Serum biomarkers to evaluate the integrity of the neurovascular unit

Prediction of outcome of hypoxic-ischemic encephalopathy in newborns undergoing therapeutic hypothermia using heart rate variability

OBJECTIVE

To assess the use of continuous heart rate variability (HRV) as a predictor of brain injury severity in newborns with moderate to severe HIE that undergo therapeutic hypothermia.

STUDY DESIGN

Two cohorts of newborns (n1 = 55, n2 = 41) with moderate to severe hypoxic-ischemic encephalopathy previously treated with therapeutic hypothermia. HRV was characterized by root mean square in the short time scales (RMSS) during therapeutic hypothermia and through completion of rewarming. A logistic regression and Naïve Bayes models were developed to predict the MRI outcome of the infants using RMSS. The encephalopathy grade and gender were used as control variables.

RESULTS

For both cohorts, the predicted outcomes were compared with the observed outcomes. Our algorithms were able to predict the outcomes with an area under the receiver operating characteristic curve of about 0.8.

CONCLUSIONS

HRV assessed by RMSS can predict severity of brain injury in newborns with HIE.

Plasma neuron specific enolase (NSE), tumour necrosis factor-alpha (TNF-α) and soluble IL-2 receptor alpha (sIL-2Rα) levels in children with developmental delay (DD): Use of combined ROC curves to increase their diagnostic value

BACKGROUND

Developmental delay (DD) occurs when children fail to reach developmental milestones in comparison to peers of the same age range. However, there are no valuable biomarkers for the early diagnosis of DD. Since there is no specific marker for screening the disease, we evaluated plasma NSE, TNF-α and sIL2-Rα as potential markers for this purpose.

METHODS

In this cross-sectional randomized case-control study, a total of 174 DD patients and 49 matched elderly controls aged between 2 months and 60 months were recruited. A sensitive enzyme-linked immunosorbent assay and an immunoradiometric assay were used to evaluate the levels of plasma IL-1, IL-6, IL-8, IL-10, sIL2-Rα, TNF-α, and NSE. Statistical analyses using t test, χ2, ANOVA, ROC curves and binary logistic regression models were performed.

RESULTS

In comparison to the control group, the DD group had greater levels of NSE, TNF-α, and sIL2-Rα(p < 0.05). In the binary logistic regression analysis of DD, NSE had an odds ratio (OR) of 1.783 (95 % CI 1.297 to 2.451, p = 0.000), indicating that NSE was an independent risk factor for DD. The plasma TNF-α level was positively correlated with plasma NSE and sIL2-Rα levels in the DD group (r = 0.366 and 0.433, respectively), and the DQ score and plasma sIL2-Rα level in the DD group were positively correlated. The ROC curve revealed that the respective areas under the NSE, TNF-α, and sIL2-Rα ROC curves were 0.9797, 0.9365, and 0.8533, respectively. Moreover, a significant increase in AUC was observed using combined ROC curve analysis.

CONCLUSIONS

Children with DD have significantly altered plasma concentrations of sIL2-Rα, NSE, and TNF-α. NSE, TNF-α and sIL2-Rα can be used as DD blood biomarkers. This information may be helpful in early diagnosis and intervention.

Evaluation of neurovascular coupling during neuroprotective therapies: A single site HEAL ancillary study

BACKGROUND

There is a critical need for development of physiological biomarkers in infants with birth asphyxia to identify the physiologic response to therapies in real time. This is an ancillary single site study of the High-Dose Erythropoietin for Asphyxia and Encephalopathy (Wu et al., 2022 [1]) to measure neurovascular coupling (NVC) non-invasively during an ongoing blinded randomized trial.

METHODS

Neonates who randomized in the HEAL enrolled at a single-center Level III Neonatal Intensive Care Unit were recruited between 2017 and 2019. Neurodevelopmental impairment was blinded and defined as any of the following: cognitive score <90 on Bayley Scales of Infant Toddler Development, third edition (BSID-III), Gross Motor Function Classification Score (GMFCS) ≥1.

RESULTS

All twenty-seven neonates enrolled in HEAL were recruited and 3 died before complete recording. The rank-based analysis of covariance models demonstrated lack of difference in NVC between the two groups (Epo versus Placebo) that was consistent with the observed lack of effect on neurodevelopmental outcomes.

CONCLUSION

We demonstrate no difference in neurovascular coupling after Epo administration. These findings are consistent with overall negative trial results. Physiological biomarkers can help elucidate mechanisms of neuroprotective therapies in real time in future trials.

Neuroprognostication in the Post Cardiac Arrest Patient: A Canadian Cardiovascular Society Position Statement

Cardiac arrest (CA) is associated with a low rate of survival with favourable neurologic recovery. The most common mechanism of death after successful resuscitation from CA is withdrawal of life-sustaining measures on the basis of perceived poor neurologic prognosis due to underlying hypoxic-ischemic brain injury. Neuroprognostication is an important component of the care pathway for CA patients admitted to hospital but is complex, challenging, and often guided by limited evidence. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to evaluate the evidence underlying factors or diagnostic modalities available to determine prognosis, recommendations were generated in the following domains: (1) circumstances immediately after CA; (2) focused neurologic exam; (3) myoclonus and seizures; (4) serum biomarkers; (5) neuroimaging; (6) neurophysiologic testing; and (7) multimodal neuroprognostication. This position statement aims to serve as a practical guide to enhance in-hospital care of CA patients and emphasizes the adoption of a systematic, multimodal approach to neuroprognostication. It also highlights evidence gaps.

