Establishment of human post-vaccination SARS-CoV-2 standard reference sera.

There is a critical need to understand the effectiveness of serum elicited by different SARS-CoV-2 vaccines against SARS-CoV-2 variants. We describe the generation of reference reagents comprised of post-vaccination sera from recipients of different primary vaccines with or without different vaccine booster regimens in order to allow standardized characterization of SARS-CoV-2 neutralization in vitro. We prepared and pooled serum obtained from donors who received a either primary vaccine series alone, or a vaccination strategy that included primary and boosted immunization using available SARS-CoV-2 mRNA vaccines (BNT162b2, Pfizer and mRNA-1273, Moderna), replication-incompetent adenovirus type 26 vaccine (Ad26.COV2·S, Johnson and Johnson), or recombinant baculovirus-expressed spike protein in a nanoparticle vaccine plus Matrix-M adjuvant (NVX-CoV2373, Novavax). No subjects had a history of clinical SARS-CoV-2 infection, and sera were screened with confirmation that there were no nucleocapsid antibodies detected to suggest natural infection. Twice frozen sera were aliquoted, and serum antibodies were characterized for SARS-CoV-2 spike protein binding (estimated WHO antibody binding units/ml), spike protein competition for ACE-2 binding, and SARS-CoV-2 spike protein pseudotyped lentivirus transduction. These reagents are available for distribution to the research community (BEI Resources), and should allow the direct comparison of antibody neutralization results between different laboratories. Further, these sera are an important tool to evaluate the functional neutralization activity of vaccine-induced antibodies against emerging SARS-CoV-2 variants of concern. IMPORTANCE: The explosion of COVID-19 demonstrated how novel coronaviruses can rapidly spread and evolve following introduction into human hosts. The extent of vaccine- and infection-induced protection against infection and disease severity is reduced over time due to the fall in concentration, and due to emerging variants that have altered antibody binding regions on the viral envelope spike protein. Here, we pooled sera obtained from individuals who were immunized with different SARS-CoV-2 vaccines and who did not have clinical or serologic evidence of prior infection. The sera pools were characterized for direct spike protein binding, blockade of virus-receptor binding, and neutralization of spike protein pseudotyped lentiviruses. These sera pools were aliquoted and are available to allow inter-laboratory comparison of results and to provide a tool to determine the effectiveness of prior vaccines in recognizing and neutralizing emerging variants of concern.

Generation of an Alagille Syndrome (ALGS) patient-derived induced pluripotent stem cell line (TRNDi036-A) carrying a heterozygous mutation (p.Cys693*) in the JAG1 gene.

Alagille syndrome (ALGS) is an autosomal dominant, multisystemic disorder due to haploinsufficiency in JAG1 or less frequently, mutations in NOTCH2. The disease has been difficult to diagnose and treat due to variable expression. The generation of this iPSC line (TRNDi036-A) carrying a heterozygous mutation (p.Cys693*) in the JAG1 gene provides a means of studying the disease and developing novel therapeutics towards patient treatment.

Prevalence and associated risk factors of resistant hypertension among Chinese hypertensive patients in primary care setting.

