2,725 results on '"Samuel L"'
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2. Clinical audit of cases and outcomes of patients admitted to the intensive care unit at Kamuzu Central Hospital, Lilongwe, Malawi
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Akim Nelson Bwanali, Leonard Munthali, Upile Napolo, Adriano Focus Lubanga, Rodwell Gundo, and Samuel L. Mpinganjira
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Critical care ,Intensive care unit (ICU) ,Malawi ,Medicine ,Science - Abstract
Abstract In 2016, a new, improved and modern intensive care unit was constructed at Kamuzu Central Hospital in Lilongwe, Malawi. Having been operational for about 4 years, there has not been a systematic audit to gauge its performance. Therefore, this quantitative retrospective cohort study aimed at investigating the performance of the intensive care unit at Kamuzu Central Hospital in Lilongwe, Malawi. We analysed the patterns of admission through 250 clinical cases and their respective outcomes spanning from 1st January 2019 to 31st December 2019 using STATA. Descriptive and inferential statistics were computed. We also had a follow-up discussion with the Head of the unit to better understand the unit’s functioning. Out of the 250 admissions, we evaluated 249 case files. About 30.8% of all patients were referred from the main operating theatre, and 20.7% from the casualty (emergency medicine). Head injury (26.7%) and peritonitis (15.7%) were the commonest causes of admission. The overall mortality was 52.2% with more females (57.5%) dying than males (47.9%). Head injury and peritonitis had the highest contribution to the mortality accounting for 25.3% and 16.9% of all deaths respectively. In conclusion, despite the new unit registering an improved performance compared to the old unit’s 2012 mortality of 60.9%, the current mortality rate of 52.2% generally reflects a suboptimal performance. The intensive care unit is still grappling with a number of challenges that need immediate attention including few working beds, shortage of critical care specialists and nursing staff and lack of standard admission criteria.
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- 2024
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3. Engaging communities to inform the development of a diverse cohort of cancer survivors: formative research for the eat move sleep study (EMOVES)
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Ghilamichael Andemeskel, Nynikka R. Palmer, Rena Pasick, Erin L. Van Blarigan, Stacey A. Kenfield, Rebecca E. Graff, Michael Shaw, Wil Yu, Mayte Sanchez, Roberto Hernandez, Samuel L. Washington, Salma Shariff-Marco, Kim F. Rhoads, and June M. Chan
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Medicine ,Medicine (General) ,R5-920 - Abstract
Abstract Background There are more than 18 million cancer survivors in the United States. Yet, survivors of color remain under-represented in cancer survivorship research (Saltzman et al. in Contemp Clin Trials Commun 29:100986, 2022; Pang et al. in J Clin Oncol 34:3992–3999, 2016; Lythgoe et al. in Prostate Cancer Prostatic Dis 24:1208–1211, 2021). Our long-term goal is to enroll and follow a cohort of historically under-represented cancer survivors, to better understand modifiable risk factors that influence clinical and quality of life outcomes in these populations. Towards that goal, we describe herein how we applied community-based participatory research approaches to develop inclusive study materials for enrolling such a cohort. Methods We implemented community engagement strategies to inform and enhance the study website and recruitment materials for this cohort including: hiring a dedicated engagement coordinator/community health educator as a member of our team; working with the Helen Diller Family Comprehensive Cancer Center Office of Community Engagement (OCE) and Community Advisory Board members; presenting our educational, research, and study recruitment materials at community events; and establishing a community advisory group specifically for the study (4 individuals). In parallel with these efforts, 20 semi-structured user testing interviews were conducted with diverse cancer survivors to inform the look, feel, and usability of the study website. Results Engagement with community members was a powerful and important approach for this study’s development. Feedback was solicited and used to inform decisions regarding the study name (eat move sleep, EMOVES), logo, study website content and imagery, and recruitment materials. Based on community feedback, we developed additional educational materials on healthy groceries and portion size in multiple languages and created a study video. Conclusions Including an engagement coordinator as a permanent team member, partnering with the institutional community outreach and engagement resources (i.e., OCE), and allocating dedicated time and financial support for cultivating relationships with stakeholders outside the university were critical to the development of the study website and materials. Our community guided strategies will be tested as we conduct enrollment through community advisor networks and via the state cancer registry.
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- 2023
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4. Correlates of Sexual Behavior Across Fatherhood Status: Finding From the National Longitudinal Study of Adolescent to Adult Health (Add Health), 2016–2018
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Samuel L. K. Baxter, Lorenzo N. Hopper, and Chelse Spinner
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Medicine - Abstract
Amid national trends in postponed parenthood and more diverse family structures, the fatherhood identity may be important to men’s sexual behaviors. This study examined factors associated with reports of consistent contraceptive use and multiple sexual partners across fatherhood status. Using public data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), Wave V (2016–2018), two sexual behaviors were examined among 1,163 men aged 32 to 42 years. Outcomes were two binary indicators: consistent contraceptive use with partner and having multiple (≥2) sexual partners in the past year. Fatherhood status was categorized as nonfather, resident father, and nonresident father. Demographic (e.g., race/ethnicity, education, income, and relationship type) and health-related (e.g., drinking, perceived stress, depressive symptoms, and insurance status) factors were considered. Logistic regression analysis produced odds ratios and 95% confidence intervals and were stratified by fatherhood categories. In the sample, 72% of men were resident fathers, 10% were nonresident fathers, and 18% were nonfathers; 28% reported consistent contraceptive use and 16% reported multiple sexual partners. For nonfathers, relationship type and race were associated with reporting multiple sexual partners. For resident fathers, relationship type was the crucial factor associated with consistent contraceptive use and reporting multiple sexual partners. In nonresident fathers, relationship type, education, and income were important factors to consistent contraceptive use and reporting multiple sexual partners. Key findings suggest that relationship type, income, and education are crucial factors to men’s sexual behavior. Heterogeneous effects were observed across fatherhood status. This study adds to limited research on fatherhood and sexual behavior among men transitioning from young adulthood to middle age.
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- 2024
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5. Observation, Radiotherapy, or Radical Prostatectomy for Localized Prostate Cancer: Survival Analysis in the United States
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Jang Hee Han, Annika Herlemann, Samuel L. Washington III, Peter E. Lonergan, Peter R. Carroll, Matthew R. Cooperberg, and Chang Wook Jeong
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observation ,prostatectomy ,prostatic neoplasms ,radiotherapy ,survival ,Medicine ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Purpose: Contemporary treatment strategies for localized prostate cancer (PCa) have been evolved over time. However, there is little data regarding survival outcomes based on initial treatment by risk group in this new era. This study aims to evaluate survival outcomes among men who underwent observation, radiotherapy, or radical prostatectomy for localized PCa using a population-based cohort. Materials and Methods: The Surveillance, Epidemiology, and End Results (SEER) prostate with watchful waiting dataset (2010– 2016) was used. We included men diagnosed with localized PCa and clinical stage T1c-2cN0M0. Other inclusion criteria were age 50–79 years, prostate-specific antigen (PSA) ≤50 ng/mL, and initial treatment with observation (active surveillance/ watchful waiting), radiotherapy, or radical prostatectomy. PCa risk was assessed using the D’Amico classification. The primary endpoint was overall survival. Secondary endpoints included PCa-specific survival. Inverse probability of treatment weighting (IPTW)-adjusted Cox proportional hazard regression and competing risk analysis were performed to assess outcomes. Results: After IPTW-adjusting, pseudo-population comprised 521,656 men (observation: 170,428, radiotherapy: 175,628, radical prostatectomy: 175,600) at a median 36.5 month follow-up. Observation demonstrated the lowest 5-year overall survival rate (91.6%) after IPTW-adjusting in comparison to radiotherapy (92.4%) and radical prostatectomy (96.1%, p
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- 2023
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6. Simultaneous LC–MS/MS method for the quantitation of Azithromycin, Hydroxychloroquine and its metabolites in SARS-CoV-2(−/ +) populations using dried blood spots
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Yashpal S. Chhonker, Wafaa N. Aldhafiri, Dhruvkumar Soni, Neerja Trivedi, Claire Steinbronn, Christine Johnson, Helen C. Stankiewicz Karita, Michael K. Paasche-Orlow, Ruanne Barnabas, Samuel L. Arnold, and Daryl J. Murry
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Medicine ,Science - Abstract
Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a global pandemic of coronavirus disease 2019 (COVID-19). Early in the pandemic, efforts were made to test the SARS-CoV-2 antiviral efficacy of repurposed medications that were already approved and available for other indications, including hydroxychloroquine (HCQ) and azithromycin (AZI). To reduce the risk of SARS-CoV-2 exposure for clinical-trial study participants and to conform with lockdowns and social distancing guidelines, biospecimen collection for HCQ and AZI included at-home dried blood spot (DBS) collection rather than standard venipuncture by trained clinicians. In this study, we developed and validated the first sensitive and selective simultaneous LC–MS/MS method to accurately quantitate the concentration of HCQ, HCQ metabolites (Desethylchloroquine [DCQ], Bisdesethylchloroquine [BDCQ], Monodesethylhydroxychloroquine [DHCQ]) and AZI extracted from DBS. The validated method was successfully applied for the quantification of over 2000 DBS specimens to evaluate the pharmacokinetic profile of AZI, HQC, and its metabolites. This new method has a small sample volume requirement (~ 10 µL), results in high sensitivity (1 ng/mL), and would facilitate remotely conducted therapeutic drug monitoring.
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- 2023
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7. Explainable ML models for a deeper insight on treatment decision for localized prostate cancer
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Jang Hee Han, Sungyup Lee, Byounghwa Lee, Ock-kee Baek, Samuel L. Washington, Annika Herlemann, Peter E. Lonergan, Peter R. Carroll, Chang Wook Jeong, and Matthew R. Cooperberg
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Medicine ,Science - Abstract
Abstract Although there are several decision aids for the treatment of localized prostate cancer (PCa), there are limitations in the consistency and certainty of the information provided. We aimed to better understand the treatment decision process and develop a decision-predicting model considering oncologic, demographic, socioeconomic, and geographic factors. Men newly diagnosed with localized PCa between 2010 and 2015 from the Surveillance, Epidemiology, and End Results Prostate with Watchful Waiting database were included (n = 255,837). We designed two prediction models: (1) Active surveillance/watchful waiting (AS/WW), radical prostatectomy (RP), and radiation therapy (RT) decision prediction in the entire cohort. (2) Prediction of AS/WW decisions in the low-risk cohort. The discrimination of the model was evaluated using the multiclass area under the curve (AUC). A plausible Shapley additive explanations value was used to explain the model’s prediction results. Oncological variables affected the RP decisions most, whereas RT was highly affected by geographic factors. The dependence plot depicted the feature interactions in reaching a treatment decision. The decision predicting model achieved an overall multiclass AUC of 0.77, whereas 0.74 was confirmed for the low-risk model. Using a large population-based real-world database, we unraveled the complex decision-making process and visualized nonlinear feature interactions in localized PCa.