Hiponatremili hastalarda serum nöron spesifik enolaz düzeyleri ile beyin hasarı arasındaki ilişki

Amaç: Bu çalışmada hiponatremili hastalarda serum nöron spesifik enolazın santral sinir sistemi hasarını öngörmesi ve klinik gidiş üzerindeki etkilerini araştırmayı amaçladık. Gereç ve Yöntem: Bu prospektif çalışmada, serum sodyum seviyeleri 135 mEq/L'nin altında olan 75 yetişkin hasta değerlendirildi. Hastalar serum nöron spesifik enolaz düzeylerine göre gruplandırıldı (grup 1 ≤ 17.0 ng/mL ve grup 2 > 17.0 ng/mL). Gruplar demografik ve laboratuvar verilerine göre karşılaştırıldı. Bulgular: Grup 2 hastalarında hipertansiyon, kalp yetmezliği ve bilinç kaybı insidansı anlamlı olarak daha yüksekti. Yüksek nöron spesifik enolaz seviyeleri, daha düşük serum sodyum seviyeleri ile ilişkiliydi. Ortalama sodyum seviyeleri grup 1 ve 2'de sırasıyla 129.5 ± 4.3 mEq/L ve 126 ± 4.5 mEq/L idi. Grup 2'deki hastalardan (n = 45), bilinç kaybı olan (düşük Glasgow Koma Skalası skorları) (GKS

AQP4 knockout promotes neurite outgrowth via upregulating GAP43 expression in infant rats with hypoxic-ischemic brain injury

Neonatal hypoxic-ischemic encephalopathy (NHIE) induces severe cerebral damage and neurological dysfunction, with seldom effective therapy. Aquaporin-4 (AQP4) is involved in aggravating brain damage induced by NHIE. This study aimed to investigate the role of AQP4 underlying the pathogenesis of NHIE. Neonatal Sprague-Dawley rats were used to establish neonatal hypoxic-ischemic (HI) models, and the expression of AQP4 in the cortex, hippocampus, and lung tissues was detected by real-time quantitative polymerase chain reaction as well as Western blot. Primary cortical neurons were cultured for the oxygen-glucose deprivation (OGD) model, and siRNA was used to silence the expression of AQP4. Immunostaining of Tuj1 was performed to observe the axonal growth. CRISPER/Cas9 technology was used to knock out AQP4. The results demonstrated that AQP4 was upregulated in the cortex, hippocampus, and lung tissues in neonatal rats with HI and OGD neurons. Besides, silencing AQP4 promoted axonal growth of OGD neurons, and AQP4 knockout notably improved long-term neurobehavioral impairment. Furthermore, GAP43 was found closely correlated with AQP4 via GeneMANIA prediction. Significant downregulation of GAP43 was induced in OGD neurons, while AQP4 knockout markedly upregulated its expression in rats. This indicated that the depletion of AQP4 may enhance axonal regeneration and promote the long-term neurobehavioral recovery associated with the upregulation of GAP43 expression.

Downregulating EVA1C exerts the potential to promote neuron growth after neonatal hypoxic-ischemic encephalopathy injury associated with alternative splicing

Neonatal hypoxic-ischemic encephalopathy (NHIE) is one of the major diseases in newborns during the perinatal stage, which globally is the main reason for children's morbidity and mortality. However, the mechanism of NHIE still remains poorly clear. In this study, the 7-day-old rats were subjected to hypoxic-ischemia (HI), then brain damage was detected. Afterward, the expression of eva-1 homolog C (EVA1C) was measured in vitro by establishing the oxygen-glucose deprivation (OGD) model in SHSY5Y cells and human fetal neurons. Subsequently, the potential function and mechanism of EVA1C were explored by silencing EVA1C and alternative splicing prediction. As a result, obvious neurobehavioral impairment and brain infarction were detected through Zea-Longa score and TTC staining; meanwhile, neuron injury was tested by HE and Nissl staining post HI. Moreover, it was found that the expression of EVA1C was notably upregulated in SHSY5Y cells and human fetal neurons after OGD. In addition, cell survival and growth were increased after silencing EVA1C, which might be associated with alternative splicing. In conclusion, EVA1C interference exhibited potential in promoting neuron survival and growth, associated with exon skipping with the alternative splicing site in 34613318:34687258, which may provide the basis for the therapeutic target and mechanism research of NHIE.

