Fluoride induces pyroptosis via IL-17A-mediated caspase-1/11-dependent pathways and Bifidobacterium intervention in testis

Fluoride, a ubiquitous environmental pollutant, poses a significant public health threat. Our previous study revealed a correlation between fluoride-induced testicular pyroptosis and male reproductive dysfunction. However, the underlying mechanism remains unclear. Wild-type and interleukin 17A knockout mice were exposed to sodium fluoride (100 mg/L) in deionized drinking water for 18 weeks. Bifidobacterium intervention (1 × 109 CFU/mL, 0.2 mL/day, administered via gavage) commenced in the 10th week. Sperm quality, testicular morphology, key pyroptosis markers, spermatogenesis key genes, IL-17A signaling pathway, and pyroptosis pathway related genes were determined. The results showed that fluoride reduced sperm quality, damaged testicular morphology, affected spermatogenesis, elevated IL-17A levels, and induced testicular pyroptosis. Bifidobacterium intervention alleviated adverse reproductive outcomes. Fluoride-activated testicular pyroptosis through both typical and atypical pathways, with IL-17A involvement. Bifidobacterium supplementation attenuated pyroptosis by downregulating IL-17A, inhibiting NLRP3 and PYRIN-mediated caspase-1 and caspase-11 dependent pathways in testis, thereby alleviating fluoride-induced male reproductive damage. In summary, this study uncovers the mechanism underlying fluorine-induced testicular pyroptosis and illustrates the novel protecting feature of Bifidobacterium against fluoride-induced harm to male reproduction, along with its potential regulatory mechanism. These results provide fresh perspectives on treating male reproductive dysfunction resulting from fluoride or other environmental toxins.

Bifidobacterium Relieved Fluoride-Induced Hepatic and Ileal Toxicity via Inflammatory Response and Bile Acid Transporters in Mice

Fluoride is a pervasive environmental contaminant. Prolonged excessive fluoride intake can inflict severe damage on the liver and intestines. Previous 16S rDNA sequencing revealed a decrease in ileal Bifidobacterium abundance during fluoride-induced hepatointestinal injury. Hence, this work aimed to investigate the possible mitigating function of Bifidobacterium on hepatointestinal injury caused by fluoride. Thirty-six 6-week-old C57BL/6J mice (equally divided between males and females) were allotted randomly to three groups: Ctrl group (distilled water), NaF group, and NaF + Ba group (100 mg/L NaF distilled water). After 10 weeks, the mice were given 1 × 109 CFU/mL Bifidobacterium solution (0.2 mL/day) intragastrically in the NaF + Ba group for 8 weeks, and the mice in other groups were given the same amount of distilled water. Dental damage, bone fluoride content, blood routine, liver and intestinal microstructure and function, inflammatory factors, and regulatory cholic acid transporters were examined. Our results showed that fluoride increased glutamic-oxalacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) activities, and the levels of lipopolysaccharide (LPS), IL-1β, IL-6, TNF-α, and IL-10 levels in serum, liver, and ileum. However, Bifidobacterium intervention alleviated fluoride-induced changes in the above indicators. In addition, Bifidobacterium reduced the mRNA expression levels of bile acid transporters ASBT, IBABP, OST-α, and OST-β in the ileum. In summary, Bifidobacterium supplementation relieved fluoride-induced hepatic and ileal toxicity via an inflammatory response and bile acid transporters in the liver and ileum of mice.

Molecular-level transformations of biomass burning-derived water-soluble organic carbon during dark aqueous OH oxidation: Insights from absorption, fluorescence, high-performance size exclusion chromatography and high-resolution mass spectrometry analysis

Biomass burning (BB) releases large amounts of water-soluble organic carbon (WSOC), which would undergo heterogenous oxidation processes that induce transformations in both molecular structures and compositions within BB WSOC. This study designed an aqueous oxidation initiated by OH radicals in the absence of light for WSOC extracted from smoke particles generated by burning of corn straw and fir wood. The BB WSOC was comprehensively characterized using a combination of UV-visible spectra, excitation-emission matrix fluorescence in conjunction with parallel factor analysis (EEM-PARAFAC), high-performance size exclusion chromatography (HPSEC), and high-resolution mass spectrometry (HRMS) analyses. Over the course of oxidation, both chromophores and fluorophores exhibited gradual decreases. Moreover, EEM-PARAFAC revealed a preferential degradation of larger-sized protein-like/phenol-like organic matters, accompanied by the accumulation and/or formation of humic-like substances in aged BB WSOC. HPSEC analysis showed notable changes in molecular weight (MW) distributions for both types of BB WSOC during oxidation. Specifically, high MW species (>1 kDa) displayed a tendency to form along with oxidation, possibly attributed to the formation of assemblies via intermolecular weak forces. After oxidation, evidence of CHO compound degradation and enrichment/formation of CHON compounds was observed for both types of BB WSOC. Remarkably, the resistant, degraded and produced molecules for BB WSOC were dominated by CHO (38-73 %) and lignin-like molecules (41-47 %), suggesting diverse responses to oxidation within these two groups. Furthermore, polyphenols experienced selective degradation, while CHON, aliphatic and poly-aromatic molecules tended to form during the oxidation process for both types of BB WSOC. In summary, this study provides a comprehensive understanding of the molecular-level transformations undergone by BB WSOC during dark aqueous OH oxidation. The findings significantly contribute to our insights into atmospheric evolution of BB WSOC, thereby playing a crucial role in accurately assessing their effects within climate models and informing policy decisions.

