bluuebunny/crossref_metadata_2025_split huggingface dataset:
264. Resident Macrophages of the Amnion: Characterization and Response to Ascending Bacterial Pathogens
Authors: Fandozzi Eva , Smith Caroline , Megli Christina 
Published: November 2023

Abstract

Background
The primary organ of pregnancy, the placenta, exists as a maternal-fetal barrier and displays remarkable immunoactivity. This barrier is effective against multiple pathogens, yet, the underlying mechanisms of immune regulation and pathogen defense of this barrier are not well understood. The inner layer of the fetal membrane, the amnion, has been proposed to be a significant barrier to infection. The amnion has been reported to contain CD14+ cells, but the immune activity and localization of these cells are poorly characterized. As a monocyte marker, these CD14+ cells may be endemic to the amnion and involved in antimicrobial defenses.

Methods
We isolate macrophages from amnion explants of fetal membranes collected at cesarean section in the absence of labor and infection using a StemSep Human CD14+ Selection Kit. These cells are characterized using flow cytometry and FACS. In addition, mCherry labeled L. monocytogenes (LM) or CFSE labeled S. agalactiae (GBS) were used to infect intact explants and infectivity was quantified by colony forming units. Immunofluorescence staining was used to localize CD14. Bacteria colonization with CD14 was visualized in infected tissue explants. CD86 and CD163 were used as M1 and M2 markers respectively. Imaging was performed using the STELLARIS confocal microscope.

Results
CD14+ cells exist in healthy amniotic tissue explants and localize to the mesenchymal layer. Amnion CD14+ cells also co-localize with CD86 and without CD163 suggesting a distinct phenotype from other placental macrophages (Hoffbauer cells and PAMM subsets). Amnion explants have decreased growth of LM and GBS in comparison to chorion and chorionic villi. LM and GBS co-localized with CD14+ cells in the amnion.
CD14+ macrophages are present in healthy amnion explants
Immunofluorescence staining of healthy human amnion. CD14 (green) positive cells localize to the mesenchymal layer of the amnion. Nuclei and cytoplasmic actin are stained with DAPI (blue) and phalloidin (red) respectively.
GBS localizes to the mesenchymal layer of the amnion

Immunofluorescence staining of healthy human amnion. GBS (green) localizes to the mesenchymal layer of the amnion. Nuclei and cytoplasmic actin are stained with DAPI (blue) and phalloidin (red) respectively.

Conclusion
We present the novel finding of resident macrophages in the amnion and demonstrate the presence of amnion macrophages in the absence of infection. In addition, we demonstrate that these macrophages express CD86 and co-localize with bacteria that can be vertically transmitted during pregnancy, including LM and GBS. Further characterization of the regulation of these cells may provide insight into the immunomodulatory function of the fetal membrane.

Disclosures
All Authors: No reported disclosures
269. Reference Data of Biochemical and Hematology Parameters in Juvenile and Adult Owl Monkeys (Aotus nancymaae) for Biomedical Research
Authors: Carlos Gaspar Juan , Moeller Tyler , Buchta Jessica , Nieto Monica , Espinoza Nereyda , Castillo Rosa , Nunez Rosa 
Published: November 2023

Abstract

Background
Non-human primates (NHP), including New World monkeys (NWM), are used in varied fields of biomedical research encompassing infectious disease, behavioral sciences and drug and vaccine development. In these studies, normal reference values for biochemical and hematological parameters are often needed for comparison with experimental results. These blood parameters are useful guides in reaching a diagnosis, estimating the prognosis of the disease and monitoring the progress of treatment. Although there are various reports of biochemical and hematologic parameters in Old World monkeys, the range of reference values often differs between NHP species. Despite the importance of NWMs such as Aotus nancymaae in biomedical research, few studies have examined these values and with a limited number of animals only. A. nancymaae is widely used for research and often used to study the principal types of human malaria (P. falciparum and P. vivax). These primates have also been used to study leishmaniasis, schistosomiasis, tuberculosis and various types of enteric infections. Furthermore, in recent years oral challenge models have been developed in A. nancymaae for Campylobacter jejuni, Shigella flexneri, and Enterotoxigenic Escherichia coli (ETEC). However, there is no updated data on biochemical and hematological parameters for A. nancymaae. Therefore, the aim of this study was to provide complete and accurate reference intervals of biochemical and hematological values to assess the health status indices of A. nancymaae housed in a vivarium prior to their use.