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- 2023
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8. An Alzheimer’s disease category progression sub-grouping analysis using manifold learning on ADNI
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Dustin van der Haar, Ahmed Moustafa, Samuel L. Warren, Hany Alashwal, and Terence van Zyl
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Medicine ,Science - Abstract
Abstract Many current statistical and machine learning methods have been used to explore Alzheimer’s disease (AD) and its associated patterns that contribute to the disease. However, there has been limited success in understanding the relationship between cognitive tests, biomarker data, and patient AD category progressions. In this work, we perform exploratory data analysis of AD health record data by analyzing various learned lower dimensional manifolds to separate early-stage AD categories further. Specifically, we used Spectral embedding, Multidimensional scaling, Isomap, t-Distributed Stochastic Neighbour Embedding, Uniform Manifold Approximation and Projection, and sparse denoising autoencoder based manifolds on the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. We then determine the clustering potential of the learned embeddings and then determine if category sub-groupings or sub-categories can be found. We then used a Kruskal–sWallis H test to determine the statistical significance of the discovered AD subcategories. Our results show that the existing AD categories do exhibit sub-groupings, especially in mild cognitive impairment transitions in many of the tested manifolds, showing there may be a need for further subcategories to describe AD progression.
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- 2023
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9. Effects of a Powered Ankle-Foot Prosthesis and Physical Therapy on Function for Individuals With Transfemoral Limb Loss: Rationale, Design, and Protocol for a Multisite Clinical Trial
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Jason T Maikos, Alison L Pruziner, Brad D Hendershot, David V Herlihy, John M Chomack, Michael J Hyre, Samuel L Phillips, Alexis N Sidiropoulos, Christopher L Dearth, and Leif M Nelson
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Medicine ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
BackgroundPowered ankle-foot prosthetic devices can generate net positive mechanical work during gait, which mimics the physiological ankle. However, gait deviations can persist in individuals with transfemoral limb loss because of habit or lack of rehabilitation. Prosthetic research efforts favor the design or evaluation of prosthetic componentry and rarely incorporate any type of rehabilitation, despite evidence suggesting that it is critical for minimizing gait imbalances. Given the accelerated rate of innovation in prosthetics, there is a fundamental knowledge gap concerning how individuals with transfemoral limb loss should learn to correctly use powered ankle-foot devices for maximum functional benefit. Because of the recent advances in prosthetic technology, there is also a critical unmet need to develop guidelines for the prescription of advanced prosthetic devices that incorporate both physical and psychological components to identify appropriate candidates for advanced technology. ObjectiveThe primary goal of this investigation is to examine the roles of advanced prosthetic technology and a device-specific rehabilitative intervention on gait biomechanics, functional efficacy, and pain in individuals with transfemoral limb loss. The secondary goal is to develop preliminary rehabilitation guidelines for advanced lower limb prosthetic devices to minimize gait imbalances and maximize function and to establish preliminary guidelines for powered ankle-foot prosthetic prescription. MethodsThis prospective, multisite study will enroll 30 individuals with unilateral transfemoral limb loss. At baseline, participants will undergo a full gait analysis and assessment of function, neurocognition, cognitive load, subjective preferences, and pain using their current passive prosthesis. The participants will then be fitted with a powered ankle-foot device and randomized into 2 equal groups: a powered device with a device-specific rehabilitation intervention (group A) or a powered device with the current standard of practice (group B). Group A will undergo 4 weeks of device-specific rehabilitation. Group B will receive the current standard of practice, which includes basic device education but no further device-specific rehabilitation. Data collection procedures will then be repeated after 4 weeks and 8 weeks of powered ankle use. ResultsThis study was funded in September 2017. Enrollment began in September 2018. Data collection will conclude by March 2024. The initial dissemination of results is expected in August 2024. ConclusionsThe projected trends indicate that the number of individuals with limb loss will dramatically increase in the United States. The absence of effective, evidence-based interventions may make individuals with transfemoral limb loss more susceptible to increased secondary physical conditions and degenerative changes. With this expected growth, considerable resources will be required for prosthetic and rehabilitation services. Identifying potential mechanisms for correcting gait asymmetries, either through advanced prosthetic technology or rehabilitative interventions, can provide a benchmark for understanding the optimal treatment strategies for individuals with transfemoral limb loss. Trial RegistrationClinicalTrials.gov NCT03625921; https://clinicaltrials.gov/study/NCT03625921 International Registered Report Identifier (IRRID)DERR1-10.2196/53412
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- 2024
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10. Contribution of PEPFAR-Supported HIV and TB Molecular Diagnostic Networks to COVID-19 Testing Preparedness in 16 Countries
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Erin Rottinghaus Romano, Katrina Sleeman, Patricia Hall-Eidson, Clement Zeh, Ravikiran Bhairavabhotla, Guoqing Zhang, Amitabh Adhikari, George Alemnji, Yolanda Rebello Cardo, Ana Pinheiro, Barbara Pocongo, Laura T. Eno, Judith D. Shang, Clement B. Ndongmo, Hilda Rosario, Orquidea Moreno, Lucia Aurora De La Cruz De León, Peter Fonjungo, Constantin Kabwe, Steve Ahuke-Mundeke, Dan Gama, Sindisiwe Dlamini, Gugu Maphalala, Tefsay Abreha, Anne Purfield, Yared Tedla Gebrehiwot, Daniel Melese Desalegn, Frank Basiye, Jane Mwangi, Nancy Bowen, Yohannes Mengistu, Shirley Lecher, Elizabeth Kampira, Muluken Kaba, Joseph Bitilinyu-Bangoh, Gillian Masamha, Sofia Omar Viegas, R. Suzanne Beard, Gerhard van Rooyen, Andreas N. Shiningavamwe, McPaul I.J, Nnaemeka C. Iriemenam, Nwando Mba, Catherine Okoi, Joel Katoro, Dennis L Kenyi, Bior K. Bior, Christina Mwangi, Susan Nabadda, Pontiano Kaleebu, Samuel L. Yingst, Prisca Chikwanda, Levi Veri, Raivi Simbi, and Heather Alexander
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HIV ,tuberculosis ,SARS-CoV-2 ,laboratories ,molecular diagnostic techniques COVID-19 ,coronavirus disease ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
The US President’s Emergency Plan for AIDS Relief (PEPFAR) supports molecular HIV and tuberculosis diagnostic networks and information management systems in low- and middle-income countries. We describe how national programs leveraged these PEPFAR-supported laboratory resources for SARS-CoV-2 testing during the COVID-19 pandemic. We sent a spreadsheet template consisting of 46 indicators for assessing the use of PEPFAR-supported diagnostic networks for COVID-19 pandemic response activities during April 1, 2020, to March 31, 2021, to 27 PEPFAR-supported countries or regions. A total of 109 PEPFAR-supported centralized HIV viral load and early infant diagnosis laboratories and 138 decentralized HIV and TB sites reported performing SARS-CoV-2 testing in 16 countries. Together, these sites contributed to >3.4 million SARS-CoV-2 tests during the 1-year period. Our findings illustrate that PEPFAR-supported diagnostic networks provided a wide range of resources to respond to emergency COVID-19 diagnostic testing in 16 low- and middle-income countries.
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- 2022
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11. Trajectories of self-reported pain-related health outcomes and longitudinal effects on medication use in rheumatoid arthritis: a prospective cohort analysis using the Australian Rheumatology Association Database (ARAD)
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Rachelle Buchbinder, Bethan Richards, Lyn March, Catherine L Hill, Rachel Black, Marissa Lassere, Joanna Tieu, Susan Lester, Huai Leng Pisaniello, Oscar Russell, Claire Barrett, and Samuel L Whittle
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Medicine - Abstract
Objective To determine distinct trajectories of self-reported pain-related health status in rheumatoid arthritis (RA), their relationship with sociodemographic factors and medication use.Methods 988 Australian Rheumatology Association Database participants with RA (71% female, mean age 54 years, mean disease duration 2.3 years) were included. Distinct multi-trajectories over 15-year follow-up for five different self-reported pain-related health outcome measures (Health Assessment Questionnaire Disability Index, visual analogue scores for pain, arthritis, global health and the Assessment of Quality of Life utility index) were identified using latent variable discrete mixture modelling. Random effects models were used to determine associations with medication use and biologic therapy modification during follow-up.Results Four, approximately equally sized, pain/health status groups were identified, ranging from ‘better’ to ‘poorer’, within which changes over time were relatively small. Important determinants of those with poorer pain/health status included female gender, obesity, smoking, socioeconomic indicators and comorbidities. While biologic therapy use was similar between groups during follow-up, biologic therapy modifications (plinear
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- 2023
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12. The phylodynamics of SARS-CoV-2 during 2020 in Finland
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Phuoc Truong Nguyen, Ravi Kant, Frederik Van den Broeck, Maija T. Suvanto, Hussein Alburkat, Jenni Virtanen, Ella Ahvenainen, Robert Castren, Samuel L. Hong, Guy Baele, Maarit J. Ahava, Hanna Jarva, Suvi Tuulia Jokiranta, Hannimari Kallio-Kokko, Eliisa Kekäläinen, Vesa Kirjavainen, Elisa Kortela, Satu Kurkela, Maija Lappalainen, Hanna Liimatainen, Marc A. Suchard, Sari Hannula, Pekka Ellonen, Tarja Sironen, Philippe Lemey, Olli Vapalahti, and Teemu Smura
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Medicine - Abstract
Truong Nguyen, Kant, Van den Broeck et al. report the SARS-CoV-2 lineages circulating in Finland in 2020. Phylogeographic analysis suggests that 42 independent SARS-CoV-2 introductions into Finland occurred, with a single introduction seeding one third of cases in the spring.
