C1 Esterase Inhibitor Reduces BBB Leakage and Apoptosis in the Hypoxic Developing Mouse Brain.

Inflammatory pathways involved in blood-brain barrier (BBB) vulnerability and hypoxic brain oedema in models of perinatal brain injury seem to provide putative therapeutic targets. To investigate impacts of C1-esterase inhibitor (C1-INH; 7.5-30 IU/kg, i.p.) on functional BBB properties in the hypoxic developing mouse brain (P7; 8% O2 for 6 h), expression of pro-apoptotic genes (BNIP3, DUSP1), inflammatory markers (IL-1ß, TNF-alpha, IL-6, MMP), and tight junction proteins (ZO-1, occludin, claudin-1, -5), and S100b protein concentrations were analysed after a regeneration period of 24 h. Apoptotic cell death was quantified by CC3 immunohistochemistry and TUNEL staining. In addition to increased apoptosis in the parietal cortex, hippocampus, and subventricular zone, hypoxia significantly enhanced the brain-to-plasma albumin ratio, the cerebral S100b protein levels, BNIP3 and DUSP1 mRNA concentrations as well as mRNA expression of pro-inflammatory cytokines (IL-1ß, TNF-alpha). In response to C1-INH, albumin ratio and S100b concentrations were similar to those of controls. However, the mRNA expression of BNIP3 and DUSP1 and pro-inflammatory cytokines as well as the degree of apoptosis were significantly decreased compared to non-treated controls. In addition, occludin mRNA levels were elevated in response to C1-INH (p < 0.01). Here, we demonstrate for the first time that C1-INH significantly decreased hypoxia-induced BBB leakage and apoptosis in the developing mouse brain, indicating its significance as a promising target for neuroprotective therapy.

Influence of factor XIII activity on post-operative transfusion in congenital cardiac surgery-A retrospective analysis.

OBJECTIVES: Coagulation factor XIII (FXIII) plays a key role in fibrin clot stabilization-an essential process for wound healing following cardiothoracic surgery. However, FXIII deficiency as a risk for post-operative bleeding in pediatric cardiac surgery involving cardiopulmonary bypass (CPB) for congenital heart disease (CHD) is controversially discussed. Thus, as primary outcome measures, we analyzed the association of pre-operative FXIII activity and post-operative chest tube drainage (CTD) loss with transfusion requirements post-operatively. Secondary outcomes included the influence of cyanosis and sex on transfusion. METHODS: Our retrospective analysis (2009-2010) encompassed a single center series of 76 cardio-surgical cases with CPB (0-17 years, mean age 5.61 years) that were post-operatively admitted to our pediatric intensive care unit (PICU). The observational period was 48 hours after cardiac surgery. Blood cell counts and coagulation status, including FXIII activity were routinely performed pre- and post-operatively. The administered amount of blood products and volume expanders was recorded electronically, along with the amount of CTD loss. Uni- and multivariate logistic regression analysis was performed to calculate the associations (odds ratios) of variables with post-operative transfusion needs. RESULTS: FXIII activities remained stable following CPB surgery. There was no association of pre- and post-operative FXIII activities and transfusion of blood products or volume expanders in the first 48 hours after surgery. Similarly, FXIII showed no association with CTD loss. Cyanosis and female sex were associated with transfusion rates. CONCLUSIONS: Although essentially involved in wound healing and clotting after surgery, FXIII activity does not serve as a valid predictor of post-operative transfusion need.

Influence of PCO2 Control on Clinical and Neurodevelopmental Outcomes of Extremely Low Birth Weight Infants.

