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We report the case of an 11-month-old male infant with a complex congenital heart disease who was admitted in the intensive care unit following cardiorespiratory arrest at home. Toxicological urine screening reported an ethanol concentration of 0.65 g/L using an enzymatic assay, without suspicion of alcohol intake; a significant amount of ethanol concentration was found in two plasma samples using the same enzymatic assay. Plasma and urine ethanol concentrations were below the limit of quantification (LOQ) when tested using a gas chromatography method. Urine ethanol level was also below the LOQ when tested by enzymatic assay after an initial urine ultrafiltration. These results confirmed our suspicion of matrix interference due to elevated lactate and lactate dehydrogenase levels interfering in the enzymatic assay. This analytical interference, well-known in postmortem samples, extensively studied in vitro , has been rarely reported in vivo , especially in children. To the best of our knowledge, this case is only the sixth one reported in an infant's plasma and the first initially discovered from urine. Indeed, as for ethanol, this last matrix has not been studied in the context of this artifact that may induce false-positive ethanol results while seeking a diagnosis in life-threatening or fatal situations that are potentially subject to forensic scrutiny. In parallel to a synthetic literature review, we propose a simple, informative decision tree, in order to help health professionals suspecting a false-positive result when performing an ethanol assay. [ABSTRACT FROM AUTHOR]

F-actin structures and their distribution are important determinants of the dynamic shapes and functions of eukaryotic cells. Actin waves are F-actin formations that move along the ventral cell membrane driven by actin polymerization. Dictyostelium myosin IB is associated with actin waves but its role in the wave is unknown. Myosin IB is a monomeric, non-filamentous myosin with a globular head that binds to F-actin and has motor activity, and a non-helical tail comprising a basic region, a glycine-proline-glutamine-rich region and an SH3-domain. The basic region binds to acidic phospholipids in the plasma membrane through a short basic-hydrophobic site and the Gly-Pro-Gln region binds F-actin. In the current work we found that both the basic-hydrophobic site in the basic region and the Gly-Pro-Gln region of the tail are required for the association of myosin IB with actin waves. This is the first evidence that the Gly-Pro-Gln region is required for localization of myosin IB to a specific actin structure in situ. The head is not required for myosin IB association with actin waves but binding of the head to F-actin strengthens the association of myosin IB with waves and stabilizes waves. Neither the SH3-domain nor motor activity is required for association of myosin IB with actin waves. We conclude that myosin IB contributes to anchoring actin waves to the plasma membranes by binding of the basic-hydrophobic site to acidic phospholipids in the plasma membrane and binding of the Gly-Pro-Gln region to F-actin in the wave.

BackgroundWe investigated changes in the spatial distribution of schistosomiasis in Mali following a decade of donor-funded control and a further 12 years without control.Methodology/principal findingsNational pre-intervention cross-sectional schistosomiasis surveys were conducted in Mali in 1984-1989 (in communities) and again in 2004-2006 (in schools). Bayesian geostatistical models were built separately for each time period and on the datasets combined across time periods. In the former, data from one period were used to predict prevalence of schistosome infections for the other period, and in the latter, the models were used to determine whether spatial autocorrelation and covariate effects were consistent across periods. Schistosoma haematobium prevalence was 25.7% in 1984-1989 and 38.3% in 2004-2006; S. mansoni prevalence was 7.4% in 1984-1989 and 6.7% in 2004-2006 (note the models showed no significant difference in mean prevalence of either infection between time periods). Prevalence of both infections showed a focal spatial pattern and negative associations with distance from perennial waterbodies, which was consistent across time periods. Spatial models developed using 1984-1989 data were able to predict the distributions of both schistosome species in 2004-2006 (area under the receiver operating characteristic curve was typically >0.7) and vice versa.Conclusions/significanceA decade after the apparently successful conclusion of a donor-funded schistosomiasis control programme from 1982-1992, national prevalence of schistosomiasis had rebounded to pre-intervention levels. Clusters of schistosome infections occurred in generally the same areas accross time periods, although the precise locations varied. To achieve long-term control, it is essential to plan for sustainability of ongoing interventions, including stengthening endemic country health systems.

