Increased eotaxin in tears of patients wearing contact lenses

Résumé Introduction : La conjonctivite giganto-papillaire chez des patients porteurs de lentilles de contact survient lors d'une intolérance et/ou d'une allergie aux lentilles de contact. L'éotaxine est un CC chémokine produisant un puissant effet chémotactique sur les éosinophiles, qui sont impliqués dans les allergies. Le but de cette étude est de mesurer le taux d'éotaxine dans les larmes de patients porteurs de lentilles de contact et de le comparer à celui de sujets normaux. Les taux d'éotaxine sont également corrélés avec le degré de conjonctivite giganto-papillaire. Méthode : Environ 10 Ill de larmes ont été collectés avec une rnicropipette en verre chez 16 patients porteurs de lentilles de contact et chez 10 volontaires normaux. La conjonctivite giganto-papillaire a été évaluée selon une échelle de 0 à 4 en référence à des images photographiques de la paupière supérieure réalisées à la lampe à fente. La concentration de l'éotaxine dans les larmes a été mesurée par un ELISA utilisant un anticorps d'éotaxine de souris dirigé contre l'anticorps humain. Pour l'analyse statistique des résultats, le test de Wilcox/Kruskal-Wallis a été utilisé. Résultats : La concentration moyenne d'éotaxine était de 2698 +233 (SEM) pg/ml chez les patients porteurs de lentilles de contact et de 1498 139 pg/ml chez les sujets normaux. La différence était statistiquement significative avec P = 0.0004. Le score moyen des papilles était de 1.75 ±0.19 chez les patients porteurs de lentilles de contact et de 0.2 +0.13 chez les sujets normaux (P <0.0001). Le grading des papilles a pu être mis en relation avec le taux d'éotaxine dans les larmes (R2- 0.6562 avec P <0.0001). Conclusion : Une augmentation du taux d'éotaxine dans les larmes a été mesurée chez les patients porteurs de lentilles de contact. Les taux d'éotaxine ont été corrélés avec la sévérité de la conjonctivite giganto-papillaire. Ces données suggèrent que l'éotaxine pourrait jouer un rôle important dans la formation des papilles. Abstract : Purpose: Giant papillary conjunctivitis in patients wearing contact lenses occurs after intolerance and/or allergy to contact lenses. Eotaxin is a CC chemokine with a potent and specific chemotactic effect for eosinophils, which are involved in allergies. The purpose of this study is to measure the eotaxin levels in tears of patients wearing contact lenses and in normal subjects. Eotaxin levels were also correlated with the grade of giant papillary conjunctivitis. Methods: Around 10µL of tears were collected with glass capillaries in 16 patients wearing contact lenses and in 10 normal volunteers. Giant papillary conjunctivitis was graded from 0 to 4 by reference to standard slit-lamp photographs of the superior tarsal conjunctiva. Eotaxin concentration in tears was measured by ELSA using mouse anti-human eotaxin monoclonal antibodies. For the statistical analysis of the results, the paired Wilcoxon/Kruskai-Wallis test was used. Results: The mean concentration of eotaxin was 2698 ± 233 (SEM) pg/mL in patients wearing contact lenses and 1498 ± 139 pg/mL normal subjects. The difference was statistically significant (P =0.0004). The mean score of papilla grade was 1.75 ± 0.19 in patients wearing contact lenses and 01 ± 0.13 in normal subjects (P < 0.0001). Papilla grade could be correlated to the eotaxin level in tears (R2 = 0.6562 and P< 0.0001), Conclusion: An increase of eotaxin levels in tears was measured in patients wearing contact lenses. Eotaxin levels correlated with the severity of giant papillary conjunctivitis. These data suggest that eotaxin could play a role in papilla formation.

