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Background: Brain injury is a serious problem in patients who survive out-ofhospital cardiac arrest (OHCA). Neuroprotective drugs could reduce hypoxic-- ischemic reperfusion injury. The aim of this study was to investigate the safety, tolerability, and pharmacokinetics (PK) of 2-iminobiotin (2-IB), a selective inhibitor of neuronal nitric oxide synthase. Methods: Single-center, open-label dose-escalation study in adult OHCA patients, investigating three 2-IB dosing schedules (targeting an AUC0-24h of 600-- 1,200 ng*h/m in cohort A, of 2,100--3,300 ng*h/mL in cohort B, and 7,200--8,400 of ng*h/mL in cohort C). Safety was investigated by monitoring vital signs until 15 min after study drug administration and adverse events up to 30 days after admission. Blood sampling for PK analysis was performed. Brain biomarkers and patient outcomes were collected 30 days after OHCA. Results: A total of 21 patients was included, eight in cohort A and B and five in cohort C. No changes in vital signs were observed, and no adverse events related to 2-IB were reported. A two-compartment PK model described data the best. Exposure in group A (dosed on bodyweight) was three times higher than targeted (median AUC0-24h 2,398 ng*h/mL). Renal function was an important covariate; therefore, in cohort B, dosing was performed on eGFR on admission. In cohort B and C, the targeted exposure was met (median AUC0-24h 2,917 and 7,323 ng*h/ mL, respectively). Conclusion: The administration of 2-IB to adults after OHCA is feasible and safe. PK can be well predicted with correction for renal function on admission. Efficacy studies with 2-IB after OHCA are needed. [ABSTRACT FROM AUTHOR]

Timely detection of severe infratentorial hemorrhage in neonates is crucial, especially in case of life-threatening brain stem compression and/or acute obstructive hydrocephalus, which need lifesaving neurosurgical intervention. Although the detection of infratentorial hemorrhage by ultrasound scanning is often considered as difficult, the use of additional acoustic windows and recognition of characteristic ultrasound features facilitate early diagnosis. In this case series, we report on newborns with severe, symptomatic infratentorial hemorrhage detected primarily by cranial ultrasound. We demonstrate the characteristic ultrasound features present in all cases and discuss how ultrasound diagnosis contributed to early diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Aim: Perinatal asphyxia is one of the most frequent causes of neonatal morbidity and mortality worldwide, and 96% of the burden of neonatal encephalopathy occurs in low-income countries. This study investigated the feasibility of providing neuroprotective treatment for neonatal encephalopathy in low-income countries.Methods: Neonates with a gestational age of at least 36 weeks, with signs of perinatal asphyxia, were included in this 2015 observational study in three hospitals in Kinshasa, capital of the Democratic Republic of Congo. Their characteristics were described, including the time to admission and Thompson score on admission.Results: We found that 42 of 134 patients (31.3%) reached the hospital within six hours of birth with a Thompson score of at least seven on admission. Another 15 patients (11.2%) had a five-minute Apgar score of up to five, without a Thompson score, and were eligible for treatment. Of the 57 (42.5%) eligible patients, 31 were discharged (54.4%), 25 died (43.9%) and one (1.8%) remained in hospital at the end of the study.Conclusion: Interventional studies are feasible and necessary, especially in countries where the burden of neonatal encephalopathy is largest. A Thompson score of 7-15 might be a useful entry criterion for neuroprotective treatment in low-income countries. [ABSTRACT FROM AUTHOR]

Pathogenic variants in the PCDH19 gene are associated with epilepsy, intellectual disability (ID) and behavioural disturbances. Only heterozygous females and mosaic males are affected, likely due to a disease mechanism named cellular interference. Until now, only four affected mosaic male patients have been described in literature. Here, we report five additional male patients, of which four are older than the oldest patient reported so far. All reported patients were selected for genetic testing because of developmental delay and/or epilepsy. Custom-targeted next generation sequencing gene panels for epilepsy genes were used. Clinical data were collected from medical records. All patients were mosaic in blood for likely pathogenic variants in the PCDH19 gene. In most, clinical features were very similar to the female phenotype, with normal development before seizure onset, which occurred between 5 and 10 months of age, clustering of seizures and sensitivity to fever. Four out of five patients had mild to severe ID and behavioural problems. We reaffirm the similarity between male and female PCDH19-related phenotypes, now also in a later phase of the disorder (ages 10-14 years). [ABSTRACT FROM AUTHOR]

