Systematic dissection of tumor-normal single-cell ecosystems across a thousand tumors of 30 cancer types.

The complexity of the tumor microenvironment poses significant challenges in cancer therapy. Here, to comprehensively investigate the tumor-normal ecosystems, we perform an integrative analysis of 4.9 million single-cell transcriptomes from 1070 tumor and 493 normal samples in combination with pan-cancer 137 spatial transcriptomics, 8887 TCGA, and 1261 checkpoint inhibitor-treated bulk tumors. We define a myriad of cell states constituting the tumor-normal ecosystems and also identify hallmark gene signatures across different cell types and organs. Our atlas characterizes distinctions between inflammatory fibroblasts marked by AKR1C1 or WNT5A in terms of cellular interactions and spatial co-localization patterns. Co-occurrence analysis reveals interferon-enriched community states including tertiary lymphoid structure (TLS) components, which exhibit differential rewiring between tumor, adjacent normal, and healthy normal tissues. The favorable response of interferon-enriched community states to immunotherapy is validated using immunotherapy-treated cancers (n = 1261) including our lung cancer cohort (n = 497). Deconvolution of spatial transcriptomes discriminates TLS-enriched from non-enriched cell types among immunotherapy-favorable components. Our systematic dissection of tumor-normal ecosystems provides a deeper understanding of inter- and intra-tumoral heterogeneity.

Status and perception of point-of-care ultrasound education in Korean medical schools: A national cross-sectional study.

As point-of-care ultrasound (POCUS) is increasingly being used in clinical settings, ultrasound education is expanding into student curricula. We aimed to determine the status and awareness of POCUS education in Korean medical schools using a nationwide cross-sectional survey. In October 2021, a survey questionnaire consisting of 20 questions was distributed via e-mail to professors in the emergency medicine (EM) departments of Korean medical schools. The questionnaire encompassed 19 multiple-choice questions covering demographics, current education, perceptions, and barriers, and the final question was an open-ended inquiry seeking suggestions for POCUS education. All EM departments of the 40 medical schools responded, of which only 13 (33%) reported providing POCUS education. The implementation of POCUS education primarily occurred in the third and fourth years, with less than 4 hours of dedicated training time. Five schools offered a hands-on education. Among schools offering ultrasound education, POCUS training for trauma cases is the most common. Eight schools had designated professors responsible for POCUS education and only 2 possessed educational ultrasound devices. Of the respondents, 64% expressed the belief that POCUS education for medical students is necessary, whereas 36%, including those with neutral opinions, did not anticipate its importance. The identified barriers to POCUS education included faculty shortages (83%), infrastructure limitations (76%), training time constraints (74%), and a limited awareness of POCUS (29%). POCUS education in Korean medical schools was limited to a minority of EM departments (33%). To successfully implement POCUS education in medical curricula, it is crucial to clarify learning objectives, enhance faculty recognition, and improve the infrastructure. These findings provide valuable insights for advancing ultrasound training in medical schools to ensure the provision of high-quality POCUS education for future healthcare professionals.

Hippo-YAP/TAZ signalling coordinates adipose plasticity and energy balance by uncoupling leptin expression from fat mass.

Adipose tissues serve as an energy reservoir and endocrine organ, yet the mechanisms that coordinate these functions remain elusive. Here, we show that the transcriptional coregulators, YAP and TAZ, uncouple fat mass from leptin levels and regulate adipocyte plasticity to maintain metabolic homeostasis. Activating YAP/TAZ signalling in adipocytes by deletion of the upstream regulators Lats1 and Lats2 results in a profound reduction in fat mass by converting mature adipocytes into delipidated progenitor-like cells, but does not cause lipodystrophy-related metabolic dysfunction, due to a paradoxical increase in circulating leptin levels. Mechanistically, we demonstrate that YAP/TAZ-TEAD signalling upregulates leptin expression by directly binding to an upstream enhancer site of the leptin gene. We further show that YAP/TAZ activity is associated with, and functionally required for, leptin regulation during fasting and refeeding. These results suggest that adipocyte Hippo-YAP/TAZ signalling constitutes a nexus for coordinating adipose tissue lipid storage capacity and systemic energy balance through the regulation of adipocyte plasticity and leptin gene transcription.

scLENS: data-driven signal detection for unbiased scRNA-seq data analysis.

