78 results on '"Nielsen DM"'
Search Results
2. Genomic Hotspots for Adaptation: The Population Genetics of Mullerian Mimicry in Heliconius erato
- Author
-
Nachman, MW, Counterman, BA, Araujo-Perez, F, Hines, HM, Baxter, SW, Morrison, CM, Lindstrom, DP, Papa, R, Ferguson, L, Joron, M, Ffrench-Constant, RH, Smith, CP, Nielsen, DM, Chen, R, Jiggins, CD, Reed, RD, Halder, G, Mallet, J, McMillan, WO, Nachman, MW, Counterman, BA, Araujo-Perez, F, Hines, HM, Baxter, SW, Morrison, CM, Lindstrom, DP, Papa, R, Ferguson, L, Joron, M, Ffrench-Constant, RH, Smith, CP, Nielsen, DM, Chen, R, Jiggins, CD, Reed, RD, Halder, G, Mallet, J, and McMillan, WO
- Abstract
Wing pattern evolution in Heliconius butterflies provides some of the most striking examples of adaptation by natural selection. The genes controlling pattern variation are classic examples of Mendelian loci of large effect, where allelic variation causes large and discrete phenotypic changes and is responsible for both convergent and highly divergent wing pattern evolution across the genus. We characterize nucleotide variation, genotype-by-phenotype associations, linkage disequilibrium (LD), and candidate gene expression patterns across two unlinked genomic intervals that control yellow and red wing pattern variation among mimetic forms of Heliconius erato. Despite very strong natural selection on color pattern, we see neither a strong reduction in genetic diversity nor evidence for extended LD across either patterning interval. This observation highlights the extent that recombination can erase the signature of selection in natural populations and is consistent with the hypothesis that either the adaptive radiation or the alleles controlling it are quite old. However, across both patterning intervals we identified SNPs clustered in several coding regions that were strongly associated with color pattern phenotype. Interestingly, coding regions with associated SNPs were widely separated, suggesting that color pattern alleles may be composed of multiple functional sites, conforming to previous descriptions of these loci as "supergenes." Examination of gene expression levels of genes flanking these regions in both H. erato and its co-mimic, H. melpomene, implicate a gene with high sequence similarity to a kinesin as playing a key role in modulating pattern and provides convincing evidence for parallel changes in gene regulation across co-mimetic lineages. The complex genetic architecture at these color pattern loci stands in marked contrast to the single casual mutations often identified in genetic studies of adaptation, but may be more indicative of the type of genet
- Published
- 2010
3. Attention deficit hyperactivity disorder and sensory modulation disorder: A comparison of behavior and physiology.
- Author
-
Miller LJ, Nielsen DM, and Schoen SA
- Published
- 2012
4. Genetic polymorphisms and the risk of stroke after cardiac surgery.
- Author
-
Grocott HP, White WD, Morris RW, Podgoreanu MV, Mathew JP, Nielsen DM, Schwinn DA, Newman MF, Grocott, Hilary P, White, William D, Morris, Richard W, Podgoreanu, Mihai V, Mathew, Joseph P, Nielsen, Dahlia M, Schwinn, Debra A, Newman, Mark F, and Perioperative Genetics and Safety Outcomes Study (PEGASUS) Investigative Team
- Published
- 2005
- Full Text
- View/download PDF
5. Navigating the maze of breast cancer treatment.
- Author
-
Meyer PJ and Nielsen DM
- Published
- 1997
6. Parental behavior and adolescent self-esteem in clinical and nonclinical samples.
- Author
-
Nielsen DM and Metha A
- Abstract
This study investigated the relationships between multiple dimensions of self-esteem and adolescents' perceptions of parental behaviors using nonclinical (n = 119) and clinical (n = 30) samples of adolescents. The Rosenberg Self-Esteem Scale (RSES), a modified version of Osgood's Semantic Differential (OSD), Schaefer's Children's Report of Parental Behavior Inventory (CRPBI) short form), and a demographic questionnaire were administered to participants. Scores from the self-esteem measures were empirically combined and factor analyzed, yielding four dimensions of self-esteem. Multivariate analysis of variance were used to compare self-esteem dimension scores for males and females within both samples. Correlations and partial correlations were conducted to determine the nature of the relationships between each dimension of self-esteem and perceptions of parental behaviors. Nonclinical adolescents scored higher than did clinical adolescents on all self-esteem dimensions. Males scored higher than females only on the dimension of Self-Esteem Competence. Perceptions of parental behaviors were consistently unrelated to dimensions of self-esteem among adolescents in the clinical sample. Among adolescents in the nonclinical sample, perceptions of parental support and autonomy granting were related to multiple dimensions of self-esteem. Perceptions of parental discipline were inconsistently related to dimensions of nonclinical self-esteem. [ABSTRACT FROM AUTHOR]
- Published
- 1994
7. Bayesian analysis of the rate of spontaneous malignant mesothelioma among BAP1 mutant mice in the absence of asbestos exposure.
- Author
-
Nielsen DM, Hsu M, Zapata M 3rd, Ciavarra G, and van Zyl L
- Subjects
- Animals, Mice, Germ-Line Mutation, Lung Neoplasms genetics, Lung Neoplasms pathology, Lung Neoplasms chemically induced, Ubiquitin Thiolesterase genetics, Asbestos toxicity, Asbestos adverse effects, Bayes Theorem, Mesothelioma, Malignant genetics, Mesothelioma, Malignant pathology, Tumor Suppressor Proteins genetics
- Abstract
Cancers of the mesothelium, such as malignant mesothelioma (MM), historically have been attributed solely to exposure to asbestos. Recent large scale genetic and genomic functional studies now show that approximately 20% of all human mesotheliomas are causally linked to highly penetrant inherited (germline) pathogenic mutations in numerous cancer related genes. The rarity of these mutations in humans makes it difficult to perform statistically conclusive genetic studies to understand their biological effects. This has created a disconnect between functional and epidemiological studies. However, since the molecular pathogenesis of MM in mice accurately recapitulates that of human disease, this disconnect between functional and epidemiological studies can be overcome by using inbred mouse strains that harbor mutation(s) in genes involved in the disease. Most mouse studies have focused on the effect of asbestos exposure, leaving the effects of genetic mutations in the absence of exposure understudied. Here, using existing peer-reviewed studies, we investigate the rate of spontaneous MM among mice with and without germline genetic mutations, in the absence of asbestos exposure. We leveraged these published data to generate a historical control dataset (HCD) to allow us to improve statistical power and account for genetic heterogeneity between studies. Our Bayesian analyses indicate that the odds of spontaneous MM among germline BAP1 mutant mice is substantially larger than that of wildtype mice. These results support the existing biological study findings that mesotheliomas can arise in the presence of pathogenic germline mutations, independently of asbestos exposure., Competing Interests: Declarations. Competing interests: DMN declares no competing interests. MH, MZ and LvZ are employees of ArrayXpress Inc., which is a genomics company that provides research and scientific expert witness consultation in civil tort cases, among other services. LvZ serves as an expert witness in personal injury litigation. GC is an employee of Lumanity Clinical and Regulatory, which is a consultative company providing research and expert services in legal matters., (© 2024. The Author(s).)
- Published
- 2025
- Full Text
- View/download PDF
8. Phenotype variability in diet-induced obesity and response to (-)-epigallocatechin gallate supplementation in a Diversity Outbred mouse cohort: A model for exploring gene x diet interactions for dietary bioactives.
- Author
-
Sweet MG, Iglesias-Carres L, Ellsworth PN, Carter JD, Nielsen DM, Aylor DL, Tessem JS, and Neilson AP
- Subjects
- Animals, Male, Mice, Dietary Supplements, Gene-Environment Interaction, Disease Models, Animal, Animals, Outbred Strains, Longitudinal Studies, Catechin analogs & derivatives, Catechin pharmacology, Catechin administration & dosage, Obesity genetics, Diet, High-Fat, Phenotype, Body Composition drug effects
- Abstract
The flavan-3-ol (-)-epigallocatechin gallate (EGCG) blunts obesity in inbred mice, but human clinical trials have yielded mixed results. Genetic homogeneity in preclinical models may explain translational disconnect between rodents and humans. The Diversity Outbred (DO) mouse model provides genotype and phenotype variability for characterization of gene x environment (i.e., diet) interactions. We conducted a longitudinal phenotyping study in DO mice. Mice (n = 50) were fed a high-fat diet for 8 weeks and then a high-fat diet + 0.3% EGCG for 8 weeks. We hypothesized that obesity and any protective effects of EGCG would exhibit extreme variability in these genetically heterogeneous mice. As anticipated, DO mice exhibited extreme variation in body composition at baseline (4%-13.9% fat), after 8 weeks of high-fat diet (6.5%-38.1% fat), and after 8 weeks of high-fat diet + EGCG (7.6%-42.6% fat), greater than what is observed in inbred mice. All 50 mice gained body fat on the high-fat diet (changes from baseline of +5% ± 640%). Intriguingly, adiposity variability increased when EGCG was added to the diet (changes from the high-fat diet alone of -52% ± 390%), with 11/50 mice losing body fat. We postulate that the explanation for this variability is genetic heterogeneity. Our data confirm the promise for EGCG to manage obesity but suggest that genetic factors may exert significant control over the efficacy of EGCG. Larger studies in DO mice are needed for quantitative trait loci mapping to identify genetic loci governing EGCG x obesity interactions and translate these findings to precision nutrition in humans., Competing Interests: Author declarations None., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
9. Permafrost thaw subsidence, sea-level rise, and erosion are transforming Alaska's Arctic coastal zone.
- Author
-
Creel R, Guimond J, Jones BM, Nielsen DM, Bristol E, Tweedie CE, and Overduin PP
- Abstract
Arctic shorelines are vulnerable to climate change impacts as sea level rises, permafrost thaws, storms intensify, and sea ice thins. Seventy-five years of aerial and satellite observations have established coastal erosion as an increasing Arctic hazard. However, other hazards at play-for instance, the cumulative impact that sea-level rise and permafrost thaw subsidence will have on permafrost shorelines-have received less attention, preventing assessments of these processes' impacts compared to and combined with coastal erosion. Alaska's Arctic Coastal Plain (ACP) is ideal for such assessments because of the high-density observations of topography, coastal retreat rates, and permafrost characteristics, and importance to Indigenous communities and oilfield infrastructure. Here, we produce 21st-century projections of Arctic shoreline position that include erosion, permafrost subsidence, and sea-level rise. Focusing on the ACP, we merge 5 m topography, satellite-derived coastal lake depth estimates, and empirical assessments of land subsidence due to permafrost thaw with projections of coastal erosion and sea-level rise for medium and high emissions scenarios from the Intergovernmental Panel on Climate Change's AR6 Report. We find that by 2100, erosion and inundation will together transform the ACP, leading to 6-8x more land loss than coastal erosion alone and disturbing 8-11x more organic carbon. Without mitigating measures, by 2100, coastal change could damage 40 to 65% of infrastructure in present-day ACP coastal villages and 10 to 20% of oilfield infrastructure. Our findings highlight the risks that compounding climate hazards pose to coastal communities and underscore the need for adaptive planning for Arctic coastlines in the 21st century., Competing Interests: Competing interests statement:The authors declare no competing interest.
