Clinical Utility of 18F-FDG PET/CT in the Work-up of Children with Uveitis.

PURPOSE: To evaluate 18F-fluorodeoxyglucose Positron Emission Tomography/ultra low dose Computed Tomography (18F-FDG PET/ ULD CT) in the work-up of pediatric uveitis. METHODS: Retrospective study of 12 children followed for uveitis who underwent whole body 18F-FDG PET/ULD CT between 2011 and 2019. RESULTS: The average age of the patients was 11 years. A total of 100% of patients presented with bilateral uveitis, 50% had panuveitis and 92% had various choroidal involvement. Relevant information for diagnosis was provided in four patients. 5/12 had an abnormal 18F-FDG uptake. Of these, three patients had pathognomonic images of active granulomatous diseases. Three patients underwent PET CT-guided biopsies of which two were positive for sarcoidosis. CONCLUSION: 18F-FDG PET/CT provided important information for final diagnosis in approximately 30% (4/12) of pediatric patients with bilateral uveitis. Whole body FDG PET/ULD CT can contribute to the final diagnosis thanks to pathognomonic image of active granulomatous disease and/or by indicating metabolically active site of biopsy that would not be visualized in thorax CT.

[An atypical case of systemic juvenile idiopathic arthritis]. / Un cas atypique d'arthrite juvénile idiopathique systémique.

The systemic juvenile idiopathic arthritis (SJIA) is a rare, auto-inflammatory and chronic childhood disease. Arthritis of at least one joint is associated with a daily fever lasting more than two weeks and with one of the following signs: lymphadenopathy, hepatomegaly, serositis, or skin rash. Systemic symptoms are often initially preponderant, in the absence of arthritis than can occur weeks or months later. The typical rash is maculopapular discrete, fleeting and dew. We present an unusual SJIA case, where the rash, like urticaria, presents itself as persistent, itchy hives. An arthritis of the elbow appeared only one month after the onset of the disease. This case illustrates the difficulty of diagnosis, which can only be made after the exclusion of more common (infectious) and severe (hematooncology) diseases.

L'arthrite juvénile idiopathique systémique (AJIS) est une maladie rare, auto-inflammatoire et chronique de l'enfant. Le tableau associe la présence d'une arthrite touchant au moins une articulation, à une fièvre quotidienne d'une durée minimum de 2 semaines et à l'un des signes suivants : adénopathies, hépatomégalie, sérosite ou éruption cutanée. Les symptômes systémiques sont souvent prépondérants initialement, en l'absence d'arthrite avérée qui peut n'apparaître qu'après plusieurs semaines ou mois. L'éruption typique est maculo-papuleuse rosée discrète et fugace. Nous présentons un cas atypique d'AJIS, dont l'éruption se présente comme une urticaire persistante et prurigineuse. Une arthrite du coude n'est apparue qu'un mois après le début de l'affection. Ce cas illustre la difficulté du diagnostic qui ne peut être posé qu'après l'exclusion de pathologies plus courantes (infectieuses) et plus graves (hémato-oncologiques).

A custom robot for Transcranial Magnetic Stimulation: first assessment on healthy subjects.

In this paper, a custom robotic system for Transcranial Magnetic Stimulation is assessed in clinical conditions on healthy subjects. A motor cortex mapping is performed using the robotic system with comparison to a manual approach using a neuronavigation system. Stimulation accuracy, repeatability are evaluated as well as the feeling of the system operator and the subject in terms of comfort, tiredness, stress level, ease-of-use. Very encouraging results are obtained on all these aspects, which strengthens the idea of developing robotic assistance for TMS.

Oral ulceration: an unusual manifestation of Churg-Strauss syndrome.

Churg-Strauss Syndrome (CSS) is a relatively rare entity characterized by asthma, transient pulmonary infiltrates, eosinophilia and systemic vasculitis. Oral ulceration is a possible clinical manifestation of some systemic vasculitides, such as Wegener's granulomatosis (WG) or giant cell arteritis, but has never been reported with Churg-Strauss syndrome. We report the first observation of a palatine ulceration in a 15-year-old girl with Churg-Strauss syndrome.

Insulin-dependent diabetes mellitus as long term complication of haemolytic-uraemic syndrome.