Investigating the molecular weight distribution of atmospheric water-soluble brown carbon using high-performance size exclusion chromatography coupled with diode array and fluorescence detectors

Atmospheric brown carbon (BrC) contain amounts of organic species, but their molecular weight (MW) distributions is still poorly understood. This study applied high-performance size exclusion chromatography (HPSEC) coupled with a diode array detector (DAD) and fluorescence detector (FLD) to characterize the MW distributions of typical chromophores and fluorophores within water-soluble BrC. The investigation focused on the spring season, encompassing both typical urban and rural aerosols. Our results showed that chromophores (at 254 and 365 nm), and humic-like and protein-like fluorophores identified by excitation-emission matrix parallel factor analysis (EEM-PARAFAC) within BrC were broadly distributed along the MW continuum (∼50-20,000 Da). This suggests that BrC mainly comprises complex chromophores and fluorophores with heterogeneous molecular sizes. High-MW (HMW, >1 kDa) species (66%-74%) dominated the chromophores at 254 and 365 nm. However, the latter chromophores were enriched with more HMW species. This result suggested that the HMW chromophores might contribute more to BrC absorption at longer wavelengths. The PARAFAC-derived fluorescent components also exhibited different MW distributions. Three humic-like substances (HULIS) were all dominated by HMW fractions (51%-74%), but protein-like fluorescent component (PLOM) enriched low-MW (LMW, <1 kDa) species (60%-66%). Furthermore, the molecular size (i.e., weight-averaged and number-averaged MW) and the ratios between HMW and LMW species decreased in the order highly-oxygenated HULIS > less-oxygenated HULIS > PLOM, indicating that the fluorophores with longer Em were generally related to larger MW. To our knowledge, this is the first report on the molecular size of individual fluorescent components within aerosol BrC. The results obtained here enhanced our knowledge of heterogeneous composition, complex physicochemical properties, and potential atmospheric fates of aerosol BrC.

Learning the heterogeneous representation of brain's structure from serial SEM images using a masked autoencoder

Introduction

The exorbitant cost of accurately annotating the large-scale serial scanning electron microscope (SEM) images as the ground truth for training has always been a great challenge for brain map reconstruction by deep learning methods in neural connectome studies. The representation ability of the model is strongly correlated with the number of such high-quality labels. Recently, the masked autoencoder (MAE) has been shown to effectively pre-train Vision Transformers (ViT) to improve their representational capabilities.

Methods

In this paper, we investigated a self-pre-training paradigm for serial SEM images with MAE to implement downstream segmentation tasks. We randomly masked voxels in three-dimensional brain image patches and trained an autoencoder to reconstruct the neuronal structures.

Results and discussion

We tested different pre-training and fine-tuning configurations on three different serial SEM datasets of mouse brains, including two public ones, SNEMI3D and MitoEM-R, and one acquired in our lab. A series of masking ratios were examined and the optimal ratio for pre-training efficiency was spotted for 3D segmentation. The MAE pre-training strategy significantly outperformed the supervised learning from scratch. Our work shows that the general framework of can be a unified approach for effective learning of the representation of heterogeneous neural structural features in serial SEM images to greatly facilitate brain connectome reconstruction.

Trends and characteristics of COVID-19 and cardiovascular disease related studies