Methods
To characterize these parameters, a total of 1250 blood samples (1003 from juvenile and 247 from adult monkeys) were analyzed between 2007 to 2022. A total of 14 biochemical and 20 hematology parameters were measured.

Results
A significant change was observed in the values of alkaline phosphatase (ALP), potassium (K+), glucose (GLU), blood urea nitrogen (BUN), creatinine (CRE), hemoglobin (HGB) and lymphocyte (LYM) in relation to sex and age.

Conclusion
In conclusion, this work establishes a comprehensive and systematic reference of serum biochemical and hematological parameters for A. nancymaae based on a large cohort which can be used to inform and guide future studies utilizing this animal model.

Disclosures
All Authors: No reported disclosures
314. Using CRISPR/Cas9 to dissect the regions of MLL/AF9 that are critical for myeloid immortalization
Authors: Yvanovich Emma , Timmer Kyle , Mansour Michael , Sykes David B 
Published: November 2023

Abstract

Background
High volumes of neutrophils are required for the successful granulocyte transfusion. Our goal is to expand neutrophil progenitors ex vivo to provide white blood cell transfusions of sufficient cell number. Creating a conditionally immortalized granulocyte-monocyte progenitor (GMP) would allow for exploration into the infinite expansion of GMPs to make a large volume of neutrophils.
The MLL/AF9 fusion oncoprotein is associated with mixed lineage leukemia (MLL), a form of acute myeloid leukemia (AML). MLL1 is a large gene with multiple binding sites associated with the development of MLL when broken and bound to a fusion parnter like AF9, highly efficient at causing MLL. We would like to understand whether certain regions of the gene might provide the capacity for ex vivo expansion without resulting in leukemia.

Methods
To determine the most relevant portion of the MLL/AF9 gene, we conducted a "walkdown" with a custom CRISPR/Cas9 gRNA library to identify elements crucial for immortalization. The Cas9 and gRNAs will be delivered by lentiviral transduction. This walkdown employs a custom gRNA library with guides targeting each base pair along the ∼6000bp coding region. Transduction of MLL/AF9 dependent human leukemia cell lines THP1 and MOLM13 will be performed to identify those gRNA that target essential regions of MLL/AF9 in this drop-out screening approach.

Results
Pilot experiments have been conducted to increase transduction efficiency for MLL/AF9 dependent cells. Transduction efficiency was maximized at 4 viral particles per cell in a 96 well plate (Figure 1). A larger scale walkdown pilot was conducted to maximize the amount of gDNA collected for PCR amplification. Sequencing of the PCR product will identify cells with essential areas knocked out (Figure 2).
Figure 1
GFP positivity in transduced MLL/AF9 cells in differing plate sizes displayed in two formats.
Figure 2
Predicted results of the walkdown experiment sequencing analysis.

Conclusion
The association of the MLL/AF9 fusion oncogene with myeloid lineage leukemia offers a natural mechanism through which to study GMP immortalization. Specific areas of the coding region can be identified by conducted a "walkdown" experiment with CRISPR/Cas9 gRNA library to knock out each base pair of the oncogene. Regions of the gene can be identified as essential to survival when cells with these areas knocked out die off. Manipulation of these essential areas can be used for further study in the immortalization of GMPs.