- Published
- 2024
- Full Text
- View/download PDF
10. Degree of hydrolysis is a poor predictor of the sensitizing capacity of whey- and casein-based hydrolysates in a Brown Norway rat model of cow's milk allergy.
- Author
-
Bøgh KL, Nielsen DM, Mohammad-Beigi H, Christoffersen HF, Jacobsen LN, Norrild RK, Svensson B, Schmidthaler K, Szépfalusi Z, Upton J, Eiwegger T, Bertelsen H, Buell AK, Sørensen LV, and Larsen JM
- Subjects
- Humans, Animals, Cattle, Female, Infant, Rats, Caseins, Hydrolysis, Protein Hydrolysates, Whey Proteins, Milk Proteins, Immunoglobulin G, Peptides, Immunoglobulin E, Whey, Milk Hypersensitivity prevention & control
- Abstract
The use of infant formulas (IFs) based on hydrolyzed cow's milk proteins to prevent cow's milk allergy (CMA) is highly debated. The risk of sensitization to milk proteins induced by IFs may be affected by the degree of hydrolysis (DH) as well as other physicochemical properties of the cow's milk-based protein hydrolysates within the IFs. The immunogenicity (specific IgG1 induction) and sensitizing capacity (specific IgE induction) of 30 whey- or casein-based hydrolysates with different physicochemical characteristics were compared using an intraperitoneal model of CMA in Brown Norway rats. In general, the whey-based hydrolysates demonstrated higher immunogenicity than casein-based hydrolysates, inducing higher levels of hydrolysate-specific and intact-specific IgG1. The immunogenicity of the hydrolysates was influenced by DH, peptide size distribution profile, peptide aggregation, nano-sized particle formation, and surface hydrophobicity. Yet, only the surface hydrophobicity was found to affect the sensitizing capacity of hydrolysates, as high hydrophobicity was associated with higher levels of specific IgE. The whey- and casein-based hydrolysates exhibited distinct immunological properties with highly diverse molecular composition and physicochemical properties which are not accounted for by measuring DH, which was a poor predictor of sensitizing capacity. Thus, future studies should consider and account for physicochemical characteristics when assessing the sensitizing capacity of cow's milk-based protein hydrolysates., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: DMN, HFC, LNJ, HB, and LVS are employees at Arla Foods Ingredients. KLB has ongoing collaboration with and received funding from the company Arla Foods Ingredients. The other authors declare no conflict of interest. The funding agency played no role in study design, data acquisition, data analysis, interpretation, manuscript preparation, or the decision to publish., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
11. Comparison of 16 Serological SARS-CoV-2 Immunoassays in 16 Clinical Laboratories.
- Author
-
Harritshøj LH, Gybel-Brask M, Afzal S, Kamstrup PR, Jørgensen CS, Thomsen MK, Hilsted L, Friis-Hansen L, Szecsi PB, Pedersen L, Nielsen L, Hansen CB, Garred P, Korsholm TL, Mikkelsen S, Nielsen KO, Møller BK, Hansen AT, Iversen KK, Nielsen PB, Hasselbalch RB, Fogh K, Norsk JB, Kristensen JH, Schønning K, Kirkby NS, Nielsen ACY, Landsy LH, Loftager M, Holm DK, Nilsson AC, Sækmose SG, Grum-Schwensen B, Aagaard B, Jensen TG, Nielsen DM, Ullum H, and Dessau RB
- Subjects
- Cytomegalovirus Infections, Enzyme-Linked Immunosorbent Assay, Epstein-Barr Virus Infections, Herpesvirus 4, Human, Humans, Immunoglobulin G isolation & purification, Immunoglobulin M isolation & purification, Laboratories, SARS-CoV-2, Sensitivity and Specificity, Antibodies, Viral isolation & purification, COVID-19 diagnosis, COVID-19 Serological Testing methods, Immunoassay
- Abstract
Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for large-scale detection of total antibodies (Ab), immunoglobulin G (IgG), and IgM against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays. This study was a Danish national collaboration and evaluated 15 commercial and one in-house anti-SARS-CoV-2 assays in 16 laboratories. Sensitivity was evaluated using 150 samples from individuals with asymptomatic, mild, or moderate COVID-19, nonhospitalized or hospitalized, confirmed by nucleic acid amplification tests (NAAT); samples were collected 13 to 73 days either from symptom onset or from positive NAAT (patients without symptoms). Specificity and cross-reactivity were evaluated in samples collected prior to the SARS-CoV-2 epidemic from >586 blood donors and patients with autoimmune diseases, cytomegalovirus or Epstein-Barr virus infections, and acute viral infections. A specificity of ≥99% was achieved by all total-Ab and IgG assays except one, DiaSorin Liaison XL IgG (97.2%). Sensitivities in descending order were Wantai ELISA total Ab (96.7%), CUH-NOVO in-house ELISA total Ab (96.0%), Ortho Vitros total Ab (95.3%), YHLO iFlash IgG (94.0%), Ortho Vitros IgG (93.3%), Siemens Atellica total Ab (93.2%), Roche Elecsys total Ab (92.7%), Abbott Architect IgG (90.0%), Abbott Alinity IgG (median 88.0%), DiaSorin Liaison XL IgG (median 84.6%), Siemens Vista total Ab (81.0%), Euroimmun/ELISA IgG (78.0%), and Snibe Maglumi IgG (median 78.0%). However, confidence intervals overlapped for several assays. The IgM results were variable, with the Wantai IgM ELISA showing the highest sensitivity (82.7%) and specificity (99%). The rate of seropositivity increased with time from symptom onset and symptom severity., (Copyright © 2021 American Society for Microbiology.)
- Published
- 2021
- Full Text
- View/download PDF
12. Interferon-λ3 Promotes Epithelial Defense and Barrier Function Against Cryptosporidium parvum Infection.
- Author
-
Ferguson SH, Foster DM, Sherry B, Magness ST, Nielsen DM, and Gookin JL
- Subjects
- Animals, Cell Line, Cryptosporidiosis genetics, Cryptosporidiosis parasitology, Cytokines metabolism, Disease Models, Animal, Gene Expression Profiling, Mice, Mice, Inbred C57BL, Oligonucleotide Array Sequence Analysis, Swine, Cryptosporidiosis immunology, Cryptosporidium parvum physiology, Cytokines genetics, Intestinal Mucosa immunology, Up-Regulation
- Abstract
Background & Aims: The epithelial response is critical for intestinal defense against Cryptosporidium, but is poorly understood. To uncover the host strategy for defense against Cryptosporidium, we examined the transcriptional response of intestinal epithelial cells (IECs) to C parvum in experimentally infected piglets by microarray. Up-regulated genes were dominated by targets of interferon (IFN) and IFN-λ3 was up-regulated significantly in infected piglet mucosa. Although IFN-λ has been described as a mediator of epithelial defense against viral pathogens, there is limited knowledge of any role against nonviral pathogens. Accordingly, the aim of the study was to determine the significance of IFN-λ3 to epithelial defense and barrier function during C parvum infection., Methods: The significance of C parvum-induced IFN-λ3 expression was determined using an immunoneutralization approach in neonatal C57BL/6 mice. The ability of the intestinal epithelium to up-regulate IFN-λ2/3 expression in response to C parvum infection and the influence of IFN-λ2/3 on epithelial defense against C parvum invasion, intracellular development, and loss of barrier function was examined using polarized monolayers of a nontransformed porcine-derived small intestinal epithelial cell line (IPEC-J2). Specifically, changes in barrier function were quantified by measurement of transepithelial electrical resistance and transepithelial flux studies., Results: Immunoneutralization of IFN-λ2/3 in C parvum-infected neonatal mice resulted in a significantly increased parasite burden, fecal shedding, and villus blunting with crypt hyperplasia during peak infection. In vitro, C parvum was sufficient to induce autonomous IFN-λ3 and interferon-stimulated gene 15 expression by IECs. Priming of IECs with recombinant human IFN-λ3 promoted cellular defense against C parvum infection and abrogated C parvum-induced loss of barrier function by decreasing paracellular permeability to sodium., Conclusions: These studies identify IFN-λ3 as a key epithelial defense mechanism against C parvum infection., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
13. Networks Underpinning Symbiosis Revealed Through Cross-Species eQTL Mapping.
- Author
-
Guo Y, Fudali S, Gimeno J, DiGennaro P, Chang S, Williamson VM, Bird DM, and Nielsen DM
- Subjects
- Animals, Chromosome Mapping methods, Genetic Pleiotropy, Helminth Proteins genetics, Helminth Proteins metabolism, Medicago parasitology, Plant Proteins genetics, Plant Proteins metabolism, Polymorphism, Genetic, Transcription Factors genetics, Transcription Factors metabolism, Tylenchoidea pathogenicity, Gene Regulatory Networks, Medicago genetics, Quantitative Trait Loci, Symbiosis genetics, Tylenchoidea genetics
- Abstract
Organisms engage in extensive cross-species molecular dialog, yet the underlying molecular actors are known for only a few interactions. Many techniques have been designed to uncover genes involved in signaling between organisms. Typically, these focus on only one of the partners. We developed an expression quantitative trait locus (eQTL) mapping-based approach to identify cause-and-effect relationships between genes from two partners engaged in an interspecific interaction. We demonstrated the approach by assaying expression of 98 isogenic plants ( Medicago truncatula ), each inoculated with a genetically distinct line of the diploid parasitic nematode Meloidogyne hapla With this design, systematic differences in gene expression across host plants could be mapped to genetic polymorphisms of their infecting parasites. The effects of parasite genotypes on plant gene expression were often substantial, with up to 90-fold ( P = 3.2 × 10
-52 ) changes in expression levels caused by individual parasite loci. Mapped loci included a number of pleiotropic sites, including one 87-kb parasite locus that modulated expression of >60 host genes. The 213 host genes identified were substantially enriched for transcription factors. We distilled higher-order connections between polymorphisms and genes from both species via network inference. To replicate our results and test whether effects were conserved across a broader host range, we performed a confirmatory experiment using M. hapla -infected tomato. This revealed that homologous genes were similarly affected. Finally, to validate the broader utility of cross-species eQTL mapping, we applied the strategy to data from a Salmonella infection study, successfully identifying polymorphisms in the human genome affecting bacterial expression., (Copyright © 2017 by the Genetics Society of America.)- Published
