Venous Thromboembolism in Children and Teenagers Admitted for Trauma: A 5-Year Nationwide Perspective.

Venous thromboembolism (VTE) in pediatric trauma patients is under-investigated. The purpose of this study was to perform an evaluation of the risk factors for VTE after pediatric trauma, including readmissions across the United States. The Nationwide Readmissions Database for 2016-2020 was queried for all patients under the age of 18 years admitted for trauma. 276 670 patients were identified; 2063 (.8%) were diagnosed with VTE. Among those with VTE, 300 (15%) were identified during a readmission. Higher rates of VTE were seen in ages 15-17 years (n = 1,294, 1.3%, P < .001), penetrating injuries (n = 478, .9%, P < .001), and assault (n = 271, 2.7%, P < .001). The strongest risk factor for VTE was prolonged mechanical ventilation (OR 5.5 [4.9-6.3] P < .001). Our study found that a significant portion of post-traumatic VTE in children and teenagers occur during readmissions. A deeper understanding of the risk factors outlined here can guide enhanced clinical protocols, ensuring early detection and prevention of this complication.

Optimizing Triage Practice in Pediatric Trauma: Lessons From Under-triage and Over-triage Rates and Risk Factors.

BACKGROUND: Triage accuracy is essential for delivering effective trauma care, especially in the pediatric population where unique challenges exist. The purpose of this study was to investigate risk factors contributing to under-triage and over-triage in an urban pediatric trauma center. METHODS: This retrospective cohort study included all trauma activations at an urban level 1 trauma center between January 1, 2021, and July 31, 2023 (patients <18 years old.) Patients who were under- or over-triaged were identified based on the level of trauma activation and injury severity score. RESULTS: There were 1094 trauma activations included in this study. The rate of under-triage was 3.8% (n = 42) and over-triage was 13.6% (n = 149). Infants aged 0-1 years had the highest rate of under-triage (10.9%, n = 19, P < .001), while those aged 11-17 had the highest rate of over-triage (17.0%, n = 82, P = .003). Non-accidental trauma was the strongest risk factor for under-triage (OR 30.2 [6.4-142.8] P < .001). Penetrating mechanism was the strongest risk factor for over-triage (OR 12.2 [5.6-26.2] P < .001). DISCUSSION: This study reveals the complexity of trauma triage in the pediatric population. We identified key predictive factors, such as age, comorbidities, and mechanism of injury, that can be used to refine triage practices and improve the care of pediatric trauma patients.

Nationwide Propensity-Matched Comparison of Surgical Site Infections in Safety Net Hospitals.

This cohort study examines the rates and risks associated with surgical site infection during admission or readmission of socioeconomically marginalized patients undergoing gastrointestinal surgery.

Chemoembolization Versus Radioembolization for Neuroendocrine Liver Metastases: A Meta-analysis Comparing Clinical Outcomes.

BACKGROUND: Studies have shown intra-arterial therapies to be effective in controlling neuroendocrine liver metastases (NELMs), but the evidence supporting the selection of specific methods is limited. This meta-analysis is the first to compare survival outcomes between transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) in the treatment of NELM. METHODS: A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in PubMed and Embase databases was conducted in February 2020 for published studies comparing survival outcomes between TACE and TARE in the treatment of NELM. RESULTS: Six eligible cohort studies with a total of 643 patients were identified. The TACE and TARE groups were similar in terms of age, sex, hepatic tumor burden, tumor grade, and Eastern Cooperative Oncology Group (ECOG) score. The patients treated with TACE had significantly better overall survival (odds ratio [OR], 1.92; 95% confidence interval [CI] 1.14-3.22, p = 0.014) than those treated with TARE. Overall survival ranged from 16.8 to 81.9 months with TACE and from 14.5 to 66.8 months with TARE. No significant differences in hepatic progression-free survival (OR, 1.01; 95% CI 0.75-1.35; p = 0.96) or tumor response were observed within the first 3 months (OR, 2.87; 95% CI 0.81-10.21; p = 0.10) or thereafter (OR, 0.98; 95% CI 0.12-7.86; p = 0.99). The complication rates were similar between the two groups, with 6.9% of the TACE patients versus 8.5% of TARE patients reporting major complications (OR, 1.16; 95% CI 0.54-2.48; p = 0.71) and respectively 44.6% and 58.8% of the TACE and TARE patients reporting minor adverse events (OR, 1.08; 95% CI 0.39-2.99; p = 0.88). CONCLUSIONS: Despite similar tumor responses, an overall survival benefit was associated with TACE treatment of NELM compared with TARE treatment. Randomized controlled trials are warranted to confirm this finding and clarify whether certain subpopulations benefit from different transarterial methods.

Group B streptococcus exploits vaginal epithelial exfoliation for ascending infection.