Disclosures
Michael Mansour, MD, PhD, Thermofisher: Grant/Research Support
317. Implementing lifestyle medicine innovations for preventing and reversing chronic diseases in HIV care at a Federally Qualified Healthcare Center
Authors: Anand Rahul , Prabhu Shagun S , Ingram Valerie R , Pevar Elena , Brown Orett 
Published: November 2023

Abstract

Background
Patients living with HIV are a vulnerable population, with high burden of chronic diseases and challenging social determinants of health. Many receive care in Ryan White grant funded multidisciplinary clinics in the community providing an opportunity to reimagine care delivery using innovative practices like shared medical appointments (SMAs). We designed and implemented lifestyle medicine (LM) interventions using interprofessional teams including one of the first described SMA programs for patients with HIV. Our pilot describes an iterative patient-centered model transferable and scalable to other HIV clinics or FQHCs for delivering lifestyle medicine to patients with HIV and other chronic infections.
Learning objectives of oral presentation
Learning objectives
Shared medical appointments recruitment flyer
Recruitment flyer

Methods
We piloted LM interventions both in individual patient care and via SMAs using interprofessional teams (physician, nutritionist, case managers). SMAs were 90 minutes long, designed to include 5-15 patients conducted monthly focusing on one pillar of LM at each event (nutrition,activity,sleep,stress,relationships,substance use). A whole health questionnaire was completed at the initial session, and American College of Lifestyle Medicine (ACLM) self-assessment on various pillars of lifestyle completed each session. Participants created a goal at the end of each session, and shared progress and key takeaways on return. Session guides were created for each session.
Lifestyle assessment page 1 of 2
Lifestyle assessment page 2 of 2

Results
Serial assessments at SMAs demonstrated tangible and sustained changes in various pillars of LM. Patient feedback indicated high patient and provider satisfaction; patients found group visits “grounding” in their lives. Disclosing HIV status to other patients was not considered a barrier by any attendees. Other key lessons learned include the benefit of social support for patients, ease of conducting repeated assessments of the six pillars of LM using ACLM form, benefit of creating session detailed guides for future iterations and scalability, and the importance of signing up an adequate number of patients for financial sustainability.
Lifestyle medicine shared medical appointments outcomes graphic
SMA Outcomes
Pre vs post program assessment data details for consenting patients
Pre vs Post program assessment data

Conclusion
Our pilot provides an iterative patient-centered model of SMAs easily transferable and scalable to other practices for delivering lifestyle medicine care to impact chronic diseases affecting patients with HIV and other vulnerable populations.

Disclosures
Rahul Anand, MD MBA MSCI, Paratek pharmaceuticals: Stocks/Bonds
318. Beta-lactam Therapeutic Drug Monitoring Improves Attainment of Target Drug Levels in Critically Ill Patients
Authors: Ausman Sara , Braga Shienna , Hagy Natalie T , Rivera (O'Connor) Christina G , Moreland-Head Lindsay , Rebecca Wessel , Abu Saleh Omar M , Rule Andrew D , Gajic ognjen , Barreto Erin F 
Published: November 2023

Abstract

Background
Critically ill patients, particularly those treated with extracorporeal devices or at extremes of weight, experience pharmacokinetic variability which can compromise beta-lactam (BL) antibiotic target attainment and treatment response. Therapeutic drug monitoring (TDM) for BL antibiotics can improve precision pharmacotherapy but has had limited implementation. The objective of this study was to evaluate the frequency of BL target attainment among adult intensive care unit (ICU) patients who underwent TDM.

Methods
This observational study evaluated adults treated with cefepime, piperacillin/tazobactam or meropenem in ICUs at the Mayo Clinic in Rochester, Minnesota who underwent TDM from June-September 2022. During the study timeframe, multidisciplinary teams were encouraged to perform BL TDM on patients requiring extracorporeal membrane oxygenation, continuous kidney replacement therapy, or at an extreme of body weight (weight &lt; 40 kg or &gt;120 kg or BMI &lt; 18 kg/m2 or &gt; 40 kg/m2). Percentage of patients with initial serum trough concentrations within the therapeutic range was calculated (Table 1).

Results
During the study timeframe, 59 trough concentrations were performed on critically ill patients, of which 5 were excluded due to uninterpretable results. Of the remaining 54 BL trough concentrations analyzed, 49 (91%) were initial troughs during the antibiotic course, and 5 (9%) were repeat troughs. Thirty-six (73%) of the initial trough concentrations were within the therapeutic range. Among the trough concentrations outside the therapeutic range, 10 (77%) were too high, and 3 (23%) were too low (Table 2). Dose adjustment occurred in 19 (39%) of initial trough evaluations, including 6 which were adjusted despite a level within the therapeutic range. All of the repeat trough concentrations drawn during the same antibiotic course were within the therapeutic range (n = 5/5; 100%).

