Evaluation of image quality and radiation dose of thoracic and coronary dual-source CT in 110 infants with congenital heart disease

Background:  There are only a few reports on the diagnostic accuracy, and the technical and clinical feasibility, of multidetector CT (MDCT) in infants with congenital heart disease (CHD). Objective:  To evaluate the image quality and radiation dose of DSCT in babies with CHD. Materials and methods:  From November 2006 to November 2007, 110 consecutive infants with CHD referred for pre- or postoperative CT evaluation were included. All these infants had a spiral angiothoracic DSCT scan after injection of 300 mg/ml iopromide at 0.5–1 ml/s with a power injector using a low-dose protocol (80 kVp and 10 mAs/kg). Of these infants, 34 also underwent an ECG-gated coronary CT scan for evaluation of the course of the coronary arteries. Results:  No serious adverse events were recorded. The mean dose-length product was 8±6 mGy.cm (effective dose 0.5±0.2 mSv) and 21±9 mGy.cm (effective dose 1.3±0.6 mSv) during the non-ECG-gated spiral acquisition and ECG-gated acquisition, respectively. Diagnostic quality images were achieved with the spiral acquisition in 89% of cases. Compared to the spiral mode, ECG-gated acquisition significantly improved the visualization of the coronary arteries, with a diagnostic rate of 91% and 84% for the left and right coronary arteries, respectively. Conclusion:  DSCT together with iopromide at 300 mg/ml is a valuable tool for the routine clinical evaluation of infants with CHD. ECG-gated acquisition provides reliable visualization of the course of the coronary arteries.     

Living donor liver transplantation in critically ill children

From December 1993, St Christopher's Hospital for Children, Philadelphia, PA, USA has provided living donors the opportunity to donate a portion of their liver to children who are critically ill. This report evaluates the results of living donor liver transplants (LDLT) in critically ill children. We retrospectively reviewed the first 22 LDLT at our institution and compared the patient and graft survival of the nine critically ill children with the 13 stable children. Twenty-two LDLT have been performed at our institution between December 1993 and October 1997. Nine of 22 transplants [United Network for Organ Sharing (UNOS) Status I] were performed in children who were critically ill. Thirteen of the LDLT (UNOS Status II and III) were performed on stable children either in the hospital or admitted electively from home. The median weight and age at the time of transplant were 7 kg (range 4.6-54.5 kg) and 16 months (range 3 months-12 yr), respectively, and there was no statistical difference between the two groups. In critically ill children the 1-yr allograft and patient survival was 66% and 89%, respectively, exceeding the published results from UNOS for patients on life support (59.5% graft and 69.7% patient survival at 1 yr). One-yr allograft and patient survival in the stable children was 92.3% and 100%, respectively. All living donors are alive and well with normal liver function. In conclusion, our results show that LDLT is a viable approach for transplantation in critically ill children with liver failure and should be offered to potential donors.     

CO2-fixing enzymes during moulting from third larval to fourth larval stage of Anisakis simplex and Hysterothylacium aduncum (Nematoda: Anisakidae)

The fixing of CO₂ is an important metabolic process for many organisms. In the anisakid nematodes, CO₂ has been shown to be necessary for their development, at least in vitro. The presence of CO₂ stimulates the moulting (M3) of the larvae from the third (L3) to the fourth (L4) stage and prolongs the survival, at least, in vitro. We determined the activity of CO₂-fixing enzymes, common to many organisms, in two anisakids: Anisakis simplex, a parasite of cetaceans, and Hysterothylacium aduncum, a parasite of fish. Although no activity was detected for pyruvate carboxylase or carboxylating-malic enzyme, we detected phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxylase (PEPC) activity. In A. simplex, PEPCK was clearly higher than that of PEPC throughout the moulting process studied. In H. aduncum, although the activity of both enzymes was of similar magnitude, they showed different behaviour; PEPCK activity decreased after the moulting to L4, PEPC activity increased so that the ratio PEPCK/PEPC activity decreased from 1.90 before moulting to 0.59 after.An erratum to this article can be found at     

Oxidative DNA damage induced by Ochratoxin A in the HK-2 human kidney cell line: evidence of the relationship with cytotoxicity

Ochratoxin A (OTA) is a mycotoxin produced by species of the genera Aspergillus and Penicillium. The kidneys are the target organ of this mycotoxin and it is considered a potent renal carcinogen in male rats. The mechanisms of its genotoxicity and carcinogenicity have been studied thoroughly, but controversial results have been published. The aim of this study was to evaluate the ability of OTA to produce single-strand DNA breaks and oxidative DNA damage in the human renal proximal tubular epithelial cell line (HK-2), due to the fact that there is no study on human kidney cells as the toxic target. In addition, we attempted to determine if biotransformation processes mediate OTA genotoxicity. Therefore, single-cell gel electrophoresis assay (comet assay) was performed after 3h- and 6h-treatments using different OTA concentrations, both cytotoxic and non-cytotoxic, in order to be able to distinguish a genotoxic effect of the mycotoxin from an indirect effect derived from its general cellular toxicity. No effect was shown where no cytotoxicity was found, both in the presence and in the absence of metabolic activation (10% rat liver S9-mix). However, oxidative DNA damage was shown at cytotoxic concentrations when formamidopyrimidine DNA glycosylase (FPG) and endonucleaseIII (EndoIII) were introduced in the assay with or without metabolic activation. Furthermore, at these concentrations, an elevation of reactive oxygen species was measured and pre-incubation with N-acetyl-L-cysteine was able to produce a slight protective effect on OTA-induced oxidative DNA damage as well as cytotoxicity. These data suggest that OTA is not acting as a direct genotoxic carcinogen and that oxidative stress is implicated in the genotoxicity and cytotoxicity observed in these human renal cells.     

Radiation dose for thoracic and coronary step-and-shoot CT using a 128-slice dual-source machine in infants and small children with congenital heart disease

Background  

For coronary artery visualization, retrospective ECG-gated acquisition by dual-source computed tomography (DSCT) was superior to spiral non-ECG-gated acquisition in a paediatric population of congenital heart disease (CHD) patients. However, retrospective cardiac CT is associated with substantial radiation doses to the patient. Recently, DSCT with end-systolic reconstruction was found to be robust for imaging the coronary arteries in patients with high heart rates.