35 results on '"Hudson SB"'
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2. Anthropogenic and climatic factors interact to influence reproductive timing and effort.
- Author
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Smith GD, Wilcoxen TE, Hudson SB, Virgin EE, Durso AM, Van der Walt M, Spence AR, Neuman-Lee LA, Webb AC, Terletzky PA, and French SS
- Abstract
Reproduction, although absolutely essential to a species' persistence, is in itself challenging. As anthropogenic change increasingly affects every landscape on Earth, it is critical to understand how specific pressures impact the reproductive efforts of individuals, which directly contribute to the success or failure of populations. However, organisms rarely encounter a single burden at a time, and the interactions of environmental challenges can have compounding effects. Understanding environmental and physiological pressures is difficult because they are often context-dependent and not generalizable, but long-term monitoring across variable landscapes and weather patterns can improve our understanding of these complex interactions. We tested the effects of urbanization, climate, and individual condition on the reproductive investment of wild side-blotched lizards ( Uta stansburiana ) by measuring physiological/reproductive metrics from six populations in urban and rural areas over six consecutive years of variable precipitation. We observed that reproductive stage affected body condition, corticosterone concentration, and oxidative stress. We also observed that reproductive patterns differed between urban and rural populations depending on rainfall, with rural animals increasing reproductive investment during rainier years compared to urban conspecifics, and that reproductive decisions appeared to occur early in the reproductive process. These results demonstrate the plastic nature of a generalist species optimizing lifetime fitness under varying conditions., Competing Interests: There are no conflicts of interests, financial or otherwise, for any of the authors., (© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
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- 2024
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3. Egg viability and egg mass underlie immune tradeoffs and differences between urban and rural lizard egg yolk physiology.
- Author
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Virgin EE, Lewis EL, Lidgard AD, Kepas ME, Marchetti JR, Hudson SB, Smith GD, and French SS
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- Animals, Female, Lipopolysaccharides, Reproduction physiology, Zygote, Egg Yolk metabolism, Lizards metabolism
- Abstract
Urbanization can cause innumerable abiotic and biotic changes that have the potential to influence the ecology, behavior, and physiology of native resident organisms. Relative to their rural conspecifics, urban Side-blotched Lizard (Uta stansburiana) populations in southern Utah have lower survival prospects and maximize reproductive investment via producing larger eggs and larger clutch sizes. While egg size is an important predictor of offspring quality, physiological factors within the egg yolk are reflective of the maternal environment and can alter offspring traits, especially during energetically costly processes, such as reproduction or immunity. Therefore, maternal effects may represent an adaptive mechanism by which urban-dwelling species can persist within a variable landscape. In this study, we assess urban and rural differences in egg yolk bacterial killing ability (BKA), corticosterone (CORT), oxidative status (d-ROMs), and energy metabolites (free glycerol and triglycerides), and their association with female immune status and egg quality. Within a laboratory setting, we immune challenged urban lizards via lipopolysaccharide injection (LPS) to test whether physiological changes associated with immune system activity impacted egg yolk investment. We found urban females had higher mite loads than rural females, however mite burden was related to yolk BKA in rural eggs, but not urban eggs. While yolk BKA differed between urban and rural sites, egg mass and egg viability (fertilized vs. unfertilized) were strong predictors of yolk physiology and may imply tradeoffs exist between maintenance and reproduction. LPS treatment caused a decrease in egg yolk d-ROMs relative to the control treatments, supporting results from previous research. Finally, urban lizards laid a higher proportion of unfertilized eggs, which differed in egg yolk BKA, CORT, and triglycerides in comparison to fertilized eggs. Because rural lizards laid only viable eggs during this study, these results suggest that reduced egg viability is a potential cost of living in an urban environment. Furthermore, these results help us better understand potential downstream impacts of urbanization on offspring survival, fitness, and overall population health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
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4. Glucose tolerance of iguanas is affected by high-sugar diets in the lab and supplemental feeding by ecotourists in the wild.
- Author
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French SS, Hudson SB, Webb AC, Knapp CR, Virgin EE, Smith GD, Lewis EL, Iverson JB, and DeNardo DF
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- Animals, Animals, Wild, Blood Glucose, Diet veterinary, Humans, Iguanas
- Abstract
There is great interspecific variation in the nutritional composition of natural diets, and the varied nutritional content is physiologically tolerated because of evolutionarily based balances between diet composition and processing ability. However, as a result of landscape change and human exposure, unnatural diets are becoming widespread among wildlife without the necessary time for evolutionary matching between the diet and its processing. We tested how a controlled, unnatural high glucose diet affects glucose tolerance using captive green iguanas, and we performed similar glucose tolerance tests on wild Northern Bahamian rock iguanas that are either frequently fed grapes by tourists or experience no such supplementation. We evaluated both short and longer-term blood glucose responses and corticosterone (CORT) concentrations as changes have been associated with altered diets. Experimental glucose supplementation in the laboratory and tourist feeding in the wild both significantly affected glucose metabolism. When iguanas received a glucose-rich diet, we found greater acute increases in blood glucose following a glucose challenge. Relative to unfed iguanas, tourist-fed iguanas had significantly lower baseline CORT, higher baseline blood glucose, and slower returns to baseline glucose levels following a glucose challenge. Therefore, unnatural consumption of high amounts of glucose alters glucose metabolism in laboratory iguanas with short-term glucose treatment and free-living iguanas exposed to long-term feeding by tourists. Based on these results and the increasing prevalence of anthropogenically altered wildlife diets, the consequences of dietary changes on glucose metabolism should be further investigated across species, as such changes in glucose metabolism have health consequences in humans (e.g. diabetes)., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)
- Published
- 2022
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5. Energy expenditure across immune challenge severities in a lizard: consequences for innate immunity, locomotor performance and oxidative status.
- Author
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Hudson SB, Virgin EE, Kepas ME, and French SS
- Subjects
- Animals, Basal Metabolism, Energy Metabolism, Immunity, Innate, Male, Oxidative Stress, Lizards
- Abstract
Reptiles, like other vertebrates, rely on immunity to defend themselves from infection. The energetic cost of an immune response is liable to scale with infection severity, prompting constraints on other self-maintenance traits if immune prioritization exceeds energy budget. In this study, adult male side-blotched lizards (Uta stansburiana) were injected with saline (control) or high (20 µg g-1 body mass) or low (10 µg g-1 body mass) concentrations of lipopolysaccharide (LPS) to simulate bacterial infections of discrete severities. The costs and consequences of the immune response were assessed through comparisons of change in resting metabolic rate (RMR), energy metabolites (glucose, glycerol, triglycerides), innate immunity (bactericidal ability), sprint speed and oxidative status (antioxidant capacity, reactive oxygen metabolites). High-LPS lizards had the lowest glucose levels and greatest sprint reductions, while their RMR and bactericidal ability were similar to those of control lizards. Low-LPS lizards had elevated RMR and bactericidal ability, but glucose levels and sprint speed changes between those of high-LPS and control lizards. Levels of glycerol, triglycerides, reactive oxygen metabolites and antioxidant capacity did not differ by treatment. Taken together, energy expenditure for the immune response varies in a non-linear fashion with challenge severity, posing consequences for performance and self-maintenance processes in a reptile., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)
- Published
- 2021
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6. Recovery from discrete wound severities in side-blotched lizards (Uta stansburiana): implications for energy budget, locomotor performance, and oxidative stress.