Thirteen percent of pregnancies result in preterm birth or stillbirth, accounting for fifteen million preterm births and three and a half million deaths annually. A significant cause of these adverse pregnancy outcomes is in utero infection by vaginal microorganisms. To establish an in utero infection, vaginal microbes enter the uterus by ascending infection; however, the mechanisms by which this occurs are unknown. Using both in vitro and murine models of vaginal colonization and ascending infection, we demonstrate how a vaginal microbe, group B streptococcus (GBS), which is frequently associated with adverse pregnancy outcomes, uses vaginal exfoliation for ascending infection. GBS induces vaginal epithelial exfoliation by activation of integrin and ß-catenin signaling. However, exfoliation did not diminish GBS vaginal colonization as reported for other vaginal microbes. Rather, vaginal exfoliation increased bacterial dissemination and ascending GBS infection, and abrogation of exfoliation reduced ascending infection and improved pregnancy outcomes. Thus, for some vaginal bacteria, exfoliation promotes ascending infection rather than preventing colonization. Our study provides insight into mechanisms of ascending infection by vaginal microbes.

Diminished Capsule Exacerbates Virulence, Blood-Brain Barrier Penetration, Intracellular Persistence, and Antibiotic Evasion of Hyperhemolytic Group B Streptococci.

Group B streptococci (GBS) are encapsulated, ß-hemolytic bacteria that are a common cause of infections in human newborns and certain adults. Two factors important for GBS virulence are the sialic acid capsular polysaccharide that promotes immune evasion and the hemolytic pigment that induces host cell cytotoxcity. These virulence factors are often oppositely regulated by the CovR/CovS two-component system. Clinical GBS strains exhibiting hyperhemolysis and low capsule due to pathoadaptive covR/S mutations have been isolated from patients. Given the importance of capsule to GBS virulence, we predicted that a decrease or loss of capsule would attenuate the virulence of covR/S mutants. Surprisingly, hyperhemolytic GBS with low or no capsule exhibit increased virulence, intracellular persistence, and blood-brain barrier penetration, which was independent of a Trojan horse mechanism of barrier penetration. Additionally, intracellular persistence enabled both hemolytic and hyperhemolytic GBS to evade antibiotics routinely used to treat these infections. The finding that diminished capsule expression promotes GBS virulence, intracellular persistence, and antibiotic evasion has important implications for sustained antibiotic therapy and efficacy of capsule-based vaccines.

Uterine overdistention induces preterm labor mediated by inflammation: observations in pregnant women and nonhuman primates.

OBJECTIVE: Uterine overdistention is thought to induce preterm labor in women with twin and multiple pregnancies, but the pathophysiology remains unclear. We investigated for the first time the pathogenesis of preterm birth associated with rapid uterine distention in a pregnant nonhuman primate model. STUDY DESIGN: A nonhuman primate model of uterine overdistention was created using preterm chronically catheterized pregnant pigtail macaques (Macaca nemestrina) by inflation of intraamniotic balloons (N = 6), which were compared to saline controls (N = 5). Cesarean delivery was performed due to preterm labor or at experimental end. Microarray, quantitative reverse transcriptase polymerase chain reaction, Luminex (Austin, TX), and enzyme-linked immunosorbent assay were used to measure messenger RNA (mRNA) and/or protein levels from monkey (amniotic fluid, myometrium, maternal plasma) and human (amniocytes, amnion, myometrium) tissues. Statistical analysis employed analysis of covariance and Wilcoxon rank sum. Biomechanical forces were calculated using the law of Laplace. RESULTS: Preterm labor occurred in 3 of 6 animals after balloon inflation and correlated with greater balloon volume and uterine wall stress. Significant elevations of inflammatory cytokines and prostaglandins occurred following uterine overdistention in an "inflammatory pulse" that correlated with preterm labor (interleukin [IL]-1ß, tumor necrosis factor [TNF]-α, IL-6, IL-8, CCL2, prostaglandin E2, prostaglandin F2α, all P < .05). A similar inflammatory response was observed in amniocytes in vitro following mechanical stretch (IL1ß, IL6, and IL8 mRNA multiple time points, P < .05), in amnion of women with polyhydramnios (IL6 and TNF mRNA, P < .05) and in amnion (TNF-α) and myometrium of women with twins in early labor (IL6, IL8, CCL2, all P < .05). Genes differentially expressed in the nonhuman primate after balloon inflation and in women with polyhydramnios and twins are involved in tissue remodeling and muscle growth. CONCLUSION: Uterine overdistention by inflation of an intraamniotic balloon is associated with an inflammatory pulse that precedes and correlates with preterm labor. Our results indicate that inflammation is an early event after a mechanical stress on the uterus and leads to preterm labor when the stress is sufficiently great. Further, we find evidence of uterine tissue remodeling and muscle growth as a common, perhaps compensatory, response to uterine distension.

A streptococcal lipid toxin induces membrane permeabilization and pyroptosis leading to fetal injury.

