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BACKGROUND: Drug shortages are a common issue that healthcare systems face and can result in adverse health outcomes for patients requiring inferior alternate treatment. The United States recently experienced a national drug shortage of intravenous immunoglobulin (IVIG). Several reported strategies to address the IVIG and other drug shortages have been proposed; however, there is a lack of evidence-based methods for protocol development and implementation. OBJECTIVE: To evaluate the efficacy of introducing a multidisciplinary task force and tier system of indications and to minimize adverse effects during a shortage of IVIG. METHODS: Faculty members across disciplines with expertise in IVIG use were invited to participate in a task force to address the shortage and ensure adequate supply for emergent indications. A tier system of IVIG indications was established according to the severity of diagnosis, urgency of indication, and quality of supporting evidence. Based on inventory, indications in selected tiers were auto-approved. Orders that could not be automatically approved were escalated for task force review. RESULTS: Overall, there were 342 distinct requests for IVIG during the study period (August 1, 2019 to December 31, 2019). All Tier 1 indications were approved. Of all requests, only 2.6% (9) of requests were denied, none of which resulted in adverse effects based on retrospective chart review. Seven patients who regularly receive IVIG had possible adverse effects due to dose reduction or spacing of treatment; however, each complication was multifactorial and not attributed to the shortage or tier system implementation alone. CONCLUSION: Implementation of a multidisciplinary task force and tier system to appropriately triage high-priority indications for limited pharmaceutical agents should be considered in health institutions faced with a drug shortage.
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Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Inmunoglobulinas Intravenosas , Niño , Humanos , Inmunoglobulinas Intravenosas/efectos adversos , Estudios Retrospectivos , Atención Terciaria de Salud , Centros de Atención Terciaria , Inyecciones Intravenosas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/tratamiento farmacológicoRESUMEN
OBJECTIVE: To evaluate the clinical impact of an institutional thromboprophylaxis protocol in patients with multisystem inflammatory syndrome in children (MIS-C), who are at increased risk for thromboembolism (TE). STUDY DESIGN: We conducted a single-center retrospective cohort study of children less than 18 years between March 2020 and December 2021. Eligible patients were confirmed with MIS-C and were managed with a standardized multidisciplinary treatment approach that included a thromboprophylaxis protocol to guide and unify clinical practice. For high-risk patients, prophylactic dose enoxaparin (target anti-Factor Xa 0.1-0.3 U/mL) was added. In high-risk patients with TE risk factors persistent at hospital discharge, thromboprophylaxis was prescribed for an additional 30 days. RESULTS: Of 135 patients with MIS-C, 124 (92%) required intensive care unit stay and 64 (47%) required a central venous catheter for a median duration of 5 days (IQR, 4-7). Prophylactic dose enoxaparin was initiated in 116 out of 121 patients (96%) deemed high-risk per our protocol at a median of 1 day after admission [IQR, 0-3] achieving target levels at a median of 1 day [IQR, 1-2]. The median initial anti-Factor Xa level was 0.13 u/mL [IQR, 0.05-0.19]. One patient (0.7%) developed symptomatic noncatheter related superficial vein thrombosis requiring therapeutic anticoagulation. Thromboprophylaxis was extended for 30 days after discharge in 108 out of 135 patients (80%). Bleeding events occurred in 5 patients during hospitalization (4.2%). All bleeding events were clinically relevant nonmajor bleeding. There were no deaths. CONCLUSIONS: Implementation of an institutional standardized thromboprophylaxis protocol in MIS-C was feasible and led to timely initiation of prophylactic anticoagulation and low rates of TEs and bleeding complications.
