11 research outputs found
Blood flow in chronic stroke lesions: an improved model of brain-behavior relationships
With more stroke patients living into the chronic stage, there is a need to address the chronic behavioral deficits that come with this longer lifespan. In order to create improved brain-behavioral maps, we identify the relationship between tissue integrity and blood flow, and then use both as inputs to better describe the variability of behavioral deficits.M.S
ASL MRI informs blood flow to chronic stroke lesions in patients with aphasia
Introduction: Response to post-stroke aphasia language rehabilitation is difficult to anticipate, mainly because few predictors can help identify optimal, individualized treatment options. Imaging techniques, such as Voxel-based Lesion Symptom Mapping have been useful in linking specific brain areas to language behavior; however, further development is required to optimize the use of structural and physiological information in guiding individualized treatment for persons with aphasia (PWA). In this study, we will determine if cerebral blood flow (CBF) mapped in patients with chronic strokes can be further used to understand stroke-related factors and behavior.Methods: We collected perfusion MRI data using pseudo-Continuous Arterial Spin Labeling (pCASL) using a single post-labeling delay of 2,200Â ms in 14 chronic PWA, along with high-resolution structural MRI to compute maps of tissue damage using Tissue Integrity Gradation via T2w T1w Ratio (TIGR). To quantify the CBF in chronic stroke lesions, we tested at what point spatial smoothing should be applied in the ASL analysis pipeline. We then related CBF to tissue damage, time since stroke, age, sex, and their respective cross-terms to further understand the variability in lesion CBF. Finally, we assessed the feasibility of computing multivariate brain-behavior maps using CBF and compared them to brain-behavior maps extracted with TIGR MRI.Results: We found that the CBF in chronic stroke lesions is significantly reduced compared to its homologue grey and white matter regions. However, a reliable CBF signal (although smaller than expected) was detected to reveal a negative relationship between CBF and increasing tissue damage. Further, the relationship between the lesion CBF and age, sex, time since stroke, and tissue damage and cross-terms suggested an aging-by-disease interaction. This relationship was strongest when smoothing was applied in the template space. Finally, we show that whole-brain CBF relates to domain-general visuospatial functioning in PWA. The CBF-based brain-behavior maps provide unique and complementary information to structural (lesion-based) brain-behavior maps.Discussion: Therefore, CBF can be detected in chronic stroke lesions using a standard pCASL MRI acquisition and is informative at the whole-brain level in identifying stroke rehabilitation targets in PWAs due to its relationship with demographic factors, stroke-related factors, and behavior
A study of sertraline in dialysis (ASSertID) : a protocol for a pilot randomised controlled trial of drug treatment for depression in patients undergoing haemodialysis
© 2015 Friedli et al. Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedBACKGROUND: The prevalence of depression in people receiving haemodialysis is high with estimates varying between 20 and 40 %. There is little research on the effectiveness of antidepressants in dialysis patients with the few clinical trials suffering significant methodological issues. We plan to carry out a study to evaluate the feasibility of conducting a randomised controlled trial in patients on haemodialysis who have diagnosed Major Depressive Disorder.METHODS/DESIGN: The study has two phases, a screening phase and the randomised controlled trial. Patients will be screened initially with the Beck Depression Inventory to estimate the number of patients who score 16 or above. These patients will be invited to an interview with a psychiatrist who will invite those with a diagnosis of Major Depressive Disorder to take part in the trial. Consenting patients will be randomised to either Sertraline or placebo. Patients will be followed-up for 6 months. Demographic and clinical data will be collected at screening interview, baseline interview and 2 weeks, and every month (up to 6 months) after baseline. The primary outcome is to evaluate the feasibility of conducting a randomised, double blind, placebo pilot trial in haemodialysis patients with depression. Secondary outcomes include estimation of the variability in the outcome measures for the treatment and placebo arms, which will allow for a future adequately powered definitive trial. Analysis will primarily be descriptive, including the number of patients