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Yankovich TL, Roberts M, Brown J, Mori Y, Williams GA, Charalambous F, Pepin S. Practical application of international recommendations and safety standards in the systematic planning and implementation of remediation of sites or areas with residual radioactive material. J Radiol Prot 2022; 42:020513. [PMID: 35551120 DOI: 10.1088/1361-6498/ac6a87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
The IAEA fundamental safety objective is'to protect people and the environment from harmful effects of ionizing radiation'and this must be done 'without unduly limiting the operation of facilities or the conduct of activities that give rise to radiation risks', while ensuring that people and the environment, present and future are protected against radiation risks (IAEA 2006Fundamental Safety Principles, Safety FundamentalsNo. SF-1). In addition,'protective actions to reduce existing or unregulated radiation risks must be justified and optimized'(IAEA 2006Fundamental Safety Principles, Safety FundamentalsNo. SF-1). An international system of radiological protection can be applied such that processes, such as remediation, can be systematically undertaken to address the wide range of'existing exposure situations'present globally. In doing so, decisions made regarding actions undertaken can be demonstrated to be'justified'and'optimized'(i.e. balanced), such that the amount of effort should be commensurate with the risk (applying a'graded approach'). In addition, protection of people and the environment can be demonstrated by comparing the actual exposure to appropriate criteria over the lifetime of remediation. This paper provides an overview of the current IAEA safety standards on remediation of sites or areas contaminated with residual radioactive material within the international system of radiological protection and provides practical examples of their application through case studies considered in IAEA international model validation programs.
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Affiliation(s)
- T L Yankovich
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria
| | - M Roberts
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria
| | - J Brown
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria
| | - Y Mori
- International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, Austria
| | - G A Williams
- Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - F Charalambous
- Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - S Pepin
- Federal Agency for Nuclear Control, Brussels, Belgium
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Hui TY, Crickenberger S, Lau JWT, Williams GA. Why are "suboptimal" temperatures preferred in a tropical intertidal ectotherm? J Anim Ecol 2022; 91:1400-1415. [PMID: 35302242 DOI: 10.1111/1365-2656.13690] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/07/2022] [Indexed: 11/28/2022]
Abstract
In thermally extreme environments it is challenging for organisms to maximize performance due to risks associated with stochastic variation in temperature and, subsequently, over evolutionary time minimizing the exposure to risk can serve as one of the mechanisms that result in organisms preferring suboptimal temperatures. We tested this hypothesis in a slow-moving intertidal snail on tropical rocky shores, where temperature variability increases with time from 30 min to 20 h when recorded at 30 min intervals (due to short-term environmental autocorrelation where temperatures closer in time are more similar as compared to temperatures over a long period of time). Failure to accommodate temporal variation in thermal stress by selecting cool habitats can result in mortality. Thermal performance curves for different traits (heart rate and locomotion) were measured and compared to the snail's thermal preferences in both the field and laboratory. Predicted performances of the snails were simulated based on thermal performance curves for different traits over multiple time scales and simulated carryover effects. A strong mismatch was found between physiological and behavioural thermal maxima of the snails (physiological thermal maximum being higher by ~ 7 °C), but the snails avoided these maxima and sought temperatures 7 - 14 °C cooler. Such a risk-averse strategy can be explained by their predicted performances where the snails should make decisions about preferred temperatures based on time periods ≥ 5 h to avoid underestimating the temporal variation in body temperature. In extreme and stochastic environments, where the temporal variation in environmental conditions can lead to substantial divergence between instantaneous and time-averaged thermal performances, "cooler is better" and "suboptimal" body temperatures are preferred as they provide sufficient buffer to reduce mortality risk from heat stress.
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Affiliation(s)
- T Y Hui
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - S Crickenberger
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - J W T Lau
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, China
| | - G A Williams
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, China
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Oso AO, Lala OA, Oke EO, Williams GA, Taiwo AG, Ogunsola ZO. Effects of dietary supplementation with vitamin E, selenium yeast or both on egg incubation response, embryonic development, keet quality, and posthatch growth of helmeted guinea fowl breeders. Trop Anim Health Prod 2020; 52:2667-2675. [PMID: 32474755 DOI: 10.1007/s11250-020-02294-7] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 05/13/2020] [Indexed: 11/30/2022]
Abstract
This study investigated the effects of dietary supplementation with vitamin E (vit. E), selenium yeast (Se yeast), or both on egg incubation response, embryonic development, keet quality, and posthatch growth of helmeted guinea fowls. Two hundred and forty 24-week old helmeted guinea fowl hens (average weight 1.75 + 0.22 kg) and cocks (average weight 2.15 + 0.20 kg) were assigned into 24 pens; each pen housed 10 hens and 2 cocks. There were four dietary treatments consisting of a basal diet (control), basal diet supplemented with vit. E (30 IU/kg), Se yeast (0.3 mg/kg Se), or both. Six pens were assigned to each treatment. Egg incubation response were estimated using 504 settable eggs sampled from each treatment collected during 15 to 17 weeks in lay. A total of 72 fertile eggs sampled from each treatment were used for the estimation of embryonic development. Quality of day-old keets hatched was scored based on physical conditions, while posthatch growth was measured for 21 days. Guinea fowl breeders fed diet supplemented with both vit. E and Se yeast produced the highest (P < 0.05) number of fertile eggs, percentage fertility, number of hatchlings, hatchability of total eggs, and hatchability of fertile eggs. Supplementation with vit. E + Se yeast resulted in the heaviest (P < 0.05) embryo weight, relative embryo weight, least (P < 0.05) yolk sac weight, and relative yolk sac weight on 25 days of incubation. Hatchlings from breeders fed diet supplemented with Se yeast and vit. E + Se yeast showed normal swallowed yolk. Supplementation of maternal diet with vit. E, Se yeast, and vit. E + Se yeast resulted in improved (P < 0.05) feed conversion ratio of subsequent hatchlings during 1 to 7-day posthatch growth. It can be concluded that dietary supplementation of vit. E + Se yeast in guinea fowl breeders resulted in improved egg fertility, hatchability, heavier embryo weights, hatchlings of good quality, and improved posthatch growth during the first 7 days.
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Affiliation(s)
- A O Oso
- Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, PMB 2240, Nigeria.
| | - O A Lala
- Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, PMB 2240, Nigeria
| | - E O Oke
- Department of Animal Physiology, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, PMB 2240, Nigeria
| | - G A Williams
- Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, PMB 2240, Nigeria
| | - A G Taiwo
- Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, PMB 2240, Nigeria
| | - Z O Ogunsola
- Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, PMB 2240, Nigeria
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Crickenberger S, Hui TY, Landry Yuan F, Bonebrake TC, Williams GA. Preferred temperature of intertidal ectotherms: Broad patterns and methodological approaches. J Therm Biol 2019; 87:102468. [PMID: 32001017 DOI: 10.1016/j.jtherbio.2019.102468] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 10/29/2019] [Accepted: 11/23/2019] [Indexed: 12/30/2022]
Abstract
Preferred temperature (Tpref) has been measured in over 100 species of aquatic and 300 species of terrestrial ectotherms as a metric for assessing behavioural thermoregulation in variable environments and, as such, has been linked to ecological processes ranging from individual behaviour to population and community dynamics. Due to the asymmetric shape of performance curves, Tpref is typically lower than the optimal temperature (Topt, where physiological performance is at its peak), and the degree of this mismatch increases with variability in Tb. Intertidal ectotherms experience huge variability in Tb on a daily basis and therefore provide a good system to test whether the relationship between Tpref and variation in Tb holds in more extreme environments. A review of the literature, however, only revealed comparisons between Tpref and Topt for five intertidal species and measurements of Tpref for 23 species. An analysis of this limited literature for intertidal ectotherms showed a positive relationship between acclimation temperature and Tpref. There was, however, great variation in the methodologies employed to make these assessments. Factors contributing to behavioural thermoregulation in intertidal ectotherms including small body size; low mobility; interactions among individuals; endogenous clocks; metabolic effects; thermal sensitivity; sampling of the thermal environment and recent acclimation history were considered to varying degrees when measuring Tpref, confounding comparisons between species. The methodologies used to measure Tpref in intertidal ectotherms were reviewed in light of each of these factors, and methodologies proposed to standardize approaches. Given the theoretical predictions about the relationships between Tpref and variability in Tb, the spatial and temporal thermal variability experienced by intertidal ectotherms provides numerous opportunities to test these expectations if assessed in a standardized manner, and can potentially provide insights into the value of behavioural thermoregulation in the more thermally variable environments predicted to occur in the near future.