INTRODUCTION: Hypertension (HT) is a major public health problem globally, and it is the commonest chronic disease with a prevalence of 27% among people aged 15 years or above in Hong Kong. There is emerging literature confirmed that patients with resistant hypertension (RHT) give its increased risk for adverse clinical outcomes and higher rate of documented target organ damage. This study aims to identify the prevalence of RHT among Chinese hypertensive patients managed in public primary care setting of Hong Kong and exploring its associated risk factors. METHODOLOGY: This is a cross-sectional descriptive study. Chinese hypertensive patients aged 30 or above with regular follow-up between 1st July 2019 and 30th June 2020 in 10 public primary care clinics under the Hospital Authority of Hong Kong were included. Demographic data, clinical parameters and drug profile of patients were retrieved from its computerized record system. The prevalence of RHT was identified and the associated risk factors of RHT were explored by multivariate logistic regression analysis. RESULTS: Among the 538 sampled Chinese hypertensive patients, the mean age was 67.4 ± 11.5 years old, and 51.9% were female. The mean duration of hypertension was 10.1 ± 6.4 years, with a mean systolic and diastolic blood pressure of 128.8 ± 12.3 and 72.9 ± 10.8 mmHg respectively. 40 out of 538 patients were found to have RHT, giving an overall prevalence of 7.43%. Four factors were found to be associated with increased risk of RHT, in ascending order of odds ratio: duration of hypertension (OR 1.08), male gender (OR 2.72), comorbid with type 2 diabetes mellitus (T2DM, OR 2.99), and congestive heart failure (CHF, OR 5.39). CONCLUSION: The prevalence of RHT among Chinese hypertensive patients in primary care setting of Hong Kong is 7.43%. RHT is more common in male patients, patients with longer duration of hypertension, concomitant T2DM and CHF. Clinicians should be vigilant when managing these groups of patients and provide aggressive treatment and close monitoring.

The cortical representation of language timescales is shared between reading and listening.

Language comprehension involves integrating low-level sensory inputs into a hierarchy of increasingly high-level features. Prior work studied brain representations of different levels of the language hierarchy, but has not determined whether these brain representations are shared between written and spoken language. To address this issue, we analyze fMRI BOLD data that were recorded while participants read and listened to the same narratives in each modality. Levels of the language hierarchy are operationalized as timescales, where each timescale refers to a set of spectral components of a language stimulus. Voxelwise encoding models are used to determine where different timescales are represented across the cerebral cortex, for each modality separately. These models reveal that between the two modalities timescale representations are organized similarly across the cortical surface. Our results suggest that, after low-level sensory processing, language integration proceeds similarly regardless of stimulus modality.

The Association of Pregnancy With Outcomes Among Critically Ill Reproductive-Aged Women: A Propensity Score-Matched Retrospective Cohort Analysis.

BACKGROUND: The maternal mortality rate in the United States is unacceptably high. However, the relative contribution of pregnancy to these outcomes is unknown. Studies comparing outcomes among pregnant vs nonpregnant critically ill patients show mixed results and are limited by small sample sizes. RESEARCH QUESTION: What is the association of pregnancy with critical illness outcomes? STUDY DESIGN AND METHODS: We performed a retrospective cohort study of women 18 to 55 years of age who received invasive mechanical ventilation (MV) on hospital day 0 or 1 or who demonstrated sepsis on admission (infection with organ failure) discharged from Premier Healthcare Database hospitals from 2008 through 2021. The exposure was pregnancy. The primary outcome was in-hospital mortality. We created propensity scores for pregnancy (using patient and hospital characteristics) and performed 1:1 propensity score matching without replacement within age strata (to ensure exact age matching). We performed multilevel multivariable mixed-effects logistic regression for propensity-matched pairs with pair as a random effect. RESULTS: Three thousand ninety-three pairs were included in the matched MV cohort, and 13,002 pairs were included in the sepsis cohort. The characteristics of both cohorts were well balanced (all standard mean differences, < 0.1). Among matched pairs, unadjusted mortality was 8.0% vs 13.8% for MV and 1.4% vs 2.3% for sepsis among pregnant and nonpregnant patients, respectively. In adjusted regression, pregnancy was associated with lower odds of in-hospital mortality (MV: OR, 0.50; 95% CI, 0.41-0.60; P < .001; sepsis: OR, 0.52; 95% CI, 0.40-0.67; P < .001). INTERPRETATION: In this large US cohort, critically ill pregnant women receiving MV or with sepsis showed better survival than propensity score-matched nonpregnant women. These findings must be interpreted in the context of likely residual confounding.

Aligning patient values and code status: Choice of Diction's Effect (CODE) study.