Genetic redox dysregulation induces behavioural deficits in the adult mouse: an animal model for schizophrenia

Background: Glutathione (GSH), a major cellular redox regulator and antioxidant, is decreased in cerebrospinal fluid and prefrontal cortex of schizophrenia patients. The gene of the key GSH-synthesizing enzyme, glutamate-cysteine ligase, modifier (GCLM) subunit, is associated with schizophrenia, suggesting that the deficit in the GSH system is of genetic origin. Using the GCLM knock-out (KO) mouse as model system with 60% decreased brain GSH levels and, thus, strong vulnerability to oxidative stress, we have shown that GSH dysregulation results in abnormal mouse brain morphology (e.g., reduced parvalbumin, PV, immuno-reactivity in frontal areas) and function. Additional oxidative stress, induced by GBR12909 (a dopamine re-uptake inhibitor), enhances morphological changes even further. Aim: In the present study we use the GCLM KO mouse model system, asking now, whether GSH dysregulation also compromises mouse behaviour and cognition. Methods: Male and female wildtype (WT) and GCLM-KO mice are treated with GBR12909 or phosphate buffered saline (PBS) from postnatal day (P) 5 to 10, and are behaviourally tested at P 60 and older. Results: In comparison to WT, KO animals of both sexes are hyperactive in the open field, display more frequent open arm entries on the elevated plus maze, longer float latencies in the Porsolt swim test, and more frequent contacts of novel and familiar objects. Contrary to other reports of animal models with reduced PV immuno-reactivity, GCLM-KO mice display normal rule learning capacity and perform normally on a spatial recognition task. GCLM-KO mice do, however, show a strong deficit in object-recognition after a 15 minutes retention delay. GBR12909 treatment exerts no additional effect. Conclusions: The results suggest that animals with impaired regulation of brain oxidative stress are impulsive and have reduced behavioural control in novel, unpredictable contexts. Moreover, GSH dysregulation seems to induce a selective attentional or stimulus-encoding deficit: despite intensive object exploration, GCLM-KO mice cannot discriminate between novel and familiar objects. In conclusion, the present data indicate that GSH dysregulation may contribute to the manifestation of behavioural and cognitive anomalies that are associated with schizophrenia.

The neonatal Fc receptor is not required for mucosal infection by mouse mammary tumor virus.

The milk-borne mouse mammary tumor virus (MMTV) infects newborn mice via the intestine. Infection is initially restricted to Peyer's patches and later spreads to the epithelial cells of the mammary gland. The receptor that mediates uptake and transport of MMTV across the intestinal barrier has not yet been identified, The neonatal Fc receptor (nFcR), which is expressed by enterocytes during the first two weeks of life, is downregulated at weaning, and its disappearance correlates with the onset of intestinal resistance to MMTV. To test whether the nFcR mediates transport and allows infection, we foster nursed on infected MMTV mothers beta2 microglobulin-deficient (beta2m-deficient) newborn mice that are unable to express the nFcR at the surface of their enterocytes. Exposure of beta2m-deficient mice to milk-borne virus resulted in the deletion of peripheral blood T cells reactive to the superantigen encoded by MMTV. Since beta2m-deficient newborn mice are susceptible to MMTV infection despite the lack of the nFcR, we conclude that the nFcR is not required for MMTV transport.

Antigen-secretory IgA immune complexes are retro-transported into mouse Peyer's patches: immunotargeting to dendritic cells