- Author
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Hudson SB, Virgin EE, Brodie ED Jr, and French SS
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- Animals, Antioxidants, Male, Oxidative Stress, Predatory Behavior, Wound Healing, Lizards
- Abstract
Wounding events (predation attempts, competitive combat) result in injuries and/or infections that induce integrated immune responses for the recovery process. Despite the survival benefits of immunity in this context, the costs incurred may require investment to be diverted from traits contributing to immediate and/or future survival, such as locomotor performance and oxidative status. Yet, whether trait constraints manifest likely depends on wound severity and the implications for energy budget. For this study, food intake, body mass, sprint speed, and oxidative indices (reactive oxygen metabolites, antioxidant capacity) were monitored in male side-blotched lizards (Uta stansburiana) healing from cutaneous wounds of discrete sizes (control, small, large). Results indicate that larger wounds induced faster healing, reduced food consumption, and led to greater oxidative stress over time. Granted wounding did not differentially affect body mass or sprint speed overall, small-wounded lizards with greater wound area healed had faster sprint speeds while large-wounded lizards with greater wound area healed had slower sprint speeds. During recovery from either wound severity, however, healing and sprint performance did not correspond with food consumption, body mass loss, nor oxidative status. These findings provide support that energy budget, locomotor performance, and oxidative status of a reptile are linked to wound recovery to an extent, albeit dependent on wound severity.
- Published
- 2021
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7. Standing genetic variation in laboratory populations of insecticide-susceptible Phlebotomus papatasi and Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) for the evolution of resistance.
- Author
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Denlinger DS, Hudson SB, Keweshan NS, Gompert Z, and Bernhardt SA
- Abstract
Insecticides can exert strong selection on insect pest species, including those that vector diseases, and have led to rapid evolution of resistance. Despite such rapid evolution, relatively little is known about standing genetic variation for resistance in insecticide-susceptible populations of many species. To help fill this knowledge gap, we generated genotyping-by-sequencing data from insecticide-susceptible Phlebotomus papatasi and Lutzomyia longipalpis sand flies that survived or died from a sub-diagnostic exposure to either permethrin or malathion using a modified version of the Centers for Disease Control and Prevention bottle bioassay. Multi-locus genome-wide association mapping methods were used to quantify standing genetic variation for insecticide resistance in these populations and to identify specific alleles associated with insecticide survival. For each insecticide treatment, we estimated the proportion of the variation in survival explained by the genetic data (i.e., "chip" heritability) and the number and contribution of individual loci with measurable effects. For all treatments, survival to an insecticide exposure was heritable with a polygenic architecture. Both P . papatasi and L . longipalpis had alleles for survival that resided within many genes throughout their genomes. The implications for resistance conferred by many alleles, as well as inferences made about the utility of laboratory insecticide resistance association studies compared to field observations, are discussed., (© 2021 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.)
- Published
- 2021
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8. Warmer temperatures interact with salinity to weaken physiological facilitation to stress in freshwater fishes.
- Author
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Walker RH, Smith GD, Hudson SB, French SS, and Walters AW
- Abstract
Management of stressors requires an understanding of how multiple stressors interact, how different species respond to those interactions and the underlying mechanisms driving observed patterns in species' responses. Salinization and rising temperatures are two pertinent stressors predicted to intensify in freshwater ecosystems, posing concern for how susceptible organisms achieve and maintain homeostasis (i.e. allostasis). Here, glucocorticoid hormones (e.g. cortisol), responsible for mobilizing energy (e.g. glucose) to relevant physiological processes for the duration of stressors, are liable to vary in response to the duration and severity of salinization and temperature rises. With field and laboratory studies, we evaluated how both salinity and temperature influence basal and stress-reactive cortisol and glucose levels in age 1+ mottled sculpin ( Cottus bairdii ), mountain sucker ( Catostomus platyrhynchus ) and Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ). We found that temperature generally had the greatest effect on cortisol and glucose concentrations and the effect of salinity was often temperature dependent. We also found that when individuals were chronically exposed to higher salinities, baseline concentrations of cortisol and glucose usually declined as salinity increased. Reductions in baseline concentrations facilitated stronger stress reactivity for cortisol and glucose when exposed to additional stressors, which weakened as temperatures increased. Controlled temperatures near the species' thermal maxima became the overriding factor regulating fish physiology, resulting in inhibitory responses. With projected increases in freshwater salinization and temperatures, efforts to reduce the negative effects of increasing temperatures (i.e. increased refuge habitats and riparian cover) could moderate the inhibitory effects of temperature-dependent effects of salinization for freshwater fishes., (© The Author(s) 2020. Published by Oxford University Press and the Society for Experimental Biology.)
- Published
- 2020
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9. Long-term monitoring of two snake species reveals immune-endocrine interactions and the importance of ecological context.
- Author
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Spence AR, French SS, Hopkins GR, Durso AM, Hudson SB, Smith GD, and Neuman-Lee LA
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- Animals, Blood Bactericidal Activity, Body Temperature, Colubridae blood, Colubridae immunology, Corticosterone blood, Environment, Female, Male, Seasons, Sex Factors, Testosterone blood, Colubridae physiology
- Abstract
While there is huge promise in monitoring physiological parameters in free-living organisms, we also find high amounts of variability over time and space. This variation requires us to capitalize on long-term physiological monitoring to adequately address questions of population health, conservation status, or evolutionary trends as long-term sampling can examine ecoimmunological and endocrine interactions in wild populations while accounting for the variation that often makes ecophysiological field studies difficult to compare. In this study, we tested how immune efficacy and endocrinology interact while accounting for ecological context and environmental conditions in two snake species. Specifically, we measured bacterial killing ability, steroid hormones, and morphological characteristics in multiple populations of the Western Terrestrial Gartersnake (Thamnophis elegans) and Common Gartersnake (T. sirtalis) for multiple seasons over 6 years. Leveraging this long-term dataset, we tested how a broad immune measure and endocrine endpoints interact while accounting for individual traits, sampling date, and environmental conditions. Across both species, we found bacterial killing ability to be directly related to corticosterone (CORT) and temperature and greater overall in the spring compared to the fall. We found CORT and testosterone yielded relationships with individual sex, sampling temperature, and time of year. Wild populations can exhibit high amounts of variation in commonly collected physiological endpoints, highlighting the complexity and difficulty inherent in interpreting single endpoints without taking ecological and environmental conditions into account. Our study emphasizes the importance of reporting the environmental conditions under which the sampling occurred to allow for better contextualization and comparison between studies., (© 2021 Wiley Periodicals LLC.)
- Published
- 2020
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10. Glucocorticoids, energy metabolites, and immunity vary across allostatic states for plateau side-blotched lizards (Uta stansburiana uniformis) residing in a heterogeneous thermal environment.
- Author
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Hudson SB, Lidgard AD, and French SS
- Subjects
- Animals, Blood Bactericidal Activity, Blood Glucose analysis, Body Temperature physiology, Corticosterone blood, Environment, Lizards metabolism, Lizards physiology, Male, Stress, Physiological immunology, Stress, Physiological physiology, Temperature, Energy Metabolism physiology, Glucocorticoids metabolism, Lizards immunology
- Abstract
Reptiles rely on thermal heat exchange to achieve body temperatures (T
body ) conducive to maintaining homeostasis. Diurnal changes in the thermal environment are therefore liable to influence allostatic mediation of survival processes (e.g., immunity) during environmental challenges or stressors. However, the extent to which Tbody prompts individual variation in physiology remains largely unexplored in reptiles. Our study tested how circulating energy-mobilizing hormone, energy metabolites, and immunity can vary across basal and stress-induced allostatic states for plateau side-blotched lizards (Uta stansburiana uniformis) residing in a heterogeneous thermal environment. We collected baseline and acute stress blood samples from male lizards to compare changes in plasma corticosterone (CORT), glucose, and bacterial killing ability (BKA) in relation to each other and Tbody . We hypothesized each physiological parameter differs between allostatic states, whereby stress-induced activity increases from baseline. At basal and stress-induced states, we also hypothesized circulating CORT, glucose, and BKA directly correspond with each other and Tbody . We found both CORT and BKA increased while glucose instead decreased from acute stress. At basal and stress-induced allostatic states, we found CORT to be directly related to Tbody while BKA was inversely related to CORT. We also found BKA and glucose were directly related at baseline, but inversely related following acute stress. Overall, these results demonstrate allostatic outcomes from acute stress in a free-living reptile and the role of temperature in mediating energetic state and immunity. Future research on reptilian allostasis should consider multiple environmental conditions and their implications for physiological performance and survival., (© 2020 Wiley Periodicals LLC.)- Published
- 2020
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11. Steroid hormones, energetic state, and immunocompetence vary across reproductive contexts in a parthenogenetic lizard.