Familial hemophagocytic lymphohistiocytosis (fHLH) is an autosomal recessive disorder characterized by proliferation and infi ltration of several organs by activated lymphocytes and macrophages. Without allogeneic stem cell transplantation, fHLH is fatal. We describe a previously healthy 11-month-old boy with a rapidly progressive encephalopathy. An older brother died at 8 months following a subacute encephalopathy diagnosed as meningoencephalitis. The family history led to the suspicion of a metabolic disease, but metabolic studies were unrevealing. MRI showed multiple inhomogeneous signal abnormalities in the cortex and white matter, most prominent in the cerebral hemispheres and around the dentate nucleus. Gadoliniumenhanced T 1 -weighted images showed a multitude of enhancing foci, suggestive of perivascular enhancement. Based on MRI pattern with multiple lesions, perivascular enhancement and family history, fHLH was suspected. DNA analysis showed that the patient was compound-heterozygous for the c.445 G > A (p.Gly149Ser) mutation in exon 1 and the c.757 G > A (p.Glu253Lys) mutation in exon 2 of the perforin 1 gene. The patient was treated according to the international HLH-2004 protocol (dexamethasone, etoposide, cyclosporine, intrathecal methotrexate and prednisolone) followed by allogeneic cord blood transplantation. He showed a signifi - cant neurological and radiological improvement. The reported case demonstrates that MRI pattern recognition can lead to early diagnosis of fHLH, with subsequent adequate treatment. [ABSTRACT FROM AUTHOR]

Preterm infants are at risk of developing social-emotional and behavioural difficulties. To understand the experiences of their caregivers in day-to-day life, parents (at 2 and 10 years) and teachers (at 10 years) completed a behavioural questionnaire and answered two open-ended questions addressing their concerns and the most positive aspects regarding their child and/or pupil (born <32 weeks gestation). Their answers were analyzed using thematic content analysis. Parental concerns at two years related equally to themes in the clusters Developmental Milestones, Physical Development and Development in Relation to the Self and Others. At 10 years, both parents and teachers reported mainly within the cluster Development in Relation to the Self and Others, but the underlying themes differed. While parents more often mentioned their child's emotional development, teachers were more concerned about their pupils' difficulties interacting with their peers, due to a lack of social skills. In-depth qualitative analysis of what parents and teachers experience from day-to-day improves our understanding of the social-emotional and behavioural development of children born very preterm, revealing important topics that should be addressed during follow-up., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Cacha Peeters-Scholte is founder and consultant at Neurophyxia BV. She holds several patents and stocks of Neurophyxia BV. None of this work has a relationship with the current manuscript.