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Enoxaparina , Tromboembolia Venosa , Niño , Humanos , Enoxaparina/uso terapéutico , Anticoagulantes/uso terapéutico , Estudios Retrospectivos , Tromboembolia Venosa/tratamiento farmacológico , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & control , Hemorragia/inducido químicamente , Hemorragia/complicacionesRESUMEN
OBJECTIVE: To determine the prevalence of and risk factors for cerebral sinus venous thrombosis (CSVT) in neonates undergoing congenital heart disease (CHD) repair. STUDY DESIGN: Neonates who had CHD repair with cardiopulmonary bypass and postoperative brain magnetic resonance imaging (MRI) between 2013 and 2019 at a single tertiary care center were identified from institutional databases. Demographic, clinical, and surgical data were abstracted from these databases and from the medical record; 278 neonates with CHD had cardiopulmonary bypass, 184 of whom had a postoperative brain MRI. RESULTS: Eight patients (4.3%) had a CSVT. Transposition of the great arteries with an intact ventricular septum (P < .01) and interrupted aortic arch (P = .02) were associated with an increased risk for CSVT. Other risk factors for CSVT included cross-clamp time (98 [IQR, 77.5-120] minutes vs 67 [IQR, 44-102] minutes; P = .03), units of platelets (3.63 [IQR, 3-4] vs 2.17 [IQR, 1-4]; P < .01) and packed red blood cells (0.81 [IQR, 0.25-1] vs 1.21 [IQR, 1-1]; P = .03) transfused intraoperatively, and time between surgery and MRI (10 [IQR, 7-12.5] days vs 20 [IQR, 12-35] days; P < .01). Five patients (62.5%) were treated with anticoagulation. All patients had complete or partial resolution of their CSVT, regardless of treatment. CONCLUSIONS: Brain MRI after cardiopulmonary bypass in neonates revealed a low prevalence of CSVT (4.3%). Further studies are needed to establish best practices for surveillance, prevention, and treatment of CSVT in this population.
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Cardiopatías Congénitas , Trombosis de los Senos Intracraneales , Transposición de los Grandes Vasos , Trombosis de la Vena , Anticoagulantes/uso terapéutico , Cardiopatías Congénitas/complicaciones , Humanos , Lactante , Recién Nacido , Trombosis de los Senos Intracraneales/epidemiología , Trombosis de los Senos Intracraneales/etiología , Transposición de los Grandes Vasos/complicaciones , Trombosis de la Vena/complicacionesRESUMEN
BACKGROUND: Patients with sickle cell disease (SCD) are at increased risk for osteomyelitis (OM). Diagnosis of OM in SCD is challenging as the clinical presentation is similar to a vasoocclusive crisis (VOC) with no diagnostic gold standard. We report characteristics and outcomes of OM in SCD patients treated at our center over 10-year period. DESIGN/METHOD: We conducted a retrospective analysis of patients with SCD who were treated for OM at our center over a 10-year period (2006-2016). Cases were identified utilizing radiology data mining software. Radiology reports and medical charts of potential OM cases were reviewed. RESULTS: Twenty-eight children with SCD were treated for OM at our institution. Patients treated for OM were largely similar to patients treated for a VOC. However, patients treated for OM had significantly higher C-reactive protein (10 mg/dL vs 5.58 mg/dL, P = 0.03) and erythrocyte sedimentation rate (60 mm/h vs 47 mm/h, P = 0.02). Magnetic resonance imaging (MRI) findings were consistent with OM in 18 (64%) patients and indeterminate in the remaining. Based on clinical, laboratory, and radiological findings, the diagnosis of OM was considered confirmed in 3 patients, probable in 6 patients, and presumed in 19 patients. Nontyphoidal Salmonella was isolated from cultures in 9 (32%) patients, while no organism was identified in 19 (67%) patients. All patients were treated with antibiotics. Six patients (21%) required surgical interventions. CONCLUSIONS: OM continues to pose diagnostic challenges. Most patients are treated for OM without definitive confirmation. Nontyphoidal Salmonella was the only organism identified in our cohort.