Proactive Management of Intraoperative Hypotension Reduces Biomarkers of Organ Injury and Oxidative Stress during Elective Non-Cardiac Surgery: A Pilot Randomized Controlled Trial

Background: Intraoperative hypotension is associated with increased postoperative morbidity and mortality. Methods: We randomly assigned patients undergoing major general surgery to early warning system (EWS) and hemodynamic algorithm (intervention group, n = 20) or standard care (n = 20). The primary outcome was the difference in hypotension (defined as mean arterial pressure < 65 mmHg) and as secondary outcome surrogate markers of organ injury and oxidative stress. Results: The median number of hypotensive episodes was lower in the intervention group (−5.0 (95% CI: −9.0, −0.5); p < 0.001), with lower time spent in hypotension (−12.8 min (95% CI: −38.0, −2.3 min); p = 0.048), correspondent to −4.8% of total surgery time (95% CI: −12.7, 0.01%; p = 0.048).The median time-weighted average of hypotension was 0.12 mmHg (0.35) in the intervention group and 0.37 mmHg (1.11) in the control group, with a median difference of −0.25 mmHg (95% CI: −0.85, −0.01; p = 0.025). Neutrophil Gelatinase-Associated Lipocalin (NGAL) correlated with time-weighted average of hypotension (R = 0.32; p = 0.038) and S100B with number of hypotensive episodes, absolute time of hypotension, relative time of hypotension and time-weighted average of hypotension (p < 0.001 for all). The intervention group showed lower Neuronal Specific Enolase (NSE) and higher reduced glutathione when compared to the control group. Conclusions: The use of an EWS coupled with a hemodynamic algorithm resulted in reduced intraoperative hypotension, reduced NSE and oxidative stress.

Challenges in developing therapeutic strategies for mild neonatal encephalopathy

There is increasing evidence that infants with mild neonatal encephalopathy (NE) have significant risks of mortality, brain injury and adverse neurodevelopmental outcomes. In the era of therapeutic hypothermia, infants need to be diagnosed within 6 hours of birth, corresponding with the window of opportunity for treatment of moderate to severe NE, compared to the retrospective grading over 2 to 3 days, typically with imaging and formal electroencephalographic assessment in the pre-hypothermia era. This shift in diagnosis may have increased the apparent prevalence of brain damage and poor neurological outcomes seen in infants with mild NE in the era of hypothermia. Abnormal short term outcomes observed in infants with mild NE include seizures, abnormal neurologic examination at discharge, abnormal brain magnetic resonance imaging and difficulty feeding. At 2 to 3 years of age, mild NE has been associated with an increased risk of autism, language and cognitive deficits. There are no approved treatment strategies for these infants as they were not included in the initial randomized controlled trials for therapeutic hypothermia. However, there is already therapeutic creep, with many centers treating infants with mild NE despite the limited evidence for its safety and efficacy. The optimal duration of treatment and therapeutic window of opportunity for effective treatment need to be specifically established for mild NE as the evolution of injury is likely to be slower, based on preclinical data. Randomized controlled trials of therapeutic hypothermia for infants with mild NE are urgently required to establish the safety and efficacy of treatment. This review will examine the evidence for adverse outcomes after mild NE and dissect some of the challenges in developing therapeutic strategies for mild NE, before analyzing the evidence for therapeutic hypothermia and other strategies for treatment of these infants.

Brain Hypoxia Is Associated With Neuroglial Injury in Humans Post-Cardiac Arrest

Supplemental Digital Content is available in the text.

Secondary brain hypoxia portends significant mortality in ischemic brain diseases; yet, our understanding of hypoxic ischemic brain injury (HIBI) pathophysiology in humans remains rudimentary.

Early Blood Biomarkers Distinguish Inflammation from Neonatal Hypoxic-Ischemia Encephalopathy

Neonatal hypoxic-ischemic encephalopathy is the most common cause of neurological disability in infancy. Superimposed inflammation may further worsen neurological outcomes. Reliable biomarkers which are both sensitive to hypoxic-ischemia and inflammation are critically needed. We tested plasma osteopontin (OPN) and glial fibrillary astrocytic protein (GFAP) within the reported therapeutic window (90 min after hypoxic-ischemic (HI) injury) in neonatal rats with different HI severity and inflammation. Two different HI severity groups (mild-HI with 75 min hypoxia and severe-HI with 150 min hypoxia) were established. Inflammation-sensitized HI brain injury induced by lipopolysaccharide (LPS) further increased apoptotic neurons and infarct volumes. In HI alone groups, OPN was significantly decreased (p < 0.001) but GFAP was slightly increased (p < 0.05) at 90 min after HI either in mild-HI or severe-HI compared with naïve group. In LPS-sensitized HI groups, both OPN and GFAP were significantly increased either in LPS-mild-HI or LPS-severe-HI groups compared with the naïve group (all p < 0.05). Induced inflammation by LPS exaggerated neonatal HI brain injury. The plasma OPN and GFAP levels may be useful to differentiate HI alone groups from inflammation-sensitized HI groups or naïve group.