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- 2022
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13. Criteria for Advanced Prosthetic Foot Prescription: Rationale, Design, and Protocol for a Multisite, Randomized Controlled Trial
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Jason T Maikos, Brad D Hendershot, Alison L Pruziner, Michael J Hyre, John M Chomack, Samuel L Phillips, Jeffrey T Heckman, Alexis N Sidiropoulos, Christopher L Dearth, and Leif M Nelson
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Medicine ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
BackgroundThe prescription of prosthetic ankle-foot devices is often based on the professional judgment of the limb loss care team or limited evidentiary research. Current prosthetic research efforts have focused on the design and development of prosthetic devices rather than on understanding which devices are the most appropriate to prescribe. This investigation will evaluate biomechanical, functional, and subjective outcome measures to help determine the optimal prescription parameters of prosthetic ankle-foot devices. ObjectiveThis study aims to develop evidence-based guidelines for limb loss care teams for the appropriate prescription of commercially available prosthetic ankle-foot devices to improve function and satisfaction. MethodsThis investigation will be a multisite, randomized, crossover clinical trial targeting the enrollment of 100 participants. Participants will use 3 different types of prosthetic devices (energy storing and returning, articulating, and powered) in random order. Participants will be fitted and trained with each device and then separately use each device for a 1-week acclimation period. Following each 1-week acclimation period, participants will be evaluated using several functional measures and subjective surveys. A random subset of participants (30/100, 30%) will also undergo full-body gait analysis, following each 1-week acclimation period, to collect biomechanical data during level ground and incline and decline walking. After all individual device evaluations, participants will be given all 3 prostheses concurrently for 4 weeks of home and community use to capture user preference. Activity monitoring and a guided interview will be used to determine overall user preference. ResultsThe study was funded in August 2017, and data collection began in 2018. Data collection is expected to be completed before July 2023. Initial dissemination of results is expected to occur in the winter of 2023. ConclusionsBy identifying biomechanical, functional, and subjective outcomes that are sensitive to differences in prosthetic ankle-foot devices, a benchmark of evidence can be developed to guide effective prosthetic prescription. Trial RegistrationClinicalTrials.gov NCT03505983; https://clinicaltrials.gov/ct2/show/NCT03505983 International Registered Report Identifier (IRRID)DERR1-10.2196/45612
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- 2023
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14. Expandable Sendai-Virus-Reprogrammed Human iPSC-Neuronal Precursors: Post-Grafting Safety Characterization in Rats and Adult Pig
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Yoshiomi Kobayashi, Michiko Shigyo, Oleksandr Platoshyn, Silvia Marsala, Tomohisa Kato, Naoki Takamura, Kenji Yoshida, Akiyoshi Kishino, Mariana Bravo-Hernandez, Stefan Juhas, Jana Juhasova, Hana Studenovska, Vladimir Proks, Shawn P. Driscoll, Thomas D. Glenn, Samuel L. Pfaff, Joseph D. Ciacci, and Martin Marsala
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Medicine - Abstract
One of the challenges in clinical translation of cell-replacement therapies is the definition of optimal cell generation and storage/recovery protocols which would permit a rapid preparation of cell-treatment products for patient administration. Besides, the availability of injection devices that are simple to use is critical for potential future dissemination of any spinally targeted cell-replacement therapy into general medical practice. Here, we compared the engraftment properties of established human-induced pluripotent stem cells (hiPSCs)-derived neural precursor cell (NPCs) line once cells were harvested fresh from the cell culture or previously frozen and then grafted into striata or spinal cord of the immunodeficient rat. A newly developed human spinal injection device equipped with a spinal cord pulsation-cancelation magnetic needle was also tested for its safety in an adult immunosuppressed pig. Previously frozen NPCs showed similar post-grafting survival and differentiation profile as was seen for freshly harvested cells. Testing of human injection device showed acceptable safety with no detectable surgical procedure or spinal NPCs injection-related side effects.
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- 2023
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15. Which clinical research questions are the most important? Development and preliminary validation of the Australia & New Zealand Musculoskeletal (ANZMUSC) Clinical Trials Network Research Question Importance Tool (ANZMUSC-RQIT).
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William J Taylor, Robin Willink, Denise A O'Connor, Vinay Patel, Allison Bourne, Ian A Harris, Samuel L Whittle, Bethan Richards, Ornella Clavisi, Sally Green, Rana S Hinman, Chris G Maher, Ainslie Cahill, Annie McPherson, Charlotte Hewson, Suzie E May, Bruce Walker, Philip C Robinson, Davina Ghersi, Jane Fitzpatrick, Tania Winzenberg, Kieran Fallon, Paul Glasziou, Laurent Billot, and Rachelle Buchbinder
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Medicine ,Science - Abstract
Background and aimsHigh quality clinical research that addresses important questions requires significant resources. In resource-constrained environments, projects will therefore need to be prioritized. The Australia and New Zealand Musculoskeletal (ANZMUSC) Clinical Trials Network aimed to develop a stakeholder-based, transparent, easily implementable tool that provides a score for the 'importance' of a research question which could be used to rank research projects in order of importance.MethodsUsing a mixed-methods, multi-stage approach that included a Delphi survey, consensus workshop, inter-rater reliability testing, validity testing and calibration using a discrete-choice methodology, the Research Question Importance Tool (ANZMUSC-RQIT) was developed. The tool incorporated broad stakeholder opinion, including consumers, at each stage and is designed for scoring by committee consensus.ResultsThe ANZMUSC-RQIT tool consists of 5 dimensions (compared to 6 dimensions for an earlier version of RQIT): (1) extent of stakeholder consensus, (2) social burden of health condition, (3) patient burden of health condition, (4) anticipated effectiveness of proposed intervention, and (5) extent to which health equity is addressed by the research. Each dimension is assessed by defining ordered levels of a relevant attribute and by assigning a score to each level. The scores for the dimensions are then summed to obtain an overall ANZMUSC-RQIT score, which represents the importance of the research question. The result is a score on an interval scale with an arbitrary unit, ranging from 0 (minimal importance) to 1000. The ANZMUSC-RQIT dimensions can be reliably ordered by committee consensus (ICC 0.73-0.93) and the overall score is positively associated with citation count (standardised regression coefficient 0.33, pConclusionWe propose that the ANZMUSC-RQIT is a useful tool for prioritising the importance of a research question.
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- 2023
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16. dSmad2 differentially regulates dILP2 and dILP5 in insulin producing and circadian pacemaker cells in unmated adult females.
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Samuel L Goldsmith and Stuart J Newfeld
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Medicine ,Science - Abstract
Much is known about environmental influences on metabolism and systemic insulin levels. Less is known about how those influences are translated into molecular mechanisms regulating insulin production. To better understand the molecular mechanisms we generated marked cells homozygous for a null mutation in the Drosophila TGF-β signal transducer dSmad2 in unmated adult females. We then conducted side-by-side single cell comparisons of the pixel intensity of two Drosophila insulin-like peptides (dILP2 and dILP5) in dSmad2- mutant and wild type insulin producing cells (IPCs). The analysis revealed multiple features of dSmad2 regulation of dILPs. In addition, we discovered that dILP5 is expressed and regulated by dSmad2 in circadian pacemaker cells (CPCs). Outcomes of regulation by dSmad2 differ between dILP2 and dILP5 within IPCs and differ for dILP5 between IPCs and CPCs. Modes of dSmad2 regulation differ between dILP2 and dILP5. dSmad2 antagonism of dILP2 in IPCs is robust but dSmad2 regulation of dILP5 in IPCs and CPCs toggles between antagonism and agonism depending upon dSmad2 dosage. Companion studies of dILP2 and dILP5 in the IPCs of dCORL mutant (fussel in Flybase and SKOR in mammals) and upd2 mutant unmated adult females showed no significant difference from wild type. Taken together, the data suggest that dSmad2 regulates dILP2 and dILP5 via distinct mechanisms in IPCs (antagonist) and CPCs (agonist) and in unmated adult females that dSmad2 acts independently of dCORL and upd2.
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- 2023
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17. Spinal premotor interneurons controlling antagonistic muscles are spatially intermingled
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Remi Ronzano, Sophie Skarlatou, Bianca K Barriga, B Anne Bannatyne, Gardave Singh Bhumbra, Joshua D Foster, Jeffrey D Moore, Camille Lancelin, Amanda M Pocratsky, Mustafa Görkem Özyurt, Calvin Chad Smith, Andrew J Todd, David J Maxwell, Andrew J Murray, Samuel L Pfaff, Robert M Brownstone, Niccolò Zampieri, and Marco Beato
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spinal cord ,premotor interneurons ,rabies viral tracing ,flexor muscles ,extensor muscles ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Elaborate behaviours are produced by tightly controlled flexor-extensor motor neuron activation patterns. Motor neurons are regulated by a network of interneurons within the spinal cord, but the computational processes involved in motor control are not fully understood. The neuroanatomical arrangement of motor and premotor neurons into topographic patterns related to their controlled muscles is thought to facilitate how information is processed by spinal circuits. Rabies retrograde monosynaptic tracing has been used to label premotor interneurons innervating specific motor neuron pools, with previous studies reporting topographic mediolateral positional biases in flexor and extensor premotor interneurons. To more precisely define how premotor interneurons contacting specific motor pools are organized, we used multiple complementary viral-tracing approaches in mice to minimize systematic biases associated with each method. Contrary to expectations, we found that premotor interneurons contacting motor pools controlling flexion and extension of the ankle are highly intermingled rather than segregated into specific domains like motor neurons. Thus, premotor spinal neurons controlling different muscles process motor instructions in the absence of clear spatial patterns among the flexor-extensor circuit components.
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- 2022
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18. Deglacial patterns of South Pacific overturning inferred from 231Pa and 230Th
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Thomas A. Ronge, Jörg Lippold, Walter Geibert, Samuel L. Jaccard, Sebastian Mieruch-Schnülle, Finn Süfke, and Ralf Tiedemann
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Medicine ,Science - Abstract
Abstract The millennial-scale variability of the Atlantic Meridional Overturning Circulation (AMOC) is well documented for the last glacial termination and beyond. Despite its importance for the climate system, the evolution of the South Pacific overturning circulation (SPOC) is by far less well understood. A recently published study highlights the potential applicability of the 231Pa/230Th-proxy in the Pacific. Here, we present five sedimentary down-core profiles of 231Pa/230Th-ratios measured on a depth transect from the Pacific sector of the Southern Ocean to test this hypothesis using downcore records. Our data are consistent with an increase in SPOC as early as 20 ka that peaked during Heinrich Stadial 1. The timing indicates that the SPOC did not simply react to AMOC changes via the bipolar seesaw but were triggered via Southern Hemisphere processes.