BACKGROUND: Levels or fluctuations in the partial pressure of CO2 (PCO2) may affect outcomes for extremely low birth weight infants. OBJECTIVES: In an exploratory analysis of a randomized trial, we hypothesized that the PCO2 values achieved could be related to significant outcomes. METHODS: On each treatment day, infants were divided into 4 groups: relative hypocapnia, normocapnia, hypercapnia, or fluctuating PCO2. Ultimate assignment to a group for the purpose of this analysis was made according to the group in which an infant spent the most days. Statistical analyses were performed with analysis of variance (ANOVA), the Kruskal-Wallis test, the χ2 test, and the Fisher exact test as well as by multiple logistic regression. RESULTS: Of the 359 infants, 57 were classified as hypocapnic, 230 as normocapnic, 70 as hypercapnic, and 2 as fluctuating PCO2. Hypercapnic infants had a higher average product of mean airway pressure and fraction of inspired oxygen (MAP × FiO2). For this group, mortality was higher, as was the likelihood of having moderate/severe bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), and poorer neurodevelopment. Multiple logistic regression analyses showed an increased risk for BPD or death associated with birth weight (p < 0.001) and MAP × FiO2 (p < 0.01). The incidence of adverse neurodevelopment was associated with birth weight (p < 0.001) and intraventricular hemorrhage (IVH; p < 0.01). CONCLUSIONS: Birth weight and respiratory morbidity, as measured by MAP × FiO2, were the most predictive of death or BPD and NEC, whereas poor neurodevelopmental outcome was associated with low birth weight and IVH. Univariate models also identified PCO2. Thus, hypercapnia seems to reflect greater disease severity, a likely contributor to differences in outcomes.

Neurodevelopmental outcomes of extremely low birthweight infants randomised to different PCO2 targets: the PHELBI follow-up study.

BACKGROUND: Tolerating higher partial pressures of carbon dioxide (PCO2) in mechanically ventilated extremely low birthweight infants to reduce ventilator-induced lung injury may have long-term neurodevelopmental side effects. This study analyses the results of neurodevelopmental follow-up of infants enrolled in a randomised multicentre trial. METHODS: Infants (n=359) between 400 and 1000 g birth weight and 23 0/7-28 6/7 weeks gestational age who required endotracheal intubation and mechanical ventilation within 24 hours of birth were randomly assigned to high PCO2 or to a control group with mildly elevated PCO2 targets. Neurodevelopmental follow-up examinations were available for 85% of enrolled infants using the Bayley Scales of Infant Development II, the Gross Motor Function Classification System (GMFCS) and the Child Development Inventory (CDI). RESULTS: There were no differences in body weight, length and head circumference between the two PCO2 target groups. Median Mental Developmental Index (MDI) values were 82 (60-96, high target) and 84 (58-96, p=0.79). Psychomotor Developmental Index (PDI) values were 84 (57-100) and 84 (65-96, p=0.73), respectively. Moreover, there was no difference in the number of infants with MDI or PDI <70 or <85 and the number of infants with a combined outcome of death or MDI<70 and death or PDI<70. No differences were found between results for GMFCS and CDI. The risk factors for MDI<70 or PDI<70 were intracranial haemorrhage, bronchopulmonary dysplasia, periventricular leukomalacia, necrotising enterocolitis and hydrocortisone treatment. CONCLUSIONS: A higher PCO2 target did not influence neurodevelopmental outcomes in mechanically ventilated extremely preterm infants. Adjusting PCO2 targets to optimise short-term outcomes is a safe option. TRIAL REGISTRATION NUMBER: ISRCTN56143743.

Permissive hypercapnia in extremely low birthweight infants (PHELBI): a randomised controlled multicentre trial.

