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Bell KL, Campos M, Hoffmann BD, Encinas-Viso F, Hunter GC, Webber BL. Environmental DNA methods for biosecurity and invasion biology in terrestrial ecosystems: Progress, pitfalls, and prospects. Sci Total Environ 2024; 926:171810. [PMID: 38513869 DOI: 10.1016/j.scitotenv.2024.171810] [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: 12/21/2023] [Revised: 03/13/2024] [Accepted: 03/16/2024] [Indexed: 03/23/2024]
Abstract
Analysis of environmental DNA (eDNA) enables indirect detection of species without the need to directly observe and sample them. For biosecurity and invasion biology, eDNA-based methods are useful to address biological invasions at all phases, from detecting arrivals to confirming eradication of past invasions. We conducted a systematic review of the literature and found that in biosecurity and invasion biology, eDNA has primarily been used to detect new incursions and monitor spread in marine and freshwater ecosystems, with much slower uptake in terrestrial ecosystems, reflecting a broader trend common to the usage of eDNA tools. In terrestrial ecosystems, eDNA research has mostly focussed on the use of eDNA metabarcoding to characterise biodiversity, rather than targeting biosecurity threats or non-native populations. We discuss how eDNA-based methods are being applied to terrestrial ecosystems for biosecurity and managing non-native populations at each phase of the invasion continuum: transport, introduction, establishment, and spread; across different management options: containment, control, and eradication; and for detecting the impact of non-native organisms. Finally, we address some of the current technical issues and caveats of eDNA-based methods, particularly for terrestrial ecosystems, and how these might be solved. As eDNA-based methods improve, they will play an increasingly important role in the early detection and adaptive management of biological invasions, and the implementation of effective biosecurity controls.
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Affiliation(s)
- Karen L Bell
- CSIRO Health & Biosecurity, Floreat, Western Australia 6014, Australia; School of Biological Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia.
| | - Mariana Campos
- CSIRO Health & Biosecurity, Floreat, Western Australia 6014, Australia; Harry Butler Institute, Murdoch University, Murdoch, Western Australia 6150, Australia
| | | | - Francisco Encinas-Viso
- CSIRO Centre of Australian National Biodiversity Research, Black Mountain, Australian Capital Territory 2601, Australia
| | - Gavin C Hunter
- CSIRO Health & Biosecurity, Black Mountain, Australian Capital Territory 2601, Australia
| | - Bruce L Webber
- CSIRO Health & Biosecurity, Floreat, Western Australia 6014, Australia; School of Biological Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
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2
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Bell KL, Turo KJ, Lowe A, Nota K, Keller A, Encinas‐Viso F, Parducci L, Richardson RT, Leggett RM, Brosi BJ, Burgess KS, Suyama Y, de Vere N. Plants, pollinators and their interactions under global ecological change: The role of pollen DNA metabarcoding. Mol Ecol 2023; 32:6345-6362. [PMID: 36086900 PMCID: PMC10947134 DOI: 10.1111/mec.16689] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 08/18/2022] [Accepted: 08/30/2022] [Indexed: 11/28/2022]
Abstract
Anthropogenic activities are triggering global changes in the environment, causing entire communities of plants, pollinators and their interactions to restructure, and ultimately leading to species declines. To understand the mechanisms behind community shifts and declines, as well as monitoring and managing impacts, a global effort must be made to characterize plant-pollinator communities in detail, across different habitat types, latitudes, elevations, and levels and types of disturbances. Generating data of this scale will only be feasible with rapid, high-throughput methods. Pollen DNA metabarcoding provides advantages in throughput, efficiency and taxonomic resolution over traditional methods, such as microscopic pollen identification and visual observation of plant-pollinator interactions. This makes it ideal for understanding complex ecological networks and their responses to change. Pollen DNA metabarcoding is currently being applied to assess plant-pollinator interactions, survey ecosystem change and model the spatiotemporal distribution of allergenic pollen. Where samples are available from past collections, pollen DNA metabarcoding has been used to compare contemporary and past ecosystems. New avenues of research are possible with the expansion of pollen DNA metabarcoding to intraspecific identification, analysis of DNA in ancient pollen samples, and increased use of museum and herbarium specimens. Ongoing developments in sequencing technologies can accelerate progress towards these goals. Global ecological change is happening rapidly, and we anticipate that high-throughput methods such as pollen DNA metabarcoding are critical for understanding the evolutionary and ecological processes that support biodiversity, and predicting and responding to the impacts of change.
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Affiliation(s)
- Karen L. Bell
- CSIRO Health & Biosecurity and CSIRO Land & WaterFloreatWAAustralia
- School of Biological SciencesUniversity of Western AustraliaCrawleyWAAustralia
| | - Katherine J. Turo
- Department of Ecology, Evolution, and Natural ResourcesRutgers UniversityNew BrunswickNew JerseyUSA
| | | | - Kevin Nota
- Department of Ecology and GeneticsEvolutionary Biology Centre, Uppsala UniversityUppsalaSweden
| | - Alexander Keller
- Organismic and Cellular Networks, Faculty of BiologyBiocenter, Ludwig‐Maximilians‐Universität MünchenPlaneggGermany
| | - Francisco Encinas‐Viso
- Centre for Australian National Biodiversity ResearchCSIROBlack MountainAustralian Capital TerritoryAustralia
| | - Laura Parducci
- Department of Ecology and GeneticsEvolutionary Biology Centre, Uppsala UniversityUppsalaSweden
- Department of Environmental BiologySapienza University of RomeRomeItaly
| | - Rodney T. Richardson
- Appalachian LaboratoryUniversity of Maryland Center for Environmental ScienceFrostburgMarylandUSA
| | | | - Berry J. Brosi
- Department of BiologyUniversity of WashingtonSeattleWashingtonUSA
| | - Kevin S. Burgess
- Department of BiologyCollege of Letters and Sciences, Columbus State University, University System of GeorgiaAtlantaGeorgiaUSA
| | - Yoshihisa Suyama
- Field Science CenterGraduate School of Agricultural Science, Tohoku UniversityOsakiMiyagiJapan
| | - Natasha de Vere
- Natural History Museum of DenmarkUniversity of CopenhagenCopenhagenDenmark
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Chesters D, Liu X, Bell KL, Orr MC, Xie T, Zhou Q, Zhu C. An integrative bioinformatics pipeline shows that honeybee-associated microbiomes are driven primarily by pollen composition. Insect Sci 2023; 30:555-568. [PMID: 36001735 DOI: 10.1111/1744-7917.13104] [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: 02/08/2022] [Revised: 07/11/2022] [Accepted: 07/24/2022] [Indexed: 06/15/2023]
Abstract
The microbiomes associated with bee nests influence colony health through various mechanisms, although it is not yet clear how honeybee congeners differ in microbiome assembly processes, in particular the degrees to which floral visitations and the environment contribute to different aspects of diversity. We used DNA metabarcoding to sequence bacterial 16S rRNA from honey and stored pollen from nests of 4 honeybee species (Apis cerana, A. dorsata, A. florea, and A. laboriosa) sampled throughout Yunnan, China, a global biodiversity hotspot. We developed a computational pipeline integrating multiple databases for quantifying key facets of diversity, including compositional, taxonomic, phylogenetic, and functional ones. Further, we assessed candidate drivers of observed microbiome dissimilarity, particularly differences in floral visitations, habitat disturbance, and other key environmental variables. Analyses revealed that microbiome alpha diversity was broadly equivalent across the study sites and between bee species, apart from functional diversity which was very low in nests of the reclusive A. laboriosa. Turnover in microbiome composition across Yunnan was driven predominantly by pollen composition. Human disturbance negatively impacted both compositional and phylogenetic alpha diversity of nest microbiomes, but did not correlate with microbial turnover. We herein make progress in understanding microbiome diversity associated with key pollinators in a biodiversity hotspot, and provide a model for the use of a comprehensive informatics framework in assessing pattern and drivers of diversity, which enables the inclusion of explanatory variables both subtly and fundamentally different and enables elucidation of emergent or unexpected drivers.
