A Giant Frontoethmoidal Ivory Osteoma Causing Cosmetic and Visual Problem: A Case Report.

Osteomas are slow growing fibro-osseous lesions. Very rare to occur in paranasal sinuses. Small osteomas don't require any intervention. Giant osteomas may require surgical intervention due to its cosmetic and functional compromises. A 28 year old male presented with swelling over forehead and left orbit for more than 4 years. The swelling is around 6 × 5 cm with gross lateral and inferior deviation of left eyeball. Extradural fronto-ethmoidectomy was done with combined external and endoscopic approach. There was pearly white bony hard, fixed tumor mass seen infiltrating anterior and posterior table of frontal bone. All the tumors removed in piecemeals. Wait and watch policy is the usual treatment policy for small and asymptomatic osteomas. Combine external and endoscopic approach is the treatment of choice for giant frontoethmoid osteoma.

Malignancy of Nose and Paranasal Sinuses: An Institutional Study in Central India.

INTRODUCTION: Malignancy of the nose and paranasal sinuses is a highly heterogeneous tumor group that arises from various cell types commonly seen in the fifth to sixth decades of life, with twice as much commonness in males. Patients present with varied clinical presentations like nasal obstruction, facial swelling, orbital complications, etc. Squamous cell carcinoma and adenocarcinoma are the most common variant. Surgery followed by adjuvant chemo or radiotherapy is the treatment of choice. METHODS: The study was undertaken in the Department of Otorhinolaryngology All India Institute of Medical Sciences, Bhopal, India, from 2021 to 2023. It was a retrospective study in which patients diagnosed and underwent treatment in the last 2 years were enrolled. Data were retrieved from the medical record department and surgical registry. Twenty-eight patients were recruited for the study. Detailed history, clinical examination, imaging findings, surgical plans, postoperative adjuvant therapy details, and histopathological findings were recorded. RESULTS: There were 18 (64.2%) males and 10 (35.8%) females, with a male-to-female ratio of 1.8: 1. The mean age of patients was 50.5 years. Facial swelling was the most frequent symptom (n=15, 54%). Twenty-one (75%) patients use chewable tobacco, while sixteen (57%) are smokers. All our patients belong to the lower socioeconomic group. Endoscopic resection was done in 15 (62.5%) patients, and combined open and endoscopic approaches were used in 9 (37.5%) patients. The most common histological variant was squamous cell carcinoma (n=8, 28%). CONCLUSION: Malignancy of the nose and paranasal sinus is very rare. They presented with varied masked clinical presentations of benign diseases. Early identification and high clinical suspicion, along with imaging studies, are pivotal in managing malignancy of the nose and paranasal sinuses.

A multi-cohort genome-wide association study in African ancestry individuals reveals risk loci for primary open-angle glaucoma.

Primary open-angle glaucoma (POAG), the leading cause of irreversible blindness worldwide, disproportionately affects individuals of African ancestry. We conducted a genome-wide association study (GWAS) for POAG in 11,275 individuals of African ancestry (6,003 cases; 5,272 controls). We detected 46 risk loci associated with POAG at genome-wide significance. Replication and post-GWAS analyses, including functionally informed fine-mapping, multiple trait co-localization, and in silico validation, implicated two previously undescribed variants (rs1666698 mapping to DBF4P2; rs34957764 mapping to ROCK1P1) and one previously associated variant (rs11824032 mapping to ARHGEF12) as likely causal. For individuals of African ancestry, a polygenic risk score (PRS) for POAG from our mega-analysis (African ancestry individuals) outperformed a PRS from summary statistics of a much larger GWAS derived from European ancestry individuals. This study quantifies the genetic architecture similarities and differences between African and non-African ancestry populations for this blinding disease.

Oxidative stress induces lysosomal membrane permeabilization and ceramide accumulation in retinal pigment epithelial cells.