Survivors of out-of-hospital cardiac arrest (OHCA) experience between 30% and 50% cognitive deficits several years post-discharge. Especially spatial memory is affected due to ischemia-induced neuronal damage in the hippocampus. Aim of this study was to investigate the potential neuroprotective effect of 2-iminobiotin (2-IB), a biotin analogue, on memory and learning in a four-vessel occlusion model of global ischemia using the Water Maze test. Sprague-Dawley rats were randomly assigned to either sham operation (n = 6), vehicle treatment (n = 20), 1.1 (n = 15), 3.3 (n = 14), 10 (n = 14), or 30 mg/kg/dose 2-IB treatment (n = 15). Treatment was subcutaneously (s.c.) administered immediately upon reperfusion, at 12h, and at 24h after reperfusion. Memory function on day 32 was significantly preserved in all doses of 2-IB rats compared to vehicle, as was the learning curve in the 1.1, 3.3 and 30 mg/kg dose group. Adult rats treated s.c. with 3 gifts of 2-IB every 12 h in a dose range of 1.1-30 mg/kg/dose directly upon reperfusion showed significant improved memory and learning after four vessel occlusion compared to vehicle-treated rats. Since 2-IB has already shown to be safe in a phase 1 clinical trial in adult human volunteers, it is a suitable candidate for translation to a human phase 2 study after OHCA., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: CPS has stocks of Neurophyxia BV and is co-inventor onthe patents. Neurophyxia BV holds several patent families: 2-iminobiotin formulations and uses thereof (WO2011149349), 2-iminobiotin for use in the treatment of brain cell injury (WO2017105237); 2-iminobiotin for use in the treatment of stroke (WO2022203504 and WO2022203505)., (Copyright: © 2023 Peeters-Scholte et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Aim: The main burden of hypoxic-ischemic encephalopathy falls in low-income countries. 2-Iminobiotin, a selective inhibitor of neuronal and inducible nitric oxide synthase, has been shown to be safe and effective in preclinical studies of birth asphyxia. Recently, safety and pharmacokinetics of 2-iminobiotin treatment on top of hypothermia has been described. Since logistics and the standard of medical care are very different in low-resource settings, the aim of this study was to investigate safety and pharmacokinetics of Two-IminoBiotin in the Democratic Republic of Congo (TIBC)., Methods: Near-term neonates, born in Kinshasa, Democratic Republic of Congo, with a Thompson score ≥ 7 were eligible for inclusion. Excluded were patients with (1) inability to insert an umbilical venous catheter for administration of the study drug; (2) major congenital or chromosomal abnormalities; (3) birth weight < 1800 g; (4) clear signs of infection; and (5) moribund patients. Neonates received six infusions of 2-iminobiotin 0.16 mg/kg started within 6 h after birth, with 4-h intervals, targeting an AUC 0-4h of 365 ng*h/mL. Safety, defined as vital signs, the need for clinical intervention after administration of study drug, occurrence of (serious) adverse events, and pharmacokinetics were assessed., Results: After parental consent, seven patients were included with a median Thompson score of 10 (range 8-16). No relevant changes in vital signs were observed over time. There was no need for clinical intervention due to administration of study drug. Three patients died, two after completing the study protocol, one was moribund at inclusion and should not have been included. Pharmacokinetic data of 2-iminobiotin were best described using a two-compartment model. Median AUC 0-4h was 664 ng*h/mL (range 414-917). No safety issues attributed to the administration of 2-iminobiotin were found., Conclusion: The present dosing regimen resulted in higher AUCs than targeted, necessitating a change in the dose regimen in future efficacy trials. No adverse effects that could be attributed to the use of 2-iminobiotin were observed. EudraCT number 2015-003063-12.