- 2017
- Full Text
- View/download PDF
14. Genetics of Hereditary Ataxia in Scottish Terriers.
- Author
-
Urkasemsin G, Nielsen DM, Singleton A, Arepalli S, Hernandez D, Agler C, and Olby NJ
- Subjects
- Animals, Brain diagnostic imaging, Dog Diseases diagnostic imaging, Dogs, Female, Genetic Linkage genetics, Genome-Wide Association Study veterinary, Homozygote, Magnetic Resonance Imaging veterinary, Male, Neuroimaging veterinary, Pedigree, Spinocerebellar Degenerations diagnostic imaging, Spinocerebellar Degenerations genetics, Dog Diseases genetics, Spinocerebellar Degenerations veterinary
- Abstract
Background: Scottish Terriers have a high incidence of juvenile onset hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex and causing slowly progressive cerebellar dysfunction., Objective: To identify chromosomal regions associated with hereditary ataxia in Scottish Terriers., Animals: One hundred and fifty-three Scottish Terriers were recruited through the Scottish Terrier Club of America., Materials and Methods: Prospective study. Dogs were classified as affected if they had slowly progressive cerebellar signs. When possible, magnetic resonance imaging and histopathological evaluation of the brain were completed as diagnostic aids. To identify genomic regions connected with the disease, genome-wide mapping was performed using both linkage- and association-based approaches. Pedigree evaluation and homozygosity mapping were also performed to examine mode of inheritance and to investigate the region of interest, respectively., Results: Linkage and genome-wide association studies in a cohort of Scottish Terriers both identified a region on CFA X strongly associated with the disease trait. Homozygosity mapping revealed a 4 Mb region of interest. Pedigree evaluation failed to identify the possible mode of inheritance due to the lack of complete litter information., Conclusion and Clinical Importance: This finding suggests that further genetic investigation of the potential region of interest on CFA X should be considered in order to identify the causal mutation as well as develop a genetic test to eliminate the disease from this breed., (Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)
- Published
- 2017
- Full Text
- View/download PDF
15. Surgical fixation methods for tibial plateau fractures.
- Author
-
McNamara IR, Smith TO, Shepherd KL, Clark AB, Nielsen DM, Donell S, and Hing CB
- Subjects
- Adult, Bone Substitutes therapeutic use, Bone Transplantation, Female, Fracture Fixation, Internal methods, Humans, Male, Quality of Life, Randomized Controlled Trials as Topic, Fracture Fixation methods, Tibial Fractures surgery
- Abstract
Background: Fractures of the tibial plateau, which are intra-articular injuries of the knee joint, are often difficult to treat and have a high complication rate, including early-onset osteoarthritis. Surgical fixation is usually used for more complex tibial plateau fractures. Additionally, bone void fillers are often used to address bone defects caused by the injury. Currently there is no consensus on either the best method of fixation or bone void filler., Objectives: To assess the effects (benefits and harms) of different surgical interventions, and the use of bone void fillers, for treating tibial plateau fractures., Search Methods: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (12 September 2014), the Cochrane Central Register of Controlled Trials (2014 Issue 8), MEDLINE (1946 to September Week 1 2014), EMBASE (1974 to 2014 Week 36), trial registries (4 July 2014), conference proceedings and grey literature (4 July 2014)., Selection Criteria: We included randomised and quasi-randomised controlled clinical trials comparing surgical interventions for treating tibial plateau fractures and the different types of filler for filling bone defects., Data Collection and Analysis: Two review authors independently screened search results, selected studies, extracted data and assessed risk of bias. We calculated risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CIs). Only very limited pooling, using the fixed-effect model, was possible. Our primary outcomes were quality of life measures, patient-reported outcome measures of lower limb function and serious adverse events., Main Results: We included six trials in the review, with a total of 429 adult participants, the majority of whom were male (63%). Three trials evaluated different types of fixation and three analysed different types of bone graft substitutes. All six trials were small and at substantial risk of bias. We judged the quality of most of the available evidence to be very low, meaning that we are very uncertain about these results.One trial compared the use of a circular fixator combined with insertion of percutaneous screws (hybrid fixation) versus standard open reduction and internal fixation (ORIF) in people with open or closed Schatzker types V or VI tibial plateau fractures. Results (66 participants) for quality of life scores using the 36-item Short Form Health Survey (SF-36)), Hospital for Special Surgery (HSS) scores and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scores tended to favour hybrid fixation, but a benefit of ORIF could not be ruled out. Participants in the hybrid fixation group had a lower risk for an unplanned reoperation (351 per 1000 people compared with 450 in the ORIF group; 95% CI 197 fewer to 144 more) and were more likely to have returned to their pre-injury activity level (303 per 1000 people, compared with 121 in the ORIF group; 95% CI 15 fewer to 748 more). Results of the two groups were comparable for the WOMAC pain subscale and stiffness scores, but mean knee range of motion values were higher in the hybrid group.Another trial compared the use of a minimally invasive plate (LISS system) versus double-plating ORIF in 84 people who had open or closed bicondylar tibial plateau fractures. Nearly twice as many participants (22 versus 12) in the ORIF group had a bone graft. Quality of life, pain, knee range of motion and return to pre-injury activity were not reported. The trial provided no evidence of differences in HSS knee scores, complications or reoperation entailing implant removal or revision fixation. A quasi-randomised trial comparing arthroscopically-assisted percutaneous reduction and internal fixation versus standard ORIF reported results at 14 months in 58 people with closed Schatzker types II or III tibial plateau fracture. Quality of life, pain and return to pre-injury activity were not reported. There was very low quality evidence of higher HSS knee scores and higher knee range of motion values in the arthroscopically assisted group. No reoperations were reported.Three trials compared different types of bone substitute versus autologous bone graft (autograft) for managing bone defects. Quality of life, pain and return to pre-injury activity were not reported. Only one trial (25 participants) reported on lower limb function, finding good or excellent results in both groups for walking, climbing stairs, squatting and jumping at 12 months. The incidences of individual complications were similar between groups in all three trials. One trial found no cases of inflammatory response in the 20 participants receiving bone substitute, and two found no complications associated with the donor site in the autograft group (58 participants). However, all 38 participants in the autologous iliac bone graft group of one trial reported prolonged pain from the harvest site. Two trials reported similar range of motion results in the two groups, whereas the third trial favoured the bone substitute group., Authors' Conclusions: Currently, there is insufficient evidence to ascertain the best method of fixation or the best method of addressing bone defects during surgery. However, the evidence does not contradict approaches aiming to limit soft-tissue dissection and damage or to avoid autograft donor site complications through using bone substitutes. Further well-designed, larger randomised trials are warranted.
- Published
- 2015
- Full Text
- View/download PDF
16. Increased exposure to acute thermal stress is associated with a non-linear increase in recombination frequency and an independent linear decrease in fitness in Drosophila.
- Author
-
Jackson S, Nielsen DM, and Singh ND
- Subjects
- Animals, Biological Evolution, Drosophila melanogaster cytology, Drosophila melanogaster genetics, Meiosis, Recombination, Genetic, Drosophila melanogaster physiology, Heat-Shock Response
- Abstract
Background: Meiotic recombination rate has long been known to be phenotypically plastic. How plastic recombination evolves and is maintained remains controversial; though a leading model for the evolution of plastic recombination rests on the tenet that organismal fitness and recombination frequency are negatively correlated. Motivated by the mounting evidence that meiotic recombination frequencies increase in response to stress, here we test for a negative correlation between fitness and recombination frequency. Specifically, the fitness-associated recombination model (FAR) predicts that if stress increases meiotic recombination frequency, then increasing exposure to stressful conditions will yield an increasing magnitude of the recombinational response, while concomitantly decreasing fitness., Results: We use heat shock as a stressor to test this prediction in Drosophila melanogaster. We find that increased exposure to heat shock conditions is associated with a non-linear increase in meiotic recombination frequency. We also find an independent effect of heat shock on organismal fitness, with fitness decreasing with increased duration of thermal stress., Conclusions: Our results thus support the foundation of the FAR model for the evolution of plastic recombination. Our data also suggest that modulating recombination frequency is one mechanism by which organisms can rapidly respond to environmental cues and confer increased adaptive potential to their offspring.
- Published
- 2015
- Full Text
- View/download PDF
17. Factors Influencing Production of Fusaristatin A in Fusarium graminearum.
- Author
-
Hegge A, Lønborg R, Nielsen DM, and Sørensen JL
- Abstract
Fusarium graminearum is a ubiquitous plant pathogen, which is able to produce several bioactive secondary metabolites. Recently, the cyclic lipopeptide fusaristatin A was isolated from this species and the biosynthetic gene cluster identified. Fusaristatin A consists of a C24 reduced polyketide and the three amino acids dehydroalanine, β-aminoisobutyric acid and glutamine and is biosynthesized by a collaboration of a polyketide synthase and a nonribosomal peptide synthetase. To gain insight into the environmental factors, which controls the production of fusaristatin A, we cultivated F. graminearum under various conditions. We developed an LC-MS/MS method to quantify fusaristatin A in F. graminearum extracts. The results showed that yeast extract sucrose (YES) medium was the best medium for fusaristatin A production and that the optimal pH was 7.5 and temperature 25-30 °C. Furthermore, production of fusaristatin A was more than four times higher in stationary cultures than in agitated cultures when F. graminearum was grown in liquid YES medium. The results also showed that fusaristatin A was only present in the mycelium and not in the liquid, which suggests that fusaristatin A is stored intracellulally and not exported to the extracellular environment.
- Published
- 2015
- Full Text
- View/download PDF
18. The presence of migraines and its association with sensory hyperreactivity and anxiety symptomatology in children with autism spectrum disorder.
- Author
-
Sullivan JC, Miller LJ, Nielsen DM, and Schoen SA
- Subjects
- Adolescent, Anxiety epidemiology, Anxiety Disorders epidemiology, Child, Child Development Disorders, Pervasive epidemiology, Comorbidity, Female, Humans, Male, Migraine Disorders epidemiology, Pilot Projects, Sensation Disorders epidemiology, Anxiety psychology, Anxiety Disorders psychology, Child Development Disorders, Pervasive psychology, Migraine Disorders psychology, Sensation Disorders psychology
- Abstract
Migraine headaches are associated with sensory hyperreactivity and anxiety in the general population, but it is unknown whether this is also the case in autism spectrum disorders. This pilot study asked parents of 81 children (aged 7-17 years) with autism spectrum disorders to report their child's migraine occurrence, sensory hyperreactivity (Sensory Over-Responsivity Inventory), and anxiety symptoms (Spence Child Anxiety Scale). Children with autism spectrum disorders who experienced migraine headaches showed greater sensory hyperreactivity and anxiety symptomatology (p < 0.01; medium effect size for both) than those without migraines. Sensory hyperreactivity and anxiety symptomatology were additionally correlated (ρ = 0.31, p = 0.005). This study provides preliminary evidence for a link between migraine headaches, sensory hyperreactivity, and anxiety symptomatology in autism spectrum disorders, which may suggest strategies for subtyping and exploring a common pathogenesis., (© The Author(s) 2013.)