Haemolytic-uraemic syndrome (HUS) is a rare cause of insulin-dependent diabetes mellitus during the acute stage. We previously reported the case of a 3-year-old girl having presented with typical HUS with diarrhea, microangiopathic anaemia, thrombocytopenia and acute renal failure (17 days of anuria). Transient hyperglycaemia (highest level: 513 mg/dl) was observed, requiring continuous intravenous insulin infusion for 9 days. Subcutaneous insulin injections were stopped after 24 days. Oral glucose tolerance test performed 4 months after normalization of blood glucose was normal. HLA DQ genotype (DQA1-DQB1.AZH/DQA3-DQB3.1) was not at risk for type 1 diabetes and there were no auto-antibodies (ICA and IAA). The 3-years follow-up was marked by persistent arterial hypertension, proteinuria and slight renal insufficiency despite angiotensin-converting enzyme inhibitor treatment. Ten years after HUS occurred (the patient had been lost to follow-up for 7 years), she came back with complaints of headache but neither polyurodipsia nor weight loss. She was found to have arterial hypertension. Chronic renal impairment had moderately progressed with decreased glomerular filtration rate (63 ml/min/1.73 m2) and proteinuria (2 g/24 hours). Fasting blood glucose was 189 mg/dl and reached 315 mg/dl during an oral glucose tolerance test. HbA1c level was 8.2% (N<6.2%) and diabetes mellitus was diagnosed without any signs of autoimmunity (IAA, ICA, GADA and IA2B were negative). Good glycaemic control was obtained with 0.5 U/kg/day of insulin. In conclusion, transient beta-cell dysfunction complicating HUS acute stage may evolve to overt non-autoimmune diabetes mellitus (microangiopathic process?), even after a long free interval. This case emphasizes the need for a long-term follow-up of patients with HUS.

CD8beta endows CD8 with efficient coreceptor function by coupling T cell receptor/CD3 to raft-associated CD8/p56(lck) complexes.

The extraordinary sensitivity of CD8+ T cells to recognize antigen impinges to a large extent on the coreceptor CD8. While several studies have shown that the CD8beta chain endows CD8 with efficient coreceptor function, the molecular basis for this is enigmatic. Here we report that cell-associated CD8alphabeta, but not CD8alphaalpha or soluble CD8alphabeta, substantially increases the avidity of T cell receptor (TCR)-ligand binding. To elucidate how the cytoplasmic and transmembrane portions of CD8beta endow CD8 with efficient coreceptor function, we examined T1.4 T cell hybridomas transfected with various CD8beta constructs. T1.4 hybridomas recognize a photoreactive Plasmodium berghei circumsporozoite (PbCS) peptide derivative (PbCS (4-azidobezoic acid [ABA])) in the context of H-2K(d), and permit assessment of TCR-ligand binding by TCR photoaffinity labeling. We find that the cytoplasmic portion of CD8beta, mainly due to its palmitoylation, mediates partitioning of CD8 in lipid rafts, where it efficiently associates with p56(lck). In addition, the cytoplasmic portion of CD8beta mediates constitutive association of CD8 with TCR/CD3. The resulting TCR-CD8 adducts exhibit high affinity for major histocompatibility complex (MHC)-peptide. Importantly, because CD8alphabeta partitions in rafts, its interaction with TCR/CD3 promotes raft association of TCR/CD3. Engagement of these TCR/CD3-CD8/lck adducts by multimeric MHC-peptide induces activation of p56(lck) in rafts, which in turn phosphorylates CD3 and initiates T cell activation.

Genetic and biochemical characterization of mutations affecting the carboxy-terminal domain of the Escherichia coli molecular chaperone DnaJ.

DnaJ is a universally conserved heat shock protein involved in protein folding. DnaJ contains four conserved domains. The N-terminal 'J-domain' has been shown to be responsible for the recruitment of its specific DnaK partner protein. The 'Gly/Phe'- and 'Cys-rich' domains have been implicated in stabilizing interactions with DnaK. DnaJ is also able to interact independently with unfolded or native polypeptides. Very little is known regarding such binding/chaperone abilities, but it has been suggested that the least conserved carboxy-terminal domain could contribute to these properties. To gain insight into the biological activity of this fourth domain, we deleted two relatively conserved patches of amino acid residues, a 'G-rich' cluster and a 'G-D-L-Y-V' motif, resulting in the DnaJDelta[230-238] and DnaJDelta[242-246] mutant proteins respectively. Both mutant proteins are partially defective in stimulating the ATPase activity of DnaK and in preventing aggregation of firefly luciferase in vitro. Both mutants have lost the ability to regulate the sigma32-dependent heat shock response, as shown in vivo using a heat shock transcriptional fusion. Furthermore, and unlike wild-type DnaJ, DnaJDelta[242-246] is unable to assist the DnaK-dependent refolding of denatured luciferase. In agreement with these results, we found that DnaJDelta[242-246] is unable to restore either the temperature-sensitive phenotype or the motility defect of a dnaJ null mutation. Substitution of amino acids [242-246] by five alanines leads to similar phenotypic defects, suggesting that altering the 'G-D-L-Y-V' motif leads to partial loss of DnaJ activity. Our data clearly support a role in the intrinsic chaperone/substrate binding ability of the carboxy-terminal domain of DnaJ.