Oxidative stress has been implicated in the pathogenesis of age-related macular degeneration, the leading cause of blindness in older adults, with retinal pigment epithelium (RPE) cells playing a key role. To better understand the cytotoxic mechanisms underlying oxidative stress, we used cell culture and mouse models of iron overload, as iron can catalyze reactive oxygen species formation in the RPE. Iron-loading of cultured induced pluripotent stem cell-derived RPE cells increased lysosomal abundance, impaired proteolysis and reduced the activity of a subset of lysosomal enzymes, including lysosomal acid lipase (LIPA) and acid sphingomyelinase (SMPD1). In a liver-specific Hepc (Hamp) knockout murine model of systemic iron overload, RPE cells accumulated lipid peroxidation adducts and lysosomes, developed progressive hypertrophy and underwent cell death. Proteomic and lipidomic analyses revealed accumulation of lysosomal proteins, ceramide biosynthetic enzymes and ceramides. The proteolytic enzyme cathepsin D (CTSD) had impaired maturation. A large proportion of lysosomes were galectin-3 (Lgals3) positive, suggesting cytotoxic lysosomal membrane permeabilization. Collectively, these results demonstrate that iron overload induces lysosomal accumulation and impairs lysosomal function, likely due to iron-induced lipid peroxides that can inhibit lysosomal enzymes.

N-acetylcysteine and cysteamine bitartrate prevent azide-induced neuromuscular decompensation by restoring glutathione balance in two novel surf1-/- zebrafish deletion models of Leigh syndrome.

SURF1 deficiency (OMIM # 220110) causes Leigh syndrome (LS, OMIM # 256000), a mitochondrial disorder typified by stress-induced metabolic strokes, neurodevelopmental regression and progressive multisystem dysfunction. Here, we describe two novel surf1-/- zebrafish knockout models generated by CRISPR/Cas9 technology. While gross larval morphology, fertility, and survival into adulthood appeared unaffected, surf1-/- mutants manifested adult-onset ocular anomalies and decreased swimming activity, as well as classical biochemical hallmarks of human SURF1 disease, including reduced complex IV expression and enzymatic activity and increased tissue lactate. surf1-/- larvae also demonstrated oxidative stress and stressor hypersensitivity to the complex IV inhibitor, azide, which exacerbated their complex IV deficiency, reduced supercomplex formation, and induced acute neurodegeneration typical of LS including brain death, impaired neuromuscular responses, reduced swimming activity, and absent heartrate. Remarkably, prophylactic treatment of surf1-/- larvae with either cysteamine bitartrate or N-acetylcysteine, but not other antioxidants, significantly improved animal resiliency to stressor-induced brain death, swimming and neuromuscular dysfunction, and loss of heartbeat. Mechanistic analyses demonstrated cysteamine bitartrate pretreatment did not improve complex IV deficiency, ATP deficiency, or increased tissue lactate but did reduce oxidative stress and restore glutathione balance in surf1-/- animals. Overall, two novel surf1-/- zebrafish models recapitulate the gross neurodegenerative and biochemical hallmarks of LS, including azide stressor hypersensitivity that was associated with glutathione deficiency and ameliorated by cysteamine bitartrate or N-acetylcysteine therapy.

Using the Chick Embryo Model to Examine the Effects of Hypoxia Pre-conditioning of Uveal Melanoma Cells on Tumor Growth and Metastasis.

PURPOSE: Highly dynamic oxygen gradients occur within tumors that can result in a hypoxic response, contributing to tumor progression and metastasis. Evidence in uveal melanoma (UM) suggests an upregulated hypoxia response in some poor prognosis UM characterized by HIF1α signaling. We aimed to investigate the effects of exposure to hypoxia on tumor growth and dissemination in the chick embryo chorioallantoic membrane (CAM) model. METHODS: UM cell lines (MP41, 92.1, MP46, and OMM1) were grown in two-dimensional culture and pre-exposed to hypoxic (1% O2) conditions for 72 h. The effects of this hypoxia pre-conditioning on cell number and clonogenicity as compared with 21% O2 ("normoxia") were investigated prior to transplantation of the cells onto the CAM. Nodule-forming efficiency (NFE), nodule size, and the presence/absence of tumor cell dissemination were determined macroscopically and histologically. RESULTS: Exposure of UM cell lines to hypoxia upregulated HIF1α expression compared to cells cultured in normoxia. A 72-h pre-exposure to hypoxia significantly reduced cell number and clonogenicity in the MP41 and OMM1 cell lines while it had little effect in 92.1 and MP46 cells. When 72-h hypoxia pre-conditioned cells were grown in three-dimensions on the CAM, a reduction in NFE and nodule size was observed when compared with normoxic UM cells. All nodules were composed of proliferating (Ki-67+) Melan-A + cells and displayed chick blood vessel recruitment. Spread of UM cells into the adjacent CAM was observed; however, dissemination to the chick liver was only seen with 92.1 cells grown under normoxia. CONCLUSIONS: Hypoxia pre-conditioning does not appear to drive a metastatic phenotype in UM; however, further understanding of how oxygen dynamics within the tumor microenvironment regulates HIF1 signaling is needed to determine whether inhibitors of HIF signaling represent a therapeutic option in metastatic UM.