- Author
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Hudson SB, Kluever BM, Webb AC, and French SS
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- Animals, Corticosterone blood, Estradiol blood, Female, Lizards metabolism, Male, Oviparity physiology, Parthenogenesis physiology, Seasons, Vitellogenesis physiology, Energy Metabolism physiology, Gonadal Steroid Hormones metabolism, Immunocompetence physiology, Lizards physiology, Reproduction physiology
- Abstract
Reproduction is energetically expensive and investing in this life history trait is likely accompanied by significant changes in physiological activity. Investment strategy necessary for achieving reproductive success in reptiles can vary with reproductive form and pattern, potentiating different consequences for competing fitness-related traits such as those key to survival. The goal of this study was to assess if and how energetic state (i.e., energy metabolites) and self-maintenance (i.e., immunocompetence) are hormonally modulated across reproductive contexts in an oviparous, parthenogenetic lizard, the Colorado Checkered Whiptail Aspidoscelis neotesselata. Here blood plasma samples were collected from lizards within the US Army Fort Carson Military Installation near Colorado Springs, CO, USA, during seasons of reproductive activity (i.e., June) and inactivity (i.e., August). Measures of reproductive (i.e., estradiol) and energy-mobilizing (i.e., corticosterone) hormones, energy metabolites (i.e., glucose, triglycerides, and free glycerol), and innate immunity (i.e., bactericidal ability) were compared by season and reproductive stage. Levels of energy metabolites and bactericidal ability were compared to levels of E
2 and CORT. Bactericidal ability was also compared to levels of energy metabolites. Corticosterone and glucose levels were lower during the reproductive season while triglyceride levels and bactericidal ability were higher, but both estradiol and free glycerol levels did not differ between seasons. Throughout vitellogenesis, corticosterone and glucose levels as well as bactericidal ability did not differ, but estradiol levels were higher during early and mid-stage and both triglyceride and free glycerol levels were lower during gravidity. Corticosterone levels were negatively associated with circulating triglycerides and bactericidal ability, but were not related to glucose nor free glycerol levels. Estradiol levels were positively associated with free glycerol levels and bactericidal ability, but were not related to glucose nor triglyceride levels. Finally, bactericidal ability was negatively associated with glucose, but positively associated with triglycerides. Differences in energetic state and immunocompetence are thus reflected by shifts in hormone secretion across reproductive investment. These findings provide partial support for the hypothesis that energetic state is differentially regulated by steroid hormones to afford reproduction, potentially at the cost of future survival., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2020
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12. Stoichiometric and stable isotope ratios of wild lizards in an urban landscape vary with reproduction, physiology, space and time.
- Author
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Durso AM, Smith GD, Hudson SB, and French SS
- Abstract
Spatial and temporal variation in stoichiometric and stable isotope ratios of animals contains ecological information that we are just beginning to understand. In both field and lab studies, stoichiometric or isotopic ratios are related to physiological mechanisms underlying nutrition or stress. Conservation and ecosystem ecology may be informed by isotopic data that can be rapidly and non-lethally collected from wild animals, especially where human activity leaves an isotopic signature (e.g. via introduction of chemical fertilizers, ornamental or other non-native plants or organic detritus). We examined spatial and temporal variation in stoichiometric and stable isotope ratios of the toes of Uta stansburiana (side-blotched lizards) living in urban and rural areas in and around St. George, Utah. We found substantial spatial and temporal variation as well as context-dependent co-variation with reproductive physiological parameters, although certain key predictions such as the relationship between δ
15 N and body condition were not supported. We suggest that landscape change through urbanization can have profound effects on wild animal physiology and that stoichiometric and stable isotope ratios can provide unique insights into the mechanisms underlying these processes., (© The Author(s) 2020. Published by Oxford University Press and the Society for Experimental Biology.)- Published
- 2020
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13. Investigating the relationship between corticosterone and glucose in a reptile.
- Author
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Neuman-Lee LA, Hudson SB, Webb AC, and French SS
- Subjects
- Animals, Colubridae blood, Male, Utah, Blood Glucose metabolism, Colubridae metabolism, Corticosterone blood
- Abstract
The glucocorticoid hormone corticosterone (CORT) has classically been used in ecophysiological studies as a proxy for stress and energy mobilization, but rarely are CORT and the energy metabolites themselves concurrently measured. To examine CORT's role in mobilizing glucose in a wild reptile, we conducted two studies. The first study measured natural baseline and stress-induced blood-borne CORT and glucose levels in snakes during spring emergence and again when snakes return to the denning sites in autumn. The second study manipulated the hypothalamic-pituitary-adrenal (HPA) axis in male snakes in the autumn by taking a baseline blood sample, then subjecting individuals to one of five treatments (no injection, saline, CORT, adrenocorticotropin hormone and metyrapone). Subsequent samples were taken at 30 and 60 min. In both studies, we found that glucose levels do increase with acute stress, but that the relationship was not directly related to CORT elevation. In the second study, we found that none of the HPA axis manipulations directly affected blood glucose levels, further indicating that CORT may play a complex but not direct role in glucose mobilization in snakes. This study highlights the need for testing mechanisms in wild organisms by combining in situ observations with manipulative studies., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)
- Published
- 2020
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14. Town and Country Reptiles: A Review of Reptilian Responses to Urbanization.
- Author
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French SS, Webb AC, Hudson SB, and Virgin EE
- Subjects
- Animals, Research, Urbanization, Ecosystem, Reptiles
- Abstract
The majority of the world population is now inhabiting urban areas, and with staggering population growth, urbanization is also increasing. While the work studying the effects of changing landscapes and specific urban pressures on wildlife is beginning to amass, the majority of this work focuses on avian or mammalian species. However, the effects of urbanization likely vary substantially across taxonomic groups due to differences in habitat requirements and life history. The current article aims first to broaden the review of urban effects across reptilian species; second, to summarize the responses of reptilian fauna to specific urban features; and third, to assess the directionality of individual and population level responses to urbanization in reptile species. Based on our findings, urban research in reptilian taxa is lacking in the following areas: (1) investigating interactive or additive urban factors, (2) measuring multiple morphological, behavioral, and physiological endpoints within an animal, (3) linking individual to population-level responses, and (4) testing genetic/genomic differences across an urban environment as evidence for selective pressures.
- Published
- 2018
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15. Emotional Impact of Reduced Access to Assisted Reproductive Care.
