bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular recognition of a single-chain Fv antibody specific for GA-pyridine, an advanced glycation end-product (AGE), elucidated using biophysical techniques and synthetic antigen analogues
Authors: Kobashigawa Yoshihiro , Ohara Toshiya , Morita Kosuke , Toyota Yuya , Nakamura Teruya , Kotani Shunsuke , Arimori Takao , Yamauchi Soichiro , Liu Chenjiang , Kitazaki Masaya , Wakeyama-Miyazaki Yukari , Suwa Yoshiaki , Uchida-Kamekura Makiyo , Fukuda Natsuki , Sato Takashi , Nakajima Makoto , Takagi Junichi , Yamagata Yuriko , Morioka Hiroshi 
Published: June 2021

Abstract
Advanced glycation end-products (AGEs) are a heterogeneous group of compounds formed by non-enzymatic reaction between reducing-sugar and Arg/Lys in proteins and are involved in various diabetic complications. GA-pyridine is derived from glycolaldehyde and is one of the most cytotoxic AGEs. Here, we established a single-chain Fv (scFv) antibody against GA-pyridine, 73MuL9-scFv, and examined the details of its specificity and antigen recognition by using various techniques involving biophysics, chemical biology and structural biology. We also synthesized several compounds that differ slightly in regard to the position and number of GA-pyridine substituent groups, and revealed that GA-pyridine was specifically bound to 73MuL9-scFv. Thermodynamic analysis revealed that the association of GA-pyridine to 73MuL9-scFv was an exothermic and enthalpy driven reaction, and thus that the antigen recognition involved multiple specific interactions. Crystallographic analysis of the Fv fragment of 73MuL9-scFv revealed that several CH-π and hydrogen bond interactions took place between the Fv-fragment and GA-pyridine, which was consistent with the results of thermodynamic analysis. Further studies using 73MuL9-scFv as a tool to clarify the relevance of GA-pyridine to diabetic complications are warranted.
#4: Antibiotic Durations for Skin and Soft Tissue Infections in Pediatric Urgent Care Clinics
Authors: Hamner Megan , Nedved Amanda , Austin Holly , Wyly Donna , Burns Alaina , King Diana , Lee Brian , El Feghaly Rana E 
Published: June 2021

Abstract

Background
Skin and soft tissue infections (SSTIs) are the second most common diagnosis leading to pediatric antibiotic prescriptions in the outpatient setting after respiratory diagnoses. However, most antibiotic stewardship programs have mainly focused on the latter. Children seen in the ambulatory setting for SSTIs often receive &gt;7 days of antibiotics, although current society guidelines recommend 5–7 days for most diagnoses.

Objectives
To determine the baseline percentage of patients receiving antibiotic prescriptions for &gt;7 days for SSTIs in urgent care clinics (UCC)s of a pediatric health system and to evaluate factors that influence providers towards longer durations.

Methods
We built a report that extracted patient encounters from the three UCCs based on International Classification of Diseases (ICD)-10 codes for common SSTIs including impetigo, abscesses, cellulitis, erysipelas, folliculitis, paronychia, and animal bites. Data was pulled from June 2019 through June 2020. The report included patient age, concomitant diagnoses, antibiotics prescribed and their duration. We excluded encounters if the patient was transferred to the emergency department or admitted, the patient was younger than 3 months of age, no antibiotics were prescribed, or if there was a concurrent infectious diagnosis affecting antibiotic duration. We sent a 22-question survey to UCC providers to understand prescribing habits particularly focusing on factors prompting administration of longer antibiotic courses.

Findings
From June 2019-June 2020, we reviewed 2,575 encounters; we excluded 208 of those (8%). 823 (35%) of patients received &gt;7 days of antibiotics for SSTIs while 1181 (50%) received 5–7 days and 35 (1%) received &lt;5 days of antibiotics. 328 (14%) received topical therapy only. Most common antibiotics prescribed included cephalexin, clindamycin, and trimethoprim-sulfamethoxazole. A mild improvement in the 5–7 days duration was noted through our study period (Figure 1). The survey was sent to 50 providers with 27 responding (54% response rate). Of providers surveyed, 5 (19%), 7 (26%), and 8 (29%), expressed being uncomfortable with a 5-day treatment course for cellulitis, erysipelas, and abscesses respectively. Barriers for shorter treatment courses included concern for acute rheumatic fever development, parental pressure, fear of complications, and accustomed antibiotic duration.