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Anemia de Células Falciformes , Imagen por Resonancia Magnética , Osteomielitis , Infecciones por Salmonella , Salmonella/aislamiento & purificación , Adolescente , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/tratamiento farmacológico , Niño , Preescolar , Femenino , Humanos , Masculino , Osteomielitis/tratamiento farmacológico , Osteomielitis/etiología , Osteomielitis/microbiología , Estudios Retrospectivos , Salmonella/clasificación , Infecciones por Salmonella/tratamiento farmacológico , Infecciones por Salmonella/etiología , Infecciones por Salmonella/microbiologíaRESUMEN
OBJECTIVES: Critically ill children with cardiac disease are at significant risk for hospital-associated venous thromboembolism, which is associated with increased morbidity, hospital length of stay, and cost. Currently, there are no widely accepted guidelines for prevention of hospital-associated venous thromboembolism in pediatrics. We aimed to develop a predictive algorithm for identifying critically ill children with cardiac disease who are at increased risk for hospital-associated venous thromboembolism as a first step to reducing hospital-associated venous thromboembolism in this population. DESIGN: This is a prospective observational single-center study. SETTING: Tertiary care referral children's hospital cardiac ICU. PATIENTS: Children less than or equal to18 years old admitted to the cardiac ICU who developed a hospital-associated venous thromboembolism from December 2013 to June 2017 were included. Odds ratios and 95% CIs are reported for multivariable predictors. MEASUREMENTS AND MAIN RESULTS: A total of 2,204 separate cardiac ICU encounters were evaluated with 56 hospital-associated venous thromboembolisms identified in 52 unique patients, yielding an overall prevalence of 25 hospital-associated venous thromboembolism per 1,000 cardiac ICU encounters. We were able to create a predictive algorithm with good internal validity that performs well at predicting hospital-associated venous thromboembolism. The presence of a central venous catheter (odds ratio, 4.76; 95% CI, 2.0-11.1), sepsis (odds ratio, 3.5; 95% CI, 1.5-8.0), single ventricle disease (odds ratio, 2.2; 95% CI, 1.2-3.9), and extracorporeal membrane oxygenation support (odds ratio, 2.7; 95% CI, 1.2-5.7) were independent risk factors for hospital-associated venous thromboembolism. Encounters with hospital-associated venous thromboembolism were associated with a higher rate of stroke (17% vs 1.2%; p < 0.001). CONCLUSIONS: We developed a multivariable predictive algorithm to help identify children who may be at high risk of hospital-associated venous thromboembolism in the pediatric cardiac ICU.
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Algoritmos , Tromboembolia Venosa , Adolescente , Niño , Hospitales , Humanos , Lactante , Estudios Prospectivos , Estudios Retrospectivos , Factores de Riesgo , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiología , Tromboembolia Venosa/etiologíaRESUMEN
We describe a 2-year-old girl with bow hunter syndrome complicated by vertebral artery dissection and multiple ischemic infarcts. Pediatric bow hunter syndrome is a rare and likely under-recognized disorder. Interestingly, our patient had atlanto-occipital ligament calcification on CT scan, an imaging finding that has not been reported in association with bow hunter syndrome and one that might help increase recognition of this dynamic disorder of the posterior circulation.
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Arteriopatías Oclusivas/diagnóstico por imagen , Articulación Atlantooccipital/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Artropatías/diagnóstico por imagen , Ligamentos Articulares/diagnóstico por imagen , Arteria Vertebral/diagnóstico por imagen , Arteriopatías Oclusivas/complicaciones , Arteriopatías Oclusivas/etiología , Articulación Atlantooccipital/patología , Preescolar , Angiografía por Tomografía Computarizada/métodos , Femenino , Humanos , Artropatías/complicaciones , Artropatías/patología , Ligamentos Articulares/patología , Angiografía por Resonancia Magnética/métodos , Arteria Vertebral/patología , Disección de la Arteria Vertebral/diagnóstico por imagen , Disección de la Arteria Vertebral/etiologíaRESUMEN
OBJECTIVE: To describe the incidence and characteristics of central venous catheter (CVC)-related thrombosis in hospitalized pediatric patients with active inflammatory bowel disease (IBD) and report the potential usefulness of anticoagulant thromboprophylaxis (AT). STUDY DESIGN: We conducted a retrospective study of patients who were admitted to our children's hospital in the last 2 years with active IBD and required a CVC and identified all patients with an objectively confirmed symptomatic CVC-related thrombosis. To assess the usefulness of a recently implemented institutional AT protocol, we compared the frequency of CVC-related thrombosis, nadir hemoglobin, and red blood cell transfusion requirements in patients who received AT with those who did not during the study period. RESULTS: A total of 40 patients with IBD who required 47 consecutive hospitalizations were included. AT was administered during 24 of 47 hospitalizations (51%). Patients who received AT were similar to those who did not receive AT with regard to demographics, IBD phenotypes, extent of colonic involvement, and thrombotic risk factors. CVC-related thrombosis occurred in 5 of 23 hospitalizations (22%) in which AT was withheld compared with 0 of 24 hospitalizations (0%) in which patients received AT (P = .02). The red blood cell transfusion requirements and nadir hemoglobin were not significantly different between the 2 groups. CONCLUSIONS: We observed a high incidence of CVC-related thrombosis in hospitalized children with IBD. Administration of AT in our population was associated with significant reduction in CVC-related thrombosis without evidence of increased bleeding.