Group B streptococci (GBS) are Gram-positive bacteria that cause infections in utero and in newborns. We recently showed that the GBS pigment is hemolytic and increased pigment production promotes bacterial penetration of human placenta. However, mechanisms utilized by the hemolytic pigment to induce host cell lysis and the consequence on fetal injury are not known. Here, we show that the GBS pigment induces membrane permeability in artificial lipid bilayers and host cells. Membrane defects induced by the GBS pigment trigger K(+) efflux leading to osmotic lysis of red blood cells or pyroptosis in human macrophages. Macrophages lacking the NLRP3 inflammasome recovered from pigment-induced cell damage. In a murine model of in utero infection, hyperpigmented GBS strains induced fetal injury in both an NLRP3 inflammasome-dependent and NLRP3 inflammasome-independent manner. These results demonstrate that the dual mechanism of action of the bacterial pigment/lipid toxin leading to hemolysis or pyroptosis exacerbates fetal injury and suggest that preventing both activities of the hemolytic lipid is likely critical to reduce GBS fetal injury and preterm birth.

The sensor histidine kinase RgfC affects group B streptococcal virulence factor expression independent of its response regulator RgfA.

Group B streptococci (GBS; Streptococcus agalactiae) are beta-hemolytic, Gram-positive bacteria that are common asymptomatic colonizers of healthy adults. However, these opportunistic bacteria also cause invasive infections in human newborns and in certain adult populations. To adapt to the various environments encountered during its disease cycle, GBS encodes a number of two-component signaling systems. Previous studies have indicated that the TCS comprising the sensor histidine kinase RgfC and the response regulator RgfA mediate GBS binding to extracellular matrix components, such as fibrinogen. However, in certain GBS clinical isolates, a point mutation in rgfA results in premature truncation of the response regulator. The truncated RgfA protein lacks the C-terminal DNA binding domain necessary for promoter binding and gene regulation. Here, we show that deletion of rgfC in GBS strains lacking a functional RgfA increased systemic infection. Furthermore, infection with the rgfC mutant increased induction of proinflammatory signaling pathways in vivo. Phosphoproteomic analysis revealed that 19 phosphopeptides corresponding to 12 proteins were differentially phosphorylated at aspartate, cysteine, serine, threonine, or tyrosine residues in the rgfC mutant. This included aspartate phosphorylation of a tyrosine kinase, CpsD, and a transcriptional regulator. Consistent with this observation, microarray analysis of the rgfC mutant indicated that >200 genes showed altered expression compared to the isogenic wild-type strain and included transcriptional regulators, transporters, and genes previously associated with GBS pathogenesis. Our observations suggest that in the absence of RgfA, nonspecific RgfC signaling affects the expression of virulence factors and GBS pathogenesis.

A hemolytic pigment of Group B Streptococcus allows bacterial penetration of human placenta.

Microbial infection of the amniotic fluid is a significant cause of fetal injury, preterm birth, and newborn infections. Group B Streptococcus (GBS) is an important human bacterial pathogen associated with preterm birth, fetal injury, and neonatal mortality. Although GBS has been isolated from amniotic fluid of women in preterm labor, mechanisms of in utero infection remain unknown. Previous studies indicated that GBS are unable to invade human amniotic epithelial cells (hAECs), which represent the last barrier to the amniotic cavity and fetus. We show that GBS invades hAECs and strains lacking the hemolysin repressor CovR/S accelerate amniotic barrier failure and penetrate chorioamniotic membranes in a hemolysin-dependent manner. Clinical GBS isolates obtained from women in preterm labor are hyperhemolytic and some are associated with covR/S mutations. We demonstrate for the first time that hemolytic and cytolytic activity of GBS is due to the ornithine rhamnolipid pigment and not due to a pore-forming protein toxin. Our studies emphasize the importance of the hemolytic GBS pigment in ascending infection and fetal injury.

Hypoxia enhances innate immune activation to Aspergillus fumigatus through cell wall modulation.

Infection by the human fungal pathogen Aspergillus fumigatus induces hypoxic microenvironments within the lung that can alter the course of fungal pathogenesis. How hypoxic microenvironments shape the composition and immune activating potential of the fungal cell wall remains undefined. Herein we demonstrate that hypoxic conditions increase the hyphal cell wall thickness and alter its composition particularly by augmenting total and surface-exposed ß-glucan content. In addition, hypoxia-induced cell wall alterations increase macrophage and neutrophil responsiveness and antifungal activity as judged by inflammatory cytokine production and ability to induce hyphal damage. We observe that these effects are largely dependent on the mammalian ß-glucan receptor dectin-1. In a corticosteroid model of invasive pulmonary aspergillosis, A. fumigatus ß-glucan exposure correlates with the presence of hypoxia in situ. Our data suggest that hypoxia-induced fungal cell wall changes influence the activation of innate effector cells at sites of hyphal tissue invasion, which has potential implications for therapeutic outcomes of invasive pulmonary aspergillosis.