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- 2021
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19. Exploiting genomic surveillance to map the spatio-temporal dispersal of SARS-CoV-2 spike mutations in Belgium across 2020
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Nena Bollen, Maria Artesi, Keith Durkin, Samuel L. Hong, Barney Potter, Bouchra Boujemla, Bert Vanmechelen, Joan Martí-Carreras, Tony Wawina-Bokalanga, Cécile Meex, Sébastien Bontems, Marie-Pierre Hayette, Emmanuel André, Piet Maes, Vincent Bours, Guy Baele, and Simon Dellicour
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Medicine ,Science - Abstract
Abstract At the end of 2020, several new variants of SARS-CoV-2—designated variants of concern—were detected and quickly suspected to be associated with a higher transmissibility and possible escape of vaccine-induced immunity. In Belgium, this discovery has motivated the initiation of a more ambitious genomic surveillance program, which is drastically increasing the number of SARS-CoV-2 genomes to analyse for monitoring the circulation of viral lineages and variants of concern. In order to efficiently analyse the massive collection of genomic data that are the result of such increased sequencing efforts, streamlined analytical strategies are crucial. In this study, we illustrate how to efficiently map the spatio-temporal dispersal of target mutations at a regional level. As a proof of concept, we focus on the Belgian province of Liège that has been consistently sampled throughout 2020, but was also one of the main epicenters of the second European epidemic wave. Specifically, we employ a recently developed phylogeographic workflow to infer the regional dispersal history of viral lineages associated with three specific mutations on the spike protein (S98F, A222V and S477N) and to quantify their relative importance through time. Our analytical pipeline enables analysing large data sets and has the potential to be quickly applied and updated to track target mutations in space and time throughout the course of an epidemic.
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- 2021
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20. Hospital trajectories and early predictors of clinical outcomes differ between SARS-CoV-2 and influenza pneumonia
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Patrick G. Lyons, Sivasubramanium V. Bhavani, Aaloke Mody, Alice Bewley, Katherine Dittman, Aisling Doyle, Samuel L. Windham, Tej M. Patel, Bharat Neelam Raju, Matthew Keller, Matthew M. Churpek, Carolyn S. Calfee, Andrew P. Michelson, Thomas Kannampallil, Elvin H. Geng, and Pratik Sinha
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Viral pneumonia ,SARS-CoV-2 ,Influenza ,Hospital outcomes ,Statistical modelling ,Medicine ,Medicine (General) ,R5-920 - Abstract
Summary: Background: A comparison of pneumonias due to SARS-CoV-2 and influenza, in terms of clinical course and predictors of outcomes, might inform prognosis and resource management. We aimed to compare clinical course and outcome predictors in SARS-CoV-2 and influenza pneumonia using multi-state modelling and supervised machine learning on clinical data among hospitalised patients. Methods: This multicenter retrospective cohort study of patients hospitalised with SARS-CoV-2 (March-December 2020) or influenza (Jan 2015-March 2020) pneumonia had the composite of hospital mortality and hospice discharge as the primary outcome. Multi-state models compared differences in oxygenation/ventilatory utilisation between pneumonias longitudinally throughout hospitalisation. Differences in predictors of outcome were modelled using supervised machine learning classifiers. Findings: Among 2,529 hospitalisations with SARS-CoV-2 and 2,256 with influenza pneumonia, the primary outcome occurred in 21% and 9%, respectively. Multi-state models differentiated oxygen requirement progression between viruses, with SARS-CoV-2 manifesting rapidly-escalating early hypoxemia. Highly contributory classifier variables for the primary outcome differed substantially between viruses. Interpretation: SARS-CoV-2 and influenza pneumonia differ in presentation, hospital course, and outcome predictors. These pathogen-specific differential responses in viral pneumonias suggest distinct management approaches should be investigated. Funding: This project was supported by NIH/NCATS UL1 TR002345, NIH/NCATS KL2 TR002346 (PGL), the Doris Duke Charitable Foundation grant 2015215 (PGL), NIH/NHLBI R35 HL140026 (CSC), and a Big Ideas Award from the BJC HealthCare and Washington University School of Medicine Healthcare Innovation Lab and NIH/NIGMS R35 GM142992 (PS).
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- 2022
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21. Implementation of a Leave-behind Naloxone Program in San Francisco: A One-year Experience
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Kathy T. LeSaint, Juan Carlos C. Montoy, Eric C. Silverman, Maria C. Raven, Samuel L. Schow, Phillip O. Coffin, John F. Brown, and Mary P. Mercer
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Medicine ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Introduction: In response to the ongoing opioid overdose crisis, US officials urged the expansion of access to naloxone for opioid overdose reversal. Since then, emergency medical services’ (EMS) dispensing of naloxone kits has become an emerging harm reduction strategy. Methods: We created a naloxone training and low-barrier distribution program in San Francisco: Project FRIEND (First Responder Increased Education and Naloxone Distribution). The team assembled an advisory committee of stakeholders and subject-matter experts, worked with local and state EMS agencies to augment existing protocols, created training curricula, and developed a naloxone-distribution data collection system. Naloxone kits were labeled for registration and data tracking. Emergency medical technicians and paramedics were asked to distribute naloxone kits to any individuals (patient or bystander) they deemed at risk of experiencing or witnessing an opioid overdose, and to voluntarily register those kits. Results: Training modalities included a video module (distributed to over 700 EMS personnel) and voluntary, in-person training sessions, attended by 224 EMS personnel. From September 25, 2019–September 24, 2020, 1,200 naloxone kits were distributed to EMS companies. Of these, 232 kits (19%) were registered by EMS personnel. Among registered kits, 146 (63%) were distributed during encounters for suspected overdose, and 103 (44%) were distributed to patients themselves. Most patients were male (n = 153, 66%) and of White race (n = 124, 53%); median age was 37.5 years (interquartile range 31–47). Conclusion: We describe a successful implementation and highlight the feasibility of a low-threshold, leave-behind naloxone program. Collaboration with multiple entities was a key component of the program’s success.
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- 2022
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22. Mobile Health Tobacco Cessation Interventions to Promote Health Equity: Current Perspectives
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Samuel L. Battalio, Angela F. Pfammatter, Kiarri N. Kershaw, Alexis Hernandez, David E. Conroy, and Bonnie Spring
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disparities (health ,mHealth (mobile health) ,tobacco and tobacco product ,cessation ,disparities (health racial) ,Medicine ,Public aspects of medicine ,RA1-1270 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Although US tobacco use trends show overall improvement, social disadvantage continues to drive significant disparities. Traditional tobacco cessation interventions and public policy initiatives have failed to equitably benefit socially-disadvantaged populations. Advancements in mobile digital technologies have created new opportunities to develop resource-efficient mobile health (mHealth) interventions that, relative to traditional approaches, have greater reach while still maintaining comparable or greater efficacy. Their potential for affordability, scalability, and efficiency gives mHealth tobacco cessation interventions potential as tools to help redress tobacco use disparities. We discuss our perspectives on the state of the science surrounding mHealth tobacco cessation interventions for use by socially-disadvantaged populations. In doing so, we outline existing models of health disparities and social determinants of health (SDOH) and discuss potential ways that mHealth interventions might be optimized to offset or address the impact of social determinants of tobacco use. Because smokers from socially-disadvantaged backgrounds face multi-level barriers that can dynamically heighten the risks of tobacco use, we discuss cutting-edge mHealth interventions that adapt dynamically based on context. We also consider complications and pitfalls that could emerge when designing, evaluating, and implementing mHealth tobacco cessation interventions for socially-disadvantaged populations. Altogether, this perspective article provides a conceptual foundation for optimizing mHealth tobacco cessation interventions for the socially-disadvantaged populations in greatest need.
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- 2022
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23. Transmission of Multidrug-Resistant Salmonella enterica Subspecies enterica 4,[5],12:i:- Sequence Type 34 between Europe and the United States
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Ehud Elnekave, Samuel L. Hong, Seunghyun Lim, Dave Boxrud, Albert Rovira, Alison E. Mather, Andres Perez, and Julio Alvarez
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Evolution ,Salmonella monophasic ,Salmonella enterica subspecies enterica ,serotype 4,[5],12:i:- ,multidrug-resistance ,antimicrobial resistance ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Multidrug-resistant Salmonella enterica subspecies enterica 4,[5],12:i:- sequence type 34 represents a worldwide public health risk. To determine its origin in the United States, we reconstructed a time-scaled phylogeny with a discrete trait geospatial model. The clone in the United States was introduced from Europe on multiple occasions in the early 2000s.
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- 2020
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24. Socio-cognitive factors influencing access to HIV prevention services among people who inject drugs in Dar es Salaam, Tanzania: An integrated bio-behavioural survey.
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Samuel L Likindikoki, Dan W Meyrowitsch, Mucho M Mizinduko, Alexander M Ishungisa, Britt P Tersbøl, Germana H Leyna, Kåre Moen, Neema Makyao, Theis Lange, Melkizedeck T Leshabari, and Elia J Mmbaga
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Medicine ,Science - Abstract
IntroductionPeople who inject drugs (PWID) in Sub-Saharan Africa have limited access to comprehensive HIV services. While it is important to inform programming, knowledge about factors influencing access to comprehensive HIV services is scarce. We assessed the proportions of PWID with access to HIV prevention services and associated socio-cognitive factors in Tanzania.MethodsA cross-sectional survey was conducted among PWID between October and December 2017 in Dar es Salaam, Tanzania. Data on access to HIV prevention services, demographics and selected socio-cognitive factors were collected through structured face-to-face interviews. Weighted descriptive and forward selection multivariable logistics regression analyses were done to assess independent associations between HIV prevention services and predictors of interest. The results were two tailed and a p-value of less than 0.05 was considered statistically significant.ResultsThe study included 611 PWID (males: 94.4%) with a median age of 34 years (Interquartile Range (IQR), 29-38). A large majority of participants reported to have access to condoms (87.8%), sterile needles/syringes (72.8%) and ever tested for HIV (66.0%). About half (52.0%) reported to have used condoms in the past one month and about a third (28.5%) accessed a peer educator. The odds of testing for HIV decreased among participants who perceived their HIV risk to be high (aOR = 0.29; 95%CI: 0.17-0.49) and those experienced sexual violence (aOR = 0.60; 95%CI 0.37-0.98). However, the odds of testing for HIV increased among participants with secondary level of education (aOR = 2.16; 95%CI: 1.06-5.55), and those who reported having correct comprehensive HIV knowledge (CCHK) (aOR = 1.63; 95%CI 1.12-2.41). The odds of access to condoms increased among females (aOR = 2.23; 95%CI: 1.04-5.02) but decreased among participants with secondary level of education (aOR = 0.41; 95%CI: 0.19-0.84), an income of >TZS 200,000 (aOR = 0.39; 95%CI: 0.23-0.66) and those who perceived their HIV risk to be high (aOR = 0.13; 95%CI: 0.03-0.36). The odds of access to peer educators was higher among participants with primary (aOR = 1.61; 95%CI: 1.01-2.26), and secondary (aOR = 2.71; 95%CI: 1.39-5.33) levels of education. The odds of access to sterile needle and syringe decreased among participants who perceived their HIV risk to be high (aOR = 0.11;95%CI 0.05-0.22), and low-medium (aOR = 0.25;95%CI 0.11-0.52) but increased among those with primary level of education (aOR = 1.72;95%CI 1.06-2.78).ConclusionAccess to condom, HIV testing, sterile needles and syringes were relatively high among PWID. However, condom use and access to peer educators was relatively low. HIV knowledge and risk perception, gender, education, and sexual violence influenced access to HIV prevention services. There is an urgent need to address the identified socio-cognitive factors and scale up all aspects of HIV prevention services to fast-track attainment of the 2025 UNAIDS goals and ending the HIV epidemic.