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Anticoagulantes/uso terapéutico , Cateterismo Venoso Central/efectos adversos , Catéteres Venosos Centrales/efectos adversos , Enoxaparina/uso terapéutico , Enfermedades Inflamatorias del Intestino/terapia , Trombosis de la Vena/epidemiología , Adolescente , Niño , Femenino , Hospitalización , Humanos , Incidencia , Masculino , Estudios Retrospectivos , Trombosis de la Vena/prevención & controlAsunto(s)
Ataque Isquémico Transitorio , Lupus Eritematoso Sistémico , Vasculitis por Lupus del Sistema Nervioso Central , Estudios de Casos y Controles , Sistema Nervioso Central , Humanos , Ataque Isquémico Transitorio/etiología , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnósticoRESUMEN
OBJECTIVE: Subcutaneous enoxaparin is the mainstay anticoagulant in critically ill pediatric patients although it poses several challenges in this patient population. Enoxaparin infused IV over 30 minutes represents an attractive alternative, but there is limited experience with this route of administration in children. In this study, we assess dosing, anticoagulation quality, safety, and clinical efficacy of IV enoxaparin compared to subcutaneous enoxaparin in critically ill infants and children. DESIGN: Retrospective single-center study comparing dosing, anticoagulation quality, safety, and clinical efficacy of two different routes of enoxaparin administration (IV vs subcutaneous) in critically ill infants and children. Key outcome measures included dose needed to achieve target antifactor Xa levels, time required to achieve target antifactor Xa levels, proportion of patients achieving target anticoagulation levels on initial dosing, number of dose adjustments, duration spent in the target antifactor Xa range, anticoagulation-related bleeding complications, anticoagulation failure, and radiologic response to anticoagulation. SETTING: Tertiary care pediatric hospital. PATIENTS: All children admitted to the cardiac ICU, PICU, or neonatal ICU who were prescribed enoxaparin between January 2014 and March 2016 were studied. INTERVENTIONS: One hundred ten patients were identified who had received IV or subcutaneous enoxaparin and had at least one postadministration peak antifactor Xa level documented. MEASUREMENTS AND MAIN RESULTS: Of the 139 courses of enoxaparin administered, 96 were therapeutic dose courses (40 IV and 56 subcutaneous) and 43 were prophylactic dose courses (20 IV and 23 subcutaneous). Dosing, anticoagulation quality measurements, safety, and clinical efficacy were not significantly different between the two groups. CONCLUSIONS: Our study suggests that anticoagulation with IV enoxaparin infused over 30 minutes is a safe and an equally effective alternative to subcutaneous enoxaparin in critically ill infants and children.
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Anticoagulantes/administración & dosificación , Enoxaparina/administración & dosificación , Tromboembolia/prevención & control , Anticoagulantes/uso terapéutico , Niño , Preescolar , Protocolos Clínicos , Enfermedad Crítica , Esquema de Medicación , Enoxaparina/uso terapéutico , Femenino , Estudios de Seguimiento , Humanos , Lactante , Infusiones Intravenosas , Inyecciones Subcutáneas , Masculino , Seguridad del Paciente , Estudios Retrospectivos , Tromboembolia/tratamiento farmacológico , Resultado del TratamientoRESUMEN
Arterial ischemic strokes (AIS) localized solely to the midbrain are extremely uncommon in the pediatric population. Elevated lipoprotein (a), which promotes atherosclerosis and a prothrombotic state, has been associated with increased risk of AIS in children and adults. Here we describe a 17-year-old boy and a 15-year-old girl who presented with internuclear ophthalmoplegia secondary to an isolated midbrain AIS. Evaluation for risk factors for AIS in these otherwise healthy adolescents identified hyperlipoproteinemia (a) in combination with other potential prothrombotic conditions suggesting that hypercoagulable states such as hyperlipoproteinemia (a) may have contributed to development of small-vessel arteriopathy and localized AIS.