Introduction: Syphilis is a sexually transmitted disease caused due to bacterium Treponema pallidum. The prevalence of this infection decreased significantly by the use of penicillin, but it is observed that it reappears particularly in cases of congenital syphilis (CS). Objective: to describe the effects of neonatal CS in newborns (NB) in a public hospital in Niterói - RJ, from January 2005 to June 2006 and to observe the birth weight and serology of newborns with CS notification. The purpose of this study is also to describe the CS treatment in each case. Methods: a sample of 35 CS notifications was recorded from the Center for Hospital Surveillance at the Antonio Pedro University Hospital (HUAP), Niterói - RJ, from January 2005 to June 2006. Data from the notifications was used and home visit was done to collect blood samples. Results: the study population is comprised of 29 live birth patients, four miscarriages and two stillbirths. Only two cases (6.9%) had evidence of CS bone abnormalities. The VDRL test performed in cerebrospinal fluid (CSF) of the cases proved to be non-reactive for all patients. VDRL serum of newborns at birth was positive for 23 (79.31 %) patients. The crystalline penicillin G was administered in 26 (89.65 % cases,) procaine penicillin G in two (6.9%) and for one individual both crystalline penicillin G and procaine penicillin G was used. Conclusion: fetal death and abortion were the most ominous outcome and impact of CS. Long bones alterations were scarcely found in few samples. Low birth weight was observed in a few cases. CSF VDRL was not reactive in all cases. The use of several antibiotic regimens was in disagreement with the proposed protocol issued by the Ministry of Health.

Introdução: papilomavírus humano (HPV) é um vírus de DNA que pode infectar a pele e mucosas, com mais de 100 tipos diferentes descritos, sendo 45 deles considerados sexualmente transmissíveis. Objetivo: relatar o caso de condiloma acuminado extragenital, facilitado pela presença de intertrigo. Métodos: relato de caso de paciente com condiloma acuminado em região hipogástrica. Resultados: mulher atendida no ambulatório de DST/AIDS do setor de Ginecologia da Santa Casa de Misericórdia de Vitória, em 2007, com 46 anos de idade, apresentando lesão condilomatosa extensa associada à intertrigo em região hipogástrica, acima da cicatriz de Pfannestiel e pequenas lesões vulvares compatíveis, clinicamente, com condilomas. Feita a opção pela exérese cirúrgica em lesão de abdome, a qual evidenciou condiloma acuminado e cauterização química de lesões vulvares. Solicitados exames para doenças sexualmente transmissíveis, que foram normais, incluindo citologia oncótica, colposcopia e teste rápido para gonococo e clamídia. Conclusão: a umidade e o calor locais, provocados pelo abdome em avental, com concomitância de área de intertrigo, poderiam justificar a presença de condiloma acuminado nesta região.

Introdução: a sífilis congênita é uma das mais incabíveis causas de morbidez e mortalidade perinatal, o que revela uma assistência pré-natal ineficaz. A infecção intra-uterina pelo Treponema pallidum pode resultar em natimorto, morte neonatal, prematuro e/ou lesões sifilíticas que conduzem a desordens como surdez, prejuízo neurológico e deformidades ósseas. É infecção congênita que persiste em destaque, mesmo com a penicilina G benzatina reduzindo em quase 98% a transmissão materno-fetal quando a mãe é tratada adequadamente. Objetivo: neste trabalho apresenta-se o caso de uma gestação gemelar que teve como desfecho a morte intra-útero dos fetos, a retenção placentária e o choque hipovolêmico, culminando em histerectomia, ocorrido na maternidade do Hospital Escola Luiz Gioseffi Jannuzzi, em Valença, Rio de Janeiro. Relato do caso: relata-se a história de uma paciente de 33 anos, de classe socioeconômica baixa, multípara, admitida no serviço em trabalho de parto prematuro, com ambos os fetos mortos intra-útero. O parto foi transpélvico, com retenção placentária e choque hipovolêmico. Efetuado o pronto-atendimento, foi realizada a histerectomia e a estabilização do quadro. O VDRL, por razão da internação, revelou positividade, com início do tratamento. A paciente permaneceu internada oito dias. Conclusão: fica evidente que a sífilis é uma moléstia com graves conseqüências para as gestantes e seus conceptos, visto que 80% das mães infetadas sem tratamento, transmitem a doença para os fetos e um grande número destes morre antes de alcançar dois anos de idade