Objective: To determine classroom-evaluated school performance nine years after preterm birth, predicted by perinatal risk factors and neonatal brain abnormalities., Study Design: Children were recruited from a consecutive cohort of 113 preterm infants (<32 weeks' gestation), participating in a longitudinal prospective study, investigating brain injury and neurodevelopmental outcome. Data on perinatal risk factors, presence of brain injury at term-equivalent age, and maternal education were collected. Information on school performance included enrollment in special (primary) education, grade repetition and school results from the nationwide standardized Dutch Pupil Monitoring System regarding reading comprehension, spelling, and mathematics., Results: Information on school enrollment was available for 87 children (77%), of whom 7 (8%) were in special primary education and 19 (22%) repeated a grade. This was significantly higher compared to national rates (p ≤ .05). Results on school performance were available for 74 children (65%) and showed clearly below average scores in reading comprehension (p = .006), spelling (p = .014) and mathematics (p < .001). Univariate analysis showed that lower performance in reading comprehension was predicted by male sex and low maternal education; spelling by male sex; and mathematics by Bronchopulmonary Dysplasia, white matter injury and maternal education. In a multivariate model, male sex and maternal education were predictive for reading comprehension and white matter injury for mathematics., Conclusion: Preterm born children more often need special primary education and have higher grade repeat rates. They perform poorer on reading comprehension, spelling and mathematics. Regular follow-up remains important for preterm born children during school age., Competing Interests: Declaration of competing interest None., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Perinatal asphyxia is characterized by oxygen deprivation and lack of perfusion in the perinatal period, leading to hypoxic-ischemic encephalopathy and sequelae such as cerebral palsy, mental retardation, cerebral visual impairment, epilepsy and learning disabilities. On cellular level PA is associated with a decrease in oxygen and glucose leading to ATP depletion and a compromised mitochondrial function. Upon reoxygenation and reperfusion, the renewed availability of oxygen gives rise to not only restoration of cell function, but also to the activation of multiple detrimental biochemical pathways, leading to secondary energy failure and ultimately, cell death. The formation of reactive oxygen species, nitric oxide and peroxynitrite plays a central role in the development of subsequent neurological damage. In this review we give insight into the pathophysiology of perinatal asphyxia, discuss its clinical relevance and summarize current neuroprotective strategies related to therapeutic hypothermia, ischemic postconditioning and pharmacological interventions. The review will also focus on the possible neuroprotective actions and molecular mechanisms of the selective neuronal and inducible nitric oxide synthase inhibitor 2-iminobiotin that may represent a novel therapeutic agent for the treatment of hypoxic-ischemic encephalopathy, both in combination with therapeutic hypothermia in middle- and high-income countries, as well as stand-alone treatment in low-income countries., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Perinatal asphyxia represents one of the major causes of neonatal morbidity and mortality. Hypothermia is currently the only established treatment for hypoxic-ischemic encephalopathy (HIE), but additional pharmacological strategies are being explored to further reduce the damage after perinatal asphyxia. The aim of this study was to evaluate whether 2-iminobiotin (2-IB) superimposed on hypothermia has the potential to attenuate hypoxia-induced injury of neuronal cells. In vitro hypoxia was induced for 7 h in neuronal IMR-32 cell cultures. Afterwards, all cultures were subjected to 25 h of hypothermia (33.5°C), and incubated with vehicle or 2-IB (10, 30, 50, 100, and 300 ng/ml). Cell morphology was evaluated by brightfield microscopy. Cell damage was analyzed by LDH assays. Production of reactive oxygen species (ROS) was measured using fluorometric assays. Western blotting for PARP, Caspase-3, and the phosphorylated forms of akt and erk1/2 was conducted. To evaluate early apoptotic events and signaling, cell protein was isolated 4 h post-hypoxia and human apoptosis proteome profiler arrays were performed. Twenty-five hour after the hypoxic insult, clear morphological signs of cell damage were visible and significant LDH release as well as ROS production were observed even under hypothermic conditions. Post-hypoxic application of 2-IB (10 and 30 ng/ml) reduced the hypoxia-induced LDH release but not ROS production. Phosphorylation of erk1/2 was significantly increased after hypoxia, while phosphorylation of akt, protein expression of Caspase-3 and cleavage of PARP were only slightly increased. Addition of 2-IB did not affect any of the investigated proteins. Apoptosis proteome profiler arrays performed with cellular protein obtained 4 h after hypoxia revealed that post-hypoxic application of 2-IB resulted in a ≥ 25% down regulation of 10/35 apoptosis-related proteins: Bad, Bax, Bcl-2, cleaved Caspase-3, TRAILR1, TRAILR2, PON2, p21, p27, and phospho Rad17. In summary, addition of 2-IB during hypothermia is able to attenuate hypoxia-induced neuronal cell damage in vitro . Combination treatment of hypothermia with 2-IB could be a promising strategy to reduce hypoxia-induced neuronal cell damage and should be considered in further animal and clinical studies.