RÉSUMÉ Les plaques de Peyer (PP) représentent le site d'entrée majeur des pathogènes au niveau des muqueuses intestinales. Après avoir traversé la cellule M, l'antigène est pris en charge par les cellules dendritiques (DC) de la région sub-épithéliale du dôme des PP. Ces dernières activent une réponse immunitaire qui conduit à la production de l'IgA de sécrétion (SIgA), l'anticorps majeur au niveau muqueux. Des études précédentes dans notre laboratoire ont démontré qu'après administration de SIgA dans des anses intestinales de souris, les SIgA se lient spécifiquement aux cellules M, entrent dans les PP, et sont éventuellement internalisées par les DC. Le but de ce travail est de comprendre la relevance biologique de l'entrée des SIgA dans les PP et leur relevance physiologique dans l'homéostasie mucosale. Dans un premier temps, nous avons montré en utilisant une méthode de purification optimisée basée sur une isolation magnétique, que, en plus des DC myéloïdes (CD11c+/CD11b+) et des DC lymphoïdes (CD11c+/CD8+), les PP de souris contiennent un nouveau sous-type de DC exprimant les marqueurs CD11c et CD19. L'utilisation de la microscopie confocale nous a permis de démontrer que les DC myéloïdes internalisent des SIgA, contrairement aux DC lymphoïdes qui n'interagissent pas avec les SIgA, alors que le nouveau sous-type de DC exprimant CD19 lie les SIgA. En plus, nous avons démontré qu'aucune des DC de rate, de ganglion bronchique ou de ganglion inguinal interagit avec les SIgA. Dans le but d'explorer si les SIgA peuvent délivrer des antigènes aux DC des PP in vivo, nous avons administré des complexes immunitaires formés de Shigella flexneri complexées à des SIgA, dans des anses intestinales de souris. Nous avons observé une entrée dans les PP, suivie d'une migration vers les ganglions mésentériques drainants, contrairement aux Shigella flexneri seules, qui n'infectent pas la souris par la voie intestinale. Shigella flexneri délivrée par SIgA n'induit pas de destruction tissulaire au niveau de l'intestin. En plus de l'exclusion immunitaire, ces résultats suggèrent un nouveau rôle des SIgA, qui consiste à transporter des antigènes à l'intérieur des PP dans un contexte non-inflammatoire. RÉSUMÉ DESTINÉ À UN LARGE PUBLIC L'intestin a pour rôle principal d'absorber les nutriments digérés tout au long du tube digestif, et de les faire passer dans le compartiment intérieur sanguin. Du fait de son exposition chronique avec un monde extérieur constitué d'aliments et de bactéries, l'intestin est un endroit susceptible aux infections et a donc besoin d'empêcher l'entrée de microbes. Pour cela, l'intestin est tapissé de "casernes" appelées les plaques de Peyer, qui appartiennent à un système de défense appelé système immunitaire muqueux. Les plaques de Peyer sont composées de différents types de cellules, ayant pour rôle de contrôler l'entrée de microbes et de développer une réaction immunitaire lors d'infection. Cette réaction immunitaire contre les microbes (antigènes) débute par la prise en charge de l'antigène par des sentinelles, les cellules dendritiques. L'antigène est préparé de façon à être reconnu par d'autres cellules appelées lymphocytes T capables d'activer d'autres cellules, les lymphocytes B. La réaction immunitaire résulte dans la production par les lymphocytes B d'un anticorps spécifique appelé IgA de sécrétion (SIgA) au niveau de la lumière intestinale. De manière classique, le rôle de SIgA au niveau de la lumière intestinale consiste à enrober les microbes et donc exclure leur entrée dans le compartiment intérieur. Dans ce travail, nous avons découvert une nouvelle fonction des SIgA qui consiste à introduire des antigènes dans les plaques de Peyer, et de les diriger vers les cellules dendritiques. Sachant que les SIgA sont des anticorps qui ne déclenchent pas de réactions de défense violentes dites inflammatoires, l'entrée des antigènes via SIgA serait en faveur d'une défense intestinale maîtrisée sans qu'il y ait d'inflammation délétère. Ces résultats nous laissent supposer que l'entrée d'antigènes via SIgA pourrait conduire le système immunitaire muqueux à reconnaître ces antigènes de manière appropriée. Ce mécanisme pourrait expliquer les désordres immunitaires de types allergiques et maladies auto-immunitaires que l'on rencontre chez certaines personnes déficientes en IgA, chez qui cette lecture d'antigènes de manière correcte serait inadéquate. ABSTRACT Peyer's patches (PP) represent the primary site for uptake and presentation of ingested antigens in the intestine. Antigens are sampled by M cells, which pass them to underlying antigen-presenting cells including dendritic cells (DC). This leads to the induction of mucosal T cell response that is important for the production of secretory IgA (SIgA), the chief antibody at mucosal surfaces. Previous studies in the laboratory have shown that exogenous SIgA administrated into mouse intestinal loop binds specifically to M cells, enter into PP, and is eventually internalized by DC. The aim of this work is to understand the biological significance of the SIgA uptake by PP DC and its physiological relevance for mucosal homeostasis. As a first step, we have shown by using an optimized MACS method that, in addition to the CD11c+/CD11b+ (myeloid DC) and CD11c+/CD8+ (lymphoid DC) subtypes, mouse PP contain a novel DC subtype exhibiting both CD11c and CD19 markers. By using a combination of MACS isolation and confocal microscopy, we have demonstrated that in contrast to the lymphoid DC which do not interact with SIgA, the myeloid DC internalize SIgA, while the CD19+ subtype binds SIgA on its surface. Neither spleen DC, nor bronchial-lymph node DC, nor inguinal lymph node DC exhibit such a binding specificity. To test whether SIgA could deliver antigens to PP DC in vivo, we administered SIgA-Shigella flexneri immune complexes into mouse intestinal loop containing a PP. We found that (i) SIgA-Shigella flexneri immune complexes enter the PP and are internalized by sub-epithelial dome PP DC, in contrast to Shigella flexneri alone that does not penetrate the intestinal epithelia in mice, (ii) immune complexes migrate to the draining mesenteric lymph node, (iii) Shigella flexneri carried via SIgA do not induce intestinal tissue destruction. Our results suggest that in addition to immune exclusion, SIgA transports antigens back to the PP under non-inflammatory conditions.

