Transcutaneous bilirubin measurement in preterm infants]

Transcutaneous bilirubinometry is an effective screening tool for neonatal jaundice in full-term babies. But its accuracy is not shown yet in preterm infants. METHODOLOGY: We carried out a prospective study in a neonatal intensive care unit. The study included 47 preterm infants. From birth, a transcutaneous bilirubin measurement (BTc) using the BiliCheck was made on the forehead of each newborn every 8 h. Blood sampling for determination of total serum bilirubin (BS) was combined with BTc: 1) if value of BTc was higher than limits values for phototherapy; 2) on the second day of life and 3) 4 hours after cessation of phototherapy. RESULTS: Mean gestational age was 30 week and mean birth weight was 1419 g. We studied 151 pairs of BTc and BS. Mean values obtained by BTc and BS were respectively 160.6+/-50 mumol/L and 190.6+/-61.4 mumol/L. A significant correlation between BTc and BS was found. But the limits of agreement were very wide. The negative predictive value (NPV) of BTc was above 90% in each group of gestational age. DISCUSSION: The need for phototherapy cannot be determined by BTc in preterm infants. But the BTc is reliable when its value is under the limits for phototherapy. CONCLUSION: With a very high incidence of neonatal jaundice (87%) in our cohort, a value of BTc under the limits for phototherapy has a good NPV in preterm infants.     

Cox proportional hazards survival regression in haplotype-based association analysis using the Stochastic-EM algorithm

It is now widely recognized that haplotype information inferred from genotypes can be of great interest to better characterize the role of a candidate gene in the etiology of a complex trait in the context of association studies. Several works have recently advocated the simultaneous estimation of haplotype frequencies and haplotype effects in order to get a better efficiency in parameter estimation. Most of the available models can deal with a binary or a quantitative phenotype, but none has yet discussed the application of haplotype-based association analysis to a survival outcome. We describe how the recently proposed Stochastic-EM (SEM) algorithm can be applied to estimate haplotype effects in censored data analysis using a standard Cox proportional hazards formulation. This model has been implemented in the THESIAS software freely available at http://www.genecanvas.org.     

Deciphering the molecular basis of venous thromboembolism: where are we and where should we go?

Venous thromboembolism (VTE) is a frequent disease that has a major genetic component of risk. However, known identified genetic risk factors account for <30% of idiopathic (without any environmental origin) VTE cases. This article aims to review the lessons learnt during recent decades in the field of the genetics of VTE, describe the present state‐of‐art methods and discuss promising themes for finding new susceptibility loci.     

The allergic risk of transgenic foods strategy for prevention

A significant number of allergens arise from foods. The allergic risk of transgenic foods must be evaluated in accordance with the recommendations of the Joint Expert Committee FAO/WHO. Potential issues are the risk of cross reactivity with existing allergens, the modification of allergenicity of the transgenic protein induced by a modified metabolism in the host, the modified allergenicity of the proteins of the transgenic plant, a potential neo-allergenicity of the transgenic protein, and the risk of dissemination through pollens, inducing a respiratory sensitization then a cross food allergy. The algorithm includes three steps for evaluation: first the search for significant homology of the protein with allergens listed in allergen databanks, or the identity of a sequence of six aminoacids with known epitopes, then a cross reactivity explored through the binding to IgEs from patients allergic to the source of the gene, or allergic to organisms of the same group or botanical family, and finally the extent of the pepsine resistance. The risk of immunogenicity has to be studied with appropriate animal models. A post-marketing surveillance is recommended for monitoring of adverse effects. The structure of an Allergo-Vigilance Network, the tools for efficiency and the groups at higher risk will be discussed. The potential risk of transgenic foods to be allergenic cannot be overlooked, not ignoring the fact that current technologies modify allergenicity of foods.     