Introduction: The new coronavirus has caused a pandemic that has infected hundreds of millions of people around the world since its outbreak. But the cardiovascular damage caused by the new coronavirus is unknown. We have analyzed the current global scenario and the general pattern of growth. After summarizing the known relationship between cardiovascular diseases and new coronary pneumonia, relevant articles are analyzed through bibliometrics and visualization. Methods: Following our pre-designed search strategy, we selected publications on COVID-19 and cardiovascular disease in the Web of Science database. In our relevant bibliometric visualization analysis, a total of 7,028 related articles in the WOS core database up to 20th October 2022 were summarized, and the most prolific authors, the most prolific countries, and the journals and institutions that published the most articles were summarized and quantitatively analyzed. Results: SARS-CoV-2 is more infectious than SARS-CoV-1 and has significant involvement in the cardiovascular system in addition to pulmonary manifestations, with a difference of 10.16% (20.26%/10.10%) in the incidence of cardiovascular diseases. The number of cases increases in winter and decreases slightly in summer with temperature changes, but the increase in cases tends to break out of seasonality across the region as mutant strains emerge. The co-occurrence analysis found that with the progress of the epidemic, the research keywords gradually shifted from ACE2 and inflammation to the treatment of myocarditis and complications, indicating that the research on the new crown epidemic has entered the stage of prevention and treatment of complications. Conclusion: When combined with the current global pandemic trend, how to improve prognosis and reduce human body damage could become a research focus. At the same time, timely detection, prevention, and discovery of new mutant strains have also become key tasks in the fight against the epidemic, and full preparations have been made to prevent the spread of the next wave of mutant strains, and still need to continue to pay attention to the differential performance of the variant "omicron."

Pembrolizumab monotherapy versus chemotherapy in platinum-pretreated, recurrent or metastatic nasopharyngeal cancer (KEYNOTE-122): an open-label, randomized, phase III trial

BACKGROUND

Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented.

PATIENTS AND METHODS

KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population.

RESULTS

Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage).

CONCLUSION

Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.

Insight into the evolution characteristics on molecular weight of compost dissolved organic matters using high-performance size exclusion chromatography combined with a two-dimensional correlation analysis

The information on molecular weight (MW) characteristics of DOM and relevant evolution behaviors during composting are limited. In this study, DOM extracted from co-composting of chicken manure and rice husks were comprehensively analyzed by using high-performance size exclusion chromatography (HPSEC) combined with a two-dimensional correlation spectroscopy (2D COS) to explore the evolution characteristics of MW of compost DOM. The HPSEC detected at UV of 254 nm and at fluorescence (FL) Ex/Em wavelengths (315/410, 270/455 nm) all showed a gradual increase in both weight-average and number-average MW for DOM, suggesting that the large MW fractions were continuously generated and polymerized during composting. The 2D COS applied on HPSEC-UV and -FL further identified the key active MW chromophoric (i.e., 0.5, 7.2. 9.5, 26.3, 30.7, and 83.9 kDa) and fluorophoric (i.e., 0.55 and 3.5 kDa) molecules that mainly participated in the transformation processes of compost DOM. Moreover, these active MW species were preferentially formed by the order of small to large molecules. A hetero-2D COS analysis disclosed the change sequence in the order of 0.5 and 7.2 kDa chromophores → 3.5 kDa fluorophores, and the 0.55 and 3.5 kDa fluorophores → 26.3 and 83.9 kDa chromophores.

Smart data collection for CryoEM

This report provides an overview of the discussions, presentations, and consensus thinking from the Workshop on Smart Data Collection for CryoEM held at the New York Structural Biology Center on April 6-7, 2022. The goal of the workshop was to address next generation data collection strategies that integrate machine learning and real-time processing into the workflow to reduce or eliminate the need for operator intervention.

Modulation of autophagy as a therapeutic strategy for Toxoplasma gondii infection

Toxoplasma gondii infection is a severe health threat that endangers billions of people worldwide. T. gondii utilizes the host cell membrane to form a parasitophorous vacuole (PV), thereby fully isolating itself from the host cell cytoplasm and making intracellular clearance difficult. PV can be targeted and destroyed by autophagy. Autophagic targeting results in T. gondii killing via the fusion of autophagosomes and lysosomes. However, T. gondii has developed many strategies to suppress autophagic targeting. Accordingly, the interplay between host cell autophagy and T. gondii is an emerging area with important practical implications. By promoting the canonical autophagy pathway or attenuating the suppression of autophagic targeting, autophagy can be effectively utilized in the development of novel therapeutic strategies against T gondii. Here, we have illustrated the complex interplay between host cell mediated autophagy and T. gondii. Different strategies to promote autophagy in order to target the parasite have been elucidated. Besides, we have analyzed some potential new drug molecules from the DrugBank database using bioinformatics tools, which can modulate autophagy. Various challenges and opportunities focusing autophagy mediated T. gondii clearance have been discussed, which will provide new insights for the development of novel drugs against the parasite.

Self-Assembly Vertical Graphene-Based MoO3 Nanosheets for High Performance Supercapacitors

Supercapacitors have been extensively studied due to their advantages of fast-charging and discharging, high-power density, long-cycling life, low cost, etc. Exploring novel nanomaterial schemes for high-performance electrode materials is of great significance. Herein, a strategy to combine vertical graphene (VG) with MoO₃ nanosheets to form a composite VG/MoO₃ nanostructure is proposed. VGs as transition layers supply rich active sites for the growth of MoO₃ nanosheets with increasing specific surface areas. The VG transition layer further improves the electric contact and adhesion of the MoO₃ electrode, simultaneously stabilizing its volume and crystal structure during repeated redox reactions. Thus, the prepared VG/MoO₃ nanosheets have been demonstrated to exhibit excellent electrochemical properties, such as high reversible capacitance, better cycling performance, and high-rate capability.