- Published
- 2014
- Full Text
- View/download PDF
19. Aspergillus flavus infection induces transcriptional and physical changes in developing maize kernels.
- Author
-
Dolezal AL, Shu X, OBrian GR, Nielsen DM, Woloshuk CP, Boston RS, and Payne GA
- Abstract
Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understanding host response to infection by the fungus, transcription of approximately 9000 maize genes were monitored during the host-pathogen interaction with a custom designed Affymetrix GeneChip® DNA array. More than 4000 maize genes were found differentially expressed at a FDR of 0.05. This included the up regulation of defense related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel by A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development.
- Published
- 2014
- Full Text
- View/download PDF
20. Improved structural annotation of protein-coding genes in the Meloidogyne hapla genome using RNA-Seq.
- Author
-
Guo Y, Bird DM, and Nielsen DM
- Abstract
As high-throughput cDNA sequencing (RNA-Seq) is increasingly applied to hypothesis-driven biological studies, the prediction of protein coding genes based on these data are usurping strictly in silico approaches. Compared with computationally derived gene predictions, structural annotation is more accurate when based on biological evidence, particularly RNA-Seq data. Here, we refine the current genome annotation for the Meloidogyne hapla genome utilizing RNA-Seq data. Published structural annotation defines 14 420 protein-coding genes in the M. hapla genome. Of these, 25% (3751) were found to exhibit some incongruence with RNA-Seq data. Manual annotation enabled these discrepancies to be resolved. Our analysis revealed 544 new gene models that were missing from the prior annotation. Additionally, 1457 transcribed regions were newly identified on the ends of as-yet-unjoined contigs. We also searched for trans-spliced leaders, and based on RNA-Seq data, identified genes that appear to be trans-spliced. Four 22-bp trans-spliced leaders were identified using our pipeline, including the known trans-spliced leader, which is the M. hapla ortholog of SL1. In silico predictions of trans-splicing were validated by comparison with earlier results derived from an independent cDNA library constructed to capture trans-spliced transcripts. The new annotation, which we term HapPep5, is publically available at www.hapla.org.
- Published
- 2014
- Full Text
- View/download PDF
21. Sensory over-responsivity in adults with autism spectrum conditions.
- Author
-
Tavassoli T, Miller LJ, Schoen SA, Nielsen DM, and Baron-Cohen S
- Subjects
- Adult, Analysis of Variance, Female, Humans, Male, Surveys and Questionnaires, Autistic Disorder complications, Autistic Disorder psychology, Perceptual Disorders complications, Perceptual Disorders psychology
- Abstract
Anecdotal reports and empirical evidence suggest that sensory processing issues are a key feature of autism spectrum conditions. This study set out to investigate whether adults with autism spectrum conditions report more sensory over-responsivity than adults without autism spectrum conditions. Another goal of the study was to identify whether autistic traits in adults with and without autism spectrum conditions were associated with sensory over-responsivity. Adults with (n = 221) and without (n = 181) autism spectrum conditions participated in an online survey. The Autism Spectrum Quotient, the Raven Matrices and the Sensory Processing Scale were used to characterize the sample. Adults with autism spectrum conditions reported more sensory over-responsivity than control participants across various sensory domains (visual, auditory, tactile, olfactory, gustatory and proprioceptive). Sensory over-responsivity correlated positively with autistic traits (Autism Spectrum Quotient) at a significant level across groups and within groups. Adults with autism spectrum conditions experience sensory over-responsivity to daily sensory stimuli to a high degree. A positive relationship exists between sensory over-responsivity and autistic traits. Understanding sensory over-responsivity and ways of measuring it in adults with autism spectrum conditions has implications for research and clinical settings.
- Published
- 2014
- Full Text
- View/download PDF
22. Canine hereditary ataxia in old english sheepdogs and gordon setters is associated with a defect in the autophagy gene encoding RAB24.
- Author
-
Agler C, Nielsen DM, Urkasemsin G, Singleton A, Tonomura N, Sigurdsson S, Tang R, Linder K, Arepalli S, Hernandez D, Lindblad-Toh K, van de Leemput J, Motsinger-Reif A, O'Brien DP, Bell J, Harris T, Steinberg S, and Olby NJ
- Subjects
- Animals, Cerebellar Cortex pathology, Chromosome Mapping, Dog Diseases pathology, Dogs, High-Throughput Nucleotide Sequencing, Humans, Mice, Mutation, Polymorphism, Single Nucleotide, Spinocerebellar Degenerations etiology, Autophagy genetics, Dog Diseases genetics, Genome-Wide Association Study, Spinocerebellar Degenerations genetics, rab GTP-Binding Proteins genetics
- Abstract
Old English Sheepdogs and Gordon Setters suffer from a juvenile onset, autosomal recessive form of canine hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex. The clinical and histological characteristics are analogous to hereditary ataxias in humans. Linkage and genome-wide association studies on a cohort of related Old English Sheepdogs identified a region on CFA4 strongly associated with the disease phenotype. Targeted sequence capture and next generation sequencing of the region identified an A to C single nucleotide polymorphism (SNP) located at position 113 in exon 1 of an autophagy gene, RAB24, that segregated with the phenotype. Genotyping of six additional breeds of dogs affected with hereditary ataxia identified the same polymorphism in affected Gordon Setters that segregated perfectly with phenotype. The other breeds tested did not have the polymorphism. Genome-wide SNP genotyping of Gordon Setters identified a 1.9 MB region with an identical haplotype to affected Old English Sheepdogs. Histopathology, immunohistochemistry and ultrastructural evaluation of the brains of affected dogs from both breeds identified dramatic Purkinje neuron loss with axonal spheroids, accumulation of autophagosomes, ubiquitin positive inclusions and a diffuse increase in cytoplasmic neuronal ubiquitin staining. These findings recapitulate the changes reported in mice with induced neuron-specific autophagy defects. Taken together, our results suggest that a defect in RAB24, a gene associated with autophagy, is highly associated with and may contribute to canine hereditary ataxia in Old English Sheepdogs and Gordon Setters. This finding suggests that detailed investigation of autophagy pathways should be undertaken in human hereditary ataxia.
- Published
- 2014
- Full Text
- View/download PDF
23. Localization, morphology and transcriptional profile of Aspergillus flavus during seed colonization.
- Author
-
Dolezal AL, Obrian GR, Nielsen DM, Woloshuk CP, Boston RS, and Payne GA
- Subjects
- Aspergillus flavus pathogenicity, Chromosomes, Fungal genetics, Colony Count, Microbial, DNA, Fungal isolation & purification, Electrophoresis, Agar Gel, Endosperm microbiology, Genes, Fungal genetics, Humans, Seeds cytology, Transcription Factors metabolism, Zea mays cytology, Aspergillus flavus genetics, Aspergillus flavus growth & development, Gene Expression Profiling, Gene Expression Regulation, Fungal, Seeds microbiology, Transcription, Genetic, Zea mays microbiology
- Abstract
Aspergillus flavus is an opportunistic fungal pathogen that infects maize kernels pre-harvest, creating major human health concerns and causing substantial agricultural losses. Improved control strategies are needed, yet progress is hampered by the limited understanding of the mechanisms of infection. A series of studies were designed to investigate the localization, morphology and transcriptional profile of A. flavus during internal seed colonization. Results from these studies indicate that A. flavus is capable of infecting all tissues of the immature kernel by 96 h after infection. Mycelia were observed in and around the point of inoculation in the endosperm and were found growing down to the germ. At the endosperm-germ interface, hyphae appeared to differentiate and form a biofilm-like structure that surrounded the germ. The exact nature of this structure remains unclear, but is discussed. A custom-designed A. flavus Affymetrix GeneChip® microarray was used to monitor genome-wide transcription during pathogenicity. A total of 5061 genes were designated as being differentially expressed. Genes encoding secreted enzymes, transcription factors and secondary metabolite gene clusters were up-regulated and considered to be potential effector molecules responsible for disease in the kernel. Information gained from this study will aid in the development of strategies aimed at preventing or slowing down A. flavus colonization of the maize kernel., (© 2013 BSPP AND JOHN WILEY & SONS LTD.)
- Published
- 2013
- Full Text
- View/download PDF
24. Gene profiling of canine B-cell lymphoma reveals germinal center and postgerminal center subtypes with different survival times, modeling human DLBCL.
- Author
-
Richards KL, Motsinger-Reif AA, Chen HW, Fedoriw Y, Fan C, Nielsen DM, Small GW, Thomas R, Smith C, Dave SS, Perou CM, Breen M, Borst LB, and Suter SE
- Subjects
- Adolescent, Animals, Child, Child, Preschool, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Disease Models, Animal, Dogs, Female, Gene Expression Profiling methods, Germinal Center pathology, Humans, Immunoglobulin Heavy Chains genetics, Immunoglobulin Heavy Chains metabolism, Interferon Regulatory Factors genetics, Interferon Regulatory Factors metabolism, Lymph Nodes metabolism, Lymph Nodes pathology, Lymphoma, B-Cell metabolism, Lymphoma, B-Cell pathology, Lymphoma, Large B-Cell, Diffuse metabolism, Lymphoma, Large B-Cell, Diffuse pathology, Male, Mutation, NF-kappa B genetics, NF-kappa B metabolism, Proto-Oncogene Proteins c-bcl-6, Transcriptome, Germinal Center metabolism, Lymphoma, B-Cell genetics, Lymphoma, Large B-Cell, Diffuse genetics
- Abstract
Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype, and fewer than half of patients are cured with standard first-line therapy. To improve therapeutic options, better animal models that accurately mimic human DLBCL (hDLBCL) are needed. Canine DLBCL, one of the most common cancers in veterinary oncology, is morphologically similar to hDLBCL and is treated using similar chemotherapeutic protocols. With genomic technologies, it is now possible to molecularly evaluate dogs as a potential large-animal model for hDLBCL. We evaluated canine B-cell lymphomas (cBCL) using immunohistochemistry (IHC) and gene expression profiling. cBCL expression profiles were similar in many ways to hDLBCLs. For instance, a subset had increased expression of NF-κB pathway genes, mirroring human activated B-cell (ABC)-type DLBCL. Furthermore, immunoglobulin heavy chain ongoing mutation status, which is correlated with ABC/germinal center B-cell cell of origin in hDLBCL, separated cBCL into two groups with statistically different progression-free and overall survival times. In contrast with hDLBCL, cBCL rarely expressed BCL6 and MUM1/IRF4 by IHC. Collectively, these studies identify molecular similarities to hDLBCL that introduce pet dogs as a representative model of hDLBCL for future studies, including therapeutic clinical trials.