BACKGROUND: Tolerating higher partial pressure of carbon dioxide (pCO2) in mechanically ventilated, extremely low birthweight infants might reduce ventilator-induced lung injury and bronchopulmonary dysplasia. We aimed to test the hypothesis that higher target ranges for pCO2 decrease the rate of bronchopulmonary dysplasia or death. METHODS: In this randomised multicentre trial, we recruited infants from 16 tertiary care perinatal centres in Germany with birthweight between 400 g and 1000 g and gestational age 23-28 weeks plus 6 days, who needed endotracheal intubation and mechanical ventilation within 24 h of birth. Infants were randomly assigned to either a high target or control group. The high target group aimed at pCO2 values of 55-65 mm Hg on postnatal days 1-3, 60-70 mm Hg on days 4-6, and 65-75 mm Hg on days 7-14, and the control target at pCO2 40-50 mmHg on days 1-3, 45-55 mm Hg on days 4-6, and 50-60 mm Hg on days 7-14. The primary outcome was death or moderate to severe bronchopulmonary dysplasia, defined as need for mechanical pressure support or supplemental oxygen at 36 weeks postmenstrual age. Cranial ultrasonograms were assessed centrally by a masked paediatric radiologist. This trial is registered with the ISRCTN registry, number ISRCTN56143743. RESULTS: Between March 1, 2008, and July 31, 2012, we recruited 362 patients of whom three dropped out, leaving 179 patients in the high target and 180 in the control group. The trial was stopped after an interim analysis (n=359). The rate of bronchopulmonary dysplasia or death in the high target group (65/179 [36%]) did not differ significantly from the control group (54/180 [30%]; p=0·18). Mortality was 25 (14%) in the high target group and 19 (11%; p=0·32) in the control group, grade 3-4 intraventricular haemorrhage was 26 (15%) and 21 (12%; p=0·30), and the rate of severe retinopathy recorded was 20 (11%) and 26 (14%; p=0·36). INTERPRETATION: Targeting a higher pCO2 did not decrease the rate of bronchopulmonary dysplasia or death in ventilated preterm infants. The rates of mortality, intraventricular haemorrhage, and retinopathy did not differ between groups. These results suggest that higher pCO2 targets than in the slightly hypercapnic control group do not confer increased benefits such as lung protection. FUNDING: Deutsche Forschungsgemeinschaft.

Endothelial cells influence the sodium nitroprusside mediated inhibition of platelet aggregation by an as yet unkown pathway.

UNLABELLED: The clinical use of Sodium nitroprusside (SNP) may be associated with an alteration of platelet function. The main focus of this study was the effect of SNP on platelet aggregation in the absence or presence of endothelial cells. METHODS: Platelets were incubated with different concentrations of SNP with and without endothelial cells. Platelet aggregation was induced by ADP. RESULTS: Platelet aggregation was significantly inhibited by all concentrations of SNP. Endothelial cells significantly increased this inhibitory effect of SNP. Time course studies showed an inverse correlation of incubation time to platelet aggregation inhibition in the absence of endothelial cells, and a direct correlation in the presence of endothelial cells. Blocking platelet and endothelial cell guanylate cyclase with 1 H-(1,2,4)-oxadiazolo(4,3-a) quinoxalin-1-one (ODQ), or pretreatment of the endothelial cells with cyclooxygenase - inhibitors, had no influence on the increased inhibitory effect of the endothelial cells. Cyanide reversed the inhibitory effect of SNP completely. CONCLUSION: Endothelial cells play an important role in the SNP mediated inhibition of platelet aggregation. The effect is reversible only by cyanide, not by blocking classical NO signal transduction.

Improved closure of patent ductus arteriosus with high doses of ibuprofen.

The patent ductus arteriosus (PDA) is associated with various complications of prematurity. Cyclooxygenase-inhibitors are the first-line intervention for closure of the PDA. However, the rates of PDA closure still are unsatisfactory. Therefore, an individual trial was performed by changing the strategy for treating neonates with ibuprofen to induce the closure of PDA. In a retrospective study, patients receiving 20, 10, and 10 mg/kg bodyweight ibuprofen (group 1) were compared by chart review with those receiving 10, 5, 5 mg/kg (group 2). The rate of PDA closure, the incidence of side effects related to the use of ibuprofen, and the need for surgical intervention for closure of the PDA were analyzed. A higher rate of closure after three doses in group 1 could be observed (60.9 vs 52.6%; p = 0.75), which was not significant but indicated a clear positive trend. If closure of the PDA was unsuccessful, intravenous ibuprofen was continued for an additional 2 days. After 5 days, 91.3% of PDA in group 1 was closed compared with 68.4% PDA in group 2. In summary, only 8.7% of the group 1 neonates needed surgical closure of PDA after insufficient medicamentous closure compared with 31.6% in group 2 (p = 0.25). Although not statistically significant, a clear positive trend for using the higher-dose medication can be seen. More work dealing with the limitations of a retrospective study must be done. Based on the data from this study, high-dose ibuprofen seems able to increase the rate of effective medicamentous PDA closure without any further unwanted side effects.