In vivo and in vitro folding of a recombinant metalloenzyme, phosphomannose isomerase.

Phosphomannose isomerase (PMI) catalyses the interconversion of mannose 6-phosphate and fructose 6-phosphate in prokaryotic and eukaryotic cells. The enzyme is a metalloenzyme which contains 1 mol of zinc per mol of enzyme. Heterologous expression of the cDNA coding for the Candida albicans enzyme in the prokaryotic host Escherichia coli results in an expression level of up to 30% of total E. coli protein. Ten percent of recombinant PMI is expressed in the soluble fraction and 90% in inclusion bodies. Inclusion of a high level of zinc in the fermentation medium resulted in a fourfold increase in soluble protein. Co-expression of the bacterial chaperones, GroES and GroEL, resulted in a proportional twofold increase in soluble PMI while causing an overall decrease in the PMI expression level. Folding denatured PMI in vitro required reductant and zinc ions. The yield of renatured protein was increased by folding in the presence of GroEL and DnaK in an ATP-independent manner. The refolding yield of denatured soluble enzyme from a guanidine solution was threefold higher than that of folding monomerized inclusion body protein solubilized in guanidine hydrochloride. This suggests that a proportion of recombinant protein expressed in E.coli inclusion bodies may be irreversibly denatured.

The Escherichia coli heat shock response and bacteriophage lambda development.

The Escherichia coli/bacteriophage lambda genetic interaction system has been used to uncover the existence of various biological machines. The starting point of all these studies was the isolation and characterization of E. coli mutants that blocked lambda growth, and the corresponding lambda compensatory mutations. In this manner, the lambda N-promoted transcriptional anti-termination machine was discovered composed of the NusA/NusB/NusE/NusG host proteins. In addition, the DnaK and GroEL chaperone machines were discovered composed of DnaK/DnaJ/GrpE and GroES/GroEL heat shock proteins. The individual members of the DnaK and GroEL chaperone machines have been conserved throughout evolution in both function and structure. Their biological roles include a direct involvement in lambda DNA replication and morphogenesis, the protection of proteins from aggregation, the disaggregation of various protein aggregates, the manipulation of protein structure and function, as well as the autoregulation of the heat shock response. The evolution of lambda to extensively rely on the status of the heat shock response of E. coli is likely linked to its lytic versus lysogenic choice of lifestyle. The bacteriophage T4 gp31 protein has been purified and shown to substitute for many of GroES' co-chaperonin activities.

[Epidemiological study of caries prevalence in 5-and-12-year-old school children in Flanders]. / Etude épidémiologique de la prévalence de caries chez les écoliers de 5 et 12 ans en Flandre.

A caries prevalence survey was carried out among twelve and five-year-old school children in Flanders (Belgium). The aim of the study was an evaluation of the education, prevention and treatment programme organised by the Flemish Working Group on Oral Prevention. The survey covered 3600 5-year old children and as many 12-year old adolescents, selected at random in the five Dutch-speaking provinces of Belgium. Concerning the caries experience of 5-year old children, we noticed a small dmft of 1.65 and a percentage of caries-free of 60%. Regarding the results for the 12-year olds, we recorded a DMFT of 2.72 and 25% caries-free adolescents. Children from non West-European origin scored much higher in dmft but showed a remarkably lower DMFT-index. We can suggest that an increased attention remains necessary for risk groups such as children with a high caries susceptibility, young immigrants and low income families. The dental health education in schools should be kept on-going and even be extended towards adolescents. Because we remarked a very low dental attendance pattern among young children, we really need to convince parents of the importance of early visits to the dentist. We believe that epidemiology is the only basis for a sound and evident prevention strategy.

[Clinical comparison between alprazolam and lorazepam. A polycentric study in double blind]. / Comparaison clinique entre alprazolam et lorazepam. Une étude polycentrique en double insu.

The clinical efficacy and safety of alprazolam was compared to lorazepam in a double blind randomized design involving 82 out-patients suffering from primary anxiety. Seventy four patients (37 on alprazolam and 37 on lorazepam) were evaluable. They were treated with a flexible dose of 0,75 mg to 3 mg of alprazolam per day (average final dose: 1,59 mg) or 3 mg to 12 mg of lorazepam per day (average final dose: 5,97 mg). The results show that the two drugs produce similar efficacious effects at weeks 2 and 4 of the treatment as evaluated using both patient and physician scales. At week 1, as could be expected from an average daily dose of 0,99 mg of alprazolam and of 4,14 mg of lorazepam, efficacy parameters favored lorazepam. Fifty seven side effects were reported in the 37 lorazepam patients while 61 side effects were reported in the 37 alprazolam patients.