High dimensionality and noise have limited the new biological insights that can be discovered in scRNA-seq data. While dimensionality reduction tools have been developed to extract biological signals from the data, they often require manual determination of signal dimension, introducing user bias. Furthermore, a common data preprocessing method, log normalization, can unintentionally distort signals in the data. Here, we develop scLENS, a dimensionality reduction tool that circumvents the long-standing issues of signal distortion and manual input. Specifically, we identify the primary cause of signal distortion during log normalization and effectively address it by uniformizing cell vector lengths with L2 normalization. Furthermore, we utilize random matrix theory-based noise filtering and a signal robustness test to enable data-driven determination of the threshold for signal dimensions. Our method outperforms 11 widely used dimensionality reduction tools and performs particularly well for challenging scRNA-seq datasets with high sparsity and variability. To facilitate the use of scLENS, we provide a user-friendly package that automates accurate signal detection of scRNA-seq data without manual time-consuming tuning.

Inflammatory response in dairy cows caused by heat stress and biological mechanisms for maintaining homeostasis.

Climate change increases global temperatures, which is lethal to both livestock and humans. Heat stress is known as one of the various livestock stresses, and dairy cows react sensitively to high-temperature stress. We aimed to better understand the effects of heat stress on the health of dairy cows and observing biological changes. Individual cows were divided into normal (21-22 °C, 50-60% humidity) and high temperature (31-32 °C, 80-95% humidity), respectively, for 7-days. We performed metabolomic and transcriptome analyses of the blood and gut microbiomes of feces. In the high-temperature group, nine metabolites including linoleic acid and fructose were downregulated, and 154 upregulated and 72 downregulated DEGs (Differentially Expressed Genes) were identified, and eighteen microbes including Intestinimonas and Pseudoflavonifractor in genus level were significantly different from normal group. Linoleic acid and fructose have confirmed that associated with various stresses, and functional analysis of DEG and microorganisms showing significant differences confirmed that high-temperature stress is related to the inflammatory response, immune system, cellular energy mechanism, and microbial butyrate production. These biological changes were likely to withstand high-temperature stress. Immune and inflammatory responses are known to be induced by heat stress, which has been identified to maintain homeostasis through modulation at metabolome, transcriptome and microbiome levels. In these findings, heat stress condition can trigger alteration of immune system and cellular energy metabolism, which is shown as reduced metabolites, pathway enrichment and differential microbes. As results of this study did not include direct phenotypic data, we believe that additional validation is required in the future. In conclusion, high-temperature stress contributed to the reduction of metabolites, changes in gene expression patterns and composition of gut microbiota, which are thought to support dairy cows in withstanding high-temperature stress via modulating immune-related genes, and cellular energy metabolism to maintain homeostasis.

No Significant Differences in Presepsin Levels According to the Causative Microorganism of Bloodstream Infection.

BACKGROUND: CD14 recognizes lipopolysaccharide (LPS), and presepsin is a fragment of soluble CD14. Still, it remains uncertain whether Gram-negative bacteria induce higher presepsin levels than other microorganisms. To address this question, this study aimed to analyze presepsin levels based on microorganisms isolated in blood cultures. MATERIALS AND METHODS: This study was a single-center study comprising suspected sepsis patients enrolled from July 2020 to September 2020. A total of 95 patients with a single isolate confirmed in blood culture were analyzed to evaluate if there are any differences in presepsin levels according to microbial isolates. Plasma presepsin level was measured using PATHFAST assay kit and analyzer (LSI Medience Corporation, Tokyo, Japan). RESULTS: There were 26 Gram-positive bacteremia, 65 Gram-negative bacteremia, and 3 fungemia patients with median presepsin levels of 869, 1,439, and 11,951 pg/mL, respectively. Besides, one case of algaemia demonstrated a presepsin level of 1,231 pg/mL. Our results showed no statistically significant difference in presepsin levels among patients with Gram-positive bacteremia, Gram-negative bacteremia, and fungemia. Furthermore, presepsin levels did not differ significantly among bloodstream infections caused by bacteria that were isolated from at least three different patients. In particular, Gram-positive bacteria such as Staphylococcus aureus and Enterococcus faecalis were able to induce presepsin levels comparable to those induced by Gram-negative bacteria. CONCLUSION: We demonstrated that there were no significant differences in plasma presepsin levels according to microbial isolates in blood culture. The major cause of the variability in presepsin levels during bloodstream infection might be the immunogenicity of each microorganism rather than the presence of LPS in the microorganism.

