E-learning versus face-to-face training: Comparison of two learning methods for Lyme borreliosis.

OBJECTIVES: To compare two learning methods for Lyme disease (e-learning versus face-to-face training) to assess knowledge and know-how. METHODS: The study population was volunteer general medicine residents and family physicians (FP). Face-to-face training on Lyme disease was offered to each group. E-learning training was then offered to those who had not attended the face-to-face training. Theoretical knowledge was assessed by an identical pre- and post-test questionnaire and know-how by a script concordance test. RESULTS: Seventy learners (47 FPs and 23 general medicine residents) were included in the face-to-face training group and 61 (33 FPs and 28 general medicine residents) in the e-learning group. The pre- and post-test scores were significantly improved in the FP group (difference of 29.3±1.9 [P<0.0001] out of 100) as well as in the general medicine resident group (difference of 38.2±2.7 [P<0.0001] out of 100). E-learning was more effective than face-to-face training, particularly among general medicine residents (progression of mean difference of 44.3±3.4/100 vs. 30.9±4.0/100; P=0.0138) and to a lesser extent among FPs (progression of 25.3±2.3/100 vs. 31.9±2.7/100; P=0.0757). Forty-six script concordance tests were completed by FPs and 20 by general medicine residents. Script concordance test results did not seem significant between the subgroups. CONCLUSIONS: E-learning seems to be a good alternative to face-to-face training for Lyme disease. It seems to be more effective than face-to-face training for the acquisition of theoretical knowledge. The script concordance test evaluation of know-how did not show any difference between the two learning methods.

Oyster hemolymph is a complex and dynamic ecosystem hosting bacteria, protists and viruses.

BACKGROUND: The impact of the microbiota on host fitness has so far mainly been demonstrated for the bacterial microbiome. We know much less about host-associated protist and viral communities, largely due to technical issues. However, all microorganisms within a microbiome potentially interact with each other as well as with the host and the environment, therefore likely affecting the host health. RESULTS: We set out to explore how environmental and host factors shape the composition and diversity of bacterial, protist and viral microbial communities in the Pacific oyster hemolymph, both in health and disease. To do so, five oyster families differing in susceptibility to the Pacific oyster mortality syndrome were reared in hatchery and transplanted into a natural environment either before or during a disease outbreak. Using metabarcoding and shotgun metagenomics, we demonstrate that hemolymph can be considered as an ecological niche hosting bacterial, protist and viral communities, each of them shaped by different factors and distinct from the corresponding communities in the surrounding seawater. Overall, we found that hemolymph microbiota is more strongly shaped by the environment than by host genetic background. Co-occurrence network analyses suggest a disruption of the microbial network after transplantation into natural environment during both non-infectious and infectious periods. Whereas we could not identify a common microbial community signature for healthy animals, OsHV-1 µVar virus dominated the hemolymph virome during the disease outbreak, without significant modifications of other microbiota components. CONCLUSION: Our study shows that oyster hemolymph is a complex ecosystem containing diverse bacteria, protists and viruses, whose composition and dynamics are primarily determined by the environment. However, all of these are also shaped by oyster genetic backgrounds, indicating they indeed interact with the oyster host and are therefore not only of transient character. Although it seems that the three microbiome components respond independently to environmental conditions, better characterization of hemolymph-associated viruses could change this picture.

Calcium citrate insolubilization drives the fouling of falling film evaporators during the concentration of hydrochloric acid whey.

When dairy powders are produced, the mineral fraction undergoes strong modifications during the vacuum concentration step, leading to the fouling of falling film evaporators. The objective of this study was to determine the nature of the deposits formed during the vacuum concentration of two fouling and highly mineralized products: hydrochloric acid whey and lactic acid whey. These products mainly differ in terms of their mineral composition: lactic acid whey contains a high level of lactic acid and traces of citrate, whereas hydrochloric acid whey contains citrate and no lactic acid. Concentrates at different concentration factors were produced using a pilot-scale falling film evaporator. The compositions of the fouling deposits as well as the precipitates present in the concentrates were deduced from the analytical determination of the composition of the concentrates and their respective diffusible phases. The behavior of the mineral fraction of both acid wheys during concentration was shown to be very different. In the case of hydrochloric acid whey, experimental results suggested a deposition of calcium and citrate ions in the evaporator as well as their precipitation in the highly concentrated products. On the contrary, neither mineral deposition nor precipitation occurred during the concentration of lactic acid whey. This study underlined the key role of citrate ions in the fouling of evaporators during the concentration of hydrochloric acid wheys.