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Tatpati LL, Hudson SB, Ehlers SL, and Coddington CC 3rd
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- Adaptation, Psychological, Adult, Continuity of Patient Care, Cross-Sectional Studies, Female, Humans, Infertility, Female, Male, Middle Aged, Odds Ratio, Reproductive Techniques, Assisted, Surveys and Questionnaires, Young Adult, Health Facility Closure, Health Services Accessibility, Infertility psychology, Quality of Life psychology, Reproductive Health Services, Stress, Psychological psychology
- Abstract
Objective: To evaluate the impact of cessation of fertility services on patients with infertility., Study Design: A cross-sectional, anonymous mail survey was conducted in a university hospital setting. A total of 281 female infertility patients treated from 2003-2006 were mailed surveys. The main outcome measures of the study were the Perceived Stress Scale 10 (PSS-10) and the Impact of Events Scale (IES)., Results: Of the 281 patients, 175 (62.3%) responded to the questionnaire. Of those, 51 (29.1%) reported being affected by the closure. The majority (58.9%) reported a somewhat or very negative impact on their perceived quality of life. Affected patients were more likely than unaffected patients to have an elevated PSS-10 result (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.04-4.3). No significant difference was seen in IES results, with 90.2% of affected and 81.5% of unaffected patients scoring in the high distress range (OR 2.1, 95% CI 0.77-5.65). Self-reported average stress levels were reduced following news of resumption of services (3.3, scale 1-10) as compared to both prior to (5.1) and during (7.4) the closure., Conclusion: When fertility services are discontinued, there may be significant emotional distress among the population affected. Health care providers should be aware of the impact infertility has on stress-coping and quality of life and be prepared to offer psychological services.
- Published
- 2015
16. Factors associated with ovarian hyperstimulation syndrome (OHSS) and its effect on assisted reproductive technology (ART) treatment and outcome.
- Author
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Luke B, Brown MB, Morbeck DE, Hudson SB, Coddington CC 3rd, and Stern JE
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- Adult, Cohort Studies, Ethnicity statistics & numerical data, Female, Humans, Infant, Newborn, Live Birth epidemiology, Ovarian Hyperstimulation Syndrome epidemiology, Ovarian Hyperstimulation Syndrome ethnology, Pregnancy, Pregnancy Outcome epidemiology, Pregnancy Rate, Risk Factors, Treatment Outcome, Ovarian Hyperstimulation Syndrome complications, Ovarian Hyperstimulation Syndrome etiology, Reproductive Techniques, Assisted adverse effects, Reproductive Techniques, Assisted statistics & numerical data
- Abstract
Objective: To evaluate factors associated with ovarian hyperstimulation syndrome (OHSS) and its effect on assisted reproductive technology (ART) treatment and outcome., Design: Historic cohort study., Setting: Clinic-based data., Patient(s): The population included 214,219 ART cycles performed during 2004 to 2006 and reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System Online database. The study population was limited to cycles of autologous, fresh embryo transfers to women without any treatment complications (212,041), and those developing moderate (1,523) or severe (655) OHSS., Intervention(s): None., Main Outcome Measure(s): Risk factors for developing OHSS, and its effect on achieving a pregnancy and live birth, as adjusted odds ratios., Result(s): Compared with white women, the risk of developing OHSS was increased for Black women (any OHSS, 1.88; severe OHSS, 2.93) and decreased for Hispanic women (any OHSS, 0.79). Ovarian hyperstimulation syndrome was associated with ovulation disorders (2.01), tubal factors (1.24), and unexplained factors (1.36). Ovarian hyperstimulation syndrome increased the odds of achieving a pregnancy (1.98 with any OHSS, 2.68 with severe), a live birth (any OHSS, 1.86), and a multiple live birth (1.58 with any OHSS, 1.86 with severe). The presence of any OHSS increased the risk of an adverse pregnancy outcome (stillbirth, low birthweight, or preterm birth) by 26% and low birthweight among singletons by 40%., Conclusion(s): Ovarian hyperstimulation syndrome is associated with a higher likelihood of pregnancy, and multiple gestations, but also greater risks for adverse pregnancy outcomes., (Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
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17. Peroxides in mineral oil used for in vitro fertilization: defining limits of standard quality control assays.
- Author
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Hughes PM, Morbeck DE, Hudson SB, Fredrickson JR, Walker DL, and Coddington CC
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- Animals, Apoptosis drug effects, Benzene Derivatives analysis, Benzene Derivatives pharmacology, Blastomeres drug effects, Cell Count, Drug Contamination, Drug Stability, Drug Storage, Female, Humans, Indicators and Reagents standards, Male, Mice, Mineral Oil standards, Sperm Motility drug effects, Zygote drug effects, Biological Assay standards, Fertilization in Vitro, Mineral Oil chemistry, Peroxides analysis, Quality Control
- Abstract
Purpose: To determine the relative sensitivities of the 1 and 2-cell mouse embryo assays (MEA) and the human sperm motility assay (HSMA) for peroxides in mineral oil. The effect of peroxide on blastocyst cell number and apoptosis was also studied., Methods: One and two-cell MEA and HSMA were performed using mineral oil containing cumene hydroperoxide (CH)., Results: The 1-cell MEA was twice as sensitive as the 2-cell MEA and 20-times more sensitive than the HSMA for CH in mineral oil. The sensitivity of the 1-cell MEA doubled when embryos were cultured individually versus group culture. CH decreased blastocyst cell number in a dose dependent manner., Conclusions: Individually cultured 1-cell embryos had the highest sensitivity for peroxides in mineral oil. Current quality control assays, including group cultured murine embryos and human sperm motility, have limited sensitivity for peroxides in mineral oil and may not detect levels of peroxides that cause sub-lethal cellular damage.
- Published
- 2010
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18. Pre- versus postmenopausal age, estradiol, and peptide-secretagogue type determine pulsatile growth hormone secretion in healthy women: studies using submaximal agonist drive and an estrogen clamp.
- Author
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Hudson SB, Schroeder DR, Bailey JN, Mielke KL, Erickson D, Miles JM, Bowers CY, and Veldhuis JD
- Subjects
- Adult, Age Factors, Aged, Cohort Studies, Diagnostic Techniques, Endocrine, Double-Blind Method, Estradiol blood, Female, Growth Hormone-Releasing Hormone agonists, Health, Human Growth Hormone blood, Humans, Middle Aged, Placebos, Pulsatile Flow drug effects, Research Design, Young Adult, Estradiol administration & dosage, Growth Hormone-Releasing Hormone administration & dosage, Human Growth Hormone metabolism, Oligopeptides administration & dosage, Postmenopause blood, Postmenopause drug effects, Postmenopause physiology, Premenopause blood, Premenopause drug effects, Premenopause physiology
- Abstract
Context: GH-releasing peptide (GHRP), GHRH, and somatostatin are physiological regulators of pulsatile GH secretion., Hypothesis: Age, independently of abdominal visceral fat (AVF) and basal (nonpulsatile) GH secretion, damps pulsatile GH secretion driven by physiological (rather than pharmacological) amounts of GHRP and GHRH in an experimentally controlled estradiol (E(2)) milieu., Design and Setting: A prospectively randomized, double-blind parallel-cohort study was conducted at an academic medical center., Participants: Community-dwelling healthy premenopausal (PRE, age 24 +/- 0.8 yr, n = 20) and postmenopausal (POST, age 63 +/- 1.8 yr, n = 22) women participated in the study., Interventions: Gonadal-axis down-regulation with leuprolide was followed by randomized addback of placebo or transdermal E(2) and separate-day iv bolus injections of a half-maximally stimulatory dose of GHRP-2 or GHRH (each 0.33 mug/kg)., Analysis: Three-way analysis of covariance included main factors age, E(2) status, and secretagogue type and covariates AVF and basal GH secretion., Results: Submaximally stimulated pulsatile GH secretion was positively determined by PRE vs. POST age (P < 0.001), E(2) repletion vs. depletion (P = 0.001) and GHRP-2 vs. GHRH stimulation (P < 0.001), after adjustment for AVF and basal secretion. E(2) vs. placebo elevated fasting mean GH concentrations in both PRE and POST women (P = 0.006) but increased basal (nonpulsatile) GH secretion in PRE only (P = 0.002). PRE vs. POST age prolonged GHRH-driven GH secretory bursts by 36% (P = 0.006)., Conclusion: PRE vs. POST age, E(2) availability, and physiological peptide drive are triple determinants of pulsatile GH secretion independently of abdominal visceral fat and nonpulsatile GH secretion in healthy women.