Antiviral Properties of Baicalin: a Concise Review

Baicalin is one of the bioactive flavonoid glycosides isolated from the dried root of Scutellaria baicalensis Georgi, Lamiaceae, with antiviral properties. In recent years, the antiviral activity of baicalin has been widely investigated to explore its molecular mechanism of action. In this mini-review, the molecular mechanisms of action of baicalin as an antiviral agent are evaluated, which included three categories: the inhibition or stimulation of JAK/STAT, TLRs, and NF-κB pathways; up or down modulation of the expression levels of IFN, IL, SOCS1/3, PKR protein, Mx1 protein, and AP-1 protein; and inhibition of cell apoptosis caused by virus infection. In addition, clinical studies of baicalin are also discussed. This literature search suggested that baicalin can serve as a potential candidate for the development of a novel broad-spectrum antiviral drug.

Neutrophil-Lymphocyte Ratio and Absolute Lymphocyte Count as Prognostic Markers in Patients Treated with Curative-intent Radiotherapy for Non-small Cell Lung Cancer

AIMS

The neutrophil-lymphocyte ratio (NLR) and the absolute lymphocyte count (ALC) have been proposed as prognostic markers in non-small cell lung cancer (NSCLC). The objective of this study was to examine the association of NLR/ALC before and after curative-intent radiotherapy for NSCLC on disease recurrence and overall survival.

MATERIALS AND METHODS

A retrospective study of consecutive patients who underwent curative-intent radiotherapy for NSCLC across nine sites in the UK from 1 October 2014 to 1 October 2016. A multivariate analysis was carried out to assess the ability of pre-treatment NLR/ALC, post-treatment NLR/ALC and change in NLR/ALC, adjusted for confounding factors using the Cox proportional hazards model, to predict disease recurrence and overall survival within 2 years of treatment.

RESULTS

In total, 425 patients were identified with complete blood parameter values. None of the NLR/ALC parameters were independent predictors of disease recurrence. Higher pre-NLR, post-NLR and change in NLR plus lower post-ALC were all independent predictors of worse survival. Receiver operator curve analysis found a pre-NLR > 2.5 (odds ratio 1.71, 95% confidence interval 1.06-2.79, P < 0.05), a post-NLR > 5.5 (odds ratio 2.36, 95% confidence interval 1.49-3.76, P < 0.001), a change in NLR >3.6 (odds ratio 2.41, 95% confidence interval 1.5-3.91, P < 0.001) and a post-ALC < 0.8 (odds ratio 2.86, 95% confidence interval 1.76-4.69, P < 0.001) optimally predicted poor overall survival on both univariate and multivariate analysis when adjusted for confounding factors. Median overall survival for the high-versus low-risk groups were: pre-NLR 770 versus 1009 days (P = 0.34), post-NLR 596 versus 1287 days (P ≤ 0.001), change in NLR 553 versus 1214 days (P ≤ 0.001) and post-ALC 594 versus 1287 days (P ≤ 0.001).

CONCLUSION

NLR and ALC, surrogate markers for systemic inflammation, have prognostic value in NSCLC patients treated with curative-intent radiotherapy. These simple and readily available parameters may have a future role in risk stratification post-treatment to inform the intensity of surveillance protocols.

Embracing informed learner self-assessment during debriefing: the art of plus-delta

The healthcare simulation field has no shortage of debriefing options. Some demand considerable skill which serves as a barrier to more widespread implementation. The plus-delta approach to debriefing offers the advantages of conceptual simplicity and ease of implementation. Importantly, plus-delta promotes learners' capacity for a self-assessment, a skill vital for safe clinical practice and yet a notorious deficiency in professional practice. The plus-delta approach confers the benefits of promoting uptake of debriefing in time-limited settings by educators with both fundamental but also advanced skills, and enhancing essential capacity for critical self-assessment informed by objective performance feedback. In this paper, we describe the role of plus-delta in debriefing, provide guidance for incorporating informed learner self-assessment into debriefings, and highlight four opportunities for improving the art of the plus delta: (a) exploring the big picture vs. specific performance issues, (b) choosing between single vs. double-barreled questions, (c) unpacking positive performance, and (d) managing perception mismatches.

