Effect of cardiac compressions and hypothermia treatment on cardiac troponin I in newborns with perinatal asphyxia.

BACKGROUND: The American Heart Association, the European Resuscitation and the International Liaison Committee issued new neonatal resuscitation guidelines (2010) where therapeutic hypothermia is introduced after hypoxic-ischaemic encephalopathy (HIE) in term infants to prevent brain injury. Our study aimed to investigate whether hypothermia can reduce the release of a cardiac cellular marker, cardiac troponin I (cTnI), in HIE infants compared to normothermia care, if cTnI can be used as a prognostic marker for long term neuro-developmental outcome and if cardiac compression at birth affects the level of cTnI. METHODS: We retrospectively collected resuscitation data at birth and cTnI levels for the first 3 days in HIE infants who fulfilled cooling entry criteria. These infants received either normothermia care or induced hypothermia treatment in the neonatal period and were then followed up and tested by standard cognitive and motor assessments. The outcome is defined as death, disability or good. RESULTS: We confirmed an increase in cTnI after cardiac compressions (p=0.003, Mann-Whitney test). We found that hypothermia significantly reduced the release of cTnI (peak level and area under the curve within 24h of age), p=0.002, linear regression. Receiver operating characteristic curves showed a level of cTnI at 24 h of age <0.22 ng/ml for normothermic and <0.15 ng/ml for hypothermic infants predicts a good outcome. CONCLUSIONS: Our results suggest that hypothermia is cardio protective after HIE. The level of cTnI at 24h of age is a good prognostic marker for neuro-developmental outcome at 18-22 months in both normothermia and hypothermia infants.

Lactate dehydrogenase in hypothermia-treated newborn infants with hypoxic-ischaemic encephalopathy.

AIMS: We investigated whether plasma lactate dehydrogenase (LDH) predicts outcome in hypothermia (HT)-treated term infants with moderate/severe hypoxic-ischaemic encephalopathy (HIE) and additionally whether LDH differs between infants with evidence for acute and nonacute perinatal insults and postnatal collapse (PNC). METHODS: Data from HT-treated infants with HIE (n = 39) were analysed retrospectively. Adverse outcome was defined as a Mental and/or Psychomotor Developmental Index (Bayley Scales of Infant Development II), at 18 months <70. The likely timing of insult onset was assessed in infants with an LDH sample obtained within 6 h of birth or PNC (n = 20). RESULTS: LDH differed between the favourable/adverse outcome groups at the end of HT treatment (median (IQR) 1540 (1400-1950)U/L vs. 3555 (3003-8705)U/L, (p < 0.01)). All infants (n = 22) with LDH <2085U/L had a favourable outcome while 6 of 11 infants with LDH ≥ 2085U/L had an adverse outcome. LDH in those who died (n = 4) was higher than the favourable outcome group (5090 (2915-12222)U/L, (p < 0.01)) but sampled earlier. Early LDH differed significantly (p < 0.01) between infants with evidence for acute or nonacute insults or PNC. CONCLUSION: THESE results offer a biomarker, with high negative predictive value in the assessment of outcome in HT-treated term infants, needing prospective validation.

'Relaxers' damage hair: evidence from amino acid analysis.

BACKGROUND: 'Relaxers' are used by more than two thirds of African females to straighten hair, with easy grooming and increased length often cited as reasons. A recent study reported relaxed hair lengths much shorter than expected, suggesting increased fragility; the potential for scalp inflammation and scarring alopecia remains unclear. OBJECTIVE: To investigate the biochemical effects of 'relaxers' on hair. METHODS: With informed consent, included participants represented 3 groups: natural hair, asymptomatic relaxed hair, and symptomatic (brittle) relaxed hair. Biochemical analysis was performed by using a Biochrom 30 amino acid analyzer. Differences in amino acid levels were assessed using either Wilcoxon rank sum test or matched-pairs signed-rank test. RESULTS: There was a decrease in cystine, citrulline, and arginine; however, an increase in glutamine was found in all relaxed compared to natural hair. Cystine levels (milligram per gram amino acid nitrogen) were similar in natural proximal and distal hair: 14 mg/g (range, 4-15 mg/g) versus 14 mg/g (range, 12-15 mg/g); P = .139. In asymptomatic relaxed hair, cystine levels were higher in less frequently relaxed samples proximal to scalp: 7.5 mg/g (5.6-12) versus 3.3 mg/g (1.3-9.2); P = .005. Cystine levels in distal asymptomatic relaxed and symptomatic relaxed hair were similar to each other and to those in the genetic hair fragility disease trichothiodystrophy. LIMITATIONS: It was not possible to analyze lye and no-lye 'relaxers' separately. CONCLUSIONS: 'Relaxers' are associated with reduced cystine consistent with fragile damaged hair. A decrease in citrulline and glutamine has been associated with inflammation; prospective studies are needed to investigate whether or how 'relaxers' induce inflammation.

Serum gentamicin concentrations in encephalopathic infants are not affected by therapeutic hypothermia.