Contrast enhanced ultrasound eases interpretation of an unclear renal tumor in addition to CT, MRI and histological findings--a case report in a young patient

Renal cancer represents accounts for approximately 3% of all adult malignancies with a rising incidence. Incidental diagnosis is mostly based upon ultrasound (US). US and Computed tomography (CT) are the standard imaging modalities for detecting renal cell cancer (RCC). Differentiation between malignant and benign renal tumors is of utmost importance. Contrast enhanced ultrasound (CUS) seems to be a promising new diagnostic option for diagnosis and preoperative treatment planning for patients with renal cancer. It is an additional examination to baseline ultrasound and CT. We report a case of a 37-year-old woman with a papillary renal cell cancer in which CUS helped to differentiate dignity of the tumor. CUS is an additional examination to baseline ultrasound and CT. It is a less invasive technique than contrast enhanced CT and shows even slight tumor blood flow. In addition it may allow a more rapid diagnosis, because of its bedside availability.     

B-flow and B-flow with 3D and SRI postprocessing before intervention and monitoring after stenting of the internal carotid artery

OBJECTIVE: To investigate the extent to which B-flow and B-flow with 3D postprocessing and speckle reduction imaging (SRI) have advantages in appraising the morphology of a high-grade stenosis of the internal carotid artery (ICA) for preinterventional planning and for postinterventional ultrasonographic follow-up. MATERIALS/METHODS: A comparative appraisal of flow with CCDS, power Doppler, B-flow and 3D B-Flow with SRI were carried out prospectively in 50 patients with >70% stenosis according to NASCET criteria in contrast medium-enhanced MRA before and after the intervention. After stenting of the internal carotid artery (ICA), i.a. digital substraction angiography (DSA) served as an additional reference method. RESULTS: In >70% ICA stenosis, simultaneous imaging of the pre-stenotic, intra-stenotic and post-stenotic flow was attained with B-flow in 45/90 cases (90%), with power Doppler in 39/50 cases (78%) and with CCDS in only 31/50 cases (62%). After intervention, a complete detection of flow without overwriting or blooming artifacts was achieved in all 50 patients only by B-flow. The intrastenotic flow (p<0.05) could be better demarcated against the lumen and the vessel wall before the intervention, whereas the flow within the stent could be very much better appraised after the intervention (p<0.01) using 3D postprocessing of B-flow with additional SRI. Re-stenoses with hypoechoic vascular wall changes (3/50 patients) were detected at an early stage using B-flow. CONCLUSIONS: B-flow technique with SRI and 3D postprocessing can facilitate the intrastenotic detection of flow in >70% ICA stenosis with fewer flow artifacts. After stenting, the perfused vascular lumen shows less flow artifacts compared with CCDS and power Doppler. In order to elucidate hemodynamic changes, additional Doppler examinations are still necessary.     

Cervical artery dissection: improved diagnosis by B-Flow ultrasound

OBJECTIVE: The objective of this study was to evaluate the efficiency of B-Flow ultrasound in diagnosing supraaortic vessel dissections compared with other ultrasound techniques including B scan, Color-Coded Doppler (CCDS) and Power Doppler (PD). MATERIALS AND METHODS: Eighty-eight patients with suspected arterial dissection of the neck vessels were included in this prospective trial. All patients were examined using B scan, Color-Coded Doppler sonography and Power Doppler. After documentation of the diagnoses, the patients were additionally examined by B-Flow ultrasound. Contrast-enhanced magnetic resonance angiography (MRA) was used as reference standard in all cases. RESULTS: Dissections of the carotid artery (n=19) and of the vertebral artery (n=35) were found in 44 patients. B-Flow imaging identified 52 of 54 arterial dissections that were confirmed by MRA. There were no false-positive diagnoses in ultrasound examination. The sensitivity of ultrasound examination using B scan, CCDS and PD in detecting all dissections was 95.9% and 99.1% with additional B-Flow examination. Sensitivity using B-Flow increased from 98.3% to 100% for carotid dissections and from 93.3% to 94.3% for vertebral artery dissections. Due to the lack of overwriting artifacts, B-Flow imaging detected residual flow within the false lumen more precisely. The reduced effect of the ultrasound probe angle facilitated imaging of fissures, membranes and low flow phenomena and improved the identification of low-reflection wall structures. The cine mode of the B-Flow showed undulating membrane movement most clearly. Contrast-enhanced MRA in conjunction with axial T1 and T2 weighted sequences enabled the best visualization of intramural hematomas. CONCLUSION: B-Flow imaging can significantly increase the sensitivity of ultrasound examination for dissections of the neck vessels. It also improves the visualization of flow within the true and false lumen, of hypoechoic thrombi and of intramural hematoma.