Contribution of fetal blood sampling to determining the prognosis of congenital cytomegalovirus infections: a case-cohort study in Switzerland

BACKGROUND

Cytomegalovirus is responsible for the most common congenital infection, affecting 0.5% to 1.0% of live births in Europe. Congenital cytomegalovirus infection can be diagnosed during pregnancy by viral DNA amplification in the amniotic fluid, but the prognosis of fetuses without severe brain abnormalities remains difficult to establish on the basis of prenatal imaging alone.

OBJECTIVE

To identify predictors of moderate to severe symptomatic cytomegalovirus infection among fetal blood parameters and to propose an algorithm on the basis of these parameters and on prenatal imaging that would provide the best positive and negative predictive values.

STUDY DESIGN

Fetal blood sampling at 21-28 weeks gestation was performed in fetuses with congenital cytomegalovirus infection confirmed by amniocentesis after maternal infection in the first-trimester or periconceptional period. We compared the levels of hemoglobin, thrombocytes, γ-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, β2-microglobulin, immunoglobulins G and M, and cytomegalovirus DNA viral loads in amniotic fluid and fetal blood between those with moderate to severe symptomatic infection and those with asymptomatic to mild infection (median follow-up of 36 months for live births).

RESULTS

Among 58 fetuses included, 25 (43%) had a moderate to severe symptomatic infection: 16 with severe cerebral abnormalities, 5 with multiple signs or symptoms at birth, 2 with bilateral sensorineural hearing loss, and 2 with neurodevelopmental delay. The values of thrombocytes, aspartate aminotransferase, β2 microglobulin, Immunoglobulin M, and cytomegalovirus viral loads differed significantly between fetuses with moderate to severe symptomatic infection and those with asymptomatic to mild infection. The optimal strategy to predict moderate to severe symptomatic infection was to first perform fetal brain imaging, followed by fetal blood sampling with the following cutoffs: thrombocytes <120,000/mL, viremia ≥5 log10/mL, and β2 microglobulin ≥12 mg/L). This recursive algorithm had a negative predictive value of 100% for moderately to severely symptomatic infection.

CONCLUSION

The combination of thrombocytes, β2-microglobulin, and cytomegalovirus viral load in fetal blood can be used for prognosis determination, particularly in cytomegalovirus-infected fetuses without severe brain abnormalities at the time of prenatal diagnosis. Future studies should evaluate whether these parameters remain useful in infected fetuses who have been treated with valacyclovir before fetal blood sampling.

Neuroimaging in infants with congenital cytomegalovirus infection and its correlation with outcome: emphasis on white matter abnormalities

OBJECTIVE

To evaluate the association between neuroimaging and outcome in infants with congenital cytomegalovirus (cCMV), focusing on qualitative MRI and quantitative diffusion-weighted imaging of white matter abnormalities (WMAs).

METHODS

Multicentre retrospective cohort study of 160 infants with cCMV (103 symptomatic). A four-grade neuroimaging scoring system was applied to cranial ultrasonography and MRI acquired at ≤3 months. WMAs were categorised as multifocal or diffuse. Temporal-pole WMAs (TPWMAs) consisted of swollen or cystic appearance. Apparent diffusion coefficient (ADC) values were obtained from frontal, parieto-occipital and temporal white matter regions. Available follow-up MRI at ≥6 months (N=14) was additionally reviewed. Neurodevelopmental assessment included motor function, cognition, behaviour, hearing, vision and epilepsy. Adverse outcome was defined as death or moderate/severe disability.

RESULTS

Neuroimaging scoring was associated with outcome (p<0.001, area under the curve 0.89±0.03). Isolated WMAs (IWMAs) were present in 61 infants, and WMAs associated with other lesions in 30. Although TPWMAs and diffuse pattern often coexisted in infants with IWMAs (p<0.001), only TPWMAs were associated with adverse outcomes (OR 7.8; 95% CI 1.4 to 42.8), including severe hearing loss in 20% and hearing loss combined with other moderate/severe disabilities in 15%. Increased ADC values were associated with higher neuroimaging scores, WMAs based on visual assessment and IWMAs with TPWMAs. ADC values were not associated with outcome in infants with IWMAs. Findings suggestive of progression of WMAs on follow-up MRI included gliosis and malacia.

CONCLUSIONS

Categorisation of neuroimaging severity correlates with outcome in cCMV. In infants with IWMAs, TPWMAs provide a guide to prognosis.

Incidence and Management of Neonatal Pneumothorax in a 10-Hospital Regional Perinatal Network in Switzerland: A Retrospective Observational Study

OBJECTIVE

 Pneumothorax (PTX) is a potentially life-threatening condition that affects neonates, with an incidence of 0.05 to 2%. Its management includes conservative treatment, chest tube (CT) drainage, and needle aspiration (NA). Aims were to evaluate the incidence of PTX in a 10-hospital perinatal network, its clinical characteristics and risk factors, and to compare the different treatment options.

STUDY DESIGN

 All neonates diagnosed with PTX and hospitalized in the network were included in this retrospective observational trial over a period of 30 months. Primary outcome was the incidence of PTX. Secondary outcomes were the treatment modality, the length of stay (LOS), and the number of chest X-rays.

RESULTS

 Among the 173 neonates included, the overall incidence of PTX was 0.56 per 100 births with a large range among the hospitals (0.12-1.24). Thirty-nine percent of pneumothoraces were treated conservatively, 41% by CT drainage, 13% by NA, and 7% by combined treatment. Failure rate was higher for NA (37%) than for CT drainage (9%). However, the number of X-rays was lower for patients treated by NA, with a median of 6 (interquartile range [IQR] 4-6.25), than by CT drainage, with a median of 9 (IQR 7-12). LOS was shorter for NA than for CT drainage, with a median of 2 (IQR 1-4.25) and 6 days (IQR 3-15), respectively. Complications, including apnea and urinary retention, occurred in 28% of patients managed with CT drainage, whereas none was observed with NA.

CONCLUSION

 High variability of PTX incidence was observed among the hospitals within the network, but these values correspond to the literature. NA showed to reduce the number of X-rays, the LOS, and complications compared with CT drainage, but it carries a high failure rate. This study helped provide a new decisional management algorithm to harmonize and improve PTX treatment within our network.

KEY POINTS

· Neonatal pneumothorax (PTX) is a frequent pathology with a high incidence requiring urgent management.. · We report a large variability of PTX incidence between different hospitals of the same network.. · Needle aspiration carries higher failure rate, shorter hospital stay duration without complications reported..

Cerebral Oximetry Monitoring in Extremely Preterm Infants

BACKGROUND

The use of cerebral oximetry monitoring in the care of extremely preterm infants is increasing. However, evidence that its use improves clinical outcomes is lacking.

METHODS

In this randomized, phase 3 trial conducted at 70 sites in 17 countries, we assigned extremely preterm infants (gestational age, <28 weeks), within 6 hours after birth, to receive treatment guided by cerebral oximetry monitoring for the first 72 hours after birth or to receive usual care. The primary outcome was a composite of death or severe brain injury on cerebral ultrasonography at 36 weeks' postmenstrual age. Serious adverse events that were assessed were death, severe brain injury, bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and late-onset sepsis.