Transperons: RNA operons as effectors of coordinated gene expression in eukaryotes.

Coordinated gene expression allows spatiotemporal control of cellular processes and is achieved by the cotranscription/translation of functionally related genes/proteins. Prokaryotes evolved polycistronic messages (operons) to confer expression from a single promoter to efficiently cotranslate proteins functioning on the same pathway. Yet, despite having far greater diversity (e.g., gene number, distribution, modes of expression), eukaryotic cells employ individual promoters and monocistronic messages. Although gene expression is modular, it does not account for how eukaryotes achieve coordinated localized translation. The RNA operon theory states that mRNAs derived from different chromosomes assemble into ribonucleoprotein particles (RNPs) that act as functional operons to generate protein cohorts upon cotranslation. Work in yeast has now validated this theory and shown that intergenic associations and noncanonical histone functions create pathway-specific RNA operons (transperons) that regulate cell physiology. Herein the involvement of chromatin organization in transperon formation and programmed gene coexpression is discussed.

Communication with Patients on Mechanical Ventilation: A Review of Existing Technologies.

How to cite this article: Anand A, Nair RR, Kodamanchili S, Panda R, Bhardwaj KK, Gowthaman TB. Communication with Patients on Mechanical Ventilation: A Review of Existing Technologies. Indian J Crit Care Med 2022;26(6):756-757.

A short-term chick embryo in vivo xenograft model to study retinoblastoma cancer stem cells.

Purpose: Cancer stem cells (CSCs) reported in various tumors play a crucial role in tumorigenesis and metastasis of retinoblastoma (Rb). Following the efforts to reduce, replace, and refine the use of mammalian models, we aimed to establish a short-term xenograft for Rb to evaluate the CSC properties of CD133- Rb Y79 cells, using the well-established chick embryo chorioallantoic membrane (CE-CAM) assay. Methods: Y79 cells were cultured, labeled with two different dyes (CM-Dil Y79 and enhanced green fluorescent protein (eGFP)) and sorted for CD133- and CD133 + subsets. Two million cells from each of the labeled groups were transplanted onto the abraded CAM on embryonic day 7 (E7). On E14, the tumor nodule formation on CAM and spontaneous metastasis to the embryos were evaluated by confocal microscopy, in vivo imaging, and histology. Results: Y79 cells formed pink-white raised perivascular nodules with feeder vessels on the CAM with both the types of labeled CD133- cells. CD133- cells, when compared to CD133 + cells, demonstrated significantly larger tumor volume (40.45 ± 7.744 mm3 vs 3.478 ± 0.69 mm3, P = 0.0014) and higher fluorescence intensity (CM-Dil: AUF = 6.37 × 107 ± 7.7 × 106 vs 1.08 × 107 ± 1.6 × 106; P < 0.0001; eGFP: AUF = 13.94 × 104 ± 2.54 × 104 vs AUF = 1.39 × 104 ± 0.4 × 104; P = 0.0003). The metastatic potential of CD133- cells was also observed to be higher as noted by in vivo imaging and histopathology. Conclusion: This study highlights that CE-CAM is a feasible alternative nonmammalian model for evaluating tumorigenicity and metastatic potential of Y79 CSCs. Increased tumorigenicity and metastatic potential of CD133- subset of tumor cells substantiate their CSC properties.

An Aptamer-based mRNA Affinity Purification Procedure (RaPID) for the Identification of Associated RNAs (RaPID-seq) and Proteins (RaPID-MS) in Yeast.

RNA-RNA and RNA-protein interactions are involved in the regulation of gene expression. Here, we describe an updated and extended version of our RNA purification and protein identification (RaPID) protocol for the pulldown of aptamer-tagged mRNAs by affinity purification. The method takes advantage of the high affinity interaction between the MS2 RNA aptamer and the MS2 coat protein (MCP), as well as that between streptavidin-binding peptide (SBP) and streptavidin. Thus, it employs MCP-SBP fusions to affinity purify MS2-tagged target RNAs of interest over immobilized streptavidin. Purified aptamer-tagged mRNAs, along with any associated RNAs and proteins, are then sent for RNA sequencing (RaPID-seq) or mass spectrometry (RaPID-MS), which allows for the identification of bound cohort RNAs and proteins, respectively.