BACKGROUND: Decisions regarding resuscitation after cardiac arrest are critical from ethical, patient satisfaction, outcome, and healthcare cost standpoints. Physician-reported discussion barriers include topic discomfort, fear of time commitment, and difficulty articulating end-of-life concepts. The influence of language used in these discussions has not been tested. This study explored whether utilizing the alternate term "allow (a) natural death" changed code status decisions in hospitalized patients versus "do not resuscitate" (DNR). METHODS: All patients age 65 and over admitted to a general medicine hospital teaching service were screened (English-speaking, not ICU-level care, no active psychiatric illness, no substance misuse, no active DNR). Participants were randomized to resuscitation discussions with either DNR or "allow natural death" as the "no code" phrasing. Outcomes included patient resuscitation decision, satisfaction with and duration of the conversation, and decision correlation with illness severity and predicted resuscitation success. RESULTS: 102 participants were randomized to the "allow natural death" (N = 49) or DNR (N = 53) arms. The overall "no code" rate for our sample of hospitalized general medicine inpatients age >65 was 16.7%, with 13% in the DNR and 20.4% in the "allow natural death" arms (p = 0.35). Discussion length was similar in the DNR and "allow natural death" arms (3.9 + 3.2 vs. 4.9 + 3.9 minutes), and not significantly different (p = 0.53). Over 90% of participants were highly satisfied with their code status decision, without difference between arms (p = 0.49). CONCLUSIONS: Participants' code status discussions did not differ in "no code" rate between "allow natural death" and DNR arms but were short in length and had high patient satisfaction. Previously reported code status discussion barriers were not encountered. It is appropriate to screen code status in all hospitalized patients regardless of phrasing used.

An epidemic of cataract surgery in Korea: the effects of private health insurance on the National Health Insurance Service.

OBJECTIVES: In Korea, the National Health Insurance Service (NHIS) covers essential healthcare expenses, including cataract surgery. To address concerns that private health insurance (PHI) might have inflated the need for such procedures, we investigated the extent of the PHI-attributable increase in cataract surgery and its impact on NHIS-reimbursed expenses. METHODS: This retrospective, observational study uses nationwide claims data for cataract surgery from 2016 to 2020. We examined trends in utilization and cost, and we estimated the excess numbers of (1) cataract operations attributable to PHI and (2) types of intraocular lenses used for cataract surgery in 2020. RESULTS: Between 2016 and 2020, a 36.8% increase occurred in the number of cataract operations, with increases of 63.5% and 731.8% in the total healthcare costs reimbursed by NHIS and PHI, respectively. Over a 5-year period, the surgical rate per 100,000 people doubled for patients aged <65 years (from 328 in 2016 to 664 in 2020). Among the 619,771 cases in 2020 of cataract surgery reimbursed by the Korean diagnosis-related group system, more non-NHIS-covered intraocular lenses were used for patients aged <65 years than ≥65 years (68.1 vs. 14.2%). In 2020 alone, an estimated 129,311 excess operations occurred, accounting for an excess cost of US$115 million. CONCLUSIONS: A dramatic increase in the number and cost of cataract operations has occurred over the last 5 years. The PHI-related increase in operations resulted in increased costs to NHIS. Measures to curtail the non-indicated use of cataract surgery should be implemented regarding PHI.

Hypoventilation in patients with Prader-Willi syndrome across the pediatric age.