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- 2022
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25. Oxidation states of copper in preservative treated wood as studied by X-ray absorption near edge spectroscopy (XANES).
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Samuel L Zelinka, Grant T Kirker, George E Sterbinsky, and Keith J Bourne
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Medicine ,Science - Abstract
Copper is a common component in wood preservatives and is used to protect the wood against fungal degradation. Previous research has shown that the Cu++ oxidation state provides the best wood protection, and Cu++ is widely believed to be the oxidation state of most copper within treated wood. A recent study using X-ray absorption near edge spectroscopy (XANES) reported high amounts of Cu+ in wood that had been in contact with corroded fasteners. This study uses XANES to examine the copper oxidation states in wood treated with several different wood preservatives as a function of time after treatment. In contrast with previous literature which focused on the fixation reaction in the first few hours after treatment, this paper examines the oxidation state of Cu in treated wood at longer times (up to 1-year) after treatment. The results showed in nearly all cases, Cu was in the Cu++ oxidation state to within the measurement uncertainty. Cu XANES patterns taken approximately 1-year after treatment showed no discernable differences between preservative systems, indicating that regardless of the starting treatment the final Cu speciation is the same within one year. The results confirm previously held beliefs about the Cu oxidation states in wood and give further insights into the corrosion mechanism of metals embedded in treated wood.
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- 2022
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26. Contrat unique, une approche innovante de financement du niveau intermédiaire du système de santé en République Démocratique du Congo : processus et défis de mise en œuvre
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Ghislain Bisimwa, Samuel L. Makali, Hermes Karemere, Christian Molima, Raphael Nunga, Alain Iyeti, and Faustin Chenge
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financing ,health system ,basket fund ,intermediate level ,drc ,Medicine ,Public aspects of medicine ,RA1-1270 - Abstract
Basket fund, an innovative approach for intermediate health system level financing in the Democratic Republic of Congo: Implementation process and challenges. Background: Universal health coverage should allow countries to establish a financing strategy in order to guarantee the health of the population. Aim: Our objective was to describe the process and preliminary results of the implementation of the basket fund approach as a mode of financing the intermediate level (provincial health divisions) of the Congolese health system. Setting: The study was conducted in the provincial health divisions (PHDs), representing the intermediate level of the health system in the Democratic Republic of Congo, where the basket fund approach has been implemented Methods: We conducted a mixed-methods convergent study as part of the evaluation of the basket fund approach in the Democratic Republic of Congo, five years after its introduction (2014–2019). Data was collected through a document review and individual interviews by telephone. A descriptive analysis of the quantitative data was conducted using Statistical Package for Social Sciences (SPSS) version 24 software. The qualitative data were analysed by thematic analysis using a pre-established thematic framework. Results: The implementation of the basket fund approach was effective in some (PHDs) (53.8% in 2016). The operating costs of the PHDs varied according to the size, density and number of health zones covered. In the PHDs where the basket fund was operational, this approach appeared to contribute to improved planning and management in the use of resources, the partnership between technical and financial partners (TFPs and PHDs) and incentives for the performance of PHD agents. Conclusion: In the DRC, the basket fund approach has contributed to improved collaboration between donors in the health sector and facilitated the decentralisation of funding planning to the provincial level.
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- 2021
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27. Characterising the long-term clinical outcomes of 1190 hospitalised patients with COVID-19 in New York City: a retrospective case series
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Michael T Yin, Ruijun Chen, George Hripcsak, Magdalena E Sobieszczyk, Sherif M Shoucri, Lawrence Purpura, Clare DeLaurentis, Matthew A Adan, Deborah A Theodore, Alexandria Lauren Irace, Shelief Y Robbins-Juarez, Apurva M Khedagi, Daniel Letchford, Amro A Harb, Lillian M Zerihun, Kate E Lee, Karen Gambina, Max C Lauring, Noah Chen, Colin P Sperring, Sanket S Mehta, Ellen L Myers, Hueyjong Shih, Michael G Argenziano, Samuel L Bruce, Cody L Slater, Jonathan R Tiao, Karthik Natarajan, Delivette Castor, and Jason E Zucker
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Medicine - Abstract
Objective To characterise the long-term outcomes of patients with COVID-19 admitted to a large New York City medical centre at 3 and 6 months after hospitalisation and describe their healthcare usage, symptoms, morbidity and mortality.Design Retrospective cohort through manual chart review of the electronic medical record.Setting NewYork-Presbyterian/Columbia University Irving Medical Center, a quaternary care academic medical centre in New York City.Participants The first 1190 consecutive patients with symptoms of COVID-19 who presented to the hospital for care between 1 March and 8 April 2020 and tested positive for SARS-CoV-2 on reverse transcriptase PCR assay.Main outcome measures Type and frequency of follow-up encounters, self-reported symptoms, morbidity and mortality at 3 and 6 months after presentation, respectively; patient disposition information prior to admission, at discharge, and at 3 and 6 months after hospital presentation.Results Of the 1190 reviewed patients, 929 survived their initial hospitalisation and 261 died. Among survivors, 570 had follow-up encounters (488 at 3 months and 364 at 6 months). An additional 33 patients died in the follow-up period. In the first 3 months after admission, most encounters were telehealth visits (59%). Cardiopulmonary symptoms (35.7% and 28%), especially dyspnoea (22.1% and 15.9%), were the most common reported symptoms at 3-month and 6-month encounters, respectively. Additionally, a large number of patients reported generalised (26.4%) or neuropsychiatric (24.2%) symptoms 6 months after hospitalisation. Patients with severe COVID-19 were more likely to have reduced mobility, reduced independence or a new dialysis requirement in the 6 months after hospitalisation.Conclusions Patients hospitalised with SARS-CoV-2 infection reported persistent symptoms up to 6 months after diagnosis. These results highlight the long-term morbidity of COVID-19 and its burden on patients and healthcare resources.
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- 2021
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28. SARS-CoV-2 detection and genomic sequencing from hospital surface samples collected at UC Davis.
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David A Coil, Timothy Albertson, Shefali Banerjee, Greg Brennan, A J Campbell, Stuart H Cohen, Satya Dandekar, Samuel L Díaz-Muñoz, Jonathan A Eisen, Tracey Goldstein, Ivy R Jose, Maya Juarez, Brandt A Robinson, Stefan Rothenburg, Christian Sandrock, Ana M M Stoian, Daniel G Tompkins, Alexandre Tremeau-Bravard, and Angela Haczku
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Medicine ,Science - Abstract
RationaleThere is little doubt that aerosols play a major role in the transmission of SARS-CoV-2. The significance of the presence and infectivity of this virus on environmental surfaces, especially in a hospital setting, remains less clear.ObjectivesWe aimed to analyze surface swabs for SARS-CoV-2 RNA and infectivity, and to determine their suitability for sequence analysis.MethodsSamples were collected during two waves of COVID-19 at the University of California, Davis Medical Center, in COVID-19 patient serving and staff congregation areas. qRT-PCR positive samples were investigated in Vero cell cultures for cytopathic effects and phylogenetically assessed by whole genome sequencing.Measurements and main resultsImproved cleaning and patient management practices between April and August 2020 were associated with a substantial reduction of SARS-CoV-2 qRT-PCR positivity (from 11% to 2%) in hospital surface samples. Even though we recovered near-complete genome sequences in some, none of the positive samples (11 of 224 total) caused cytopathic effects in cultured cells suggesting this nucleic acid was either not associated with intact virions, or they were present in insufficient numbers for infectivity. Phylogenetic analysis suggested that the SARS-CoV-2 genomes of the positive samples were derived from hospitalized patients. Genomic sequences isolated from qRT-PCR negative samples indicate a superior sensitivity of viral detection by sequencing.ConclusionsThis study confirms the low likelihood that SARS-CoV-2 contamination on hospital surfaces contains infectious virus, disputing the importance of fomites in COVID-19 transmission. Ours is the first report on recovering near-complete SARS-CoV-2 genome sequences directly from environmental surface swabs.
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- 2021
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29. A model for focal seizure onset, propagation, evolution, and progression
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Jyun-you Liou, Elliot H Smith, Lisa M Bateman, Samuel L Bruce, Guy M McKhann, Robert R Goodman, Ronald G Emerson, Catherine A Schevon, and LF Abbott
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epilepsy ,seizure models ,traveling waves ,focal seizure ,synaptic plasticity ,EEG ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
We developed a neural network model that can account for major elements common to human focal seizures. These include the tonic-clonic transition, slow advance of clinical semiology and corresponding seizure territory expansion, widespread EEG synchronization, and slowing of the ictal rhythm as the seizure approaches termination. These were reproduced by incorporating usage-dependent exhaustion of inhibition in an adaptive neural network that receives global feedback inhibition in addition to local recurrent projections. Our model proposes mechanisms that may underline common EEG seizure onset patterns and status epilepticus, and postulates a role for synaptic plasticity in the emergence of epileptic foci. Complex patterns of seizure activity and bi-stable seizure end-points arise when stochastic noise is included. With the rapid advancement of clinical and experimental tools, we believe that this model can provide a roadmap and potentially an in silico testbed for future explorations of seizure mechanisms and clinical therapies.