Dendritic Cells: Versatile Players in Renal Transplantation

Dendritic cells (DCs) induce and regulate adaptive immunity through migrating and maturing in the kidney. In this procedure, they can adopt different phenotypes—rejection-associated DCs promote acute or chronic injury renal grafts while tolerogenic DCs suppress the overwhelmed inflammation preventing damage to renal functionality. All the subsets interact with effector T cells and regulatory T cells (Tregs) stimulated by the ischemia–reperfusion procedure, although the classification corresponding to different effects remains controversial. Thus, in this review, we discuss the origin, maturation, and pathological effects of DCs in the kidney. Then we summarize the roles of divergent DCs in renal transplantation: taking both positive and negative stages in ischemia–reperfusion injury (IRI), switching phenotypes to induce acute or chronic rejection, and orchestrating surface markers for allograft tolerance via alterations in metabolism. In conclusion, we prospect that multidimensional transcriptomic analysis will revolute researches on renal transplantation by addressing the elusive mononuclear phagocyte classification and providing a holistic view of DC ontogeny and subpopulations.

Predicting the Risk of Disease Recurrence and Death Following Curative-intent Radiotherapy for Non-small Cell Lung Cancer: The Development and Validation of Two Scoring Systems From a Large Multicentre UK Cohort

AIMS

There is a paucity of evidence on which to produce recommendations on neither the clinical nor the imaging follow-up of lung cancer patients after curative-intent radiotherapy. In the 2019 National Institute for Health and Care Excellence lung cancer guidelines, further research into risk-stratification models to inform follow-up protocols was recommended.

MATERIALS AND METHODS

A retrospective study of consecutive patients undergoing curative-intent radiotherapy for non-small cell lung cancer from 1 October 2014 to 1 October 2016 across nine UK trusts was carried out. Twenty-two demographic, clinical and treatment-related variables were collected and multivariable logistic regression was used to develop and validate two risk-stratification models to determine the risk of disease recurrence and death.

RESULTS

In total, 898 patients were included in the study. The mean age was 72 years, 63% (562/898) had a good performance status (0-1) and 43% (388/898), 15% (134/898) and 42% (376/898) were clinical stage I, II and III, respectively. Thirty-six per cent (322/898) suffered disease recurrence and 41% (369/898) died in the first 2 years after radiotherapy. The ASSENT score (age, performance status, smoking status, staging endobronchial ultrasound, N-stage, T-stage) was developed, which stratifies the risk for disease recurrence within 2 years, with an area under the receiver operating characteristic curve (AUROC) for the total score of 0.712 (0.671-0.753) and 0.72 (0.65-0.789) in the derivation and validation sets, respectively. The STEPS score (sex, performance status, staging endobronchial ultrasound, T-stage, N-stage) was developed, which stratifies the risk of death within 2 years, with an AUROC for the total score of 0.625 (0.581-0.669) and 0.607 (0.53-0.684) in the derivation and validation sets, respectively.

CONCLUSIONS

These validated risk-stratification models could be used to inform follow-up protocols after curative-intent radiotherapy for lung cancer. The modest performance highlights the need for more advanced risk prediction tools.

RV Pacing Percentage

Introduction

Chronic right ventricular pacing (RVP) has been associated with dyssynchrony, leading to increased mortality. However, there have been discrepancies in previous reports in the effect of RVP levels.

Objective

To sub-stratify mortality risk by age for different RVP level groups within a large real-world ICD cohort.

Methods

Optum® de-identified electronic health records were linked to the Medtronic Carelink data to identify dual chamber ICD recipients (2007–2017). RVP level was based on median daily pacing during the first 90 days post-implant and categorized either into groups with a cutoff of 40%, or with groups of 0–9%, 10–19%, 20–29%, 30–39%, 40–49%, and 50–100%. The endpoint was death more than 90 days post-implant. Kaplan-Meier survival curves, log-rank tests, and Cox regression were used to analyze the relationship between RVP and risk of death.

Results

Among 14,832 ICD patients (median age 67; 74.0% male), there were 2,602 deaths within 10 years after implant. In unadjusted comparisons, high RVP (&gt;40%) increased the risk of death relative to low RVP (≤40%) (p&lt;0.001). This effect remained significant in older cohort (≥67 years old at implant) (p&lt;0.001), but not in younger cohort (&lt;67 years old) (p=0.955) (Figure). After controlling for age, gender, pacing mode, MI, SCA, HF hospitalization, diabetes, and renal dysfunction, similar or increased risk was associated with higher pacing groups relative to the 0–9% pacing group in the older cohort, but not in the younger cohort.

Conclusions

Our data from a large contemporaneous real-world source suggests that older age or characteristics associated with age make patients more sensitive to chronic RVP effects. These results help reconcile differences observed in prior studies.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic, Inc.

Clinical outcomes from out-of-hospital cardiac arrest in low-resource settings - A scoping review

AIM OF THE SCOPING REVIEW

Scientific recommendations on resuscitation are typically formulated from the perspective of an ideal resource environment, with little consideration of applicability in lower-income countries. We aimed to determine clinical outcomes from out-of-hospital cardiac arrest (OHCA) in low-resource countries, to identify shortcomings related to resuscitation in these areas and possible solutions, and to suggest future research priorities.