B-Type Natriuretic Peptide as a Significant Brain Biomarker for Stroke Triaging Using a Bedside Point-of-Care Monitoring Biosensor

Stroke is a widespread condition that causes 7 million deaths globally. Survivors suffer from a range of disabilities that affect their everyday life. It is a complex condition and there is a need to monitor the different signals that are associated with it. Stroke patients need to be rapidly diagnosed in the emergency department in order to allow the admission of the time-limited treatment of tissue plasminogen activator (tPA). Stroke diagnostics show the use of sophisticated technologies; however, they still contain limitations. The hidden information and technological advancements behind the utilization of biomarkers for stroke triaging are significant. Stroke biomarkers can revolutionize the way stroke patients are diagnosed, monitored, and how they recover. Different biomarkers indicate different cascades and exhibit unique expression patterns which are connected to certain pathologies in the human body. Over the past decades, B-type natriuretic peptide (BNP) and its derivative N-terminal fragment (NT-proBNP) have been increasingly investigated and highlighted as significant cardiovascular biomarkers. This work reviews the recent studies that have reported on the usefulness of BNP and NT-proBNP for stroke triaging. Their classification association is also presented, with increased mortality in stroke, correlation with cardioembolic stroke, and an indication of a second stroke recurrence. Moreover, recent scientific efforts conducted for the technological advancement of a bedside point-of-care (POC) device for BNP and NT-proBNP measurements are discussed. The conclusions presented in this review may hopefully assist in the major efforts that are currently being conducted in order to improve the care of stroke patients.

Early predictors of perinatal brain damage: the role of neurobiomarkers

The early detection of perinatal brain damage in preterm and term newborns (i.e. intraventricular hemorrhage, periventricular leukomalacia and perinatal asphyxia) still constitute an unsolved issue. To date, despite technological improvement in standard perinatal monitoring procedures, decreasing the incidence of perinatal mortality, the perinatal morbidity pattern has a flat trend. Against this background, the measurement of brain constituents could be particularly useful in the early detection of cases at risk for short-/long-term brain injury. On this scenario, the main European and US international health-care institutions promoted perinatal clinical and experimental neuroprotection research projects aimed at validating and including a panel of biomarkers in the clinical guidelines. Although this is a promising attempt, there are several limitations that do not allow biomarkers to be included in standard monitoring procedures. The main limitations are: (i) the heterogeneity of neurological complications in the perinatal period, (ii) the small cohort sizes, (iii) the lack of multicenter investigations, (iv) the different techniques for neurobiomarkers assessment, (iv) the lack of consensus for the validation of assays in biological fluids such as urine and saliva, and (v), the lack of reference curves according to measurement technique and biological fluid. In the present review we offer an up-to-date overview of the most promising developments in the use of biomarkers in the perinatal period such as calcium binding proteins (S100B protein), vasoactive agents (adrenomedullin), brain biomarkers (activin A, neuron specific enolase, glial fibrillary acidic protein, ubiquitin carboxyl-terminal hydrolase-L1) and oxidative stress markers.

Transfer of mitochondria from mesenchymal stem cells derived from induced pluripotent stem cells attenuates hypoxia-ischemia-induced mitochondrial dysfunction in PC12 cells

Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury. Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology, the mechanisms are not fully understood. To address this issue, we first co-cultured 1.5 × 10⁵ PC12 cells with mesenchymal stem cells that were derived from induced pluripotent stem cells at a ratio of 1:1, and then intervened with cobalt chloride (CoCl₂) for 24 hours. Reactive oxygen species in PC12 cells was measured by Mito-sox. Mitochondrial membrane potential (?Ψm) in PC12 cells was determined by JC-1 staining. Apoptosis of PC12 cells was detected by terminal deoxynucleotidal transferase-mediated dUTP nick end-labeling staining. Mitochondrial morphology in PC12 cells was examined by transmission electron microscopy. Transfer of mitochondria from the mesenchymal stem cells derived from induced pluripotent stem cells to damaged PC12 cells was measured by flow cytometry. Mesenchymal stem cells were induced from pluripotent stem cells by lentivirus infection containing green fluorescent protein in mitochondria. Then they were co-cultured with PC12 cells in Transwell chambers and treated with CoCl₂ for 24 hours to detect adenosine triphosphate level in PC12 cells. CoCl₂-induced PC12 cell damage was dose-dependent. Co-culture with mesenchymal stem cells significantly reduced apoptosis and restored ?Ψm in the injured PC12 cells under CoCl₂ challenge. Co-culture with mesenchymal stem cells ameliorated mitochondrial swelling, the disappearance of cristae, and chromatin margination in the injured PC12 cells. After direct co-culture, mitochondrial transfer from the mesenchymal stem cells stem cells to PC12 cells was detected via formed tunneling nanotubes between these two types of cells. The transfer efficiency was greatly enhanced in the presence of CoCl₂. More importantly, inhibition of tunneling nanotubes partially abrogated the beneficial effects of mesenchymal stem cells on CoCl₂-induced PC12 cell injury. Mesenchymal stem cells reduced CoCl₂-induced PC12 cell injury and these effects were in part due to efficacious mitochondrial transfer.