Conclusion
A third of children with SSTIs in our UCCs receive long courses of antibiotics. A mild improvement noted in our study period may be due to existing antibiotic stewardship interventions. Specific provider concerns leading to overprescribing will be targeted by quality improvement efforts.
#13: Respiratory and Intestinal Epithelial Cells Exhibit Differential Susceptibility and Innate Immune Responses to Contemporary EV-D68 Isolates
Authors: Freeman Megan Culler , Wells Alexandra I , Ciomperlik-Patton Jessica , Myerburg Michael M , Anstadt Jennifer , Coyne Carolyn B 
Published: June 2021

Abstract

Background
Enterovirus D68 (EV-D68) has been implicated in outbreaks of severe respiratory illness and associated with acute flaccid myelitis (AFM), a disease which causes paralysis in previously healthy patients, mostly children. AFM peaked in even numbered years, at least 2014–2018. While 2020 was expected to be a peak AFM year, few cases were seen, likely due to non-specific social distancing measures due to SARS-CoV-2. EV-D68 is primarily described as a respiratory pathogen, in contrast to ‘classic’ enteroviruses that are spread via the fecal-oral route. However, similar to other enteroviruses, EV-D68 has been detected in wastewater, suggesting it might also have an enteric route of transmission.

Methods
We used a panel of EV-D68 isolates, including a historic isolate from 2009 and multiple contemporary isolates from AFM peak years to define dynamics of viral replication and host response to infection. We performed comparative studies in primary human bronchial epithelial cells grown at an air-liquid interface and in primary human stem-cell derived intestinal enteroids. These human primary cell-based models more accurately reflect the cells targeted by EV-D68 in vivo. We defined growth characteristics, temperature sensitivity, infection polarity, and acid sensitivity in these parallel models. We used unbiased Luminex-based multianalyte profiling and bulk RNA-sequencing to define the innate immune response in each model.

Results

Conclusions
Our findings suggest that a subset of contemporary isolates of EV-D68 have the potential to target both the human airway and gastrointestinal tracts as a potential route of infection, identifying a previously unrecognized potential route of infection as well as defining, for the first time, the innate immune response to infection in multiple relevant primary epithelial models.
These findings are highly significant and are the first to characterize the viral replication and host innate immune response to a diverse panel of historic and contemporary EV-D68 isolates in both the respiratory and intestinal tracts.
#17: Disease and Immunoprophylaxis Model of Human Nose Organoids to Study SARS-CoV-2 and RSV Infection
Authors: Rajan Anubama , Marie Aloisio Gina , Weaver Ashley Morgan , Jelinski Joseph , Johnson Hannah , McBride Trevor , Robertson Matthew , Melicoff-Portillo Ernestina , Kanthi Yerramilli Malli Rama , Zeng Xi-Lei , Yu Xiaomin , Stossi Fabio , Coarfa Cristian , Kotkar Shalaka , Blutt Sarah , Estes Mary K , Avadhanula Vasanthi , Piedra Pedro A 
Published: June 2021

Abstract

Background
There is a significant and unmet need for pre-clinical models to predict responsiveness of immunotherapies to both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory syncytial virus (RSV) infection. Airway organoid models have been recently developed to study respiratory viruses; however, the current methods rely on invasive or biopsy derived samples to generate lung or airway organoids.

Objective
To establish human nose organoids (HNOs) as a model to study SARS-CoV-2 and RSV pathogenesis and test therapeutics.

