MR lung perfusion measurements in adolescents after congenital diaphragmatic hernia: correlation with spirometric lung function tests.

OBJECTIVES: To evaluate whether lung perfusion continues to be reduced in 10-year-old children after congenital diaphragmatic hernia (CDH) and whether lung perfusion values correlate with spirometric lung function measurements. METHODS: Fifty-four patients after CDH repair received dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI)-based lung perfusion measurements at the age of 10 years (10.2 ± 1.0 years). Additionally, a control group of 10 children has been examined according to the same protocol. Lung spirometry was additionally available in 43 patients of the CDH group. A comparison of ipsilateral and contralateral parameters was performed. RESULTS: Pulmonary blood flow (PBF) was reduced on the ipsilateral side in CDH patients (60.4 ± 23.8 vs. 93.3 ± 16.09 mL/100 mL/min; p < 0.0001). In comparison to the control group, especially the ratio of ipsilateral to contralateral, PBF was reduced in CDH patients (0.669 ± 0.152 vs. 0.975 ± 0.091; p < 0.0001). There is a positive correlation between ipsilateral pulmonary blood flow, and spirometric forced 1-s volume (r = 0.45; p = 0.0024). CONCLUSIONS: Pulmonary blood flow impairment persists during childhood and correlates with spirometric measurements. Without the need for ionizing radiation, MRI measurements seem promising as follow-up parameters after CDH. KEY POINTS: • Ten-year-old children after congenital diaphragmatic hernia continue to show reduced perfusion of ipsilateral lung. • Lung perfusion values correlate with lung function tests after congenital diaphragmatic hernia.

Impact of cryopreservation on viability, gene expression and function of enteric nervous system derived neurospheres.

Introduction: Impairment of both the central and peripheral nervous system is a major cause of mortality and disability. It varies from an affection of the brain to various types of enteric dysganglionosis. Congenital enteric dysganglionosis is characterized by the local absence of intrinsic innervation due to deficits in either migration, proliferation or differentiation of neural stem cells. Despite surgery, children's quality of life is reduced. Neural stem cell transplantation seems a promising therapeutic approach, requiring huge amounts of cells and multiple approaches to fully colonize the diseased areas completely. A combination of successful expansion and storage of neural stem cells is needed until a sufficient amount of cells is generated. This must be combined with suitable cell transplantation strategies, that cover all the area affected. Cryopreservation provides the possibility to store cells for long time, unfortunately with side effects, i.e., upon vitality. Methods: In this study we investigate the impact of different freezing and thawing protocols (M1-M4) upon enteric neural stem cell survival, protein and gene expression, and cell function. Results: Freezing enteric nervous system derived neurospheres (ENSdN) following slow-freezing protocols (M1-3) resulted in higher survival rates than flash-freezing (M4). RNA expression profiles were least affected by freezing protocols M1/2, whereas the protein expression of ENSdN remained unchanged after treatment with protocol M1 only. Cells treated with the most promising freezing protocol (M1, slow freezing in fetal calf serum plus 10% DMSO) were subsequently investigated using single-cell calcium imaging. Freezing of ENSdN did not alter the increase in intracellular calcium in response to a specific set of stimuli. Single cells could be assigned to functional subgroups according to response patterns and a significant shift towards cells responding to nicotine was observed after freezing. Discussion: The results demonstrate that cryopreservation of ENSdN is possible with reduced viability, only slight changes in protein/gene expression patterns and without an impact on the neuronal function of different enteric nervous system cell subtypes, with the exception of a subtle upregulation of cells expressing nicotinergic acetylcholine receptors. In summary, cryopreservation presents a good method to store sufficient amounts of enteric neural stem cells without neuronal impairment, in order to enable subsequent transplantation of cells into compromised tissues.

Application of bacterial nanocellulose-based wound dressings in the management of thermal injuries: Experience in 92 children.

BACKGROUND: Management of pediatric thermal injuries involves a high standard of care in a multidisciplinary setting. To avoid physical and psychological sequelae, wound dressings should minimize hospitalization time and anesthesia while maximizing patient comfort. PATIENTS AND METHODS: 190 children with thermal injuries of the torso, arms and legs were treated with polyurethane foam dressings or bacterial nanocellulose sheets. Data were analyzed retrospectively regarding hospitalization, procedures with general anesthesia, scar formation, rate of infection and need for skin grafting. RESULTS: The groups did not differ significantly concerning age, gender distribution or percentage of injured total body surface area. Statistical analysis showed that length of hospitalized care and procedures undergoing anesthesia were significantly reduced in the nanocellulose group (each p < 0.0001). There was no significant difference in rate of complications, wound healing and rate of skin grafting between the two subgroups. DISCUSSION: Acting as a temporary epidermal substitute, bacterial nanocellulose enables undisturbed reepithelialization without further wound dressing changes. In children, no additional topical antimicrobial agents are indicated for unimpaired wound healing. CONCLUSIONS: Bacterial nanocellulose is superior to polyurethane foam regarding length of hospitalization and number of interventions under anesthesia. It offers a safe, cost-effective treatment option and provides excellent comfort in pediatric patients.

Acetylsalicylic acid enhances tachyphylaxis of repetitive capsaicin responses in TRPV1-GFP expressing HEK293 cells.

Since many years acetylsalicylic acid (ASA) is known for its antithrombotic, antiphlogistic and analgesic effects caused by irreversible acetylation of cyclooxygenase. ASA also inhibits capsaicin- and heat-induced responses in cultured dorsal root ganglia (DRG) neurons, suggesting TRPV1 (transient receptor potential channel of the vanilloid receptor family, subtype 1) to be an additional target of ASA. We now studied the effect of ASA on heterologously expressed rat TRPV1 using calcium microfluorimetry. Capsaicin dose-dependently increased intracellular calcium with an EC50 of 0.29 µM in rTRPV1 expressing HEK293 cells. During repetitive stimulation the second response to capsaicin was reduced (53.4 ± 8.3% compared to vehicle control; p<0.005; Student's unpaired t-test) by 1µM ASA, a concentration much below the one needed to inhibit cyclooxygenase (IC50 of 35 µM in thromboxane B2 production assay). In contrast, calcium transients induced by a single stimulus of 0.3 or 1 µM capsaicin were not significantly reduced by 0.3 or 1 µM ASA. These data suggest that ASA increases the tachyphylaxis of rTRPV1 channel activation. Mechanisms are unknown and may be direct by e.g. stabilization of the desensitized state or indirect via inhibition of intracellular signaling pathways e.g. of the mitogen-activated protein kinase family (MAPK/ERK).