RESULTS

A total of 1601 infants underwent randomization and 1579 (98.6%) were evaluated for the primary outcome. At 36 weeks' postmenstrual age, death or severe brain injury had occurred in 272 of 772 infants (35.2%) in the cerebral oximetry group, as compared with 274 of 807 infants (34.0%) in the usual-care group (relative risk with cerebral oximetry, 1.03; 95% confidence interval, 0.90 to 1.18; P = 0.64). The incidence of serious adverse events did not differ between the two groups.

CONCLUSIONS

In extremely preterm infants, treatment guided by cerebral oximetry monitoring for the first 72 hours after birth was not associated with a lower incidence of death or severe brain injury at 36 weeks' postmenstrual age than usual care. (Funded by the Elsass Foundation and others; SafeBoosC-III ClinicalTrials.gov number, NCT03770741.).

Behavioral outcome of very preterm children at 5 years of age: Prognostic utility of brain tissue volumes at term-equivalent-age, perinatal, and environmental factors

OBJECTIVE

Prematurity is associated with a high risk of long-term behavioral problems. This study aimed to assess the prognostic utility of volumetric brain data at term-equivalent-age (TEA), clinical perinatal factors, and parental social economic risk in the prediction of the behavioral outcome at 5 years in a cohort of very preterm infants (VPT, <32 gestational weeks).

METHODS

T2-weighted magnetic resonance brain images of 80 VPT children were acquired at TEA and automatically segmented into cortical gray matter, deep subcortical gray matter, white matter (WM), cerebellum (CB), and cerebrospinal fluid. The gray matter structure of the amygdala was manually segmented. Children were examined at 5 years of age with a behavioral assessment, using the strengths and difficulties questionnaire (SDQ). The utility of brain volumes at TEA, perinatal factors, and social economic risk for the prediction of behavioral outcome was investigated using support vector machine classifiers and permutation feature importance.

RESULTS

The predictive modeling of the volumetric data showed that WM, amygdala, and CB volumes were the best predictors of the SDQ emotional symptoms score. Among the perinatal factors, sex, sepsis, and bronchopulmonary dysplasia were the best predictors of the hyperactivity/inattention score. When combining the social economic risk with volumetric and perinatal factors, we were able to accurately predict the emotional symptoms score. Finally, social economic risk was positively correlated with the scores of conduct problems and peer problems.

CONCLUSIONS

This study provides information on the relation between brain structure at TEA and clinical perinatal factors with behavioral outcome at age 5 years in VPT children. Nevertheless, the overall predictive power of our models is relatively modest, and further research is needed to identify factors associated with subsequent behavioral problems in this population.

Safety and Short-term Outcomes of High-Dose Erythropoietin in Preterm Infants With Intraventricular Hemorrhage: The EpoRepair Randomized Clinical Trial

IMPORTANCE

Intraventricular hemorrhage (IVH) is a major cause of neonatal morbidity and mortality in preterm infants without a specific medical treatment to date.

OBJECTIVE

To assess the safety and short-term outcomes of high-dose erythropoietin in preterm infants with IVH.

DESIGN, SETTING, AND PARTICIPANTS

Between April 1, 2014, and August 3, 2018, a randomized double-blind clinical trial enrolled 121 preterm infants (gestational age <32 weeks or birth weight <1500 g) aged 8 or less days with moderate to severe IVH identified by cerebral ultrasonography from 8 Swiss and Austrian tertiary neonatal units. Statistical analyses were performed between October 1, 2019, and September 12, 2022.

INTERVENTIONS

Infants received intravenous high-dose erythropoietin (2000 units/kg body weight) or placebo at 4 time points between weeks 1 and 4 of life.

MAIN OUTCOMES AND MEASURES

Secondary outcomes included (1) mortality and morbidity rates and (2) brain magnetic resonance imaging findings at term-equivalent age (TEA). The primary outcome was the composite intelligence quotient at 5 years of age (not available before 2023).

RESULTS

Sixty infants (48% male [n = 29]) were randomly assigned to receive erythropoietin, and 61 infants (61% male [n = 37]) were randomly assigned to receive placebo. The median birth weight was 832 g (IQR, 687-990 g) in the erythropoietin group and 870 g (IQR, 680-1110 g) in the placebo group. Median gestation was 26.1 weeks (IQR, 24.8-27.3 weeks) in the erythropoietin group and 27.0 weeks (24.9-28.1 weeks) in the placebo group. The 2 groups had similar baseline characteristics and morbidities. Up to TEA, 10 newborns died (16.7%) in the erythropoietin group, and 5 newborns (8.2%) died in the placebo group (adjusted odds ratio, 2.24 [95% CI, 0.74-7.66]; P = .15). Infants receiving erythropoietin had higher mean hematocrit levels. Conventional magnetic resonance imaging at TEA for 100 infants showed no significant differences in global or regional brain injury scores.

CONCLUSIONS AND RELEVANCE

This preliminary report of a randomized clinical trial found no evidence that high-dose erythropoietin in preterm infants with IVH affects brain injury scores on conventional magnetic resonance imaging at TEA. Higher mortality in the erythropoietin group was not significant but should be reassessed based on future results from similar trials.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02076373.

Transient tone anomalies in very preterm infants: Association with term-equivalent brain magnetic resonance imaging and neurodevelopment at 18 months

BACKGROUND

Very preterm (VPT) infants are at risk for neurodevelopmental impairments and early clinical findings such as transient tone anomalies (TTA) might represent potential predictive indicators.

AIMS

The aims of this study were to assess 1) the prevalence of TTA at 6 months corrected age in a population of VPT infants, 2) the association with term-equivalent age (TEA) brain MRI and 3) the neurodevelopmental outcome at 18 months corrected age.

STUDY DESIGN AND SUBJECTS

A prospective case-control cohort of 103 VPT infants (<29 weeks of gestation) was followed up at 6 months and classified into TTA+ or TTA-. TTA+ was defined by the presence of ≥2 criteria among anomalies of posture, anomalies of tone and hyperreflexia.

OUTCOME MEASURES

Conventional and diffusion-weighted MRIs at TEA were analyzed according to a semi-quantitative MRI scoring system and apparent diffusion coefficients (ADC) and fractional anisotropy (FA) were measured in frontal, occipital white matter and posterior limb of the internal capsule (PLIC). Neurodevelopment was assessed at 18 months using Bayley-II scales (Psychomotor Developmental Index: PDI; Mental Developmental Index: MDI).

RESULTS

TTA+ infants represented 29.1% of the total population. They had: 1) significantly higher ADC values in 3 regions of interest (p < 0.001), 2) significant lower FA in the PLIC (p < 0.001), and 3) significant lower PDI score (p < 0.05). No differences were observed regarding MDI scores. Interaction of TTA by cerebellum score was related to lower MDI scores.

CONCLUSIONS

In VPT infants, TTA at 6 months and/or structural brain abnormality at TEA are associated with poorer neurodevelopmental outcome at 18 months.