Integrative analysis of spatial and single-cell transcriptome data from human pancreatic cancer reveals an intermediate cancer cell population associated with poor prognosis.

BACKGROUND: Recent studies using single-cell transcriptomic analysis have reported several distinct clusters of neoplastic epithelial cells and cancer-associated fibroblasts in the pancreatic cancer tumor microenvironment. However, their molecular characteristics and biological significance have not been clearly elucidated due to intra- and inter-tumoral heterogeneity. METHODS: We performed single-cell RNA sequencing using enriched non-immune cell populations from 17 pancreatic tumor tissues (16 pancreatic cancer and one high-grade dysplasia) and generated paired spatial transcriptomic data from seven patient samples. RESULTS: We identified five distinct functional subclusters of pancreatic cancer cells and six distinct cancer-associated fibroblast subclusters. We deeply profiled their characteristics, and we found that these subclusters successfully deconvoluted most of the features suggested in bulk transcriptome analysis of pancreatic cancer. Among those subclusters, we identified a novel cancer cell subcluster, Ep_VGLL1, showing intermediate characteristics between the extremities of basal-like and classical dichotomy, despite its prognostic value. Molecular features of Ep_VGLL1 suggest its transitional properties between basal-like and classical subtypes, which is supported by spatial transcriptomic data. CONCLUSIONS: This integrative analysis not only provides a comprehensive landscape of pancreatic cancer and fibroblast population, but also suggests a novel insight to the dynamic states of pancreatic cancer cells and unveils potential therapeutic targets.

Real-Time Tracheal Ultrasound vs. Capnography for Intubation Confirmation during CPR Wearing a Powered Air-Purifying Respirator in COVID-19 Era.

This study aimed to compare the accuracy of real-time trans-tracheal ultrasound (TTUS) with capnography to confirm intubation in cardiopulmonary resuscitation (CPR) while wearing a powered air-purifying respirator (PAPR). This setting reflects increased caution due to contagious diseases. This single-center, prospective, comparative study enrolled patients requiring CPR while wearing a PAPR who visited the emergency department of a tertiary medical center from December 2020 to August 2022. A physician performed the TTUS in real time and recorded the tube placement assessment. Another healthcare provider attached waveform capnography to the tube and recorded end-tidal carbon dioxide (EtCO2) after five ventilations. The accuracy and agreement of both methods compared with direct laryngoscopic visualization of tube placement, and the time taken by both methods was evaluated. Thirty-three patients with cardiac arrest were analyzed. TTUS confirmed tube placement with 100% accuracy, sensitivity, and specificity, whereas capnography demonstrated 97% accuracy, 96.8% sensitivity, and 100% specificity. The Kappa values for TTUS and capnography compared to direct visualization were 1.0 and 0.7843, respectively. EtCO2 was measured in 45 (37-59) seconds (median (interquartile range)), whereas TTUS required only 12 (8-23) seconds, indicating that TTUS was significantly faster (p < 0.001). No significant correlation was found between the physician's TTUS proficiency and image acquisition time. This study demonstrated that TTUS is more accurate and faster than EtCO2 measurement for confirming endotracheal tube placement during CPR, particularly in the context of PAPR usage in pandemic conditions.

Carrier frequency and incidence of alpha-mannosidosis: population database-based study-focus on the East Asian and Korean population.