[Unexplicated neuropsychiatric disorders: Do not ignore dysimmune encephalitis. A case report of a dysimmune encephalitis with anti-leucine rich glioma inactivated 1 (LGI-1) antibodies]. / Troubles neuropsychiatriques inexpliqués : penser aux encéphalites dysimmunitaires. À propos d'une observation d'encéphalite à anticorps anti-leucine rich glioma inactivated 1 (LGI-1).

INTRODUCTION: Anti-leucine rich glioma inactivated 1 encephalitis is a common and a treatable etiology of autoimmune encephalitis. Its diagnosis is a challenge because the initial diagnostic work-up is often normal. CASE REPORT: A 48-year-old man experienced cognitive and behavioral troubles, facio-brachial dystonic seizures and a syndrome of inappropriate antidiuretic hormone secretion. First line tests excluded infectious, neoplastic, systemic inflammatory, endrocrine or toxic etiologies. Cerebral (18)Fluoro-desoxy-glucose (FDG) position emission tomography and research of specific antibodies in cerebro-spinal fluid and serum led to diagnose an anti-leucine rich glioma inactivated 1 encephalitis. Intravenous immunoglobulins and corticosteroids were partially effective. Cyclophosphamid permitted a good recovery. CONCLUSION: In the presence of acute neuropsychiatric disorders with a negative etiologic research, physician should think about dysimmune encephalitis. Facio-brachial dystonic seizures and syndrome of inappropriate antidiuretic hormone secretion are highly evocative of anti-leucine rich glioma inactivated 1 encephalitis. The diagnosis needs specific diagnostic tests (cerebral (18)FDG position emission tomography and antibodies research in cerebro-spinal fluid and in serum), after the exclusion of alternative diagnoses. Extensive and repeated diagnostic work-up for neoplasia is required. Immunosupressive therapies are effective in most cases.

[Leber congenital amaurosis: comprehensive survey of genetic heterogeneity. A clinical definition update]. / Amaurose congénitale de Leber: le point sur l'hétérogénéité génétique, actualisation de la définition clinique.

Leber congenital amaurosis (LCA) is the earliest and most severe form of all inherited retinal dystrophies, responsible for congenital blindness. Disease-associated mutations have been hitherto reported in seven genes. These genes are all expressed preferentially in the photoreceptor cells or the retinal pigment epithelium, but they are involved in strikingly different physiologic pathways, resulting in an unforeseeable pathophysiologic variety. This broad genetic and physiologic heterogeneity, which could greatly increase in the coming years, hinders molecular diagnosis in LCA patients. Genotyping is, however, required to establish genetically defined subgroups of patients ready for therapy. Here we report a comprehensive mutational analysis of all the known genes in 179 unrelated LCA patients, including 52 familial and 127 sporadic (27/127 consanguineous) cases. Mutations were identified in 47.5% of patients. GUCY2D accounted for by far the largest part of the LCA cases in our series (21.2%), followed by CRB1 (10%), RPE65 (6.1%), RPGRIP1 (4.5%), AIPL1 (3.4%), TULP1 (1.7%) and CRX (0.6%). The clinical history of all patients with mutations was carefully revisited in the search for phenotype variations. Genotype-phenotype correlations were found that made it possible to divide patients into two main groups. The first one includes patients whose symptoms fit the traditional definition of LCA, i.e., congenital or very early cone-rod dystrophy, while the second group gathers patients affected with severe yet progressive rod-cone dystrophy. In addition, objective ophthalmologic data subdivided each group into two subtypes. Based on these findings, we have drawn decisional flowcharts directing the molecular analysis of LCA genes in a given case. These flowcharts will hopefully lighten the onerous task of genotyping new patients, but only if the most precise clinical history since birth is available.

Total and structured water in cancer: an NMR experimental study of serum and tissues in DMBA-induced OF1 mice.