- Published
- 2013
- Full Text
- View/download PDF
25. Genomic architecture of adaptive color pattern divergence and convergence in Heliconius butterflies.
- Author
-
Supple MA, Hines HM, Dasmahapatra KK, Lewis JJ, Nielsen DM, Lavoie C, Ray DA, Salazar C, McMillan WO, and Counterman BA
- Subjects
- Adaptation, Biological genetics, Animal Distribution, Animals, Base Sequence, Bayes Theorem, Conserved Sequence, Genetic Speciation, Genotype, Haplotypes, High-Throughput Nucleotide Sequencing, Likelihood Functions, Models, Genetic, Molecular Sequence Annotation, Molecular Sequence Data, Panama, Phenotype, Phylogeny, Sequence Analysis, DNA, South America, Synteny, Transcriptome, Wings, Animal physiology, Butterflies genetics, Evolution, Molecular, Genome, Insect, Pigmentation genetics
- Abstract
Identifying the genetic changes driving adaptive variation in natural populations is key to understanding the origins of biodiversity. The mosaic of mimetic wing patterns in Heliconius butterflies makes an excellent system for exploring adaptive variation using next-generation sequencing. In this study, we use a combination of techniques to annotate the genomic interval modulating red color pattern variation, identify a narrow region responsible for adaptive divergence and convergence in Heliconius wing color patterns, and explore the evolutionary history of these adaptive alleles. We use whole genome resequencing from four hybrid zones between divergent color pattern races of Heliconius erato and two hybrid zones of the co-mimic Heliconius melpomene to examine genetic variation across 2.2 Mb of a partial reference sequence. In the intergenic region near optix, the gene previously shown to be responsible for the complex red pattern variation in Heliconius, population genetic analyses identify a shared 65-kb region of divergence that includes several sites perfectly associated with phenotype within each species. This region likely contains multiple cis-regulatory elements that control discrete expression domains of optix. The parallel signatures of genetic differentiation in H. erato and H. melpomene support a shared genetic architecture between the two distantly related co-mimics; however, phylogenetic analysis suggests mimetic patterns in each species evolved independently. Using a combination of next-generation sequencing analyses, we have refined our understanding of the genetic architecture of wing pattern variation in Heliconius and gained important insights into the evolution of novel adaptive phenotypes in natural populations.
- Published
- 2013
- Full Text
- View/download PDF
26. Phenotypes within sensory modulation dysfunction.
- Author
-
James K, Miller LJ, Schaaf R, Nielsen DM, and Schoen SA
- Subjects
- Adolescent, Checklist, Child, Child Behavior psychology, Child, Preschool, Cluster Analysis, Emotions, Female, Humans, Male, Phenotype, Physical Stimulation, Psychiatric Status Rating Scales, Sensation Disorders physiopathology, Sensation Disorders psychology, Sensation Disorders classification
- Abstract
Sensory modulation disorder (SMD) is a severe inability to regulate responses to everyday sensory stimulation to which most people easily adapt. It is estimated to affect 5% to 16% of the general population of children. Although heterogeneity is seen in the presentation clinically, previous research has not empirically investigated whether the clinical heterogeneity of SMD can be classified into subtypes. This study explores a cohort of 98 children identified with SMD at the Department of Pediatric Rehabilitation by a member of the occupational therapy team at The Children's Hospital of Denver. Two subtypes of SMD were identified through cluster analysis based on data from 4 parent-report instruments. The first subtype is characterized by sensory seeking/craving, hyperactive, impulsive, externalizing (eg, delinquent, aggressive), unsocial, inadaptive, and impaired cognitive/social behavior. The second subtype is characterized by movement sensitivity, emotionally withdrawal, and low energy/weak behavior. Findings from this study present a step toward understanding and classifying the complexities of children with SMDs., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
27. Characterization of canine osteosarcoma by array comparative genomic hybridization and RT-qPCR: signatures of genomic imbalance in canine osteosarcoma parallel the human counterpart.
- Author
-
Angstadt AY, Motsinger-Reif A, Thomas R, Kisseberth WC, Guillermo Couto C, Duval DL, Nielsen DM, Modiano JF, and Breen M
- Subjects
- Animals, Comparative Genomic Hybridization, Core Binding Factor Alpha 1 Subunit genetics, DNA Copy Number Variations, Dogs, Female, Gene Dosage, Genomic Instability, Humans, In Situ Hybridization, Fluorescence, Male, Membrane Proteins genetics, PTEN Phosphohydrolase genetics, Real-Time Polymerase Chain Reaction, Reproducibility of Results, Tumor Suppressor Proteins genetics, Bone Neoplasms genetics, Bone Neoplasms veterinary, Dog Diseases genetics, Osteosarcoma genetics, Osteosarcoma veterinary
- Abstract
Osteosarcoma (OS) is the most commonly diagnosed malignant bone tumor in humans and dogs, characterized in both species by extremely complex karyotypes exhibiting high frequencies of genomic imbalance. Evaluation of genomic signatures in human OS using array comparative genomic hybridization (aCGH) has assisted in uncovering genetic mechanisms that result in disease phenotype. Previous low-resolution (10-20 Mb) aCGH analysis of canine OS identified a wide range of recurrent DNA copy number aberrations, indicating extensive genomic instability. In this study, we profiled 123 canine OS tumors by 1 Mb-resolution aCGH to generate a dataset for direct comparison with current data for human OS, concluding that several high frequency aberrations in canine and human OS are orthologous. To ensure complete coverage of gene annotation, we identified the human refseq genes that map to these orthologous aberrant dog regions and found several candidate genes warranting evaluation for OS involvement. Specifically, subsequenct FISH and qRT-PCR analysis of RUNX2, TUSC3, and PTEN indicated that expression levels correlated with genomic copy number status, showcasing RUNX2 as an OS associated gene and TUSC3 as a possible tumor suppressor candidate. Together these data demonstrate the ability of genomic comparative oncology to identify genetic abberations which may be important for OS progression. Large scale screening of genomic imbalance in canine OS further validates the use of the dog as a suitable model for human cancers, supporting the idea that dysregulation discovered in canine cancers will provide an avenue for complementary study in human counterparts., (Copyright © 2011 Wiley-Liss, Inc.)
- Published
- 2011
- Full Text
- View/download PDF
28. Gene expression profile and response to maize kernels by Aspergillus flavus.
- Author
-
Reese BN, Payne GA, Nielsen DM, and Woloshuk CP
- Subjects
- 6-Phytase genetics, Aspergillus flavus growth & development, Aspergillus flavus pathogenicity, Down-Regulation, Gene Expression Profiling methods, Oligonucleotide Array Sequence Analysis methods, Reverse Transcriptase Polymerase Chain Reaction, Seeds microbiology, Sequence Deletion, Transformation, Genetic, Up-Regulation, Virulence, Zea mays growth & development, 6-Phytase metabolism, Aflatoxins biosynthesis, Aspergillus flavus enzymology, Aspergillus flavus genetics, Gene Expression Regulation, Fungal genetics, Zea mays microbiology
- Abstract
Aspergillus flavus causes an ear rot of maize, often resulting in the production of aflatoxin, a potent liver toxin and carcinogen that impacts the health of humans and animals. Many aspects of kernel infection and aflatoxin biosynthesis have been studied but the precise effects of the kernel environment on A. flavus are poorly understood. The goal of this research was to study the fungal response to the kernel environment during colonization. Gene transcription in A. flavus was analyzed by microarrays after growth on kernels of the four developmental stages: blister (R2), milk (R3), dough (R4), and dent (R5). Five days after inoculation, total RNA was isolated from kernels and hybridized to Affymetrix Gene Chip arrays containing probes representing 12,834 A. flavus genes. Statistical comparisons of the expression profile data revealed significant differences that included unique sets of upregulated genes in each kernel stage and six patterns of expression over the four stages. Among the genes expressed in colonized dent kernels were a phytase gene and six putative genes involved in zinc acquisition. Disruption of the phytase gene phy1 resulted in reduced growth on medium containing phytate as the sole source of phosphate. Furthermore, growth of the mutant (Δphy1) was 20% of the wild-type strain when wound inoculated into maize ears. In contrast, no difference was detected in the amount of aflatoxin produced relative to fungal growth, indicating that phy1 does not affect aflatoxin production. The study revealed the genome-wide effects of immature maize kernels on A. flavus and suggest that phytase has a role in pathogenesis.
- Published
- 2011
- Full Text
- View/download PDF
29. Genome-wide linkage study of atopic dermatitis in West Highland White Terriers.
- Author
-
Salzmann CA, Olivry TJ, Nielsen DM, Paps JS, Harris TL, and Olby NJ
- Subjects
- Animals, Chromosome Mapping, Dogs, Genotype, Dermatitis, Atopic genetics, Dermatitis, Atopic veterinary, Dog Diseases genetics, Genetic Linkage
- Abstract
Background: Canine atopic dermatitis (AD) is a common, heritable, chronic allergic skin condition prevalent in the West Highland White Terrier (WHWT). In canine AD, environmental allergens trigger an inflammatory response causing visible skin lesions and chronic pruritus that can lead to secondary bacterial and yeast infections. The disorder shares many of the clinical and histopathological characteristics of human AD and represents an animal model of this disorder that could be used to further elucidate genetic causes of human AD. Microsatellite markers genotyped in families of WHWTs affected with AD were used to perform a genome-wide linkage study in order to isolate chromosomal regions associated with the disorder., Results: Blood samples and health questionnaires were collected from 108 WHWTs spanning three families. A linkage simulation using these 108 dogs showed high power to detect a highly penetrant mutation. Ninety WHWTs were genotyped using markers from the Minimal Screening Set 2 (MSS-2). Two hundred and fifty six markers were informative and were used for linkage analysis. Using a LOD score of 2.7 as a significance threshold, no chromosomal regions were identified with significant linkage to AD. LOD scores greater than 1.0 were located in a 56 cM region of chromosome 7., Conclusions: The study was unable to detect any chromosomal regions significantly linked to canine AD. This could be a result of factors such as environmental modification of phenotype, incorrect assignment of phenotype, a mutation of low penetrance, or incomplete genome coverage. A genome-wide SNP association study in a larger cohort of WHWTs may prove more successful by providing higher density coverage and higher statistical power.