Background: Alpha-mannosidosis caused by mutations in the MAN2B1 gene is a rare genetic disorder characterized by physical abnormalities and intellectual disabilities. The objective of this study was to analyze the carrier frequency and estimated incidence of alpha-mannosidosis in East Asian populations, as limited data exists on its incidence in this group. Methods: In this study, a total of 125,748 exomes from the gnomAD database was analyzed. Additionally, 5,305 data from the KOVA and 1,722 data from the KRGDB, both representing Korean populations, were included. Results: The global carrier frequency of alpha-mannosidosis in gnomAD was 0.23%; the highest carrier frequency was observed in the Finnish at 0.49%, and East Asians had the second highest carrier frequency at 0.30%. Globally, the approximate incidence of alpha-mannosidosis was calculated at 1 in 784,535, l in 166,801 Europeans (Finnish), and l in 431,689 East Asians. By integrating the data from the 8,936 Koreans in gnomAD Korean, KOVA and KRGDB, the carrier frequency of alpha-mannosidosis in the Korean population was 0.04% and estimated incidence was 1 in 19,963,024. Conclusion: This study is the first to investigate the carrier frequencies of alpha-mannosidosis in East Asians and Koreans, including specific subpopulations, utilizing gnomAD and the Korean genomic database. The variant spectrum of MAN2B1 genes in East Asians showed significant differences compared to other ethnic groups. Our data provide valuable reference information for future investigations into alpha-mannosidosis, aiding in understanding the genetic diversity and specific variants associated with the condition in East Asian populations.

Associations of Healthy Eating Behavior with Mental Health and Health-Related Quality of Life: Results from the Korean National Representative Survey.

BACKGROUND: Healthy eating behaviors may be related to mental health and health-related quality of life. This study investigates the associations between diet quality, mental health, and health-related quality of life among men and women in Korea. METHODS: A total of 6823 participants, aged 19, from the 7th Korea National Health and Nutrition Examination Survey from 2016 to 2018 were included. Their overall diet quality was estimated using the Korean Healthy Eating Index (KHEI). Multivariate logistic regression was used to identify the associations between diet quality, mental health, and quality of life. RESULTS: The prevalence of stress perception and depression was highest in the lowest tertile of the KHEI score and higher for women than men. Among men, a significant association was observed only for stress perception and depressive symptoms in the second tertile, with odds ratios of 0.745 (95% CI, 0.585-0.949) and 0.519 (95% CI, 0.275-0.980). In contrast, the multivariate-adjusted odds ratios for stress perception, depressive symptoms, and low EQ-5D index among women in the highest tertile were 0.668 (95% CI, 0.541-0.823), 0.464 (95% CI, 0.288-0.746), and 0.722 (95% CI, 0.566-0.920), and significant dose-response associations were observed. CONCLUSIONS: A higher-quality diet was associated with a lower risk of stress and depression and a better quality of life. Thus, healthy eating behaviors may improve mental health and quality of life.

Effect of Blade Size on the First-Pass Success Rate of Endotracheal Intubation Using the C-MAC Video Laryngoscope.

We sought to determine whether blade size influences the first-pass success (FPS) rate when performing endotracheal intubation (ETI) with a C-MAC video laryngoscope (VL) in emergency department (ED) patients. This single-center, retrospective, observational study was conducted between August 2016 and July 2022. A total of 1467 patients was divided into two categories based on the blade size used during the first ETI attempt: blade-3 (n = 365) and blade-4 groups (n = 1102). The primary outcome was the FPS rate. The secondary outcomes included the glottic view, multiple attempt rate, and ETI-related complications. We used propensity score matching to reduce the potential confounders between the two groups. Among these, 363 pairs of matched propensity scores were generated. The FPS rate did not differ between the blade-3 (84.8%) and blade-4 groups (87.3%) in the matched cohort (p = 0.335). The multiple attempt rate did not differ significantly between groups (p = 0.289) and was 3.9% and 2.5% in the blade-3 and blade-4 groups, respectively. The difficult glottic view (11.3 vs. 6.9%, p = 0.039) and complication rates (15.4% vs. 10.5%, p = 0.047) were significantly higher in the blade-3 group than in the blade-4 group. The FPS rates of ETI with the blade-3 and blade-4 groups in adult patients in the ED did not differ significantly.