- Published
- 2010
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19. High cumulative live births in oocyte donation cycles with cryopreservation of all embryos.
- Author
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Tatpati LL, Hudson SB, Gera PS, Allemand MC, Stevens-Hall S, Wentworth MA, and Coddington CC 3rd
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- Adult, Female, Humans, Kaplan-Meier Estimate, Pregnancy, Retrospective Studies, Cryopreservation statistics & numerical data, Embryo Transfer statistics & numerical data, Oocyte Donation statistics & numerical data, Pregnancy Outcome epidemiology, Pregnancy Rate
- Abstract
Background: Cryopreservation of all embryos in stimulated IVF cycles is occasionally necessary. Although it is known that frozen embryo transfer results in lower live birth rates per transfer, there is limited information regarding expected cumulative live birth rates for patients who are in this particular scenario., Methods: The objective was to evaluate long-term outcomes in cycles undergoing pronuclear cryopreservation of all embryos utilizing a retrospective analysis of 154 consecutive recipients from 1995 to 2006., Results: The cumulative rate of first live birth per retrieval was 66.2%, with a 36.4% live birth rate per frozen embryo transfer. Following an average 2.2 +/- 0.98 transfers, 32.6% (17/52) of patients who never delivered had remaining embryos making the cumulative first live birth rate previously stated a conservative estimate. 11.7% of recipients had sibling deliveries from a single retrieval. Over 1/3 of the delivered recipients have remaining cryopreserved embryos and could pursue an additional pregnancy., Conclusion: These results suggest that pronuclear cryopreservation of all embryos in an oocyte donation cycle maintains good cumulative live birth rates, as well as chances for a sibling from a single retrieval. Recipients who must delay transfer can be reassured a high potential for live birth from their first donor retrieval., (Copyright 2010 S. Karger AG, Basel.)
- Published
- 2010
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20. Relative effects of estrogen, age, and visceral fat on pulsatile growth hormone secretion in healthy women.
- Author
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Veldhuis JD, Hudson SB, Erickson D, Bailey JN, Reynolds GA, and Bowers CY
- Subjects
- Adolescent, Adult, Aged, Aging drug effects, Estradiol administration & dosage, Female, Gonadotropin-Releasing Hormone agonists, Health, Humans, Intra-Abdominal Fat drug effects, Leuprolide administration & dosage, Middle Aged, Placebos, Pulsatile Flow drug effects, Pulsatile Flow physiology, Young Adult, Aging physiology, Estradiol pharmacology, Human Growth Hormone metabolism, Intra-Abdominal Fat physiology
- Abstract
Growth hormone (GH) secretion is subject to complex regulation. How pre- and postmenopausal age (PRE, POST), estradiol (E(2)) availability, and abdominal visceral fat (AVF) jointly affect peptidyl-secretagogue drive of GH secretion is not known. To this end, healthy PRE (n = 20) and POST (n = 22) women underwent a low- vs. high-E(2) clamp before receiving a continuous intravenous infusion of GH-releasing hormone (GHRH) or GH-releasing peptide (GHRP-2). According to analysis of covariance, PRE and POST women achieved age-independent hypo- and euestrogenemia under respective low- and high-E(2) clamps. All four of age (P < 0.001), E(2) status (P = 0.006), secretagogue type (P < 0.001), and an age x peptide interaction (P = 0.014) controlled pulsatile GH secretion. Independently of E(2) status, POST women had lower GH responses to both GHRH (P = 0.028) and GHRP-2 (P < 0.001) than PRE women. Independently of age, GHRP-2 was more stimulatory than GHRH during low E(2) (P = 0.011) and high E(2) (P < 0.001). Stepwise forward-selection multivariate analysis revealed that computerized tomographic estimates of AVF explained 22% of the variability in GHRH action (P = 0.002), whereas age and E(2) together explained 60% of the variability in GHRP-2 drive (P < 0.001). These data establish that age, estrogen status, and AVF are triple covariates of continuous peptide-secretagogue drive of pulsatile GH secretion in women. Each factor must be controlled for to allow valid comparisons of GH-axis activity.
- Published
- 2009
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21. Ovarian stromal hyperthecosis: sonographic features and histologic associations.
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Brown DL, Henrichsen TL, Clayton AC, Hudson SB, Coddington CC 3rd, and Vella A
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Humans, Hyperplasia pathology, Middle Aged, Ovary diagnostic imaging, Ovary pathology, Stromal Cells diagnostic imaging, Stromal Cells pathology, Ultrasonography methods
- Abstract
Objective: Ovarian stromal hyperthecosis (SH) has variable clinical importance but can cause hyperandrogenism, particularly in premenopausal women. Sonography is often used to evaluate the ovaries of women with hyperandrogenism, but there is little published regarding the sonographic appearance of SH. The primary purpose of this study was to describe the sonographic features of SH., Methods: A computerized search of our institution's pathology and imaging databases from 1996 through 2007 was performed to identify patients with histologically proven SH who had pelvic sonography before surgery. Sonograms and histologic findings were reviewed in each case., Results: Twenty ovaries with SH were identified, occurring in 14 patients with a mean age of 59.8 years (range, 36-83 years). The SH was bilateral in 6 patients, unilateral in 6, and of uncertain laterality in 2 with a unilateral oophorectomy. Sonographic findings were as follows: 5 normal, 1 with a hemorrhagic cyst (later resolved) and otherwise normal, 3 enlarged but otherwise normal, 1 with a solid mass due to the nodular form of SH, 1 with a solid mass due to a fibroma, 2 with polycystic ovaries, and 7 not seen. Six of the 14 patients (43%) also had an ovarian fibrothecoma., Conclusions: Ovarian SH has variable sonographic features. Most commonly, the affected ovaries are either normal or slightly enlarged. A solid mass may infrequently be visible, and polycystic ovary syndrome changes may coexist with SH. A possible association of SH with fibrothecoma was also noted, which to our knowledge has not been previously reported.
- Published
- 2009
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- View/download PDF
22. Preimplantation genetic screening in a case of recurrent trisomy 21 offspring.
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Hudson SB, Coddington CC, Walker DL, Fredrickson JR, and Morbeck DE
- Subjects
- Adult, Down Syndrome genetics, Female, Humans, In Situ Hybridization, Fluorescence, Karyotyping, Live Birth, Pregnancy, Cryopreservation, Down Syndrome diagnosis, Embryo Transfer, Embryo, Mammalian, Genetic Testing, Preimplantation Diagnosis
- Abstract
Objective: To describe a unique case of recurrent aneuploidy and the use of preimplantation genetic screening (PGS)., Design: Case report., Setting: Midwest academic medical center., Patient(s): A 36-year-old woman with two trisomy 21 offspring., Intervention(s): Preimplantation genetic screening., Main Outcome Measure(s): Karyotype of embryos, liveborn eukaryotic infant., Result(s): Preimplantation genetic screening was performed on three cryopreserved embryos, followed by a two-embryo transfer yielding a eukaryotic infant., Conclusion(s): Preimplantation genetic screening may prove to be useful as a diagnostic tool to help ensure a euploid pregnancy when termination is not a viable option for a couple.