Influence of gestational age, cesarean section, and type of feeding on fecal human beta-defensin 2 and tumor necrosis factor-alpha.

OBJECTIVE: : Development of the mucosal immune system is essential for controlling antigenic response. External factors are known to influence the immune system, such as breast-feeding or the mode of delivery. The aim of the present study was to investigate maturation of the enteric immune system. PATIENTS AND METHODS: : In stool samples of 59 preterm and term-born infants we measured the concentration of human beta-defensin 2 (HBD 2), an endogenous antimicrobial peptide, and tumor necrosis factor-alpha (TNF-alpha), a cytokine playing a central role in mucosal inflammation, by enzyme-linked immunosorbent assay. RESULTS: : Mode of delivery as well as nutrition (breast-feeding or formula) had no influence on the fecal concentration of HBD-2 or TNF-alpha, but there was a significant increase in the concentration of HBD-2 in correlation with gestational age. TNF-alpha showed no change in concentration. CONCLUSIONS: : Low fecal HBD-2 may be a risk factor in preterm infants to develop neonatal enteric disease, such as necrotizing enterocolitis.

Significance of salivary adrenomedullin in the maintenance of oral health: stimulation of oral cell proliferation and antibacterial properties.

Adrenomedullin (ADM) promotes epithelial cell proliferation and antimicrobial activity in the gastrointestinal tract. Since ADM is also present in saliva, it was the objective of our study to investigate the role of salivary ADM in the maintenance of oral health. We found mRNA for ADM and the specific receptors CRLR-RAMP2 and CRLR-RAMP3 expressed by the salivary glands and by oral keratinocytes. The hormone was detected in the glandular tissues by western blot, being slightly bigger than the synthetic peptide, indicating a posttranslational modification. ADM was localized using immunohistochemistry and immunofluorescence. Staining specific for ADM was observed near the cell nuclei of the salivary ducts and acini. There was no correlation between ADM from matched saliva and serum of healthy volunteers. The physiological role of salivary ADM in the oral cavity was investigated by incubating buccal keratinocytes with ADM and measurement of the cell proliferation using bromodeoxyuridine (BrDU) assays. There was a significant, dose dependent increase (up to 5-fold; p<0.001) of the BrDU incorporation after stimulation with ADM (1.5 to 50 ng/mL). The antibacterial properties of salivary ADM was studied by incubation of Gram+ and Gram- bacteria and yeast, isolated from human oral flora, with ADM (0.01-1000 ng/mL) for 24 h. Bacterial growth was inhibited dose dependently (p<0.001), whereas the yeast was not affected. This finding was consistent when using radial growth inhibition test on agarose plates as well as photometric measurement in microtiter plates. Our findings suggest an important role of salivary ADM in the maintenance of oral health, being involved as well as in oral cell proliferation and anti-bacterial defense.

Evaluation of saliva collection devices for the analysis of steroids, peptides and therapeutic drugs.

The recovery of steroids, peptides and therapeutic drugs from commercial saliva collection devices was investigated. Saliva, spiked with defined concentrations of the analytes was applied to the Quantisal, three different Salivettes, and the Saliva-Collection-System to investigate effects of volume, exposure time and temperature on the recovery. Additionally, saliva was collected from healthy subjects with the same devices. It was found that glucocorticoids can be measured very well from samples obtained with the synthetic fiber Salivettes and the Quantisal (80-100%). For androgens, the Quantisal and the Saliva-Collection-System reached recoveries >80%. The Quantisal and polyester Salivette achieved best recoveries (>80%) for peptides. The results for the cotton Salivette were extremely poor for melatonin, insulin or IL-8 (<20%). The results from the spike-recovery experiments were confirmed by samples collected from healthy volunteers. For most therapeutic drugs the synthetic fiber Salivettes achieved best recoveries of 100+/-10%. Longer exposure of saliva on the collection devices must be avoided for most of the analytes, due to their limited stability and increased adsorption. In conclusion, no device is suitable for all of the salivary compounds. Strict pre-analytical precautions must be considered (e.g. immediate processing of the sample) to guarantee reliable analytical results.