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Affiliation(s)
- S Crickenberger
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
| | - T Y Hui
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - F Landry Yuan
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - T C Bonebrake
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - G A Williams
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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Williams GA, O'Brien RS, Grzechnik M, Wise KN. ESTIMATES OF RADIATION DOSES TO THE SKIN FOR PEOPLE CAMPED AT WALLATINNA DURING THE UK TOTEM 1 ATOMIC WEAPONS TEST. Radiat Prot Dosimetry 2017; 174:322-336. [PMID: 27881792 DOI: 10.1093/rpd/ncw192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 06/22/2016] [Indexed: 06/06/2023]
Abstract
A group of Aboriginal people was camped at Wallatinna in South Australia, ~170 km downwind from Emu Field, where an atomic test (the Totem 1 test) was carried out at 07.00 on 15 October 1953 local time (21.30 on 14 October 1953 GMT (Greenwich Mean Time)). They left the camp ~24 hours later. These people stated that a phenomenon that has become known as a 'black mist' rolled through their camp site ~5 hours after detonation and that some of them subsequently became sick, displaying skin reddening and nausea. They feared that the sickness was a result of exposure to high levels of radiation. The purpose of this paper is to determine if these people could have received ionising radiation doses high enough to cause the symptoms displayed. The methodology used for the dose estimates is described in the paper. The exposure modes considered were external exposure due to the passage of a contaminated plume over the camp site, inhalation of material from this plume, external exposure from material deposited on the ground as the plume passed, and consumption of contaminated food and water. The contaminants considered in the airborne cloud and the ground plume were fission products and unburnt plutonium from the nuclear detonation, and neutron activation products caused by vaporisation of the tower used to position the weapon. The source was approximated by a line source. An upper estimate of the effective doses received is ~4 mSv, which is well below the level at which acute radiation effects are observed. This estimate is consistent with earlier assessments, which did not consider inhalation of the contribution from neutron activation products.
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Affiliation(s)
- G A Williams
- ARPANSA, 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - R S O'Brien
- ARPANSA, 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - M Grzechnik
- ARPANSA, 619 Lower Plenty Road, Yallambie, VIC 3085, Australia
| | - K N Wise
- 11 Kinnear Court, Montmorency, VIC 3094, Australia
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Serena M, Williams GA, Weeks AR, Griffiths J. Variation in platypus (Ornithorhynchus anatinus) life-history attributes and population trajectories in urban streams. AUST J ZOOL 2014. [DOI: 10.1071/zo13079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An understanding of animal population dynamics relies on identifying life-history attributes associated with population growth and determining how these are affected by environmental variables. We analysed platypus population processes over a 10-year period through mark–recapture studies conducted in three spatially independent stream systems located in the suburbs of Melbourne, Australia. The three populations were collectively characterised by a slightly male-biased adult sex ratio (1.15 : 1) and relatively low reproductive success (<0.5 juvenile captured annually per adult female). An estimated 16% of core residents disappeared annually and 18% of marked juveniles were recaptured as adults. However, some demographic parameters (reproductive success, frequency of non-core adult captures) varied significantly among populations. Estimates of annual core population size in the three systems varied asynchronously, with different trajectories in population size potentially reflecting habitat differences (amount of urban development, reliability of surface flow) as well as variation in spatial isolation and catchment history (implementation of stream rehabilitation programs, occurrence of severe floods). Across all three populations, significant variability in annual reproductive success was explained by linear relationships with the amount of rainfall recorded in the five months before breeding (positive) and after juveniles emerge from nesting burrows (negative).
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Williams GA, Serena M, Grant TR. Age-related change in spurs and spur sheaths of the platypus (Ornithorhynchus anatinus). Aust Mammalogy 2013. [DOI: 10.1071/am12011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Non-invasive techniques for age assessment of wild mammals are needed for effective species management as well as research. In the case of the platypus, we investigated how morphology of calcaneal spurs and associated features in males and vestigial spur sheaths in females varies with age. Total spur length in males (spur tip to base of subtending epidermal collar) is greatest at 19–24 months and falls thereafter, with significant linear relationships evident between spur length and age of subadults (13–24 months old) and adults (≥25 months old). However, collar length/total spur length discriminates better between subadults and older animals than either collar length or total spur length alone. Juveniles can be reliably identified up to the age of 12 months (males) and 9 months (females) by the presence, respectively, of a sheath encasing the spur or a rudimentary spur sheath. A small proportion of young subadults (males, 4%; females, ≤2%) will be misclassified as juveniles due to sheaths being retained for longer than normal. Studies that need to identify juveniles very accurately as an age class should avoid sampling populations from August–October on the south-eastern Australian mainland (or May–October if subadult males also need to be identified correctly).
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Serena M, Williams GA. Movements and cumulative range size of the platypus (Ornithorhynchus anatinus) inferred from mark–recapture studies. AUST J ZOOL 2012. [DOI: 10.1071/zo12121] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The extent of mammalian movements often varies with size, sex and/or reproductive status. Fyke nets were set along streams and rivers near Melbourne (southern Victoria) from the mid-1990s to 2007, and in the Wimmera River catchment (western Victoria) from 1997 to 2005, to assess how far platypus of different age and sex classes travelled between captures and over longer periods. The mean distance between consecutive captures of adults did not vary significantly as intervals increased from 1–3 months to >3 years, suggesting that most individuals occupied stable ranges. However, adult females travelled, on average, only 35% as far between captures as males in southern Victoria, and 29% as far in the Wimmera. Up to half of this difference may be explained by variation in size-related metabolic requirements. Immature males and females respectively moved 61% and 53% as far, on average, as their adult equivalents, although two young males dispersed >40 km. Adults incrementally occupied up to 13.9 km of channel in the case of a male (based on six captures over 67 months) and 4.4 km of channel in the case of a female (based on five captures over 127 months).
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D’Angelo GJ, Glasser A, Wendt M, Williams GA, Osborn DA, Gallagher GR, Warren RJ, Miller KV, Pardue MT. Visual specialization of an herbivore prey species, the white-tailed deer. CAN J ZOOL 2008. [DOI: 10.1139/z08-050] [Citation(s) in RCA: 19] [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
To gain knowledge of visual specializations influencing the behavior of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)), we examined gross eye characteristics, structural organization of the retina, and the density and distribution of cone photoreceptors. White-tailed deer possess ocular features similar to other ungulates including a horizontal slit pupil, reflective tapetum lucidum, typical retinal structure, and medium wavelength sensitive cone photoreceptors concentrated in a horizontal visual streak. The tapetum was found to cover the superior portion of the eye and overlapped the horizontal visual streak. Comparisons between fawns and adults did not reveal any differences in retinal thickness, retinal nuclei counts, or cone photoreceptor counts. While M-cones had increased density in the visual streak, S-cones were distributed evenly across the entire retina. Schematic eye calculations of a 0.5-year-old deer indicated a hyperopic eye (+7.96) with a F/# ranging from 5.55 to 1.39 for pupil diameters of 3 to 12 mm. As expected for a crepuscularly active prey species, the visual system of white-tailed deer is specialized for sensitivity in low-light conditions and detection of predators.