- Published
- 2011
- Full Text
- View/download PDF
30. Pediatric stroke: clinical characteristics, acute care utilization patterns, and mortality.
- Author
-
Statler KD, Dong L, Nielsen DM, and Bratton SL
- Subjects
- Age Factors, Child, Child, Preschool, Databases, Factual, Female, Humans, Infant, Infant, Newborn, Male, Neurosurgical Procedures statistics & numerical data, Respiration, Artificial statistics & numerical data, Thrombolytic Therapy statistics & numerical data, Critical Care statistics & numerical data, Hospitals statistics & numerical data, Stroke mortality, Stroke therapy
- Abstract
Purpose: Acute care utilization patterns are not well described but may help inform care coordination and treatment for pediatric stroke. The Kids Inpatient Database was queried to describe demographics and clinical characteristics of children with stroke, compare acute care utilization for hemorrhagic vs. ischemic stroke and Children's vs. non-Children's Hospitals, and identify factors associated with aggressive care and in-hospital mortality., Methods: Using a retrospective cohort of children hospitalized with stroke, demographics, predisposing conditions, and intensive (mechanical ventilation, advanced monitoring, and blood product administration) or aggressive (pharmacological therapy and/or invasive interventions) care were compared by stroke and hospital types. Factors associated with aggressive care or in-hospital mortality were explored using logistic regression., Results: Hemorrhagic stroke comprised 43% of stroke discharges, was more common in younger children, and carried greater mortality. Ischemic stroke was more common in older children and more frequently associated with a predisposing condition. Rates of intensive and aggressive care were low (30% and 15%), similar by stroke type, and greater at Children's Hospitals. Older age, hemorrhagic stroke, predisposing condition, and treatment at a Children's Hospital were associated with aggressive care. Hemorrhagic stroke and aggressive care were associated with in-hospital mortality., Conclusions: Acute care utilization is similar by stroke type but both intensive and aggressive care are more common at Children's Hospitals. Mortality remains relatively high after pediatric stroke. Widespread implementation of treatment guidelines improved outcomes in adult stroke. Adoption of recently published treatment recommendations for pediatric stroke may help standardize care and improve outcomes.
- Published
- 2011
- Full Text
- View/download PDF
31. An exploratory event-related potential study of multisensory integration in sensory over-responsive children.
- Author
-
Brett-Green BA, Miller LJ, Schoen SA, and Nielsen DM
- Subjects
- Acoustic Stimulation, Adolescent, Age Factors, Brain Mapping, Child, Child, Preschool, Female, Functional Laterality physiology, Humans, Male, Photic Stimulation, Brain physiopathology, Evoked Potentials, Somatosensory physiology, Somatosensory Disorders physiopathology
- Abstract
Children who are over-responsive to sensation have defensive and "fight or flight" reactions to ordinary levels of sensory stimulation in the environment. Based on clinical observations, sensory over-responsivity is hypothesized to reflect atypical neural integration of sensory input. To examine a possible underlying neural mechanism of the disorder, integration of simultaneous multisensory auditory and somatosensory stimulation was studied in twenty children with sensory over-responsivity (SOR) using event-related potentials (ERPs). Three types of sensory stimuli were presented and ERPs were recorded from thirty-two scalp electrodes while participants watched a silent cartoon: bilateral auditory clicks, right somatosensory median nerve electrical pulses, or both simultaneously. The paradigm was passive; no behavioral responses were required. To examine integration, responses to simultaneous multisensory auditory-somatosensory stimulation were compared to the sum of unisensory auditory plus unisensory somatosensory responses in four time-windows: (60-80 ms, 80-110 ms, 110-150 ms, and 180-220 ms). Specific midline and lateral electrode sites were examined over scalp regions where auditory-somatosensory integration was expected based on previous studies. Midline electrode sites (Fz, Cz, and Pz) showed significant integration during two time-windows: 60-80 ms and 180-220 ms. Significant integration was also found at contralateral electrode site (C3) for the time-window between 180 and 220 ms. At ipsilateral electrode sites (C4 and CP6), no significant integration was found during any of the time-windows (i.e. the multisensory ERP was not significantly different from the summed unisensory ERP). These results demonstrate that MSI can be reliably measured in children with SOR and provide evidence that multisensory auditory-somatosensory input is integrated during both early and later stages of sensory information processing, mainly over fronto-central scalp regions., (2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
32. Genomic hotspots for adaptation: the population genetics of Müllerian mimicry in Heliconius erato.
- Author
-
Counterman BA, Araujo-Perez F, Hines HM, Baxter SW, Morrison CM, Lindstrom DP, Papa R, Ferguson L, Joron M, Ffrench-Constant RH, Smith CP, Nielsen DM, Chen R, Jiggins CD, Reed RD, Halder G, Mallet J, and McMillan WO
- Subjects
- Animals, Chromosomes, Artificial, Bacterial genetics, Gene Expression Regulation, Genetic Loci genetics, Genetic Variation, Genotype, Hybridization, Genetic, Linkage Disequilibrium genetics, Open Reading Frames genetics, Peru, Phenotype, Physical Chromosome Mapping, Pigmentation genetics, Polymorphism, Single Nucleotide genetics, Sequence Analysis, DNA, Adaptation, Physiological genetics, Butterflies genetics, Genetics, Population, Genome genetics
- Abstract
Wing pattern evolution in Heliconius butterflies provides some of the most striking examples of adaptation by natural selection. The genes controlling pattern variation are classic examples of Mendelian loci of large effect, where allelic variation causes large and discrete phenotypic changes and is responsible for both convergent and highly divergent wing pattern evolution across the genus. We characterize nucleotide variation, genotype-by-phenotype associations, linkage disequilibrium (LD), and candidate gene expression patterns across two unlinked genomic intervals that control yellow and red wing pattern variation among mimetic forms of Heliconius erato. Despite very strong natural selection on color pattern, we see neither a strong reduction in genetic diversity nor evidence for extended LD across either patterning interval. This observation highlights the extent that recombination can erase the signature of selection in natural populations and is consistent with the hypothesis that either the adaptive radiation or the alleles controlling it are quite old. However, across both patterning intervals we identified SNPs clustered in several coding regions that were strongly associated with color pattern phenotype. Interestingly, coding regions with associated SNPs were widely separated, suggesting that color pattern alleles may be composed of multiple functional sites, conforming to previous descriptions of these loci as "supergenes." Examination of gene expression levels of genes flanking these regions in both H. erato and its co-mimic, H. melpomene, implicate a gene with high sequence similarity to a kinesin as playing a key role in modulating pattern and provides convincing evidence for parallel changes in gene regulation across co-mimetic lineages. The complex genetic architecture at these color pattern loci stands in marked contrast to the single casual mutations often identified in genetic studies of adaptation, but may be more indicative of the type of genetic changes responsible for much of the adaptive variation found in natural populations., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2010
- Full Text
- View/download PDF
33. Physiological and behavioral differences in sensory processing: a comparison of children with autism spectrum disorder and sensory modulation disorder.
- Author
-
Schoen SA, Miller LJ, Brett-Green BA, and Nielsen DM
- Abstract
A high incidence of sensory processing difficulties exists in children with Autism Spectrum Disorder (ASD) and children with Sensory Modulation Disorder (SMD). This is the first study to directly compare and contrast these clinical disorders. Sympathetic nervous system markers of arousal and reactivity were utilized in a laboratory paradigm that administered a series of sensory challenges across five sensory domains. The Short Sensory Profile, a standardized parent-report measure, provided a measure of sensory-related behaviors. Physiological arousal and sensory reactivity were lower in children with ASD whereas reactivity after each sensory stimulus was higher in SMD, particularly to the first stimulus in each sensory domain. Both clinical groups had significantly more sensory-related behaviors than typically developing children, with contrasting profiles. The ASD group had more taste/smell sensitivity and sensory under-responsivity while the SMD group had more atypical sensory seeking behavior. This study provides preliminary evidence distinguishing sympathetic nervous system functions and sensory-related behaviors in Autism Spectrum Disorder and Sensory Modulation Disorder. Differentiating the physiology and sensory symptoms in clinical groups is essential to the provision of appropriate interventions.
- Published
- 2009
- Full Text
- View/download PDF
34. Perspectives on sensory processing disorder: a call for translational research.
- Author
-
Miller LJ, Nielsen DM, Schoen SA, and Brett-Green BA
- Abstract
THIS ARTICLE EXPLORES THE CONVERGENCE OF TWO FIELDS, WHICH HAVE SIMILAR THEORETICAL ORIGINS: a clinical field originally known as sensory integration and a branch of neuroscience that conducts research in an area also called sensory integration. Clinically, the term was used to identify a pattern of dysfunction in children and adults, as well as a related theory, assessment, and treatment method for children who have atypical responses to ordinary sensory stimulation. Currently the term for the disorder is sensory processing disorder (SPD). In neuroscience, the term sensory integration refers to converging information in the brain from one or more sensory domains. A recent subspecialty in neuroscience labeled multisensory integration (MSI) refers to the neural process that occurs when sensory input from two or more different sensory modalities converge. Understanding the specific meanings of the term sensory integration intended by the clinical and neuroscience fields and the term MSI in neuroscience is critical. A translational research approach would improve exploration of crucial research questions in both the basic science and clinical science. Refinement of the conceptual model of the disorder and the related treatment approach would help prioritize which specific hypotheses should be studied in both the clinical and neuroscience fields. The issue is how we can facilitate a translational approach between researchers in the two fields. Multidisciplinary, collaborative studies would increase knowledge of brain function and could make a significant contribution to alleviating the impairments of individuals with SPD and their families.
- Published
- 2009
- Full Text
- View/download PDF
35. Mouse model of fragile X syndrome: behavioral and hormonal response to stressors.
- Author
-
Nielsen DM, Evans JJ, Derber WJ, Johnston KA, Laudenslager ML, Crnic LS, and Maclean KN
- Subjects
- Animals, Association Learning physiology, Avoidance Learning physiology, Conditioning, Psychological physiology, Corticosterone blood, Disease Models, Animal, Electroshock, Fragile X Mental Retardation Protein genetics, Freezing Reaction, Cataleptic, Male, Memory physiology, Mice, Mice, Inbred C57BL, Mice, Knockout, Restraint, Physical, Swimming, Taste, Fragile X Syndrome physiopathology, Fragile X Syndrome psychology, Stress, Psychological physiopathology
- Abstract
Fragile X syndrome, a form of mental retardation caused by inadequate levels of fragile X mental retardation protein (FMRP), is characterized by extreme sensitivity to sensory stimuli and increased behavioral and hormonal reactivity to stressors. Fmr1 knockout mice lack FMRP and exhibit abnormal responses to auditory stimuli. This study sought to determine whether Fmr1 knockout mice on an F1 hybrid background are normal in their response to footshock. Knockout mice were also examined for signs of hyperexcitation across an extended trial range, and serum corticosterone levels were evaluated in response to various stressors. The ability to acquire conditioned taste aversion was also assessed. Knockout mice exhibited no impairment in associative aversive learning or memory, since they successfully expressed conditioned taste aversion. Footshock-sensitivity, freezing behavior, and corticosterone response to various stressors did not differ between knockout and wild-type mice. However, knockout mice exhibited significantly increased responses during the extended test. The knockout mice's increased responsiveness to footshock in the extended test may be an indication of increased vulnerability to stress or enhanced emotional reactivity., (Copyright (c) 2009 APA, all rights reserved.)