HIV-1 Tat is a key viral protein that stimulates several steps of viral gene expression. Tat is especially required for the transcription of viral genes. Nevertheless, it is still not clear if and how Tat is incorporated into HIV-1 virions. Cyclophilin A (CypA) is a prolyl isomerase that binds to HIV-1 capsid protein (CA) and is thereby encapsidated at the level of 200 to 250 copies of CypA/virion. Here, we found that a Tat-CypA-CA tripartite complex assembles in HIV-1-infected cells and allows Tat encapsidation into HIV virions (1 Tat/1 CypA). Biochemical and biophysical studies showed that high-affinity interactions drive the assembly of the Tat-CypA-CA complex that could be purified by size exclusion chromatography. We prepared different types of viruses devoid of transcriptionally active Tat. They showed a 5- to 10 fold decrease in HIV infectivity, and conversely, encapsidating Tat into ΔTat viruses greatly enhanced infectivity. The absence of encapsidated Tat decreased the efficiency of reverse transcription by ~50% and transcription by more than 90%. We thus identified a Tat-CypA-CA complex that enables Tat encapsidation and showed that encapsidated Tat is required to initiate robust viral transcription and thus viral production at the beginning of cell infection, before neosynthesized Tat becomes available. IMPORTANCE The viral transactivating protein Tat has been shown to stimulate several steps of HIV gene expression. It was found to facilitate reverse transcription. Moreover, Tat is strictly required for the transcription of viral genes. Although the presence of Tat within HIV virions would undoubtedly favor these steps and therefore enable the incoming virus to boost initial viral production, whether and how Tat is present within virions has been a matter a debate. We here described and characterized a tripartite complex between Tat, HIV capsid protein, and the cellular chaperone cyclophilin A that enables efficient and specific Tat encapsidation within HIV virions. We further showed that Tat encapsidation is required for the virus to efficiently initiate infection and viral production. This effect is mainly due to the transcriptional activity of Tat.

Background: Eating disorders (ED) are a public health concern due to their increasing prevalence and severe associated comorbidities. The aim of this study was to identify mental health and health behaviours associated with each form of EDs., Methods: A case-control study was performed: cases were patients with EDs managed for the first time in a specialized nutrition department and controls without EDs were matched on age and gender with cases. Participants of this study filled self-administered paper questionnaire (EDs group) or online questionnaire (non-ED group). Collected data explored socio-demographics, mental health including anxiety and depression, body image, life satisfaction, substances and internet use and presence of IBS (Irritable Bowel Syndrome)., Results: 248 ED patients (broad categories: 66 Restrictive, 22 Bulimic and 160 Compulsive) and 208 non-ED subjects were included in this study. Mean age was 36.0 (SD 13.0) and 34.8 (SD 11.6) in ED and non-ED groups, respectively. Among patients and non-ED subjects, 86.7% and 83.6% were female, respectively. Body Shape Questionnaire mean score was between 103.8 (SD 46.1) and 125.0 (SD 36.2) for EDs and non-ED group, respectively (p < 0.0001). ED patients had a higher risk of unsatisfactory friendly life, anxiety, depression and IBS than non-ED s (all p < 0.0001) Higher risk of anxiety, depression and IBS was found for the three categories of EDs. Higher risk of smoking was associated only with restrictive ED, while or assault history and alcohol abuse problems were associated only with bulimic ED. The risk of binge drinking was lower in all EDs categories than in non-ED., Conclusion: This study highlights the common comorbidities shared by all EDs patients and also identifies some specific features related to ED categories. These results should contribute to the conception of future screening and prevention programs in at risk young population as well as holistic care pathways for ED patients. This case-control study evaluated mental health and health behaviours associated with the main categories of Eating Disorders (EDs). Cases were patients with EDs initiating care in a specialized nutrition department and controls without ED were matched on age and gender with cases. Self-administered paper questionnaires were filled by ED 248 patients (66 Restrictive, 22 Bulimic and 160 Compulsive) and online questionnaire by 241 non-ED controls. Body image satisfaction was significantly worse in ED patients than in controls. (p < 0.0001). Dissatisfactory life, anxiety, depression and irritable bowel syndrome were more found in patients with all EDs categories than in non-ED (p < 0.0001). Smoking risk was increased only in restrictive patients while and assault history and alcohol abuse was increased only in bulimic patients. These results highlight the global burden of ED and related comorbidities and provide useful information for future screening, prevention and care programs., (© 2022. The Author(s).)