Several animal models have been used to simulate cerebral hypoxia-ischemia and suggested neuroprotective effects of the biotin analogue 2-iminobiotin (2-IB). The aims of this study were to employ a human in-vitro hypoxia model to confirm protective effects of 2-IB on neuronal cells, determine the optimal neuroprotective concentrations of 2-IB and scrutinize underlying cellular effects of 2-IB. Neuronal IMR-32 cells were exposed to hypoxia employing an enzymatic hypoxia system and were thereafter incubated with various concentrations of 2-IB (10 to 300ng/ml). Cell damage, metabolic activity and generation of reactive oxygen species were quantified using colorimetric/fluorometric lactate dehydrogenase (LDH), tetrazolium-based (MTS) and reactive oxygen species assays. Proteome profiling arrays were performed to evaluate the regulation of cell stress protein expression by hypoxia and 2-IB. Seven hours of hypoxia led to morphological changes in IMR-32 cultures, increased neuronal cell damage (P<0.001), reduction of metabolic activity (P<0.01) and enhanced reactive oxygen species production (P<0.05). Post-hypoxic application of 2-IB (30ng/ml) attenuated hypoxia-induced LDH release (P<0.05) and increased metabolic activity of IMR-32 cells (P<0.05), while reactive oxygen species production was only by trend decreased. Array-based protein expression profiling revealed that 2-IB attenuated the expression of several hypoxia-induced cell stress-associated proteins by more than 25% (pp38α, HIF2α, ADAMTS1, pHSP27, PON2, PON3 and p27). Hypoxia-induced neuronal cell damage can be simulated using the described in-vitro model. 2-IB inhibits hypoxia-mediated neurotoxicity most efficiently at 30ng/ml and the underlying mechanisms involve a downregulation of stress-associated protein expression. Our results suggest 2-IB as a potential drug for the treatment of perinatal hypoxia-ischemia., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Arterial ischaemic stroke is an important cause of morbidity in children. Timely diagnosis is necessary for acute stroke treatment but can be challenging in clinical practice. Due to a paucity of data there are no specific recommendations regarding the use of mechanical thrombectomy devices in current paediatric stroke guidelines. A 14-year-old boy presented with a severe acute left hemisphere stroke due to a proximal middle cerebral artery occlusion caused by emboli from an atrial myxoma. No clinical improvement was seen after administration of intravenous thrombolysis. Subsequent mechanical thrombectomy with a second-generation stent-based thrombectomy device resulted in successful recanalization and clinical improvement. To our knowledge, this is the first report of mechanical thrombectomy in a child with acute embolic stroke caused by atrial myxoma.

Familial hemophagocytic lymphohistiocytosis (fHLH) is an autosomal recessive disorder characterized by proliferation and infiltration of several organs by activated lymphocytes and macrophages. Without allogeneic stem cell transplantation, fHLH is fatal. We describe a previously healthy 11-month-old boy with a rapidly progressive encephalopathy. An older brother died at 8 months following a subacute encephalopathy diagnosed as meningoencephalitis. The family history led to the suspicion of a metabolic disease, but metabolic studies were unrevealing. MRI showed multiple inhomogeneous signal abnormalities in the cortex and white matter, most prominent in the cerebral hemispheres and around the dentate nucleus. Gadolinium-enhanced T1-weighted images showed a multitude of enhancing foci, suggestive of perivascular enhancement. Based on MRI pattern with multiple lesions, perivascular enhancement and family history, fHLH was suspected. DNA analysis showed that the patient was compound-heterozygous for the c.445 G>A (p.Gly149Ser) mutation in exon 1 and the c.757 G>A (p.Glu253Lys) mutation in exon 2 of the perforin 1 gene. The patient was treated according to the international HLH-2004 protocol (dexamethasone, etoposide, cyclosporine, intrathecal methotrexate and prednisolone) followed by allogeneic cord blood transplantation. He showed a significant neurological and radiological improvement. The reported case demonstrates that MRI pattern recognition can lead to early diagnosis of fHLH, with subsequent adequate treatment., (© Georg Thieme Verlag KG Stuttgart · New York.)