- Published
- 2009
- Full Text
- View/download PDF
36. The effect of temperature on Natural Antisense Transcript (NAT) expression in Aspergillus flavus.
- Author
-
Smith CA, Robertson D, Yates B, Nielsen DM, Brown D, Dean RA, and Payne GA
- Subjects
- Aspergillus flavus metabolism, Expressed Sequence Tags, Fungal Proteins genetics, Fungal Proteins metabolism, Genome, Fungal, RNA Precursors metabolism, Transcription, Genetic genetics, Aspergillus flavus genetics, Gene Expression Regulation, Fungal, RNA, Antisense metabolism, Temperature
- Abstract
Naturally occurring Antisense Transcripts (NATs) compose an emerging group of regulatory RNAs. These regulatory elements appear in all organisms examined, but little is known about global expression of NATs in fungi. Analysis of currently available EST sequences suggests that 352 cis NATs are present in Aspergillus flavus. An Affymetrix GeneChip microarray containing probes for these cis NATs, as well as all predicted genes in A. flavus, allowed a whole genome expression analysis of these elements in response to two ecologically important temperatures for the fungus. RNA expression analysis showed that 32 NATs and 2,709 genes were differentially expressed between 37 degrees C, the optimum temperature for growth, and 28 degrees C, the conducive temperature for the biosynthesis of aflatoxin (AF) and many other secondary metabolites. These NATs correspond to sense genes with diverse functions including transcription initiation, carbohydrate processing and binding, temperature sensitive morphogenesis, and secondary metabolism. This is the first report of a whole genome transcriptional analysis of NAT expression in a fungus.
- Published
- 2008
- Full Text
- View/download PDF
37. Does strong linkage disequilibrium guarantee redundant association results?
- Author
-
Nielsen DM, Suchindran S, and Smith CP
- Subjects
- Computer Simulation, Gene Frequency, Genetic Markers, Haplotypes, Humans, Phenotype, Polymorphism, Single Nucleotide, Quantitative Trait, Heritable, Genome, Human, Linkage Disequilibrium, Models, Genetic, Models, Statistical
- Abstract
A substantial amount of effort has been expended recently towards the identification and evaluation of tag single nucleotide polymorphisms; markers that, due to linkage disequilibrium (LD) patterns in the genome, are able to act as "proxies" for other polymorphic sites. As such, these tag markers are assumed to capture, on their own, a large proportion of the genetic variation contributed by a much greater number of polymorphic sites. One important consequence of this is the potential ability to reduce the cost of genotyping in an association study without a corresponding loss of power. This application carries an implicit assumption that strong LD between markers implies high correlation between the accompanying association test results, so that once a tag marker is evaluated for association, its outcome will be representative of all the other markers for which it serves as proxy. We examined this assumption directly. We find that in the null hypothesis situation, where there is no association between the markers and the phenotype, the relationship between LD and the correlation between association test outcomes is clear, though it is not always ideal. In the alternative case, when genetic association does exist in the region, the relationship becomes much more complex. Here, reasonably high LD between markers does not necessarily imply that the association test result of one marker is a direct substitute for that of the other. In these cases, eliminating one of these markers from the set to be genotyped in an association study will lead to a reduction in overall power., ((c) 2008 Wiley-Liss, Inc.)
- Published
- 2008
- Full Text
- View/download PDF
38. Elucidation of veA-dependent genes associated with aflatoxin and sclerotial production in Aspergillus flavus by functional genomics.
- Author
-
Cary JW, OBrian GR, Nielsen DM, Nierman W, Harris-Coward P, Yu J, Bhatnagar D, Cleveland TE, Payne GA, and Calvo AM
- Subjects
- Aspergillus flavus genetics, Aspergillus flavus metabolism, Fungal Proteins genetics, Gene Expression Regulation, Fungal, Gene Library, Genomics, Aflatoxins biosynthesis, Anthraquinones metabolism, Aspergillus flavus growth & development, Fungal Proteins metabolism, Gene Expression Profiling, Oligonucleotide Array Sequence Analysis methods
- Abstract
The aflatoxin-producing fungi, Aspergillus flavus and A. parasiticus, form structures called sclerotia that allow for survival under adverse conditions. Deletion of the veA gene in A. flavus and A. parasiticus blocks production of aflatoxin as well as sclerotial formation. We used microarray technology to identify genes differentially expressed in wild-type veA and veA mutant strains that could be involved in aflatoxin production and sclerotial development in A. flavus. The DNA microarray analysis revealed 684 genes whose expression changed significantly over time; 136 of these were differentially expressed between the two strains including 27 genes that demonstrated a significant difference in expression both between strains and over time. A group of 115 genes showed greater expression in the wild-type than in the veA mutant strain. We identified a subgroup of veA-dependent genes that exhibited time-dependent expression profiles similar to those of known aflatoxin biosynthetic genes or that were candidates for involvement in sclerotial production in the wild type.
- Published
- 2007
- Full Text
- View/download PDF
39. Comprehensive transcriptome profiling in tomato reveals a role for glycosyltransferase in Mi-mediated nematode resistance.
- Author
-
Schaff JE, Nielsen DM, Smith CP, Scholl EH, and Bird DM
- Subjects
- Animals, Feeding Behavior physiology, Gene Expression, Gene Expression Profiling, Gene Silencing, Genomics, Host-Parasite Interactions physiology, Solanum lycopersicum genetics, Solanum lycopersicum parasitology, Oligonucleotide Array Sequence Analysis, Plant Roots metabolism, Plant Roots parasitology, Reproduction physiology, Gene Expression Regulation, Plant, Glycosyltransferases metabolism, Solanum lycopersicum enzymology, Plant Roots enzymology, Tylenchoidea physiology
- Abstract
Root-knot nematode (RKN; Meloidogyne spp.) is a major crop pathogen worldwide. Effective resistance exists for a few plant species, including that conditioned by Mi in tomato (Solanum lycopersicum). We interrogated the root transcriptome of the resistant (Mi+) and susceptible (Mi-) cultivars 'Motelle' and 'Moneymaker,' respectively, during a time-course infection by the Mi-susceptible RKN species Meloidogyne incognita and the Mi-resistant species Meloidogyne hapla. In the absence of RKN infection, only a single significantly regulated gene, encoding a glycosyltransferase, was detected. However, RKN infection influenced the expression of broad suites of genes; more than half of the probes on the array identified differential gene regulation between infected and uninfected root tissue at some stage of RKN infection. We discovered 217 genes regulated during the time of RKN infection corresponding to establishment of feeding sites, and 58 genes that exhibited differential regulation in resistant roots compared to uninfected roots, including the glycosyltransferase. Using virus-induced gene silencing to silence the expression of this gene restored susceptibility to M. incognita in 'Motelle,' indicating that this gene is necessary for resistance to RKN. Collectively, our data provide a picture of global gene expression changes in roots during compatible and incompatible associations with RKN, and point to candidates for further investigation.
- Published
- 2007
- Full Text
- View/download PDF
40. Pharmacotherapy of dual substance abuse and dependence.
- Author
-
Kenna GA, Nielsen DM, Mello P, Schiesl A, and Swift RM
- Subjects
- Alcoholism drug therapy, Animals, Benzodiazepines, Cocaine-Related Disorders drug therapy, Humans, Opioid-Related Disorders drug therapy, Substance-Related Disorders physiopathology, Tobacco Use Disorder drug therapy, Substance-Related Disorders drug therapy
- Abstract
The US FDA has approved a limited number of treatments for alcohol, nicotine and opioid dependence; however, no treatments for other abused drugs such as marijuana, cocaine or methamphetamine are approved. This review focuses on research into drug pharmacotherapies, particularly single-drug therapies, for substance abuse and dependence contributing to the most important dual substance use disorders (SUDs). Given the implications of poly-substance abuse, it is essential that clinicians and researchers be aware of potential pharmacotherapies for the treatment of dual SUDs.A substantial number of patients abuse more than one drug concurrently, complicating the treatment of SUD and leaving clinicians with few FDA-approved drug options for their patients. In this era of evidence-based medicine, such patients are typically treated with therapeutically proven medications, but in ways that are outside the scope of a drug's original indication by the FDA. Such 'off-label' prescribing has become an important therapeutic strategy for practitioners seeking treatments for other diseases in subpopulations such as paediatrics and gerontology or for medical conditions such as oncology or mental illness. Similarly, the information that most clinicians use to make their decisions for treating patients abusing multiple drugs stems from trials treating a single SUD, anecdotal experiences from their own practice or that of their colleagues, or single-case studies reported in the literature. The existing evidence suggests there are few treatments for SUDs that confer significant reductions in substance use across a broad patient population. Moreover, even fewer clinical efficacy trials have been conducted that provide evidence of therapeutic benefit for these drugs. Recognising the difficulty in making the proper drug choice for facilitating maximum treatment success, this review highlights the single drugs or drug combinations that show some potential for treating dual SUDs. This review finds strongest support for the use of disulfiram for treatment of alcohol and cocaine dependence (with or without concomitant methadone maintenance), baclofen for alcohol and cocaine dependence (but not opioid-dependent cocaine users), tiagabine for cocaine dependence in methadone-maintained patients, and topiramate for alcohol, nicotine and cocaine dependence. While ondansetron and olanzapine show some efficacy in treating alcohol and cocaine dependence, more research is needed to better delineate the subpopulation in which these drugs may provide their maximum effect.
- Published
- 2007
- Full Text
- View/download PDF
41. A unified mixed-model method for association mapping that accounts for multiple levels of relatedness.
- Author
-
Yu J, Pressoir G, Briggs WH, Vroh Bi I, Yamasaki M, Doebley JF, McMullen MD, Gaut BS, Nielsen DM, Holland JB, Kresovich S, and Buckler ES
- Subjects
- Gene Expression, Genetic Variation, Humans, Phenotype, Quantitative Trait, Heritable, Research Design, Genetic Techniques, Heredity genetics, Models, Genetic, Zea mays genetics
- Abstract
As population structure can result in spurious associations, it has constrained the use of association studies in human and plant genetics. Association mapping, however, holds great promise if true signals of functional association can be separated from the vast number of false signals generated by population structure. We have developed a unified mixed-model approach to account for multiple levels of relatedness simultaneously as detected by random genetic markers. We applied this new approach to two samples: a family-based sample of 14 human families, for quantitative gene expression dissection, and a sample of 277 diverse maize inbred lines with complex familial relationships and population structure, for quantitative trait dissection. Our method demonstrates improved control of both type I and type II error rates over other methods. As this new method crosses the boundary between family-based and structured association samples, it provides a powerful complement to currently available methods for association mapping.
