hypoxemia causes extracellular glutamate concentration to increase in the cerebral cortex of the near-term fetal sheep. Brain Res Dev Brain Res 1998; 105:287-93. [PMID: 9541746 DOI: 10.1016/s0165-3806(97)00192-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fetal hypoxia is an important cause of neurologic morbidity and mortality. Hypoxia-induced increase in extracellular glutamate concentration can lead to excitotoxic neuronal death in adults. The objective of this study was to test whether chronic fetal hypoxemia increases extracellular glutamate concentration in the unanesthetized intact cerebral cortex of the near-term fetal sheep. Microdialysis probes were implanted into the parasagittal parietal cortex and periventricular white matter of near-term fetal sheep. At 124 +/- 1 days of gestation, extracellular glutamate concentration was determined before and during 24 h of fetal hypoxemia. Chronic hypoxemia was produced by tightening a vascular occluder placed around the maternal common iliac artery. Larger decreases in fetal arterial oxygen content were associated with larger increases in extracellular glutamate concentration in the parietal cortex (Kendall's tau = 0.81, N = 7, p = 0.005). No such relationship was detected in the periventricular white matter. Chronic hypoxemia increases extracellular glutamate concentration in the intact cerebral cortex of the unanesthetized near-term fetal sheep.
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Affiliation(s)
- J L Henderson
- Department of Obstetrics and Gynecology, University of Iowa, College of Medicine, Iowa City, USA
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