OBJECTIVES: Few data on alveolar hypoventilation in Prader-Willi syndrome (PWS) are available and the respiratory follow-up of these patients is not standardized. The objectives of this study were to evaluate the prevalence of alveolar hypoventilation in children with PWS and identify potential risk factors. STUDY DESIGN: This retrospective study included children with PWS recorded by polysomnography (PSG) with transcutaneous carbon dioxide pressure (PtcCO2) or end-tidal CO2 (ETCO2) measurements, between 2007 and 2021, in a tertiary hospital center. The primary outcome was the presence of alveolar hypoventilation defined as partial pressure of carbon dioxide (pCO2) ≥ 50 mmHg during ≥2% of total sleep time (TST) or more than five consecutive minutes. RESULTS: Among the 57 included children (38 boys, median age 4.8 years, range 0.1-15.6, 60% treated with growth hormone [GH], 37% obese), 19 (33%) had moderate-to-severe obstructive sleep apnea syndrome (defined as obstructive apnea-hypopnea index ≥5/h) and 20 (35%) had hypoventilation. The median (range) pCO2 max was 49 mmHg (38-69). Among the children with hypoventilation, 25% were asymptomatic. Median age and GH treatment were significantly higher in children with hypoventilation compared to those without. There was no significant difference in terms of sex, BMI, obstructive or central apnea-hypopnea index between both groups. CONCLUSION: The frequency of alveolar hypoventilation in children and adolescents with PWS is of concern and may increase with age and GH treatment. A regular screening by oximetry-capnography appears to be indicated whatever the sex, BMI, and rate of obstructive or central apneas.

Challenges to decarbonizing medication prescribing and use practices: A call to action.

Climate change undeniably impacts the social and environmental determinants of one's health. The healthcare sector, encompassing medications and the pharmaceutical industry supply chain, accounts for a significant portion of global health care contributions to greenhouse gas (GHG) and waste production. Despite these realities, healthcare professionals - physicians, pharmacists, nurses, and others - may be unaware of GHG emissions and the long-term environmental effects of the medications they prescribe, dispense, and administer daily. In this commentary, we identify existing challenges and explore potential strategies to recognize and reduce the climate change impacts associated with medication use.

Postoperative thrombotic events following major surgery in patients with a history of COVID-19: a retrospective cohort analysis of commercially insured beneficiaries in the USA.

PURPOSE: We sought to evaluate the synergistic risk of postoperative thrombosis in patients with a history of COVID-19 who undergo major surgery. Major surgery and SARS-CoV-2 infection are independently associated with an increased risk of thrombosis, but the magnitude of additional risk beyond surgery conferred by a COVID-19 history on the development of perioperative thrombotic events has not been clearly elucidated in the literature. METHODS: We conducted a retrospective cohort study among commercially insured adults in the USA from March 2020 to June 2021 using the Optum Labs Data Warehouse (OLDW), a longitudinal, real-world data asset containing deidentified administrative claims and electronic health records. We compared patients with prior COVID-19 who underwent surgery with control individuals who underwent surgery without a COVID-19 history and with control individuals who did not undergo surgery with and without a COVID-19 history. We assessed the interaction of surgery and previous COVID-19 on perioperative thrombotic events (venous thromboembolism and major adverse cardiovascular events) within 90 days using multivariable logistic regression and interaction analysis. RESULTS: Two million and two-hundred thousand eligible patients were identified from the OLDW. Patients in the surgical cohorts were older and more medically complex than nonsurgical population controls. After adjusting for confounders, only surgical exposure-not COVID-19 history-remained associated with perioperative thrombotic events (adjusted odds ratio [aOR], 4.07; 95% confidence interval [CI], 3.81 to 4.36). The multiplicative interaction term (aOR, 1.25; 95% CI, 0.96 to 1.61) and the synergy index (0.76; 95% CI, 0.56 to 1.04) suggest minimal effect modification of prior COVID-19 on surgery with regards to overall thrombotic risk. CONCLUSIONS: We found no evidence of synergistic thrombotic risk from previous COVID-19 in patients who underwent selected major surgery relative to the baseline thrombotic risk from surgery alone.

