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"Yang, Eun Sung"
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Accelerating problem-solving capacities of sub-national public health professionals: an evaluation of a digital immunization training intervention
by
Dailey, Cody Aaron
,
Yang, Sung-Eun
,
Galen, Robert S.
in
Capacity-building
,
Collaboration
,
Design
2022
Background
This article reports an evaluation of the
Immunization Training Challenge Hackathons
(ITCH)
,
invented by The Geneva Learning Foundation (TGLF) for national and sub-national immunization staff who strive to develop the knowledge and capacity of others to improve immunization program performance. ITCH, a fully-digital program focused on networked collaborative problem-solving between peers, provided an “opt-in” activity for learners in the Teach to Reach (T2R) Accelerator Program designed to improve training effectiveness in the immunization sphere.
Methods
Conducted by a team from the University of Georgia, this mixed method evaluation consisted of thematic analysis of recorded sessions and open-ended comments; and statistical analyses of application and follow-up survey data. The evaluation focused on what was learned and how ITCH participants implemented what they learned
.
Key stakeholder interviews provided supplemental data about program intent and results. ITCH consisted of 17 30-min sessions held in 2020, in English and French, with 581 participating at least once out of 1,454 enrolled in the overall program. Challenge owners and respondents came from 15 African and Asian countries and spanned different roles with differing scope.
Results
Over 85% [
n
= 154] of survey respondents [
n
= 181, a 31% response rate] indicated they were able to implement what they learned from the ITCH sessions. A majority [
n
= 139, 76.7%] reported finding the sessions useful. Issues with poor connectivity and the timing of the live meetings impeded some in their ability to participate, a problem compounded by consequences of the pandemic. The ITCH process constituted of learning or coming to consciousness simultaneously of four types of learning — participants realizing how much they could learn from each other (peer learning), experiencing the power of defying distance to solve problems together (remote learning), and feeling a growing sense of belonging to a community (social learning), emergent across country borders and health system levels (networked learning).
Conclusions
Based on evaluation findings, it was concluded that ITCH demonstrated an effective scalable, informal, non-didactic, experience-led, fast-paced, peer learning design. A focus on community engagement and developing brokering skills was recommended.
Journal Article
Fine-Needle Aspiration Versus Frozen Section in the Evaluation of Malignant Thyroid Nodules in Patients With the Diagnosis of Suspicious for Malignancy or Malignancy by Fine-Needle Aspiration
2017
- The Bethesda System for Reporting Thyroid Cytopathology recommends against the use of intraoperative frozen section (FS) during lobectomy of a thyroid nodule with a fine-needle aspiration (FNA) diagnosis of malignant. Bethesda recommendations for FS in the FNA category of suspicious for malignancy (SFM) is less well-defined. In some institutions in China, FS examination is performed during lobectomy even for FNA-proven malignant cases.
- -To compare the efficacy of FNA versus FS in the evaluation of malignant thyroid lesions.
- A 3-year retrospective analysis from a single institution was performed on cases with an FNA diagnosis of SFM or malignant with subsequent FS examination during thyroidectomy. The results of FNA and FS findings were compared to the final thyroidectomy pathology.
- -A total of 5832 thyroidectomy procedures were performed: 1265 cases had FNA and FS results available. Fine-needle aspiration gave a diagnosis of SFM to 306 cases and a diagnosis of malignant to 821 cases. Of the SFM cases, 10.5% (32 of 306) had benign/indeterminate, 4.6% (14 of 306) suspicious, and 84.9% (260 of 306) malignant FS results. Final pathology showed 56.3% (18 of 32), 64.3% (9 of 14), and 100% (260 of 260) malignancy rates, respectively. For the malignant FNA group, 10.0% (82 of 821) had benign/indeterminate, 4.4% (36 of 821) suspicious, and 85.6% (703 of 821) malignant FS results. The final pathology showed 96.4% (79 of 82), 97.2% (35 of 36), and 99.9% (702 of 703) malignancy rates, respectively.
- Frozen section should not be performed for the malignant FNA category because FS evaluation may result in 10% falsely negative findings. Performing FS for SFM may be better justified; however, more than half of FS cases read as benign in this category had malignant final pathology. Therefore, caution should be taken for FS results even in the SFM group.
