Hans J. S. Vles

Cerebral inflammation and mobilization of the peripheral immune system following global hypoxia-ischemia in preterm sheep

BackgroundHypoxic-ischemic encephalopathy (HIE) is one of the most important causes of brain injury in preterm infants. Preterm HIE is predominantly caused by global hypoxia-ischemia (HI). In contrast, focal ischemia is most common in the adult brain and known to result in cerebral inflammation and activation of the peripheral immune system. These inflammatory responses are considered to play an important role in the adverse outcomes following brain ischemia. In this study, we hypothesize that cerebral and peripheral immune activation is also involved in preterm brain injury after global HI.MethodsPreterm instrumented fetal sheep were exposed to 25 minutes of umbilical cord occlusion (UCO) (n = 8) at 0.7 gestation. Sham-treated animals (n = 8) were used as a control group. Brain sections were stained for ionized calcium binding adaptor molecule 1 (IBA-1) to investigate microglial proliferation and activation. The peripheral immune system was studied by assessment of circulating white blood cell counts, cellular changes of the spleen and influx of peripheral immune cells (MPO-positive neutrophils) into the brain. Pre-oligodendrocytes (preOLs) and myelin basic protein (MBP) were detected to determine white matter injury. Electro-encephalography (EEG) was recorded to assess functional impairment by interburst interval (IBI) length analysis.ResultsGlobal HI resulted in profound activation and proliferation of microglia in the hippocampus, periventricular and subcortical white matter. In addition, non-preferential mobilization of white blood cells into the circulation was observed within 1 day after global HI and a significant influx of neutrophils into the brain was detected 7 days after the global HI insult. Furthermore, global HI resulted in marked involution of the spleen, which could not be explained by increased splenic apoptosis. In concordance with cerebral inflammation, global HI induced severe brain atrophy, region-specific preOL vulnerability, hypomyelination and persistent suppressed brain function.ConclusionsOur data provided evidence that global HI in preterm ovine fetuses resulted in profound cerebral inflammation and mobilization of the peripheral innate immune system. These inflammatory responses were paralleled by marked injury and functional loss of the preterm brain. Further understanding of the interplay between preterm brain inflammation and activation of the peripheral immune system following global HI will contribute to the development of future therapeutic interventions in preterm HIE.

Neurological Abnormalities in Full-Term Asphyxiated Newborns and Salivary S100B Testing: The “Cooperative Multitask against Brain Injury of Neonates” (CoMBINe) International Study

Background Perinatal asphyxia (PA) is a leading cause of mortality and morbidity in newborns: its prognosis depends both on the severity of the asphyxia and on the immediate resuscitation to restore oxygen supply and blood circulation. Therefore, we investigated whether measurement of S100B, a consolidated marker of brain injury, in salivary fluid of PA newborns may constitute a useful tool for the early detection of asphyxia-related brain injury. Methods We conducted a cross-sectional study in 292 full-term newborns admitted to our NICUs, of whom 48 suffered PA and 244 healthy controls admitted at our NICUs. Saliva S100B levels measurement longitudinally after birth; routine laboratory variables, neurological patterns, cerebral ultrasound and, magnetic resonance imaging were performed. The primary end-point was the presence of neurological abnormalities at 12-months after birth. Results S100B salivary levels were significantly (P<0.001) higher in newborns with PA than in normal infants. When asphyxiated infants were subdivided according to a good (Group A; n = 15) or poor (Group B; n = 33) neurological outcome at 12-months, S100B was significantly higher at all monitoring time-points in Group B than in Group A or controls (P<0.001, for all). A cut-off >3.25 MoM S100B achieved a sensitivity of 100% (CI5-95%: 89.3%-100%) and a specificity of 100% (CI5-95%: 98.6%-100%) as a single marker for predicting the occurrence of abnormal neurological outcome (area under the ROC curve: 1.000; CI5-95%: 0.987-1.0). Conclusions S100B protein measurement in saliva, soon after birth, is a useful tool to identify which asphyxiated infants are at risk of neurological sequelae.