RéSUMé: OBJECTIF: Nous avons cherché à évaluer le risque synergique de thrombose postopératoire chez les patient·es ayant des antécédents de COVID-19 qui bénéficient d'une intervention chirurgicale majeure. La chirurgie majeure et l'infection par le SRAS-CoV-2 sont indépendamment associées à un risque accru de thrombose, mais l'ampleur du risque supplémentaire d'apparition de complications thrombotiques périopératoires, au-delà de la chirurgie et conféré par des antécédents de COVID-19, n'a pas été clairement élucidée dans la littérature. MéTHODE: Nous avons mené une étude de cohorte rétrospective auprès d'adultes assuré·es commercialement aux États-Unis de mars 2020 à juin 2021 à l'aide de la base de données Optum Labs Data Warehouse (OLDW), un actif de données longitudinales du monde réel contenant des requêtes administratives anonymisées et des dossiers de santé électroniques. Nous avons comparé les patient·es ayant déjà souffert de COVID-19 et ayant bénéficié d'une intervention chirurgicale avec des personnes témoins ayant bénéficié d'une intervention chirurgicale sans antécédents de COVID-19 et avec des personnes témoins n'ayant pas bénéficié de chirurgie, avec et sans antécédents de COVID-19. Nous avons évalué l'interaction de la chirurgie et des antécédents de COVID-19 avec les complications thrombotiques périopératoires (thromboembolie veineuse et événements cardiovasculaires indésirables majeurs) dans les 90 jours à l'aide d'une régression logistique multivariée et d'une analyse des interactions. RéSULTATS: Deux millions deux cent mille personnes admissibles ont été identifiées à partir du registre OLDW. Les patient·es des cohortes chirurgicales étaient plus âgé·es et présentaient une plus grande complexité médicale que les personnes témoins de la population non chirurgicale. Après ajustement pour tenir compte des facteurs de confusion, seule l'exposition chirurgicale ­ et non les antécédents de COVID-19 ­ est restée associée aux complications thrombotiques périopératoires (rapport de cotes ajusté [RCa], 4,07; intervalle de confiance [IC] à 95 %, 3,81 à 4,36). Le terme d'interaction multiplicative (RCa, 1,25; IC 95 %, 0,96 à 1,61) et l'indice de synergie (0,76; IC 95 %, 0,56 à 1,04) suggèrent une modification minimale de l'effet d'un diagnostic antérieur de COVID-19 sur la chirurgie en matière de risque thrombotique global. CONCLUSION: Nous n'avons trouvé aucune preuve de risque thrombotique synergique lié à une COVID-19 antérieure chez les patient·es ayant bénéficié d'une intervention chirurgicale par rapport au risque thrombotique de base lié à la chirurgie seule.

Management of pediatric renal trauma - Results from the American Association for Surgery and Trauma Multi-Institutional Pediatric Acute Renal Trauma Study (Mi-PARTS).

BACKGROUND: Pediatric renal trauma is rare and lacks sufficient population-specific data to generate evidence-based management guidelines. A non-operative approach is preferred and has been shown to be safe. However, bleeding risk assessment and management of collecting system injury is not well understood. We introduce the Multi-institutional Pediatric Acute Renal Trauma Study (Mi-PARTS), a retrospective cohort study designed to address these questions. This manuscript describes the demographics and contemporary management of pediatric renal trauma at Level I trauma centers in the United States. METHODS: Retrospective data were collected at 13 participating Level I trauma centers on pediatric patients presenting with renal trauma between 2010-2019. Data were gathered on demographics, injury characteristics, management, and short-term outcomes. Descriptive statistics were used to report on demographics, acute management and outcomes. RESULTS: In total 1216 cases were included in this study. 67.2% were male, and 93.8% had a blunt injury mechanism. 29.3% had isolated renal injuries. 65.6% were high-grade (AAST Grade III-V) injuries. The mean Injury Severity Score (ISS) was 20.5. Most patients were managed non-operatively (86.4%) 3.9% had an open surgical intervention, including 2.7% having nephrectomy. Angioembolization was performed in 0.9%. Collecting system intervention was performed in 7.9%. Overall mortality was 3.3% and was only observed in polytrauma. The rate of avoidable transfer was 28.2%. CONCLUSION: The management and outcomes of pediatric renal trauma lacks data to inform evidence-based guidelines. Non-operative management of bleeding following renal injury is a well-established practice. Intervention for renal trauma is rare. Our findings reinforce differences from the adult population, and highlights opportunities for further investigation. With data made available through Mi-PARTS we aim to answer pediatric specific questions, including a pediatric-specific bleeding risk nomogram, and better understanding indications for interventions for collecting system injuries. LEVEL OF EVIDENCE: IV, Epidemiological (prognostic/epidemiological, therapeutic/care management, diagnostic test/criteria, economic/value-based evaluations, and Systematic Review and Meta-Analysis).

