Infants with congenital heart disease are at risk of brain injury and impaired neurodevelopment. The aim was to investigate risk factors for perioperative brain lesions in infants with congenital ...heart disease.
Infants with transposition of the great arteries, single ventricle physiology, and left ventricular outflow tract and/or aortic arch obstruction undergoing cardiac surgery <6 weeks after birth from 3 European cohorts (Utrecht, Zurich, and London) were combined. Brain lesions were scored on preoperative (transposition of the great arteries N=104; single ventricle physiology N=35; and left ventricular outflow tract and/or aortic arch obstruction N=41) and postoperative (transposition of the great arteries N=88; single ventricle physiology N=28; and left ventricular outflow tract and/or aortic arch obstruction N=30) magnetic resonance imaging for risk factor analysis of arterial ischemic stroke, cerebral sinus venous thrombosis, and white matter injury.
Preoperatively, induced vaginal delivery (odds ratio OR, 2.23 95% CI, 1.06-4.70) was associated with white matter injury and balloon atrial septostomy increased the risk of white matter injury (OR, 2.51 95% CI, 1.23-5.20) and arterial ischemic stroke (OR, 4.49 95% CI, 1.20-21.49). Postoperatively, younger postnatal age at surgery (OR, 1.18 95% CI, 1.05-1.33) and selective cerebral perfusion, particularly at ≤20 °C (OR, 13.46 95% CI, 3.58-67.10), were associated with new arterial ischemic stroke. Single ventricle physiology was associated with new white matter injury (OR, 2.88 95% CI, 1.20-6.95) and transposition of the great arteries with new cerebral sinus venous thrombosis (OR, 13.47 95% CI, 2.28-95.66). Delayed sternal closure (OR, 3.47 95% CI, 1.08-13.06) and lower intraoperative temperatures (OR, 1.22 95% CI, 1.07-1.36) also increased the risk of new cerebral sinus venous thrombosis.
Delivery planning and surgery timing may be modifiable risk factors that allow personalized treatment to minimize the risk of perioperative brain injury in severe congenital heart disease. Further research is needed to optimize cerebral perfusion techniques for neonatal surgery and to confirm the relationship between cerebral sinus venous thrombosis and perioperative risk factors.
To examine the relationship between perioperative brain injury and neurodevelopment during early childhood in patients with severe congenital heart disease (CHD).
One hundred and seventy children ...with CHD and born at term who required cardiopulmonary bypass surgery in the first 6 weeks after birth were recruited from 3 European centers and underwent preoperative and postoperative brain MRIs. Uniform description of imaging findings was performed and an overall brain injury score was created, based on the sum of the worst preoperative or postoperative brain injury subscores. Motor and cognitive outcomes were assessed with the Bayley Scales of Infant and Toddler Development Third Edition at 12 to 30 months of age. The relationship between brain injury score and clinical outcome was assessed using multiple linear regression analysis, adjusting for CHD severity, length of hospital stay (LOS), socioeconomic status (SES), and age at follow-up.
Neither the overall brain injury score nor any of the brain injury subscores correlated with motor or cognitive outcome. The number of preoperative white matter lesions was significantly associated with gross motor outcome after correction for multiple testing (P = .013, β = −0.50). SES was independently associated with cognitive outcome (P < .001, β = 0.26), and LOS with motor outcome (P < .001, β = −0.35).
Preoperative white matter lesions appear to be the most predictive MRI marker for adverse early childhood gross motor outcome in this large European cohort of infants with severe CHD. LOS as a marker of disease severity, and SES influence outcome and future intervention trials need to address these risk factors.
Nanoparticle transport across cell membrane plays a crucial role in the development of drug delivery systems as well as in the toxicity response induced by nanoparticles. As hydrophilic nanoparticles ...interact with lipid membranes and are able to induce membrane perturbations, hypothetic mechanisms based on membrane curvature or hole formation have been proposed for activating their transmigration. We report on the transport of hydrophilic silica nanoparticles into large unilamellar neutral DOPC liposomes via an internalization process. The strong adhesive interactions of lipid membrane onto the silica nanoparticle triggered liposome deformation until the formation of a curved neck. Then the rupture of this membrane neck led to the complete engulfment of the nanoparticle. Using cryo-electron tomography we determined 3D architectures of intermediate steps of this process unveiling internalized silica nanoparticles surrounded by a supported lipid bilayer. This engulfing process was achieved for a large range of particle size (from 30 to 200
nm in diameter). These original data provide interesting highlights for nanoparticle transmigration and could be applied to biotechnology development.