Total water and structured water (fraction of total water which remains unfrozen below the transition point from the semisolid to solid state) were characterized by 1H NMR relaxometry in the sera and tissues of 3 groups of 30 female mice (C, H and L) receiving a single administration of DMBA and different diets. Mice given the diet H, containing the highest proportion of saturated fatty acids and processed starch, and the lowest phytochemicals content, presented the highest tumor incidence (lymphoma). This allowed 3 subgroups to be defined: subnormal (SN), small (T+) and large tumor (T++). Spin-lattice relaxation times of total water (Tlobs) in the sera and tissues did not significantly differ between C, H and L groups, and SN, T+ and T++ subgroups. In T+ mice, a decrease in the relative amount of structured water was noticed in the serum, liver and heart, while changes in the temperature dependence of the Tl of structured water (Tlsw) were observed between -21 degrees C and -42 degrees C. These results suggest a moderate increase in the rotational mobility of structured water molecules in the serum and the heart, and a pronounced decrease in the liver. Likewise, the modification of the Tlsvv temperature dependence curve's shape tends to confirm the existence of important conformational changes in the macromolecular assemblies, which markedly affect the properties of structured water, especially in the earliest stage of cancer development.

Is up-regulation of phosphodiesterase 4 activity by PGE2 involved in the desensitization of beta-mimetics in late pregnancy human myometrium?

Elevation of cAMP content resulting from stimulation of the receptor-adenylyl cyclase complex is involved in maintaining the quiescence of the human myometrium during pregnancy. The magnitude of this elevation is critically influenced by the rate of cAMP hydrolysis by phosphodiesterase (PDE) isoenzymes. In the present study we report that in term myometrium, enhanced cAMP-specific PDE4 activity takes part in the heterologous desensitization to the beta-mimetic, salbutamol. Indeed, pretreatment with a PDE4-selective inhibitor potentiates the relaxant effect of salbutamol on myometrial strips of women at term. Furthermore, the reduced relaxant effect of salbutamol after long-term treatment of myometrial strips with PGE2, a potent myometrial effector, can be reversed by PDE4 inhibition. Using a model of cultured myometrial cells, we also demonstrated that PGE2 is able to up-regulate PDE4 activity, at least through the induction of synthesis of PDE4B and PDE4D short forms, which, in turn, dampen the cAMP accumulation provoked by the stimulation of adenylyl cyclase. Such data suggest that in late pregnancy endogenous PGE2 might up-regulate PDE4 activity and lessen the responsiveness of myometrium to beta-mimetic activation. Accordingly, coapplication of a selective PDE4 inhibitor might greatly improve the usefulness of beta-mimetic in tocolysis.

Pregnancy induces a modulation of the cAMP phosphodiesterase 4-conformers ratio in human myometrium: consequences for the utero-relaxant effect of PDE4-selective inhibitors.

The inhibitory impacts of RP 73401, a phosphodiesterase type 4 (PDE4) selective inhibitor of the second generation, versus rolipram, the prototypal PDE4 inhibitor, were evaluated and compared on cAMP phosphodiesterase (PDE) activity and contractility of the myometrium in nonpregnant and pregnant women. In enzymatic studies, RP 73401 and rolipram inhibited the cAMP PDE activity with significantly greater maximal efficiency in the myometrium of pregnant compared with nonpregnant women (75 versus 55%; P <.05). Although myometrial PDE4 presented a single class of interaction with RP 73401 [pD(2) (-log [IC(50)]) = -8.2], it exhibited at least two classes of interaction with rolipram (pD(2) = -8.2 and -5.6). In the myometrium of pregnant versus nonpregnant women, rolipram is significantly more efficacious in the concentration range >0.01 to 100 microM (P <.01), whereas no difference was observed for the concentration range <0.01 microM. In contractility studies, RP 73401 was equally effective in relaxing myometrial strips from both nonpregnant and pregnant women (pD(2) = -8.8). Conversely, the ability of rolipram to inhibit contractions of the myometrium in pregnant women was significantly lower (pD(2) = -7.2) compared with that in nonpregnant women (pD(2) = -8.2; P <.01). Concomitantly, in the myometrium of pregnant women, a rise in immunoreactive PDE4B2 signal was detected, whereas the PDE4D3 signal was less intense. These results demonstrate that parallel to an accumulation of PDE4B2 isoform, a modification in the ratio of PDE4 conformers HPDE4 and LPDE4 (conformer that binds rolipram with high and low affinity, respectively) occurs in the myometrium of near-term pregnant women with an increase of LPDE4 functionally implicated in the contractile process. Such modifications provide a strong rationale to propose LPDE4 as potential pharmacologic targets for the design of new tocolytic treatments.

Selective up-regulation of phosphodiesterase-4 cyclic adenosine 3',5'-monophosphate (cAMP)-specific phosphodiesterase variants by elevated cAMP content in human myometrial cells in culture.