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Affiliation(s)
- G. J. D’Angelo
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - A. Glasser
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - M. Wendt
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - G. A. Williams
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - D. A. Osborn
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - G. R. Gallagher
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - R. J. Warren
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - K. V. Miller
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
| | - M. T. Pardue
- Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
- School of Optometry, University of Houston, Houston, TX 77204, USA
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA
- Department of Animal Sciences, Berry College, Mount Berry, GA 30149, USA
- Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30033, USA
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Williams GA, Ott TL, Michal JJ, Gaskins CT, Wright RW, Daniels TF, Jiang Z. BRIEF NOTES: Development of a model for mapping cryptorchidism in sheep and initial evidence for association of INSL3 with the defect. Anim Genet 2007; 38:189-91. [PMID: 17355391 DOI: 10.1111/j.1365-2052.2007.01585.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G A Williams
- Department of Animal Sciences, Washington State University, Pullman, WA 99164-6351, USA
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Abstract
Macular hole size is a predictor for anatomical closure. Holes >400 μm in aperture size on an OCT scan are more likely to close when ILM is peeled
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Hermel M, Mahgoub M, Youssef T, Azrak MI, Raza H, Alldredge C, Trese M, Williams GA, Hartzer M. Safety profile of the intravitreal streptokinase-plasmin complex as an adjunct to vitrectomy in the rabbit. Graefes Arch Clin Exp Ophthalmol 2005; 244:996-1002. [PMID: 16365737 DOI: 10.1007/s00417-005-0159-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2005] [Revised: 08/30/2005] [Accepted: 09/19/2005] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The generation of an atraumatic posterior vitreous detachment (PVD), a common goal in vitreoretinal surgery, is a challenge, particularly in children and young trauma patients. Plasmin has been proposed as an adjunct to vitrectomy to enzymatically generate a PVD. Low doses of streptokinase-activated plasmin were tested in human pilot studies. This dose-escalation study assesses the safety range of intravitreal human streptokinase-plasmin in rabbits. METHODS Plasminogen was isolated from human plasma by affinity chromatography, followed by activation with streptokinase (1:1), to generate the streptokinase-plasmin complex. Enzyme doses from 0.1-7 activity units (AU, in 0.1 ml) were injected into the mid-vitreous of 35 eyes; six control eyes were injected with balanced salt solution (BSS, 0.1 ml). Thirty minutes after injection, a two-port vitrectomy was performed. Fundus and slit lamp examinations were performed on days 1 and 7. On days 2 and 7, bright flash electroretinography was performed and compared with preoperative recordings. Some animals receiving higher doses of streptokinase-plasmin (1-7 AU) were followed clinically and with electroretinography for up to 9 months. RESULTS A mild-to-moderate inflammatory response was seen in both control and plasmin-treated eyes on day 1, but had disappeared completely by day 7 in most eyes. In the 7 AU group, inflammation was stronger and more protracted. Two of three eyes from this group developed wrinkling of the medullary rays; one of them showed discoloration and traction at the medullary rays in the late follow-up. Electroretinograms (ERGs) of vitrectomized control eyes showed the following changes from preoperative values: 48 h, a-wave -11.10% [no significant (n.s.)], b-wave -14.62% (P=0.046); 7 days, a-wave +9.18% (n.s.), b wave +11.69% (n.s.). For the enzyme-treated eyes: 48 h: a-wave -20.43% (P<0.001), b-wave -9.57% (p<0.001); 7 days: a wave -14.21% (P<0.001), b-wave +2.48% (P<0.001). There was no evidence of dose-dependent ERG changes in enzyme-treated eyes at doses up to 5 AU. Groups of up to 3 AU were investigated by light and transmission electron microscopy, without evidence of toxicity. CONCLUSION Streptokinase-plasmin doses up to 3 AU were found to be safe when injected into rabbit eyes followed by vitrectomy.
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Affiliation(s)
- M Hermel
- Department of Ophthalmology, RWTH Aachen University, Pauwelsstrasse 30, 52057, Aachen, Germany.
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Pal B, Mohamed MD, Keen TJ, Williams GA, Bradbury JA, Sheridan E, Inglehearn CF. A new phenotype of recessively inherited foveal hypoplasia and anterior segment dysgenesis maps to a locus on chromosome 16q23.2-24.2. J Med Genet 2005; 41:772-7. [PMID: 15466012 PMCID: PMC1735603 DOI: 10.1136/jmg.2004.020040] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Farah ME, Cardillo JA, Luzardo AC, Calucci D, Williams GA, Costa RA. Indocyanine green mediated photothrombosis for the management of predominantly classic choroidal neovascularisation caused by age related macular degeneration. Br J Ophthalmol 2004; 88:1055-9. [PMID: 15258024 PMCID: PMC1772261 DOI: 10.1136/bjo.2003.035808] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2003] [Indexed: 11/03/2022]
Abstract
AIMS To study the effectiveness of indocyanine green mediated photothrombosis in the management of predominantly classic subfoveal choroidal neovascularisation associated with age related macular degeneration. METHODS Prospective, non-comparative, interventional case series of nine patients with predominantly classic subfoveal choroidal neovascularisation secondary to age related macular degeneration who declined photocoagulation or verteporfin photodynamic therapy. Patients were submitted to one or more treatments with an intravenous injection of a small volume of high concentration indocyanine green solution followed by low irradiance, large spot 810 nm continuous laser application via a transpupillary approach. Main outcome measures were change in best corrected visual acuity and macular exudative manifestations. RESULTS After 12 months of follow up, the final best corrected visual acuity was the same (plus or minus two ETDRS lines) in five eyes (55%), improved more than two ETDRS lines in three eyes (33%), and worsened by more than two lines in the remaining eye. The improved vision was probably related to partial or complete restoration of the macular architecture as a result of fluid resolution, whereas the worsened vision was primarily the result of treatment failure in achieving substantial choroidal neovascular occlusion. There were no complications related to the procedure. CONCLUSION Indocyanine green mediated photothrombosis may be an effective alternative treatment for predominantly classic subfoveal choroidal neovascularisation caused by age related macular degeneration.
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Affiliation(s)
- M E Farah
- Department of Ophthalmology, Instituto da Visão-IPEPO, Federal University of São Paulo, School of Medicine, Brazil.
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Chelazzi G, De Pirro M, Williams GA. Different cardiac response to copper in limpets from metal polluted and clean shores of Hong Kong. Mar Environ Res 2004; 58:83-93. [PMID: 15046947 DOI: 10.1016/j.marenvres.2004.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 01/03/2004] [Indexed: 05/24/2023]
Abstract
The gastropod limpet, Cellana grata, is common on moderately exposed to exposed Hong Kong rocky shores. On the basis of the existing literature on trace metal contamination in Hong Kong, four sites were identified, representative of highly polluted (Aberdeen and Lei Yue Mun) and clean (Cape d'Aguilar and Clear Water Bay) conditions. Limpets from the two polluted sites showed similar, but significantly higher body concentrations of copper than limpets from the two clean sites, which were also similar. Non-invasive measurements of cardiac activity of limpets from the four sites showed between site differences in baseline heart rates under standard seawater, irrespective of pollution level. When acutely exposed to water borne copper (2 h, 0.5+/-0.06 SD ppm), however, limpets from clean sites showed a significantly higher increase in inter-beating time (bradycardia) than those from polluted sites. These results highlight the potential use of cardiac activity to assess the exposure of natural populations of limpets to trace metal pollution.
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Affiliation(s)
- G Chelazzi
- Dipartimento di Biologia Animale e Genetica, Università degli Studi di Firenze, Via Romana 17, 50125 Firenze, Italy
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Whitaker J, Ahn E, Hari P, Williams GA, Taylor PC, Facelli JC. Indirect (J) coupling of inequivalent 75As nuclei in crystalline and glassy As2Se3 and As2S3. J Chem Phys 2003. [DOI: 10.1063/1.1612920] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jacobs GH, Calderone JB, Fenwick JA, Krogh K, Williams GA. Visual adaptations in a diurnal rodent, Octodon degus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2003; 189:347-61. [PMID: 12679876 DOI: 10.1007/s00359-003-0408-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [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: 12/19/2002] [Revised: 02/18/2003] [Accepted: 03/05/2003] [Indexed: 10/25/2022]
Abstract
The degu (Octodon degus) is a diurnal rodent, native to Chile. Basic features of vision and visual organization in this species were examined in a series of anatomical, electrophysiological and behavioral experiments. The lens of the degu eye selectively absorbs short-wavelength light and shows a progressive increase in optical density as a function of age. Electroretinograms recorded using a flicker-photometric procedure reveal three spectral mechanisms: a rod with peak sensitivity of about 500 nm and two types of cone having respective spectral peaks of about 362 nm and 507 nm. Opsin antibody labeling was used to determine the retinal distributions of the three receptor types. A total of about one-third of the approximately 9 million photoreceptors of the degu retina are cones with the two types (507 nm/362 nm) represented in a ratio of about 13:1. The contributions to vision of all three receptor types were examined in a series of behavioral experiments. A consistent feature of both the electrophysiological and behavioral results is that relatively high levels of light adaptation are required to effect the full transition from rod-based to cone-based vision. In behavioral tests degus were shown to be able to make color discriminations between ultraviolet and visible lights.