Is there an advantage to be gained from adding digital image cytometry of brush cytology to a standard biopsy protocol in patients with Barrett's esophagus?

BACKGROUND AND STUDY AIMS: The current gold standard in Barrett's esophagus monitoring consists of four-quadrant biopsies every 1-2 cm in accordance with the Seattle protocol. Adding brush cytology processed by digital image cytometry (DICM) may further increase the detection of patients with Barrett's esophagus who are at risk of neoplasia. The aim of the present study was to assess the additional diagnostic value and accuracy of DICM when added to the standard histological analysis in a cross-sectional multicenter study of patients with Barrett's esophagus in Switzerland. METHODS: One hundred sixty-four patients with Barrett's esophagus underwent 239 endoscopies with biopsy and brush cytology. DICM was carried out on 239 cytology specimens. Measures of the test accuracy of DICM (relative risk, sensitivity, specificity, likelihood ratios) were obtained by dichotomizing the histopathology results (high-grade dysplasia or adenocarcinoma vs. all others) and DICM results (aneuploidy/intermediate pattern vs. diploidy). RESULTS: DICM revealed diploidy in 83% of 239 endoscopies, an intermediate pattern in 8.8%, and aneuploidy in 8.4%. An intermediate DICM result carried a relative risk (RR) of 12 and aneuploidy a RR of 27 for high-grade dysplasia/adenocarcinoma. Adding DICM to the standard biopsy protocol, a pathological cytometry result (aneuploid or intermediate) was found in 25 of 239 endoscopies (11%; 18 patients) with low-risk histology (no high-grade dysplasia or adenocarcinoma). During follow-up of 14 of these 18 patients, histological deterioration was seen in 3 (21%). CONCLUSION: DICM from brush cytology may add important information to a standard biopsy protocol by identifying a subgroup of BE-patients with high-risk cellular abnormalities.

Vasopressin-dependent coupling between sodium transport and water flow in a mouse cortical collecting duct cell line.