In human myometrium, the modulation of intracellular cAMP content resulting from agonist-mediated stimulation of the receptor-adenylyl cyclase complex is largely influenced by the rate of cAMP hydrolysis by phosphodiesterase (PDE) isoenzymes. We have previously shown that the PDE4 family contributes to the predominant cAMP-hydrolyzing activity in human myometrium and that elevation of the PDE4B2 messenger RNA steady state level occurs in pregnant myometrial tissue. In the present study, we used a model of human myometrial cells in culture to determine whether an elevated cAMP concentration could influence PDE expression. As in myometrial tissue, high levels of PDE4 activity were detected in these smooth muscle cells. Long term treatment with 8-bromo-cAMP or forskolin resulted in a selective induction of PDE4B and of PDE4D short form messenger RNA variants. Concurrently, an increased immunoreactive signal for the PDE4B- and PDE4D-related isoenzymes was detected. This induction was consistent with an observed significant up-regulation of PDE4 activity. Accordingly, our results demonstrate that in human cultured myometrial cells, cAMP-elevating agents manipulate PDE4 activity through selective induction of synthesis of PDE4B and PDE4D short forms. Such a mechanism might have physiological importance during pregnancy by dampening hormonal stimulation and could thereby be involved in tolerance to the tocolytic effect of beta-adrenoceptor agonists.

Identification and expression of Go1 and Go2 alpha-subunit transcripts in human myometrium in relation to pregnancy.

The 39-kDa Goalpha protein, the alpha subunit of a major heterotrimeric G protein of brain and neuroendocrine cells, was found to be present in human myometrium. Using three different antisera, we showed its strong expression in myometrium from pregnant patients as compared to nonpregnant ones. This is in agreement with the high expression level of its two isoforms (alphao1 and alphao2), previously described in late pregnancy. To better ascertain the nature of these immunoreactive isoforms, we investigated transcripts of the Goalpha gene in myometrium from pregnant and nonpregnant patients by reverse transcription-polymerase chain reaction (RT-PCR). In this tissue, the amplified cDNA product of a region common to both Go1alpha and Go2alpha mRNA variants was recognized as the Goalpha nucleotide sequence. Transcripts of Go1alpha and Go2alpha were identified by sequencing. A partial cDNA Go2alpha sequence was described, which differed from the Goalpha gene by two nucleotides in exon 8B. Levels of Go1alpha and Go2alpha transcripts analyzed by semi-quantitative RT-PCR were significantly higher in myometrium from pregnant than from nonpregnant patients. It is suggested that Goalpha gene expression in this tissue may contribute to modifications seen in the signaling pathways observed at the end of pregnancy.

Effect of pregnancy on PDE4 cAMP-specific phosphodiesterase messenger ribonucleic acid expression in human myometrium.

In light of the important role of the second messengers cAMP and cGMP in the mechanism of relaxation in the human myometrium, specific regulation of the phosphodiesterase (PDE) enzymatic system responsible for cyclic nucleotide inactivation is essential. We previously identified in the human myometrium PDE4 cAMP-specific PDE as by far the most abundant isoform. Here we have studied the expression patterns of mRNAs for the four cloned human PDE4 genes in the myometria of pregnant and non-pregnant women. Concurrent expression of the PDE4A, 4B, 4C and 4D genes is demonstrated. We found that the PDE4D transcripts are the most prominently expressed. PDE4A and PDE4B mRNAs also are markedly abundant, whereas lower expression is observed for PDE4C mRNAs. Interestingly, we showed that transcripts of PDE4B2 are more abundant in the myometria of pregnant women than in non-pregnant women, whereas no difference between the two tissues was detected for PDE4A, 4C and 4D mRNAs. Cultured human myometrial cells, which present a high level of PDE4 activity and express the four PDE4 mRNA subtypes, provide us with an appropriate model to further evaluate whether the level of expression of the PDE 4B2 mRNA subtype is under hormonal regulation.

Synthesis of Iron Oxide Nanoparticles Used as MRI Contrast Agents: A Parametric Study.