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Affiliation(s)
- G H Jacobs
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
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Hoskins BF, Robson R, Williams GA, Wilson JC. Oxidation of an o-aminophenol-derived Schiff-base component of a binucleating ligand to a benzoxazole and the crystal structures of a mononuclear palladium derivative and a tetranuclear [palladium-silver] Pd2Ag2 derivative with an unusually short silver-silver distance. Inorg Chem 2002. [DOI: 10.1021/ic00022a015] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Williams GA, Ferguson JB. THE SOLUBILITY OF HELIUM AND HYDROGEN IN HEATED SILICA GLASS AND THE RELATION OF THIS TO THE PERMEABILITY1. J Am Chem Soc 2002. [DOI: 10.1021/ja01668a012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gutowsky HS, Holm CH, Saika A, Williams GA. Electron Coupling of Nuclear Spins. I. Proton and Fluorine Magnetic Resonance Spectra of Some Substituted Benzenes1,2. J Am Chem Soc 2002. [DOI: 10.1021/ja01574a007] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abrahams BF, Hardie MJ, Hoskins BF, Robson R, Williams GA. Topological rearrangement within a single crystal from a honeycomb cadmium cyanide [Cd(CN)2]n 3D net to a diamond net. J Am Chem Soc 2002. [DOI: 10.1021/ja00052a073] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Finding optimal three-dimensional molecular configurations based on a limited amount of experimental and/or theoretical data requires efficient nonlinear optimization algorithms. Optimization methods must be able to find atomic configurations that are close to the absolute, or global, minimum error and also satisfy known physical constraints such as minimum separation distances between atoms (based on van der Waals interactions). The most difficult obstacles in these types of problems are that 1) using a limited amount of input data leads to many possible local optima and 2) introducing physical constraints, such as minimum separation distances, helps to limit the search space but often makes convergence to a global minimum more difficult. We introduce a constrained global optimization algorithm that is robust and efficient in yielding near-optimal three-dimensional configurations that are guaranteed to satisfy known separation constraints. The algorithm uses an atom-based approach that reduces the dimensionality and allows for tractable enforcement of constraints while maintaining good global convergence properties. We evaluate the new optimization algorithm using synthetic data from the yeast phenylalanine tRNA and several proteins, all with known crystal structure taken from the Protein Data Bank. We compare the results to commonly applied optimization methods, such as distance geometry, simulated annealing, continuation, and smoothing. We show that compared to other optimization approaches, our algorithm is able combine sparse input data with physical constraints in an efficient manner to yield structures with lower root mean squared deviation.
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Affiliation(s)
- G A Williams
- Stanford Medical Informatics, Stanford University, Stanford, CA, 94305-5479, USA.
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Sarrafizadeh R, Hassan TS, Ruby AJ, Williams GA, Garretson BR, Capone A, Trese MT, Margherio RR. Incidence of retinal detachment and visual outcome in eyes presenting with posterior vitreous separation and dense fundus-obscuring vitreous hemorrhage. Ophthalmology 2001; 108:2273-8. [PMID: 11733270 DOI: 10.1016/s0161-6420(01)00822-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To determine visual outcomes and the incidence of retinal detachment in eyes presenting with posterior vitreous separation and dense fundus-obscuring vitreous hemorrhage. DESIGN Retrospective consecutive noncomparative interventional case series. PARTICIPANTS Thirty-six eyes (15 right eyes and 21 left eyes) of 34 patients (18 female and 16 male) ranging in age from 42 to 94 years. Mean follow-up was 14 months. METHODS A comparison of the best-corrected initial visual acuities versus final visual acuities after spontaneous resolution of vitreous hemorrhage or surgical intervention. The number of eyes that were found to have retinal tears or that had a rhegmatogenous retinal detachment develop was documented. Logarithm of the minimum angle of resolution-converted visual acuities was used for comparison. Categorical data were analyzed by Fisher's exact test, and population means were compared by Student's t test. MAIN OUTCOME MEASURES Final mean visual acuities, number of eyes with at least one retinal tear, location of retinal tears, number of eyes that had retinal detachment develop, and the number of eyes repaired with scleral buckling surgery and/or pars plana vitrectomy. RESULTS Twenty-four of 36 eyes (67%) were found to have at least one retinal break (range, 0-4 breaks), with 88% of breaks located in the superior retina. Eleven eyes (31%) had more than one retinal break. Fourteen of 36 eyes (39%) had a rhegmatogenous retinal detachment develop that was repaired with pars plana vitrectomy and scleral buckling. An additional 14 eyes (39%) underwent vitrectomy for nonclearing vitreous hemorrhage. The incidence of retinal detachment in eyes with a history of retinal detachment in the contralateral eye was 75% (P = 0.04). Seven of 14 eyes (50%) with retinal detachment had coexisting proliferative vitreoretinopathy. Most retinal breaks and detachments occurred in emmetropic or myopic eyes. For all 36 eyes the mean preoperative visual acuity was 20/1233, and the mean final visual acuity was 20/62 (P < 0.0001). Eyes that had a macula-off retinal detachment develop had worse final visual outcomes (20/264; P = 0.01), as did eyes that had proliferative vitreoretinopathy develop (20/129; P = 0.04). CONCLUSIONS Acute, spontaneous, nontraumatic posterior vitreous separation with dense fundus-obscuring vitreous hemorrhage is associated with a high incidence of retinal tears and detachment. Close follow-up with clinical examination and ultrasonography is necessary, because many of these eyes may eventually require surgical intervention. Aggressive management with early vitrectomy should be considered when there is a history of retinal detachment in the contralateral eye.
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Affiliation(s)
- R Sarrafizadeh
- Associated Retinal Consultants, PC, William Beaumont Hospital, 3535 W 13 Mile Road, Suite 632, Royal Oak, MI 48073, USA
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Abstract
PURPOSE To describe acquired ocular toxoplasmosis in deer hunters. METHODS AND RESULTS The authors describe five young men presenting with flu-like symptoms followed by visual loss due to a unilateral, focal necrotizing retinitis. All five men gave a history of ingesting undercooked or uncooked venison. All five had elevated toxoplasma serology, and all five improved clinically with an antitoxoplasma regimen. CONCLUSION In previously healthy young men, flu-like symptoms associated with visual loss and retinitis should prompt questioning about hunting and raw game meat ingestion, especially when toxoplasmosis is suspected.
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Affiliation(s)
- R D Ross
- Retina Vitreous Center, Grand Blanc, Michigan, USA
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Abstract
PURPOSE This is a pilot study to assess the use of autologous plasmin enzyme (APE) as an adjunct to vitreous surgery in eyes with advanced diabetic retinopathy. DESIGN Prospective noncomparative interventional case series. PARTICIPANTS Seven patients with advanced diabetic retinopathy selected at random from our practice population. METHODS Seven eyes were treated with APE as an adjunct to standard vitreous surgery. Six eyes had macular tractional retinal detachments, and one eye had refractory macular edema. Three fellow eyes had standard vitreous surgery performed for macular tractional retinal detachments without APE. All 10 eyes had macular edema and background diabetic retinopathy. MAIN OUTCOME MEASURES The main outcome measures included induction of a posterior vitreous detachment, retinal reattachment, improvement in visual acuity, and resolution of macular edema. RESULTS All seven APE-treated eyes achieved spontaneous or easy removal of the posterior hyaloid including one eye that had vitreoschisis over areas of detached retina. All eyes treated with APE had resolution of intraretinal edema. Retinas of all eyes treated with APE were reattached. The three fellow eyes were treated by vitreous surgery without APE. Two of the three fellow eyes had reattached retinas, but none had resolution of intraretinal edema without further focal photocoagulation treatment. Mean visual acuity improvement was 0.7 logarithm of the minimum angle of resolution (LogMAR) units in APE-treated eyes and 0.1 LogMAR units in eyes without APE. The average follow-up period was 14 months. CONCLUSIONS This pilot study suggests that APE may be beneficial in the surgical management of diabetic retinopathy.