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Infarto Cerebral/sangre , Hiperlipoproteinemias/etiología , Lipoproteína(a)/sangre , Adolescente , Femenino , Humanos , Masculino , Deficiencia de Proteína S/etiologíaRESUMEN
BACKGROUND: The safety profile of anticoagulants, which are being used with increasing frequency in pediatric populations, is not well studied. Automatic triggers built into electronic health record systems (EHR) have been shown to be an effective way to monitor for and identify medication errors. Anticoagulant-associated adverse events were examined through the use of an anticoagulant trigger panel. METHODS: In a retrospective, five-year (September 2007-September 2012) observational study, four automated triggers were used to detect anticoagulant-related adverse events: activated partial thromboplastin time (aPTT) > 100 seconds in patients on an unfractionated heparin (UFH) infusion, International Normalized Ratio (INR) > 4, anti-factor Xa (anti-FXa) >1.5U/mL for patients on enoxaparin, and the documented use of protamine. RESULTS: For the 1,664 triggers evaluated, 12 were associated with the aPTT trigger, only 1 of which was preventable. Receiver operator characteristic curve analysis indicated that increasing the aPTT trigger > 140 seconds would optimize sensitivity and specificity. The INR trigger identified four outpatients with adverse events. No adverse events were associated with the anti-FXa trigger. The protamine trigger identified 12 adverse events and was associated with more severe events. Minimal overlap was found with protamine and aPTT triggers. CONCLUSION: Laboratory- and medication-based triggers can be effective monitoring tools for anticoagulants. For patients receiving a UFH infusion, an aPTT cutoff value of > 140 seconds is more precise. We also found that protamine use as a trigger adds value to a trigger-based anticoagulant monitoring system. Continued improvement in the logic algorithms associated with the EHR-based trigger tool will allow expanded use of this tool in a clinical manner.
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Anticoagulantes/efectos adversos , Monitoreo de Drogas/métodos , Registros Electrónicos de Salud/organización & administración , Hospitales Pediátricos/organización & administración , Errores de Medicación/efectos adversos , Humanos , Relación Normalizada Internacional , Tiempo de Tromboplastina Parcial , Calidad de la Atención de Salud , Estudios RetrospectivosRESUMEN
BACKGROUND: Newborns with hypoxic ischemic encephalopathy (HIE) are at risk for coagulopathy due to systemic oxygen deprivation. Additionally, therapeutic hypothermia (TH) slows enzymatic activity of the coagulation cascade, leading to constitutive prolongation of routinely assessed coagulation studies. The level of laboratory abnormality that predicts bleeding is unclear, leading to varying transfusion therapy practices. METHODS: HIE infants treated with TH between 2008-2012 were included in this retrospective study. Initial, minimum (min) and maximum (max) values of International Normalized Ratio (INR), activated partial thromboplastin time (aPTT), fibrinogen (Fib) and platelet (PLT) count (measured twice daily during TH) were collected. Bleeding was defined as clinically significant if associated with 1) decreased hemoglobin (Hb) by 2 g/dL in 24 hours, 2) transfusion of blood products for hemostasis, or 3) involvement of a critical organ system. Laboratory data between the bleeding group (BG) and non-bleeding group (NBG) were compared. Variables that differed significantly between groups were evaluated with Receiver Operating Characteristic Curve (ROC) analyses to determine cut-points to predict bleeding. RESULTS: Laboratory and bleeding data were collected from a total of 76 HIE infants with a mean (±SD) birthweight of 3.34 ± 0.67 kg and gestational age of 38.6 ± 1.9 wks. BG included 41 infants. Bleeding sites were intracranial (n = 13), gastrointestinal (n = 19), pulmonary (n = 18), hematuria (n = 11) or other (n = 1). There were no differences between BG and NBG in baseline characteristics (p > 0.05). Both groups demonstrated INR and aPTT values beyond the acceptable reference ranges utilized for full tem newborns. BG had higher initial and max INR, initial aPTT, and lower min PLT and min Fib compared to NBG. ROC analyses revealed that platelet count <130 × 109/L, fib level <1.5 g/L, and INR >2 discriminated BG from NBG. CONCLUSIONS: Laboratory evidence of coagulopathy is universal in HIE babies undergoing TH. Transfusion strategies to maintain PLT counts >130 × 109/L, fib level >1.5 g/L, and INR <2 may prevent clinical bleeding in this high risk population.