Conclusion
One-fourth of initial BL trough concentrations were outside of the therapeutic range. BL levels outside the therapeutic range prompted dose adjustment to improve the potential for effectiveness or limit the potential for toxicity. BL TDM appears to be a promising strategy to enhance precision pharmacotherapy in the critically ill.

Disclosures
Sara Ausman, PharmD, Gilead: Honoraria Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria
330. Outpatient Parenteral Antimicrobial Therapy in People who Inject Drugs
Authors: Hawes Armani , Yanek Lisa , Buresh Megan E , Bodnar Alia , Keller Sara C 
Published: November 2023

Abstract

Background
People with opioid use disorder (OUD) make up a significant and increasing proportion patients requiring outpatient parenteral antimicrobial therapy (OPAT). Many of these patients do not receive OUD treatment during their index hospitalization, leading to missed opportunities for treatment, recurrent hospitalizations, worse outcomes, and increased costs. We describe predictors of addiction medicine consultation among people with OUD requiring OPAT, and the impact of addiction medicine consultation on receipt of medications for opioid use disorder (MOUD) after discharge.

Methods
We reviewed records from 172 patients with OUD who were discharged on OPAT from Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center 4/2020-9/2022. We described differences between those who received and did not receive inpatient addiction medicine consults by demographics, service (medicine vs surgical), type of insurance, type of infection, disposition, and addiction treatment.

Results
The addiction medicine team was consulted for 120 patients and was not consulted for 46 patients. Addiction medicine was more likely to be consulted on younger patients (43.3 years vs 48.3 years, p=0.01), for patients with endovascular infections (23.3% vs 2.3%, p&lt; 0.01) or bloodstream infections (31.9% vs 13.6%, p=0.02), and when the infectious organism was methicillin-resistant Staphylococcus aureus (40.7% vs 20.9%, p=0.02). When the addiction medicine team was consulted, patients were more likely to be discharged on MOUD, specifically buprenorphine (32.5% vs 17.4%, p&lt; 0.01) or methadone (57.5% vs 39.1%, p&lt; 0.01). Overall, most patients were discharged to a skilled nursing facility (SNF), but patients who received addiction medicine team consult were more likely to be discharged to SNF than home (92.9% vs 7.0%, p&lt; 0.01). Patients discharged to SNF were less likely to have a 30 day readmission compared to patients discharged home (14.4% vs 32.0%, p=0.03).

Conclusion
Addiction medicine consultations were associated with an increased likelihood of evidence-based MOUD among patients with OUD requiring OPAT. By maximizing the resources of the addiction medicine team, we hope to improve outcomes for patients with opioid use disorder who require OPAT.

Disclosures
Sara C. Keller, MD, MPH, MSPH, Pfizer: Advisor/Consultant
345. Unaccounted Costs Associated with Different Outpatient Parenteral Antimicrobial Therapy (OPAT) Models of Care
Authors: Player Jacob , Bouzigard Rory , Arnold Mark , Mang Norman S , Hall Brenton , Lane Michael , Perl Trish M , Castellino Laila M 
Published: November 2023

Abstract

Background
OPAT decreases length of stay/inpatient costs while benefiting patients. However, OPAT costs incurred in the ambulatory setting are poorly quantified. We evaluated unaccounted costs and potential savings from OPAT delivered via patient self-administration (S-OPAT), home care agencies/hemodialysis centers (HH-OPAT), and skilled nursing facilities (SNF-OPAT).

Methods
The electronic health record (EHR) for all adult patients discharged on OPAT from Parkland Hospital (PH), a 900-bed safety-net hospital, during April - June 2021 and January - March 2022 was reviewed for the number and duration of antibiotics administered and post-discharge non-billable encounters (defined as an encounter on any day without a corresponding billable visit). Encounters on the day of a billable visit were excluded. Inpatient days avoided were defined as days post-discharge on which the patient received OPAT. An average daily hospital adjusted expense per inpatient day of $3,764 for Texas state hospitals and wholesale acquisition cost data from the Texas Department of State Health Services were used to estimate cost savings from OPAT. 340B pricing was used to calculate the cost of drugs provided to S-OPAT patients by PH. Antibiotics with different formulations were converted to equivalent daily doses and costs were averaged to estimate a daily antibiotic cost. The institutional IRB approved this study.