Excessive nitric oxide (NO) production after cerebral hypoxia-ischaemia (HI) may induce cellular injury in various ways, including reaction with superoxide to form the highly reactive peroxynitrite. We characterized the spatial and temporal formation of peroxynitrite through immunohistochemical detection of nitrosylated proteins. Nitrotyrosine immunoreactivity peaked around 3 h post-HI and was detected in areas of injury, as judged by the loss of microtubule-associated protein-2 (MAP-2) staining, in neurones, glia and endothelial cells. Nitrotyrosine staining co-localized with three other cellular markers of injury, active caspase-3, nuclear translocation of apoptosis-inducing factor (AIF) and an oligonucleotide hairpin probe detecting specific DNA strand breaks. The number of nitrotyrosine-positive cells at early time points outnumbered the cells positive for the other three markers of injury, indicating that nitrosylation preceded caspase-3 activation. Pharmacological inhibition of neuronal and inducible nitric oxide synthase (nNOS and iNOS) using 2-iminobiotin, which has been demonstrated earlier to be neuroprotective, significantly reduced nitrotyrosine formation and caspase-3 activation, but not nuclear translocation of AIF, in cortex and striatum of the ipsilatral hemisphere. In summary, nitrotyrosine is an early marker of cellular injury and inhibition of nNOS and iNOS is a promising strategy for neuroprotection after perinatal HI.

Early detection of delayed cerebral energy failure may be important in the prevention of reperfusion injury of the brain after severe perinatal hypoxia-ischaemia (HI). This study investigated whether monitoring of the redox state of cytochrome aa(3) (Cytaa(3)) with near infrared spectroscopy (NIRS) after severe perinatal asphyxia may allow us to detect early a compromised energy metabolism of the developing brain. We therefore correlated serial Cytaa(3) measurements (to estimate mitochondrial oxygenation) simultaneously with the (31)phosphorous-magnetic resonance spectroscopy ((31)P-MRS)-measured phosphocreatin/inorganic phosphate (PCr/Pi) ratio (to estimate cerebral energy reserve) in newborn piglets before and after severe hypoxia-ischaemia. The animals were treated upon reperfusion with either allopurinol, deferoxamine, or 2-iminobiotin or with a vehicle to reduce post-HI reperfusion injury of the brain. Four sham-operated piglets served as controls. Before HI, the individual Cytaa(3) values ranged between -0.02 and 0.71 micromol/L (mean value: -0.07) relative to baseline. The pattern over post-HI time of the vehicle-treated animals was remarkably different from the other groups in as far Cytaa(3) became more oxidised from 3 h after start of HI onwards (increase of Cytaa(3) as compared with baseline), whereas the other groups showed a significant reduction over time (decrease of Cytaa(3) as compared with baseline: allopurinol and deferoxamine) or hardly any change (2-iminobiotin and sham-operated piglets). Vehicle-treated piglets showed a significant reduction in PCr/Pi at 24 h after start of HI, but the cerebral energy state was preserved in 2-iminobiotin-, allopurinol- and deferoxamine-treated piglets. With severe reduction in PCr/Pi-ratio, major changes in the redox-state of Cytaa(3) also occurred: Cytaa(3) was mostly either in a reduced state (down to -6.45 micromol/L) or in an oxidised state (up to 6.84 micromol/L) at these low PCr/Pi ratios. The positive predictive value (PPV) of Cytaa(3) to predict severe reduction of the PCr/Pi ratio was 42%; the negative PPV was 87%. A similar relation was found for Cytaa(3) with histologically determined loss of neurons.