DATA SOURCES

This scoping review was part of the continuous evidence evaluation process of the International Liaison Committee on Resuscitation (ILCOR), and was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews. We identified low-resource countries as countries with a low- or middle gross national income per capita (World Bank data). We performed a literature search on outcomes after OHCA in these countries, and we extracted data on the outcome. We applied descriptive statistics and conducted a post-hoc correlation analysis of cohort size and ROSC rates.

RESULTS

We defined 24 eligible studies originating from middle-income countries, but none from low-income regions, suggesting a reporting bias. The number of reported patients in these studies ranged from 54 to 3214. Utstein-style reporting was rarely used. Return of spontaneous circulation varied from 0% to 62%. Fifteen studies reported on survival to hospital discharge (between 1.0 and 16.7%) or favourable neurological outcome (between 1.0 and 9.3%). An inverse correlation was found for study cohort size and the rate of return of spontaneous circulation (ρ = -0.48, p = 0.034).

CONCLUSION

Studies of OHCA outcomes in low-resource countries are heterogeneous and may be compromised by reporting bias. Minimum cardiopulmonary resuscitation standards for low-resource settings should be developed collaboratively involving local experts, respecting culture and context while balancing competing health priorities.

The prokaryotic expression, polyclonal antibody preparation, and subcellular localization of the transmembrane protein NS2A of the duck Tembusu virus

Duck Tembusu virus (DTMUV) is a single-stranded, positive-sense RNA arbovirus, belonging to the genus Flavivirus, the family Flaviviridae. As a transmembrane protein, non-structural protein 2A (NS2A) plays an important role in virion assembly, replication complex and antagonizing host immune response. Since NS2A protein contains many hydrophobic amino acids, it is hard to gain the full-length protein of NS2A for prokaryotic expression. Therefore, to make a deep study, prokaryotic expression and polyclonal antibody preparation of truncated DTMUV NS2A was performed. The truncated NS2A gene (178-450 bp) was obtained, and sub-cloned into the prokaryotic vector pGEX-4T-1 (pGEX-4T-1-NS2A178-450bp). Subsequently, the recombinant GST-NS2A60-150aa protein was successfully expressed in E. coli BL21 (DE3) with the induction by 0.3 mmol/l isopropyl β-D-thiogalactoside (IPTG) for 6 h at 37°C. The GST-NS2A60-150aa protein was extracted from the gel. The BALB/c mice were immunized with the purified recombinant NS2A protein to prepare polyclonal antibodies against the truncated NS2A protein. The titer of the polyclonal antibodies, determined by ELISA analysis, was 1:128,000. The specificity of the polyclonal antibodies (mPAb-DTMUV-NS2A60-150aa) were verified by Western blot analysis. Furthermore, the indirect immunofluorescence (IFA) was performed to explore the subcellular localization of NS2A. NS2A protein was, in the transfected cells, located mainly around nucleus in the endoplasmatic reticulum. Taken together, our study provided a useful tool for the further exploration of the biological functions and molecular mechanism of DTMUV NS2A. Keywords: duck Tembusu virus; non-structural protein 2A; prokaryotic expression; polyclonal antibodies; subcellular location.

[Expression and correlation analysis of hypoxia inducible factor 1α and autophagy related molecules in rat nucleus pulposus cells under hypoxia]

Objective

To investigate the expression and correlation of hypoxia inducible factor 1α (HIF-1α) and autophagy related molecules (Beclin1 and LC3B) in rat nucleus pulposus cells under hypoxia in vitro.

Methods

The nucleus pulposus cells were extracted from the nucleus pulposus of healthy adult Sprague Dawley rats and passaged. The 3rd generation cells were identified by HE staining and collagenase type Ⅱ immunofluorescence staining and randomly divided into 4 groups. The cells in group A were cultured for 8 hours under normal oxygen condition (37℃, 5%CO ₂, 20%O ₂); the cells in group B were cultured for 8 hours under hypoxia condition (37℃, 5%CO ₂, 1%O ₂); the cells in group C were transfected with HIF-1α-small interfering RNA and cultured for 8 hours under hypoxia condition; and the cells in group D were cultured with autophagy inhibitor 3-MA for 8 hours under hypoxia condition. Western blot and real-time fluorescence quantitative PCR (qRT-PCR) were used to detect the expressions of HIF-1α and autophagy related molecules (Beclin1 and LC3B) in all groups.