- Published
- 2006
- Full Text
- View/download PDF
42. Corticotropin-releasing factor type-1 receptor antagonists: the next class of antidepressants?
- Author
-
Nielsen DM
- Subjects
- Animals, Corticotropin-Releasing Hormone physiology, Depressive Disorder drug therapy, Depressive Disorder genetics, Depressive Disorder psychology, Helplessness, Learned, Humans, Mice, Olfactory Bulb physiology, Pyrimidines pharmacology, Rats, Receptors, Corticotropin-Releasing Hormone genetics, Receptors, Corticotropin-Releasing Hormone physiology, Stress, Psychological physiopathology, Swimming psychology, Antidepressive Agents pharmacology, Depressive Disorder physiopathology, Receptors, Corticotropin-Releasing Hormone antagonists & inhibitors
- Abstract
Corticotropin-releasing factor (CRF) is a neuropeptide that plays a primary role in the neuroendocrine, autonomic, and behavioral responses to stressors. Numerous reports suggest that alterations in CRF function contribute to the pathogenesis of depression. Recently, selective nonpeptide CRF type 1 (CRF1) receptor antagonists have been discovered and several of these CRF1 receptor antagonists have demonstrated antidepressant-like efficacy in animals. The CRF1 receptor antagonists appear to be unique, as they exhibit antidepressant-like activity principally in animal models that are hyperresponsive to stress or under experimental conditions that alter endogenous stress-hormone activity. A nonpeptide CRF1 receptor antagonist has also been shown to reduce symptoms of major depression in an open-label clinical trial. Accumulating evidence supports a role for nonpeptide CRF1 receptor antagonists among the future pharmacotherapies for the treatment of depression.
- Published
- 2006
- Full Text
- View/download PDF
43. Measures of human population structure show heterogeneity among genomic regions.
- Author
-
Weir BS, Cardon LR, Anderson AD, Nielsen DM, and Hill WG
- Subjects
- Genomics methods, Haplotypes genetics, Humans, Linkage Disequilibrium genetics, Polymorphism, Single Nucleotide genetics, United States, Chromosomes, Human genetics, Ethnicity genetics, Genetic Heterogeneity, Genetics, Population, Genome, Human genetics
- Abstract
Estimates of genetic population structure (F(ST)) were constructed from all autosomes in two large SNP data sets. The Perlegen data set contains genotypes on approximately 1 million SNPs segregating in all three samples of Americans of African, Asian, and European descent; and the Phase I HapMap data set contains genotypes on approximately 0.6 million SNPs segregating in all four samples from specific Caucasian, Chinese, Japanese, and Yoruba populations. Substantial heterogeneity of F(ST) values was found between segments within chromosomes, although there was similarity between the two data sets. There was also substantial heterogeneity among population-specific F(ST) values, with the relative sizes of these values often changing along each chromosome. Population-structure estimates are often used as indicators of natural selection, but the analyses presented here show that individual-marker estimates are too variable to be useful. There is inherent variation in these statistics because of variation in genealogy even among neutral loci, and values at pairs of loci are correlated to an extent that reflects the linkage disequilibrium between them. Furthermore, it may be that the best indications of selection will come from population-specific F(ST) values rather than the usually reported population-average values.
- Published
- 2005
- Full Text
- View/download PDF
44. Arthroscopic visualization of the posterior horn of the medial meniscus.
- Author
-
Nielsen DM and Twyman R
- Subjects
- Humans, Intraoperative Complications prevention & control, Medial Collateral Ligament, Knee injuries, Motion, Rupture prevention & control, Stress, Mechanical, Arthroscopy methods, Menisci, Tibial pathology
- Abstract
We present a method of visualizing the posterior horn of the medial meniscus through the anterolateral portal that has not been previously described in the literature. It allows easy visualization and instrumentation of the posterior horn, an area that commonly has pathology that can be difficult to identify and treat. The technique involves allowing the knee to flex to 60 degrees to 90 degrees over the side of the bed and applying a varus force to the tibia, opening up the posteromedial part of the joint. It does not require any valgus force and therefore minimizes the risk of injury to the medial collateral ligament.
- Published
- 2005
- Full Text
- View/download PDF
45. Short-listing for orthopaedic specialist registrar posts--what is important?
- Author
-
Nielsen DM and Ricketts DM
- Subjects
- Career Mobility, Clinical Competence, England, Humans, Job Application, Time Factors, Education, Medical, Graduate organization & administration, Medical Staff, Hospital education, Orthopedics education, Personnel Selection methods
- Abstract
Introduction: Competition for specialist registrar (SpR) posts in orthopaedics is high. The aim of the current study was to provide evidence-based advice for applicants applying for SpR posts in orthopaedics., Methods: The short-listing forms of 273 applicants for orthopaedic SpR posts in South Thames (West) were reviewed. The experience of short-listed candidates was compared with those that were not., Results: We have shown a high chance of being short-listed between 5 and 6 years after qualification with a sharp fall off either side of this. It is clear that a wide range of appropriate experience is more important than high volume and low quality experience in orthopaedics alone., Conclusion: Candidates who plan ahead and gain a broad experience have a better chance of progressing in an orthopaedic career. Good, early career advice is essential to achieve this.
- Published
- 2005
- Full Text
- View/download PDF
46. Where to split plaster casts.
- Author
-
Nielsen DM and Ricketts DM
- Subjects
- Humans, Manikins, Radius Fractures complications, Casts, Surgical, Compartment Syndromes prevention & control, Radius Fractures therapy
- Abstract
Plaster casts are often split to accommodate swelling following injury. This is not influenced by the axis of the split. The aim of this study was to compare the mechanical properties of plasters split along different axes. Full plasters were applied to mannequin forearms, and then split along dorsal, volar, radial or ulnar sides. Following this the plasters were loaded in a dorsal direction. We found that of all the axes tested, the dorsal split was the best for maintaining fracture reduction (p = 0.001).
- Published
- 2005
- Full Text
- View/download PDF
47. Satisfaction levels in orthopaedic out-patients.
- Author
-
Nielsen DM, Gill K, and Ricketts DM
- Subjects
- Communication, England, Female, Humans, Information Services statistics & numerical data, Male, Orthopedics organization & administration, Outpatient Clinics, Hospital organization & administration, Outpatient Clinics, Hospital standards, Physician-Patient Relations, Surveys and Questionnaires, Orthopedics standards, Outpatients psychology, Patient Satisfaction
- Abstract
Introduction: It is important that patients are satisfied with an out-patient consultation. This ensures compliance with treatment and attendance for follow-up. The aim of this study was to identify factors regarding out-patient consultation associated with patient satisfaction., Methods: A two-part questionnaire identifying expectations of, and subsequent satisfaction with, a new out-patient consultation was completed by 106 out-patients., Results: There was no correlation between not seeing the clinician anticipated and reduced satisfaction (P = 0.17). Using more information sources was associated with less satisfaction (P = 0.02). Patients were less satisfied if their expectations of either treatment or outcome were changed., Conclusions: Meeting patients' expectations is an essential part of effective communication. The use of specialist physiotherapists and general practitioners with a special interest is an effective way of seeing more new patients.
- Published
- 2005
- Full Text
- View/download PDF
48. Association of genetic polymorphisms with risk of renal injury after coronary bypass graft surgery.
- Author
-
Stafford-Smith M, Podgoreanu M, Swaminathan M, Phillips-Bute B, Mathew JP, Hauser EH, Winn MP, Milano C, Nielsen DM, Smith M, Morris R, Newman MF, and Schwinn DA
- Subjects
- Acute Kidney Injury blood, Acute Kidney Injury ethnology, Acute Kidney Injury genetics, Black or African American genetics, Aged, Alleles, Angiotensins genetics, Apolipoproteins E genetics, Cardiovascular Diseases epidemiology, Cardiovascular Diseases surgery, Creatinine blood, Cytokines genetics, DNA Mutational Analysis, Female, Follow-Up Studies, Genetic Predisposition to Disease, Humans, Male, Middle Aged, Nitric Oxide Synthase genetics, Nitric Oxide Synthase Type III, North Carolina epidemiology, Prospective Studies, Pulmonary Disease, Chronic Obstructive epidemiology, Receptor, Angiotensin, Type 1 genetics, Risk, White People genetics, Acute Kidney Injury epidemiology, Coronary Artery Bypass, Polymorphism, Genetic, Postoperative Complications epidemiology
- Abstract
Background: Post-cardiac surgery renal dysfunction is a common, serious, multifactorial disorder, with interpatient variability predicted poorly by preoperative clinical, procedural, and biological markers. Therefore, we tested the hypothesis that selected gene variants are associated with acute renal injury, reflected by a serum creatinine level increase after cardiac surgery., Methods: One thousand six hundred seventy-one patients undergoing aortocoronary surgery were studied. Clinical covariates were recorded. DNA was isolated from preoperative blood; mass spectrometry was used for genotype analysis. A model was developed relating clinical and genetic factors to postoperative acute renal injury., Results: A race effect was found; therefore, Caucasians and African Americans were analyzed separately. Overall, clinical factors alone account poorly for postoperative renal injury, although more so in African Americans than Caucasians. When 12 candidate polymorphisms were assessed, 2 alleles (interleukin 6 -572C and angiotensinogen 842C) showed a strong association with renal injury in Caucasians (P < 0.0001; >50% decrease in renal filtration when they present together). Using less stringent criteria for significance (0.01 > P > 0.001), 4 additional polymorphisms are identified (apolipoproteinE 448C [4], angiotensin receptor1 1166C, and endothelial nitric oxide synthase [eNOS] 894T in Caucasians; eNOS 894T and angiotensin-converting enzyme deletion and insertion in African Americans). Adding genetic to clinical factors resulted in the best model, with overall ability to explain renal injury increasing approximately 4-fold in Caucasians and doubling in African Americans (P < 0.0005)., Conclusion: In this study, we identify genetic polymorphisms that collectively provide 2- to 4-fold improvement over preoperative clinical factors alone in explaining post-cardiac surgery renal dysfunction. From a mechanistic perspective, most identified genetic variants are associated with increased renal inflammatory and/or vasoconstrictor responses.
- Published
- 2005
- Full Text
- View/download PDF
49. Keeping plaster casts dry: what works?
- Author
-
Nielsen DM, Ripley LG, and Ricketts DM
- Subjects
- Activities of Daily Living, Equipment Design, Equipment Failure, Fractures, Bone rehabilitation, Fractures, Bone surgery, Humans, Casts, Surgical, Protective Devices, Water
- Abstract
Plaster casts are commonly used in the management of fractures. The mechanical properties of plasters are adversely affected by water. There are a number of commercial products available to allow patients to continue to shower and swim by protecting the plaster. The aim of this study was to compare these products with a plastic bag and elastic band. Each protector was tested in a shower, immersed in a swimming pool and worn while swimming. The volume of water intrusion was measured. There was no significant difference between a plastic bag and the commercially available products. We do not recommend the use of commercially available plaster protectors for showering or swimming: a plastic bag and elastic band is a cheaper and more convenient device.
- Published
- 2005
- Full Text
- View/download PDF
50. Response to paper by SP Smith Olecranon fractures--a reliable technique for accurate positioning of the tension band wire.
- Author
-
Nielsen DM and Twyman R
- Subjects
- Humans, Bone Wires, Fracture Fixation instrumentation, Ulna Fractures surgery
- Published
- 2004
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.