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- 2020
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30. Racial discrimination in medical care settings and opioid pain reliever misuse in a U.S. cohort: 1992 to 2015.
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Samuel L Swift, M Maria Glymour, Tali Elfassy, Cora Lewis, Catarina I Kiefe, Stephen Sidney, Sebastian Calonico, Daniel Feaster, Zinzi Bailey, and Adina Zeki Al Hazzouri
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Medicine ,Science - Abstract
BackgroundIn the United States whites are more likely to misuse opioid pain relievers (OPRs) than blacks, and blacks are less likely to be prescribed OPRs than whites. Our objective is to determine whether racial discrimination in medical settings is protective for blacks against OPR misuse, thus mediating the black-white disparities in OPR misuse.MethodsWe used data from 3528 black and white adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study, an ongoing multi-site cohort. We employ causal mediation methods, with race (black vs white) as the exposure, lifetime discrimination in medical settings prior to year 2000 as the mediator, and OPR misuse after 2000 as the outcome.ResultsWe found black participants were more likely to report discrimination in a medical setting (20.3% vs 0.9%) and less likely to report OPR misuse (5.8% vs 8.0%, OR = 0.71, 95% CI = 0.55, 0.93, adjusted for covariates). Our mediation models suggest that when everyone is not discriminated against, the disparity is wider with black persons having even lower odds of reporting OPR misuse (OR = 0.63, 95% CI = 0.45, 0.89) compared to their white counterparts, suggesting racial discrimination in medical settings is a risk factor for OPR misuse rather than protective.ConclusionsThese results suggest that racial discrimination in a medical setting is a risk factor for OPR misuse rather than being protective, and thus could not explain the seen black-white disparity in OPR misuse.
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- 2019
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31. Associations between erythrocyte polymorphisms and risks of uncomplicated and severe malaria in Ugandan children: A case control study.
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Arthur Mpimbaza, Andrew Walakira, Grace Ndeezi, Anne Katahoire, Charles Karamagi, Samuel L Nsobya, Stephen Tukwasibwe, Victor Asua, and Philip J Rosenthal
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Medicine ,Science - Abstract
BACKGROUND:Evidence for association between sickle cell and alpha thalassemia trait and severe malaria is compelling. However, for these polymorphisms associations with uncomplicated malaria, and for G6PD deficiency associations with uncomplicated and severe malaria, findings have been inconsistent. We studied samples from a three-arm case-control study with the objective of determining associations between common host erythrocyte polymorphisms and both uncomplicated and severe malaria, including different severe malaria phenotypes. METHOD:We assessed hemoglobin abnormalities, α-thalassemia, and G6PD deficiency by molecular methods in 325 children with severe malaria age-matched to 325 children with uncomplicated malaria and 325 healthy community controls. Conditional logistic regression was used to measure associations between specified genotypes and malaria outcomes. RESULTS:No tested polymorphisms offered significant protection against uncomplicated malaria. α-thalassemia homozygotes (_α/_α) had increased risk of uncomplicated malaria (OR 2.40; 95%CI 1.15, 5.03, p = 0.020). HbAS and α-thalassemia heterozygous (_α/αα) genotypes protected against severe malaria compared to uncomplicated malaria (HbAS OR 0.46; 0.23, 0.95, p = 0.036; _α/αα OR 0.51; 0.24, 0.77; p = 0.001) or community (HbAS OR 0.23; 0.11, 0.50; p
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- 2018
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32. Speed and segmentation control mechanisms characterized in rhythmically-active circuits created from spinal neurons produced from genetically-tagged embryonic stem cells
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Matthew J Sternfeld, Christopher A Hinckley, Niall J Moore, Matthew T Pankratz, Kathryn L Hilde, Shawn P Driscoll, Marito Hayashi, Neal D Amin, Dario Bonanomi, Wesley D Gifford, Kamal Sharma, Martyn Goulding, and Samuel L Pfaff
- Subjects
circuitoid ,synthetic network ,excitatory-inhibitory balance ,embryonic stem cells ,rhythmicity ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Flexible neural networks, such as the interconnected spinal neurons that control distinct motor actions, can switch their activity to produce different behaviors. Both excitatory (E) and inhibitory (I) spinal neurons are necessary for motor behavior, but the influence of recruiting different ratios of E-to-I cells remains unclear. We constructed synthetic microphysical neural networks, called circuitoids, using precise combinations of spinal neuron subtypes derived from mouse stem cells. Circuitoids of purified excitatory interneurons were sufficient to generate oscillatory bursts with properties similar to in vivo central pattern generators. Inhibitory V1 neurons provided dual layers of regulation within excitatory rhythmogenic networks - they increased the rhythmic burst frequency of excitatory V3 neurons, and segmented excitatory motor neuron activity into sub-networks. Accordingly, the speed and pattern of spinal circuits that underlie complex motor behaviors may be regulated by quantitatively gating the intra-network cellular activity ratio of E-to-I neurons.
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- 2017
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33. A statistical model for monitoring shell disease in inshore lobster fisheries: A case study in Long Island Sound.
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Kisei R Tanaka, Samuel L Belknap, Jared J Homola, and Yong Chen
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Medicine ,Science - Abstract
The expansion of shell disease is an emerging threat to the inshore lobster fisheries in the northeastern United States. The development of models to improve the efficiency and precision of existing monitoring programs is advocated as an important step in mitigating its harmful effects. The objective of this study is to construct a statistical model that could enhance the existing monitoring effort through (1) identification of potential disease-associated abiotic and biotic factors, and (2) estimation of spatial variation in disease prevalence in the lobster fishery. A delta-generalized additive modeling (GAM) approach was applied using bottom trawl survey data collected from 2001-2013 in Long Island Sound, a tidal estuary between New York and Connecticut states. Spatial distribution of shell disease prevalence was found to be strongly influenced by the interactive effects of latitude and longitude, possibly indicative of a geographic origin of shell disease. Bottom temperature, bottom salinity, and depth were also important factors affecting the spatial variability in shell disease prevalence. The delta-GAM projected high disease prevalence in non-surveyed locations. Additionally, a potential spatial discrepancy was found between modeled disease hotspots and survey-based gravity centers of disease prevalence. This study provides a modeling framework to enhance research, monitoring and management of emerging and continuing marine disease threats.
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- 2017
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34. Deletion of mTORC1 Activity in CD4+ T Cells Is Associated with Lung Fibrosis and Increased γδ T Cells.
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Christine L Vigeland, Samuel L Collins, Yee Chan-Li, Andrew H Hughes, Min-Hee Oh, Jonathan D Powell, and Maureen R Horton
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Medicine ,Science - Abstract
Pulmonary fibrosis is a devastating, incurable disease in which chronic inflammation and dysregulated, excessive wound healing lead to progressive fibrosis, lung dysfunction, and ultimately death. Prior studies have implicated the cytokine IL-17A and Th17 cells in promoting the development of fibrosis. We hypothesized that loss of Th17 cells via CD4-specific deletion of mTORC1 activity would abrogate the development of bleomycin-induced pulmonary fibrosis. However, in actuality loss of Th17 cells led to increased mortality and fibrosis in response to bleomycin. We found that in the absence of Th17 cells, there was continued production of IL-17A by γδ T cells. These IL-17A+ γδ T cells were associated with increased lung neutrophils and M2 macrophages, accelerated development of fibrosis, and increased mortality. These data elucidate the critical role of IL-17A+ γδ T cells in promoting chronic inflammation and fibrosis, and reveal a novel therapeutic target for treatment of pulmonary fibrosis.
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- 2016
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35. Maternally provided LSD1/KDM1A enables the maternal-to-zygotic transition and prevents defects that manifest postnatally
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Jadiel A Wasson, Ashley K Simon, Dexter A Myrick, Gernot Wolf, Shawn Driscoll, Samuel L Pfaff, Todd S Macfarlan, and David J Katz
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epigenetics ,MZT ,KDM1a ,maternal effect ,LSD1 ,genomic imprinting ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Somatic cell nuclear transfer has established that the oocyte contains maternal factors with epigenetic reprogramming capacity. Yet the identity and function of these maternal factors during the gamete to embryo transition remains poorly understood. In C. elegans, LSD1/KDM1A enables this transition by removing H3K4me2 and preventing the transgenerational inheritance of transcription patterns. Here we show that loss of maternal LSD1/KDM1A in mice results in embryonic arrest at the 1-2 cell stage, with arrested embryos failing to undergo the maternal-to-zygotic transition. This suggests that LSD1/KDM1A maternal reprogramming is conserved. Moreover, partial loss of maternal LSD1/KDM1A results in striking phenotypes weeks after fertilization; including perinatal lethality and abnormal behavior in surviving adults. These maternal effect hypomorphic phenotypes are associated with alterations in DNA methylation and expression at imprinted genes. These results establish a novel mammalian paradigm where defects in early epigenetic reprogramming can lead to defects that manifest later in development.
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- 2016
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36. Q Fever Surveillance in Ruminants, Thailand, 2012
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Samuel L. Yingst, Pattarin Opaschaitat, Reka Kanitpun, Suree Thammasart, Monaya Ekgatat, Vimol Jirathanawat, and Preecha Wongwicharn
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Q fever ,Coxiella burnetii ,bacteria ,ruminants ,surveillance ,PCR ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Published
- 2013
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37. Turbid Peritoneal Fluid
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Samuel L. Burleson, MD and Henry E. Wang, MD, MS
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peritoneal fluid ,peritonitis ,diagnostic procedures ,Medicine ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
CASE A 58-year-old female with a past medical history of hepatitis C virus-induced cirrhosis presented to the emergency department with three days of increasing abdominal pain, chills, and nausea and vomiting. Abdominal physical examination revealed gross ascites with fluid wave. Diagnostic paracentesis resulted in the aspiration of approximately 60mL of white turbid peritoneal fluid (Figure).