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Affiliation(s)
- Douglas Chesters
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- International College, University of Chinese Academy of Sciences, Beijing, China
| | - Xiuwei Liu
- Institute of Agro-Products Processing, Yunnan Province Academy of Agricultural Science, Kunming, China
| | - Karen L Bell
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- CSIRO Health & Biosecurity, Floreat, WA, Australia
| | - Michael C Orr
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- International College, University of Chinese Academy of Sciences, Beijing, China
| | - Tingting Xie
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, Anhui Normal University, Wuhu, Anhui Province, China
| | - Qingsong Zhou
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Chaodong Zhu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- International College, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Biological Sciences, University of Chinese Academy of Sciences, Beijing, China
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Grill J, Berkness T, Carrillo MC, Snyder HM, Aisen P, Sperling RA, Petersen RC, Aggarwal NT, Bell KL, Burns JM, Donohue MC, Dodge HH, Espeland MA, Gillen DL, Geldmacher DS, Heidebrink JL, Jicha GA, Olichney JM, Rafii MS, Rentz DM, Salloway SP, Sethuraman G, Smith AG, Raman R. The Institute on Methods and Protocols for Advancement of Clinical Trials for ADRD (IMPACT‐AD): An update after two years of conduct. Alzheimers Dement 2022. [DOI: 10.1002/alz.064617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Joshua Grill
- Institute for Memory Impairments and Neurological Disorders University of California Irvine Irvine CA USA
| | - Tyler Berkness
- Alzheimer’s Therapeutic Research Institute University of Southern California San Diego CA USA
| | | | | | - Paul Aisen
- Alzheimer’s Therapeutic Research Institute University of Southern California San Diego CA USA
| | - Reisa A. Sperling
- Brigham and Women’s Hospital Harvard Medical School Boston MA USA
- Massachusetts General Hospital Brigham and Women’s Hospital Harvard Medical School Boston MA USA
| | | | - Neelum T. Aggarwal
- Rush Alzheimer’s Disease Center, Department of Neurological Sciences Chicago IL USA
| | - Karen L. Bell
- Department of Neurology Columbia University Vagelos College of Physicians and Surgeons New York NY USA
| | - Jeffrey M. Burns
- University of Kansas Alzheimer’s Disease Research Center Fairway KS USA
| | - Michael C. Donohue
- Alzheimer’s Therapeutic Research Institute Keck School of Medicine University of Southern California San Diego CA USA
| | - Hiroko H Dodge
- Layton Aging & Alzheimer’s Disease Center, Oregon Health & Science University Portland OR USA
| | | | | | | | | | | | | | - Michael S Rafii
- Alzheimer’s Therapeutic Research Institute University of Southern California San Diego CA USA
| | - Dorene M. Rentz
- Brigham and Women’s Hospital Harvard Medical School Boston MA USA
- Massachusetts General Hospital Harvard Medical School Boston MA USA
| | - Stephen P. Salloway
- Alpert Medical School of Brown University Providence RI USA
- Butler Hospital Providence RI USA
| | - Gopalan Sethuraman
- Alzheimer’s Therapeutic Research Institute University of Southern California San Diego CA USA
| | | | - Rema Raman
- Alzheimer’s Therapeutic Research Institute University of Southern California San Diego CA USA
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Byrne D, Scheben A, Scott JK, Webber BL, Batchelor KL, Severn-Ellis AA, Gooden B, Bell KL. Genomics reveals the history of a complex plant invasion and improves the management of a biological invasion from the South African-Australian biotic exchange. Ecol Evol 2022; 12:e9179. [PMID: 36016815 PMCID: PMC9396708 DOI: 10.1002/ece3.9179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 11/10/2022] Open
Abstract
Many plants exchanged in the global redistribution of species in the last 200 years, particularly between South Africa and Australia, have become threatening invasive species in their introduced range. Refining our understanding of the genetic diversity and population structure of native and alien populations, introduction pathways, propagule pressure, naturalization, and initial spread, can transform the effectiveness of management and prevention of further introductions. We used 20,221 single nucleotide polymorphisms to reconstruct the invasion of a coastal shrub, Chrysanthemoides monilifera ssp. rotundata (bitou bush) from South Africa, into eastern Australia (EAU), and Western Australia (WAU). We determined genetic diversity and population structure across the native and introduced ranges and compared hypothesized invasion scenarios using Bayesian modeling. We detected considerable genetic structure in the native range, as well as differentiation between populations in the native and introduced range. Phylogenetic analysis showed the introduced samples to be most closely related to the southern‐most native populations, although Bayesian analysis inferred introduction from a ghost population. We detected strong genetic bottlenecks during the founding of both the EAU and WAU populations. It is likely that the WAU population was introduced from EAU, possibly involving an unsampled ghost population. The number of private alleles and polymorphic SNPs successively decreased from South Africa to EAU to WAU, although heterozygosity remained high. That bitou bush remains an invasion threat in EAU, despite reduced genetic diversity, provides a cautionary biosecurity message regarding the risk of introduction of potentially invasive species via shipping routes.
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Affiliation(s)
- Dennis Byrne
- CSIRO Health & Biosecurity Floreat Western Australia Australia.,School of Biological Sciences University of Western Australia Crawley Western Australia Australia
| | - Armin Scheben
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia.,Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory Cold Spring, Harbor New York USA
| | - John K Scott
- CSIRO Health & Biosecurity Floreat Western Australia Australia.,School of Biological Sciences University of Western Australia Crawley Western Australia Australia
| | - Bruce L Webber
- CSIRO Health & Biosecurity Floreat Western Australia Australia.,School of Biological Sciences University of Western Australia Crawley Western Australia Australia.,Western Australian Biodiversity Science Institute Perth Western Australia Australia
| | | | - Anita A Severn-Ellis
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
| | - Ben Gooden
- CSIRO Health and Biosecurity Canberra Australian Capital Territory Australia.,Centre for Sustainable Ecosystem Solutions School of Earth, Atmospheric and Life Sciences, University of Wollongong Wollongong New South Wales Australia
| | - Karen L Bell
- CSIRO Health & Biosecurity Floreat Western Australia Australia.,School of Biological Sciences University of Western Australia Crawley Western Australia Australia
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Bidelman GM, Chow R, Noly-Gandon A, Ryan JD, Bell KL, Rizzi R, Alain C. Transcranial Direct Current Stimulation Combined With Listening to Preferred Music Alters Cortical Speech Processing in Older Adults. Front Neurosci 2022; 16:884130. [PMID: 35873829 PMCID: PMC9298650 DOI: 10.3389/fnins.2022.884130] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 06/17/2022] [Indexed: 11/13/2022] Open
Abstract
Emerging evidence suggests transcranial direct current stimulation (tDCS) can improve cognitive performance in older adults. Similarly, music listening may improve arousal and stimulate subsequent performance on memory-related tasks. We examined the synergistic effects of tDCS paired with music listening on auditory neurobehavioral measures to investigate causal evidence of short-term plasticity in speech processing among older adults. In a randomized sham-controlled crossover study, we measured how combined anodal tDCS over dorsolateral prefrontal cortex (DLPFC) paired with listening to autobiographically salient music alters neural speech processing in older adults compared to either music listening (sham stimulation) or tDCS alone. EEG assays included both frequency-following responses (FFRs) and auditory event-related potentials (ERPs) to trace neuromodulation-related changes at brainstem and cortical levels. Relative to music without tDCS (sham), we found tDCS alone (without music) modulates the early cortical neural encoding of speech in the time frame of ∼100-150 ms. Whereas tDCS by itself appeared to largely produce suppressive effects (i.e., reducing ERP amplitude), concurrent music with tDCS restored responses to those of the music+sham levels. However, the interpretation of this effect is somewhat ambiguous as this neural modulation could be attributable to a true effect of tDCS or presence/absence music. Still, the combined benefit of tDCS+music (above tDCS alone) was correlated with listeners' education level suggesting the benefit of neurostimulation paired with music might depend on listener demographics. tDCS changes in speech-FFRs were not observed with DLPFC stimulation. Improvements in working memory pre to post session were also associated with better speech-in-noise listening skills. Our findings provide new causal evidence that combined tDCS+music relative to tDCS-alone (i) modulates the early (100-150 ms) cortical encoding of speech and (ii) improves working memory, a cognitive skill which may indirectly bolster noise-degraded speech perception in older listeners.