eligible for the trial, drug exposure of Sertraline in haemodialysis patients and the patient experience of participating in this trial.DISCUSSION: There is an urgent need for this research in the dialysis population because of the dearth of good quality and adequately powered studies. Research with renal patients is particularly difficult as they often have complex medical needs. This research will therefore not only assess the outcome of anti-depressants in haemodialysis patients with depression but also the process of running a randomised controlled trial in this population. Hence, the outputs of this feasibility study will be used to inform the design and methodology of a definitive study, adequately powered to determine the efficacy of anti-depressants in patient on haemodialysis with depression.TRIAL REGISTRATION: ISRCTN registry ISRCTN06146268 and EudraCT reference: 2012-000547-27.Peer reviewedFinal Published versio
Gender-related mental health differences between refugees and non-refugee immigrants - a cross-sectional register-based study
<p>Abstract</p> <p>Background</p> <p>Being an immigrant in a high-income country is a risk factor for severe mental ill health. Studies on mental ill health among immigrants have found significant differences in mental health outcome between immigrants from high income countries and low-income countries. Being an asylum seeker or a refugee is also associated with mental ill health. This study aimed to assess if there is a difference in mental ill health problems between male and female refugee and non-refugee immigrants from six low-income countries in Sweden.</p> <p>Methods</p> <p>A cross-sectional, population-based study design was used comparing refugees with non-refugees. The study size was determined by the number of persons in Sweden fulfilling the inclusion criteria at the time of the study during 2006. Outcome: Mental ill health, as measured with the proxy variable psychotropic drugs purchased. Refugee/Non-refugee: Sweden grants asylum to refugees according to the Geneva Convention and those with a well-grounded fear of death penalty, torture or who need protection due to an internal or external armed conflict or an environmental disaster. The non-refugees were all family members of those granted asylum in Sweden. Covariates: Gender and origin. Potential confounders: Age, marital status, education and duration of stay in Sweden. Background variables were analysed using chi square tests. The association between outcome, exposure and possible confounders was analysed using logistic regression analyses. Multiple logistic regression analysis was used to adjust for potential confounders.</p> <p>Results</p> <p>The study population comprised 43,168 refugees and non-refugees, of whom 20,940 (48.5%) were women and 24,403 (56.5%) were refugees. Gender, age, origin, marital status and education were all associated with the outcome. For female, but not male, refugees there was a significantly higher likelihood of purchasing psychotropic drugs than non-refugees (OR = 1.27, 95% CI = 1.15 - 1.40).</p> <p>Conclusions</p> <p>Female refugees from low-income countries seem to be a risk group among immigrant women from low-income countries, whereas male refugees had the same risk patterns as non-refugee immigrants from low-income countries. This underlines the need for training of clinicians in order to focus on pre-migration stress and the asylum process, among female newcomers.</p
Three Minute Thesis (3MT) 2021
Presented online April 9, 2021, 3:00 p.m.-4:40 p.m.Since 2015, Techâs version of this international competition, which started at The University of Queensland, Australia, has provided graduate students with an opportunity to hone their professional skills and win prize money to help further their research efforts. The competition challenges students to explain their research in three minutes in a way that anyone can understand.Hosts (Members of Georgia Institute of Technology): Jeff Garbers, Enterprise Innovation Institute, Venture Lab; Bonnie H. Ferri, Vice Provost for Graduate Education and Faculty Development; James Black, Assistant Director of Strategic Initiatives and Grad Life, Office of Graduate Studies; and Leslie Sharp, Dean of the Library.Judges: Ashley Bush, Director, Communications and Employee Engagement, Southwire Company, LLC; Duffie Dixon, Owner, Duffie Dixon Media; Charles Edwards, Coaching Practice Lead, Jackson Spalding; Dene Sheheane,