- Published
- 2009
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23. Magnetic resonance-guided focused ultrasound surgery.
- Author
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Hudson SB and Stewart EA
- Subjects
- Female, Humans, Patient Selection, Treatment Outcome, Leiomyoma therapy, Magnetic Resonance Imaging methods, Ultrasonic Therapy methods, Uterine Neoplasms therapy
- Abstract
Uterine leiomyomas pose a significant health issue to reproductive-age women. Many women desire uterine conservation, and previously safe and efficacious therapies have been limited. Magnetic resonance-guided focused ultrasound surgery is a new noninvasive therapy that has been proven to be both safe and efficacious in the treatment of fibroids.
- Published
- 2008
- Full Text
- View/download PDF
24. A light and electron microscopic study of ectopic tendon and ligament formation induced by bone morphogenetic protein-13 adenoviral gene therapy.
- Author
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Helm GA, Li JZ, Alden TD, Hudson SB, Beres EJ, Cunningham M, Mikkelsen MM, Pittman DD, Kerns KM, and Kallmes DF
- Subjects
- Animals, Bone Morphogenetic Proteins administration & dosage, Cell Differentiation drug effects, Injections, Intramuscular, Ligaments drug effects, Male, Microscopy, Electron, Models, Animal, Rats, Rats, Nude, Stem Cells drug effects, Stem Cells ultrastructure, Tendons drug effects, Adenoviridae, Bone Morphogenetic Proteins pharmacology, Choristoma pathology, Genetic Therapy, Ligaments anatomy & histology, Ligaments ultrastructure, Tendons anatomy & histology, Tendons ultrastructure
- Abstract
Object: Bone morphogenetic proteins (BMPs) are involved in the growth and development of many tissues, but it is their role in skeletal development and their unique ability to induce ectopic and orthotopic osteogenesis that have attracted the greatest interest. Expression of the BMP-13 gene is predominantly localized to hypertrophic chondrocytes in regions of endochondral bone formation during development, as well as in mature articular cartilage in the adult. In addition, the application of BMP-13 on a collagen carrier induces neotendon/neoligament formation when delivered subcutaneously or intramuscularly in rodents. The aim of the present study was to determine the histological and ultrastructural changes that occur after the intramuscular injection of a first-generation BMP-13 adenoviral vector., Methods: Athymic nude rats were injected with 3.75 x 10(10) plaque-forming units of adenovirus (Ad)-BMP-13 or Ad-beta-galactosidase in the thigh musculature, and the region was examined using light and electron microscopy at various time points between 2 days and 100 days postinjection. As early as 2 days after injection of Ad-BMP-13, progenitor cells were observed infiltrating between the transduced muscle fibers. These cells subsequently proliferated, differentiated, and secreted large amounts of collagenous extracellular matrix. By 100 days postinjection, the treated tissue displayed the histological and ultrastructural appearance of neotendon/neoligament, which was clearly demarcated from the surrounding muscle. Small foci of bone and fibrocartilage were also seen within the treated tissue. A short-term bromodeoxyuridine study also demonstrated rapid mesenchymal cell proliferation at the Ad-BMP-13 injection site as early as 48 hours postinjection. At all time points, the control AD-beta-gal injection sites were found to contain only normal muscle, without evidence of inflammation or mesenchymal cell proliferation., Conclusions: The results of this study indicate that in the future the use of the BMP-13 gene may have therapeutic utility for the healing of tendon and ligament tears and avulsion injuries.
- Published
- 2001
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25. Use of bone morphogenetic protein-9 gene therapy to induce spinal arthrodesis in the rodent.
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Helm GA, Alden TD, Beres EJ, Hudson SB, Das S, Engh JA, Pittman DD, Kerns KM, and Kallmes DF
- Subjects
- Adenoviridae genetics, Animals, Humans, Image Processing, Computer-Assisted, Lumbar Vertebrae pathology, Male, Rats, Rats, Nude, Tomography, X-Ray Computed, Bone Morphogenetic Proteins genetics, Bone Regeneration genetics, Genetic Therapy, Spinal Fusion
- Abstract
Object: Bone morphogenetic proteins (BMPs) have been shown to have significant osteoinductive activity in numerous in vitro and in vivo assay systems, and BMP-2 and BMP-7 are currently being evaluated in human clinical studies. In the spinal region, BMPs have been shown to promote spinal arthrodesis at a higher rate than autologous bone alone. The delivery of BMPs via direct or ex vivo gene therapy techniques is also currently being evaluated and has shown promise in several mammalian models. The present study was designed to evaluate the efficacy of the use of direct, percutaneous BMP-9 adenoviral gene therapy to promote spinal fusion in the rodent., Methods: Each animal was injected with 7.5x10(8) pfu of a BMP-9 adenoviral vector in the lumbar paraspinal musculature and allowed to survive 16 weeks. Computerized tomography studies and histological analysis demonstrated massive bone induction at the injection sites, clearly leading to solid spinal arthrodesis, without evidence of pseudarthroses, nerve root compression, or systemic side effects., Conclusions: The results of this study strongly support the advancement of BMP gene therapy techniques toward clinical use.
- Published
- 2000
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26. Bovine type I collagen as an endovascular stent-graft material: biocompatibility study in rabbits.
- Author
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Cloft HJ, Kallmes DF, Lin HB, Li ST, Marx WF, Hudson SB, Helm GA, Lopes MB, McGraw JK, Dion JE, and Jensen ME
- Subjects
- Alloys chemistry, Animals, Aorta, Abdominal diagnostic imaging, Aorta, Abdominal pathology, Aorta, Abdominal surgery, Blood Vessel Prosthesis Implantation, Cattle, Cell Adhesion, Endothelium, Vascular pathology, Erythrocytes pathology, Fibroblasts pathology, Follow-Up Studies, Humans, Leukocytes pathology, Materials Testing, Rabbits, Radiography, Surface Properties, Tunica Intima pathology, Vascular Patency, Biocompatible Materials chemistry, Blood Vessel Prosthesis, Collagen chemistry, Collagen ultrastructure, Prosthesis Design, Stents
- Abstract
Purpose: To study the biocompatibility of a bovine type I collagen preparation as a material for small-vessel stent-grafts in rabbits., Materials and Methods: A composite nitinol-collagen endovascular stent-graft with a 4-mm inner diameter was deployed in the abdominal aorta in nine rabbits. Angiography was performed, and the rabbits were sacrificed at 1, 2, and 7 days and at 1 and 3 months. The portion of the aorta containing the stent-graft was excised and was histologically evaluated., Results: All stent-grafts were patent at all time points. On days 1, 2, and 7 after implantation, scattered red and white blood cells adhered to the stent-graft. At 1 month, the stent-graft was endothelialized and was infiltrated with fibroblasts that deposited collagen within the interstices of the implanted collagen material. At 3 months, there was additional collagen deposition within the interstices of the stent-graft that did not narrow the lumen of the stent-grafts., Conclusion: Type I collagen as a intravascular stent-graft material is biocompatible for at least 3 months in rabbits. It is rapidly endothelialized and does not cause reactive stenosis. As a versatile and biocompatible polymer, collagen is potentially useful in the construction of endovascular stent-grafts for use in human arteries.