Septins are ubiquitous cytoskeletal filaments that interact with the inner plasma membrane and are essential for cell division in eukaryotes. In cellular contexts, septins are often localized at micrometric Gaussian curvatures, where they assemble onto ring-like structures. The behavior of budding yeast septins depends on their specific interaction with inositol phospholipids, enriched at the inner leaflet of the plasma membrane. Septin filaments are built from the non-polar self-assembly of short rods into filaments. However, the molecular mechanisms regulating the interplay with the inner plasma membrane and the resulting interaction with specific curvatures are not fully understood. In this report, we have imaged dynamical molecular assemblies of budding yeast septins on PIP2-containing supported lipid bilayers using a combination of high-speed AFM and correlative AFM-fluorescence microscopy. Our results clearly demonstrate that septins are able to bind to flat supported lipid bilayers and thereafter induce the remodeling of membranes. Short septin rods (octamers subunits) can indeed destabilize supported lipid bilayers and reshape the membrane to form 3D structures such as rings and tubes, demonstrating that long filaments are not necessary for septin-induced membrane buckling.

TAT-RasGAP 317-326 is a cell-penetrating peptide-based construct with anticancer and antimicrobial activities. This peptide kills a subset of cancer cells in a manner that does not involve known programmed cell death pathways. Here we have elucidated the mode of action allowing TAT-RasGAP 317-326 to kill cells. This peptide binds and disrupts artificial membranes containing lipids typically enriched in the inner leaflet of the plasma membrane, such as phosphatidylinositol-bisphosphate (PIP 2 ) and phosphatidylserine (PS). Decreasing the amounts of PIP 2 in cells renders them more resistant to TAT-RasGAP 317-326 , while reducing the ability of cells to repair their plasma membrane makes them more sensitive to the peptide. The W317A TAT-RasGAP 317-326 point mutant, known to have impaired killing activities, has reduced abilities to bind and permeabilize PIP 2 - and PS-containing membranes and to translocate through biomembranes, presumably because of a higher propensity to adopt an α-helical state. This work shows that TAT-RasGAP 317-326 kills cells via a form of necrosis that relies on the physical disruption of the plasma membrane once the peptide targets specific phospholipids found on the cytosolic side of the plasma membrane., Competing Interests: The authors declare no competing interest.

Supported lipid bilayers represent a very attractive way to mimic biological membranes, especially to investigate molecular mechanisms associated with the lateral segregation of membrane components. Observation of these model membranes with high-speed atomic force microscopy (HS-AFM) allows the capture of both topography and dynamics of membrane components, with a spatial resolution in the nanometer range and image capture time of less than 1 s. In this context, we have developed new protocols adapted for HS-AFM to form supported lipid bilayers on small mica disks using the vesicle fusion or Langmuir-Blodgett methods. In this chapter we describe in detail the protocols to fabricate supported artificial bilayers as well as the main guidelines for HS-AFM imaging of such samples.

Influenza virus infection is a serious public health problem in the world, and understanding the molecular mechanisms involved in viral replication is crucial. In this paper, we used a minimalist approach based on a lipid bilayer supported on mica, which we imaged by atomic force microscopy (AFM) in a physiological buffer, to analyze the different steps of influenza fusion, from the interaction of intact viruses with the supported bilayer to their complete fusion. Our results show that sialic acid recognition and priming upon acidification are sufficient for a complete fusion with the host cell membrane. After fusion, a flat and continuous membrane was observed. Because of the fragility of the viral membrane that was removed by the tip, most probably due to the disorganization of the matrix layer at acidic pH, fine structural details of ribonucleoproteins (RNP) were obtained. In addition, AFM topography of intact virus in interaction with the supported lipid bilayer confirms that hemeagglutinin and neuraminidase can form isolated clusters within the viral membrane.

Milk sphingomyelin (MSM) and cholesterol segregate into domains in the outer bilayer membrane surrounding milk fat globules. To elucidate the morphology and mechanical properties of theses domains, supported lipid bilayers with controlled molar proportions of MSM, dioleoylphosphatidylcholine (DOPC) and cholesterol were produced in buffer mimicking conditions of the milk aqueous phase. Atomic force microscopy imaging showed that (i) for T < 35 °C MSM segregated in gel phase domains protruding above the fluid phase, (ii) the addition of 20 mol % cholesterol resulted in smaller and more elongated l(o) phase domains than in equimolar MSM/DOPC membranes, (iii) the MSM/cholesterol-enriched l(o) phase domains were less salient than the MSM gel phase domains. Force spectroscopy measurements furthermore showed that cholesterol reduced the resistance of MSM/DOPC membrane to perforation. The results are discussed with respect to the effect of cholesterol on the biophysical properties of lipid membranes. The combination of AFM imaging and force mapping provides unprecedented insight into the structural and mechanical properties of milk lipid membranes, and opens perspectives for investigation of the functional properties of MSM domains during milk fat processing or digestion.