Acute normobaric hypoxia does not affect the simultaneous exercise-induced increase in circulating BDNF and GDNF in young healthy men: A feasibility study

Physical exercise has a neuromodulatory effect on the central nervous system (CNS) partially by modifying expression of neuropeptides produced and secreted by neurons and glial cells, among which the best examined are brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF). Because both neurotrophins can cross the brain-blood barrier (BBB), their blood levels indirectly reflect their production in the CNS. Moreover, both neuropeptides are involved in modulation of dopaminergic and serotoninergic system function. Because limited information is available on the effects of exercise to volition exhaustion and acute hypoxia on CNS, BDNF and GDNF formation, the aims of the present study were to verify whether 1) acute exercise to exhaustion in addition to neurons also activates glial cells and 2) additional exposure to acute normobaric moderate hypoxia affects their function. In this feasibility study we measured blood concentrations of BDNF, GDNF, and neuropeptides considered as biomarkers of brain damage (bFGF, NGF, S100B, GFAP) in seven sedentary healthy young men who performed a graded exercise test to volitional exhaustion on a cycle ergometer under normoxic (N) and hypoxic conditions: 2,000 m (H2; FiO2 = 16.6%) and 3,000 m altitude (H3; FiO2 = 14.7%). In all conditions serum concentrations of both BDNF and GDNF increased immediately after cessation of exercise (p<0.01). There was no effect of condition or interaction (condition x time of measurement) and exercise on any of the brain damage biomarkers: bFGF, NGF, S100B, GFAP. Moreover, in N (0<0.01) and H3 (p<0.05) exercise caused elevated serum 5-HT concentration. The results suggest that a graded effort to volitional exhaustion in normoxia, as well as hypoxia, simultaneously activates both neurons and astrocytes. Considering that s100B, GFAP, bFGF, and NGF (produced mainly by astrocytes) are markers of brain damage, it can be assumed that a maximum effort in both conditions is safe for the CNS.

Placental clearance/synthesis of neurobiomarkers GFAP and UCH-L1 in healthy term neonates and those with moderate-severe neonatal encephalopathy

BACKGROUND

Fetal concentrations of GFAP and UCH-L1 are elevated in umbilical arterial (UmA) blood of neonates with birth asphyxia plus neonatal encephalopathy (NE), but their source and role of placental clearance/synthesis is unknown.

METHODS

Prospective cohort study of term neonates to (a) determine UmA and venous (UmV) blood concentrations of GFAP and UCH-L1 in term uncomplicated pregnancies and their placental synthesis and/or clearance and (b) compare UmA concentrations in uncomplicated pregnancies with those complicated by fetal hypoxia-asphyxia+NE. Three term groups were studied: uncomplicated cesarean delivery without labor (Group 1, n = 15), uncomplicated vaginal delivery with labor (Group 2, n = 15), and perinatal hypoxia-asphyxia+NE (Group 3, n = 8).

RESULTS

UmA GFAP concentrations were lower in Group 1 vs. 2 (P = 0.02) and both demonstrated 100% placental clearance. In contrast, UmA and UmV UCH-L1 concentrations were not unaffected by labor. Group 3 UmA GFAP concentrations were 30- and 8-fold higher than Groups 1 and 2, respectively, P = 0.02, whereas UmA UCH-L1 concentrations were similar in all groups.

CONCLUSIONS

UmA GFAP is derived from the fetus, and circulating levels, which are modulated by placental clearance, increase during uncomplicated labor and more so in the presence of fetal hypoxia-asphyxia+NE, providing a better biomarker than UCH-L1 for hypoxia-asphyxia+NE.

Should therapeutic hypothermia be offered to babies with mild neonatal encephalopathy in the first 6 h after birth?

Infants with moderate to severe neonatal encephalopathy (NE) benefit significantly from therapeutic hypothermia, with reduced risk of death or disability. However, the need for therapeutic hypothermia for infants with milder NE remains unclear. It has been suggested that these infants should not be offered therapeutic hypothermia as they may not be at risk for adverse neurodevelopmental outcome and that the balance of risk against potential benefit is unknown. Several key questions need to be answered including first, whether one can define NE in the first 6 h after birth so as to accurately distinguish infants with brain injury who may be at risk for adverse neurodevelopmental consequences. Second, will treatment of infants with mild NE with therapeutic hypothermia improve or even worsen neurological outcomes? Although alternate treatment protocols for mild NE may be feasible, the use of the current approach combined with rigorous avoidance of hyperthermia and initiation of hypothermia as early as possible after birth may promote optimal outcomes. Animal experimental data support the potential for greater benefit for mild HIE compared with moderate to severe HIE. This review will summarize current knowledge of mild NE and the challenges to a trial in this population.

Effects of Kudiezi Injection on Serum Inflammatory Biomarkers in Patients with Acute Cerebral Infarction

BACKGROUND

Kudiezi injection is a traditional Chinese medicine for acute cerebral infarction, but the exact mechanisms are poorly understood.

OBJECTIVE

To investigate the mechanisms of Kudiezi injection on the inflammatory response in the treatment of acute cerebral infarction.

METHODS

This was a prospective study of patients with acute cerebral infarction within 48 h of onset and treated between July 2012 and July 2016 at three hospitals in China. The patients were randomized to routine treatments (control group) versus routine treatments and Kudiezi injection (Kudiezi group). The National Institutes of Health Stroke Score was assessed on days 1, 3, 5, 7, and 14. The patients were tested for serum levels of pro- and anti-inflammatory cytokines (S100 calcium-binding protein B, neuron-specific enolase, interleukin-6, interleukin-10, interleukin-18, and matrix metaloproteinase-9; by enzyme-linked immunosorbent assay) immediately after admission and on days 3, 5, and 14.