Current Evidence on Cell Death in Preterm Brain Injury in Human and Preclinical Models

Despite tremendous advances in neonatal intensive care over the past 20 years, prematurity carries a high burden of neurological morbidity lasting lifelong. The term encephalopathy of prematurity (EoP) coined by Volpe in 2009 encompasses all aspects of the now known effects of prematurity on the immature brain, including altered and disturbed development as well as specific lesional hallmarks. Understanding the way cells are damaged is crucial to design brain protective strategies, and in this purpose, preclinical models largely contribute to improve the comprehension of the cell death mechanisms. While neuronal cell death has been deeply investigated and characterized in (hypoxic–ischemic) encephalopathy of the newborn at term, little is known about the types of cell death occurring in preterm brain injury. Three main different morphological cell death types are observed in the immature brain, specifically in models of hypoxic–ischemic encephalopathy, namely, necrotic, apoptotic, and autophagic cell death. Features of all three types may be present in the same dying neuron. In preterm brain injury, description of cell death types is sparse, and cell loss primarily concerns immature oligodendrocytes and, infrequently, neurons. In the present review, we first shortly discuss the different main severe preterm brain injury conditions that have been reported to involve cell death, including periventricular leucomalacia (PVL), diffuse white matter injury (dWMI), and intraventricular hemorrhages, as well as potentially harmful iatrogenic conditions linked to premature birth (anesthesia and caffeine therapy). Then, we present an overview of current evidence concerning cell death in both clinical human tissue data and preclinical models by focusing on studies investigating the presence of cell death allowing discriminating between the types of cell death involved. We conclude that, to improve brain protective strategies, not only apoptosis but also other cell death (such as regulated necrotic and autophagic) pathways now need to be investigated together in order to consider all cell death mechanisms involved in the pathogenesis of preterm brain damage.

Enhanced autophagy contributes to excitotoxic lesions in a rat model of preterm brain injury

Cystic periventricular leukomalacia is commonly diagnosed in premature infants, resulting from severe hypoxic-ischemic white matter injury, and also involving some grey matter damage. Very few is known concerning the cell death pathways involved in these types of premature cerebral lesions. Excitotoxicity is a predominant mechanism of hypoxic-ischemic injury in the developing brain. Concomitantly, it has been recently shown that autophagy could be enhanced in excitotoxic conditions switching this physiological intracellular degradation system to a deleterious process. We here investigated the role of autophagy in a validated rodent model of preterm excitotoxic brain damage mimicking in some aspects cystic periventricular leukomalacia. An excitotoxic lesion affecting periventricular white and grey matter was induced by injecting ibotenate, a glutamate analogue, in the subcortical white matter (subcingulum area) of five-day old rat pups. Ibotenate enhanced autophagy in rat brain dying neurons at 24 h as shown by increased presence of autophagosomes (increased LC3-II and LC3-positive dots) and enhanced autophagic degradation (SQSTM1 reduction and increased number and size of lysosomes (LAMP1- and CATHEPSIN B-positive vesicles)). Co-injection of the pharmacological autophagy inhibitor 3-methyladenine prevented not only autophagy induction but also CASPASE-3 activation and calpain-dependent cleavage of SPECTRIN 24 h after the insult, thus providing a strong reduction of the long term brain injury (16 days after ibotenate injection) including lateral ventricle dilatation, decreases in cerebral tissue volume and in subcortical white matter thickness. The autophagy-dependent neuroprotective effect of 3-methyladenine was confirmed in primary cortical neuronal cultures using not only pharmacological but also genetic autophagy inhibition of the ibotenate-induced autophagy. Strategies inhibiting autophagy could then represent a promising neuroprotective approach in the context of severe preterm brain injuries.

Nutrient Intake in the First Two Weeks of Life and Brain Growth in Preterm Neonates

BACKGROUND

Optimizing early nutritional intake in preterm neonates may promote brain health and neurodevelopment through enhanced brain maturation. Our objectives were (1) to determine the association of energy and macronutrient intake in the first 2 weeks of life with regional and total brain growth and white matter (WM) maturation, assessed by 3 serial MRI scans in preterm neonates; (2) to examine how critical illness modifies this association; and (3) to investigate the relationship with neurodevelopmental outcomes.

METHODS

Forty-nine preterm neonates (21 boys, median [interquartile range] gestational age: 27.6 [2.3] weeks) were scanned serially at the following median postmenstrual weeks: 29.4, 31.7, and 41. The total brain, basal nuclei, and cerebellum were semiautomatically segmented. Fractional anisotropy was extracted from diffusion tensor imaging data. Nutritional intake from day of life 1 to 14 was monitored and clinical factors were collected.

RESULTS

Greater energy and lipid intake predicted increased total brain and basal nuclei volumes over the course of neonatal care to term-equivalent age. Similarly, energy and lipid intake were significantly associated with fractional anisotropy values in selected WM tracts. The association of ventilation duration with smaller brain volumes was attenuated by higher energy intake. Brain growth predicted psychomotor outcome at 18 months' corrected age.

CONCLUSIONS

In preterm neonates, greater energy and enteral feeding during the first 2 weeks of life predicted more robust brain growth and accelerated WM maturation. The long-lasting effect of early nutrition on neurodevelopment may be mediated by enhanced brain growth. Optimizing nutrition in preterm neonates may represent a potential avenue to mitigate the adverse brain health consequences of critical illness.

Impact of Early Nutritional Intake on Preterm Brain: A Magnetic Resonance Imaging Study

OBJECTIVES

To investigate the association between early nutritional intake and brain development assessed by magnetic resonance imaging (MRI).

STUDY DESIGN

A cohort of neonates born at ≤30 weeks gestational age underwent MRI at term equivalent age. Brain maturation and injury were assessed using the Kidokoro score. Two groups were defined by severity of the scores. The associations between macronutrients intake during the first 2 weeks of life, clinical factors, and imaging scores were analyzed using logistic regression.

RESULTS

MRI scores from group 1 patients (n = 27) were normal to mildly abnormal (0-5). Group 2 (n = 15) had more abnormal scores (6-12). The median gestational ages (IQR) were 27.4 (1.9) weeks in group 1 and 27.0 (2.9) weeks in group 2, with birth weights of 900 (318) g (group 1) and 844 (293) g (group 2). In group 2, energy, lipid, and carbohydrate intake were significantly lower than in group 1. Group 2 also showed higher rates of sepsis and clinical risk scores than group 1. After adjustments in bivariate models, higher energy and lipid intake remained significantly associated with improved scores on MRI. This association was stronger for the gray matter component of the score.

CONCLUSIONS

Higher energy and lipid intake during the first 2 weeks after birth was associated with a lower incidence of brain lesions and dysmaturation at term equivalent age in preterm neonates.

Neuroprotection by selective neuronal deletion of Atg7 in neonatal brain injury

Perinatal asphyxia induces neuronal cell death and brain injury, and is often associated with irreversible neurological deficits in children. There is an urgent need to elucidate the neuronal death mechanisms occurring after neonatal hypoxia-ischemia (HI). We here investigated the selective neuronal deletion of the Atg7 (autophagy related 7) gene on neuronal cell death and brain injury in a mouse model of severe neonatal hypoxia-ischemia. Neuronal deletion of Atg7 prevented HI-induced autophagy, resulted in 42% decrease of tissue loss compared to wild-type mice after the insult, and reduced cell death in multiple brain regions, including apoptosis, as shown by decreased caspase-dependent and -independent cell death. Moreover, we investigated the lentiform nucleus of human newborns who died after severe perinatal asphyxia and found increased neuronal autophagy after severe hypoxic-ischemic encephalopathy compared to control uninjured brains, as indicated by the numbers of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3)-, LAMP1 (lysosomal-associated membrane protein 1)-, and CTSD (cathepsin D)-positive cells. These findings reveal that selective neuronal deletion of Atg7 is strongly protective against neuronal death and overall brain injury occurring after HI and suggest that inhibition of HI-enhanced autophagy should be considered as a potential therapeutic target for the treatment of human newborns developing severe hypoxic-ischemic encephalopathy.