Results

HE staining of the 3rd generation nucleus pulposus cells showed that the cytoplasm was light pink and the nucleus was blue black, and the collagenase type Ⅱ immunofluorescence staining was positive. Western blot and qRT-PCR results showed that the relative expressions of HIF-1α, Beclin1, and LC3B proteins and genes in group B were significantly higher than those in group A ( P<0.05); the relative expressions of HIF-1α, Beclin1, and LC3B proteins and genes in group C were significantly lower than those in group B ( P<0.05). There was no significant difference in the relative expression of HIF-1α protein and gene between groups B and D ( P>0.05); while the relative expressions of Beclin1 and LC3B proteins and genes in group D were significant lower than those in group B ( P<0.05).

Conclusion

Hypoxia can induce the expressions of HIF-1α and autophagy related molecules (Beclin1 and LC3B) in rat nucleus pulposus cells, and HIF-1α in rat nucleus pulposus cells under hypoxia is related to the expression of autophagy related molecules, that is, down-regulation of HIF-1α can significantly reduce the expression of autophagy related molecules, while the down-regulation of autophagy levels under hypoxia has no or little effect on the expression of HIF-1α.

Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth

The outer Solar System object (486958) Arrokoth (provisional designation 2014 MU₆₉) has been largely undisturbed since its formation. We studied its surface composition using data collected by the New Horizons spacecraft. Methanol ice is present along with organic material, which may have formed through irradiation of simple molecules. Water ice was not detected. This composition indicates hydrogenation of carbon monoxide-rich ice and/or energetic processing of methane condensed on water ice grains in the cold, outer edge of the early Solar System. There are only small regional variations in color and spectra across the surface, which suggests that Arrokoth formed from a homogeneous or well-mixed reservoir of solids. Microwave thermal emission from the winter night side is consistent with a mean brightness temperature of 29 ± 5 kelvin.

P1445 DORv and window: a case of an uncorrected double outlet right ventricle with d-transposition of great arteries with concomitant aortopulmonary window in a 31-year-old female

Funding Acknowledgements

none

Double outlet right ventricle (DORV) is a rare type of ventriculo-arterial connection occurring in about 1-3% of congenital heart defects. Moreover, transposition of the great arteries, wherein the aorta is anterior and to the right of the pulmonary artery (D-TGA), accounts for only 26% of cases of DORV. An aortopulmonary window, on the other hand, represents approximately only 0.2% of all congenital cardiac lesions. A case of DORV with D-TGA and pulmonary stenosis with a concomitant aortopulmonary window has never been reported, particularly in an adult in the third decade of life and without any history of surgical repair.

We present the case of a 31-year-old female who had sought consult for left-sided weakness. On physical examination, a grade IV/VI systolic murmur was heard at the left anterior chest and cyanosis of the digits of the upper and lower extremities were noted. Transthoracic echocardiogram revealed a non-restrictive ventricular septal defect (VSD) and segmental approach showed atrial and visceral situs solitus, levocardia, and atrioventricular concordance. However, there was ventriculoarterial discordance with fusiform aneurysmal dilatation of the aorta, which was noted to be at the right of and anterior to the pulmonary artery. Both great vessels arose from the right ventricle. Other echocardiographic findings included dilated right atrium, dilated and hypertrophied right ventricle with volume and pressure overload, global left ventricular hypokinesia with mild systolic dysfunction, and moderate to severe aortic regurgitation. The above complex congenital anomalies were confirmed via transesophageal echocardiogram and cardiac magnetic resonance imaging (MRI). Furthermore, pulmonary valve stenosis and aortopulmonary window, that was 3.5 centimeters in length located at the level of the proximal ascending aorta and main pulmonary artery, were seen on the MRI.

Various cardiac imaging modalities aided in cinching the diagnosis for this very rare complex congenital case in an adult reaching the third decade of life. Palliative care was deemed best for this patient due to the severity of her cardiac condition.

Abstract P1445 Figure 1.

The financial burden of acute odontogenic infections: the South Australian experience

BACKGROUND

Acute odontogenic infections are a common surgical emergency managed by public hospitals in Australia which cause considerable patient morbidity and occasionally, mortality. Despite posing a significant public health burden, Australian data evaluating the cost of the management of these patients are lacking. This study assessed the patient and treatment variables associated with inpatient management of deep odontogenic infections, and their respective financial impact, at a statewide Oral & Maxillofacial service.

METHODS

A retrospective audit was carried out of patients with deep odontogenic infections at our institution, over a 7-year period. The primary outcome was the total cost of admission. Secondary outcomes included treatment received, operating room time, return-to-theatre, length of admission (LOS), and intensive care unit (ICU) use. Cost variables were assessed against the total LOS and ICU use to determine clinical predictors affecting outcome.

RESULTS

Four hundred and sixty two patients met the inclusion criteria. The average cost per patient was $12 228 Australian Dollars. After multivariate analysis, variables most significantly associated with increased cost of care and LOS were high-risk infections with airway compromise, high admission white cell count and age.