Evolving Trends of Button Battery Ingestion in Indian Children at a Tertiary Care Hospital.

INTRODUCTION: Foreign body ingestion is a common problem encountered in the pediatric age group. Impaction of lithium batteries of greater than 20-mm diameter in the esophagus is associated with severe complications. This study aimed at analyzing the evolving trends of button battery ingestion in pediatric age groups at our tertiary care center in terms of clinical presentation, intraoperative findings, and the correlation of various clinical variables. METHODS: A retrospective observational study was done. All children younger than 18 years with impaction of a button battery of size greater than 20 mm in the esophagus between January 2015 and December 2018 were included in the study. All children underwent removal of the battery using direct laryngoscopy/rigid esophagoscopy under general anesthesia. RESULTS: There were 100 children included in the study with a mean age of 29.92 months having 93 children (93%) younger than 6 years. The mean duration of impaction was 34.7 hours. Increased duration of impaction was associated with an increased risk of complications and an increased difficulty in removal. There was a significant correlation between the site of impaction and the age of the patient. Complications were seen in 10% of cases with severe complications in 6 cases. No fatalities were reported in this study. CONCLUSIONS: Button batteries impacted in the esophagus can lead to severe complications including death. There has been an increasing trend in the ingestion of button batteries over the last 4 years. A prompt diagnosis and emergent removal of the battery are crucial to minimize the rate of complications. Symptoms of stridor and dysphagia must be given more attention, and these children are prioritized because they are more prone to have complications. Furthermore, primary prevention and caregiver education should be emphasized, and the need for a legislation to change the policies for securing the batteries in their products must be endorsed.

Carboplatin- and Etoposide-Loaded Lactoferrin Protein Nanoparticles for Targeting Cancer Stem Cells in Retinoblastoma In Vitro.

Purpose: Cancer stem cells (CSCs) are known to contribute to tumor relapses by virtue of their chemoresistance. With the knowledge that nanoformulations can overcome drug resistance, we evaluated the efficacy and cytotoxicity of clinical-grade carboplatin (CPT)- and etoposide (ETP)-loaded lactoferrin nanoparticles (Lf-Nps) on total, CD133-enriched (non-CSC), and CD133-depleted (CSC) populations of retinoblastoma (Rb) Y79 cells. Methods: Physicochemical properties of drug-loaded Lf-Nps were measured with transmission electron microscopy and attenuated total reflectance-Fourier transform infrared. The encapsulation efficiency, uptake, and release of drug-loaded Lf-Nps were measured using high-performance liquid chromatography and a UV-visible spectrophotometer. Cytotoxicity of the standard and drug-loaded Lf-Nps was evaluated by the MTT assay. Results: The mean (SD) size and encapsulation efficiency of Lf-CPT and Lf-ETP were 61.2 (3.94) nm, 60% and 45.15 (5.85) nm, 38%, respectively, and the drug release efficiency was highest at pH 6. The increased drug uptake and lower release of drug-loaded Lf-Nps were observed in CSC and non-CSC populations compared to their standard forms. The relative increase of drug uptake and sustained intracellular retention of the drug-loaded Lf-Nps compared to standard drugs showed an enhanced cytotoxicity up to 50%, especially in Rb Y79 CSCs (IC50: CPT, 230.3; Lf-CPT, 118.2; ETP, 198.1; and Lf-ETP, 129) compared to non-CSCs. Conclusions: Our study documents an increase in drug uptake, retention, and cytotoxicity of Lf-CPT and Lf-ETP on Y79 CSCs and non-CSCs as compared to their standard drugs in vitro. The reversal of chemoresistance in the CSC population by nanoformulation appears promising with the potential to pave the way for improved targeted therapy and better clinical outcomes.

Multiplexed mRNA assembly into ribonucleoprotein particles plays an operon-like role in the control of yeast cell physiology.