Evolution of T1 Relaxation, ADC, and Fractional Anisotropy during Early Brain Maturation: A Serial Imaging Study on Preterm Infants

BACKGROUND AND PURPOSE

The alteration of brain maturation in preterm infants contributes to neurodevelopmental disabilities during childhood. Serial imaging allows understanding of the mechanisms leading to dysmaturation in the preterm brain. The purpose of the present study was to provide reference quantitative MR imaging measures across time in preterm infants, by using ADC, fractional anisotropy, and T1 maps obtained by using the magnetization-prepared dual rapid acquisition of gradient echo technique.

MATERIALS AND METHODS

We included preterm neonates born at <30 weeks of gestational age without major brain lesions on early cranial sonography and performed 3 MRIs (3T) from birth to term-equivalent age. Multiple measurements (ADC, fractional anisotropy, and T1 relaxation) were performed on each examination in 12 defined white and gray matter ROIs.

RESULTS

We acquired 107 MRIs (35 early, 33 intermediary, and 39 at term-equivalent age) in 39 cerebral low-risk preterm infants. Measures of T1 relaxation time showed a gradual and significant decrease with time in a region- and hemispheric-specific manner. ADC values showed a similar decline with time, but with more variability than T1 relaxation. An increase of fractional anisotropy values was observed in WM regions and inversely a decrease in the cortex.

CONCLUSIONS

The gradual change with time reflects the progressive maturation of the cerebral microstructure in white and gray matter. Our study provides reference trajectories from 25 to 40 weeks of gestation of T1 relaxation, ADC, and fractional anisotropy values in low-risk preterm infants. We speculate that deviation thereof might reflect disturbed cerebral maturation; the correlation of this disturbed maturation with neurodevelopmental outcome remains to be addressed.

Neuronal death after perinatal cerebral hypoxia-ischemia: Focus on autophagy-mediated cell death

Neonatal hypoxic-ischemic encephalopathy is a critical cerebral event occurring around birth with high mortality and neurological morbidity associated with long-term invalidating sequelae. In view of the great clinical importance of this condition and the lack of very efficacious neuroprotective strategies, it is urgent to better understand the different cell death mechanisms involved with the ultimate aim of developing new therapeutic approaches. The morphological features of three different cell death types can be observed in models of perinatal cerebral hypoxia-ischemia: necrotic, apoptotic and autophagic cell death. They may be combined in the same dying neuron. In the present review, we discuss the different cell death mechanisms involved in neonatal cerebral hypoxia-ischemia with a special focus on how autophagy may be involved in neuronal death, based: (1) on experimental models of perinatal hypoxia-ischemia and stroke, and (2) on the brains of human neonates who suffered from neonatal hypoxia-ischemia.

Subplate in a rat model of preterm hypoxia-ischemia

Objective

Hypoxia–ischemia (HI) in preterm infants primarily leads to injuries in the cerebral white matter. However, there is growing evidence that perinatal injury in preterms can also involve other zones including the cortical gray matter. In a neonatal rat model of HI, selective vulnerability of subplate has been suggested using BrdU birth-dating methods. In this study, we aimed to investigate the neuropathological changes of the subplate and deep layers of the cortex following cerebral HI in neonatal rats with specific cell markers.

Methods

P2 rats underwent permanent occlusion of the right common carotid artery followed by a period of hypoxia. P8 rats were analyzed using immunohistochemistry; subplate and deep layers cells were quantified and compared with sham-operated case.

Results

A large variability in the extent of the cerebral injury was apparent. For the three analyzed subplate populations (Nurr1+, Cplx3+, and Ctgf+ cells), no significant cell reduction was observed in mild and moderate cases. Only in severe cases, subplate cells were strongly affected, but these injuries were always accompanied by the cell reductions in layers VI and V.

Interpretation

We could therefore not confirm a specific vulnerability of subplate cells compared to other deep layers or the white matter in our model.

Dying neurons in thalamus of asphyxiated term newborns and rats are autophagic

OBJECTIVE

Neonatal hypoxic-ischemic encephalopathy (HIE) still carries a high burden by its mortality and long-term neurological morbidity in survivors. Apart from hypothermia, there is no acknowledged therapy for HIE, reflecting the lack of mechanistic understanding of its pathophysiology. (Macro)autophagy, a physiological intracellular process of lysosomal degradation, has been proposed to be excessively activated in excitotoxic conditions such as HIE. The present study examines whether neuronal autophagy in the thalamus of asphyxiated human newborns or P7 rats is enhanced and related to neuronal death processes.

METHODS

Neuronal autophagy and cell death were evaluated in the thalamus (frequently injured in severe HIE) of both human newborns who died after severe HIE (n = 5) and P7 hypoxic-ischemic rats (Rice-Vannuci model). Autophagic (LC3, p62), lysosomal (LAMP1, cathepsins), and cell death (TUNEL, caspase-3) markers were studied by immunohistochemistry in human and rat brain sections, and by additional methods in rats (immunoblotting, histochemistry, and electron microscopy).

RESULTS

Following severe perinatal asphyxia in both humans and rats, thalamic neurons displayed up to 10-fold (p < 0.001) higher numbers of autophagosomes and lysosomes, implying an enhanced autophagic flux. The highly autophagic neurons presented strong features of apoptosis. These findings were confirmed and elucidated in more detail in rats.

INTERPRETATION

These results show for the first time that autophagy is enhanced in severe HIE in dying thalamic neurons of human newborns, as in rats. Experimental neuroprotective strategies targeting autophagy could thus be a promising lead to follow for the development of future therapeutic approaches.

Involvement of autophagy in hypoxic-excitotoxic neuronal death

Neuronal autophagy is increased in numerous excitotoxic conditions including neonatal cerebral hypoxia-ischemia (HI). However, the role of this HI-induced autophagy remains unclear. To clarify this role we established an in vitro model of excitotoxicity combining kainate treatment (Ka, 30 µM) with hypoxia (Hx, 6% oxygen) in primary neuron cultures. KaHx rapidly induced excitotoxic death that was completely prevented by MK801 or EGTA. KaHx also stimulated neuronal autophagic flux as shown by a rise in autophagosome number (increased levels of LC3-II and punctate LC3 labeling) accompanied by increases in lysosomal abundance and activity (increased SQSTM1/p62 degradation, and increased LC3-II levels in the presence of lysosomal inhibitors) and fusion (shown using an RFP-GFP-LC3 reporter). To determine the role of the enhanced autophagy we applied either pharmacological autophagy inhibitors (3-methyladenine or pepstatinA/E64) or lentiviral vectors delivering shRNAs targeting Becn1 or Atg7. Both strategies reduced KaHx-induced neuronal death. A prodeath role of autophagy was also confirmed by the enhanced toxicity of KaHx in cultures overexpressing BECN1 or ATG7. Finally, in vivo inhibition of autophagy by intrastriatal injection of a lentiviral vector expressing a Becn1-targeting shRNA increased the volume of intact striatum in a rat model of severe neonatal cerebral HI. These results clearly show a death-mediating role of autophagy in hypoxic-excitotoxic conditions and suggest that inhibition of autophagy should be considered as a neuroprotective strategy in HI brain injuries.