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Affiliation(s)
- Gavin M. Bidelman
- Department of Speech, Language and Hearing Sciences, Indiana University Bloomington, Bloomington, IN, United States,School of Communication Sciences and Disorders, The University of Memphis, Memphis, TN, United States,*Correspondence: Gavin M. Bidelman,
| | - Ricky Chow
- Rotman Research Institute, Baycrest Centre, Toronto, ON, Canada
| | | | - Jennifer D. Ryan
- Rotman Research Institute, Baycrest Centre, Toronto, ON, Canada,Department of Psychology, University of Toronto, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Karen L. Bell
- Department of Audiology, San José State University, San Jose, CA, United States
| | - Rose Rizzi
- Department of Speech, Language and Hearing Sciences, Indiana University Bloomington, Bloomington, IN, United States,School of Communication Sciences and Disorders, The University of Memphis, Memphis, TN, United States
| | - Claude Alain
- Rotman Research Institute, Baycrest Centre, Toronto, ON, Canada,Department of Psychology, University of Toronto, Toronto, ON, Canada,Institute of Medical Science, University of Toronto, Toronto, ON, Canada,Music and Health Science Research Collaboratory, University of Toronto, Toronto, ON, Canada
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Bradford M, Venz M, Bell KL, Hogan L, Smith GC, Eby P, Eyre TJ, McKeown A, Vanderduys E, MacDonald S, Westcott D. The diet of a specialist nectarivore in Australia: The little red flying‐fox (
Pteropus scapulatus
, Pteropodidae). AUSTRAL ECOL 2022. [DOI: 10.1111/aec.13143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Melanie Venz
- QLD Herbarium QLD Department of Environment and Science Toowong Queensland 4066 Australia
| | - Karen L. Bell
- CSIRO Health & Biosecurity Floreat Western Australia Australia
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
| | - Luke Hogan
- QLD Herbarium QLD Department of Environment and Science Toowong Queensland 4066 Australia
| | - Geoffrey C. Smith
- QLD Herbarium QLD Department of Environment and Science Toowong Queensland 4066 Australia
| | - Peggy Eby
- Centre for Ecosystem Science University of New South Wales Sydney New South Wales Australia
| | - Teresa J. Eyre
- QLD Herbarium QLD Department of Environment and Science Toowong Queensland 4066 Australia
| | - Adam McKeown
- CSIRO Land and Water Waite South Australia Australia
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Bell KL, Petit RA, Cutler A, Dobbs EK, Macpherson JM, Read TD, Burgess KS, Brosi BJ. Comparing whole-genome shotgun sequencing and DNA metabarcoding approaches for species identification and quantification of pollen species mixtures. Ecol Evol 2021; 11:16082-16098. [PMID: 34824813 PMCID: PMC8601920 DOI: 10.1002/ece3.8281] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/04/2021] [Accepted: 10/08/2021] [Indexed: 12/12/2022] Open
Abstract
Molecular identification of mixed-species pollen samples has a range of applications in various fields of research. To date, such molecular identification has primarily been carried out via amplicon sequencing, but whole-genome shotgun (WGS) sequencing of pollen DNA has potential advantages, including (1) more genetic information per sample and (2) the potential for better quantitative matching. In this study, we tested the performance of WGS sequencing methodology and publicly available reference sequences in identifying species and quantifying their relative abundance in pollen mock communities. Using mock communities previously analyzed with DNA metabarcoding, we sequenced approximately 200Mbp for each sample using Illumina HiSeq and MiSeq. Taxonomic identifications were based on the Kraken k-mer identification method with reference libraries constructed from full-genome and short read archive data from the NCBI database. We found WGS to be a reliable method for taxonomic identification of pollen with near 100% identification of species in mixtures but generating higher rates of false positives (reads not identified to the correct taxon at the required taxonomic level) relative to rbcL and ITS2 amplicon sequencing. For quantification of relative species abundance, WGS data provided a stronger correlation between pollen grain proportion and sequence read proportion, but diverged more from a 1:1 relationship, likely due to the higher rate of false positives. Currently, a limitation of WGS-based pollen identification is the lack of representation of plant diversity in publicly available genome databases. As databases improve and costs drop, we expect that eventually genomics methods will become the methods of choice for species identification and quantification of mixed-species pollen samples.
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Affiliation(s)
- Karen L Bell
- Department of Environmental Sciences Emory University Atlanta Georgia USA
- Present address: School of Biological Sciences University of Western Australia Perth Australia
- Present address: CSIRO Land & Water and CSIRO Health & Biosecurity Floreat WA Australia
| | - Robert A Petit
- Division of Infectious Diseases Department of Medicine Emory University Atlanta Georgia USA
| | - Anya Cutler
- Department of Environmental Sciences Emory University Atlanta Georgia USA
| | - Emily K Dobbs
- Department of Environmental Sciences Emory University Atlanta Georgia USA
- Present address: Department of Biology Northern Kentucky University Highland Heights Kentucky USA
| | - J Michael Macpherson
- Department of Biology Chapman University Orange California USA
- Present address: 23andMe Mountain View California USA
| | - Timothy D Read
- Division of Infectious Diseases Department of Medicine Emory University Atlanta Georgia USA
| | - Kevin S Burgess
- Department of Biology Columbus State University Columbus Georgia USA
| | - Berry J Brosi
- Department of Environmental Sciences Emory University Atlanta Georgia USA
- Present address: Department of Biology University of Washington Seattle Washington USA
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9
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Bell KL, Lister JJ, Conter R, Harrison Bush AL, O'Brien J. Cognitive Event-Related Potential Responses Differentiate Older Adults with and without Probable Mild Cognitive Impairment. Exp Aging Res 2020; 47:145-164. [PMID: 33342371 DOI: 10.1080/0361073x.2020.1861838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Background: Older adults rarely seek cognitive assessment, but often visit other healthcare professionals (e.g., audiologists). Noninvasive clinical measures within the scopes of practice of those professions sensitive to cognitive impairment are needed. Purpose: This study examined the differences of probable mild cognitive impairment (MCI) on latency and mean amplitude of the P3b auditory event-related potential. Method: Fifty-four participants comprised two groups according to cognitive status (cognitively normal older adults [CNOA], n = 25; probable MCI, n = 29). P3b was recorded using an oddball paradigm for speech (/ba/, /da/) and non-speech (1000, 2000 Hz) stimuli. Amplitudes and latencies were compared from six electrodes (FPz, Fz, FCz, Cz, CPz, Pz) between groups across stimulus probability and type. Results: CNOA participants had larger P3b mean amplitudes for deviant stimuli than those with probable MCI. Group effects of latency were isolated to deviant stimuli at FCz only when those with unclear P3bs were included. Findings did not covary with age or education. Overall, CNOAs showed a large P3b oddball effect while those with probable MCI did not. Conclusions: P3b can be used to show electrophysiological differences between older adults with and without probable MCI. These results support the development of educational materials targeting professionals using auditory-evoked potentials.
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Affiliation(s)
- Karen L Bell
- Department of Communication Sciences and Disorders, University of South Florida , Tampa, Florida, USA
| | - Jennifer Jones Lister
- Department of Communication Sciences and Disorders, University of South Florida , Tampa, Florida, USA
| | - Rachel Conter
- Department of Communication Sciences and Disorders, University of South Florida , Tampa, Florida, USA
| | - Aryn L Harrison Bush
- Department of Communication Sciences and Disorders, University of South Florida , Tampa, Florida, USA.,Department of Brain Health and Cognition, Reliance Medical Centers , Lakeland, Florida, USA
| | - Jennifer O'Brien
- Department of Psychology, University of South Florida , Tampa, Florida, USA
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10
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Devanand DP, Andrews H, Kreisl WC, Razlighi Q, Gershon A, Stern Y, Mintz A, Wisniewski T, Acosta E, Pollina J, Katsikoumbas M, Bell KL, Pelton GH, Deliyannides D, Prasad KM, Huey ED. Antiviral therapy: Valacyclovir Treatment of Alzheimer's Disease (VALAD) Trial: protocol for a randomised, double-blind,placebo-controlled, treatment trial. BMJ Open 2020; 10:e032112. [PMID: 32034019 PMCID: PMC7045215 DOI: 10.1136/bmjopen-2019-032112] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/16/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION After infection, herpes simplex virus-1 (HSV1) becomes latent in the trigeminal ganglion and can enter the brain via retrograde axonal transport. Recurrent reactivation of HSV1 may lead to neurodegeneration and Alzheimer's disease (AD) pathology. HSV1 (oral herpes) and HSV2 (genital herpes) can trigger amyloid beta-protein (Aβ) aggregation and HSV1 DNA is common in amyloid plaques. Anti-HSV drugs reduce Aβ and phosphorylated tau accumulation in cell-culture models. Cognitive impairment is greater in patients with HSV seropositive, and antiviral drugs show robust efficacy against peripheral HSV infection. Recent studies of electronic health records databases demonstrate that HSV infections increase dementia risk, and that antiviral medication treatment reduces this risk. The generic antiviral drug valacyclovir was superior to placebo in improving memory in a schizophrenia pilot trial but has not been tested in AD. METHODS AND ANALYSIS In patients with mild AD who test positive for HSV1 or HSV2 serum antibodies, valacyclovir, repurposed as an anti-AD drug, will be compared with placebo (lactose pills) in 130 patients (65 valacyclovir and 65 placebo) in a randomised, double-blind, 78-week phase II proof-of-concept trial. Patients on valacyclovir, dose-titrated from 2 g to a targeted oral dose of 4 g daily, compared with placebo, are hypothesised to show smaller cognitive and functional decline, and, using 18F-Florbetapir positron emission tomography (PET) and 18F-MK-6240 PET imaging, to show less amyloid and tau accumulation, respectively. In the lumbar puncture subsample, cerebrospinal fluid acyclovir will be assayed to assess central nervous system valacyclovir penetration. ETHICS AND DISSEMINATION The trial is being overseen by the New York State Psychiatric Institute Institutional Review Board (protocol 7537), the National Institute on Ageing, and the Data Safety Monitoring Board. Written informed consent is obtained for all subjects. Results will be disseminated via publication, clinicaltrials.gov, media and conferences. TRIAL REGISTRATION NUMBER ClinicalTrials.gov identifier (NCT03282916) Pre-results.