Colloidal iron oxides play an important role as magnetic resonance imaging (MRI) contrast agents. The superparamagnetic particles actually used are constituted by solid cores (diameter of 5-15 nm), generally coated by a thick polysaccharidic layer (hydrodynamic radii of 30-100 nm), and formulated by direct coprecipitation of iron salts in the presence of polymeric material. To better control the synthesis, we attempted to formulate new stable uncoated superparamagnetic nanoparticles. Colloids were generated by coprecipitation of an aqueous solution of iron salts and tetramethylammonium hydroxide (TMAOH) solution. The influence of parameters such as media composition, iron media, injection fluxes, Fe and TMAOH concentrations, temperature, and oxygen on size, magnetic and magnetic resonance relaxometric properties, and colloidal stability of particles were evaluated. We have determined the relative importance of these parameters as well as the optimal conditions for obtaining uncoated stable particles with an average size of 5 nm and interesting relaxivities. The interpretation of the observed limits takes into account diffusibilities of reactants and product, feeding rates of reactants, and surface properties of nanoparticles. A model of synthesis, related to spontaneous emulsification of suspensions, is proposed. Copyright 1999 Academic Press.

Phosphorylcholine Coating of Iron Oxide Nanoparticles.

In order to develop thin-walled superparamagnetic nanoparticle suspensions as a contrast agent for magnetic resonance imaging, phosphorylcholine PC was used to coat iron oxide cores of 5 nm. Weak stable positively charged suspensions can be obtained at concentration greater than 3 mmol.l-1 (corresponding to about 3.2 molecules per nm2), while the addition of phosphorylglycerol PG decreases the electrophoretic mobility. Raising the pH over 6 leads to flocculation: the binding of PC on iron oxides as a function of pH appears to be reversible. By Langmuir analysis, two adsorption domains may be observed with a maximal density of 3.48 and 6.55 mol.nm-2, interpreted as a multilayer formation. Copyright 1999 Academic Press.

[Measurement of the quality of life in chronic hepatitis C: validation of a general index and specific index. First French results]. / Mesure de la qualité de vie chez les malades ayant une hépatite chronique virale C: validation d'un indicateur général et d'un indicateur spécifique.

OBJECTIVES: To report the validation of 2 questionnaires of quality of life in chronic hepatitis C and the first results in 100 patients. METHODS: The questionnaire included 118 items and took 30 to 45 minutes to answer. It included a general index, the Nottingham Health Profile, with 38 items in 6 themes (physical mobility, social isolation, emotional reactions, pain, sleep and energy) and a specific index, the Montpellier Specific Index, with 80 items in 7 themes: symptoms, food, alcohol and tobacco, work, relations with other people, perception of disease. RESULTS: The questionnaires were self-administered to the 100 first patients with chronic hepatitis C without cirrhosis before treatment; 55 men, 45 women, average age 40 year-old, median Knodell's score 8 and median METAVIR score A2 F1. Reduction in the quality of life was frequent and was not highly correlated with biological, virological and histological parameters; it was associated with psychological disorders, reduced sexuality and apprehension of the future. CONCLUSION: This study showed the feasibility, validation, sensitivity and agreement of a quality of life questionnaire, which included a general index and a specific index of chronic hepatitis C in France. These initial results must be confirmed in studies during antiviral treatment of patients.

Isolation and characterization of the rolipram-sensitive cyclic AMP-specific phosphodiesterase (type IV PDE) in human term myometrium.

On the basis of the potencies of classical selective modulators of cyclic nucleotide phosphodiesterase (PDE) activities, five cyclic nucleotide PDE isoforms have been isolated and characterized in the cytosolic fraction of human term myometrium. By means of successive ion-exchange chromatographies, a calcium-calmodulin sensitive isoform, a cyclic GMP-stimulated isoform, a cyclic GMP-inhibited isoform, a rolipram-sensitive cyclic AMP-specific isoform and a cyclic GMP-specific isoform, corresponding to PDE I, PDE II, PDE III, PDE IV and PDE V, respectively, have been identified. We found that near term, human myometrium contains a higher proportion of the rolipram-sensitive type IV PDE isoform (about 50% of total cyclic AMP hydrolytic activity) than the type III cyclic GMP-inhibited PDE isoform (only 10%). Type IV PDE displays simple Michaelis-Menten kinetics with a high affinity for cyclic AMP (Km approximately 4.4 microM) and is selectively and competitively inhibited by rolipram (K(i) approximately 0.9 microM) and Ro 20-1724 (K(i) approximately 2.6 microM). The predominance of type IV PDE at the end of pregnancy suggests that this isoform contributes, via a modulation of the intracellular cyclic AMP level, to local control of uterine motility and thus could help the myometrium prepare for pronounced contractile activity at the time of parturition.