Prokaryotes utilize polycistronic messages (operons) to co-translate proteins involved in the same biological processes. Whether eukaryotes achieve similar regulation by selectively assembling and translating monocistronic messages derived from different chromosomes is unknown. We employed transcript-specific RNA pulldowns and RNA-seq/RT-PCR to identify yeast mRNAs that co-precipitate as ribonucleoprotein (RNP) complexes. Consistent with the hypothesis of eukaryotic RNA operons, mRNAs encoding components of the mating pathway, heat shock proteins, and mitochondrial outer membrane proteins multiplex in trans, forming discrete messenger ribonucleoprotein (mRNP) complexes (called transperons). Chromatin capture and allele tagging experiments reveal that genes encoding multiplexed mRNAs physically interact; thus, RNA assembly may result from co-regulated gene expression. Transperon assembly and function depends upon histone H4, and its depletion leads to defects in RNA multiplexing, decreased pheromone responsiveness and mating, and increased heat shock sensitivity. We propose that intergenic associations and non-canonical histone H4 functions contribute to transperon formation in eukaryotic cells and regulate cell physiology.

RPGR isoform imbalance causes ciliary defects due to exon ORF15 mutations in X-linked retinitis pigmentosa (XLRP).

Mutations in retinitis pigmentosa GTPase regulator (RPGR) cause severe retinal ciliopathy, X-linked retinitis pigmentosa. Although two major alternatively spliced isoforms, RPGRex1-19 and RPGRORF15, are expressed, the relative importance of these isoforms in disease pathogenesis is unclear. Here, we analyzed fibroblast samples from eight patients and found that all of them form longer cilia than normal controls, albeit to different degrees. Although all mutant RPGRORF15 messenger RNAs (mRNAs) are unstable, their steady-state levels were similar or higher than those in the control cells, suggesting there may be increased transcription. Three of the fibroblasts that had higher levels of mutant RPGRORF15 mRNA also exhibited significantly higher levels of RPGRex1-19 mRNA. Four samples with unaltered RPGRex1-19 levels carried mutations in RPGRORF15 that resulted in this isoform being relatively less stable. Thus, in all cases, the RPGRex1-19/RPGRORF15 isoform ratio was increased, and this was highly correlative to the cilia extension defect. Moreover, overexpression of RPGRex1-19 (mimicking the increase in RPGRex1-19 to RPGRORF15 isoform ratio) or RPGRORF15 (mimicking reduction of the ratio) resulted in significantly longer or shorter cilia, respectively. Notably, the cilia length defect appears to be attributable to both the loss of the wild-type RPGRORF15 protein and to the higher levels of the RPGRex1-19 isoform, indicating that the observed defect is due to the altered isoform ratios. These results suggest that maintaining the optimal RPGRex1-9 to RPGRORF15 ratio is critical for cilia growth and that designing strategies that focus on the best ways to restore the RPGRex1-19/RPGRORF15 ratio may lead to better therapeutic outcomes.

Overexpression of metastasis-associated in colon cancer 1 in retinoblastoma.

INTRODUCTION: Metastasis-associated in colon cancer 1 (MACC1), one of the prognostic markers for colonic and other tumours was noted to be overexpressed in retinoblastoma (Rb) Y79 cancer stem cells. This prompted us to evaluate its expression in primary Rb tumour and serum samples with clinicopathologic correlation. The interacting partner, c-MET was also evaluated in primary tumour tissues to explore the activation of MACC1 signaling. METHODOLOGY: This study was done following institutional review board approval from participating institutes. Semiquantitative gene expression for MACC1 was evaluated using formalin-fixed paraffin-embedded sections and unfixed tumour samples from primary Rb cases (n = 44). Immunolocalization for MACC1 was assessed in primary Rb tumours (n = 22), bone marrow aspirates with metastasis (n = 3), and c-MET expression was also assessed in Rb tumours (n = 17). Serum MACC1 levels were analysed using enzyme-linked immunosorbent assay in samples collected from Rb patients undergoing enucleation (n = 31), Rb patients with proven clinical metastasis (n = 3), and compared to appropriate controls. Clinicopathologic correlation of MACC1 expression was analysed using the medical records with specific reference to histologic risk factors (HRF) for metastasis and differentiation. RESULTS: High expression of MACC1 gene was noted in all the tumour samples (n = 44), more so in cases with versus without HRF (p < 0.0001). In cases with HRF, MACC1 and c-MET showed diffuse nuclear and cytoplasmic staining whereas it was predominantly cytoplasmic in cases without HRF. Mean immunoreactivity score of MACC1 and c-MET tissue immunolocalization revealed that cases with HRF showed significantly higher expression compared to cases without HRF (p < 0.05). Unlike the findings in colonic tumours, serum levels of MACC1 were lower in patients compared to normal controls. CONCLUSION: Overexpression of MACC1 and c-MET in retinoblastoma tissues, specifically those with risk factors for metastasis, suggests its role in proliferation and possibly in invasion. However, the current data do not support it to be a clinical prognostic marker in retinoblastoma tumours. The inverse serum expression is an intriguing finding, which warrants further studies especially in retinoblastoma.