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Affiliation(s)
- D P Devanand
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Howard Andrews
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
- Department of Biostatistics, Columbia University Medical Center, New York, New York, USA
| | - William C Kreisl
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Qolamreza Razlighi
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Anne Gershon
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Yaakov Stern
- Department of Psychiatry, Columbia University, New York, New York, USA
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Akiva Mintz
- Department of Radiology, Columbia University Medical Center, New York, New York, USA
| | - Thomas Wisniewski
- Center for Cognitive Neurology, Departments of Neurology, New York University Medical Center, New York, New York, USA
| | - Edward Acosta
- Department of Pharmacology, University of Alabama, Tuscaloosa, Alabama, USA
| | - Julianna Pollina
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
| | - Mariasofia Katsikoumbas
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
| | - Karen L Bell
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Gregory H Pelton
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
| | - Deborah Deliyannides
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
| | - K M Prasad
- Departments of Psychiatry and Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania, USA
| | - Edward D Huey
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, New York, New York, USA
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, USA
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Bell KL, Batchelor KL, Bradford M, McKeown A, Macdonald SL, Westcott D. Optimisation of a pollen DNA metabarcoding method for diet analysis of flying-foxes (Pteropus spp.). AUST J ZOOL 2020. [DOI: 10.1071/zo20085] [Citation(s) in RCA: 5] [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: 01/23/2023]
Abstract
Determining the diet of flying-foxes can increase understanding of how they function as pollinators and seed dispersers, as well as managing any negative impacts of large roosts. Traditional methods for diet analysis are time consuming, and not feasible to conduct for hundreds of animals. In this study, we optimised a method for diet analysis, based on DNA metabarcoding of environmental DNA (eDNA) from pollen and other plant parts in the faeces. We found that existing eDNA metabarcoding protocols are suitable, with the most useful results being obtained using a commercial food DNA extraction kit, and sequencing 350–450 base pairs of a DNA barcode from the internally transcribed spacer region (ITS2), with ~550 base pairs of the chloroplast rubisco large subunit (rbcL) as a secondary DNA barcode. A list of forage plants was generated for the little red flying-fox (Pteropus scapulatus), the black flying-fox (Pteropus alecto) and the spectacled flying-fox (Pteropus conspicillatus) from our collection sites across Queensland. The diets were determined to comprise predominantly Myrtaceae species, particularly those in the genera Eucalyptus, Melaleuca and Corymbia. With more plant genomes becoming publicly available in the future, there are likely to be further applications of eDNA methods in understanding the role of flying-foxes as pollinators and seed dispersers.
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Hoover EC, Kinney BN, Bell KL, Gallun FJ, Eddins DA. A Comparison of Behavioral Methods for Indexing the Auditory Processing of Temporal Fine Structure Cues. J Speech Lang Hear Res 2019; 62:2018-2034. [PMID: 31145649 PMCID: PMC6808371 DOI: 10.1044/2019_jslhr-h-18-0217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 12/20/2018] [Accepted: 02/13/2019] [Indexed: 05/12/2023]
Abstract
Purpose Growing evidence supports the inclusion of perceptual tests that quantify the processing of temporal fine structure (TFS) in clinical hearing assessment. Many tasks have been used to evaluate TFS in the laboratory that vary greatly in the stimuli used and whether the judgments require monaural or binaural comparisons of TFS. The purpose of this study was to compare laboratory measures of TFS for inclusion in a battery of suprathreshold auditory tests. A subset of available TFS tasks were selected on the basis of potential clinical utility and were evaluated using metrics that focus on characteristics important for clinical use. Method TFS measures were implemented in replication of studies that demonstrated clinical utility. Monaural, diotic, and dichotic measures were evaluated in 11 young listeners with normal hearing. Measures included frequency modulation (FM) tasks, harmonic frequency shift detection, interaural phase difference (TFS-low frequency), interaural time difference (ITD), monaural gap duration discrimination, and tone detection in noise with and without a difference in interaural phase (N0S0, N0Sπ). Data were compared with published results and evaluated with metrics of consistency and efficiency. Results Thresholds obtained were consistent with published data. There was no evidence of predictive relationships among the measures consistent with a homogenous group. The most stable tasks across repeated testing were TFS-low frequency, diotic and dichotic FM, and N0Sπ. Monaural and diotic FM had the lowest normalized variance and were the most efficient accounting for differences in total test duration, followed by ITD. Conclusions Despite a long stimulus duration, FM tasks dominated comparisons of consistency and efficiency. Small differences separated the dichotic tasks FM, ITD, and N0Sπ. Future comparisons following procedural optimization of the tasks will evaluate clinical efficiency in populations with impairment.
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Affiliation(s)
- Eric C. Hoover
- Department of Communication Sciences and Disorders, University of South Florida, Tampa
| | - Brianna N. Kinney
- Department of Communication Sciences and Disorders, University of South Florida, Tampa
| | - Karen L. Bell
- Department of Communication Sciences and Disorders, University of South Florida, Tampa
| | - Frederick J. Gallun
- National Center for Rehabilitative Auditory Research, Portland VA Medical Center, Oregon
- Department of Otolaryngology–Head and Neck Surgery, Oregon Health and Science University, Portland
| | - David A. Eddins
- Department of Communication Sciences and Disorders, University of South Florida, Tampa
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Dormontt EE, van Dijk KJ, Bell KL, Biffin E, Breed MF, Byrne M, Caddy-Retalic S, Encinas-Viso F, Nevill PG, Shapcott A, Young JM, Waycott M, Lowe AJ. Advancing DNA Barcoding and Metabarcoding Applications for Plants Requires Systematic Analysis of Herbarium Collections—An Australian Perspective. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00134] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Bell KL, Burgess KS, Botsch JC, Dobbs EK, Read TD, Brosi BJ. Quantitative and qualitative assessment of pollen
DNA
metabarcoding using constructed species mixtures. Mol Ecol 2018; 28:431-455. [DOI: 10.1111/mec.14840] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/20/2018] [Accepted: 07/28/2018] [Indexed: 01/04/2023]
Affiliation(s)
- Karen L. Bell
- Department of Environmental Sciences Emory University Atlanta Georgia
| | - Kevin S. Burgess
- Columbus State University Department of Biology Columbus Georgia
| | | | - Emily K. Dobbs
- Department of Environmental Sciences Emory University Atlanta Georgia
| | - Timothy D. Read
- Division of Infectious Diseases Department of Human Genetics School of Medicine Emory University Atlanta Georgia
| | - Berry J. Brosi
- Department of Environmental Sciences Emory University Atlanta Georgia
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Bell KL, Fowler J, Burgess KS, Dobbs EK, Gruenewald D, Lawley B, Morozumi C, Brosi BJ. Applying pollen DNA metabarcoding to the study of plant-pollinator interactions. Appl Plant Sci 2017; 5:apps1600124. [PMID: 28690929 PMCID: PMC5499302 DOI: 10.3732/apps.1600124] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 03/09/2017] [Indexed: 05/25/2023]
Abstract
PREMISE OF THE STUDY To study pollination networks in a changing environment, we need accurate, high-throughput methods. Previous studies have shown that more highly resolved networks can be constructed by studying pollen loads taken from bees, relative to field observations. DNA metabarcoding potentially allows for faster and finer-scale taxonomic resolution of pollen compared to traditional approaches (e.g., light microscopy), but has not been applied to pollination networks. METHODS We sampled pollen from 38 bee species collected in Florida from sites differing in forest management. We isolated DNA from pollen mixtures and sequenced rbcL and ITS2 gene regions from all mixtures in a single run on the Illumina MiSeq platform. We identified species from sequence data using comprehensive rbcL and ITS2 databases. RESULTS We successfully built a proof-of-concept quantitative pollination network using pollen metabarcoding. DISCUSSION Our work underscores that pollen metabarcoding is not quantitative but that quantitative networks can be constructed based on the number of interacting individuals. Due to the frequency of contamination and false positive reads, isolation and PCR negative controls should be used in every reaction. DNA metabarcoding has advantages in efficiency and resolution over microscopic identification of pollen, and we expect that it will have broad utility for future studies of plant-pollinator interactions.