EFFECT OF ADDITION OF BOTULINUM TOXIN-A TO STANDARDIZED THERAPY FOR DYNAMIC MANUAL SKILLS MEASURED WITH KINEMATIC AIMING TASKS IN CHILDREN WITH SPASTIC HEMIPLEGIA

OBJECTIVE To measure the effect of intensive therapy and the lasting effect of a standardized functional training programme with vs. without the addition of chemodernervation of the muscles of the forearm and hand. PATIENTS AND METHODS Twenty children with spastic hemiplegia, aged 4-16 years, were matched for baseline characteristics and randomized to standardized task-oriented therapy for 6 months with or without botulinum toxin injections. Dynamic kinematic outcome measures were: speed, accuracy, end-point spread and performance. Measurements of active and passive range of motion, stretch-restricted angle of the elbow and wrist, Ashworth scores and Melbourne Assessment of Unilateral Upper Limb Function were made. All measures were performed at baseline, 2 weeks after injection of botulinum toxin and after 6 months (at the end of therapy), and 3 months after end of the therapy. RESULTS Clinical measures showed improvement in both groups. However, no significant differences emerged between groups on functional measures. Directly after the botulinum toxin injection all kinematic outcome measures showed a decrease, but baseline values were re-established during the therapy period. After botulinum toxin injections a temporarily significant greater increase in speed and performance was found. These results illustrate the need for further quantitative research into the effects of botulinum toxin.

S100B urine concentrations in late preterm infants are gestational age and gender dependent

BACKGROUND Late preterm deliveries (LP, between 34 and 36wks), have considerably increased in the last decades. About 20-25% of LP infants who require intensive care and morbidity on public health are of great magnitude. Therefore, we aimed at offering a reference curve in LP period of a well-established neurotrophic and brain damage marker namely S100B protein. METHODS We collected, between December 2009 and March 2012, urine samples, at first void (within 6-hours from birth) for S100B assessment, in 277 healthy LP infants consecutively admitted to our units. Standard clinical and laboratory monitoring parameters were also recorded. S100B was measured by using a commercially available immunoluminometric assay. RESULTS S100B pattern in LP infants was characterized by a slight decrease in proteins concentration from 34 to 35wks. From 35wks onwards S100B started to increase reaching a significant difference (P=0.008) at 36wks. When corrected for gender, significantly higher (P<0.01, for all) S100B concentrations in female were observed from 34 to 36wks. Polynomial type-1 regression analysis showed a significant correlation (R=-0.05; P<0.001) between gestational age and S100B in LP infants considering either the whole study population or when corrected for gender. CONCLUSIONS S100B in LP infants is gestational age and gender dependent. The present reference curve, for S100B in LP period, offers additional support to proteins neurotrophic role and suggests that gestational age and gender have to be taken into due account, whenever S100B is measured, in order to avoid bias factors.

S100B Protein Maternal and Fetal bloodstreams gradient in Healthy and Small for Gestational Age Pregnancies

BACKGROUND Brain S100B assessment in maternal blood has been proposed as a useful tool for early perinatal brain damage detection. Among potential confounding factors the possibility of a protein gradient between maternal and fetal bloodstreams under pathophysiological conditions is consistent. The present study investigates in healthy and small gestational age fetuses (SGA) whether S100B concentrations differ among fetal and maternal bloodstreams. METHODS We conducted a case-control study in 160 pregnancies (SGA: n=80; healthy: n=80), in which standard monitoring parameters were recorded. S100B was assessed in arterial cord and in maternal blood samples at birth. Eighty non pregnant women (NP), matched for age at sampling, served as controls (1 SGA vs. 1 healthy vs. 1 NP). RESULTS Fetal S100B in SGA and healthy groups was significantly higher (P<0.01) than that detected in the maternal district and in NP women groups, respectively. No differences in proteins gradient between fetal and maternal bloodstreams (P>0.05) were observed between groups. No differences (P>0.05) in fetal S100B have been found between the studied groups. Maternal S100B of SGA and healthy groups was significantly higher (P<0.01) than that detected in NP women. No differences in maternal S100B concentrations (P>0.05) were observed between SGA and control groups. CONCLUSION The present study shows that S100B is pregnancy-dependent with the presence of a proteins gradient between fetal and maternal bloodstreams. The present data suggests that non-invasive fetal brain monitoring is becoming possible in opening a new cue on further investigations on S100B fetal/maternal gradient changes under pathological conditions.

Clinical observational gait analysis to evaluate improvement of balance during gait with vibrotactile biofeedback

BACKGROUND AND PURPOSE This study explores the effect of vibrotactile biofeedback on gait in 20 patients with bilateral vestibular areflexia using observational gait analysis to score individual balance. METHODS A tilt sensor mounted on the head or trunk is used to detect head or body tilt and activates, via a microprocessor, 12 equally distributed vibrators placed around the waist. Two positions of the tilt sensor were evaluated besides no biofeedback in three different gait velocity tasks (slow/fast tandem gait, normal gait on foam) resulting in nine different randomized conditions. Biofeedback activated versus inactivated was compared. Twenty patients (10 males, 10 females, age 39-77 years) with a bilateral vestibular areflexia or severe bilateral vestibular hyporeflexia, severe balance problems and frequent falls participated in this study. RESULTS Significant improvements in balance during gait were shown in our patients using biofeedback and sensor on the trunk. Only two patients showed a significant individual gait improvement with the biofeedback system, but in the majority of our patients, it increased confidence and a feeling of balance. CONCLUSION This study indicates the feasibility of vibrotactile biofeedback for vestibular rehabilitation and to improve balance during gait.