Journal Article
Comparison of Anti-Bacterial Efficacy between Passive Ultrasonic Irrigation and 980 nm-GaAlAs Laser Application in Two Root Types
2021
Background and Objectives: The purpose of the present study was to investigate the anti-bacterial efficacy of passive ultrasonic irrigation (PUI) and a 980-nm-gallium-aluminum-arsenide (GaAlAs) laser using a real-time DNA-based quantitative polymerase chain reaction (qPCR) assay and scanning electron microscopy (SEM). Materials and Methods: Eighty-six extracted single- and double-rooted human teeth were used in the experiment. The following four experimental groups were evaluated, as well as a control group: group 1: single root + PUI (n = 20); group 2: single root + laser application (n = 20); group 3: double roots + PUI (n = 20); group 4: double roots + laser application (n =20); control group (n = 6): 3 single roots, 3 double roots. The qPCR assay was performed in three stages to evaluate the efficacy of the adjunctive method against Enterococcus faecalis. SEM analysis was also used to examine the microstructure of root canal surfaces. The data were statistically analyzed using the Friedman test and the Kruskal–Wallis test with Bonferroni adjustment. Results: The decrease in the DNA levels from S1 (before preparation) to S2 (just after preparation) was highly significant in all groups, and decreases in DNA levels from S2 to S3 (after incubation for 1 week) were found in all experimental groups except group 1. An inter-group analysis showed that PUI was significantly more effective in terms of antibacterial efficacy than GaAlAs laser irradiation in single root (p < 0.05). However, in double roots, experimental groups did not show significantly lower DNA levels than the control group (p > 0.05). SEM images showed that cleaning of the root canal surface and reduction of dentin debris were achieved only in single-rooted teeth when using PUI application. Conclusions: Two adjunctive methods were effective in reducing E. faecalis in single rooted tooth.
Journal Article
Analysis of the characteristics of cracked teeth and evaluation of pulp status according to periodontal probing depth
by
Jo, A-Ra
,
Kim, Sin-Young
,
Yang, Sung-Eun
in
Care and treatment
,
Characteristics
,
Cracked teeth
2017
Background
The purpose of this study was to analyze the characteristics of cracked teeth and to evaluate pulp status according to periodontal probing depth (PPD).
Methods
A total of 182 cracked teeth were included. The location and type of the cracked teeth, age and gender of the patients, restoration type, pulp status, PPD, and radiographic findings were analyzed.
Results
Mandibular second molars (25.3%) were the most frequently involved teeth, followed by mandibular first molars (22.5%), maxillary first molars (22.0%), and maxillary second molars (17.6%). The patient age was most frequently 50–59 years. Cracks occurred mainly in nonbonded restorations, such as gold (26.9%), and were usually found in intact teeth (37.9%). A total of 103 teeth (56.6%) had an initial PPD of less than 3 mm, while 40 (22.0%) had a PPD of 4–6 mm, and 39 (21.4%) had PPD of 7 mm or more. A total of 33 cracked teeth (18.1%) were diagnosed with pulp necrosis, 40 (22.0%) with irreversible pulpitis, and 97 (53.3%) with reversible pulpitis. The incidence of pulp necrosis was 31.8% among cracked teeth with a PPD of 4–6 mm, and 28.6% among those with a PPD of 7 mm or more.
Conclusions
Cracks occurred mainly in molar teeth, and were commonly found in intact teeth with no restoration. Patients with cracked teeth were most frequently aged 50–59 years. Cracked teeth showing a PPD of more than 4 mm were more likely to show pulp necrosis.
Journal Article
Influence of Luting Materials and Methods and the Restoration Surface on the Amount of Cement Remnants in Implant Restorations
2019
This study aimed to investigate the effects of the luting methods on the amount of cement remnants in implant restorations and to determine the restoration surface with the maximum amount of residual cement. Forty abutments and crowns were divided into 4 groups as follows: TB group, luting with zinc oxide-eugenol cement; TBV group, luting with zinc oxide-eugenol cement after application of a separating agent over the transmucosal area of the abutment; PI group, luting with methacrylate cement; and PIV group, luting with methacrylate cement after application of a separating agent. After cementation, all the quadrants of the specimens were photographed, and the amount and location of the cement remnants were statistically analyzed ( P ≤ .05). The amount of cement remnants was significantly smaller in the groups with a separating agent. The type of luting material did not significantly affect the results. Cement remnants were more abundant on the mesial and distal sides than on the buccal and lingual sides of the restoration.