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Affiliation(s)
- J G Williams
- William Beaumont Hospital, Royal Oak, Michigan, USA
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Abstract
PURPOSE To describe the results of retinal tears and rhegmatogenous retinal detachments (RD) in adults with retinopathy of prematurity (ROP). DESIGN Noncomparitive interventional case series. METHODS Retrospective cohort of 216 eyes of 108 patients, 15 years or older, followed for up to 23 years (median, 6.2 years). RESULTS One eye was initially seen with an RD, and during follow-up 30 eyes had an RD develop. An additional surgical procedure was required in 7 of the 31 eyes (23%) with an RD. Four eyes were initially seen with retinal tears, and during follow-up 19 eyes had a retinal tear develop. Seven of the 23 eyes (30%) with a retinal tear had initial repair fail. Eyes with minimal cicatricial changes from ROP were still at high risk for tears and detachments developing. Eighty percent of eyes with retinal tears and 60% of eyes with an RD that started with vision >20/60 maintained that level of vision at the final examination. CONCLUSION In patients with a history of premature birth, features of fundus examinations do not correlate with the occurrence of a retinal tear or RD. Repair of a tear or detachment in such a patient is more likely to require multiple procedures but can still be associated with good visual results. Physicians should consider widespread relief of vitreoretinal traction for a tear or detachment in any patient with a history of premature birth.
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Affiliation(s)
- R S Kaiser
- Associated Retinal Consultants, Royal Oak, Michigan 48073, USA
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Pollack AL, McDonald HR, Ai E, Green WR, Halpern LS, Jampol LM, Leahy JM, Johnson RN, Spencer WH, Stern WH, Weinberg DV, Werner JC, Williams GA. Sympathetic ophthalmia associated with pars plana vitrectomy without antecedent penetrating trauma. Retina 2001; 21:146-54. [PMID: 11321141 DOI: 10.1097/00006982-200104000-00008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate, describe, and categorize the clinical presentation, clinical course, histopathology, and response to therapy in patients without a history of penetrating ocular trauma who developed sympathetic ophthalmia following pars plana vitrectomy. METHODS The records of patients without a history of trauma who underwent pars plana vitrectomy and developed sympathetic ophthalmia were retrospectively reviewed. Cases were analyzed with respect to clinical presentation, fluorescein angiographic findings, anatomic and visual outcomes, histopathology, and response to therapy. RESULTS Eight eyes were identified. The median age at presentation was 55 years, with a range of 14 to 62 years. The time from vitrectomy to diagnosis of sympathetic ophthalmia ranged from 2 months to greater than 2 years, with a median of 7 months. Six of eight patients (75%) presented with anterior chamber reaction. All eight patients presented with a vitreous inflammatory response. The optic nerve was inflamed clinically or angiographically in four of eight cases (50%). Small yellow-white sub-retinal pigment epithelial deposits were present in four of eight cases (50%). Two eyes had lesions characterized as multifocal choroiditis. One eye had larger yellow placoid-like lesions. One eye presented with vitritis but no retinal lesions. Subretinal choroidal neovascularization was noted in the inciting eye of one patient. Vision improved in the sympathizing eye with immunosuppressive therapy in five of eight cases (62.5%). CONCLUSIONS Sympathetic ophthalmia can be seen following pars plana vitrectomy in patients without penetrating injuries or a history of trauma. Indeed, it may be seen after successful vitrectomy for retinal detachment. Diverse clinical presentations are possible, and persistent or atypical uveitis following vitrectomy should alert the surgeon to the development of sympathetic ophthalmia.
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Affiliation(s)
- A L Pollack
- Retina Research Fund, St. Mary's Medical Center, San Francisco, CA, USA
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Hiner AN, Hernández-Ruiz J, Williams GA, Arnao MB, García-Cánovas F, Acosta M. Catalase-like oxygen production by horseradish peroxidase must predominantly be an enzyme-catalyzed reaction. Arch Biochem Biophys 2001; 392:295-302. [PMID: 11488605 DOI: 10.1006/abbi.2001.2460] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When hydrogen peroxide (H2O2) was provided as the only substrate for horseradish peroxidase C (HRP-C) the catalase-like emission of oxygen gas was observed. The reaction was favored at neutral compared to acidic pH. Addition of the superoxide radical scavengers tetranitromethane (TNM) or superoxide dismutase (SOD) increased activity. TNM's effect was concentration dependent but SOD's was not, indicating that only some of the superoxide generated was released into solution. Manganous ions (Mn2+) react with superoxide radicals to regenerate H2O2 but not oxygen; when added to the reaction medium oxygen production was reduced but not abolished. The effect was essentially concentration independent, suggesting that most oxygen was produced enzymatically and not by chemical disproportionation of superoxide. The catalase-like activities of some site-directed mutants of HRP-C suggest that active site residues histidine 42 and arginine 38 are influential in determining this activity. A clear correlation also existed between catalase activity and the enzymes' resistance to inactivation by H2O2. Computer simulation of a reaction scheme that included catalase-like activity agreed well with experimental data.
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Affiliation(s)
- A N Hiner
- Departamento de Biología Vegetal, Fisiología Vegetal, Universidad de Murcia, Espinardo, Murcia, E-30100, Spain
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Abstract
SUMMARY
Rats (Rattus norvegicus) have two classes of cone, one containing an ultraviolet (UV)-sensitive photopigment and the other housing a pigment maximally sensitive in the middle (M) wavelengths of the visible spectrum. The manner in which signals from these two cone types contribute to rat vision was investigated through recordings of a gross electrical potential (the electroretinogram, ERG) and behavioral discrimination tests. Spectral sensitivity functions obtained from both types of measurement indicate clear contributions from each of the cone classes, but there is a marked enhancement of the relative sensitivity to UV light in the behavioral index; for instance, under some photopic test conditions, rats are approximately equally sensitive to middle-wavelength and UV lights. In adaptation tests, thresholds for UV and M lights were found to be differentially elevated in the presence of chromatic adapting backgrounds, thus providing the possibility that signals from the two cones could be used by the rat visual system to support color discriminations. Evidence of dichromatic color vision in the rat was subsequently obtained from tests of wavelength discrimination.
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Affiliation(s)
- G H Jacobs
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara 93106, USA.
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Benson WE, Cruickshanks KC, Fong DS, Williams GA, Bloome MA, Frambach DA, Kreiger AE, Murphy RP. Surgical management of macular holes: a report by the American Academy of Ophthalmology. Ophthalmology 2001; 108:1328-35. [PMID: 11425696 DOI: 10.1016/s0161-6420(01)00731-x] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE The document describes macular hole surgery and examines the available evidence to address questions about the efficacy of the procedure for different stages of macular hole, complications during and after surgery, and modifications to the technique. METHODS A literature search conducted for the years 1968 to 2000 retrieved over 400 citations that matched the search criteria. This information was reviewed by panel members and a methodologist, and it was evaluated for the quality of the evidence presented. RESULTS There are three multicenter, controlled, randomized trials that constitute Level I evidence and compare the value of surgery versus observation for macular hole. There are three multicenter, controlled, randomized trials studying the use of adjuvant therapy in macular hole repair. Postoperative vision of 20/40 or better has been reported in 22% to 49% of patients in randomized trials. The risks of surgical complications include retinal detachment (3%), endophthalmitis (<1%), cataract (>75%), and late reopening the hole (2% to 10%). CONCLUSIONS The evidence does not support surgery for patients with stage 1 holes. Level I evidence supports surgery for stage 2 holes to prevent progression to later stages of the disease and further visual loss. Level I evidence shows that surgery improves the vision in a majority of patients with stage 3 and stage 4 holes. There is no strong evidence that adjuvant therapy used at the time of surgery results in improved surgical outcomes. Patient inconvenience, patient preference, and quality of life issues have not been studied.
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Abstract
Given the high rate at which biological data are being collected and made public, it is essential that computational tools be developed that are capable of efficiently accessing and analyzing these data. High-performance distributed computing resources can play a key role in enabling large-scale analyses of biological databases. We use a distributed computing environment, Legion, to enable large-scale computations on the Protein Data Bank (PDB). In particular, we employ the Feature program to scan all protein structures in the PDB in search for unrecognized potential cation binding sites. We evaluate the efficiency of Legion's parallel execution capabilities and analyze the initial biological implications that result from having a site annotation scan of the entire PDB. We discuss four interesting proteins with unannotated, high-scoring candidate cation binding sites.
