106 research outputs found
CD8+ Trms against malaria liver-stage: prospects and challenges
Attenuated sporozoites provide a valuable model for exploring protective immunity against the malarial liver stage, guiding the design of highly efficient vaccines to prevent malaria infection. Liver tissue-resident CD8+ T cells (CD8+ Trm cells) are considered the host front-line defense against malaria and are crucial to developing prime-trap/target strategies for pre-erythrocytic stage vaccine immunization. However, the spatiotemporal regulatory mechanism of the generation of liver CD8+ Trm cells and their responses to sporozoite challenge, as well as the protective antigens they recognize remain largely unknown. Here, we discuss the knowledge gap regarding liver CD8+ Trm cell formation and the potential strategies to identify predominant protective antigens expressed in the exoerythrocytic stage, which is essential for high-efficacy malaria subunit pre-erythrocytic vaccine designation
Propagation and Pitfalls: Reasoning-based Assessment of Knowledge Editing through Counterfactual Tasks
Current approaches of knowledge editing struggle to effectively propagate
updates to interconnected facts. In this work, we delve into the barriers that
hinder the appropriate propagation of updated knowledge within these models for
accurate reasoning. To support our analysis, we introduce a novel
reasoning-based benchmark -- ReCoE (Reasoning-based Counterfactual Editing
dataset) -- which covers six common reasoning schemes in real world. We conduct
a thorough analysis of existing knowledge editing techniques, including input
augmentation, finetuning, and locate-and-edit. We found that all model editing
methods show notably low performance on this dataset, especially in certain
reasoning schemes. Our analysis over the chain-of-thought generation of edited
models further uncover key reasons behind the inadequacy of existing knowledge
editing methods from a reasoning standpoint, involving aspects on fact-wise
editing, fact recall ability, and coherence in generation. We will make our
benchmark publicly available.Comment: 22 pages, 14 figures, 5 table
Spatial Linear Mixed Effects Modelling for OCT Images: SLME Model.
Much recent research focuses on how to make disease detection more accurate as well as "slimmer", i.e., allowing analysis with smaller datasets. Explanatory models are a hot research topic because they explain how the data are generated. We propose a spatial explanatory modelling approach that combines Optical Coherence Tomography (OCT) retinal imaging data with clinical information. Our model consists of a spatial linear mixed effects inference framework, which innovatively models the spatial topography of key information via mixed effects and spatial error structures, thus effectively modelling the shape of the thickness map. We show that our spatial linear mixed effects (SLME) model outperforms traditional analysis-of-variance approaches in the analysis of Heidelberg OCT retinal thickness data from a prospective observational study, involving 300 participants with diabetes and 50 age-matched controls. Our SLME model has a higher power for detecting the difference between disease groups, and it shows where the shape of retinal thickness profiles differs between the eyes of participants with diabetes and the eyes of healthy controls. In simulated data, the SLME model demonstrates how incorporating spatial correlations can increase the accuracy of the statistical inferences. This model is crucial in the understanding of the progression of retinal thickness changes in diabetic maculopathy to aid clinicians for early planning of effective treatment. It can be extended to disease monitoring and prognosis in other diseases and with other imaging technologies
Improving Long-Term Adherence to Monitoring/Treatment in Underserved Asian Americans with Chronic Hepatitis B (CHB) through a Multicomponent Culturally Tailored Intervention: A Randomized Controlled Trial
Background: Although Asian Americans make up 6% of the U.S. population, they account for 58% of Americans with chronic hepatitis B (CHB). Yet, adherence to monitoring and antiviral treatment guidelines among Asian American CHB patients remains suboptimal. Methods: The purpose of this study was to evaluate the efficacy of a multicomponent intervention on adherence to CHB monitoring among Asian Americans with CHB. The intervention components included virtual patient education, patient navigation, and mobile health reminders delivered by bilingual community health educators. Chi-square test and t -test were used to compare demographic characteristics and two CHB measures: CHB clinical follow-up and CHB laboratory monitoring by the time of the 12-month follow-up assessment. A generalized linear mixed-effects model (GLMM) was fitted to assess the effectiveness of the intervention. Results: The study sample consisted of 358 Chinese and Vietnamese Americans living with CHB, including 181 in the intervention group and 177 in the control group. The intervention group had a significantly higher rate of CHB clinical follow- up (86.2%) and CHB laboratory monitoring (79.0%) than did the control group (54.2% and 45.2%, respectively). Results of the GLMM showed significant intervention effects on CHB clinical follow-up (odds ratio = 7.35, 95% confidence interval = 4.06–13.33) and CHB laboratory monitoring (odds ratio = 6.60, 95% confidence interval = 3.77–11.56) at the 12-month follow-up assessment. Conclusion: The multicomponent intervention was effective in improving adherence to CHB monitoring among Asian Americans. Additional implementation research is needed to better understand and apply effective interventions to other underserved populations
Factors Associated with Hepatitis B Medication Adherence and Persistence among Underserved Chinese and Vietnamese Americans