[Cerebral brain injury in preterm infants and the role of neuroimaging in predicting neurodevelopmental outcomes]

Due to advances in neonatal intensive care over the last decades, the pattern of brain injury seen in very preterm infants has evolved in more subtle lesions that are still essential to diagnose in regard to neurodevelopmental outcome. While cranial ultrasound is still used at the bedside, magnetic resonance imaging (MRI) is becoming increasingly used in this population for the assessment of brain maturation and white and grey matter lesions. Therefore, MRI provides a better prognostic value for the neurodevelopmental outcome of these preterms. Furthermore, the development of new MRI techniques, such as diffusion tensor imaging, resting state functional connectivity and magnetic resonance spectroscopy, may further increase the prognostic value, helping to counsel parents and allocate early intervention services.

Neurodevelopment outcome of newborns with cerebral subependymal pseudocysts at 18 and 46 months: a prospective study

OBJECTIVES

Subependymal pseudocysts (SEPC) are cerebral periventricular cysts located on the floor of the lateral ventricle and result from regression of the germinal matrix. They are increasingly diagnosed on neonatal cranial ultrasound. While associated pathologies are reported, information about long-term prognosis is missing, and we aimed to investigate long-term follow-up of these patients.

STUDY DESIGN

Newborns diagnosed with SEPC were enrolled for follow-up. Neurodevelopment outcome was assessed at 6, 18 and 46 months of age.

RESULTS

74 newborns were recruited: we found a high rate of antenatal events (63%), premature infants (66% <37 weeks, 31% <32 weeks) and twins (30%). MRI was performed in 31 patients, and cystic periventricular leukomalacia (c-PVL) was primarily falsely diagnosed in 9 of them. Underlying disease was diagnosed in 17 patients, 8 with congenital cytomegalovirus (CMV) infection, 5 with genetic and 4 with metabolic disease. Neurological examination (NE) at birth was normal for patients with SEPCs and no underlying disease, except one. Mean Developmental Quotient and IQ of these patients was 98.2 (±9.6SD; range 77-121), 94.6 (±14.2SD; 71-120) and 99.6 (±12.3SD; 76-120) at 6, 18 and 46 months of age, respectively, with no differences between the subtypes of SEPC. A subset analysis showed no outcome differences between preterm infants with or without SEPC, or between preterm of <32 GA and ≥32 GA.

CONCLUSIONS

Neurodevelopment of newborns with SEPC was normal when no underlying disease was present. This study suggests that if NE is normal at birth and congenital CMV infection can be excluded, then no further investigations are needed. Moreover, it is crucial to differentiate SEPC from c-PVL which carries a poor prognosis.

[Pediatrics]

Several preliminary studies suggest that prophylactic administration of probiotics reduces the incidence of necrotizing enterocolitis (NEC) in preterm infants, and several neonatology units have introduced this treatment under strict surveillance. Nonetheless, breast milk feeding remains the mainstay of NEC prevention. The beta-blocker propranolol, known for its effectiveness on cutaneous hemangiomas, is also proving useful for the treatment of subglottic or visceral hemangiomas. Following the decrease in severe bacterial infections thanks to widespread vaccinations, the McCarthy clinical score has regained importance in the prediction of the risk of bacterial infection in febrile infants. It is easy to use, economical, and has a diagnostic value comparable to laboratory tests. The new WHO growth charts have been introduced in Switzerland in 2011 to take into account the increasing regional and ethnic variations in our country. Any significant change in growth velocity should prompt an evaluation of the need of further investigations.

Development of cystic periventricular leukomalacia in newborn infants after rotavirus infection

We describe 5 preterm and 3 term infants who presented with seizures during rotavirus infection within 6 weeks after birth. Six of these infants developed late-onset cystic periventricular leukomalacia. Four of the preterm infants had neurodevelopmental delay, and 4 (near) term infants had normal early outcome.

Perinatal care at the limit of viability between 22 and 26 completed weeks of gestation in Switzerland. 2011 revision of the Swiss recommendations

Perinatal care of pregnant women at high risk for preterm delivery and of preterm infants born at the limit of viability (22-26 completed weeks of gestation) requires a multidisciplinary approach by an experienced perinatal team. Limited precision in the determination of both gestational age and foetal weight, as well as biological variability may significantly affect the course of action chosen in individual cases. The decisions that must be taken with the pregnant women and on behalf of the preterm infant in this context are complex and have far-reaching consequences. When counselling pregnant women and their partners, neonatologists and obstetricians should provide them with comprehensive information in a sensitive and supportive way to build a basis of trust. The decisions are developed in a continuing dialogue between all parties involved (physicians, midwives, nursing staff and parents) with the principal aim to find solutions that are in the infant's and pregnant woman's best interest. Knowledge of current gestational age-specific mortality and morbidity rates and how they are modified by prenatally known prognostic factors (estimated foetal weight, sex, exposure or nonexposure to antenatal corticosteroids, single or multiple births) as well as the application of accepted ethical principles form the basis for responsible decision-making. Communication between all parties involved plays a central role. The members of the interdisciplinary working group suggest that the care of preterm infants with a gestational age between 22 0/7 and 23 6/7 weeks should generally be limited to palliative care. Obstetric interventions for foetal indications such as Caesarean section delivery are usually not indicated. In selected cases, for example, after 23 weeks of pregnancy have been completed and several of the above mentioned prenatally known prognostic factors are favourable or well informed parents insist on the initiation of life-sustaining therapies, active obstetric interventions for foetal indications and provisional intensive care of the neonate may be reasonable. In preterm infants with a gestational age between 24 0/7 and 24 6/7 weeks, it can be difficult to determine whether the burden of obstetric interventions and neonatal intensive care is justified given the limited chances of success of such a therapy. In such cases, the individual constellation of prenatally known factors which impact on prognosis can be helpful in the decision making process with the parents. In preterm infants with a gestational age between 25 0/7 and 25 6/7 weeks, foetal surveillance, obstetric interventions for foetal indications and neonatal intensive care measures are generally indicated. However, if several prenatally known prognostic factors are unfavourable and the parents agree, primary non-intervention and neonatal palliative care can be considered. All pregnant women with threatening preterm delivery or premature rupture of membranes at the limit of viability must be transferred to a perinatal centre with a level III neonatal intensive care unit no later than 23 0/7 weeks of gestation, unless emergency delivery is indicated. An experienced neonatology team should be involved in all deliveries that take place after 23 0/7 weeks of gestation to help to decide together with the parents if the initiation of intensive care measures appears to be appropriate or if preference should be given to palliative care (i.e., primary non-intervention). In doubtful situations, it can be reasonable to initiate intensive care and to admit the preterm infant to a neonatal intensive care unit (i.e., provisional intensive care). The infant's clinical evolution and additional discussions with the parents will help to clarify whether the life-sustaining therapies should be continued or withdrawn. Life support is continued as long as there is reasonable hope for survival and the infant's burden of intensive care is acceptable. If, on the other hand, the health care team and the parents have to recognise that in the light of a very poor prognosis the burden of the currently used therapies has become disproportionate, intensive care measures are no longer justified and other aspects of care (e.g., relief of pain and suffering) are the new priorities (i.e., redirection of care). If a decision is made to withhold or withdraw life-sustaining therapies, the health care team should focus on comfort care for the dying infant and support for the parents.