Methods
We developed a non-invasive method to establish HNOs using stem cells isolated from nasal-wash and mid-turbinate samples. We made air liquid interface (ALI) cultures from undifferentiated 3-dimensional HNOs and differentiated for 21 days to form differentiated nasal epithelium. We inoculated the apical epithelium and assessed SARS-CoV-2 and RSV infection on the apical compartment using real time-polymerase chain reaction, plaque assays and immunofluorescence techniques. We then evaluated the feasibility of HNO-ALI model system to test the efficacy of serum antibodies to prevent SARS-CoV-2 infection and palivizumab monoclonal antibodies to prevent infection using palivizumab sensitive and resistant RSV strains. We introduced the antibodies in the basolateral compartment and monitored its neutralizing capacity on the apical side mimicking the neutralizing effects of antibodies in circulation.

Results
Our HNO-ALI cultures consist of well-differentiated, pseudostratified, ciliated, and mucosal respiratory epithelial cells and are susceptible to SARS-CoV-2, RSV A and B infection. SARS-CoV-2 and RSV replicates in the apical ciliated cells of the HNO-ALI cultures, peaks at 4 days, and plateaus at 8 days post infection. Infected HNO-ALI recapitulates aspects of SARS-CoV-2 and RSV disease, including viral shedding, asynchronous cilia beating/ciliary damage, and mucus hyper-secretion. Our model effectively showed protection to infection in a concentration dependent manner of the antibodies used.

Conclusion
We established a non-invasive method to generate HNO-ALI epithelial model as an authentic and an alternative model to 1-D cell culture systems. Our ex-vivo HNO-ALI infection model provides a novel approach for testing therapeutic interventions.
#31: Children with Invasive S. aureus Infection Produce Broadly Neutralizing Antibodies Against Distantly Related Variants of the Cytotoxin LukAB
Authors: Bennett Monique , Kose Nurgun , Perelman Sofya , Crowe James , Torres Victor , Thomsen Isaac 
Published: June 2021

Abstract

Background
Staphylococcus aureus is the most common invasive bacterial pathogen in children, and novel targets of intervention are urgently needed. The two-component leukotoxin, LukAB, is critical for S. aureus targeting and killing of human neutrophils and is abundantly produced in the setting of invasive human infection. LukAB is unique among S. aureus cytotoxins in that it exists in variant form across distantly related strains of clinically relevant S. aureus. The broad diversity of circulating clinical S. aureus strains must be taken into account to successfully develop new anti-staphylococcal preventives or therapeutics. This diversity and ongoing S. aureus evolution may explain previous unsuccessful attempts to intervene against S. aureus at the virulence factor level. We have previously shown that LukAB is ubiquitous among clinical isolates and that children with invasive disease mount a high-titer neutralizing response, but the breadth of function of this response has not previously been explored.

Methods
B-cells were isolated from children with invasive S. aureus infections (e.g. bacteremia or acute hematogenous osteomyelitis). Following EBV-transformation, cell supernatants were screened for LukAB binding and selected for generation of monoclonal hybridomas. MAbs were assessed for binding by ELISA and neutralizing function by in vitro cytotoxicity assays, where neutrophil-like HL-60 cells were cultured in the presence of human mAbs and diverse allelic variants of LukAB. The infecting S. aureus isolates were typed using multilocus sequence typing (MLST) to determine clonal complexes.

Results
34 distinct human anti-LukAB mAbs were generated from 3 children with invasive S. aureus disease. Of these, 22% were isolated following infection with a strain belonging to clonal complex 8 (CC8), consistent with the epidemic USA300 clone, and 78% were generated against CC5 strains. Within this panel, all mAbs potently neutralized LukAB from the same clonal complex as the corresponding infecting isolate, but 23 also demonstrated neutralization against other allelic variants of LukAB. 7 mAbs were capable of broad, potent neutralization against LukAB variants from all clinically relevant clonal complexes tested (CC8, CC30, CC45, CC75, CC1, CC5, and CC398).