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- 2016
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38. Endemic, Notifiable Bioterrorism-Related Diseases, United States, 1992–1999
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Man-huei Chang, M. Kathleen Glynn, and Samuel L. Groseclose
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bioterrorism ,incidence ,research ,United States ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Little information is available in the United States regarding the incidence and distribution of diseases caused by critical microbiologic agents with the potential for use in acts of terrorism. We describe disease-specific, demographic, geographic, and seasonal distribution of selected bioterrorism-related conditions (anthrax, botulism, brucellosis, cholera, plague, tularemia, and viral encephalitides) reported to the National Notifiable Diseases Surveillance System in 1992–1999. Tularemia and brucellosis were the most frequently reported diseases. Anthrax, plague, western equine encephalitis, and eastern equine encephalitis were rare. Higher incidence rates for cholera and plague were noted in the western United States and for tularemia in the central United States. Overall, the incidence of conditions caused by these critical agents in the United States is low. Individual case reports should be considered sentinel events. For potential bioterrorism-related conditions that are endemic and have low incidence, the use of nontraditional surveillance methods and complementary data sources may enhance our ability to rapidly detect changes in disease incidence.
- Published
- 2003
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39. No sex-biased dispersal in a primate with an uncommon social system—cooperative polyandry
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Samuel L. Díaz-Muñoz and Ângela M. Ribeiro
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Local resource enhancement ,Local mate competition ,Inbreeding avoidance ,Sex-biased dispersal ,Population structure ,Kin cooperation ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
An influential hypothesis proposed by Greenwood (1980) suggests that different mating systems result in female and male-biased dispersal, respectively, in birds and mammals. However, other aspects of social structure and behavior can also shape sex-biased dispersal. Although sex-specific patterns of kin cooperation are expected to affect the benefits of philopatry and dispersal patterns, empirical evidence is scarce. Unlike many mammals, Saguinus geoffroyi (Geoffroy’s tamarin) has a breeding system in which typically multiple males mate with a single breeding female. Males typically form cooperative reproductive partnerships between relatives, whereas females generally compete for reproductive opportunities. This system of cooperative polyandry is predicted to result in female-biased dispersal, providing an opportunity to test the current hypotheses of sex-biased dispersal. Here we test for evidence of sex-biased dispersal in S. geoffroyi using demographic and genetic data from three populations. We find no sex bias in natal dispersal, contrary to the prediction based on the mating patterns. This pattern was consistent after controlling for the effects of historical population structure. Limited breeding opportunities within social groups likely drive both males and females to disperse, suggesting that dispersal is intimately related to the social context. The integration of genetic and field data revealed that tamarins are another exception to the presumed pattern of male-biased dispersal in mammals. A shift in focus from mating systems to social behavior, which plays a role in most all processes expected to influence sex-bias in dispersal, will be a fruitful target for research both within species and across taxa.
- Published
- 2014
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40. Healthcare resource utilization for recurrent Clostridium difficile infection in a large university hospital in Houston, Texas.
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Samuel L Aitken, Tiby B Joseph, Dhara N Shah, Todd M Lasco, Hannah R Palmer, Herbert L DuPont, Yang Xie, and Kevin W Garey
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Medicine ,Science - Abstract
BackgroundThere are limited data examining healthcare resource utilization in patients with recurrent Clostridium difficile infection (CDI).MethodsPatients with CDI at a tertiary-care hospital in Houston, TX, were prospectively enrolled into an observational cohort study. Recurrence was assessed via follow-up phone calls. Patients with one or more recurrence were included in this study. The location at which healthcare was obtained by patients with recurrent CDI was identified along with hospital length of stay. CDI-attributable readmissions, defined as a positive toxin test within 48 hours of admission and a primary CDI diagnosis, were also assessed.Results372 primary cases of CDI were identified of whom 64 (17.2%) experienced at least one CDI recurrence. Twelve of 64 patients experienced 18 further episodes of CDI recurrence. Of these 64 patients, 33 (50.8%) patients with recurrent CDI were readmitted of which 6 (18.2%) required ICU care, 29 (45.3%) had outpatient care only, and 2 (3.1%) had an ED visit. Nineteen (55.9%) readmissions were defined as CDI-attributable. For patients with CDI-attributable readmission, the average length of stay was 6 ± 6 days.ConclusionRecurrent CDI leads to significant healthcare resource utilization. Methods of reducing the burden of recurrent CDI should be further studied.
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- 2014
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41. Egr3 induces a Th17 response by promoting the development of γδ T cells.
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Rose M Parkinson, Samuel L Collins, Maureen R Horton, and Jonathan D Powell
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Medicine ,Science - Abstract
The transcription factor Early Growth Response 3 (Egr3) has been shown to play an important role in negatively regulating T cell activation and promoting T cell anergy in Th1 cells. However, its role in regulating other T helper subsets has yet to be described. We sought to determine the role of Egr3 in a Th17 response using transgenic mice that overexpress Egr3 in T cells (Egr3 TG). Splenocytes from Egr3 TG mice demonstrated more robust generation of Th17 cells even under non-Th17 skewing conditions. We found that while Egr3 TG T cells were not intrinsically more likely to become Th17 cells, the environment encountered by these cells was more conducive to Th17 development. Further analysis revealed a considerable increase in the number of γδ T cells in both the peripheral lymphoid organs and mucosal tissues of Egr3 TG mice, a cell type which normally accounts for only a small fraction of peripheral lymphocytes. Consistent with this marked increase in peripheral γδ T cells, thymocytes from Egr3 TG mice also appear biased toward γδ T cell development. Coculture of these Egr3-induced γδ T cells with wildtype CD4+ T cells increases Th17 differentiation, and Egr3 TG mice are more susceptible to bleomycin-induced lung inflammation. Overall our findings strengthen the role for Egr3 in promoting γδ T cell development and show that Egr3-induced γδ T cells are both functional and capable of altering the adaptive immune response in a Th17-biased manner. Our data also demonstrates that the role played by Egr3 in T cell activation and differentiation is more complex than previously thought.
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- 2014
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42. Qinghai-like H5N1 from Domestic Cats, Northern Iraq
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Samuel L. Yingst, Magdi D. Saad, and Stephen A. Felt
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Avian Influenza ,H5N1 ,Cat ,Goose ,Human ,Zoonoses ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Published
- 2006
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43. Towards clinical molecular diagnosis of inherited cardiac conditions: a comparison of bench-top genome DNA sequencers.
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Xinzhong Li, Andrew J Buckton, Samuel L Wilkinson, Shibu John, Roddy Walsh, Tomas Novotny, Iveta Valaskova, Manu Gupta, Laurence Game, Paul J R Barton, Stuart A Cook, and James S Ware
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Medicine ,Science - Abstract
BACKGROUND:Molecular genetic testing is recommended for diagnosis of inherited cardiac disease, to guide prognosis and treatment, but access is often limited by cost and availability. Recently introduced high-throughput bench-top DNA sequencing platforms have the potential to overcome these limitations. METHODOLOGY/PRINCIPAL FINDINGS:We evaluated two next-generation sequencing (NGS) platforms for molecular diagnostics. The protein-coding regions of six genes associated with inherited arrhythmia syndromes were amplified from 15 human samples using parallelised multiplex PCR (Access Array, Fluidigm), and sequenced on the MiSeq (Illumina) and Ion Torrent PGM (Life Technologies). Overall, 97.9% of the target was sequenced adequately for variant calling on the MiSeq, and 96.8% on the Ion Torrent PGM. Regions missed tended to be of high GC-content, and most were problematic for both platforms. Variant calling was assessed using 107 variants detected using Sanger sequencing: within adequately sequenced regions, variant calling on both platforms was highly accurate (Sensitivity: MiSeq 100%, PGM 99.1%. Positive predictive value: MiSeq 95.9%, PGM 95.5%). At the time of the study the Ion Torrent PGM had a lower capital cost and individual runs were cheaper and faster. The MiSeq had a higher capacity (requiring fewer runs), with reduced hands-on time and simpler laboratory workflows. Both provide significant cost and time savings over conventional methods, even allowing for adjunct Sanger sequencing to validate findings and sequence exons missed by NGS. CONCLUSIONS/SIGNIFICANCE:MiSeq and Ion Torrent PGM both provide accurate variant detection as part of a PCR-based molecular diagnostic workflow, and provide alternative platforms for molecular diagnosis of inherited cardiac conditions. Though there were performance differences at this throughput, platforms differed primarily in terms of cost, scalability, protocol stability and ease of use. Compared with current molecular genetic diagnostic tests for inherited cardiac arrhythmias, these NGS approaches are faster, less expensive, and yet more comprehensive.
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- 2013
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44. Fibroblast Migration Is Regulated by Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS) Protein.
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Laura E Ott, Eui Jae Sung, Adam T Melvin, Mary K Sheats, Jason M Haugh, Kenneth B Adler, and Samuel L Jones
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Medicine ,Science - Abstract
Myristoylated alanine-rich C-kinase substrate (MARCKS) is a ubiquitously expressed substrate of protein kinase C (PKC) that is involved in reorganization of the actin cytoskeleton. We hypothesized that MARCKS is involved in regulation of fibroblast migration and addressed this hypothesis by utilizing a unique reagent developed in this laboratory, the MANS peptide. The MANS peptide is a myristoylated cell permeable peptide corresponding to the first 24-amino acids of MARCKS that inhibits MARCKS function. Treatment of NIH-3T3 fibroblasts with the MANS peptide attenuated cell migration in scratch wounding assays, while a myristoylated, missense control peptide (RNS) had no effect. Neither MANS nor RNS peptide treatment altered NIH-3T3 cell proliferation within the parameters of the scratch assay. MANS peptide treatment also resulted in inhibited NIH-3T3 chemotaxis towards the chemoattractant platelet-derived growth factor-BB (PDGF-BB), with no effect observed with RNS treatment. Live cell imaging of PDGF-BB induced chemotaxis demonstrated that MANS peptide treatment resulted in weak chemotactic fidelity compared to RNS treated cells. MANS and RNS peptides did not affect PDGF-BB induced phosphorylation of MARCKS or phosphoinositide 3-kinase (PI3K) signaling, as measured by Akt phosphorylation. Further, no difference in cell migration was observed in NIH-3T3 fibroblasts that were transfected with MARCKS siRNAs with or without MANS peptide treatment. Genetic structure-function analysis revealed that MANS peptide-mediated attenuation of NIH-3T3 cell migration does not require the presence of the myristic acid moiety on the amino-terminus. Expression of either MANS or unmyristoylated MANS (UMANS) C-terminal EGFP fusion proteins resulted in similar levels of attenuated cell migration as observed with MANS peptide treatment. These data demonstrate that MARCKS regulates cell migration and suggests that MARCKS-mediated regulation of fibroblast migration involves the MARCKS amino-terminus. Further, this data demonstrates that MANS peptide treatment inhibits MARCKS function during fibroblast migration and that MANS mediated inhibition occurs independent of myristoylation.