The hypothesis was tested that treatment with allopurinol, a xanthine oxidase inhibitor, or deferoxamine, a chelator of nonprotein-bound iron, preserved cerebral energy metabolism, attenuated development of edema, and improved histologic outcome in the newborn piglet at 24 h after hypoxia-ischemia. Thirty-two newborn piglets were subjected to 1 h of hypoxia-ischemia by occluding both carotid arteries and reducing the fraction of inspired oxygen; five newborn piglets served as sham-operated controls. The depth of hypoxia-ischemia was controlled by phosphorous magnetic resonance spectroscopy. Upon reperfusion and reoxygenation, piglets received vehicle (n= 12), allopurinol (30 mg/kg/d, n = 10), or deferoxamine (12.5 mg/kg/d, n = 10). The cerebral energy status was determined with phosphorous magnetic resonance spectroscopy. The presence of vasogenic edema was assessed by T2-weighted magnetic resonance imaging. Brain cell injury was assessed with caspase-3 activity, histology, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end (TUNEL)-labeling. At 24 h after hypoxia-ischemia, the phosphocreatine/inorganic phosphate ratios were significantly decreased in vehicle-treated, but not in allopurinol- or deferoxamine-treated piglets. Water T2 values were significantly increased at 24 h after hypoxia-ischemia in cerebral cortex, thalamus, and striatum of vehicle-treated piglets, but not in allopurinol- and deferoxamine-treated piglets. No differences in caspase-3 activity, histologic outcome, or TUNEL-labeling were demonstrated between the three treatment groups. We suggest that allopurinol and deferoxamine may have an additional value in the treatment of perinatal hypoxia-ischemia with other neuroprotective agents or in combination with hypothermia.

The purpose of this study was to investigate whether combined inhibition of neuronal and inducible nitric oxide synthase (NOS) by 2-iminobiotin, free radical scavenging by allopurinol, and non-protein-bound iron chelation with deferoxamine improved cerebral oxygenation, electrocortical brain activity, and brain energy status during the first 24 h after hypoxia-ischemia (HI) in the newborn piglet. Forty-three newborn piglets were subjected to 1 h of severe HI by occluding both carotid arteries and phosphorous magnetic resonance spectroscopy ((31)P-MRS)-guided hypoxia, whereas five served as sham-operated controls. Upon reperfusion, piglets received vehicle (n=12), 2-iminobiotin (n=11), allopurinol (n=10), or deferoxamine (n=10). Cerebral oxygenation was recorded with near-infrared spectrophotometry (NIRS), electrocortical brain activity was assessed with amplitude-integrated EEG (aEEG), and cerebral energy status with (31)P-MRS. The oxygenated hemoglobin (HbO(2)) and total hemoglobin (tHb) were significantly increased in vehicle-treated piglets compared with 2-iminobiotin-treated and deferoxamine-treated piglets. No change in deoxygenated Hb (HHb) was demonstrated over time. The aEEG was significantly preserved in 2-iminobiotin- and deferoxamine-treated piglets compared with vehicle-treated piglets. Allopurinol treatment was not as effective as 2-iminobiotin treatment after HI. Phosphocreatine/inorganic phosphate ratios (PCr/P(i)) were significantly decreased for vehicle-treated piglets at 24 h post-HI, whereas 2-iminobiotin, allopurinol, and deferoxamine prevented the development of secondary energy failure. We speculate that the beneficial effects, especially of 2-iminobiotin, but also of deferoxamine, are due to reduced peroxynitrite-mediated oxidation.

Background and Purpose: Perinatal hypoxia-ischemia is a major cause of neonatal morbidity and mortality. Until now no established neuroprotective intervention after perinatal hypoxia-ischemia has been available. The delay in cell death after perinatal hypoxia-ischemia creates possibilities for therapeutic intervention after the initial insult. Excessive nitric oxide and reactive oxygen species generated on hypoxia-ischemia and reperfusion play a key role in the neurotoxic cascade. The present study examines the neuroprotective properties of neuronal and inducible but not endothelial nitric oxide synthase inhibition by 2-iminobiotin in a piglet model of perinatal hypoxia-ischemia., Methods: Twenty-three newborn piglets were subjected to 60 minutes of hypoxia-ischemia, followed by 24 hours of reperfusion and reoxygenation. Five additional piglets served as sham-operated controls. On reperfusion, piglets were randomly treated with either vehicle (n=12) or 2-iminobiotin (n=11). At 24 hours after hypoxia-ischemia, the cerebral energy state, presence of vasogenic edema, amount of apparently normal neuronal cells, caspase-3 activity, amount of terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL)-positive cells, and degree of tyrosine nitration were assessed., Results: A 90% improvement in cerebral energy state, 90% reduction in vasogenic edema, and 60% to 80% reduction in apoptosis-related neuronal cell death were demonstrated in 2-iminobiotin-treated piglets at 24 hours after hypoxia- ischemia. A significant reduction in tyrosine nitration in the cerebral cortex was observed in 2-iminobiotin-treated piglets, indicating decreased formation of reactive nitrogen species., Conclusions: Simultaneous and selective inhibition of neuronal and inducible nitric oxide synthase by 2-iminobiotin is a promising strategy for neuroprotection after perinatal hypoxia-ischemia.