SpoIIIE/FtsK are a family of ring-shaped, membrane-anchored, ATP-fuelled motors required to segregate DNA across bacterial membranes. This process is directional and requires that SpoIIIE/FtsK recognize highly skewed octameric sequences (SRS/KOPS for SpoIIIE/FtsK) distributed along the chromosome. Two models have been proposed to explain the mechanism by which SpoIIIE/FtsK interact with DNA. The loading model proposes that SpoIIIE/FtsK oligomerize exclusively on SpoIIIE recognition sequence/orienting polar sequences (SRS/KOPS) to accomplish directional DNA translocation, whereas the target search and activation mechanism proposes that pre-assembled SpoIIIE/FtsK hexamers bind to non-specific DNA, reach SRS/KOPS by diffusion/3d hopping and activate at SRS/KOPS. Here, we employ single-molecule total internal reflection imaging, atomic force and electron microscopies and ensemble biochemical methods to test these predictions and obtain further insight into the SpoIIIE-DNA mechanism of interaction. First, we find that SpoIIIE binds DNA as a homo-hexamer with neither ATP binding nor hydrolysis affecting the binding mechanism or affinity. Second, we show that hexameric SpoIIIE directly binds to double-stranded DNA without requiring the presence of SRS or free DNA ends. Finally, we find that SpoIIIE hexamers can show open and closed conformations in solution, with open-ring conformations most likely resembling a state poised to load to non-specific, double-stranded DNA. These results suggest how SpoIIIE and related ring-shaped motors may be split open to bind topologically closed DNA.

The ability to observe interactions of drugs with cell membranes is an important area in pharmaceutical research. However, these processes are often difficult to understand due to the dynamic nature of cell membranes. Therefore, artificial systems composed of lipids have been used to study membrane properties and their interaction with drugs. Here, lipid vesicle adsorption, rupture, and formation of planar lipid bilayers induced by various antibiotics (surfactin, azithromycin, gramicidin, melittin and ciprofloxacin) and the detergent dodecyl-b-D-thiomaltoside (DOTM) was studied using reflective interferometric Fourier transform spectroscopy (RIFTS) on an oxidized porous silicon (pSi) surface as a transducer. The pSi transducer surfaces are prepared as thin films of 3 μm thickness with pore dimensions of a few nanometers in diameter by electrochemical etching of crystalline silicon followed by passivation with a thermal oxide layer. Furthermore, the sensitivity of RIFTS was investigated using three different concentrations of surfactin. Complementary techniques including atomic force microscopy, fluorescence recovery after photobleaching, and fluorescence microscopy were used to validate the RIFTS-based method and confirm adsorption and consequent rupture of vesicles to form a phospholipid bilayer upon the addition of antibiotics. The method provides a sensitive and real-time approach to monitor the antibiotic-induced transition of lipid vesicles to phospholipid bilayers.

SpoIIIE/FtsK are membrane-anchored, ATP-fuelled, directional motors responsible for chromosomal segregation in bacteria. Directionality in these motors is governed by interactions between specialized sequence-recognition modules (SpoIIIE-γ/FtsK-γ) and highly skewed chromosomal sequences (SRS/KOPS). Using a new combination of ensemble and single-molecule methods, we dissect the series of steps required for SRS localization and motor activation. First, we demonstrate that SpoIIIE/DNA association kinetics are sequence independent, with binding specificity being uniquely determined by dissociation. Next, we show by single-molecule and modelling methods that hexameric SpoIIIE binds DNA non-specifically and finds SRS by an ATP-independent target search mechanism, with ensuing oligomerization and binding of SpoIIIE-γ to SRS triggering motor stimulation. Finally, we propose a new model that provides an entirely new interpretation of previous observations for the origin of SRS/KOPS-directed translocation by SpoIIIE/FtsK.

The lipid-layer technique allows reconstituting transmembrane proteins at a high density in microns size planar membranes and suspended to a lipid monolayer at the air/water interface. In this paper, we transferred these membranes onto two hydrophobic substrates for further structural analysis of reconstituted proteins by Atomic Force Microscopy (AFM). We used a mica sheet covered by a lipid monolayer or a sheet of highly oriented pyrolytic graphite (HOPG) to trap the lipid monolayer at the interface and the suspended membranes. In both cases, we succeeded in the transfer of large membrane patches containing densely packed or 2D-crystallized proteins. As a proof of concept, we transferred and imaged the soluble Shiga toxin bound to its lipid ligand and the ATP-binding cassette (ABC) transporter BmrA reconstituted into a planar bilayer. AFM imaging with a lateral resolution in the nanometer range was achieved. Potential applications of this technique in structural biology and nanobiotechnology are discussed., (Copyright © 2011 John Wiley & Sons, Ltd.)