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Hemorragia/etiología , Hipotermia Inducida/efectos adversos , Hipoxia-Isquemia Encefálica/complicaciones , Hipoxia-Isquemia Encefálica/terapia , Transfusión Sanguínea , Estudios de Casos y Controles , Femenino , Fibrinógeno/análisis , Hemorragia/terapia , Humanos , Recién Nacido , Relación Normalizada Internacional , Masculino , Tiempo de Tromboplastina Parcial , Recuento de Plaquetas , Estudios Retrospectivos , Factores de RiesgoRESUMEN
CONTEXT.: Myelodysplastic syndromes (MDSs) are rare in children and have unique clinical manifestations and implications. OBJECTIVE.: To review the clinical features, pathogenesis, and classification of pediatric MDS. DATA SOURCES.: Published literature and personal experience. CONCLUSIONS.: Pediatric MDS vastly differs from adult MDS. Evaluation for the presence of an underlying germline predisposition syndrome is critical for optimal classification and management. Because of the rarity of cases, resources to aid with the recognition, diagnosis, and management of pediatric MDS are limited, and multi-institutional collaborative studies are needed for the future.
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Resuscitation of children and neonates with severe or refractory bleeding due to surgery or trauma often requires massive transfusion (MT). Findings from recent studies have led to a better understanding of the complex pathophysiology in massive haemorrhage and the effects of MT on haemostasis. Current management of the massively bleeding adult patient has evolved over the past few decades, shifting to early transfusion of products in a balanced ratio as part of MT protocols (MTPs). Paediatric data on successful management of MT are limited and the optimal transfusion approach is currently unknown, leading to practice variability among institutions, depending on resource availability and patients' needs. Here, we review new important concepts in the biology of massive bleeding and MT, outline important management principles and current practices, and highlight available relevant adult and paediatric data.
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Transfusión Sanguínea/métodos , Hemorragia/terapia , Transfusión Sanguínea/normas , Niño , Preescolar , Protocolos Clínicos , Hemorragia/fisiopatología , Hemostasis/fisiología , Trastornos Hemostáticos/terapia , Humanos , Lactante , Recién Nacido , Reacción a la TransfusiónAsunto(s)
Aspirina , Plaquetas/metabolismo , Procedimiento de Fontan , Activación Plaquetaria/efectos de los fármacos , Tromboelastografía , Tromboxano B2/análogos & derivados , Aspirina/administración & dosificación , Aspirina/sangre , Aspirina/farmacocinética , Aspirina/orina , Preescolar , Femenino , Humanos , Masculino , Tromboxano B2/orinaRESUMEN
Jacobsen syndrome (JS) is a rare contiguous gene disorder characterized by a deletion within the distal part of the long arm of chromosome 11 ranging in size from 7 to 20 Mb. The clinical findings include characteristic dysmorphic features, growth and psychomotor delays and developmental anomalies involving the brain, eyes, heart, kidneys, immune, hematologic, endocrine, and gastrointestinal systems. The majority of cases are due to a terminal deletion of 11q; however interstitial deletions have also been reported. We report on a child with clinical manifestations consistent with JS who had a 2.899 Mb interstitial deletion at 11q24.2-q24.3 which is the smallest interstitial deletion reported so far to our knowledge. This deletion includes the KIRREL3 gene, and given our patient's history of neurocognitive delay and autism spectrum disorder, it raises the possibility that this gene is a candidate for the social and expressive language delay observed in our patient.