Perinatal asphyxia models are necessary to obtain knowledge of the pathophysiology of hypoxia-ischaemia (HI) and to test potential neuroprotective strategies. The present study was performed in newborn piglets to obtain information about simultaneous changes in cerebral oxygenation and haemodynamics and electrocortical brain activity during a 60-min period of HI and up to 2 h of reperfusion using near infrared spectrophotometry (NIRS) and the amplitude-integrated EEG (aEEG). HI was induced by occluding both carotid arteries and decreasing the fraction of inspired oxygen (FiO(2)) to 0.08-0.12 for 60 min. The mean arterial blood pressure (MABP) and heart rate increased, the oxygenated haemoglobin (O(2)Hb) decreased, and the deoxygenated haemoglobin (HHb) increased, but total haemoglobin (tHb) remained stable during the 60-min HI period. The regional oxygen saturation (rSO(2)) was significantly decreased during the whole HI period, as was the electrocortical brain activity. Upon reperfusion and reoxygenation, the MABP normalised to baseline values but the heart rate remained increased. O(2)Hb and HHb recovered to baseline values and tHb remained unchanged. As indicated by the unchanged tHb values during the HI period, it was suggested that compensatory cerebral perfusion occurred during this period, probably via the vertebrobasilar arterial system. Furthermore, in this model a clear hyperperfusion period directly upon reperfusion and reoxygenation is not present. rSO(2) showed a quick recovery to baseline values, but the aEEG-measured electrocortical brain activity remained reduced following HI. In conclusion, the rSO(2) and aEEG showed a different time profile following perinatal asphyxia. The stable tHb during HI and reperfusion in this model differs from observations in human neonates.

Selective inhibition of neuronal and inducible nitric oxide synthase (NOS) with 2-iminobiotin previously showed a reduction in brain cell injury. In the present study, we investigated the effects of 2-iminobiotin treatment on insulin-like growth factor-1 (IGF-1) expression, caspase activity and cytokine expression in a newborn piglet model of perinatal hypoxia-ischaemia. Newborn piglets were subjected to 1 h of hypoxia-ischaemia and were treated intravenously with vehicle or 2-iminobiotin. Vehicle-treated piglets showed reduced IGF-1 mRNA expression and increased caspase-3 activity and DNA fragmentation. 2-Iminobiotin treatment, administered immediately upon reperfusion, prevented these observations. No differences in caspase-8 and -9 activity and cytokine [interleukin (IL)-1alpha/beta, IL-6, tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta] mRNA expression were demonstrated between vehicle- and 2-iminobiotin-treated piglets at 24 h following hypoxia-ischaemia. IGF-1 mRNA correlated inversely with caspase-3 and transferase-mediated dUTP-biotin in situ nick end labelling score in the cortex, but positively with caspase-8. Cytokine mRNA did not correlate with IGF-1 mRNA, caspase-3 activity or DNA fragmentation. The present results indicate that the previously demonstrated neuroprotective effect of 2-iminobiotin treatment after perinatal hypoxia-ischaemia coincided with a preservation of the endogenous IGF-1 production and reduced caspase-3 activity, but not with a significant decrease in cytokine production., (Copyright 2002 S. Karger AG, Basel)