Beclin 1-independent autophagy contributes to apoptosis in cortical neurons

Neuronal autophagy is enhanced in many neurological conditions, such as cerebral ischemia and traumatic brain injury, but its role in associated neuronal death is controversial, especially under conditions of apoptosis. We therefore investigated the role of autophagy in the apoptosis of primary cortical neurons treated with the widely used and potent pro-apoptotic agent, staurosporine (STS). Even before apoptosis, STS enhanced autophagic flux, as shown by increases in autophagosomal (LC3-II level, LC3 punctate labeling) and lysosomal (cathepsin D, LAMP1, acid phosphatase, β-hexasominidase) markers. Inhibition of autophagy by 3-methyladenine, or by lentivirally-delivered shRNAs against Atg5 and Atg7, strongly reduced the STS-induced activation of caspase-3 and nuclear translocation of AIF, and gave partial protection against neuronal death. Pan-caspase inhibition with Q-VD-OPH likewise protected partially against neuronal death, but failed to affect autophagy. Combined inhibition of both autophagy and caspases gave strong synergistic neuroprotection. The autophagy contributing to apoptosis was Beclin 1-independent, as shown by the fact that Beclin 1 knockdown failed to reduce it but efficiently reduced rapamycin-induced autophagy. Moreover the Beclin 1 knockdown sensitized neurons to STS-induced apoptosis, indicating a cytoprotective role of Beclin 1 in cortical neurons. Caspase-3 activation and pyknosis induced by two other pro-apoptotic stimuli, MK801 and etoposide, were likewise found to be associated with Beclin 1-independent autophagy and reduced by the knockdown of Atg7 but not Beclin 1. In conclusion, Beclin 1-independent autophagy is an important contributor to both the caspase-dependent and -independent components of neuronal apoptosis and may be considered as an important therapeutic target in neural conditions involving apoptosis.

Neuronal autophagy as a mediator of life and death: contrasting roles in chronic neurodegenerative and acute neural disorders

Autophagy is a cellular mechanism for degrading proteins and organelles. It was first described as a physiological process essential for cellular health and survival, and this is its role in most cells. However, it can also be a mediator of cell death, either by the triggering of apoptosis or by an independent "autophagic" cell death mechanism. This duality is important in the central nervous system, where the activation of autophagy has recently been shown to be protective in certain chronic neurodegenerative diseases but deleterious in acute neural disorders such as stroke and hypoxic/ischemic injury. The authors here discuss these distinct roles of autophagy in the nervous system with a focus on the role of autophagy in mediating neuronal death. The development of new therapeutic strategies based on the manipulation of autophagy will need to take into account these opposing roles of autophagy.

Enhancement of autophagic flux after neonatal cerebral hypoxia-ischemia and its region-specific relationship to apoptotic mechanisms

The multiplicity of cell death mechanisms induced by neonatal hypoxia-ischemia makes neuroprotective treatment against neonatal asphyxia more difficult to achieve. Whereas the roles of apoptosis and necrosis in such conditions have been studied intensively, the implication of autophagic cell death has only recently been considered. Here, we used the most clinically relevant rodent model of perinatal asphyxia to investigate the involvement of autophagy in hypoxic-ischemic brain injury. Seven-day-old rats underwent permanent ligation of the right common carotid artery, followed by 2 hours of hypoxia. This condition not only increased autophagosomal abundance (increase in microtubule-associated protein 1 light chain 3-11 level and punctuate labeling) but also lysosomal activities (cathepsin D, acid phosphatase, and beta-N-acetylhexosaminidase) in cortical and hippocampal CA3-damaged neurons at 6 and 24 hours, demonstrating an increase in the autophagic flux. In the cortex, this enhanced autophagy may be related to apoptosis since some neurons presenting a high level of autophagy also expressed apoptotic features, including cleaved caspase-3. On the other hand, enhanced autophagy in CA3 was associated with a more purely autophagic cell death phenotype. In striking contrast to CA3 neurons, those in CA1 presented only a minimal increase in autophagy but strong apoptotic characteristics. These results suggest a role of enhanced autophagy in delayed neuronal death after severe hypoxia-ischemia that is differentially linked to apoptosis according to the cerebral region.

Atypical presentation of Prader-Willi syndrome with cerebral venous thrombosis: association or fortuity?

A newborn female born at term was admitted at 28 hours for seizures and generalized hypotonia. Cerebral ultrasound showed a right temporal echogenic lesion confirmed on MRI and thought to be secondary to thrombosis of the vein of Labbé. The EEG showed epileptic discharges over the right temporal region. Extensive thrombotic studies revealed a transiently decreased PTT consistent with a prothrombotic state. The hypotonia did not resolve after the acute phase as expected, raising the possibility of another underlying cause. Because of a peculiar phenotype with almond-shaped eyes and bitemporal depression, Prader-Willi syndrome (PWS) was suspected. Methylation analysis confirmed PWS, FISH analysis excluded a deletion in 15q11-q13, maternal uniparental disomy (UPD) was confirmed. To our knowledge, this is the first report of the association of a neonatal venous thrombosis and a PW Syndrome.

Effect of hypoxia on protein phosphatase 2A activity, subcellular distribution and expression in cerebral cortex of newborn piglets

Protein phosphatase (PP) 2A (PP2A), a major serine/threonine phosphatase highly active in the brain, is known to regulate programmed cell death by different mechanisms including downregulation of Ca++/calmodulin-dependent kinase IV (CaMK IV). Previous studies have shown that CaMK IV activity is increased following cerebral hypoxia. In the present study, we tested the hypothesis that PP2A activity and expression in neuronal nuclei are decreased following hypoxia in newborn piglets. PP and PP2A activities were determined in cerebral subcellular fractions spectrophotometrically using a serine phosphopeptide in the presence or absence of microcystine. The activity of CaMK IV in neuronal nuclei was determined by 33P-incorporation into syntide 2 in the presence or absence of either 1 mM EGTA or 0.8 mM CaCl2 and 1 mM calmodulin. The expressions of PP2A and CaMK IV were measured using Western blot. Following hypoxia, nuclear Ca++-dependent kinase IV activity increased two-fold (P<0.001), whereas PP2A and PP activities significantly decreased (P<0.05) in the neuronal nuclei and membranes but not in the cytosol (P=NS). The distribution of the activity of PP2A was 60% in the cytosol, 35% in membranes and 5% in the neuronal nuclei. The expression of PP2A protein showed a 14% increase and for CaMK IV protein a 100% increase during hypoxia. We propose that due to the decreased activity of PP and PP2A following hypoxia in the neuronal nuclei there is a shift in the balance of the phosphorylation/dephosphorylation system toward increased phosphorylated state thereby increasing activity of the nuclear CaMK IV, modulator of programmed cell death. Since there is only slight increase in the PP2A protein expression, we conclude that the changes observed in the activity of PP2A are due to hypoxia-induced modification of the enzyme itself. We also provide evidence that PP2A is a potential regulator of CaMK IV during hypoxia.