Conclusions
A subset of human mAbs isolated from children with invasive S. aureus disease were capable of broad neutralization against distantly related variants of the important toxin LukAB. This has two important implications: First, we found strong evidence of a conserved target (or targets) for antibody-mediated toxin neutralization across diverse strains of S. aureus. Second, this provides additional support for this toxin as a target of intervention, as some previous vaccine attempts were likely unsuccessful due to activity against a narrow subset of circulating S. aureus strains.
#34: Characteristics of Pediatric Patients with Candidemia and Risk Factors for Disseminated Candidiasis
Authors: Leopold K E , Lloyd E C , Weinberg J B 
Published: June 2021

Abstract

Background
Candida species are the most common cause of fungal infection in hospitalized patients. Patients with candidemia are at risk of developing disseminated infection. Studies in adults have described risk factors for disseminated candidiasis in patients with candidemia, but there are fewer such studies in pediatric populations. The objective of the study is to examine the prevalence of disseminated candidiasis in pediatric patients with candidemia and to compare patients with disseminated candidiasis to those with candidemia alone.

Methods
All patients with blood cultures positive for a Candida species from 2007–2018 were identified from the UM Clinical Microbiology Laboratory. Retrospective chart review was conducted to gather demographic, clinical, and microbiologic data. Disseminated candidiasis was defined as ocular infection; endocarditis; renal, hepatic, or splenic involvement; peritonitis; or CNS infection. Patients with disseminated candidiasis were compared to those with candidemia alone using odds ratios.

Results
There were 81 episodes of candidemia during the study period, representing 61 unique patients. The most common comorbidity was intestinal failure (43%), and the presence of a central line (99%) and use of TPN (73%) were both highly prevalent. The most frequently identified Candida species was C. albicans, followed by C. parapsilosis. There were 14 patients (17%) with disseminated candidiasis. The most common site for dissemination was the abdomen (5 patients). Immunosuppressed patients were significantly more likely to have disseminated candidiasis (OR 4.1, 95% CI 1.1–15.3), while those with intestinal failure were significantly less likely to develop disseminated candidiasis (OR 0.07, 95% CI 0.01–0.6). Patients with disseminated candidiasis were significantly more likely to require ICU admission (OR 5.8, 95% CI 1.2–28) and were significantly more likely to die within three months of infection (OR 9.3, 95% CI 2.3–37.6) than those with candidemia alone.

Conclusions
The prevalence of disseminated candidiasis in patients with candidemia was 17%. Immunosuppression was positively associated and intestinal failure was negatively associated with the development of disseminated candidiasis. Patients with disseminated candidiasis had worse outcomes (including ICU admission and death) than those with candidemia alone. Our data suggest that immunosuppressed patients with candidemia should be thoroughly evaluated for signs of disseminated candidiasis.
#41: Mechanistic Immune Correlates of Protection Following Vaccination Against Rift Valley Fever Virus
Authors: Doyle Joshua D , Barbeau Dominique J , Cartwright Haley N , McElroy Anita K 
Published: June 2021

Abstract

Background
Rift Valley fever virus (RVFV) is a zoonotic arbovirus endemic to large areas of Africa and the Arabian peninsula that causes a significant annual burden of disease in ruminant animals, and is associated with periodic outbreaks in human populations. RVFV causes a wide spectrum of disease in infected patients ranging from a self-limiting febrile illness to hepatitis, encephalitis, hemorrhagic fever, and death. Despite the significant economic and public health impact of RVFV, there are no currently available vaccines or therapeutics available for RVFV.

Methods
Previous work has established that vaccination with an attenuated strain of RVFV, RVFV-ΔNSs, confers protection against subsequent lethal challenge in a murine model of infection. To characterize mechanistic immune correlates of protection, we vaccinated C57BL/6 mice with RVFV-ΔNSs then depleted vaccinated mice of various memory lymphocyte subsets, including CD4+, CD8+, CD4+/CD8+ T-cells before challenging mice with a lethal dose of WT RVFV. To assess for the role of antibodies in providing protection, we depleted mice of their B cells prior to vaccination with RVFV-ΔNSs, confirmed the lack of RVFV specific antibodies, and then challenged them with lethal WT RVFV. To determine the minimal immunologic factors required for protection, we vaccinated a series of donor mice, transferred either immunoglobulins or splenocytes to naïve recipient mice, then challenged them with WT RVFV.