The aim of this study was to evaluate postoperative indices of cerebral oxygenation and autoregulation in infants with critical congenital heart disease in relation to new postoperative ischemic ...brain injury.
This prospective, clinical cohort included 77 infants with transposition of the great arteries (N = 19), left ventricular outflow tract obstruction (N = 30), and single ventricle physiology (N = 28) undergoing surgery at 30 days or less of life. Postoperative near-infrared spectroscopy and physiologic monitoring were applied to extract mean arterial blood pressure, regional cerebral oxygen saturation, fractional tissue oxygen extraction, and regional cerebral oxygen saturation mean arterial blood pressure correlation coefficient (≥0.5 considered sign of impaired cerebral autoregulation). New postoperative ischemic injury was defined as moderate-severe white matter injury or focal infarction on magnetic resonance imaging. Low cardiac output syndrome was measured as lactate greater than 4 mmol/L with pH less than 7.30.
After surgery, regional cerebral oxygen saturation was decreased in all congenital heart disease groups with a notable increase in regional cerebral oxygen saturation between 6 and 12 hours after surgery, on average with a factor of 1.4 (range, 1.1-2.4). Both single ventricle physiology and postoperative low cardiac output syndrome were associated with lower regional cerebral oxygen saturation and increased time with correlation coefficient of 0.5 or greater. New postoperative ischemic injury was seen in 39 patients (53%) and equally distributed across congenital heart disease groups. Postoperative regional cerebral oxygen saturation, fractional tissue oxygen extraction, and correlation coefficient were not independently associated with new postoperative white matter injury or focal infarction (mixed-model analysis, all F > 0.12).
Postoperative indices of cerebral oxygenation and cerebral autoregulation are not independent predictors of new ischemic brain injury in infants with critical congenital heart disease. Further exploration of the complex interplay among low regional cerebral oxygen saturation, low cardiac output syndrome, and heart defect is required to identify potential biomarkers enabling early intervention for ischemic brain injury.
To study perioperative amplitude-integrated electroencephalography (aEEG) as an early marker for new brain injury in neonates requiring cardiac surgery for critical congenital heart disease (CHD).
...This retrospective observational cohort study investigated 76 neonates with critical CHD who underwent neonatal surgery. Perioperative aEEG recordings were evaluated for background pattern (BGP), sleep-wake cycling (SWC), and ictal discharges. Spontaneous activity transient (SAT) rate, inter-SAT interval (ISI), and percentage of time with an amplitude <5 µV were calculated. Routinely obtained preoperative and postoperative magnetic resonance imaging of the brain were reviewed for brain injury (moderate-severe white matter injury, stroke, intraparenchymal hemorrhage, or cerebral sinovenous thrombosis).
Preoperatively, none of the neonates showed an abnormal BGP (burst suppression or worse) or ictal discharges. Postoperatively, abnormal BGP was seen in 18 neonates (24%; 95% CI, 14%-33%) and ictal discharges was seen in 13 neonates (17%; 95% CI, 8%-26%). Abnormal BGP and ictal discharges were more frequent in neonates with new postoperative brain injury (P = .08 and .01, respectively). Abnormal brain activity (ie, abnormal BGP or ictal discharges) was the single risk factor associated with new postoperative brain injury in multivariable logistic regression analysis (OR, 4.0; 95% CI, 1.3-12.3; P = .02). Postoperative SAT rate, ISI, or time <5 µV were not associated with new brain injury.
Abnormal brain activity is an early, bedside marker of new brain injury in neonates undergoing cardiac surgery. Not only ictal discharges, but also abnormal BGP, should be considered a clear sign of underlying brain pathology.
Toxoplasma gondii belongs to the phylum Apicomplexa and is an important cause of congenital disease and infection in immunocompromised patients. Like most apicomplexans, T. gondii possesses several ...plant-like features, such as the chloroplast-like organelle, the apicoplast. We describe and characterize a novel organelle in T. gondii tachyzoites, which is visible by light microscopy and possesses a broad similarity to the plant vacuole. Electron tomography shows the interaction of this vacuole with other organelles. The presence of a plant-like vacuolar proton pyrophosphatase (TgVP1), a vacuolar proton ATPase, a cathepsin L-like protease (TgCPL), an aquaporin (TgAQP1), as well as Ca²⁺/H⁺ and Na⁺/H⁺ exchange activities, supports similarity to the plant vacuole. Biochemical characterization of TgVP1 in enriched fractions shows a functional similarity to the respective plant enzyme. The organelle is a Ca²⁺ store and appears to have protective effects against salt stress potentially linked to its sodium transport activity. In intracellular parasites, the organelle fragments, with some markers colocalizing with the late endosomal marker, Rab7, suggesting its involvement with the endocytic pathway. Studies on the characterization of this novel organelle will be relevant to the identification of novel targets for chemotherapy against T. gondii and other apicomplexan parasites as well.