Water balance is achieved through the ability of the kidney to control water reabsorption in the connecting tubule and the collecting duct. In a mouse cortical collecting duct cell line (mCCD(c11)), physiological concentrations of arginine vasopressin increased both electrogenic, amiloride-sensitive, epithelial sodium channel (ENaC)-mediated sodium transport measured by the short-circuit current (Isc) method and water flow (Jv apical to basal) measured by gravimetry with similar activation coefficient K(1/2) (6 and 12 pM, respectively). Jv increased linearly according to the osmotic gradient across the monolayer. A small but highly significant Jv was also measured under isoosmotic conditions. To test the coupling between sodium reabsorption and water flow, mCCD(c11) cells were treated for 24 h under isoosmotic condition with either diluent, amiloride, vasopressin or vasopressin and amiloride. Isc, Jv, and net chemical sodium fluxes were measured across the same monolayers. Around 30% of baseline and 50% of vasopressin-induced water flow is coupled to an amiloride-sensitive, ENaC-mediated, electrogenic sodium transport, whereas the remaining flow is coupled to an amiloride-insensitive, nonelectrogenic sodium transport mediated by an unknown electroneutral transporter. The mCCD(c11) cell line is a first example of a mammalian tight epithelium allowing quantitative study of the coupling between sodium and water transport. Our data are consistent with the 'near isoosmotic' fluid transport model.

Early neutralizing antibody response against mouse mammary tumor virus: critical role of viral infection and superantigen-reactive T cells.

Infectious mouse mammary tumor virus (MMTV) is a retrovirus that expresses a superantigen shortly after infection of B cells. The superantigen first drives the polyclonal activation and proliferation of superantigen-reactive CD4+ T cells, which then induce the infected B cells to proliferate and differentiate. Part of the MMTV-induced B cell response leads to the production of Abs that are specific for the viral envelope protein gp52. Here we show that this Ab response has virus-neutralizing activity and confers protection against superinfection by other MMTV strains in vivo as soon as 4 to 7 days after infection. A protective Ab titer is maintained lifelong. Viral infection as well as the superantigen-induced T-B collaboration are required to generate this rapid and long lasting neutralizing Ab response. Polyclonal or superantigen-independent B cell activation, on the contrary, does not lead to detectable virus neutralization. The early onset of this superantigen-dependent neutralizing response suggests that viral envelope-specific B cells are selectively recruited to form part of the extrafollicular B cell response and are subsequently amplified and maintained by superantigen-reactive Th cells.

Behavioral phenotyping of glutathione-deficient mice: Relevance to schizophrenia and bipolar disorder.

Redox-dysregulation represents a common pathogenic mechanism in schizophrenia (SZ) and bipolar disorder (BP). It may in part arise from a genetically compromised synthesis of glutathione (GSH), the major cellular antioxidant and redox-regulator. Allelic variants of the genes coding for the rate-limiting GSH synthesizing enzyme glutamate-cysteine-ligase modifier (GCLM) and/or catalytic (GCLC) subunit have been associated with SZ and BP. Using mice knockout (KO) for GCLM we have previously shown that impaired GSH synthesis is associated with morphological, functional and neurochemical anomalies similar to those in patients. Here we asked whether GSH deficit is also associated with SZ- and BP-relevant behavioral and cognitive anomalies. Accordingly, we subjected young adult GCLM-wildtype (WT), heterozygous and KO males to a battery of standard tests. Compared to WT, GCLM-KO mice displayed hyperlocomotion in the open field and forced swim test but normal activity in the home cage, suggesting that hyperlocomotion was selective to environmental novelty and mildly stressful situations. While spatial working memory and latent inhibition remained unaffected, KO mice showed a potentiated hyperlocomotor response to an acute amphetamine injection, impaired sensorymotor gating in the form of prepulse inhibition and altered social behavior compared to WT. These anomalies resemble important aspects of both SZ and the manic component of BP. As such our data support the notion that redox-dysregulation due to GSH deficit is implicated in both disorders. Moreover, our data propose the GCLM-KO mouse as a valuable model to study the behavioral and cognitive consequences of redox dysregulation in the context of psychiatric disease.