Hepatitis B virus envelope is mainly composed of three forms of the same protein expressed from different start codons of the same open reading frame. The smaller form named S protein corresponds to the C-terminal common region and represents about 80% of the envelope proteins. It is mainly referred as hepatitis B virus surface antigen (HBsAg). Over expressed in the host cell, this protein can be produced as spherical and tubular self-organized particles. Highly immunogenic, these particles are used in licensed hepatitis B vaccines. In this study we have combined transmission electron microscopy and atomic force microscopy to determine the shape and size of HBsAg particles produced from the yeast Hansenula polymorpha. Tapping mode atomic force microscopy in liquid allows structural details of the surface to be delineated with a resolution in the nanometer range. Particles were decorated by closely packed spike-like structures protruding from particle surface. Protrusions appeared uniformly distributed at the surface and an average number of 75 protrusions per particle were calculated. Importantly, we demonstrated that proteins mainly contribute to the topography of the protrusions., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

Purpose: This study assessed the value of high-resolution magnetic resonance imaging (MRI) of the distal colon by means of a dedicated endoluminal magnetic resonance receiver coil on a 1.5-T clinical scanner., Materials and Methods: To this end, single-loop, receive-only radio-frequency coils, housed in 18 F sheaths, were built. A 1.5-T clinical imager was used. A 18 French diameter internal MRI receiver coil was inserted into the distal colon in 15 New Zealand rabbits to obtain high-resolution magnetic resonance images by using T1-weighted Flash sequences with and without Fat Saturation (FS), T2-weighted True-Fisp, turbo spin-echo, and T1-weighted Flash FS after contrast media injection. Images were compared to histological sections., Results: An adequate image quality was obtained in all specimens without significant artefacts. Based on histological reports, a five-layer structure of the wall was considered normal. On different MR sequences, only two layers were identified on the images of all rabbits specimens. The nearest layer to the mucosal surface was usually seen as a hyper intense layer and likely corresponds to the mucosa. The highest difference of signal value between internal and external layers was performed on 2D Fat saturation T1 weighted gradient echo. Comparison of mean signal value between the internal and external layers was statistically different in for each sequence used in our protocol (P < 0.05)., Conclusion: Dedicated endoluminal RF coil provides good spatial resolution at the region of interest. On this prospective study of in vivo rabbit, evaluation of colon walls allowed to provide detailed information.

Aim: To evaluate the value of gadolinium enhanced MRI with oral opacification using a 5% mannitol solution (CE-Mannitol-MRI) to reveal bowel inflammation in pediatric patients with known or suspected Crohn's disease (CD)., Materials and Methods: Sixty-two consecutive children (median age 13.9 years) with known or suspected CD underwent ileocolonoscopy with biopsy, ultrasonography and CE-Mannitol-MRI. CD activity was measured with the Pediatric Crohn's Disease Activity Index (PCDAI). Image quality, wall thickness, bowel wall enhancement and complications identified on CE-Mannitol-MRI were evaluated by two blinded radiologists., Results: The sensitivity and specificity of CE-Mannitol-MRI for the diagnosis of CD were 83% and 100%, respectively. Bowel wall enhancement was higher in the group of patients with abnormal small bowel loops versus control group (P = 0.001). In patients with known CD, there was a positive correlation between wall thickness and PCDAI (P = 0.003). However, no significant correlation was demonstrated between parietal contrast enhancement and PCDAI (P = 0.497). CE-Mannitol-MRI enabled identification of complications in 18 patients (9 fistulae, 8 strictures and 1 intussusception)., Conclusion: In pediatric patients with CD, CE-Mannitol-MRI contributes significantly to the identification of disease extension, severity and intestinal complications with adequate diagnostic accuracy. This technique could also be useful as the first line diagnostic exploration in young patients with suspected CD.

Methylhistamine, histamine's metabolite, was measured in urine by radio-immuno-assay in 79 provocation test. Six of them were positive with clinical symptoms. All of the six were associated with a significant increase of urinary methylhistamine (UMH). Therefore, there is a good correlation between positive provocation tests and increase of UMH level. In these cases, the severity of clinical symptoms is related to the increase of U.M.H.