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Affiliation(s)
- A Waugh
- Stanford Medical Informatics, 251 Campus Drive, MSOB X-215, Stanford, CA 94305-5479, USA.
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Baghdassarian O, Chu HC, Tabbert B, Williams GA. Spectrum of luminescence from laser-created bubbles in water. Phys Rev Lett 2001; 86:4934-4937. [PMID: 11384385 DOI: 10.1103/physrevlett.86.4934] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2001] [Indexed: 05/23/2023]
Abstract
The spectrum of the luminescence emitted at the collapse of single laser-induced bubbles in water is measured for different maximum bubble radii. Bubbles as large as 2 mm show a molecular OH(*) band at 310 nm in the spectrum, which otherwise can be fitted approximately with a blackbody curve at a temperature of 7800 K. This finding provides a connection between the light emission of single bubbles and multibubble sonoluminescence, since in the latter case the same molecular band is observed. Surface instabilities are observed in the larger bubbles, and may be connected with the OH(*) emission.
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Affiliation(s)
- O Baghdassarian
- Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA
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Cohen MH, Hirschfeld S, Flamm Honig S, Ibrahim A, Johnson JR, O'Leary JJ, White RM, Williams GA, Pazdur R. Drug approval summaries: arsenic trioxide, tamoxifen citrate, anastrazole, paclitaxel, bexarotene. Oncologist 2001; 6:4-11. [PMID: 11161223 DOI: 10.1634/theoncologist.6-1-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This report summarizes information on drugs recently approved by the Food and Drug Administration, Office of Drug Evaluation I, Division of Oncology Drug Products. Five applications supporting new claims will be discussed: Trisenox (arsenic trioxide) for induction of remission and consolidation in patients with acute promyelocytic leukemia who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy, and whose disease is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression; Nolvadex (tamoxifen citrate) in women with ductal carcinoma in situ, following breast surgery and radiation, to reduce the risk of invasive breast cancer; Arimidex (anastrazole) for first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer; Taxol (paclitaxel), 175 mg/m(2) by 3 h infusion in combination with cisplatin for first-line treatment of advanced ovarian cancer; and Targretin gel (bexarotene) for the topical treatment of cutaneous lesions in patients with stage IA and IB cutaneous T-cell lymphoma who have not tolerated other therapies or who have refractory or persistent disease. Information provided includes rationale for drug development, study design, efficacy and safety results, and pertinent literature references.
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Affiliation(s)
- M H Cohen
- Division of Oncology Drug Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Rockville, Maryland 20852, USA.
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Rich C, Bernstein DS, Gates S, Heaney RP, Johnston CC, Rosenberg CA, Schnaper HW, Tewksbury RB, Williams GA. Factors involved in an objective study of the efficacy of treatment of osteoporosis. Clin Orthop Relat Res 2001; 45:63-6. [PMID: 5937374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Chu HC, Williams GA. Quenched Kosterlitz-Thouless superfluid transitions. Phys Rev Lett 2001; 86:2585-2588. [PMID: 11289986 DOI: 10.1103/physrevlett.86.2585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2000] [Indexed: 05/23/2023]
Abstract
Rapidly quenched Kosterlitz-Thouless (KT) superfluid transitions are studied by solving the Fokker-Planck equation for the vortex-pair dynamics in conjunction with the KT recursion relations. Power-law decays of the vortex density at long times are found, and the results are in agreement with a scaling proposal made by Minnhagen and co-workers for the dynamical critical exponent. The superfluid density is strongly depressed after a quench, with the subsequent recovery being logarithmically slow for starting temperatures near T(KT). No evidence is found of vortices being "created" in a rapid quench; there is only decay of the existing thermal vortex pairs.
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Affiliation(s)
- H C Chu
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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Horn EP, McDonald HR, Johnson RN, Ai E, Williams GA, Lewis JM, Rubsamen PE, Sternberg P, Bhisitkul RB, Mieler WF. Soccer ball-related retinal injuries: a report of 13 cases. Retina 2001; 20:604-9. [PMID: 11131412 DOI: 10.1097/00006982-200011000-00003] [Citation(s) in RCA: 7] [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: 11/26/2022]
Abstract
PURPOSE To describe the clinical characteristics and management of retinal injuries caused by soccer ball impact as well as the mechanism of injury, prognostic features, risk factors, and possible prevention strategies. METHODS Thirteen cases of soccer ball injuries from retina referral practices were retrospectively reviewed, with attention to the mechanism of associated ocular complications and the anatomic and visual outcomes. RESULTS Soccer ball injuries occurred in both male and female patients (9 male, 4 female) with ages ranging from 8 to 21 years (median 14 years). These patients were observed from 0 to 64 months (median follow-up, 8 months). Four patients had traumatic macular holes, two eyes had retinal detachment associated with retinal dialysis, two had retinal tears associated with hemorrhage, one had a choroidal rupture, and one had only vitreous hemorrhage and Berlin's edema. Although six eyes had some degree of traumatic retinal pigment epitheliopathy, it was the primary diagnosis in only three. Visual acuity at presentation ranged from 20/20 to count fingers, with 7/13 (54%) having 20/200 or worse vision. Seven eyes underwent surgical procedures; the remainder were observed. Final visions ranged from 20/20 to count fingers, with 3/13 (23%) having 20/200 or worse vision. Six eyes (46%) improved by two or more lines by the last follow-up. CONCLUSION Soccer ball-related ocular injuries disproportionately affect young players, are more frequent in females than previously reported, and have more severe visual consequences than previously recognized. Injury prevention strategies to minimize contact between the eye and the soccer ball may reduce the incidence and severity of eye injuries.
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Affiliation(s)
- E P Horn
- Department of Ophthalmology, California Pacific Medical Center, San Francisco, USA
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Chow DR, Garretson BR, Kuczynski B, Williams GA, Margherio R, Cox MS, Trese MT, Hassan T, Ferrone P. External versus internal approach to the removal of metallic intraocular foreign bodies. Retina 2001; 20:364-9. [PMID: 10950413 DOI: 10.1097/00006982-200007000-00007] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To review the management of metallic intraocular foreign bodies (IOFB) at a single institution and to compare the use of internal and external approaches for their removal. SUBJECTS AND METHODS A retrospective review was conducted on 70 eyes from 70 patients who underwent surgical removal of a metallic IOFB with either an internal (vitrectomy followed by forceps or internal magnet use) or external approach (large electromagnet) by seven vitreoretinal surgeons at a single institution between 1973 and 1996. Visual acuity and complications occurring with the two approaches were the main outcome measures studied. RESULTS Overall, patients showed significant improvement in visual acuity following surgical intervention (P < 0.001) despite widely varying surgical techniques. When the authors compared patients treated with an external versus an internal approach they found no statistically significant difference with regard to visual outcome and a trend toward a higher rate of postoperative endophthalmitis in the external approach group. CONCLUSION Surgical removal of metallic IOFB results in significant visual improvement. The external approach to the removal of magnetic metallic IOFB remains a viable treatment option in select cases.