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Affiliation(s)
- Karen L. Bell
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
- School of Biological Sciences, The University of Western Australia, Perth, Western Australia 6008, Australia
- CSIRO Land and Water and CSIRO Health and Biosecurity, 147 Underwood Avenue, Floreat, Western Australia 6014, Australia
| | - Julie Fowler
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
| | - Kevin S. Burgess
- Department of Biology, Columbus State University, Columbus, Georgia 31907-5645 USA
| | - Emily K. Dobbs
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
| | - David Gruenewald
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
| | - Brice Lawley
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
| | - Connor Morozumi
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
| | - Berry J. Brosi
- Department of Environmental Sciences, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
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Bell KL, Rangan H, Fernandes MM, Kull CA, Murphy DJ. Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution. R Soc Open Sci 2017; 4:170105. [PMID: 28484637 PMCID: PMC5414274 DOI: 10.1098/rsos.170105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 03/15/2017] [Indexed: 06/07/2023]
Abstract
Acacia s.l. farnesiana, which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human-mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human-mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal for disjunct plant distributions.
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Affiliation(s)
- Karen L. Bell
- Royal Botanic Gardens Victoria, Melbourne, Victoria 3004, Australia
| | - Haripriya Rangan
- Australia India Institute and School of Geography, University of Melbourne, Victoria 3053, Australia
- Monash Indigenous Centre, Monash University, Victoria 3800, Australia
| | - Manuel M. Fernandes
- Centro de Estudos de Geografia e Ordenamento Território, Universidade do Porto, Portugal
| | - Christian A. Kull
- Institut de Géographie et Durabilité, Université de Lausanne, Lausanne 1015, Switzerland
| | - Daniel J. Murphy
- Royal Botanic Gardens Victoria, Melbourne, Victoria 3004, Australia
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Bell KL, Loeffler VM, Brosi BJ. An rbcL reference library to aid in the identification of plant species mixtures by DNA metabarcoding. Appl Plant Sci 2017; 5:apps1600110. [PMID: 28337390 PMCID: PMC5357121 DOI: 10.3732/apps.1600110] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 01/30/2017] [Indexed: 05/03/2023]
Abstract
PREMISE OF THE STUDY DNA metabarcoding has broad-ranging applications in ecology, aerobiology, biosecurity, and forensics. A bioinformatics pipeline has recently been published for identification using a comprehensive database of ITS2, one of the common plant DNA barcoding markers. There is, however, no corresponding database for rbcL, the other primary marker used in plants. METHODS Using publicly available data, we compiled a reference library of rbcL sequences and trained databases for use with UTAX and RDP classifier algorithms. We used this reference library, along with the existing bioinformatics pipeline and ITS2 reference library, to identify species in an artificial mixture of nine species of pollen. We have made this database publicly available in multiple formats, to allow use with multiple bioinformatics pipelines, now and in the future. RESULTS Using the rbcL database, in addition to the ITS2 database, we succeeded in making species-level identifications for eight species and a family-level identification of the ninth species. This is an improvement on ITS2 sequence alone. DISCUSSION The reference library described here will assist with identification of plant species using rbcL. By making another gene region available for standard barcoding, this will increase the resolution and accuracy of identifications.
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Affiliation(s)
- Karen L. Bell
- Department of Environmental Science, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
- Author for correspondence:
| | - Virginia M. Loeffler
- Department of Environmental Science, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
| | - Berry J. Brosi
- Department of Environmental Science, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322 USA
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Abstract
Identification of the species origin of pollen has many applications, including assessment of plant–pollinator networks, reconstruction of ancient plant communities, product authentication, allergen monitoring, and forensics. Such applications, however, have previously been limited by microscopy-based identification of pollen, which is slow, has low taxonomic resolution, and has few expert practitioners. One alternative is pollen DNA barcoding, which could overcome these issues. Recent studies demonstrate that both chloroplast and nuclear barcoding markers can be amplified from pollen. These recent validations of pollen metabarcoding indicate that now is the time for researchers in various fields to consider applying these methods to their research programs. In this paper, we review the nascent field of pollen DNA barcoding and discuss potential new applications of this technology, highlighting existing limitations and future research developments that will improve its utility in a wide range of applications.
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Affiliation(s)
- Karen L. Bell
- Emory University, School of Environmental Sciences, Atlanta, GA, USA
| | - Natasha de Vere
- National Botanic Garden of Wales, Llanarthne, United Kingdom
| | - Alexander Keller
- Department of Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany
| | | | - Annemarie Gous
- Biotechnology Platform, Agricultural Research Council, Pretoria, South Africa
- School of Life Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | | | - Berry J. Brosi
- Emory University, School of Environmental Sciences, Atlanta, GA, USA
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Bell KL, Rangan H, Kull CA, Murphy DJ. The history of introduction of the African baobab (Adansonia digitata, Malvaceae: Bombacoideae) in the Indian subcontinent. R Soc Open Sci 2015; 2:150370. [PMID: 26473060 PMCID: PMC4593694 DOI: 10.1098/rsos.150370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 08/14/2015] [Indexed: 05/26/2023]
Abstract
To investigate the pathways of introduction of the African baobab, Adansonia digitata, to the Indian subcontinent, we examined 10 microsatellite loci in individuals from Africa, India, the Mascarenes and Malaysia, and matched this with historical evidence of human interactions between source and destination regions. Genetic analysis showed broad congruence of African clusters with biogeographic regions except along the Zambezi (Mozambique) and Kilwa (Tanzania), where populations included a mixture of individuals assigned to at least two different clusters. Individuals from West Africa, the Mascarenes, southeast India and Malaysia shared a cluster. Baobabs from western and central India clustered separately from Africa. Genetic diversity was lower in populations from the Indian subcontinent than in African populations, but the former contained private alleles. Phylogenetic analysis showed Indian populations were closest to those from the Mombasa-Dar es Salaam coast. The genetic results provide evidence of multiple introductions of African baobabs to the Indian subcontinent over a longer time period than previously assumed. Individuals belonging to different genetic clusters in Zambezi and Kilwa may reflect the history of trafficking captives from inland areas to supply the slave trade between the fifteenth and nineteenth centuries. Baobabs in the Mascarenes, southeast India and Malaysia indicate introduction from West Africa through eighteenth and nineteenth century European colonial networks.
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Affiliation(s)
- Karen L. Bell
- Royal Botanic Gardens Victoria, Melbourne, Victoria 3004, Australia
| | - Haripriya Rangan
- School of Geography, University of Melbourne, Victoria 3053, Australia
| | - Christian A. Kull
- Institut de Géographie et Durabilité, Université de Lausanne, Lausanne 1015, Switzerland
| | - Daniel J. Murphy
- Royal Botanic Gardens Victoria, Melbourne, Victoria 3004, Australia
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Rangan H, Bell KL, Baum DA, Fowler R, McConvell P, Saunders T, Spronck S, Kull CA, Murphy DJ. New genetic and linguistic analyses show ancient human influence on baobab evolution and distribution in Australia. PLoS One 2015; 10:e0119758. [PMID: 25830225 PMCID: PMC4382155 DOI: 10.1371/journal.pone.0119758] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 02/02/2015] [Indexed: 11/19/2022] Open
Abstract
This study investigates the role of human agency in the gene flow and geographical distribution of the Australian baobab, Adansonia gregorii. The genus Adansonia is a charismatic tree endemic to Africa, Madagascar, and northwest Australia that has long been valued by humans for its multiple uses. The distribution of genetic variation in baobabs in Africa has been partially attributed to human-mediated dispersal over millennia, but this relationship has never been investigated for the Australian species. We combined genetic and linguistic data to analyse geographic patterns of gene flow and movement of word-forms for A. gregorii in the Aboriginal languages of northwest Australia. Comprehensive assessment of genetic diversity showed weak geographic structure and high gene flow. Of potential dispersal vectors, humans were identified as most likely to have enabled gene flow across biogeographic barriers in northwest Australia. Genetic-linguistic analysis demonstrated congruence of gene flow patterns and directional movement of Aboriginal loanwords for A. gregorii. These findings, along with previous archaeobotanical evidence from the Late Pleistocene and Holocene, suggest that ancient humans significantly influenced the geographic distribution of Adansonia in northwest Australia.