RESULTS

Stroke scores were improved in both groups from days 1 to 14. On days 5 and 7, stroke scores in the Kudiezi group were lower than in the control group (P < 0.05). Compared with controls, the Kudiezi group had lower serum S100 calcium-binding protein B on day 14; higher interleukin-6 and interleukin-10 on day 3; lower interleukin-6 and interleukin-18 on day 5; and lower interleukin-18 and matrix metaloproteinase-9 on day 14.

CONCLUSION

Kudiezi injection could lead to early reduction of interleukin-6, interleukin-18, matrix metaloproteinase-9, neuron-specific enolase, and S100 calcium-binding protein B levels and increases of interleukin-10 levels in patients with acute ischemic stroke. This trial is registered with ClinicalTrials.gov NCT01636154.

A review of the conundrum of mild hypoxic-ischemic encephalopathy: Current challenges and moving forward

A review of the conundrum called mild hypoxic-ischemic encephalopathy (HIE) is provided. During the past decades, the definition of HIE has evolved to accommodate the short window of time required for the initiation of therapeutic hypothermia. Also, neurological evaluations have changed with the use of simpler staging systems that can be applied within the first 6 h of life. In this review, we discuss the challenges in the identification of newborns with "mild HIE" within 6 h after birth, the limitations in the existing early biomarkers of brain injury, and the current knowledge gaps in the long term neurodevelopmental outcomes of infants diagnosed with mild HIE. Progress in the understanding of mild HIE and its sequelae continues to be hindered by the lack of a standardized definition for mild HIE that will reliably identify at-risk infants who may benefit from neuroprotective strategies.

Point-of-Care-Testing in Acute Stroke Management: An Unmet Need Ripe for Technological Harvest

Stroke, the second highest leading cause of death, is caused by an abrupt interruption of blood to the brain. Supply of blood needs to be promptly restored to salvage brain tissues from irreversible neuronal death. Existing assessment of stroke patients is based largely on detailed clinical evaluation that is complemented by neuroimaging methods. However, emerging data point to the potential use of blood-derived biomarkers in aiding clinical decision-making especially in the diagnosis of ischemic stroke, triaging patients for acute reperfusion therapies, and in informing stroke mechanisms and prognosis. The demand for newer techniques to deliver individualized information on-site for incorporation into a time-sensitive work-flow has become greater. In this review, we examine the roles of a portable and easy to use point-of-care-test (POCT) in shortening the time-to-treatment, classifying stroke subtypes and improving patient's outcome. We first examine the conventional stroke management workflow, then highlight situations where a bedside biomarker assessment might aid clinical decision-making. A novel stroke POCT approach is presented, which combines the use of quantitative and multiplex POCT platforms for the detection of specific stroke biomarkers, as well as data-mining tools to drive analytical processes. Further work is needed in the development of POCTs to fulfill an unmet need in acute stroke management.

Brain injury with systemic inflammation in newborns with congenital heart disease undergoing heart surgery

The potential role of systemic inflammation on brain injury in newborns with congenital heart disease (CHD) was assessed by measuring levels of central nervous system (CNS)-derived proteins in serum prior to and following cardiac surgery. A total of 23 newborns (gestational age, 39±1 weeks) with a diagnosis of CHD that required cardiac surgery with cardiopulmonary bypass (CPB) were enrolled in the current study. Serum samples were collected immediately prior to surgery and 2, 24 and 48 h following CPB, and serum levels of phosphorylated neurofilament-heavy subunit (pNF-H), neuron-specific enolase (NSE) and S100B were analyzed. Systemic inflammation was assessed by measuring serum concentrations of complement C5a and complement sC5b9, and the following cytokines: Interleukin (IL)-1β, IL-6, IL-8, IL-10, IL12p70, interferon γ and tumor necrosis factor (TNF)-α. Analysis of cord blood from normal term deliveries (n=26) provided surrogate normative values for newborns. pNF-H and S100B were 2.4- to 2.8-fold higher (P<0.0001) in patient sera than in cord blood prior to surgery and remained elevated following CPB. Pre-surgical serum pNF-H and S100B levels directly correlated with interleukin (IL)-12p70 (ρ=0.442, P<0.05). pNF-H was inversely correlated with arterial pO₂ prior to surgery (ρ=−0.493, P=0.01) and directly correlated with arterial pCO₂ post-CPB (ρ=0.426, P<0.05), suggesting that tissue hypoxia and inflammation contribute to blood brain barrier (BBB) dysfunction and neuronal injury. Serum IL12p70, IL-6, IL-8, IL-10 and TNF-α levels were significantly higher in patients than in normal cord blood and levels of these cytokines increased following CPB (P<0.001). Activation of complement was observed in all patients prior to surgery, and serum C5a and sC5b9 remained elevated up to 48 h post-surgery. Furthermore, they were correlated (P<0.05) with low arterial pO₂, high pCO₂ and elevated arterial pressure in the postoperative period. Length of mechanical ventilation was associated directly with post-surgery serum IL-12p70 and IL-8 concentrations (P<0.05). Elevated serum concentrations of pNF-H and S100B in neonates with CHD suggest BBB dysfunction and CNS injury, with concurrent hypoxemia and an activated inflammatory response potentiating this effect.