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Affiliation(s)
- D R Chow
- Department of Ophthalmology, McGill University, Montreal, Quebec, Canada
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Affiliation(s)
- R Sarrafizadeh
- Associated Retinal Consultants and William Beaumont Hospital, Royal Oak, Michigan 48073, USA
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Banach MJ, Hassan TS, Cox MS, Margherio RR, Williams GA, Garretson BR, Trese MT. Clinical course and surgical treatment of macular epiretinal membranes in young subjects. Ophthalmology 2001; 108:23-6. [PMID: 11150258 DOI: 10.1016/s0161-6420(00)00473-5] [Citation(s) in RCA: 37] [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] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To examine the surgical and nonsurgical visual outcomes of young subjects with idiopathic macular epiretinal membranes (ERMs). DESIGN Retrospective observational and noncomparative interventional case series. PARTICIPANTS Nineteen consecutive subjects (20 eyes) aged 40 years or less with an idiopathic macular ERM. METHODS Group 1: 10 consecutive eyes were initially seen with visual acuity of 20/50 or better; 7 eyes were observed, and 3 eyes with progressive visual loss to <20/50 underwent vitrectomy and membrane peeling. Group 2: 10 consecutive eyes with presenting visual acuity of 20/60 or worse underwent vitrectomy and membrane peeling. MAIN OUTCOME MEASURES Visual acuity, cataract formation, ERM recurrence, operative complications. RESULTS Group 1: With no surgery, visual acuity remained stable or improved in 5 of 10 eyes (50%), with a mean follow-up of 3.7 years. Three of 10 eyes (30%) had visual loss < or =20/60 develop and underwent vitrectomy. Postoperative visual acuity improved an average of 6 lines with a mean follow-up of 17.6 months. Group 2: After vitrectomy, visual acuity improved 2 or more lines in 7 of 10 eyes (70%), with a mean improvement of 4.4 lines and mean follow-up of 29.2 months. Groups 1 and 2: Three of 13 eyes (23%) that underwent vitrectomy had recurrent ERM formation. CONCLUSIONS Young subjects with idiopathic macular ERMs and a presenting visual acuity of 20/50 or better had a favorable visual outcome with observation. Subjects with an initial vision of 20/60 or worse, or those who had a visual decrease to < or =20/60 had significantly improved visual acuity after vitrectomy. ERM recurrence is relatively high after surgery.
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Affiliation(s)
- M J Banach
- Retina Consultants, PC, Camp Hill, Pennsylvania, USA
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Sarrafizadeh R, Ruby AJ, Hassan TS, Williams GA, Garretson BR, Trese MT, Margherio RR. A comparison of visual results and complications in eyes with posterior chamber intraocular lens dislocation treated with pars plana vitrectomy and lens repositioning or lens exchange. Ophthalmology 2001; 108:82-9. [PMID: 11150269 DOI: 10.1016/s0161-6420(00)00410-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [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: 11/19/2022] Open
Abstract
PURPOSE To compare the visual results and the postoperative complications in eyes with posterior chamber intraocular lens (PCIOL) dislocation that underwent pars plana vitrectomy with lens repositioning with eyes that underwent pars plana vitrectomy with lens exchange. DESIGN Nonrandomized consecutive comparative case series. PARTICIPANTS Fifty-nine eyes (27 right eyes and 32 left eyes) of 56 subjects (28 women and 28 men) ranging in age from 59 to 90 years. Mean follow-up was 34 months. METHODS A comparison of the best-corrected preoperative visual acuities, final visual acuities, and postoperative complications in subjects with dislocated PCIOLs that underwent pars plana vitrectomy. Logarithm of the minimum angle of resolution (LogMAR)-converted visual acuities were used for comparison. Categorical data were analyzed by Fisher's exact test, and population means were compared by a pooled Student's t test. MAIN OUTCOME MEASURES Final mean visual acuities, change in mean visual acuities, and postoperative complications. RESULTS For all 59 eyes the mean preoperative visual acuity was 20/152, and the mean final visual acuity was 20/48. Final visual results were similar between the eyes that underwent lens repositioning (20/55) and the eyes that underwent lens exchange (20/43; P = 0.19). Final visual results were also similar between the eyes that underwent lens exchange with sutured PCIOL placement (20/51) and the eyes that underwent lens exchange with anterior chamber intraocular lens (ACIOL) placement (20/38; P = 0.26). Final mean visual acuity in eyes that received an ACIOL (20/38) was better than in eyes that underwent repositioning of the dislocated lens into the ciliary sulcus (20/65; P = 0.01). The mean increase in visual acuities was greater for eyes with ACIOL placement compared with eyes with sutured PCIOL placement (P = 0.01). For all eyes, final visual results were unaffected by a concurrent diagnosis of age-related macular degeneration (20/52; P: = 0.71), glaucoma (20/48; P = 0.95), or postoperative cystoid macular edema (20/55; P = 0.45). Final visual acuities were significantly worse in eyes with a detectable preoperative afferent pupillary defect (20/200; P<0.0001). Postoperative retinal detachments developed in 4 of 29 eyes (14%) that underwent lens repositioning and in 2 of 30 eyes (7%) that had lens exchange (P = 0.42). Postoperative lens subluxations occurred in 6 of 29 eyes (21%) that underwent lens repositioning and in 1 of 30 eyes (3%) that underwent lens exchange (P = 0.05). CONCLUSIONS The final visual results in eyes with dislocated PCIOLs that underwent pars plana vitrectomy with lens repositioning were similar to the visual results obtained in eyes that underwent pars plana vitrectomy with lens exchange. For eyes that underwent lens exchange, final visual results in eyes that received an ACIOL were similar to the visual results obtained in eyes that received a PCIOL; however, eyes with an ACIOL showed a greater increase in mean visual acuity. Eyes with a preoperative afferent pupillary defect had worse final visual results.
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Affiliation(s)
- R Sarrafizadeh
- Associated Retinal Consultants, PC, William Beaumont Hospital, Royal Oak, Michigan, USA
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Williams GA, Adam P, Mound LA. Thrips (Thysanoptera) pollination in Australian subtropical rainforests, with particular reference to pollination ofWilkiea huegeliana(Monimiaceae). J NAT HIST 2001. [DOI: 10.1080/002229301447853] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Serena M, Worley M, Swinnerton M, Williams GA. Effect of food availability and habitat on the distribution of platypus (Ornithorhynchus anatinus) foraging activity. AUST J ZOOL 2001. [DOI: 10.1071/zo00089] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
While the diet of the platypus
(Ornithorhynchus anatinus) is known to include a wide
range of benthic macro-invertebrates, little is known about how the animals
distribute their feeding behaviour along a waterway. This radio-tracking study
aimed to determine whether the spatial distribution of platypus foraging
activity varied in relation to habitat attributes and/or the amount of
food present along a southern Victorian stream. Five
O. anatinus were tracked nocturnally for a total of
nearly 95 h in March and April 2000. Attributes of the channel and bank were
described both in the area used by the animals and adjoining unused sections
of stream, and macro-invertebrates were sampled quantitatively in six
substrates that varied in abundance in the used and unused areas. Eleven
habitat variables showed a significant positive relationship with the
occurrence of platypus activity (including the number of medium and large
Eucalyptus, Acacia and
Populus trees growing along the bank; presence of
gravel, pebbles, cobbles, large rocks and coarse particulate organic matter in
the channel substrate; amount of riffle habitat; amount of large woody debris
in the channel; and amount of undercut banks). Six habitat variables showed a
significant negative relationship with platypus activity (including the number
of medium and large Salix trees growing along the bank;
the presence of silt, solid clay and Salix roots in the
channel substrate; the amount of pool habitat; and the maximum channel depth).
Substrates that were relatively abundant in the area used by
O. anatinus (gravel/pebbles,
Eucalyptus litter, Populus litter)
did not consistently support more macro-invertebrates than substrates that
dominated the unused area (silt, Salix roots,
Salix litter). This may reflect the fact that the
platypus population was not food-limited (and hence not under pressure to
optimise foraging) at the time of the study, that platypus feeding patterns
were influenced by habitat features that were not considered in relation to
invertebrate abundance, or that the choice of foraging areas by
O. anatinus may be influenced by factors other than the
total abundance of food items, e.g. the nutritional quality and/or
accessibility of prey.
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Berinstein DM, Hassan TS, Williams GA, Margherio RR, Ruby AJ, Garretson BR. Surgical repair of full-thickness idiopathic macular holes associated with significant macular drusen. Ophthalmology 2000; 107:2233-9. [PMID: 11097602 DOI: 10.1016/s0161-6420(00)00417-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE To evaluate the visual and anatomic results of surgically repaired macular holes in eyes with intermediate or large-sized macular drusen. DESIGN Retrospective noncomparative case series. PARTICIPANTS Thirty-four eyes of 32 patients undergoing macular hole surgery with preoperative intermediate or large-sized macular drusen as defined by the Age-Related Eye Disease Study (AREDS). INTERVENTION Pars plana vitrectomy for standard macular hole repair performed by multiple surgeons. MAIN OUTCOME MEASURES Visual acuity, anatomic hole closure. RESULTS Initial hole closure failed in 8 eyes (24%) overall, 5 of 28 eyes (18%) with AREDS category 2 drusen and 3 of 6 eyes (50%) with category 3 drusen (P = 0.1263). Final macular hole closure was seen in 93% of category 2 and 67% of category 3 eyes (P = 0.1347). Mean final visual acuity was 20/60 overall, 20/60 for category 2, and 20/50 for category 3 eyes. CONCLUSIONS A trend of reduced initial macular hole closure was seen in eyes with significant macular drusen. Reoperation improved closure rates. If closure was accomplished, visual outcomes were excellent.