- Published
- 2000
- Full Text
- View/download PDF
27. The use of bone morphogenetic protein gene therapy in craniofacial bone repair.
- Author
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Alden TD, Beres EJ, Laurent JS, Engh JA, Das S, London SD, Jane JA Jr, Hudson SB, and Helm GA
- Subjects
- Animals, Bone Marrow diagnostic imaging, Bone Marrow pathology, Bone Morphogenetic Protein 2, Bone Morphogenetic Proteins therapeutic use, Bone Regeneration, Cytomegalovirus genetics, Follow-Up Studies, Genetic Vectors, Growth Differentiation Factor 2, Image Processing, Computer-Assisted, Mandible diagnostic imaging, Mandible pathology, Mandibular Diseases diagnostic imaging, Mandibular Diseases pathology, Osteogenesis, Osteoporosis therapy, Rats, Rats, Nude, Spinal Fusion, Tomography, X-Ray Computed, Transforming Growth Factor beta therapeutic use, Wound Healing, beta-Galactosidase genetics, Bone Morphogenetic Proteins genetics, Genetic Therapy, Mandibular Diseases therapy, Transforming Growth Factor beta genetics
- Abstract
Bone morphogenetic proteins (BMPs) are capable of inducing endochondral bone formation when applied on biologic carriers in numerous mammalian in vivo assay systems. Bone morphogenetic protein gene therapy is also currently being developed to promote osteogenesis for clinical indications such as spinal fusions, craniofacial bone loss, and osteoporosis. In this study, critical-sized mandibular defects were treated with a control adenoviral vector (Ad-beta-gal), a BMP-2 adenoviral vector (Ad-BMP-2), or a BMP-9 adenoviral vector (Ad-BMP-9). Gross tissue examination, radiographic analysis, and histologic analysis demonstrated significant bony healing in the BMP treated groups compared to controls. Osteogenesis was limited to the bony defect, without extension into the surrounding soft tissues. The study suggests that with further development, BMP gene therapy may be potentially useful for repair of bony defects in the craniofacial region.
- Published
- 2000
- Full Text
- View/download PDF
28. Histologic evaluation of platinum coil embolization in an aneurysm model in rabbits.
- Author
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Kallmes DF, Helm GA, Hudson SB, Altes TA, Do HM, Mandell JW, and Cloft HJ
- Subjects
- Animals, Carotid Artery Diseases pathology, Carotid Artery, Common diagnostic imaging, Carotid Artery, Common pathology, Embolization, Therapeutic methods, Intracranial Aneurysm diagnostic imaging, Intracranial Aneurysm pathology, Platinum, Rabbits, Radiography, Carotid Artery Diseases therapy, Embolization, Therapeutic instrumentation, Intracranial Aneurysm therapy
- Abstract
Purpose: To characterize the histologic response to platinum coil embolization by using a rabbit aneurysm model., Materials and Methods: Saccular aneurysms were created in New Zealand White rabbits by using vessel ligation with intraluminal elastase incubation. Aneurysms were subsequently embolized by using platinum coils. Subjects were sacrificed at various intervals up to 12 weeks following coil embolization. The aneurysm cavities and adjacent vessels were embedded in methylmethacrylate, were sectioned, and were stained for histologic examination., Results: Two weeks following coil implantation, aneurysms were filled predominantly with unorganized thrombus. Six weeks following coil implantation, histologic features included complete filling of the aneurysm lumen with either prominent laminated but unorganized thrombus or areas of unorganized thrombus interspersed among areas of cellular infiltration. At 12 weeks following coil implantation, aneurysms were filled with the loosely packed, disordered cells contained within the extracellular matrix. Fibrosis or smooth muscle cell infiltration was not present in any of the 6- or 12-week samples., Conclusion: Platinum coils placed into experimental saccular aneurysms in New Zealand White rabbits failed to elicit a fibrotic response. This model can be used for the testing of biologic modifications of platinum coils aimed at increasing intra-aneurysmal fibrosis.
- Published
- 1999
- Full Text
- View/download PDF
29. Endovascular creation of an in vivo bifurcation aneurysm model in rabbits.
- Author
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Cloft HJ, Altes TA, Marx WF, Raible RJ, Hudson SB, Helm GA, Mandell JW, Jensen ME, Dion JE, and Kallmes DF
- Subjects
- Animals, Carotid Artery Diseases diagnostic imaging, Carotid Artery Diseases etiology, Carotid Artery Diseases pathology, Carotid Artery, Common, Catheterization, Pancreatic Elastase, Radiography, Disease Models, Animal, Intracranial Aneurysm diagnostic imaging, Intracranial Aneurysm etiology, Intracranial Aneurysm pathology, Rabbits
- Abstract
Purpose: To develop a rabbit model of an intracranial bifurcation aneurysm to test new endovascular therapies., Materials and Methods: An experimental aneurysm model was created in rabbits by means of endovascular balloon occlusion of the left common carotid artery, which created an aneurysm at the bifurcation formed by the aortic arch and the brachiocephalic trunk. A total of 18 aneurysms were created. In eight rabbits, the aneurysms were incubated with intraluminal elastase to induce degeneration of the elastic laminae. The animals were followed up with angiography for as long as 3 months. The animals were sacrificed at various times, and histologic evaluation of the aneurysm was performed., Results: Ten aneurysms created without elastase infusion were all very small or completely closed at 1-3 months. Six aneurysms created with elastase infusion had long-term patency (two were patent at 1 month and four, at 3 months). The elastase aneurysms had a mean width of 3 mm (range, 2-3.5 mm) and a mean length of 5 mm (range, 3-7 mm). Histologic evaluation revealed destruction of the normal elastin layers, which allowed the artery to become aneurysmal., Conclusion: This aneurysm model re-created the hemodynamic forces and size of human cerebral bifurcation aneurysms and maintained the integrity of the endothelium. The creation of the aneurysms was rapid, reliable, and reproducible.
- Published
- 1999
- Full Text
- View/download PDF
30. In vivo endochondral bone formation using a bone morphogenetic protein 2 adenoviral vector.
- Author
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Alden TD, Pittman DD, Hankins GR, Beres EJ, Engh JA, Das S, Hudson SB, Kerns KM, Kallmes DF, and Helm GA
- Subjects
- Adenoviridae genetics, Animals, Bone Morphogenetic Protein 2, Bone and Bones diagnostic imaging, Cell Line, Gene Expression, Genetic Vectors, Immunohistochemistry, Rats, Rats, Nude, Rats, Sprague-Dawley, Tomography, X-Ray Computed, Bone Development, Bone Morphogenetic Proteins genetics, Gene Transfer Techniques, Transforming Growth Factor beta
- Abstract
Bone morphogenetic proteins (BMPs) are polypeptides that induce ectopic bone formation in standard rat in vivo assay systems. Previous studies have demonstrated the clinical utility of these proteins in spinal fusion, fracture healing, and prosthetic joint stabilization. Gene therapy is also a theoretically attractive technique to express BMPs clinically, since long-term, regulatable gene expression and systemic delivery with tissue-specific expression may be possible in future. This study was performed to determine whether an adenoviral vector containing the BMP-2 gene can be used to express BMP-2 in vitro and promote endochondral bone formation in vivo. In vitro, U87 MG cells transduced per cell with 20 MOI of an adenoviral construct containing the BMP-2 gene under the control of the universal CMV promoter (Ad-BMP-2) showed positive antibody staining for the BMP-2 protein at posttransfection day 2. The synthesis and secretion of active BMP-2 into the conditioned medium of Ad-BMP-2-transduced 293 cells were confirmed by Western blot analysis and the induction of alkaline phosphatase activity in a W-20 stromal cell assay. In vivo, Sprague-Dawley rats and athymic nude rats were injected with Ad-BMP-2 in the thigh musculature and were sacrificed on day 3, 6, 9, 12, 16, 21, 60, and 110 for histological analysis. The Sprague-Dawley rats showed evidence of acute inflammation, without ectopic bone formation, at the injection sites. In the athymic nude rats, BMP-2 gene therapy induced mesenchymal stem cell chemotaxis and proliferation, with subsequent differentiation to chondrocytes. The chondrocytes secreted a cartilaginous matrix, which then mineralized and was replaced by mature bone. This study demonstrates that a BMP-2 adenoviral vector can be utilized to produce BMP-2 by striated muscle cells in athymic nude rats, leading to endochondral bone formation. However, in immunocompetent animals the endochondral response is attenuated, secondary to the massive immune response elicited by the first-generation adenoviral construct.
