20 research outputs found

    Brucella abortus Induces the Premature Death of Human Neutrophils through the Action of Its Lipopolysaccharide

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    Most bacterial infections induce the activation of polymorphonuclear neutrophils (PMNs), enhance their microbicidal function, and promote the survival of these leukocytes for protracted periods of time. Brucella abortus is a stealthy pathogen that evades innate immunity, barely activates PMNs, and resists the killing mechanisms of these phagocytes. Intriguing clinical signs observed during brucellosis are the low numbers of Brucella infected PMNs in the target organs and neutropenia in a proportion of the patients; features that deserve further attention. Here we demonstrate that B. abortus prematurely kills human PMNs in a dose-dependent and cell-specific manner. Death of PMNs is concomitant with the intracellular Brucella lipopolysaccharide (Br-LPS) release within vacuoles. This molecule and its lipid A reproduce the premature cell death of PMNs, a phenomenon associated to the low production of proinflammatory cytokines. Blocking of CD14 but not TLR4 prevents the Br-LPS-induced cell death. The PMNs cell death departs from necrosis, NETosis and classical apoptosis. The mechanism of PMN cell death is linked to the activation of NADPH-oxidase and a modest but steadily increase of ROS mediators. These effectors generate DNA damage, recruitments of check point kinase 1, caspases 5 and to minor extent of caspase 4, RIP1 and Ca++ release. The production of IL-1β by PMNs was barely stimulated by B. abortus infection or Br-LPS treatment. Likewise, inhibition of caspase 1 did not hamper the Br-LPS induced PMN cell death, suggesting that the inflammasome pathway was not involved. Although activation of caspases 8 and 9 was observed, they did not seem to participate in the initial triggering mechanisms, since inhibition of these caspases scarcely blocked PMN cell death. These findings suggest a mechanism for neutropenia in chronic brucellosis and reveal a novel Brucella-host cross-talk through which B. abortus is able to hinder the innate function of PMN.Fondo Especial de la Educación Superior/[0500-13]/FEES/Costa RicaFondo Especial de la Educación Superior/[0504-13]/FEES/Costa RicaFondo Especial de la Educación Superior/[0505-13]/FEES/Costa RicaFondo Especial de la Educación Superior/[0248-13]/FEES/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

    Firearm injuries in children: a missed opportunity for firearm safety education.

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    BackgroundSurgeons frequently care for children who have sustained gunshot wounds (GSWs). However, firearm safety education is not a focus in general surgery training. We hypothesised that firearm safety discussions do not routinely take place when children present to a trauma centre with a GSW.MethodA retrospective review of patients <18 years presenting with GSWs to a level 1 paediatric trauma centre from 2009 to 2019 was performed. The primary outcome was discussion of firearm safety with the patient or family. The secondary outcome was notification of child protective services (CPS).ResultsA total of 226 patients with GSWs were identified, 22% were unintentional and 63% were assault. Firearm safety discussions took place in 10 cases (4.4%). Firearm safety discussions were more likely to occur after unintentional injuries compared with other mechanisms (16.0% vs 1.3%, p<0.001). CPS was contacted in 29 cases (13%). CPS notification was more likely for unintentional injuries compared with other mechanisms (40% vs 3.9%, p<0.001) and for younger patients (7 years vs 15 years, p<0.001).ConclusionAt a paediatric trauma centre, firearm safety discussions occurred in 4.4% of cases of children presenting with a GSW. There is a significant room for improvement in providing safety education interventions

    Traumatic tension chylothorax in a child: A case report

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    Blunt trauma is the leading cause of death of children and adolescents in the United States. Potentially life-threatening injuries from blunt trauma to the chest must be identified and treated immediately. Clinician familiarity with the range of possible injuries assists in timely diagnosis and therapy. Chylothorax from injury to the thoracic duct is a rare consequence of blunt chest trauma. Tension chylothorax is exceptionally rare. We present a case of a 22-month old boy found to have a traumatic tension chylothorax during initial evaluation in the resuscitation bay after transfer from another facility. There have been no previous reports of a pediatric tension chylothorax after blunt trauma. Management consisted of drainage with tube thoracostomy, parenteral nutrition, and octreotide until the chyle leak resolved. Surgical ligation of the thoracic duct was not required

    Acute Medical Diagnoses Are Common in “Found Down” Adult Patients Presenting to the Emergency Department as Trauma

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    BackgroundPatients often present to the emergency department (ED) as "found down," with limited history to suggest a primary traumatic or medical etiology.ObjectiveThe study objective was to describe the characteristics of "found down" adult patients presenting to the ED as trauma, specifically the incidence of acute medical diagnoses and major trauma.MethodsUsing an institutional trauma registry, we reviewed trauma activations with the cause of injury "found down" between January 2008 and December 2012. We excluded patients with cardiac arrest, transfers from other hospitals, and patients with a more than likely (>50%) traumatic or medical etiology on initial ED presentation. Inclusion and exclusion criteria were reviewed by two independent abstractors. We abstracted demographic, clinical, injury severity, and outcomes variables. Major trauma was defined as Injury Severity Score ≥ 16.ResultsThere were 659 patients identified with the cause of injury "found down." A total of 207 (31%) patients met inclusion criteria; median age was 67 years (interquartile range 50-82 years), and 110 (53%) were male. Among the included patients, 137 (66%, 95% confidence interval [Cl] 59-73%) had a discharge diagnosis of an acute medical condition, 14 (7%, 95% Cl 4-11%) with major trauma alone, 21 (10%, 95% Cl 6-15) with both an acute medical condition and major trauma, and 35 (17%, 95% Cl 12-23%) with minor trauma. The most common acute medical diagnoses were toxicological (56 patients, 35%; 95% Cl 28-43%) and infectious (32 patients, 20%; 95% Cl 14-27%).ConclusionAcute medical diagnoses were common in undifferentiated ED patients "found down" in an institutional trauma registry. Clinicians should maintain a broad differential diagnosis in the workup of the undifferentiated "found down" patient
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