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Affiliation(s)
- Haripriya Rangan
- Centre for Geography and Environmental Science, Monash University, Melbourne VIC, 3800, Australia
- * E-mail:
| | - Karen L. Bell
- Centre for Geography and Environmental Science, Monash University, Melbourne VIC, 3800, Australia
- Royal Botanic Gardens Melbourne, South Yarra, VIC, 3141, Australia
| | - David A. Baum
- Department of Botany, University of Wisconsin-Madison, Madison, WI, 53706, United States of America
| | - Rachael Fowler
- Centre for Geography and Environmental Science, Monash University, Melbourne VIC, 3800, Australia
- Royal Botanic Gardens Melbourne, South Yarra, VIC, 3141, Australia
| | - Patrick McConvell
- School of Language Studies, The Australian National University, Canberra, ACT, 0200, Australia
| | - Thomas Saunders
- Independent Researcher—Linguist, PO Box 10, Derby, WA, 6728, Australia
| | - Stef Spronck
- Linguistics, School of Culture, History, and Language, The Australian National University, Canberra, ACT, 0200, Australia
- Linguistics, Katholieke Universiteit Leuven, 3000, Leuven, Belgium
| | - Christian A. Kull
- Centre for Geography and Environmental Science, Monash University, Melbourne VIC, 3800, Australia
- Institut de Géographie et Durabilité, Universitie de Lausanne, Lausanne, CH, 1015, Switzerland
| | - Daniel J. Murphy
- Royal Botanic Gardens Melbourne, South Yarra, VIC, 3141, Australia
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Abstract
Children with severe cerebral palsy and particularly those with oropharyngeal dysfunction are at risk of poor nutritional status. Determining the need and the mode of nutritional intervention is multifactorial and requires multiple methodologies. First-line treatment typically involves oral nutritional support for those children who are safe to consume an oral diet. Enteral tube feeding may need to be considered in children with undernutrition where poor weight gain continues despite oral nutritional support, or in those with oropharyngeal dysphagia and an unsafe swallow. Estimates for energy and protein requirements provide a starting point only, and ongoing assessment and monitoring is essential to ensure nutritional needs are being met, that complications are adequately managed and to avoid over or under feeding.
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Affiliation(s)
- K L Bell
- 1] Queensland Cerebral Palsy and Rehabilitation Research Centre, Children's Nutrition Research Centre, Queensland Children's Medical Research Institute, The University of Queensland, Brisbane, Queensland, Australia [2] Department of Paediatric Rehabilitation, Children's Health Queensland Hospital and Health Service, Herston, Brisbane, Queensland, Australia
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Bell KL, Murphy DJ, Gardner MG. Isolation, via 454 sequencing, and characterization of microsatellites for Vachellia farnesiana (Fabaceae: Mimosoideae). Appl Plant Sci 2013; 1:apps1300035. [PMID: 25202489 PMCID: PMC4103469 DOI: 10.3732/apps.1300035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 06/14/2013] [Indexed: 05/27/2023]
Abstract
PREMISE OF THE STUDY We isolated 15 polymorphic microsatellite markers from Vachellia farnesiana for use in population genetic studies to determine the native range of the species. • METHODS AND RESULTS Initially, 454 shotgun sequencing was used to identify and design primers for 68 microsatellite loci. Of these, we trialed 47 loci in the target species, and 42 (89%) amplified a product of expected size. Fifteen of the 47 loci were screened for variation in 21 individuals from the native range of V. farnesiana in southern Mexico and 20 from northwestern Australia. Fourteen loci were polymorphic, with observed heterozygosity ranging from 0.026 to 1.00 (mean = 0.515) and two to 12 alleles per locus (average = 5.2). Cross-amplification was successful in four to 11 loci in three other Vachellia species. • CONCLUSIONS The new microsatellite loci will be useful in understanding genetic variation and investigating the role of human-mediated dispersal in the current distribution of V. farnesiana.
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Affiliation(s)
- Karen L. Bell
- Royal Botanic Gardens Melbourne, Birdwood Avenue, South Yarra, Victoria 3141, Australia
- School of Geography and Environmental Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Daniel J. Murphy
- Royal Botanic Gardens Melbourne, Birdwood Avenue, South Yarra, Victoria 3141, Australia
| | - Michael G. Gardner
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, 5001 South Australia, Australia
- Australian Centre for Evolutionary Biology and Biodiversity, University of Adelaide, Adelaide, 5005 South Australia, Australia
- Evolutionary Biology Unit, South Australian Museum, North Terrace Adelaide, 5000 South Australia, Australia
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Sano M, Bell KL, Galasko D, Galvin JE, Thomas RG, van Dyck CH, Aisen PS. A randomized, double-blind, placebo-controlled trial of simvastatin to treat Alzheimer disease. Neurology 2011; 77:556-63. [PMID: 21795660 PMCID: PMC3149154 DOI: 10.1212/wnl.0b013e318228bf11] [Citation(s) in RCA: 209] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 04/05/2011] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Lowering cholesterol is associated with reduced CNS amyloid deposition and increased dietary cholesterol increases amyloid accumulation in animal studies. Epidemiologic data suggest that use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) may decrease the risk of Alzheimer disease (AD) and a single-site trial suggested possible benefit in cognition with statin treatment in AD, supporting the hypothesis that statin therapy is useful in the treatment of AD. OBJECTIVE To determine if the lipid-lowering agent simvastatin slows the progression of symptoms in AD. METHODS This randomized, double-blind, placebo-controlled trial of simvastatin was conducted in individuals with mild to moderate AD and normal lipid levels. Participants were randomly assigned to receive simvastatin, 20 mg/day, for 6 weeks then 40 mg per day for the remainder of 18 months or identical placebo. The primary outcome was the rate of change in the Alzheimer's Disease Assessment Scale-cognitive portion (ADAS-Cog). Secondary outcomes measured clinical global change, cognition, function, and behavior. RESULTS A total of 406 individuals were randomized: 204 to simvastatin and 202 to placebo. Simvastatin lowered lipid levels but had no effect on change in ADAS-Cog score or the secondary outcome measures. There was no evidence of increased adverse events with simvastatin treatment. CONCLUSION Simvastatin had no benefit on the progression of symptoms in individuals with mild to moderate AD despite significant lowering of cholesterol. CLASSIFICATION OF EVIDENCE This study provides Class I evidence that simvastatin 40 mg/day does not slow decline on the ADAS-Cog.
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Affiliation(s)
- M Sano
- Mount Sinai School of Medicine, Bronx, NY 10468, USA.
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Pastore M, Chin SS, Bell KL, Dong Z, Yang Q, Yang L, Yuan J, Chen SG, Gambetti P, Zou WQ. Creutzfeldt-Jakob disease (CJD) with a mutation at codon 148 of prion protein gene: relationship with sporadic CJD. Am J Pathol 2006; 167:1729-38. [PMID: 16314483 PMCID: PMC1613192 DOI: 10.1016/s0002-9440(10)61254-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Creutzfeldt-Jakob disease (CJD), the most common human prion disease, includes sporadic (s) and familial (f) forms. Regardless of etiology, both forms are thought to share the pathogenic mechanism whereby the cellular prion protein (PrP(C)) converts into its pathogenic isoform (PrP(Sc)). While PrP(C) conversion is thought to be random in sCJD, conversion in fCJD is facilitated by the congenital presence of mutated PrP. Differences in PrP genotype (PRNP) and in conversion circumstances lead to PrP(Sc) with distinct characteristics that elicit different disease phenotypes. Here, we describe a case of fCJD with a substitution of histidine (H) for arginine (R) at codon 148 (R148H) and heterozygosity of the methionine/valine (M/V) polymorphic codon 129, with the 129M allele coupled with the mutation. The disease phenotype and all major characteristics of PrP(Sc) of fCJD(R148H) were virtually indistinguishable from those of sCJDMV2, which has features different from those of any other sCJD. Therefore, despite the differences in etiology, PRNP, and conversion process, the two forms of PrP(Sc) had similar characteristics. Furthermore, comparison of fCJD(R148H) with a recently reported case carrying R148H and homozygosity at codon 129 suggests that codon 129 coupled with the mutation as well as that located on the normal allele can modify major phenotypic and PrP(Sc) features of fCJD(R148H).