- Published
- 2013
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45. Personal and household hygiene, environmental contamination, and health in undergraduate residence halls in New York City, 2011.
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Benjamin A Miko, Bevin Cohen, Katharine Haxall, Laurie Conway, Nicole Kelly, Dianne Stare, Christina Tropiano, Allan Gilman, Samuel L Seward, and Elaine Larson
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Medicine ,Science - Abstract
While several studies have documented the importance of hand washing in the university setting, the added role of environmental hygiene remains poorly understood. The purpose of this study was to characterize the personal and environmental hygiene habits of college students, define the determinants of hygiene in this population, and assess the relationship between reported hygiene behaviors, environmental contamination, and health status.501 undergraduate students completed a previously validated survey assessing baseline demographics, hygiene habits, determinants of hygiene, and health status. Sixty survey respondents had microbiological samples taken from eight standardized surfaces in their dormitory environment. Bacterial contamination was assessed using standard quantitative bacterial culture techniques. Additional culturing for coagulase-positive Staphylococcus and coliforms was performed using selective agar.While the vast majority of study participants (n = 461, 92%) believed that hand washing was important for infection prevention, there was a large amount of variation in reported personal hygiene practices. More women than men reported consistent hand washing before preparing food (p = .002) and after using the toilet (p = .001). Environmental hygiene showed similar variability although 73.3% (n = 367) of subjects reported dormitory cleaning at least once per month. Contamination of certain surfaces was common, with at least one third of all bookshelves, desks, refrigerator handles, toilet handles, and bathroom door handles positive for >10 CFU of bacteria per 4 cm(2) area. Coagulase-positive Staphylococcus was detected in three participants' rooms (5%) and coliforms were present in six students' rooms (10%). Surface contamination with any bacteria did not vary by frequency of cleaning or frequency of illness (p>.05).Our results suggest that surface contamination, while prevalent, is unrelated to reported hygiene or health in the university setting. Further research into environmental reservoirs of infectious diseases may delineate whether surface decontamination is an effective target of hygiene interventions in this population.
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- 2013
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46. Intraventricularly Injected Olig2-NSCs Attenuate Established Relapsing–Remitting EAE in Mice
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Falak Sher, Sandra Amor, Wouter Gerritsen, David Baker, Samuel L. Jackson, Erik Boddeke, and Sjef Copray
- Subjects
Medicine - Abstract
In multiple sclerosis (MS), a chronic inflammatory relapsing demyelinating disease, failure to control or repair damage leads to progressive neurological dysfunction and neurodegeneration. Implantation of neural stem cells (NSCs) has been shown to promote repair and functional recovery in the acute experimental autoimmune encephalomyelitis (EAE) animal model for MS; the major therapeutic mechanism of these NSCs appeared to be immune regulation. In the present study, we examined the efficacy of intraventricularly injected NSCs in chronic relapsing experimental autoimmune encephalomyelitis (CREAE), the animal disease model that is widely accepted to mimic most closely recurrent inflammatory demyelination lesions as observed in relapsing–remitting MS. In addition, we assessed whether priming these NSCs to become oligodendrocyte precursor cells (OPCs) by transient overexpression of Olig2 would further promote functional recovery, for example, by contributing to actual remyelination. Upon injection at the onset of the acute phase or the relapse phase of CREAE, NSCs as well as Olig2-NSCs directly migrated toward active lesions in the spinal cord as visualized by in vivo bioluminescence and biofluorescence imaging, and once in the spinal cord, the majority of Olig2-NSCs, in contrast to NSCs, differentiated into OPCs. The survival of Olig2-NSCs was significantly higher than that of injected control NSCs, which remained undifferentiated. Nevertheless, both Olig2-NSCs and NSC significantly reduced the clinical signs of acute and relapsing disease and, in case of Olig2-NSCs, even completely abrogated relapsing disease when administered early after onset of acute disease. We provide the first evidence that NSCs and in particular NSC-derived OPCs (Olig2-NSCs) ameliorate established chronic relapsing EAE in mice. Our experimental data in established neurological disease in mice indicate that such therapy may be effective in relapsing–remitting MS preventing chronic progressive disease.
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- 2012
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47. Age-dependent changes in the sphingolipid composition of mouse CD4+ T cell membranes and immune synapses implicate glucosylceramides in age-related T cell dysfunction.
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Alberto Molano, Zhaofeng Huang, Melissa G Marko, Angelo Azzi, Dayong Wu, Elaine Wang, Samuel L Kelly, Alfred H Merrill, Stephen C Bunnell, and Simin Nikbin Meydani
- Subjects
Medicine ,Science - Abstract
To determine whether changes in sphingolipid composition are associated with age-related immune dysfunction, we analyzed the core sphingolipidome (i.e., all of the metabolites through the first headgroup additions) of young and aged CD4(+) T cells. Since sphingolipids influence the biophysical properties of membranes, we evaluated the compositions of immune synapse (IS) and non-IS fractions prepared by magnetic immuno-isolation. Broadly, increased amounts of sphingomyelins, dihydrosphingomyelins and ceramides were found in aged CD4(+) T cells. After normalizing for total sphingolipid content, a statistically significant decrease in the molar fraction of glucosylceramides was evident in both the non-IS and IS fractions of aged T cells. This change was balanced by less dramatic increases in the molar fractions of sphingomyelins and dihydrosphingomyelins in aged CD4(+) T cells. In vitro, the direct or enzymatic enhancement of ceramide levels decreased CD4(+) T cell proliferation without regard for the age of the responding T cells. In contrast, the in vitro inhibition of glucosylceramidase preferentially increased the proliferation of aged CD4(+) T cells. These results suggest that reductions in glucosylceramide abundance contribute to age-related impairments in CD4(+) T cell function.
- Published
- 2012
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48. Pulmonary vaccination as a novel treatment for lung fibrosis.
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Samuel L Collins, Yee Chan-Li, Robert W Hallowell, Jonathan D Powell, and Maureen R Horton
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Medicine ,Science - Abstract
Pulmonary fibrosis is an untreatable, uniformly fatal disease of unclear etiology that is the result of unremitting chronic inflammation. Recent studies have implicated bone marrow derived fibrocytes and M2 macrophages as playing key roles in propagating fibrosis. While the disease process is characterized by the accumulation of lymphocytes in the lung parenchyma and alveolar space, their role remains unclear. In this report we definitively demonstrate the ability of T cells to regulate lung inflammation leading to fibrosis. Specifically we demonstrate the ability of intranasal vaccinia vaccination to inhibit M2 macrophage generation and fibrocyte recruitment and hence the accumulation of collagen and death due to pulmonary failure. Mechanistically, we demonstrate the ability of lung Th1 cells to prevent fibrosis as vaccinia failed to prevent disease in Rag-/- mice or in mice in which the T cells lacked IFN-γ. Furthermore, vaccination 3 months prior to the initiation of fibrosis was able to mitigate the disease. Our findings clearly demonstrate the role of T cells in regulating pulmonary fibrosis as well as suggest that vaccinia-induced immunotherapy in the lung may prove to be a novel treatment approach to this otherwise fatal disease.
- Published
- 2012
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49. Bioinformatic analysis and post-translational modification crosstalk prediction of lysine acetylation.
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Zhike Lu, Zhongyi Cheng, Yingming Zhao, and Samuel L Volchenboum
- Subjects
Medicine ,Science - Abstract
Recent proteomics studies suggest high abundance and a much wider role for lysine acetylation (K-Ac) in cellular functions. Nevertheless, cross influence between K-Ac and other post-translational modifications (PTMs) has not been carefully examined. Here, we used a variety of bioinformatics tools to analyze several available K-Ac datasets. Using gene ontology databases, we demonstrate that K-Ac sites are found in all cellular compartments. KEGG analysis indicates that the K-Ac sites are found on proteins responsible for a diverse and wide array of vital cellular functions. Domain structure prediction shows that K-Ac sites are found throughout a wide variety of protein domains, including those in heat shock proteins and those involved in cell cycle functions and DNA repair. Secondary structure prediction proves that K-Ac sites are preferentially found in ordered structures such as alpha helices and beta sheets. Finally, by mutating K-Ac sites in silico and predicting the effect on nearby phosphorylation sites, we demonstrate that the majority of lysine acetylation sites have the potential to impact protein phosphorylation, methylation, and ubiquitination status. Our work validates earlier smaller-scale studies on the acetylome and demonstrates the importance of PTM crosstalk for regulation of cellular function.
- Published
- 2011
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50. Down-regulation of DNA mismatch repair enhances initiation and growth of neuroblastoma and brain tumour multicellular spheroids.
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Samuel L Collins, Rodolphe Hervé, C W Keevil, Jeremy P Blaydes, and Jeremy S Webb
- Subjects
Medicine ,Science - Abstract
Multicellular tumour spheroid (MCTS) cultures are excellent model systems for simulating the development and microenvironmental conditions of in vivo tumour growth. Many documented cell lines can generate differentiated MCTS when cultured in suspension or in a non-adhesive environment. While physiological and biochemical properties of MCTS have been extensively characterized, insight into the events and conditions responsible for initiation of these structures is lacking. MCTS are formed by only a small subpopulation of cells during surface-associated growth but the processes responsible for this differentiation are poorly understood and have not been previously studied experimentally. Analysis of gene expression within spheroids has provided clues but to date it is not known if the observed differences are a cause or consequence of MCTS growth. One mechanism linked to tumourigenesis in a number of cancers is genetic instability arising from impaired DNA mismatch repair (MMR). This study aimed to determine the role of MMR in MCTS initiation and development. Using surface-associated N2a and CHLA-02-ATRT culture systems we have investigated the impact of impaired MMR on MCTS growth. Analysis of the DNA MMR genes MLH1 and PMS2 revealed both to be significantly down-regulated at the mRNA level compared with non-spheroid-forming cells. By using small interfering RNA (siRNA) against these genes we show that silencing of MLH1 and PMS2 enhances both MCTS initiation and subsequent expansion. This effect was prolonged over several passages following siRNA transfection. Down-regulation of DNA MMR can contribute to tumour initiation and progression in N2a and CHLA-02-ATRT MCTS models. Studies of surface-associated MCTS differentiation may have broader applications in studying events in the initiation of cancer foci.
- Published
- 2011
- Full Text
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