Results
Vaccination with RVFV-ΔNSs protected mice from subsequent challenge, and this protection was not abrogated by depletion of CD4+, CD8+, or combined CD4+ and CD8+ lymphocytes, suggesting that RVFV-specific T-cells are dispensable for protection in the presence of virus specific antibodies. Vaccinated mice depleted of CD20+ B-cells were also protected against WT challenge, suggesting that B-cells/antibodies are also dispensable for protection in the presence of an intact T-cell response. Passive transfer of antibodies from vaccinated mice to recipient mice protected them against subsequent WT challenge, demonstrating that antibodies are sufficient for protection. Adoptive transfer of total splenocytes protected mice against subsequent WT challenge, indicating that lymphocytes are also sufficient to mediate protection.

Conclusions
In this study we defined the mechanistic immune correlates of protection following vaccination with attenuated RVFV-ΔNSs against WT RVFV in a murine model. Here, we have shown that both humoral and cellular immunity are sufficient to mediate protection in recipient animals, and can compensate for each other when one is missing. These results further our understanding of the protective immunologic response to infection by RVFV, and will help inform further vaccine development efforts against this important emerging pathogen.
#51: Neurotropic Astrovirus-VA1: Identifying the distinctions from classical genotypes
Authors: Davis Amy E , Hargest Virginia , Tan Shaoyuan , Jia Qidong , Cortez Valerie , Schultz-Cherry Stacey 
Published: June 2021

Abstract

Background
Human astroviruses (HAstV) are a leading cause of acute gastroenteritis in children, particularly those under the age of 2 or with immunosuppressive conditions. Indeed, our studies suggest that children with hematological malignancies are at high risk of infection. However, it has become increasingly clear that HAstV infections can also be associated with respiratory and even central nervous system (CNS) diseases. In the last decade, there have been at least 12 cases of astrovirus-induced CNS disease resulting in encephalitis and meningitis, including 2 St Jude patients. The CNS-associated infections are overwhelmingly fatal and are primarily caused by a novel astrovirus genotype, VA1, that is genetically more similar to animal astroviruses that also induce CNS-associated infections. The recent ability to propagate the VA1 strain in cell lines affords us the opportunity to better understand VA1 infection and how it compares to the better-studied HAstV1 strain.

Methods
Viral kinetics were determined by infection of human intestinal adenocarcinoma Caco-2 cells with either HAstV1 or VA1 and monitored for 24 hours post-infection (hpi). Infected cells were identified via immunofluorescent microscopy using antibodies against double-stranded RNA and viral capsid. Epithelial permeability of astrovirus-infected Caco-2 cells was measured using transepithelial electrical resistance (TER) and monitored for 24hpi. Nitazoxanide efficacy was identified by immunofluorescent analysis as described previously.

Results
Our findings demonstrate that HAstV1 and VA1 replicate in intestinal epithelial cells without inducing cell death or a pro-inflammatory cytokine response. However, these two strains have distinct replication kinetics. VA1 appears to have an ~8 hour lag in the expression of dsRNA and capsid protein compared to HAstV1 and does not require exogenous proteases to process the viral outer coat (capsid) protein, Additionally, we demonstrated that the increase in epithelial barrier permeability associated with HAstV1-infection is not found in VA1-infected cells, which is intriguing and may explain why HAstV1 is more likely to cause diarrhea. Of clinical importance, we have revealed a similar susceptibility of VA1 to the antiviral drug, nitazoxanide, which we have recently demonstrated its effectiveness inhibiting classical HAstV strains.

Conclusion
Overall, our studies highlight that VA1 pathogenesis is distinct from HAstV1, which could explain the differences in vivo. Future studies will be necessary to investigate viral replication and pathogenesis in distinct neuronal cells and in vivo.