Defining Pediatric Trauma Center Resource Utilization: Multidisciplinary Consensus-Based Criteria from the Pediatric Trauma Society.

BACKGROUND: Pediatric trauma triage and transfer decisions should incorporate the likelihood that an injured child will require pediatric trauma center (PTC) resources. Resource utilization may be a better basis than mortality risk when evaluating pediatric injury severity. However, there is currently no consensus definition of PTC resource utilization that encompasses the full scope of PTC services. METHODS: Consensus criteria were developed in collaboration with the Pediatric Trauma Society (PTS) Research Committee using a modified Delphi approach. An expert panel was recruited representing the following pediatric disciplines: prehospital care, emergency medicine, nursing, general surgery, neurosurgery, orthopedics, anesthesia, radiology, critical care, child abuse, and rehabilitation medicine. Resource utilization criteria were drafted from a comprehensive literature review, seeking to complete the following sentence: "Pediatric patients with traumatic injuries have used PTC resources if they..." Criteria were then refined and underwent three rounds of voting to achieve consensus. Consensus was defined as agreement of 75% or more panelists. Between the second and third voting rounds, broad feedback from attendees of the PTS annual meeting was obtained. RESULTS: The Delphi panel consisted of 18 members from 15 institutions. Twenty initial draft criteria were developed based on literature review. These criteria dealt with airway interventions, vascular access, initial stabilization procedures, fluid resuscitation, blood product transfusion, abdominal trauma/solid organ injury management, intensive care monitoring, anesthesia/sedation, advanced imaging, radiologic interpretation, child abuse evaluation, and rehabilitative services. After refinement and panel voting, 14 criteria achieved the >75% consensus threshold. The final consensus criteria were reviewed and endorsed by the PTS Guidelines Committee. CONCLUSIONS: This study defines multidisciplinary consensus-based criteria for PTC resource utilization. These criteria are an important step toward developing a gold standard, resource-based, pediatric injury severity metric. Such metrics can help optimize system-level pediatric trauma triage based on likelihood of requiring PTC resources. LEVEL OF EVIDENCE/STUDY TYPE: Level II, diagnostic test/criteria.

Generation of an Alagille syndrome (ALGS) patient-derived induced pluripotent stem cell line (TRNDi032-A) carrying a heterozygous mutation (p.Cys682Leufs*7) in the JAG1 gene.

Alagille syndrome (ALGS) is an autosomal dominant, multisystemic disorder due to haploinsufficiency in either the JAG1 gene (ALGS type 1) or the NOTCH2 gene (ALGS type 2). The disease has been difficult to diagnose and treat due to its muti-system clinical presentation, variable expressivity, and prenatal onset for some of the features. The generation of this iPSC line (TRNDi032-A) carrying a heterozygous mutation, p.Cys682Leufs*7 (c.2044dup), in the JAG1 gene provides a means of studying the disease and developing novel therapeutics towards patient treatment.

Minimum standard assessment of informed consent for internal medicine transition to residency program: A cohort study.