- Published
- 1999
- Full Text
- View/download PDF
31. Hemoglobin penetration in the wall of the rabbit basilar artery after subarachnoid hemorrhage and intracisternal hemoglobin injection.
- Author
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Foley PL, Kassell NF, Hudson SB, and Lee KS
- Subjects
- Animals, Fluorescent Antibody Technique, Humans, Immunoblotting, Mice, Muscle, Smooth, Vascular pathology, Rabbits, Vasoconstriction, Basilar Artery pathology, Cisterna Magna pathology, Hemoglobins metabolism, Ischemic Attack, Transient pathology, Oxyhemoglobins metabolism, Subarachnoid Hemorrhage pathology
- Abstract
The ability of hemoglobin (Hb) to penetrate the basilar arterial wall in vivo after experimental subarachnoid hemorrhage was examined using immunohistochemistry. The distribution of anti-Hb antibodies in rabbit basilar artery was studied following the injection of autologous blood in the cisterna magna. Vessels removed two or four days after subarachnoid hemorrhage exhibited varying degrees of vasospasm, and exhibited Hb immuno-fluorescence throughout the vessel wall. Hemoglobin immunofluorescence was most conspicuous in the adventitia but was also seen in the smooth muscle and endothelial cell layers in 7 of 10 animals. The degree of vasoconstriction correlated with the total amount of Hb-fluorescence present in the vessel wall. When Hb solution alone was injected into the subarachnoid space, vasoconstriction was evident but penetration into the vascular layers was not as extensive as that observed after injection of autologous blood. These findings demonstrate that Hb is able to penetrate through the arterial wall after subarachnoid hemorrhage. The results provide direct support for the hypothesis that Hb-induced changes in smooth muscle and/or endothelial function can contribute to the pathogenesis of vasospasm.
- Published
- 1993
- Full Text
- View/download PDF
32. Immunohistochemical demonstration of transient increase in prostaglandin F2-alpha after recirculation in global ischemic rat brains.
- Author
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Ogawa H, Kassell NF, Sasaki T, Hongo K, Tsukahara T, Hudson SB, Asban GI, and Tuan HL
- Subjects
- Animals, Cerebellum metabolism, Cerebellum physiopathology, Hippocampus metabolism, Hippocampus physiopathology, Immunohistochemistry, Ischemic Attack, Transient physiopathology, Male, Rats, Rats, Inbred Strains, Time Factors, Cerebrovascular Circulation, Dinoprost metabolism, Ischemic Attack, Transient metabolism
- Abstract
The changes in prostaglandin F2-alpha (PG F2 alpha) staining over 3 days of recirculation in both fore- and hindbrains were studied. Five minutes of global ischemia was produced in 24 rats by Pulsinelli's method with hypotension around 50 mm Hg of mean arterial blood pressure. Eight rats (including three pretreated with indomethacin) were recirculated for 5 min, three for 1 h, five for 2 h and five for 3 days. Five normal rats without occlusion of vessels served as controls. The brains were snap frozen. Ten-micrometer cryosections were stained for PG F2 alpha by the indirect immunofluorescence method after fixation in carbodiimide and in Zamboni's solution. Positive staining for PG F2 alpha was noted in pial vessels in all normal and ischemic rats. Recirculated rats revealed the strongest reaction at 5 min after recirculation in blood vessels and in neuronal cytoplasm (especially in hippocampi and in Purkinje cells). The intensity of staining was markedly reduced after 1 h. Rats pretreated with indomethacin showed less increase in staining. The above results indicate that recirculation after ischemia produces a transient increase in PG F2 alpha in blood vessels and neurons of both fore- and hindbrains.
- Published
- 1988
- Full Text
- View/download PDF
33. Phonological code activation during listening.
- Author
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Hudson SB and Tanenhaus MK
- Subjects
- Attention, Humans, Mental Recall, Psycholinguistics, Semantics, Phonetics, Speech Perception
- Abstract
Rhyme priming to visually dissimilar rhymes (e.g., eight-late) was used in a lexical decision task to investigate the access and maintenance of speech-based codes in sentence comprehension. One member of the rhyme pair was embedded in a sentence and the other was presented visually for lexical decision. Rhyme priming obtained when the prime and target were separated by four but not by seven intervening words, suggesting that the phonological code for the word was initially accessed and then rapidly decayed.
- Published
- 1985
- Full Text
- View/download PDF
34. Repeated epidural anesthesia for extracorporeal shock-wave lithotripsy is unreliable.
- Author
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Korbon GA, Lynch C 3rd, Arnold WP, Ross WT, and Hudson SB
- Subjects
- Epidural Space, Epinephrine, Humans, Injections, Epidural adverse effects, Kidney Calculi therapy, Lidocaine, Middle Aged, Prospective Studies, Anesthesia, Epidural adverse effects, Lithotripsy
- Published
- 1987
35. Immunohistochemically demonstrated increase of prostaglandin F2-alpha in neurons after reoxygenation in anoxic rats.
- Author
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Ogawa H, Kassell NF, Sasaki T, Hongo K, Tsukahara T, Hudson SB, Asban GI, Tuan HL, and Torner JC
- Subjects
- Animals, Blood Pressure, Decerebrate State, Fluorescent Antibody Technique, In Vitro Techniques, Male, Rats, Brain metabolism, Dinoprost biosynthesis, Hypoxia metabolism
- Abstract
Immunohistochemical staining for prostaglandin F2-alpha (PG F2 alpha) was conducted to identify PG F2 alpha synthesizing or binding sites in anoxic rat brains. Anoxia was produced in 22 rats to lower the arterial oxygen tension (PaO2) to 21 +/- 4 mmHg by ventilation with a 95% nitrogen and 5% carbon dioxide gas mixture. In 8 animals anoxia was continued for 30 sec, and in 14 rats for 3 min. Prior to decapitation, 5 animals in the 30-sec anoxia group and 8 rats in the 3-min anoxia group were reoxygenated for 5 min, while the remaining 9 were not. Five-min reoxygenation returned the PaO2 to 106 +/- 7. Three non-reoxygenated and 3 reoxygenated rats, all pretreated with indomethacin, and 5 normal rats served as controls. The brains were snap-frozen. The cryosections were stained by the indirect immunofluorescence method. PG F2 alpha was noted mainly in pial vessels in all normal rats. All reoxygenated rats showed a positive reaction not only in blood vessels, but also in neurons, particularly hippocampal neurons and Purkinje cells. The staining of the above neurons was noted to be less in non-reoxygenated rats. The stronger staining was observed in rats reoxygenated after 3-min anoxia than 30-sec anoxia. The indomethacin-pretreated rats showed almost no increase in staining intensity. The above results indicate that reoxygenation after anoxia results in an increase of PG F2 alpha in neurons of both cerebrum and cerebellum.
- Published
- 1988
- Full Text
- View/download PDF
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