Maintenance hemodialysis and circulating ionized magnesium

BACKGROUND

Circulating magnesium exists in the bound and in the free ionized form, that is biologically active. In kidney disease the relationship between ionized and total circulating magnesium is often altered. Little information is available on the influence of hemodialysis on the relationship between ionized and total circulating magnesium in end-stage kidney disease.

METHODS

Plasma total and ionized magnesium and the plasma ionized magnesium fraction were assessed before and after hemodialysis (dialysate magnesium content 0.75 mmol/l) in 46 patients with end-stage kidney disease and in a control group of 25 healthy subjects.

RESULTS

In patients plasma total (from 1.19 [1.05-1.33] to 1.10 [1.02-1.16] mmol/l; median and interquartile range) and ionized (from 0.71 [0.66-0.78] to 0.65 [0.63-0.69] mmol/l) magnesium significantly decreased during dialysis (control subjects: 0.82 [0.80-0.92], respectively, 0.57 [0.54-0.59] mmol/l). The plasma ionized magnesium fraction was significantly lower in patients both before (0.61 [0.58-0.64)] and after (0.60 [0.56-0.62]) hemodialysis than in controls (0.68 [0.65-0.70]).

CONCLUSIONS

The study demonstrates a tendency towards a reduced circulating ionized magnesium fraction in end-stage kidney disease that is not corrected by hemodialysis.

Long-term calcineurin inhibition and magnesium balance after renal transplantation

Regulation of magnesium balance is achieved by a steady-state mechanism in which intake and output are maintained at an equal level. Dietary magnesium intake, total and ionized plasma magnesium levels, and urinary magnesium were assessed in 46 renal transplant recipients treated with cyclosporine, nine transplant recipients who had never been on cyclosporine, and 31 healthy volunteers. Dietary magnesium intake [13.5 (11.0-15.1) mmol/day vs 13.0 (11.1-16.0) mmol/day and 13.7 (11.4-16.7) mmol/day, respectively; median and interquartile range] and urinary magnesium excretion [4.31 (3.57-5.89) vs 4.39 (3.56-6.02) and 5.01 (3.73-6.01) mmol/day, respectively] were similar in renal transplant recipients treated with cyclosporine, transplant recipients who had never been on cyclosporine, and control subjects. Total [0.74 (0.70-0.78) vs 0.80 (0.74-0.84) and 0.81 (0.79-0.87) mmol/l), respectively] and ionized [0.49 (0.46-0.52) vs 0.53 (0.50-0.58) and 0.54 (0.52-0.59) mmol/l, respectively] plasma magnesium were significantly lower in renal transplant recipients on cyclosporine than in transplant recipients without cyclosporine, and healthy controls. These observations indicate a modified magnesium steady state in renal transplant recipients treated with cyclosporine.

Postnatal gender-dependent maturation of cellular cysteine uptake

BACKGROUND

In view of the functional capacity of glutathione synthesis in premature infants, and because the availability of cysteine is one the rate limiting steps in glutathione synthesis, we hypothesized that the low glutathione levels in premature infants may be due to immaturity of the active cellular uptake of cysteine.

OBJECTIVE

To document in cells from newborn infants the effect of maturity and gender on cysteine uptake and consequently on glutathione levels.

METHODS

Incorporation of L-[35S] cysteine was measured in leukocytes from cord blood and from tracheal aspirates (TAC) of newborn infants of varying (gestational as well as postnatal) ages and gender. Cysteine uptake was correlated with glutathione in TAC.

RESULTS

The maturity of newborn girls positively influences cysteine uptake, which is responsible for 78% of the variation in their glutathione content. However, in newborn boys, gestational and postnatal ages did not influence the cysteine uptake.

DISCUSSION

Cysteine uptake appears to be the limiting step explaining the reported gender-related differences in glutathione as well as the low levels of this central antioxidant found in premature infants. The immature cysteine uptake found in cells from premature infants raises questions about the bioavailability of this conditionally essential amino acid in regimens of parenteral nutrition for human neonates.

Circulating sodium in acute meningitis

BACKGROUND

In acute meningitis hyponatremia is common and traditionally attributed exclusively to inappropriate water retention. However, the exact mechanisms underlying hyponatremia are unknown.

METHODS

The files of 300 pediatric patients with acute bacterial (n = 190) or aseptic (n = 110) meningitides were retrospectively analyzed.

RESULTS

The plasma sodium level ranged from 122 to 148 mmol/l and was low (<133 mmol/l) in 97 patients. Fluid volume contraction was significantly more pronounced in hyponatremia (median 6.0. 10(-2)) than in normonatremia (median 2.0. 10(-2)). The fractional sodium excretion was less than 1.00. 10(-2) in the 26 hyponatremic children with this measurement.

CONCLUSION

In acute meningitis hyponatremia is not exclusively brought about by inappropriate water retention.

Circulating ionized and total magnesium in end-stage kidney disease

BACKGROUND

Circulating magnesium exists in the ionized state and in the undissociated form, either bound to albumin, or complexed to various anions. Until recently, only the measurement of total plasma magnesium has been possible. Now circulating ionized magnesium can be assessed as well.

METHODS

Total and ionized plasma magnesium were determined in 43 patients on maintenance hemodialysis (dialysate composition: calcium 1.75 mmol/l, magnesium 0.75 mmol/l) before a dialysis session and in a group of 23 healthy subjects.

RESULTS

The total (1.16 [1.03-1.31] versus 0.81 [0.78-0.89] mmol/l; median and interquartile range) and the ionized (0.71 [0.66-0.78] versus 0.54 [0.53-0.59] mmol/l) plasma magnesium levels were significantly higher (p < 0.01) and the ionized plasma magnesium fraction lower (0.61 [0.58-0.65] versus 0.67 [0.64-0.70]; p < 0.02) in patients than in controls.

CONCLUSION

The determination of circulating ionized magnesium using selective electrodes is an attractive method to evaluate extracellular magnesium in kidney disease.

Free circulating magnesium and renal magnesium handling during acute metabolic acidosis in humans

Ion-selective electrodes have been designed for determining the ionized concentration of magnesium in blood, the biologically active form of this ion. The effect of acute acidosis induced by ammonium loading on circulating and urinary magnesium was investigated in 11 volunteers. No changes in plasma total and ionized magnesium were noted following administration of ammonium chloride. On the contrary, administration of ammonium chloride increased the plasma free magnesium fraction and the urinary magnesium excretion. The study demonstrates that the hypermagnesiuria induced by acute acidosis is not caused by ionized hypermagnesemia and supports the theory that acidosis decreases the circulating magnesium fraction that is bound to proteins.