High Level of APOA1 in Blood and Maternal Fetal Interface Is Associated With Early Miscarriage.

Early miscarriage (EM) is one of the most devastating obstetrical complications globally affecting the quality of women's life. In the present study, we aimed to identify proteins that correlate with and could act as biomarkers for EM. We performed 2-dimensional gel electrophoresis in chorionic villi samples followed by mass spectrometry for identification of differential protein expression with EM. Proteomic studies detected a total 124 protein spots, out of which 83 spots were differentially expressed between EM and controls in chorionic villi samples. Matrix assisted laser desorbtion/ionization-time of flight (MALDI-TOF) mass spectrometry analysis revealed Apolipoprotein A1 (APOA1) to be the most upregulated protein in the EM group that was validated by Western blotting and Enzyme-linked immunosorbent assay (ELISA) . We found low but not statistically significant level of APOA1 on 21st day of menstruation in comparison to the 7th day. APOA1 level was observed to be the lowest in the first trimester. Hence, this study suggests that low APOA1 expression is critical in establishing pregnancy and elevated APOA1 expression in chorionic villi correlates with EM. Similar observation in serum samples suggests its potential as a marker for the risk of EM.

Altered crosstalk of estradiol and progesterone with Myeloid-derived suppressor cells and Th1/Th2 cytokines in early miscarriage is associated with early breakdown of maternal-fetal tolerance.

PROBLEM: Decline in myeloid-derived suppressor cells (MDSCs) and Th2 cytokines levels lead to early miscarriage (EM) but how the hormonal milieu of the body regulates MDSCs and Th1/Th2 cytokine balance is still a matter of investigation. METHOD OF STUDY: Peripheral blood and decidua samples were collected from 20 EM patients, and 20 healthy pregnant women opted for elective abortion. MDSCs and G-MDSCs levels were analyzed in peripheral blood mononuclear cells, and Th1/Th2 cytokines levels were determined in serum via flow cytometry. Estrogen (E2), Progesterone (P4), and Testosterone levels were measured via ELISA. Further, proliferation and apoptosis in decidual samples were checked via immunoblot/immunohistochemistry of estrogen receptor -α (ER-α), STAT-3/pSTAT-3, and caspase-3, respectively. RESULTS: Our results clearly indicate that in EM patients; decline in E2 and P4 significantly correlates with decline in MDSCs, particularly with subtype granulocytic MDSCs (G-MDSCs) and skewness of the Th1/Th2 cytokines balance toward Th1 response. Downregulation of ER- α and increased caspase-3 expression in endometrium decidua signifies poor endometrial receptivity in EM. STAT-3 activation regulates proliferation, differentiation and suppressive potency of MDSCs. In decidua of EM, significantly lower expression of pSTAT-3 indicates that these processes pertaining to MDSCs are compromised. CONCLUSION: Altogether, this unfavorable systemic milieu may drive toward early breakdown of maternal-fetal tolerance in EM. Therefore, regulated crosstalk of E2, P4 with MDSCs and balanced Th1/Th2 cytokines is prerequisite for successful pregnancy.

LPS-Challenged Macrophages Release Microvesicles Coated With Histones.

Histones are the protein component of nucleosomes, which are the basic packing unit of chromatin. However, histones are also found in the blood, both as components of nucleosomes leaked out from dead cells, or expelled from neutrophils in the active process of NET formation. Circulating histones contribute to inflammation, and to lethality in sepsis, a hyperinflammatory condition, by interacting with specific receptors, notably toll-like receptor 4 (TLR4). Here, we show that histones are also actively released by LPS-activated macrophages in association with extracellular vesicles. Vesicle-associated histones can be recovered from the plasma of mice with sepsis. Actively released histones are on the outer surface of vesicles and can interact with TLR4. Thus, activated macrophages release histones without dying, at the same time, making their DNA more accessible and communicating to other cells that infection is present.