Prognostic Performance of Sequential Organ Failure Assessment, Acute Physiology and Chronic Health Evaluation III, and Simplified Acute Physiology Score II Scores in Patients with Suspected Infection According to Intensive Care Unit Type.

We investigated the prognostic performance of scoring systems by the intensive care unit (ICU) type. This was a retrospective observational study using data from the Marketplace for Medical Information in the Intensive Care IV database. The primary outcome was in-hospital mortality. We obtained Sequential Organ Failure Assessment (SOFA), Acute Physiology and Chronic Health Evaluation (APACHE) III, and Simplified Acute Physiology Score (SAPS) II scores in each ICU type. Prognostic performance was evaluated with the area under the receiver operating characteristic curve (AUROC) and was compared among ICU types. A total of 29,618 patients were analyzed, and the in-hospital mortality was 12.4%. The overall prognostic performance of APACHE III was significantly higher than those of SOFA and SAPS II (0.807, [95% confidence interval, 0.799-0.814], 0.785 [0.773-0.797], and 0.795 [0.787-0.811], respectively). The prognostic performance of SOFA, APACHE III, and SAPS II scores was significantly different between ICU types. The AUROC ranges of SOFA, APACHE III, and SAPS II were 0.723-0.826, 0.728-0.860, and 0.759-0.819, respectively. The neurosurgical and surgical ICUs had lower prognostic performance than other ICU types. The prognostic performance of scoring systems in patients with suspected infection is significantly different according to ICU type. APACHE III systems have the highest prediction performance. ICU type may be a significant factor in the prognostication.

Prognostic accuracy of initial and 24-h maximum SOFA scores of septic shock patients in the emergency department.

Background: We compared the prognostic accuracy of in-hospital mortality of the initial Sequential Organ Failure Assessment (SOFAini) score at the time of sepsis recognition and resuscitation and the maximum SOFA score (SOFAmax) using the worst variables in the 24 h after the initial score measurement in emergency department (ED) patients with septic shock. Methods: This was a retrospective observational study using a multicenter prospective registry of septic shock patients in the ED between October 2015 and December 2019. The primary outcome was in-hospital mortality. The prognostic accuracies of SOFAini and SOFAmax were evaluated using the area under the receiver operating characteristic (AUC) curve. Results: A total of 4860 patients was included, and the in-hospital mortality was 22.1%. In 59.7% of patients, SOFAmax increased compared with SOFAini, and the mean change of total SOFA score was 2.0 (standard deviation, 2.3). There was a significant difference in in-hospital mortality according to total SOFA score and the SOFA component scores, except cardiovascular SOFA score. The AUC of SOFAmax (0.71; 95% confidence interval [CI], 0.69-0.72) was significantly higher than that of SOFAini (AUC, 0.67; 95% CI, 0.66-0.69) in predicting in-hospital mortality. The AUCs of all scores of the six components were higher for the maximum values. Conclusion: The prognostic accuracy of the initial SOFA score at the time of sepsis recognition was lower than the 24-h maximal SOFA score in ED patients with septic shock. Follow-up assessments of organ failure may improve discrimination of the SOFA score for predicting mortality.