OBJECTIVE: Mild hypothermia for 72 hours is neuroprotective in newborns with moderate or severe hypoxic-ischemic encephalopathy. A core temperature of 33.5 degrees C might reduce drug clearance leading to potential toxicity. Gentamicin is nephrotoxic and ototoxic at high serum concentrations. No study has investigated the influence of 72 hours of hypothermia on serum gentamicin concentrations (SGCs) in children of any age. We aimed to compare the SGCs in encephalopathic infants who underwent intensive care with therapeutic hypothermia or normothermia. METHODS: Data were collected retrospectively from 2 NICUs in Bristol, United Kingdom, that offered cooling therapy within clinical trials since 1998. Eligible infants (n = 55) developed grade 2/3 encephalopathy after birth and fulfilled the entry criteria defined in the CoolCap trial. Encephalopathic infants with similar demographic values were either nursed under normothermia or 72 h-hypothermia. Once-daily gentamicin dosage (4-5 mg/kg) was administered, and trough SGC was recorded with corresponding creatinine concentrations. The time and number of omitted drug doses were noted. RESULTS: Mean trough SGC (pre-second dose) and mean plasma creatinine concentrations for both treatment groups were similar (gentamicin: 2.19 +/- 1.7 [hypothermia] and 2.30 +/- 2.0 [normothermia] mg/L; creatinine: 115.6 +/- 42.8 [hypothermia] and 121.0 +/- 45.1 [normothermia] mumol/L). Forty percent of the trough SGCs in both groups were above the recommended trough concentration of 2.0 mg/L. A significant correlation (r(2) = 0.36) was found between high SGCs and impaired renal function assessed by raised plasma creatinine levels regardless of treatment options. CONCLUSIONS: Our data confirm that impaired renal function is strongly associated with high SGCs. Reduced body temperatures do not affect the clearance of gentamicin.

Cardiolipin and monolysocardiolipin analysis in fibroblasts, lymphocytes, and tissues using high-performance liquid chromatography-mass spectrometry as a diagnostic test for Barth syndrome.

Barth syndrome (BTHS) is an X-linked recessive disorder caused by mutations in the tafazzin (or TAZ) gene and is clinically characterized by (cardio)myopathy, neutropenia, and growth abnormalities. Biochemical abnormalities include decreased levels of the mitochondrial phospholipid cardiolipin, increased levels of monolysocardiolipin, and a lower degree of unsaturation of the (monolyso)cardiolipin acyl chains. Diagnostic testing for BTHS is routinely performed by TAZ gene sequencing, and recently a BTHS screening method in bloodspots has been developed, but both methods have important limitations. Because a validated confirmatory method is not yet available, we set up and validated a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method for BTHS in cultured fibroblasts, lymphocytes, and skeletal muscle based on cardiolipin, monolysocardiolipin, and the monolysocardiolipin/cardiolipin ratio. In addition, we performed retrospective analysis of 121 muscle samples of patients with myopathy of which mitochondrial origin was presumed, and we identified one patient with cardiolipin abnormalities similar to BTHS patients. Molecular analysis revealed a bona fide mutation in the TAZ gene. We conclude that (monolyso)cardiolipin analysis by HPLC-MS not only is a powerful tool to diagnose patients with clinical signs and symptoms of BTHS but also should be used in patients suffering from mitochondrial myopathies with unknown etiology.

Liver enzymes cannot be used to predict liver damage after global hypoxia-ischemia in a neonatal pig model.

BACKGROUND: The term newborn pig is an established model for studying both brain and organ pathology after hypoxia-ischemia (HI). Serial liver enzyme activity is often used to predict liver injury but little is known about the relation between consecutive values of different liver enzymes and histologically verified liver injury. OBJECTIVE: To determine whether plasma values of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) differed between newborn pigs with liver injures and pigs with normal livers after a severe global HI insult. METHODS: Nineteen < or =36-hour-old pigs underwent a 45-min global HI insult followed by 72-hour survival. Four histological sections from standardized areas within each liver were examined. Areas under the curve (AUC) for the enzymes were calculated and compared between pigs with pathological changes in the liver (n = 12) and pigs with normal liver histology (n = 7). RESULTS: No differences in AUC for the enzyme values were seen between the groups. However, in pigs with liver injuries a transient significant increase in LDH at the end of the HI insult (928 U/l (567-1,031)) was seen compared to the baseline value (679 U/l (548-866), p = 0.010). Significantly more liver injury was seen in animals with the umbilical vein catheter (UVC) tip inserted into the liver (p = 0.040) compared to animals with the UVC tip located outside the liver. CONCLUSIONS: In newborn pigs subjected to global HI, only LDH increases alongside pathological changes in the liver. Normal values of ALT and AST do not exclude hepatic injury.

Delayed hypothermia as selective head cooling or whole body cooling does not protect brain or body in newborn pig subjected to hypoxia-ischemia.

The neuroprotective efficacy of hypothermia (HT) after hypoxia-ischemia (HI) falls dramatically the longer the delay in initiating HT. Knowledge is scarce regarding protective or adverse effects of HT in organs beyond the brain. In addition, the relative effectiveness of selective head cooling (SHC) and whole body cooling (WBC) has not been studied. We aimed to examine whether 24 h HT, initiated 3 h after global HI is brain- and/or organ-protective using pathology, neurology, and biochemical markers. Fifty,

Xenon/hypothermia neuroprotection regimes in spontaneously breathing neonatal rats after hypoxic-ischemic insult: the respiratory and sedative effects.