Electrochemical impedimetric detection of stroke biomarker NT-proBNP using disposable screen-printed gold electrodes

Stroke is the second top leading cause of death globally. It is caused by an abrupt interruption of blood flow to the brain. In that course, brain natriuretic peptide (BNP) and its derivative N-terminal pro b-type natriuretic peptide (NT-proBNP), neurohormones produced mainly by the heart ventricles in response to excessive stretching of cardiomyocytes (heart muscle cells), are proven to be good biomarkers for heart failure diagnosis. Moreover, there is growing clinical interest of the use of NT-proBNP for stroke diagnosis and prognosis because it is significantly associated with cardioembolic stroke and secondary stroke reoccurrence, with sensitivity >90% and specificity >80%. However, in diagnostic settings, there is still a need to address the encountered analytical problems, particularly assay specificity and set up. In this study, a novel approach for NT-proBNP detection is demonstrated using an electrochemical immunoassay method. A label-free impedimetry immunosensor for stroke biomarker was developed using modified disposable screen-printed gold electrodes (SPGE) hosting specific anti-NT-proBNP capture antibody. The performance of our immunosensor was studied in the presence of NT-proBNP in both buffered and mock (porcine) plasma samples. A linear relation between the relative total resistance (ΔRtot) responses and the NT-proBNP concentrations in buffer was observed in a range from 0.1 to 5 ng mL-1 with a correlation coefficient (R2) of 0.94656. Overall, the biosensor has demonstrated the capability to quantitate NT-proBNP and differentiate such concentrations in a low concentration range, especially among 0, 0.1, 0.5, 1, and 3 ng mL-1 in plasma samples within 25 min. This range is valuable not only for classifying cardioembolic stroke (higher or equal to 0.5 ng mL-1), but also predicting the risk of secondary stroke reoccurrence (higher than 0.255 ng mL-1). Our biosensor has the potential to be used as an easy-to-use point-of-care test that is both accurate and affordable.

New Wavelet Neurovascular Bundle for Bedside Evaluation of Cerebral Autoregulation and Neurovascular Coupling in Newborns with Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy (NE) resulting from birth asphyxia constitutes a major global public health burden for millions of infants every year, and despite therapeutic hypothermia, half of these neonates have poor neurological outcomes. As new neuroprotective interventions are being studied in clinical trials, there is a critical need to establish physiological surrogate markers of therapeutic efficacy, to guide patient selection and/or to modify the therapeutic intervention. The challenge in the field of neonatal brain injury has been the difficulty of clinically discerning NE severity within the short therapeutic window after birth or of analyzing the dynamic aspects of the cerebral circulation in sick NE newborns. To address this roadblock, we have recently developed a new "wavelet neurovascular bundle" analytical system that can measure cerebral autoregulation (CA) and neurovascular coupling (NVC) at multiple time scales under dynamic, nonstationary clinical conditions. This wavelet analysis may allow noninvasive quantification at the bedside of (1) CA (combining metrics of blood pressure and cerebral near-infrared spectroscopy, NIRS) and (2) NVC (combining metrics obtained from NIRS and EEG) in newborns with encephalopathy without mathematical assumptions of linear and stationary systems. In this concept paper, we present case examples of NE using the proposed physiological wavelet metrics of CA and NVC. The new approach, once validated in large NE studies, has the potential to optimize the selection of candidates for therapeutic decision-making, and the prediction of neurocognitive outcomes.

Pathophysiology of Perinatal Hypoxic-Ischemic Encephalopathy – Biomarkers, Animal Models and Treatment Perspectives

Hypoxic-ischemic encephalopathy (HIE) is one of the leading pediatric neurological conditions causing long-term disabilities and socio-economical burdens. Nearly 20-50 % of asphyxiated newborns with HIE die within the newborn period and another third will develop severe health consequences and permanent handicaps. HIE is the result of severe systemic oxygen deprivation and reduced cerebral blood flow, commonly occurring in full-term infants. Hypoxic-ischemic changes trigger several molecular and cellular processes leading to cell death and inflammation. Generated reactive oxygen species attack surrounding cellular components resulting in functional deficits and mitochondrial dysfunction. The aim of the present paper is to review present knowledge about the pathophysiology of perinatal hypoxic-ischemic encephalopathy, especially with respect to novel treatment strategies and biomarkers that might enhance early detection of this disorder and thus improve the general outcome of patients.

Lipid peroxides in the serum of asphyxiated neonates

OBJECTIVE

Lipid peroxides (LPOs) are released when free radicals react with unsaturated fatty acids in cell membranes during hypoxic ischemic insult in neonates. We aimed to assess LPO concentrations in the serum of asphyxiated and non-asphyxiated neonates and examine their correlation with the severity of asphyxia.

STUDY DESIGN

This prospective cross-sectional study was conducted on a group of asphyxiated neonates and controls. Serum LPO concentrations was measured by enzyme-linked immunosorbent assay at 4-6 h of life in all subjects. Encephalopathy was classified according to Sarnat's stages into mild, moderate and severe at 12-24 h of life. LPO was compared between groups and was correlated with severity of encephalopathy and mortality.