Distinct features of B cell receptors in neuromyelitis optica spectrum disorder among CNS inflammatory demyelinating diseases.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) stands out among CNS inflammatory demyelinating diseases (CIDDs) due to its unique disease characteristics, including severe clinical attacks with extensive lesions and its association with systemic autoimmune diseases. We aimed to investigate whether characteristics of B cell receptors (BCRs) differ between NMOSD and other CIDDs using high-throughput sequencing. METHODS: From a prospective cohort, we recruited patients with CIDDs and categorized them based on the presence and type of autoantibodies: NMOSD with anti-aquaporin-4 antibodies, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) with anti-myelin oligodendrocyte glycoprotein antibodies, double-seronegative demyelinating disease (DSN), and healthy controls (HCs). The BCR features, including isotype class, clonality, somatic hypermutation (SHM), and the third complementarity-determining region (CDR3) length, were analyzed and compared among the different disease groups. RESULTS: Blood samples from 33 patients with CIDDs (13 NMOSD, 12 MOGAD, and 8 DSN) and 34 HCs were investigated for BCR sequencing. Patients with NMOSD tended to have more activated BCR features compare to the other disease groups. They showed a lower proportion of unswitched isotypes (IgM and IgD) and a higher proportion of switched isotypes (IgG), increased clonality of BCRs, higher rates of SHM, and shorter lengths of CDR3. Notably, advanced age was identified as a clinical factor associated with these activated BCR features, including increased levels of clonality and SHM rates in the NMOSD group. Conversely, no such clinical factors were found to be associated with activated BCR features in the other CIDD groups. CONCLUSIONS: NMOSD patients, among those with CIDDs, displayed the most pronounced B cell activation, characterized by higher levels of isotype class switching, clonality, SHM rates, and shorter CDR3 lengths. These findings suggest that B cell-mediated humoral immune responses and characteristics in NMOSD patients are distinct from those observed in the other CIDDs, including MOGAD. Age was identified as a clinical factor associated with BCR activation specifically in NMOSD, implying the significance of persistent B cell activation attributed to anti-aquaporin-4 antibodies, even in the absence of clinical relapses throughout an individual's lifetime.

Acoustofluidic lysis of cancer cells and Raman spectrum profiling.

The lysis of cancer cells inside a sessile droplet was performed using traveling surface acoustic waves (SAWs) without any chemical reagents. Raman spectrum profiling was then carried out to explore detailed cell-derived data. The Rayleigh waves formed by an interdigital transducer were made to propagate along the surface of an LiNbO3 substrate. Polystyrene microparticles (PSMPs) were used to establish mechanical cell lysis effectively, and gold nanoparticles (AuNPs) were added to enhance the Raman signals from the lysed cells by SAWs. The lysis efficiency was evaluated according to the size and concentration of the PSMPs in experiments where the frequency was varied. Lysis occurred mainly by mechanical collision using PSMPs in a high-frequency domain, and the lysis efficiency was improved by increasing the application time and the energy density of the SAWs. Raman signals from the lysed cells were greatly enhanced by nanogaps formed by the AuNPs, which were evenly distributed irrespective of the SAWs through the frequency-independent behavior of the AuNPs. Finally, detailed Raman spectra of MDA-MB-231, malignant breast cancer cells, were acquired, and various organic matter-derived peaks were observed. The 95% confidence region for cells subjected to lysis was more widely distributed than that of cells not subjected to lysis. The proposed SAW platform is expected to facilitate the detection of small quantities and to be applied in biomedical applications.

Yolk sac cell atlas reveals multiorgan functions during human early development.

The extraembryonic yolk sac (YS) ensures delivery of nutritional support and oxygen to the developing embryo but remains ill-defined in humans. We therefore assembled a comprehensive multiomic reference of the human YS from 3 to 8 postconception weeks by integrating single-cell protein and gene expression data. Beyond its recognized role as a site of hematopoiesis, we highlight roles in metabolism, coagulation, vascular development, and hematopoietic regulation. We reconstructed the emergence and decline of YS hematopoietic stem and progenitor cells from hemogenic endothelium and revealed a YS-specific accelerated route to macrophage production that seeds developing organs. The multiorgan functions of the YS are superseded as intraembryonic organs develop, effecting a multifaceted relay of vital functions as pregnancy proceeds.

Growing disparity in the prevalence of chronic obstructive pulmonary disease between people with and without disabilities: a Korean nationwide serial cross-sectional study.

Few studies have examined the association between disability and chronic obstructive pulmonary disease (COPD). We compared the trends in the annual COPD prevalence between people with and without disabilities, and examined the association between disability and COPD. We linked the National Health Information Database (2008-2017) with the National Disability Registration Database, which includes more than 2 million people with disabilities every year. In the 2017 dataset, people with disabilities had a higher prevalence of COPD than those without disabilities (30.6% vs. 12.5%, P < 0.001). The age-standardized prevalence rate of COPD among people without disabilities increased from 4.2 in 2008 to 10.9% in 2017 (change of 6.7%), whereas that among those with disabilities increased from 7.0 to 17.1% (change of 10.1%). In multivariate analysis, compared to people without disabilities, those with disabilities had a higher probability of having COPD (adjusted odds ratio, 1.42; 95% confidence interval 1.42-1.43). The results of subgroup analysis by disability characteristics suggested that disabilities due to failure of an organ, such as the kidney, lung, heart, or liver, and severe disabilities were particularly vulnerable to COPD. In conclusion, people with disabilities are more likely to have COPD compared to people without disabilities. Further longitudinal studies that examine cause-and-effect relationship between disability and COPD are needed to clarify this relationship and to further investigate any potential negative effects associated with the coexistence of these conditions.