BACKGROUND: Hypothermia (HT) reduces neuronal injury after perinatal asphyxia. The anesthetic gas xenon (XE) may enhance this effect. We investigated the sedative and respiratory effects of variable XE concentrations at 37 degrees C normothermia (NT) or 32 degrees C HT after a hypoxic-ischemic (HI) insult to determine the concentration at which XE was a respiratory depressant in spontaneously breathing 7-day-old rat pups. METHODS: (I) In three control groups, the effects of fasting at NT and HT were investigated. (II) Six groups were subjected to a HI insult (left carotid ligation then 90 min breathing 8% oxygen); three then breathed Air, 50%Xe or 70%Xe for 5 h at NT (NT(Air), NT(50%Xe), NT(70%Xe)), while three breathed identical mixtures during HT (HT(Air), HT(50%Xe), or HT(70%Xe)), in addition to a control group. Blood gases, glucose, and lactate were measured. Sedation (spontaneous movement/respiratory rate) was recorded. RESULTS: Blood chemistry data were successfully obtained from 70 pups. (I) Pups maintained normal blood gas, glucose, and lactate values after 9 h fasting at NT or HT. (II) After HI insult, in comparison with control and NT(Air) groups, 70%Xe at both NT and HT produced higher PCO2 and lower pH values while the HT(Air) and HT(50%Xe) groups only had lower pH values. The HT(70%Xe) combination produced the highest PCO2 and lowest pH values (56.8 mm Hg, 7.35, respectively) and the greatest sedative effect. CONCLUSION: After HI insult, 70%Xe at both NT and HT induced sedation, respiratory depression, CO2 retention, and a decrease in pH relative to air and control groups. The effects were largely avoided with 50%Xe.

Bloodspot assay using HPLC-tandem mass spectrometry for detection of Barth syndrome.

BACKGROUND: Barth syndrome (BTHS) is a serious X-linked, metabolic, multisystem disorder characterized by cardiomyopathy, neutropenia, myopathy, and growth delay. Because early diagnosis and appropriate treatment are of key importance for the survival of affected boys, we developed a biochemical BTHS screening method based on analysis of the monolysocardiolipin:cardiolipin ratio in bloodspots. METHODS: We performed chloroform/methanol extraction on quarter-inch punches of dried bloodspots on Guthrie cards from BTHS patients and controls. Extracts were dried (60 degrees C, N(2)) and reconstituted in CHCl(3)/methanol/H(2)O [50:45:5 vol/vol/vol, 0.1% NH(3) (25%)]. HPLC-tandem mass spectrometry analysis was performed with a normal-phase HPLC column and multiple reaction monitoring transitions for monolysocardiolipin (MLCL) and cardiolipin (CL) with a total run time of 10 min. The ratio of MLCL and CL was used as screening parameter. RESULTS: All BTHS patients (n = 31) had monolysocardiolipin:cardiolipin ratios >0.40 and all controls (n = 215) had monolysocardiolipin:cardiolipin ratios <0.23. Using a cutoff point of 0.30, a blind test of 206 samples (199 controls, 7 BTHS) had sensitivity and specificity of 100%. Bloodspots could be stored at 4 degrees C or room temperature for >1 year without affecting the test outcome. Three neonatal Guthrie cards of BTHS patients taken 3.6 to 5.8 years previously were correctly identified as positive for BTHS. CONCLUSIONS: HPLC-tandem mass spectrometry analysis of dried bloodspots is an unambiguous screening test for BTHS with potential for rapid screening of neonates suspected of having BTHS, making remote and retrospective diagnosis accessible for a disease that is almost certainly underdiagnosed.

Minicolumnar abnormalities in autism.

Autism is characterized by qualitative abnormalities in behavior and higher order cognitive functions. Minicolumnar irregularities observed in autism provide a neurologically sound localization to observed clinical and anatomical abnormalities. This study corroborates the initial reports of a minicolumnopathy in autism within an independent sample. The patient population consisted of six age-matched pairs of patients (DSM-IV-TR and ADI-R diagnosed) and controls. Digital micrographs were taken from cortical areas S1, 4, 9, and 17. The image analysis produced estimates of minicolumnar width (CW), mean interneuronal distance, variability in CW (V (CW)), cross section of Nissl-stained somata, boundary length of stained somata per unit area, and the planar convexity. On average CW was 27.2 microm in controls and 25.7 microm in autistic patients (P = 0.0234). Mean neuron and nucleolar cross sections were found to be smaller in autistic cases compared to controls, while neuron density in autism exceeded the comparison group by 23%. Analysis of inter- and intracluster distances of a Delaunay triangulation suggests that the increased cell density is the result of a greater number of minicolumns, otherwise the number of cells per minicolumns appears normal. A reduction in both somatic and nucleolar cross sections could reflect a bias towards shorter connecting fibers, which favors local computation at the expense of inter-areal and callosal connectivity.