Background and Aims: Interns must be proficient in obtaining informed consent (IC), which is the Association of American Medical College's 11th of 13 Entrustable Professional Activities (EPAs). Medical students have limited opportunity to practice IC during clerkships, resulting in inconsistent proficiency. We aimed to create a tool to assess whether our transition to residency (TTR) workshop enables fourth-year medical students to meet a minimum standard of obtaining IC. Methods: Sixty fourth-year medical students were enrolled in the internal medicine virtual TTR course during AY2021. The curriculum prioritizes deliberate practice activities. Pre- and postworkshop assignments involved students typing verbatim what they would say during IC encounters. We modified an IC abstraction tool created by Spatz et al. to assess a minimum standard for students' IC assignments. Our final 7-item tool consisted of the following domains: "What," "Why," "How," "Benefits," "Quantitative Risks," "Qualitative Risks," and "Alternatives," weighing 1 point each. A minimum standard was obtained with a score of 6 or more points by appropriately discussing at least one domain involving risk and all other domains. Results: Students scored highly on the prework domains pertaining to "What," "Why," and "How" of the procedure with no significant difference on postwork. Significant improvement was achieved on postwork domains covering "Benefits" (p = 0.039) and "Alternatives" (p = 0.031). For domains involving "Qualitative" and "Quantitative Risks," there were no statistically significant improvements from pre- to postwork scores. Fifteen and 22 students met the minimum standard for IC on pre- and postwork, respectively. Conclusion: Our students demonstrated a good a priori understanding of the "What," "Why," and "How" domains. After the workshop, they more reliably discussed "Benefits" and "Alternatives." Our abstraction tool helped assess the strengths and weaknesses in our students' IC skillset and helped recognize areas of our curriculum that will benefit from improvements to bring students to meet the minimum standard.

Host heparan sulfate promotes ACE2 super-cluster assembly and enhances SARS-CoV-2-associated syncytium formation.

SARS-CoV-2 infection causes spike-dependent fusion of infected cells with ACE2 positive neighboring cells, generating multi-nuclear syncytia that are often associated with severe COVID. To better elucidate the mechanism of spike-induced syncytium formation, we combine chemical genetics with 4D confocal imaging to establish the cell surface heparan sulfate (HS) as a critical stimulator for spike-induced cell-cell fusion. We show that HS binds spike and promotes spike-induced ACE2 clustering, forming synapse-like cell-cell contacts that facilitate fusion pore formation between ACE2-expresing and spike-transfected human cells. Chemical or genetic inhibition of HS mitigates ACE2 clustering, and thus, syncytium formation, whereas in a cell-free system comprising purified HS and lipid-anchored ACE2, HS stimulates ACE2 clustering directly in the presence of spike. Furthermore, HS-stimulated syncytium formation and receptor clustering require a conserved ACE2 linker distal from the spike-binding site. Importantly, the cell fusion-boosting function of HS can be targeted by an investigational HS-binding drug, which reduces syncytium formation in vitro and viral infection in mice. Thus, HS, as a host factor exploited by SARS-CoV-2 to facilitate receptor clustering and a stimulator of infection-associated syncytium formation, may be a promising therapeutic target for severe COVID.

Availability of living donor optimizes timing of liver transplant in high-risk waitlisted cirrhosis patients.

Liver transplant (LT) candidates have become older and frailer, with growing Non-alcoholic steatohepatitis (NASH) and comorbid disease burden in recent years, predisposing them for poor waitlist outcomes. We aimed to evaluate the impact of access to living donor liver transplantation (LDLT) in waitlisted patients at highest risk of dropout. We reviewed all adult patients with decompensated cirrhosis listed for LT from November 2012 to December 2018. Patients with a potential living donor (pLD) available were identified. Survival analyses with Cox Proportional Hazards models and time to LT with Competing risk models were performed followed by prediction model development. Out of 860 patients who met inclusion criteria, 360 (41.8%) had a pLD identified and 496 (57.6%) underwent LT, out of which 170 (34.2%) were LDLT. The benefit of pLD was evident for all, but patients with moderate to severe frailty at listing (interaction p = 0.03), height <160 cm (interaction p = 0.03), and Model for end stage liver disease (MELD)-Na score <20 (interaction p < 0.0001) especially benefited. Our prediction model identified patients at highest risk of dropout while waiting for deceased donor and most benefiting of pLD (time-dependent area under the receiver operating characteristic curve 0.82). Access to LDLT in a transplant program can optimize the timing of transplant for the increasingly older, frail patient population with comorbidities who are at highest risk of dropout.