Background: Hepatitis B virus (HBV) infection disproportionately affects Asian Amer- icans in the United States, while this population faces low adherence to HBV treatment. Using the information–motivation–behavioral skills model (IMB), the study aims to examine medication adherence and persistence among Chinese and Vietnamese people with HBV. Methodology: Study participants were recruited between March 2019 and March 2020 and were enrolled through multiple recruitment approaches in the Greater Philadelphia Area and New York City. The study is an assess- ment of the baseline data on medication adherence, HBV-related knowledge, motivation of HBV med- ication treatment, self-efficacy about HBV medication treatment, and socioeconomic status. Results: Among 165 participants, 77.6% were Chinese and 22.4% were Vietnamese Americans. HBV-related knowledge/information, motivation, and self-efficacy were all positively associated with having medium/high medication adherence. Multilevel mixed-effects generalized linear regression revealed that living more than 10 years in the U.S. (OR = 4.24; p = 0.028) and greater information–knowledge about HBV (OR = 1.46; p = 0.004) were statistically associated with higher odds of medium/high medication adherence. Moreover, greater HBV-related knowledge/information ( OR = 1.49; p = 0.023) and greater motivation towards HBV treatment adherence (OR = 1.10; p = 0.036) were both associated with a higher likelihood of medication persistence. Conclusion: Our findings provided significant im- plications in designing behavioral interventions focused on self-efficacy, information, and motivation to promote better medication adherence among Asian Americans living with HBV
Early transient suppression of immune checkpoint proteins T-cell immunoglobulin mucin-3 and programmed cell death-1 in peripheral blood lymphocytes after blastocyst transfer is associated with successful implantation
Objective
To compare the changing peripheral levels of immune checkpoint proteins T-cell immunoglobulin mucin-3 (Tim-3)/galectin-9 (Gal-9), and programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) over a 9-day period after blastocyst transfer between women who did and did not conceive.
Design
Prospective observational study.
Setting
University teaching hospital.
Patients(s)
Fifty-one infertile women undergoing day-5 blastocyst transfer.
Intervention(s)
Serial blood samples obtained on the day of embryo transfer (ET), and 3, 6, and 9 days afterward for measurement of membranous Tim-3 and PD-1 expression on various peripheral lymphocytes by flow cytometry, and serum concentrations of ligands Gal-9 and PD-L1 by ELISA.
Main Outcome Measure(s)
Membranous Tim-3 and PD-1 expression on lymphocytes and serum Gal-9 and PD-L1 concentrations and comparison of results between pregnant and nonpregnant women.
Result(s)
In women who conceived, the measurements exhibited three different types of response: [1] a transient and statistically significant reduction of Tim-3+NK-like T cells, Tim-3+/PD-1+CD8+ T cells, and Tim-3+/PD-1+CD4+ T cells that returned back to baseline level 9 days after ET; [2] a reduction followed by steady increase to above baseline level on day 9 (Tim-3+CD56dimNK cells); [3] a steady increase in expression after ET to reach a level statistically significantly higher than that of the baseline by day 9 (Tim-3+CD56brightNK cells). Women who did not conceive showed no statistically significant fluctuation in any of the parameters measured across the four time pointswith exception of increased Tim-3 expression on NK cells on day 9.
Conclusion(s)
Successful blastocyst implantation is associated with a reduction of Tim-3 and PD-1 expression in peripheral lymphocytes on days 3 and 6 that is no longer apparent on day 9
Development and external validation of a mixed-effects deep learning model to diagnose COVID-19 from CT imaging
BackgroundThe automatic analysis of medical images has the potential improve diagnostic accuracy while reducing the strain on clinicians. Current methods analyzing 3D-like imaging data, such as computerized tomography imaging, often treat each image slice as individual slices. This may not be able to appropriately model the relationship between slices.MethodsOur proposed method utilizes a mixed-effects model within the deep learning framework to model the relationship between slices. We externally validated this method on a data set taken from a different country and compared our results against other proposed methods. We evaluated the discrimination, calibration, and clinical usefulness of our model using a range of measures. Finally, we carried out a sensitivity analysis to demonstrate our methods robustness to noise and missing data.ResultsIn the external geographic validation set our model showed excellent performance with an AUROC of 0.930 (95%CI: 0.914, 0.947), with a sensitivity and specificity, PPV, and NPV of 0.778 (0.720, 0.828), 0.882 (0.853, 0.908), 0.744 (0.686, 0.797), and 0.900 (0.872, 0.924) at the 0.5 probability cut-off point. Our model also maintained good calibration in the external validation dataset, while other methods showed poor calibration.ConclusionDeep learning can reduce stress on healthcare systems by automatically screening CT imaging for COVID-19. Our method showed improved generalizability in external validation compared to previous published methods. However, deep learning models must be robustly assessed using various performance measures and externally validated in each setting. In addition, best practice guidelines for developing and reporting predictive models are vital for the safe adoption of such models
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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