Journal Article
Rapid development of a DNA vaccine for Zika virus
by
Yang, Eun Sung
,
Higgs, Stephen
,
De La Barrera, Rafael
in
Animals
,
Antibodies, Neutralizing - blood
,
Antibodies, Neutralizing - immunology
2016
Zika virus (ZIKV) was identified as a cause of congenital disease during the explosive outbreak in the Americas and Caribbean that began in 2015. Because of the ongoing fetal risk from endemic disease and travel-related exposures, a vaccine to prevent viremia in women of childbearing age and their partners is imperative. We found that vaccination with DNA expressing the premembrane and envelope proteins of ZIKV was immunogenic in mice and nonhuman primates, and protection against viremia after ZIKV challenge correlated with serum neutralizing activity. These data not only indicate that DNA vaccination could be a successful approach to protect against ZIKV infection, but also suggest a protective threshold of vaccineinduced neutralizing activity that prevents viremia after acute infection.
Journal Article
Mosaic nanoparticle display of diverse influenza virus hemagglutinins elicits broad B cell responses
by
Yang, Eun Sung
,
Boyoglu-Barnum, Seyhan
,
Kong, Wing-Pui
in
631/250/2152/2153/1291
,
631/326/596/1578
,
631/61/24/590/2294
2019
The present vaccine against influenza virus has the inevitable risk of antigenic discordance between the vaccine and the circulating strains, which diminishes vaccine efficacy. This necessitates new approaches that provide broader protection against influenza. Here we designed a vaccine using the hypervariable receptor-binding domain (RBD) of viral hemagglutinin displayed on a nanoparticle (np) able to elicit antibody responses that neutralize H1N1 influenza viruses spanning over 90 years. Co-display of RBDs from multiple strains across time, so that the adjacent RBDs are heterotypic, provides an avidity advantage to cross-reactive B cells. Immunization with the mosaic RBD–np elicited broader antibody responses than those induced by an admixture of nanoparticles encompassing the same set of RBDs as separate homotypic arrays. Furthermore, we identified a broadly neutralizing monoclonal antibody in a mouse immunized with mosaic RBD–np. The mosaic antigen array signifies a unique approach that subverts monotypic immunodominance and allows otherwise subdominant cross-reactive B cell responses to emerge.
Antigenic variation of influenza A viruses necessitates the annual reformulation of vaccines. Kanekiyo et al. develop a mosaic nanoparticle vaccine against influenza virus that is able to elicit neutralizing antibodies that span nearly 100 years of variation of influenza A virus.
Journal Article
A platform incorporating trimeric antigens into self-assembling nanoparticles reveals SARS-CoV-2-spike nanoparticles to elicit substantially higher neutralizing responses than spike alone
by
Corbett, Kizzmekia S.
,
Zhang, Baoshan
,
Yang, Eun Sung
in
631/45/535/1258/1259
,
692/699/255/2514
,
Animals
2020
Antigens displayed on self-assembling nanoparticles can stimulate strong immune responses and have been playing an increasingly prominent role in structure-based vaccines. However, the development of such immunogens is often complicated by inefficiencies in their production. To alleviate this issue, we developed a plug-and-play platform using the spontaneous isopeptide-bond formation of the SpyTag:SpyCatcher system to display trimeric antigens on self-assembling nanoparticles, including the 60-subunit
Aquifex aeolicus
lumazine synthase (LuS) and the 24-subunit
Helicobacter pylori
ferritin. LuS and ferritin coupled to SpyTag expressed well in a mammalian expression system when an
N-
linked glycan was added to the nanoparticle surface. The respiratory syncytial virus fusion (F) glycoprotein trimer—stabilized in the prefusion conformation and fused with SpyCatcher—could be efficiently conjugated to LuS-SpyTag or ferritin-SpyTag, enabling multivalent display of F trimers with prefusion antigenicity. Similarly, F-glycoprotein trimers from human parainfluenza virus-type 3 and spike-glycoprotein trimers from SARS-CoV-2 could be displayed on LuS nanoparticles with decent yield and antigenicity. Notably, murine vaccination with 0.08 µg of SARS-CoV-2 spike-LuS nanoparticle elicited similar neutralizing responses as 2.0 µg of spike, which was ~ 25-fold higher on a weight-per-weight basis. The versatile platform described here thus allows for multivalent plug-and-play presentation on self-assembling nanoparticles of trimeric viral antigens, with SARS-CoV-2 spike-LuS nanoparticles inducing particularly potent neutralizing responses.