President, Georgia Tech Alumni Association; and Brian Yablunosky, Senior Manager, Digital Channels, Global Communications VMWare.Participant and PhD Division Winner (1000 Travel Grant) AND Peopleâs Choice Award (500 Travel Grant): Megan McSweeney, Chemical and Biomolecular Engineering; Advisor: Mark Styczynski; TITLE: âAptaTrigger: A Novel Biosensor Platform for Point-of-Care Diagnosticsâ.Participant: Mohammad S. E Sendi, Biomedical Engineering; Advisors: Babak Mahmoudi & Robert E. Gross; TITLE: âPersonalized Deep Brain Stimulation: A Window of Hope for Depressionâ.Participant: Yifeng Shi, Chemical and Biomolecular Engineering; Advisor: Younan Xia; TITLE: âShape-Controlled Pd Nanocrystals: Surface Science and Catalytic Applicationsâ.Participant: Andrew Tricker, Chemical Engineering; Advisor: Carsten Sievers; TITLE: âCracking the Case of Sustainable Fertilizzers: Ambient Ammonia Synthesis via Mechanocatalysisâ.Participant: Jelly Vanderwoude, Biological Sciences; Advisor: Stephen Diggle; TITLE: âDiscovering Novel Genetic Markers of Antibiotic Resistant in Cystic Fibrosis Lung Infection of Pseudomonas Aeruginosaâ.Participant: Young Hee Yoon, Chemical and Biomolecular Engineering; Advisor: Ryan P. Lively; TITLE: âUnderstanding and Controlling Co-Transport of Water and Organic Solvents in Microporous Carbon Molecular Sieve (CMS) Membranesâ.Participant and PhD Division, Runner Up (1500 Travel Grant): Muhammad Saad Zia, Electrical and Computer Engineering; Advisors: Mary Ann Weitnauer & Douglas M. Blough; TITLE: âMitigating Beam Alignment Errors in Millimeter-Wave Communications to Go Beyond 5Gâ.Participant and Masterâs Division: Winner ($1000 Travel Grant): Clara Glassman, Medical Physics; Advisors: Lisa Krishnamurthy & C. K. Wang; TITLE: âCreating the Google Maps of Brain-Behavior Relationships: A New Look at Post Stroke MRIsâ.Runtime: 54:33 minutesFor the first time, the final round of Georgia Techâs annual Three Minute Thesis (3MT) Competition will be held virtually. Ten Ph.D. students and one masterâs student (who was awarded first place in the masterâs category and will be competing for the Peopleâs Choice Award) made the cut to participate in the finals
Viraemia suppressed in HIV-1-infected humans by broadly neutralizing antibody 3BNC117
HIV-1 immunotherapy with a combination of first generation monoclonal antibodies was largely ineffective in pre-clinical and clinical settings and was therefore abandoned(1-3). However, recently developed single-cell-based antibody cloning methods have uncovered a new generation of far more potent broadly neutralizing antibodies to HIV-1 (refs 4, 5). These antibodies can prevent infection and suppress viraemia in humanized mice and nonhuman primates, but their potential for human HIV-1 immunotherapy has not been evaluated(6-10). Here we report the results of a first-in-man dose escalation phase 1 clinical trial of 3BNC117, a potent human CD4 binding site antibody(11), in uninfected and HIV-1-infected individuals. 3BNC117 infusion was well tolerated and demonstrated favourable pharmacokinetics. A single 30mg kg(-1) infusion of 3BNC117 reduced the viral load in HIV-1-infected individuals by 0.8-2.5 log(10) and viraemia remained significantly reduced for 28 days. Emergence of resistant viral strains was variable, with some individuals remaining sensitive to 3BNC117 for a period of 28 days. We conclude that, as a single agent, 3BNC117 is safe and effective in reducing HIV-1 viraemia, and that immunotherapy should be explored as a new modality for HIV-1 prevention, therapy and cure
Temperature and pH define the realised niche space of arbuscular mycorrhizal fungi
The arbuscular mycorrhizal (AM) fungi are a globally distributed group of soil organisms that play critical roles in ecosystem function. However, the ecological niches of individual AM fungal taxa are poorly understood. We collected > 300 soil samples from natural ecosystems worldwide and modelled the realised niches of AM fungal virtual taxa (VT; approximately species-level phylogroups). We found that environmental and spatial variables jointly explained VT distribution worldwide, with temperature and pH being the most important abiotic drivers, and spatial effects generally occurring at local to regional scales. While dispersal limitation could explain some variation in VT distribution, VT relative abundance was almost exclusively driven by environmental variables. Several environmental and spatial effects on VT distribution and relative abundance were correlated with phylogeny, indicating that closely related VT exhibit similar niche optima and widths. Major clades within the Glomeraceae exhibited distinct niche optima, Acaulosporaceae generally had niche optima in low pH and low temperature conditions, and Gigasporaceae generally had niche optima in high precipitation conditions. Identification of the realised niche space occupied by individual and phylogenetic groups of soil microbial taxa provides a basis for building detailed hypotheses about how soil communities respond to gradients and manipulation in ecosystems worldwide