CONCLUSION

Hospital-based management of deep-space odontogenic infections engender significant costs compared to early primary care intervention such as a dental extraction ($181/extraction).

4113Glucose lowering drugs or strategies, major adverse cardiovascular events and heart failure outcomes, and association with weight loss - meta-analysis of large cardiovascular outcome trials

Background

Glucose lowering drugs or strategies (GLDS) have varied effects on major adverse cardiovascular events (MACE) and heart failure (HF) in cardiovascular outcomes trials. Mechanisms driving cardiovascular risk reduction remain elusive.

Methods

We searched MEDLINE, PubMed, and meeting abstracts up to 11/21/2018 for large GLDS cardiovascular outcome trials (CVOTs) in patients with or at risk for type 2 diabetes. Primary endpoints of MACE and HF were evaluated with random effects risk ratios (RR) and explored by baseline CVD subgroups and meta-regression by weight change across treatment arms.

Results

In 27 GLDS CVOTs, a total 207,820 patients, median age 63 years, 64% male, 64% CVD and 11% with prior HF were studied over a mean 3.8 years with 20,118 (10%) patients having MACE and 7,212 (4%) a HF event. Compared with standard care, GLDS overall lowered MACE (RR 0.92, P<0.ehz745.01171) but not HF (RR 1.01, P=0.91). Across GLDS, the magnitude and directionality varied modestly for MACE RR (P-int=0.07) but markedly for HF (P-int<0.ehz745.01171). Meta-regression showed a change in HF RR by 6% (95% CI 3%-9%) per 1 kg weight gain/loss between treatment arms (P=0.0006; Figure). In 9 trials of GLDS that achieved marked weight loss (lifestyle, GLP1 agonists, SGLT2 inhibitors), MACE benefit was confined to patients with baseline CVD (RR 0.89 [0.84–0.95] versus without (RR 1.02 [0.91–1.15]; P-int=0.01) with consistent HF effect (RR 0.80 [0.72–0.88] vs RR 0.76 [0.56–1.03]; P-int=0.74).

Heart Failure Risk and Changes in Weight

Conclusion

HF outcomes were improved with GLDS that lower weight. Among diabetes GLDS that lower weight, there was a robust risk reduction in atherothrombotic and heart failure events, with the MACE benefit confined to patients with established CVD.

Acknowledgement/Funding

Heart and Stroke Foundation

5970Morbidity and mortality in patients precluded for transvenous pacemaker implantation: experience with the Micra transcatheter pacemaker

Background

The Micra transcatheter pacemaker has proven to be a safe and effective alternative to transvenous pacemakers (TVPs). However, the safety profile after Micra implantation in patients deemed poor candidates for TVPs is poorly understood.

Purpose

To evaluate the safety and all-cause mortality outcomes in Micra recipients stratified by whether or not they were precluded for therapy with TVP.

Methods

Micra patients from the Micra Transcatheter Pacing (IDE) Study, Continued Access (CA) study, and Post-Approval Registry (PAR) were divided into groups based upon whether or not the implanting physician considered the patient to be precluded from receiving a transvenous pacing system. All-cause mortality was compared between the Micra patient groups and patients receiving a single-chamber transvenous pacing system (SC-TVP) since 2010 from the Medtronic product surveillance registry using univariate and multivariate Cox models.

Results

Among 2,819 patients who underwent a Micra implant attempt, the overall major complication rate through 24 months was 3.5%. In these patients, 548 were deemed precluded from TVP implantation. Prior device infection or bacteremia (38.9%), venous access issues (36.1%) and thrombosis (10.2%) were amongst the most common causes of preclusion for TVP implantation. These patients were younger (71.7 vs. 76.7 years), more frequently on hemodialysis (26.3% vs. 2.5%), and more often had a prior CIED implanted (38.4% vs. 4.4%) than non-precluded patients. Over an average follow-up of 13.5±11.1 months, all-cause mortality was significantly higher in precluded Micra patients compared with SC-TVP patients (HR: 2.16, 95% CI: 1.54–3.2, P<0.001) (Figure 1). However, there was no significant difference in all-cause mortality when comparing non-precluded Micra patients and SC-TVP patients (HR: 1.12, 95% CI: 0.86–1.44, P=0.401). Acute all-cause death (within 1 month) among Micra patients was 2.74% and 1.32% in the precluded and non-precluded TVP groups, respectively. The procedure-related death rate was 0.55% for the TVP precluded group and 0.13% for the not precluded group (P=0.092). The major complication rate through 24-months was similar between the two Micra groups (4.0% vs 3.4%, P=0.630).

All-cause mortality for Micra and SC-TVP

Conclusion

The overall safety profile of Micra remains is in line with previously reported data. All-cause mortality risk (both acute and long term) appears to be higher in patients who were precluded from receiving TVP.

Acknowledgement/Funding

Supported by Medtronic