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Affiliation(s)
- Manuela Pastore
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
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Sano M, Jacobs DM, Bell KL, Andrews HF, Tsai W, Lucas JA, Graff‐Radford NR, Bolla KI, Rabins P. [O2‐02‐06]: Using family history to enrich recruitment in prevention trials: Does relative's age matter? Alzheimers Dement 2005. [DOI: 10.1016/j.jalz.2005.06.339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Mary Sano
- Mount Sinai School of MedicineBronxNYUSA
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Noe E, Marder K, Bell KL, Jacobs DM, Manly JJ, Stern Y. Comparison of dementia with Lewy bodies to Alzheimer's disease and Parkinson's disease with dementia. Mov Disord 2004; 19:60-7. [PMID: 14743362 DOI: 10.1002/mds.10633] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [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: 11/05/2022] Open
Abstract
We compared the clinical and neuropsychological pattern of dementia with Lewy bodies (DLB) to Alzheimer's disease (AD) and Parkinson's disease with dementia (PD-d). Sixteen patients clinically diagnosed with DLB were compared with two groups of patients with PD-d (n = 15) and AD (n = 16) matched for level of dementia. Isolated cognitive impairment was the most common form of presentation in AD (93.8%) and DLB (31.3%) groups, while parkinsonism was in 100% of PD-d subjects. Psychoses associated with cognitive impairment at the beginning of the disease were more frequent in DLB patients (31.3%) than in AD (6.3%) and PD-d (0%) groups. There were no significant differences in Unified Parkinson Disease Rating Scale motor-subscale scores between DLB and PD-d patients. DLB and PD-d patients performed significantly worse on attentional functions and better on memory tests than AD. DLB patients also showed lower scores than AD subjects on visual memory, visuoperceptive, and visuoconstructive tests. No significant differences were found between PD-d group and DLB subjects on any neuropsychological test. We were unable to find any differences in cognitive tasks between PD-d and DLB subjects. Clinical features and neuropsychological deficiencies of DLB (attentional, visuoperceptive, and visuoconstructive deficits) and PD (attentional deficits) compared to AD (amnesic syndrome) can contribute to accurate identification of these entities and to the understanding of the neuropathological and neurochemical substrate underlying these diseases.
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Affiliation(s)
- Enrique Noe
- Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, USA.
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Bell KL, Yeates DK, Moritz C, Monteith GB. Molecular phylogeny and biogeography of the dung beetle genus Temnoplectron Westwood (Scarabaeidae: Scarabaeinae) from Australia’s wet tropics. Mol Phylogenet Evol 2004; 31:741-53. [PMID: 15062807 DOI: 10.1016/j.ympev.2003.09.010] [Citation(s) in RCA: 30] [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] [Received: 06/17/2003] [Revised: 09/08/2003] [Indexed: 11/26/2022]
Abstract
The landscape of the Australian Wet Tropics can be described as "islands" of montane rainforest surrounded by warmer or more xeric habitats. Historical glaciation cycles have caused expansion and contraction of these rainforest "islands" leading to consistent patterns of genetic divergence within species of vertebrates. To explore whether this dynamic history has promoted speciation in endemic and diverse groups of insects, we used a combination of mtDNA sequencing and morphological characters to estimate relationships and the tempo of divergence among Australian representatives of the dung beetle genus Temnoplectron. This phylogenetic hypothesis shares a number of well-supported clades with a previously published phylogenetic hypothesis based on morphological data, though statistical support for several nodes is weak. Sister species relationships well-supported in both tree topologies, and a tree obtained by combining the two data sets, suggest that speciation has mostly been allopatric. We identify a number of speciation barriers, which coincide with phylogeographic breaks found in vertebrate species. Large sequence divergences between species emphasize that speciation events are ancient (pre-Pleistocene). The flightless, rainforest species appear to have speciated rapidly, but also in the distant past.
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Affiliation(s)
- K L Bell
- Queensland Museum, Brisbane, Queensland 4000, Australia.
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Heidari R, Devonshire AL, Campbell BE, Bell KL, Dorrian SJ, Oakeshott JG, Russell RJ. Hydrolysis of organophosphorus insecticides by in vitro modified carboxylesterase E3 from Lucilia cuprina. Insect Biochem Mol Biol 2004; 34:353-363. [PMID: 15041019 DOI: 10.1016/j.ibmb.2004.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Revised: 01/16/2004] [Accepted: 01/19/2004] [Indexed: 05/24/2023]
Abstract
Resistance of the blowfly, Lucilia cuprina, to organophosphorus (OP) insecticides is due to mutations in LcalphaE7, the gene encoding carboxylesterase E3, that enhance the enzyme's ability to hydrolyse insecticides. Two mutations occur naturally, G137D in the oxyanion hole of the esterase, and W251L in the acyl binding pocket. Previous in vitro mutagenesis and expression of these modifications to the cloned gene have confirmed their functional significance. G137D enhances hydrolysis of diethyl and dimethyl phosphates by 55- and 33-fold, respectively. W251L increases dimethyl phosphate hydrolysis similarly, but only 10-fold for the diethyl homolog; unlike G137D however, it also retains ability to hydrolyse carboxylesters in the leaving group of malathion (malathion carboxylesterase, MCE), conferring strong resistance to this compound. In the present work, we substituted these and nearby amino acids by others expected to affect the efficiency of the enzyme. Changing G137 to glutamate or histidine was less effective than aspartate in improving OP hydrolase activity and like G137D, it diminished MCE activity, primarily through increases in Km. Various substitutions of W251 to other smaller residues had a broadly similar effect to W251L on OP hydrolase and MCE activities, but at least two were quantitatively better in kinetic parameters relating to malathion resistance. One, W251G, which occurs naturally in a malathion resistant hymenopterous parasitoid, improved MCE activity more than 20-fold. Mutations at other sites near the bottom of the catalytic cleft generally diminished OP hydrolase and MCE activities but one, F309L, also yielded some improvements in OP hydrolase activities. The results are discussed in relation to likely steric effects on enzyme-substrate interactions and future evolution of this gene.
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Affiliation(s)
- R Heidari
- CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia
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Abstract
Investigations of the actions of estrogen on the skeleton have mainly focused on cancellous bone and there are no reported histomorphometric studies of the effects of oestrogen on cortical bone in humans. The aim of this study was to investigate the effects of both conventional hormone replacement therapy (HRT) and high-dose oestradiol on cortical bone in postmenopausal women. Transiliac biopsies were obtained from nine postmenopausal women aged 54-71 yr before and after 2 yr (mean, 23.5 months) of conventional HRT and in seven postmenopausal women aged 52-67 yr after long-term, high-dose oestradiol implant therapy (at least 14 yr). Indices of bone turnover, remodeling, and cortical structure were assessed by image analysis. Cortical width was highest in the women treated with high-dose oestrogen therapy (2.29 +/- 0.78 mm; mean +/- SD) and lowest in untreated women (1.36 +/- 0.60 mm; P=0.014). The proportion of canals with an eroded surface was significantly lower in the high-dose oestrogen group than in women before or after conventional HRT (3.03 +/- 3.7% vs. 11.1 +/- 7.1% and 10.5 +/- 8.6%; P=0.017 and 0.05, respectively). Bone formation rate (microm2/microm/day) in untreated women was significantly higher than in the high-dose oestrogen group (0.121 +/- 0.072 vs. 0.066 +/- 0.045, respectively; P=0.05), values in women treated with conventional HRT being intermediate. Our results provide the first histomorphometric evidence in postmenopausal women of dose-dependent oestrogen-induced suppression of bone turnover in iliac crest cortical bone. There was also a trend toward higher wall width with increasing dose of oestrogen, consistent with the previously reported anabolic effect in cancellous bone.