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Affiliation(s)
- D M Berinstein
- Associated Retinal Consultants, PC, Department of Ophthalmology, Beaumont Eye Institute, Royal Oak, Michigan, USA
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Mansur AH, Williams GA, Bishop DT, Markham AF, Lewis S, Britton J, Morrison JF. Evidence for a role of HLA DRB1 alleles in the control of IgE levels, strengthened by interacting TCR A/D marker alleles. Clin Exp Allergy 2000; 30:1371-8. [PMID: 10998012 DOI: 10.1046/j.1365-2222.2000.00944.x] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND MHC class II alleles at human chromosome 6p21.1 and alleles in the TCR A/D locus at human chromosome 14q11.2 have been implicated in susceptibility to specific allergies and the modulation of total serum IgE. It has also been hypothesized that HLA and TCR allelic interactions may have a strong influence on predisposition to allergic disease. OBJECTIVE This study was performed to investigate the influence of HLA-DRB and DQB1 alleles and D14S50 alleles (adjacent to TCR A/D locus on 14q11.2), individually and in-combination, on total serum IgE levels, and on the development of specific allergies. METHODS We performed an association study between HLA-DRB, HLA-DQB1 polymorphisms, D14S50 alleles, total serum IgE expression and specific allergies to house dust mite, grass pollens and cat fur. A sample of 181 individuals was drawn from a larger set of 2415 adults, sampled at random from a district in Nottingham. RESULTS Strong association was observed between HLA-DRB1*0701 allele and high total serum IgE expression (P < 0.001). D14S50 alleles alone showed no evidence for independent association. However, there was a significant interaction between DRB1*0701 and D14S50 allele 170 such that, when both were present, there was a further increase in total serum IgE levels. CONCLUSION This study suggests that DRB1*0701 allele is involved in the modulation of total serum IgE, and that there is an interaction between DRB1*0701 and a marker adjacent to TCR A/D in the control of IgE expression.
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Affiliation(s)
- A H Mansur
- Molecular Medicine Unit, University of Leeds, Clinical Sciences Building, St. James's University Hospital, Leeds, UK
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Williams GA, Sarrafizadeh R. Antiphospholipid antibodies and retinal thrombosis in patients without risk factors: a prospective case-control study. Am J Ophthalmol 2000; 130:538-9. [PMID: 11183560 DOI: 10.1016/s0002-9394(00)00565-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
PURPOSE The purpose of this article is to demonstrate the feasibility of a surgical approach that might be possible in an office setting for idiopathic stage 3 macular holes. The posterior hyaloid of the vitreous and perihole tissue is enzymatically manipulated to create an atraumatic posterior vitreous separation and may stimulate cell proliferation to close macular holes. DESIGN Prospective noncomparative interventional case series. PARTICIPANTS Nine eyes of eight patients with idiopathic stage 3 macular holes were treated. METHODS The patients were treated with an injection of 0.4 IU of autologous plasmin enzyme into the midvitreous cavity and lavage of the vitreous cavity with an infusion light pipe and vitreous cutter followed by filling 70% to 80% of the vitreous cavity with 14% C3F8 and head-down positioning. MAIN OUTCOME MEASURES Posterior vitreous detachment, macular hole closure, and vision improvement. RESULTS Eight of nine eyes showed a spontaneous posterior vitreous detachment. One eye required minimal suction of less than 50 mmHg to elevate the posterior hyaloid off the retinal surface. Eyes were followed for a minimum of 6 months. All holes closed, and there was an average visual acuity improvement of four lines. The average surgical time for this procedure was 20 minutes. CONCLUSIONS Autologous plasmin enzyme-assisted vitreous surgery techniques can reduce operative time, expense, and patient inconvenience while maintaining excellent surgical results, which may allow office-based vitreous surgery for idiopathic stage 3 macular holes.
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Affiliation(s)
- M T Trese
- Associated Retinal Consultants, PC, Royal Oak, Michigan, USA
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Pendergast SD, Hassan TS, Williams GA, Cox MS, Margherio RR, Ferrone PJ, Garretson BR, Trese MT. Vitrectomy for diffuse diabetic macular edema associated with a taut premacular posterior hyaloid. Am J Ophthalmol 2000; 130:178-86. [PMID: 11004291 DOI: 10.1016/s0002-9394(00)00472-4] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.0] [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: 12/11/2022]
Abstract
PURPOSE To evaluate the role of vitrectomy in eyes with diffuse diabetic macular edema associated with a taut posterior hyaloid. METHODS Records of 55 eyes of 50 patients with diabetic retinopathy and diffuse clinically significant diabetic macular edema who underwent vitrectomy with stripping of the premacular posterior hyaloid were reviewed. In all 55 eyes, diffuse diabetic macular edema was present on contact lens examination and confirmed with fluorescein angiography. On fundus examination, the premacular posterior hyaloid was attached and appeared taut. RESULTS The mean preoperative best-corrected visual acuity was 20/160, and the mean final best-corrected visual acuity was 20/80 (P <.0001, Wilcoxon signed rank test), with 27 (49.1%) of the 55 eyes demonstrating improvement in best-corrected visual acuity of 2 or more lines. Fifty-two (94.5%) of the 55 vitrectomized eyes showed improvement in clinically significant macular edema and in 45 eyes (81.8%) the macular edema resolved completely during a mean period of 4.5 months (range, 1 to 13 months). Eyes with macular ischemia and preoperative best-corrected visual acuity of 20/200 or less tended to respond less favorably to vitrectomy than eyes lacking these characteristics. All eyes had at least 6 months of follow-up after surgery, with a mean follow-up of 23.2 months. CONCLUSION In eyes with persistent diffuse diabetic macular edema with a taut premacular posterior hyaloid face unresponsive to laser therapy, vitrectomy with removal of the posterior hyaloid appears to be beneficial in some cases. Careful selection of eyes with favorable preoperative clinical characteristics may improve surgical outcomes.
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Affiliation(s)
- S D Pendergast
- Retina Associates of Cleveland, Inc, Beachwood, Ohio 44122, USA.
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McCabe CM, Flynn HW, McLean WC, Brod RD, McDonald HR, Johnson MW, Williams GA, Mieler WF. Nonsurgical management of macular hemorrhage secondary to retinal artery macroaneurysms. Arch Ophthalmol 2000; 118:780-5. [PMID: 10865314 DOI: 10.1001/archopht.118.6.780] [Citation(s) in RCA: 26] [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] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To report visual acuity outcomes of nonsurgical management of macular hemorrhage secondary to retinal artery macroaneurysms. METHODS Forty-one patients at multiple centers with macular hemorrhage secondary to retinal artery macroaneurysms managed with observation alone were reviewed. Time to clearance of macular hemorrhage, visual acuity at final follow-up, and presence or absence of macular pigmentary changes after absorption of the hemorrhage were recorded for each patient. RESULTS On initial examination, visual acuity was 20/200 or worse in all except 4 patients (3 with 20/70, 1 with 20/80). At an average follow-up of 15. 7 months, a final visual acuity of 20/40 or better was achieved in 15 eyes (37%), between 20/50 and 20/100 in 12 (29%), and 20/200 or worse in 14 (34%). Macular pigmentary abnormalities were noted after clearance of the hemorrhage in 23 (56%) of 41 cases, and these eyes generally had worse visual acuity outcomes. CONCLUSIONS In eyes with macular hemorrhage secondary to retinal artery macroaneurysms managed with observation alone, good visual acuity outcomes can often be achieved. Poorer visual acuity outcomes are associated with macular pigmentary changes after resorption of blood. Arch Ophthalmol. 2000;118:780-785
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Affiliation(s)
- C M McCabe
- Bascom Palmer Eye Institute, 900 NW 17th St, Miami, FL 33136, USA.
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