RESULTS

A total of 90 infants were enrolled; of them 45 had asphyxia. Serum LPO (nmol ml(-1)) was significantly greater in the asphyxia group (6.9±3.01 vs 1.78±1.09, P<0.001). It correlated positively with severity of encephalopathy (P<0.001) and negatively with Apgar score at 5 min (r=-0.532, P<0.001) and with initial blood gases pH (r=-0.664, P<0.001). LPO measured greater concentrations in infants who died compared with asphyxiated survivors (11.64±1.31 vs 6.18±2.48, P=0.0004).

CONCLUSION

LPO was increased and correlated with severity of asphyxia as well as with mortality. Further studies are warranted to examine whether it is only a marker for outcome or a contributor in the pathogenesis of hypoxic-ischemic brain injury.

Inflammatory Biomarkers of Birth Asphyxia

Although therapies in addition to whole-body cooling are being developed to treat the neonate at risk for hypoxic-ischemic encephalopathy, we have no quickly measured serum inflammatory or neuronal biomarkers to acutely and accurately identify brain injury or to follow the efficacy of therapy. This review covers inflammatory serum biomarkers in the setting of birth asphyxia that can help assess the degree or severity of encephalopathy at birth and neurodevelopmental outcomes. These biomarkers still need to be independently validated in large cohorts before they are ready for clinical implementation in practice.

Birth Asphyxia and Hypoxic-Ischemic Brain Injury in the Preterm Infant

Birth asphyxia, also termed perinatal hypoxia-ischemia, is a modifiable condition as evidenced by improved outcomes of infants ≥36 weeks' gestation provided hypothermia treatment in randomized trials. Preterm animal models of asphyxia in utero demonstrate that hypothermia can provide short-term neuroprotection for the developing brain, supporting the interest in extending therapeutic hypothermia to preterm infants. This review focuses on the challenge of identifying preterm infants with perinatal asphyxia; the neuropathology of hypoxic-ischemic brain injury across extreme, moderate, and late preterm infants; and patterns of brain injury, use of therapeutic hypothermia, and approach to patient selection for neuroprotective treatments among preterm infants.

The effects of selective head cooling versus whole-body cooling on some neural and inflammatory biomarkers: a randomized controlled pilot study

Background

Therapeutic hypothermia (TH) has become standard care in newborns with moderate to severe hypoxic ischemic encephalopathy (HIE), and the 2 most commonly used methods are selective head cooling (SHC) and whole body cooling (WBC). This study aimed to determine if the effects of the 2 methods on some neural and inflammatory biomarkers differ.

Materials and methods

This prospective randomized pilot study included newborns delivered after >36 weeks of gestation. SHC or WBC was administered randomly to newborns with moderate to severe HIE that were prescribed TH. The serum interleukin (IL)-1β, IL-6, neuron-specific enolase (NSE), brain-specific creatine kinase (CK-BB), tumor necrosis factor-alpha (TNF-α), and protein S100 levels, the urine S100B level, and the urine lactate/creatinine (L/C) ratio were evaluated 6 and 72 h after birth. The Bayley Scales of Infant and Toddler Development-III was administered at month 12 for assessment of neurodevelopmental findings.

Results

The SHC group included 14 newborns, the WBC group included 10, the mild HIE group included 7, and the control group included 9. All the biomarker levels in the SHC and WBC groups at 6 and 72 h were similar, and all the changes in the biomarker levels between 6 and 72 h were similar in both groups. The serum IL-6 and protein S100 levels at 6 h in the SHC and WBC groups were significantly higher than in the control group. The urine L/C ratio at 6 h in the SHC and WBC groups was significantly higher than in the mild HIE and control groups. The IL-6 level and L/C ratio at 6 and 72 h in the patients that had died or had disability at month 12 were significantly higher than in the patients without disability at month 12.

Conclusion

The effects of SHC and WBC on the biomarkers evaluated did not differ. The urine L/C ratio might be useful for differentiating newborns with moderate and severe HIE from those with mild HIE. Furthermore, the serum IL-6 level and the L/C ratio might be useful for predicting disability and mortality in newborns with HIE.

Umbilical cord blood concentrations of ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) in neonates developing hypoxic-ischemic encephalopathy

OBJECTIVE

To compare ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) concentrations in umbilical cord blood of neonates who develop Sarnat stage II-III hypoxic-ischemic encephalopathy (HIE) to healthy controls, and to relate the concentrations to the severity of neurology and long-time outcomes.

MATERIAL AND METHODS

Cord sera of 15 neonates with HIE II-III and 31 matched controls were analyzed for UCH-L1 and GFAP. Comparisons were performed for cord artery pH, amplitude-integrated electroencephalography (aEEG), stage of HIE, and death or sequelae up to an age of 6 years. Parametric and non-parametric statistics were used with a two-sided p < 0.05 considered significant.

RESULTS

Among controls no associations between biomarker concentrations and gestational age, birthweight, length of storage of cord sera and degree of hemolysis were found. No significant differences in biomarker concentrations were found between HIE neonates and controls, and no differences were found with regard to HIE stage, cord acidemia, severity of aEEG changes, or persistent sequelae or death.

CONCLUSIONS

No differences in cord blood UCH-L1 and GFAP concentrations were found between HIE neonates and controls, and no associations were found between the biomarker concentrations and the severity of disease, or whether the condition developed into a permanent or fatal injury.