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Affiliation(s)
- S Vedi
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
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Scarmeas N, Zarahn E, Anderson KE, Habeck CG, Hilton J, Flynn J, Marder KS, Bell KL, Sackeim HA, Van Heertum RL, Moeller JR, Stern Y. Association of life activities with cerebral blood flow in Alzheimer disease: implications for the cognitive reserve hypothesis. Arch Neurol 2003; 60:359-65. [PMID: 12633147 PMCID: PMC3028534 DOI: 10.1001/archneur.60.3.359] [Citation(s) in RCA: 179] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Regional cerebral blood flow (CBF), a good indirect index of cerebral pathologic changes in Alzheimer disease (AD), is more severely reduced in patients with higher educational attainment and IQ when controlling for clinical severity. This has been interpreted as suggesting that cognitive reserve allows these patients to cope better with the pathologic changes in AD. OBJECTIVE To evaluate whether premorbid engagement in various activities may also provide cognitive reserve. DESIGN We evaluated intellectual, social, and physical activities in 9 patients with early AD and 16 healthy elderly controls who underwent brain H(2)(15)O positron emission tomography. In voxelwise multiple regression analyses that controlled for age and clinical severity, we investigated the association between education, estimated premorbid IQ, and activities, and CBF. RESULTS In accordance with previous findings, we replicated an inverse association between education and CBF and IQ and CBF in patients with AD. In addition, there was a negative correlation between previous reported activity score and CBF in patients with AD. When both education and IQ were added as covariates in the same model, a higher activity score was still associated with more prominent CBF deficits. No significant associations were detected in the controls. CONCLUSIONS At any given level of clinical disease severity, there is a greater degree of brain pathologic involvement in patients with AD who have more engagement in activities, even when education and IQ are taken into account. This may suggest that interindividual differences in lifestyle may affect cognitive reserve by partially mediating the relationship between brain damage and the clinical manifestation of AD.
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Affiliation(s)
- Nikolaos Scarmeas
- Cognitive Neuroscience Division of the Taub Institute for Research in Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
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Jordan GR, Loveridge N, Bell KL, Power J, Dickson GR, Vedi S, Rushton N, Clarke MT, Reeve J. Increased femoral neck cancellous bone and connectivity in coxarthrosis (hip osteoarthritis). Bone 2003; 32:86-95. [PMID: 12584040 DOI: 10.1016/s8756-3282(02)00920-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Patients with coxarthrosis (cOA) have a reduced incidence of intracapsular femoral neck fracture, suggesting that cOA offers protection. The distribution of bone in the femoral neck was compared in cases of coxarthrosis and postmortem controls to assess the possibility that disease-associated changes might contribute to reduced fragility. Whole cross-section femoral neck biopsies were obtained from 17 patients with cOA and 22 age- and sex-matched cadaveric controls. Densitometry was performed using peripheral quantitated computed tomography (pQCT) and histomorphometry on 10-microm plastic-embedded sections. Cortical bone mass was not different between cases and controls (P > 0.23), but cancellous bone mass was increased by 75% in cOA (P = 0.014) and histomorphometric cancellous bone area by 71% (P < 0.0001). This was principally the result of an increase of apparent density (mass/vol) of cancellous bone (+45%, P = 0.001). Whereas cortical porosity was increased in the cases (P < 0.0001), trabecular width was also increased overall in the cases by 52% (P < 0.001), as was cancellous connectivity measured by strut analysis (P < 0.01). Where osteophytic bone was present (n = 9) there was a positive relationship between the amount of osteophyte and the percentage of cancellous area (P < 0.05). Since cancellous bone buttresses and stiffens the cortex so reducing the risk of buckling, the increased cancellous bone mass and connectivity seen in cases of cOA probably explain, at least in part, the ability of patients with cOA to resist intracapsular fracture of the femoral neck during a fall.
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Affiliation(s)
- G R Jordan
- Bone Research Group (MRC), Department of Medicine, (Box 157), University of Cambridge Clinical School, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
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Bell KL, Eissa H, Moiseiwitsch BL. First-order exchange approximation: the excitation of the 23S and 23P states of helium by electron impact. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0370-1328/88/1/307] [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: 11/12/2022]
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Littlewood RA, White MS, Bell KL, Davies PSW, Cleghorn GJ, Grote R. Comparison of the Cosmed K4 b(2) and the Deltatrac II metabolic cart in measuring resting energy expenditure in adults. Clin Nutr 2002; 21:491-7. [PMID: 12468369 DOI: 10.1054/clnu.2002.0580] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND AIMS The objective of the study was to compare data obtained from the Cosmed K4 b(2) and the Deltatrac II metabolic cart for the purpose of determining the validity of the Cosmed K4 b(2) in measuring resting energy expenditure. METHODS Nine adult subjects (four male, five female) were measured. Resting energy expenditure was measured in consecutive sessions using the Cosmed K4 b(2), the Deltatrac II metabolic cart separately and the Cosmed K4 b(2) and Deltatrac II metabolic cart simultaneously, performed in random order. Resting energy expenditure (REE) data from both devices were then compared with values obtained from predictive equations. RESULTS Bland and Altman analysis revealed a mean bias for the four variables, REE, respiratory quotient (RQ), V CO(2), V O(2) between data obtained from Cosmed K4 b(2) and Deltatrac II metabolic cart of 268+/-702 kcal/day, -0.0+/-0.2, 26.4+/-118.2 and 51.6+/-126.5 ml/min, respectively. Corresponding limits of agreement for the same four variables were all large. Also, Bland and Altman analysis revealed a larger mean bias between predicted REE and measured REE using Cosmed K4 b(2) data (-194+/-603 kcal/day) than using Deltatrac metabolic cart data (73+/-197 kcal/day). CONCLUSIONS Variability between the two devices was very high and a degree of measurement error was detected. Data from the Cosmed K4 b(2) provided variable results on comparison with predicted values, thus, would seem an invalid device for measuring adults.
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Affiliation(s)
- R A Littlewood
- Department of Paediatrics and Child Health, University of Queensland, Australia
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Bell KL, Dose V, Kingston AE. First Born approximation cross sections for electron loss from fast hydrogen atoms passing through atomic helium and fast helium atoms passing through atomic hydrogen and helium. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0022-3700/2/8/302] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bell KL, Kennedy DJ, Kingston AE. Accurate first Born approximation cross sections for the excitation of helium by fast protons. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0022-3700/1/6/305] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bell KL, Kennedy DJ, Kingston AE. Born cross sections for the electron and proton excitation of helium calculated using unrestricted Hartree-Fock wave functions. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0022-3700/1/6/304] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bell KL, Kennedy DJ, Kingston AE. Accurate first Born approximation cross sections for the excitation of helium by fast electrons. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0022-3700/2/1/307] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bell KL, Loveridge N, Reeve J, Thomas CD, Feik SA, Clement JG. Super-osteons (remodeling clusters) in the cortex of the femoral shaft: influence of age and gender. Anat Rec 2001; 264:378-86. [PMID: 11745093 DOI: 10.1002/ar.10014] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previous studies of cortical remodeling in the fractured femoral neck indicated that the merging of spatially clustered remodeling osteons could result in the formation of deleteriously large cavities associated with femoral neck fracture. This study aimed to identify whether remodeling osteons in the femoral shaft were also clustered and to assess the influence of age and gender. Microradiographic images of femoral mid-shaft cross-sections from 66 subjects over 21 years of age were analyzed to determine the number, size and location of all Haversian canals. Those most recently remodeled were identified using an edge-detection algorithm highlighting the most marked differential gradients in grey levels. Cluster analysis (JMP software) of these osteons identified the proportion of recently remodeled osteons that were within 0.75 mm clusters. As in the femoral neck, remodeling osteons were significantly more clustered than could occur by chance (real, 59.4%; random, 39.4%; P < 0.0001). The density of these clusters (number/mm(2)) was not significantly associated with subject age or gender but was greatest near the periosteum and decreased toward the marrow cavity (periosteal 0.043 +/- 0.004; mid-cortex 0.028 +/- 0.003; endosteal 0.017 +/- 0.002). Cortical porosity increased with age. The presence of giant canals (diameter >385 microm) was inversely related to the presence of clusters (R(2) = 0.237, P < 0.0001). This data suggest that remodeling osteons tend to be spatially colocalized in the shaft as they are in the neck of the femur and their presence is independent of age or gender. We propose that these remodeling clusters be termed super-osteons. The negative relationship between super-osteons and giant canals raises the intriguing possibility that loss of the control of remodeling depth results in the merging of osteonal systems to form deleteriously large cortical cavities with a marked reduction in bone strength.
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Affiliation(s)
- K L Bell
- Bone Research Group (MRC), Department of Medicine, University of Cambridge, Cambridge, United Kingdom
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