Development and derivation of bacteremia prediction model in patients with hepatobiliary infection.

INTRODUCTION: Hepatobiliary infections are common in the emergency department (ED), and the mortality rate for this condition is high. A suitable bacteremia prediction model would support prompt identification of bacteremia and appropriate management of hepatobiliary infections in the ED. Therefore, we attempted to produce a bacteremia prediction model with both internal and external validation for hepatobiliary infections in the ED. METHODS: Patients with hepatobiliary infection were extracted from retrospective cohort databases of two tertiary hospitals from January 2018 to December 2019 and from January 2016 to December 2019, respectively. Independent risk factors were determined using multivariable logistic regression in a developmental cohort. We assigned a weighted value to predictive factors and developed a prediction model, which was validated both internally and externally. We assessed discrimination using the area under the receiver operating characteristics curve (AUC). RESULTS: One hospital cohort of 1568 patients was randomly divided into a developmental group of 927 patients (60%) and an internal validation group of 641 patients (40%), and 736 people from the other hospital cohort were used for external validation. Bacteremia rates were 20.5%, 18.1%, and 23.1% in the developmental, internal, and external validation cohorts, respectively. Nine significant factors were used for predicting bacteremia, including age, three vital signs, and five laboratory tests. After applying our bacteremia prediction rule to the validation cohort, 56.5% and 53.8% of the internal and external validation groups were classified as low-risk bacteremia groups (bacteremia rates: 8.6% and 13.9%, respectively). The AUCs were 0.727 (95% confidence interval [CI]: 0.686-0.767), 0.730 (95% CI: 0.679-0.781), and 0.715 (95% CI: 0.672-0.758) for the developmental, internal, and external validation cohorts, respectively. The sensitivity and specificity for internal validation/external validation was 73.2%/67.6% and 63.0%/60.2%, respectively. CONCLUSION: A bacteremia prediction model for hepatobiliary infection might be useful to predict the risk of bacteremia. It might also reduce the need for blood culture in low-risk patients.

AXL+SIGLEC6+ dendritic cells in cerebrospinal fluid and brain tissues of patients with autoimmune inflammatory demyelinating disease of CNS.

Inflammatory demyelinating disease of the CNS (IDD) is a heterogeneous group of autoimmune diseases, and multiple sclerosis is the most common type. Dendritic cells (DCs), major antigen-presenting cells, have been proposed to play a central role in the pathogenesis of IDD. The AXL+SIGLEC6+ DC (ASDC) has been only recently identified in humans and has a high capability of T cell activation. Nevertheless, its contribution to CNS autoimmunity remains still obscure. Here, we aimed to identify the ASDC in diverse sample types from IDD patients and experimental autoimmune encephalomyelitis (EAE). A detailed analysis of DC subpopulations using single-cell transcriptomics for the paired cerebrospinal fluid (CSF) and blood samples of IDD patients (total n = 9) revealed that three subtypes of DCs (ASDCs, ACY3+ DCs, and LAMP3+ DCs) were overrepresented in CSF compared with their paired blood. Among these DCs, ASDCs were also more abundant in CSF of IDD patients than in controls, manifesting poly-adhesional and stimulatory characteristics. In the brain biopsied tissues of IDD patients, obtained at the acute attack of disease, ASDC were also frequently found in close contact with T cells. Lastly, the frequency of ASDC was found to be temporally more abundant in acute attack of disease both in CSF samples of IDD patients and in tissues of EAE, an animal model for CNS autoimmunity. Our analysis suggests that the ASDC might be involved in the pathogenesis of CNS autoimmunity.