Journal Article
Mesenchymal stem cells feeder layer from human umbilical cord blood for ex vivo expanded growth and proliferation of hematopoietic progenitor cells
by
Jang, Yun Kyung
,
Yoo, Keon Hee
,
Jung, Dai Hyun
in
Antigens, CD34 - analysis
,
Antigens, CD34 - biosynthesis
,
Bone marrow
2006
Ex vivo expansion of hematopoietic stem cells was suggested as the best way of overcoming problems caused by limited hematopoietic cell number for cord blood transplantation. In this study, we quantified and characterized an ex vivo expansion capacity of umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) as a cell feeder layer for support of UCB-derived committed hematopoietic progenitor cells (HPCs) in the absence or presence of recombinant cytokines. The UCB-derived MSCs used in the study differentiated into osteoblast, chondrocytes, and adipocytes under proper conditions. Frequencies in colony forming unit-granulocyte, macrophage, colony forming unit-granulocyte, erythrocyte, macrophage, megakaryocyte, burst forming unit-erythrocyte, and colony forming unit-erythrocyte increased to 3.46-, 9.85-, 3.64-, and 2.03-folds, respectively, only in culture supplemented by UCB-derived MSCs as a cell feeder layer without recombinant cytokines (culture condition C). Identified expansion kinetics in all kinds of committed HPCs showed plateaus at 7 culture days, suggesting some consumable components were required for the expansion. Physiological importance and different roles for different committed HPCs of UCB-derived MSCs as a cell feeder layer were revealed by a distinguished expansion capacity for colony forming unit-megakaryocyte. The preferred maintenance of CD33(-)CD34(+) in culture condition C was also identified. The presence of cobblestone-like areas as hematopoietic microenvironment and various cell feeder layer-originated hematopoietic cytokines including interleukin-1beta and granulocyte, macrophage-colony stimulating factor were suggested as underlying mechanisms for the identified expansion capacity. The present numeric and biological information about intrinsic expansion capacity for UCB-derived committed HPCs will increase further biological and clinical applications of UCB-derived MSCs.
Journal Article
Single-dose bNAb cocktail or abbreviated ART post-exposure regimens achieve tight SHIV control without adaptive immunity
2020
Vertical transmission accounts for most human immunodeficiency virus (HIV) infection in children, and treatments for newborns are needed to abrogate infection or limit disease progression. We showed previously that short-term broadly neutralizing antibody (bNAb) therapy given 24 h after oral exposure cleared simian-human immunodeficiency virus (SHIV) in a macaque model of perinatal infection. Here, we report that all infants given either a single dose of bNAbs at 30 h, or a 21-day triple-drug ART regimen at 48 h, are aviremic with almost no virus in tissues. In contrast, bNAb treatment beginning at 48 h leads to tight control without adaptive immune responses in half of animals. We conclude that both bNAbs and ART mediate effective post-exposure prophylaxis in infant macaques within 30–48 h of oral SHIV exposure. Our findings suggest that optimizing the treatment regimen may extend the window of opportunity for preventing perinatal HIV infection when treatment is delayed.
Broadly neutralizing antibodies (bNAbs) are being evaluated for HIV post-exposure prophylaxis (PEP) in the setting of vertical transmission. Here, using a macaque model of perinatal SHIV infection, the authors show that PEP for infant macaques within 30–48 h of SHIV exposure is highly effective using either bNAbs or ART.
Journal Article