Surgical treatment of critical aortic coarctation (CoA) is difficult in very low birth weight (VLBW) infants ≤1500 g and preferably postponed until 3 kg with prostaglandins (PGE).
To investigate the ...procedure and outcome of primary coronary stent implantation as bridging therapy to surgery in VLBW infants with CoA.
Retrospective evaluation of primary CoA stenting in VLBW infants from 2010 to 2015.
Five VLBW infants with a median gestational age of 29 weeks (27–32) underwent primary CoA stenting. Indication was cardiac failure in 4 and severe hypertension in 1 patient. Age and weight at intervention were 14 days (range 12–16) and 1200 g (680–1380), respectively. Stent diameter ranged 3–5 mm. The femoral artery used for intervention was occluded in all infants without clinical compromise. Severe restenosis and aneurysm occurred in 1 VLBW infant and was successfully treated with covered coronary stents. Median age at surgical correction was 200 days (111–804) and weight 5500 g (4500–11,400). No reinterventions were required during a median postoperative follow-up of 2.8 years (0.1–5.0). Neurodevelopmental outcomes were normal and comparable between patients and siblings (4/5 gemelli).
Primary coronary stent implantation in VLBW infants with critical CoA is a feasible bridging therapy to surgery.
•Stent implantation is feasible in VLBW infants with critical aortic coarctation.•Primary stent implantation offers a significant bridging-to-surgery interval.•This two-step strategy resulted in lower rates of mortality and recoarctation.
Neonates with congenital heart disease may have an increased risk of cerebral sinovenous thrombosis, but incidence rates are lacking. This study describes the clinical and neuroimaging ...characteristics of cerebral sinovenous thrombosis in neonates undergoing cardiac surgery.
Forty neonates (78% male) requiring neonatal univentricular or biventricular cardiac repair using cardiopulmonary bypass were included. All underwent preoperative (median postnatal day 7) and postoperative (median postoperative day 7) magnetic resonance imaging of the brain, including venography, to detect cerebral sinovenous thrombosis. Clinical characteristics were compared between cerebral sinovenous thrombosis positive and cerebral sinovenous thrombosis negative neonates.
Postoperatively, cerebral sinovenous thrombosis was diagnosed in 11 neonates (28%), with the transverse sinus affected in all, and involvement of multiple sinuses in 10 (91%). Preoperatively, signs of thrombosis were seen in 3 cases (8%). Focal infarction of the basal ganglia was significantly more common in cerebral sinovenous thrombosis positive than cerebral sinovenous thrombosis negative neonates (P = .025). Cerebral sinovenous thrombosis positive neonates spent more time in the intensive care unit preoperatively (P = .001), had lower weight (P = .024) and lower postmenstrual age (P = .030) at surgery, and had prolonged use of a central venous catheter (P = .023) and a catheter placed in the internal jugular vein more often (P = .039). Surgical and postoperative factors were not different between new postoperative cerebral sinovenous thrombosis positive and cerebral sinovenous thrombosis negative neonates.
Cerebral sinovenous thrombosis might be more common than previously understood in neonates undergoing cardiac surgery. In our study, cerebral sinovenous thrombosis was associated with a higher risk of additional intra-parenchymal brain injury.
The entry of enveloped viruses into cells requires the fusion of viral and cellular membranes, driven by conformational changes in viral glycoproteins. Many studies have shown that fusion involves ...the cooperative action of a large number of these glycoproteins, but the underlying mechanisms are unknown. We used electron microscopy and tomography to study the low pH—induced fusion reaction catalyzed by vesicular stomatitis virus glycoprotein (G). Pre- and post-fusion crystal structures were observed on virions at high and low pH, respectively. Individual fusion events with liposomes were also visualized. Fusion appears to be driven by two successive structural rearrangements of G at different sites on the virion. Fusion is initiated at the flat base of the particle. Glycoproteins located outside the contact zone between virions and liposomes then reorganize into regular arrays. We suggest that the formation of these arrays, which have been shown to be an intrinsic property of the G ectodomain, induces membrane constraints, achieving the fusion reaction.
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