Elevated Activin A urine levels are predictors of intraventricular haemorrhage in preterm newborns

Intraventricular haemorrhage (IVH) is the most common variety of cerebral haemorrhage and cause of neurological disabilities in preterm newborns. We evaluated the usefulness of urine Activin A concentrations for the early detection of perinatal IVH.

Adrenomedullin alterations related to cardiopulmonary bypass in infants with low cardiac output syndrome

Background: Low cardiac output syndrome (LCOS) remains a major perioperative complications in infants subjected to open-heart surgery with cardiopulmonary bypass (CPB). The present study investigated whether perioperative blood assessment of a potent vasoactive peptide namely adrenomedullin (AM) can predict the risk of LCOS. Methods: We measured AM levels in 48 patients (LCOS: n = 9; controls: n = 39) undergone to open-heart surgery with CPB at five predetermined time points before, during and after the surgery. Clinical, laboratory and perioperative data were analyzed by a multiple logistic regression model. Results: AM significantly decreased (p < 0.01) during and after the surgical procedure exhibiting a dip at the end of the CPB. Multivariable analysis demonstrated significant correlations among LCOS, AM measured at the end of CPB (p < 0.001), and cooling duration (p < 0.05). AM at 27 pg/L cutoff achieved a sensitivity of 100% and a specificity of 64.1%, while cooling at 11-min cutoff combined a sensitivity of 55.6% and a specificity of 92.3% for LCOS prediction. Conclusions: This study suggests that AM can constitute, alone or combined with standard parameters, a promising predictor of LCOS in infants subjected to open-heart surgery with CPB.

Biochemical Markers for Brain Injury Monitoring in Children with or without Congenital Heart Diseases

Perinatal asphyxia (PA) still constitutes a common complication involving a large number of infants with or without congenital heart diseases (CHD). PA affects 0.2-0.6% of full-term neonates, 20% of which suffer mortal hypoxic-ischemic encephalopathy, and among survivors 25% exhibit permanent consequences at neuropsychological level. Each year, about one third of 1000 live births underwent to surgical intervention in early infancy and/or are at risk for ominous outcome. Advances in brain monitoring, in anesthetic and cardiothoracic surgical techniques, including selective or total body cooling, cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest, have essentially reduced mortality expanding the possibility to address functional neurologic and cardiac outcomes in long-term survivors. However, open-heart surgery constitutes a time-frame of planned ischemia-reperfusion injury, which is a price to pay in the treatment or palliation of CHD. Infants who underwent heart surgery and non-CHD infants complicated by PA share similarities in their neurodevelopmental profile and a common form of brain damage due to hypoxic-ischemic injury. The purpose of the present review was to evaluate different mechanisms implicated in brain injury following CPB and PA and how it is possible to monitor such injury by means of available biomarkers (S100B protein, Activin A, Adrenomedullin).

Predictors of ominous outcome in infants who undergo cardiac surgery and cardiopulmonary by-pass: S100B protein

S100B protein has been recently proposed as a consolidated marker of brain damage and death in adult, children and newborn patients. The present study evaluates whether the longitudinal measurement of S100B at different perioperative time-points may be a useful tool to identify the occurrence of perioperative early death in congenital heart disease (CHD) newborns. We conducted a case-control study in 88 CHD infants, without pre-existing neurological disorders or other co-morbidities, of whom 22 were complicated by perioperative death in the first week from surgery. Control group was composed by 66 uncomplicated CHD infants matched for age at surgical procedure. Blood samples were drawn at five predetermined timepoints before during and after surgery. In all CHD children, S100B levels showed a pattern characterized by a significant increase in proteins concentration from hospital admission up to 24-h after procedure reaching their maximum peak (P<0.01) during cardiopulmonary by-pass and at the end of the surgical procedure. Moreover, S100B concentrations in CHD death group were significantly higher (P<0.01) than controls at all monitoring time-points. The ROC curve analysis showed that S100B measured before surgical procedure was the best predictor of perioperative death, among a series of clinical and laboratory parameters, reaching at a cut-off of 0.1 µg/L a sensitivity of 100% and a specificity of 63.7%. The present data suggest that in CHD infants biochemical monitoring in the perioperative period is becoming possible and S100B can be included among a series of parameters for adverse outcome prediction.