Childhood insulin-dependent diabetes mellitus: initial presentation and management in the nineties

Diabetes mellitus with onset during childhood usually presents as overt ketoacidemia. Pediatricians now inquire specifically about diabetes mellitus in children with nonspecific signs of illness and perform urinary dipstick testing. The present study was therefore performed to assess the possible influence of this strategy on the initial presentation and management of diabetes mellitus. The charts of 61 consecutive children with newly diagnosed diabetes mellitus (positive glucosuria and ketonuria and capillary glucose >14 mmol/l), who had been admitted between 1991 and 1996 at the Department of Pediatrics, University of Bern, Switzerland, were therefore reviewed. Twenty-six out of the 61 patients were nonacidemic (blood pH 7.36 or more). Children with and without acidemia did not differ with respect to age, history of polydipsia and polyuria, plasma glucose and circulating glycated hemoglobin A1c. The degree of dehydration and the amount of fluid required for its correction and the total insulin dosage were more prominent in the group of patients with acidemia. The study demonstrates that childhood diabetes mellitus is nowadays often recognized as nonacidemic hyperglycemia and that in these patients a reduced initial fluid repair and total insulin dosage is recommended.

Aminoglycosides and renal magnesium homeostasis in humans

BACKGROUND

The use of aminoglycosides has been linked with hypomagnesaemia in scattered reports. The objective of the study was to measure prospectively the effect of treatment with the aminoglycoside amikacin on renal magnesium homeostasis.

METHODS

Twenty-four cystic fibrosis patients (aged 9-19 years) admitted because of exacerbation of pulmonary symptoms caused by Pseudomonas aeruginosa were treated with the aminoglycoside amikacin and the cephalosporin ceftazidime for 14 days. Renal values and plasma and urinary electrolytes were measured before and at the end of the systemic anti-pseudomonal therapy.

RESULTS

In the patients with cystic fibrosis, treatment with amikacin and ceftazidime did not modify plasma creatinine or urea and plasma or urinary sodium, potassium and calcium. Treatment with amikacin and ceftazidime significantly decreased both plasma total magnesium (from 0.77 (0. 74-0.81) to 0.73 (0.71-75) mmol/l; median and interquartile range) and ionized magnesium (from 0.53 (0.50-0.55) to 0.50 (0.47-0.52) mmol/l) concentration and increased fractional urinary magnesium excretion (from 0.0568 (0.0494-0.0716) to 0.0721 (0.0630-0.111)) and total urinary magnesium excretion (from 30.7 (26.5-38.0) to 38.5 (31. 5-49.0) micromol/l glomerular filtration rate).

CONCLUSIONS

The present study demonstrates that systemic therapy with amikacin plus ceftazidime causes mild hypomagnesaemia secondary to renal magnesium wasting even in the absence of a significant rise in circulating creatinine and urea.

Hypomagnesaemia-hypercalciuria-nephrocalcinosis: a report of nine cases and a review

BACKGROUND

The cardinal characteristics of primary hypomagnesaemia-hypercalciuria-nephrocalcinosis include renal magnesium wasting, marked hypercalciuria, renal stones, nephrocalcinosis, a tendency towards chronic renal insufficiency and sometimes even ocular abnormalities or hearing impairment.

METHODS

As very few patients with this syndrome have been described, we provide information on nine patients on follow-up at our institutions and review the 42 cases reported in the literature (33 females and 18 males).

RESULTS

Urinary tract infections, polyuria-polydipsia, renal stones and tetanic convulsions were the main clinical findings at diagnosis. The clinical course was highly variable; renal failure was often reported. The concomitant occurrence of ocular involvement or hearing impairment was reported in a large subset of patients. Parental consanguinity was noted in some families.

CONCLUSIONS

The results indicate an autosomal recessive inheritance. The diagnosis of primary hypomagnesaemia-hypercalciuria-nephrocalcinosis deserves consideration in any patient with nephrocalcinosis and hypercalciuria.

Pulmonary renal syndrome in childhood: a report of twenty-one cases and a review of the literature

In adults, the term specific pulmonary renal syndrome describes disorders with pulmonary and glomerular manifestations and includes Wegener's granulomatosis, Goodpasture disease, and systemic lupus erythematosus. Nonspecific pulmonary renal syndrome refers to either pulmonary disease complicating glomerular disease, or glomerular diseases following pulmonary disease. Since little is known regarding pulmonary renal syndrome in childhood, we reviewed the charts of 21 pediatric patients with pulmonary renal syndromes treated by the Department of Pediatrics, University of Bern between 1991 and 1998; we also reviewed the pediatric literature that deals with specific pulmonary renal syndromes. Specific pulmonary renal syndrome was noted in 3 children with systemic vasculitis (Wegener granulomatosis, N = 2; microscopic polyangiitis, N = 1) and 2 with systemic lupus erythematosus. Nonspecific pulmonary renal syndrome was observed in 12 patients with pulmonary edema (N = 9), pulmonary thromboembolism (N = 2), and pulmonary infection (N = 1) complicating the course of a glomerular disease, and in 4 children with a pulmonary disease followed by a glomerular disease. Review of the literature disclosed 52 cases of specific pulmonary renal syndrome other than systemic lupus erythematosus: Wegener granulomatosis (N = 28), Goodpasture disease (N = 13), and Henoch-Schönlein purpura (N = 11). In addition, hemolytic uremic syndrome complicated pneumococcal pneumonia in 32 cases. We conclude that pulmonary renal syndromes need to be looked for in childhood. Apart from Wegener granulomatosis, Goodpasture disease, and systemic lupus erythematosus, Henoch-Schönlein purpura and hemolytic-uremic syndrome occasionally have both pulmonary and renal features.

Free and total circulating magnesium following glucagon injection in humans

It has been postulated that parathormone, calcitonine, insulin and catecholamines are involved in extracellular magnesium homeostasis. Yet, there is still a rudimentary knowledge of the endocrine factors that control circulating magnesium homeostasis. The effects of exogenous glucagon injection on circulating total and ionized magnesium were investigated in 11 healthy humans (five females and six males, aged between 21 and 30, median 26 years). As compared with a control study, intravenous injection of a bolus of 1 mg of glucagon was associated with the expected raised glucose (at 5, 10, 20 and 30 min) and with decreased potassium (at 20 and 30 min) and inorganic phosphate (at 20 and 30 min) levels. Intravenous glucagon was not followed by significant changes in plasma total and ionized magnesium. Consequently, there is still little evidence for a glucagon-dependent control of the extracellular magnesium concentration after acute administration of glucagon.

Permanently reduced plasma ionized magnesium among renal transplant recipients on cyclosporine

Hypomagnesemia is common after kidney transplantation. Until recently, only the determination of total plasma magnesium was possible, whereas the assessment of ionized magnesium has since become practicable. One hundred and nine renal transplant patients on cyclosporine with allografts functioning stably for more than 6 months and plasma creatinine levels of less than 200 micromol/l entered the study. Total and ionized circulating magnesium were assessed among these 109 patients, as well as among 15 renal transplant patients not on cyclosporine and 21 healthy volunteers. Cyclosporine patients showed significantly lower total and ionized circulating magnesium values than the two control groups. Plasma total and ionized magnesium levels were also significantly lower among cyclosporine patients treated concurrently with insulin or oral hypoglycemic agents than among those who were not. No correlation was noted between time after transplantation and plasma magnesium with respect to patients on cyclosporine. In conclusion, the study demonstrates that a large subset of renal transplant patients treated with cyclosporine have permanent deficiencies of ionized and total magnesium. The tendency towards hypomagnesemia is also more pronounced among patients with diabetes mellitus.