Results
Of 340 patients, 84 (25%) received SNF-OPAT, 115 (34%) HH-OPAT, and 141 (41%) S-OPAT. There were 255 non-billable encounters in the S-OPAT group, 242 in the HH-OPAT, and 220 in the SNF-OPAT group, with the highest rate per 100 person-days in SNF-OPAT recipients (Table 1), nearly twice that of S-OPAT. Antibiotic costs avoided by discharging patients on OPAT were $383,240 for HH-OPAT patients and $505,588 for SNF-OPAT patients (Table 2). For S-OPAT patients, costs incurred by PH based on 340B pricing were $33,785.

Conclusion
All OPAT care models saved costs compared to hospitalization. Our study likely underestimates the unaccounted costs associated with OPAT; however, costs incurred may be significant and differ between care models. Personnel time and non-billable work should additionally be considered in determining true OPAT cost.

Disclosures
All Authors: No reported disclosures
360. A First-in-Human Study to Assess the Safety, Tolerability, Pharmacokinetics, and Neutralization Profile of Two Long-Acting Anti-SARS-CoV-2 Monoclonal Antibodies
Authors: Asiago Josephat , Albizem Moetaz , Tieu Holly L , Stecco Kathryn , Moullan Norman , Fenwick Craig , Lin Kai , Poffenbarger Lauren , Lengsfeld Thomas , Liu David W , Hock Björn M , Venkayya Rajeev , Bhuyan Prakash 
Published: November 2023

Abstract

Background
COVID-19 remains a significant risk to the immunodeficient population, which is more vulnerable to severe consequences and less likely to mount a protective immune response following vaccination. Monoclonal antibodies (mAbs) have been effective and safe, but the emergence of omicron and its subvariants has created an unmet need for new broadly protective and long-acting agents.
AER001 and AER002 are human immunoglobulin-G1 under development for pre-exposure prophylaxis and treatment of COVID-19. These mAbs were isolated from persons previously infected and/or vaccinated against SARS-CoV-2. AER001 and AER002 bind to the receptor binding domain of the spike protein on non-overlapping epitopes and compete with angiotensin converting enzyme-2 (ACE-2) to block viral attachment. AER002 showed strong in vitro neutralization activity against omicron strains including BA.2.12.1, BA.4 and BA.5.

Methods
The study is a phase I, randomized, double-blind, placebo-controlled, dose escalation study in healthy adults (n=80) with a primary objective to evaluate the safety and tolerability of the combination of AER001 and AER002 or AER002 alone vs placebo, administered intravenous with dose ranging (100 mg to 1200 mg). The secondary objectives are to assess pharmacokinetics (PK)s, anti-drug antibodies (ADA)s, and neutralization activity levels and safety evaluation through 6-months of follow-up.

Results
As of 21 March 2023, enrolment was completed. A total of 154 adverse events (AE)s were reported in 62 subjects. Most frequent AEs were infusion-related site reactions (IRSRs) 20.13% (31/154), headache 16.23% (25/154) and common cold 10.39% (16/154). Most (98.7%) of the reported AEs were grade 1 (mild) severity. There were no serious adverse events (SAE)s or ADAs and 2 non-AE-associated discontinuations. Only 1.3% (2/154) AEs (IRSRs, erythema and tenderness) were rated as possibly related to the investigational products by the principal investigator.

Conclusion
Based upon preliminary data, AER001 and AER002 show adequate safety with no SAEs or ADAs. Complete safety and PK data through 6 months will be presented at the meeting.

Disclosures
Moetaz Albizem, MD, Regeneron: Stocks/Bonds Norman Moullan, PhD, Aerium Therapeutics: Stocks/Bonds Kai Lin, PhD, Aerium Therapeutics: Employee