Development of a Radiomics-Based Model to Predict Graft Fibrosis in Liver Transplant Recipients: A Pilot Study.

Liver Transplantation is complicated by recurrent fibrosis in 40% of recipients. We evaluated the ability of clinical and radiomic features to flag patients at risk of developing future graft fibrosis. CT scans of 254 patients at 3-6 months post-liver transplant were retrospectively analyzed. Volumetric radiomic features were extracted from the portal phase using an Artificial Intelligence-based tool (PyRadiomics). The primary endpoint was clinically significant (≥F2) graft fibrosis. A 10-fold cross-validated LASSO model using clinical and radiomic features was developed. In total, 75 patients (29.5%) developed ≥F2 fibrosis by a median of 19 (4.3-121.8) months. The maximum liver attenuation at the venous phase (a radiomic feature reflecting venous perfusion), primary etiology, donor/recipient age, recurrence of disease, brain-dead donor, tacrolimus use at 3 months, and APRI score at 3 months were predictive of ≥F2 fibrosis. The combination of radiomics and the clinical features increased the AUC to 0.811 from 0.793 for the clinical-only model (p = 0.008) and from 0.664 for the radiomics-only model (p < 0.001) to predict future ≥F2 fibrosis. This pilot study exploring the role of radiomics demonstrates that the addition of radiomic features in a clinical model increased the model's performance. Further studies are required to investigate the generalizability of this experimental tool.

A Protocol for Culture and Characterization of Human Induced Pluripotent Stem Cells After Induction.

Human induced pluripotent stem cells (hiPSCs) are characterized by unlimited self-renewal and the capability to differentiate into all three germ layers, with the potential to further differentiate into all types of cells and tissues. Human iPSCs retain all genetic information from their original donors and can be developed into disease models to study disease pathophysiology, identify disease phenotypes and biomarkers, and evaluate therapeutic efficacy and toxicity for drug development. Human iPSCs can also be used to develop cell therapies and regenerative medicine. In the last decade, the technologies for hiPSC generation and differentiation have advanced rapidly. Human iPSC culture and propagation are tedious and require careful handling. High-quality hiPSCs are necessary for downstream applications. The methods, techniques, and skills for hiPSC maintenance and characterization are very different from those for immortalized cell lines. It can be a challenge for new laboratory staff, and sometimes even for experienced staff, to properly culture and maintain the high quality of these cells. Here, we describe a comprehensive set of protocols for hiPSC propagation under chemically defined and feeder-free culture conditions. These step-by-step protocols describe in detail all the reagents and experimental procedures needed to culture hiPSCs. The protocols also describe experimental methods for hiPSC characterization, including immunofluorescence staining and flow cytometric analysis with a panel of pluripotency markers, a teratoma formation assay for validation of in vivo pluripotency, and detection of Sendai virus to ensure elimination of the viral vectors. These protocols have been successfully used in our laboratory for hiPSC expansion and propagation, and this article provide a useful reference guide for laboratory staff to work on hiPSC culture. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Propagation and cryopreservation of hiPSC cultures Basic Protocol 2: Recovery of cryopreserved hiPSCs Basic Protocol 3: Validation of pluripotency markers via immunocytochemical analysis Alternate Protocol: Determination of the expression of pluripotency markers via flow cytometry analysis Basic Protocol 4: Assessment of pluripotency via in vivo teratoma formation assay Basic Protocol 5: Confirmation of Sendai viral vector clearance via RT-PCR.