Magnetic resonance lung function--a breakthrough for lung imaging and functional assessment? A phantom study and clinical trial.

BACKGROUND: Chronic lung diseases are a major issue in public health. A serial pulmonary assessment using imaging techniques free of ionizing radiation and which provides early information on local function impairment would therefore be a considerably important development. Magnetic resonance imaging (MRI) is a powerful tool for the static and dynamic imaging of many organs. Its application in lung imaging however, has been limited due to the low water content of the lung and the artefacts evident at air-tissue interfaces. Many attempts have been made to visualize local ventilation using the inhalation of hyperpolarized gases or gadolinium aerosol responding to MRI. None of these methods are applicable for broad clinical use as they require specific equipment. METHODS: We have shown previously that low-field MRI can be used for static imaging of the lung. Here we show that mathematical processing of data derived from serial MRI scans during the respiratory cycle produces good quality images of local ventilation without any contrast agent. A phantom study and investigations in 85 patients were performed. RESULTS: The phantom study proved our theoretical considerations. In 99 patient investigations good correlation (r = 0.8; p < or = 0.001) was seen for pulmonary function tests and MR ventilation measurements. Small ventilation defects were visualized. CONCLUSION: With this method, ventilation defects can be diagnosed long before any imaging or pulmonary function test will indicate disease. This surprisingly simple approach could easily be incorporated in clinical routine and may be a breakthrough for lung imaging and functional assessment.

Endothelial cells play an important role in the antiaggregatory effect of nitric oxide.

OBJECTIVE: To investigate the role of endothelial cyclooxygenase in the antiaggregatory effect of nitric oxide, and to investigate the significance of the time span between contact of nitric oxide and platelets and laboratory evaluation by platelet aggregation. DESIGN: Prospective, controlled, in vitro study. SETTING: Research laboratory of a university hospital. PARTICIPANTS: Three healthy volunteers. INTERVENTIONS: Incubation of platelets with different concentrations (30 microM, 100 microM, 500 microM, 1000 microM) of the nitric oxide-donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) for varying incubation times (0 hrs, 1 hr, 2 hrs, 4 hrs) with and without endothelial cells. Induction of platelet aggregation with adenosine diphosphate. Inhibition of the effect of SNAP by 100 microM of the guanylate cyclase inhibitor 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ). Inhibition of prostacyclin production by endothelial cells with COX inhibitors acetyl salicylic acid (1 mM) and indomethacin (10 microM). MEASUREMENTS AND MAIN RESULTS: Incubation with endothelial cells (= controls) had no effect on platelet aggregation. Platelet aggregation was significantly inhibited by all concentrations of SNAP. Time course studies with 30 microM of SNAP showed an inhibitory effect only after 0, 1, and 2 hrs of incubation, whereas after 4 hrs of incubation the inhibition of platelet aggregation could not be detected any more. Endothelial cells significantly increased the inhibitory effect of SNAP after 1 and 2 hrs of incubation. Incubation with ODQ with and without endothelial cells reversed the SNAP-mediated inhibition of maximum platelet aggregation regardless of the incubation time. Pretreatment of the endothelial cells with the COX inhibitors acetyl salicylic acid and indomethacin blocked the increased inhibitory effect of the endothelial cells after 1 and 2 hrs of incubation. CONCLUSIONS: The time span between nitric oxide contact with platelets and induction of platelet aggregation by adenosine 5'-diphosphate is important for correct estimation of the antiaggregatory effect of nitric oxide. Endothelial cyclooxygenase plays an important role in the nitric oxide-mediated inhibition of platelet aggregation.