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Proteínas Portadoras/genética , Trastornos Generalizados del Desarrollo Infantil/genética , Deleción Cromosómica , Cromosomas Humanos Par 11/genética , Síndrome de Deleción Distal 11q de Jacobsen/genética , Proteínas de la Membrana/genética , Encéfalo/diagnóstico por imagen , Trastornos Generalizados del Desarrollo Infantil/fisiopatología , Preescolar , Femenino , Humanos , Síndrome de Deleción Distal 11q de Jacobsen/fisiopatología , RadiografíaRESUMEN
BACKGROUND: Intracellular adenosine triphosphate (ATP) levels decline significantly during storage of platelet (PLT) products, in part due to PLT degranulation. However, metabolic ATP stores also become depleted during storage through an unclear mechanism. Since both anaerobic glycolysis and oxidative phosphorylation are important for PLT ATP production, it is possible that the reduction in metabolic ATP reflects impaired oxidative phosphorylation. To assess this, we evaluated the kinetic activity and protein expression of cytochrome C oxidase (CcOX) in stored apheresis PLTs. STUDY DESIGN AND METHODS: Apheresis PLTs were collected and stored with agitation at 22 ± 2°C for 7 days. In vitro measurements of PLT metabolic state, function, and activation were performed on Days 0, 2, 4, and 7 of storage. Total PLT ATP content, steady-state CcOX kinetic activity, and protein immunoblotting for CcOX Subunits I and IV were also performed using isolated PLT mitochondria from simultaneously collected samples. RESULTS: Intra-PLT ATP and steady-state PLT CcOX activity declined significantly and in a progressive manner throughout storage while steady-state levels of CcOX I and IV protein remained unchanged. Time-dependent decline in CcOX activity correlated with progressive ATP depletion over time. CONCLUSION: During storage of apheresis PLTs for 7 days, the parallel decline in CcOX function and intra-PLT ATP suggests development of an acquired impairment in PLT oxidative phosphorylation associated with perturbed ATP homeostasis in stored PLTs.
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Adenosina Trifosfato/metabolismo , Plaquetas/metabolismo , Conservación de la Sangre , Complejo IV de Transporte de Electrones/sangre , Plaquetoferesis , Complejo IV de Transporte de Electrones/fisiología , HumanosRESUMEN
Qualitative platelet disorders remain rare and varied. We describe here 2 additional patients with giant platelets, thrombocytopenia, deficiency in alpha granules and the presence of membranous inclusions within the cytoplasm. Collectively known as Medich syndrome, we further elucidated structural and clinical features of this rare syndrome. Platelets obtained from 2 patients with macro-thrombocytopenia were evaluated by electron microscopy. Structural findings were correlated with clinical characteristics. The defining morphologic feature found in the platelets of these patients is the presence of long, tubular inclusions consisting of several layers of membrane wrapped around a core of cytoplasm. These inclusions may deform the discoid shape of the platelet. In addition, abnormal giant alpha granules are present. Clinically all patients in the current report and review of the literature had mucosal bleeding and were often misdiagnosed as having immune related thrombocytopenia. To date five cases of Medich giant platelet syndrome have been reported. The cases are unified by the ultrastructural findings of abnormal alpha granules and unusual cytoplasmic scrolls. All patients experienced mucosal bleeding, however many clinical, biologic and genetic characteristics of this rare disorder remain to be determined.
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Pulmonary embolism (PE) has long been described in children. Nevertheless, most of the algorithms applied to patients within this age range, from diagnosis to therapy, have been adapted from adult protocols. This article reviews the progresses that occurred to PE in children placing them in historical perspective with the key events relevant to PE in adults. A brief summary of the initial reports encountered in the pediatric literature followed by key conclusions drawn from national database reports characterizing its epidemiology in children is highlighted. Additionally, a section with the diagnostic tools pertaining to children is included. Closing remarks encompass commentaries related to therapy and outcomes, reflecting on current knowledge gaps related to PE in children.