Preparation with fasting and acipimox increases myocardial glucose uptake in mice during cardiac 18F-FDG microPET

Purpose: Cardiac 18F-FDG PET is considered as the gold standard to assess myocardial metabolism and infarct size. The myocardial demand for glucose can be influenced by fasting and/or following pharmacological preparation. In the rat, it has been previously shown that fasting combined with preconditioning with acipimox, a nicotinic acid derivate and lipidlowering agent, increased dramatically 18F-FDG uptake in the myocardium. Strategies aimed at reducing infarct scar are evaluated in a variety of mouse models. PET would particularly useful for assessing cardiac viability in the mouse. However, prior knowledge of the best preparation protocol is a prerequisite for accurate measurement of glucose uptake in mice. Therefore, we studied the effect of different protocols on 18F-FDG uptake in the mouse heart.Methods: Mice (n = 15) were separated into three treatment groups according to preconditioning and underwent a 18FDG PET scan. Group 1: No preconditioning (n = 3); Group 2: Overnight fasting (n = 8); and Group 3: Overnight fasting and acipimox (25mg/kg SC) (n = 4). MicroPET images were processed with PMOD to determine 18F-FDG mean standard uptake value (SUV) at 30 min for the whole left ventricle (LV) and for each region of the 17-segments AHA model. For comparisons, we used Mann-Whitney test and multilevel mixed-effects linear regression (Stata 11.0).Results: In total, 27 microPET were performed successfully in 15 animals. Overnight fasting led to a dramatic increase in LV-SUV compared to mice without preconditioning (8.6±0.7g/mL vs. 3.7±1.1g/mL, P<0.001). In addition, LV-SUV was slightly but not significantly higher in animals treated with acipimox compared to animals with overnight fasting alone (10.2±0.5 g/mL, P = 0.06). Fastening increased segmental SUV by 5.1±0.5g/mL as compared to free-feeding mice (from 3.7±0.8g/mL to 8.8±0.4g/mL, P<0.001); segmental-SUV also significantly increased after administration of acipimox (from 8.8±0.4g/mL to 10.1±0.4g/mL, P<0.001).Conclusion: Overnight fasting led to myocardial glucose deprivation and increases 18F-FDG myocardial uptake. Additional administration of acipimox enhances myocardial 18F-FDG uptake, at least at the segmental level. Thus, preconditioning with acipimox may provide better image quality that may help for assessing segmental myocardial metabolism.

Improved HIV-1 RNA quantitation by COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0 using a novel dual-target approach.

BACKGROUND: HIV-1 RNA viral load is a key parameter for reliable treatment monitoring of HIV-1 infection. Accurate HIV-1 RNA quantitation can be impaired by primer and probe sequence polymorphisms as a result of tremendous genetic diversity and ongoing evolution of HIV-1. A novel dual HIV-1 target amplification approach was realized in the quantitative COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0 (HIV-1 TaqMan test v2.0) to cope with the high genetic diversity of the virus. OBJECTIVES AND STUDY DESIGN: The performance of the new assay was evaluated for sensitivity, dynamic range, precision, subtype inclusivity, diagnostic and analytical specificity, interfering substances, and correlation with the COBAS AmpliPrep/COBAS TaqMan HIV-1 (HIV-1 TaqMan test v1.0) predecessor test in patients specimens. RESULTS: The new assay demonstrated a sensitivity of 20 copies/mL, a linear measuring range of 20-10,000,000 copies/mL, with a lower limit of quantitation of 20 copies/mL. HIV-1 Group M subtypes and HIV-1 Group O were quantified within +/-0.3 log(10) of the assigned titers. Specificity was 100% in 660 tested specimens, no cross reactivity was found for 15 pathogens nor any interference for endogenous substances or 29 drugs. Good comparability with the predecessor assay was demonstrated in 82 positive patient samples. In selected clinical samples 35/66 specimens were found underquantitated in the predecessor assay; all were quantitated correctly in the new assay. CONCLUSIONS: The dual-target approach for the HIV-1 TaqMan test v2.0 enables superior HIV-1 Group M subtype coverage including HIV-1 Group O detection. Correct quantitation of specimens underquantitated in the HIV-1 TaqMan test v1.0 test was demonstrated.

A new blood-based screening test for colorectal cancer: a pilot study

Background: Colorectal cancer (CRC) can be cured when diagnosed in its early or precancerous (adenoma) stages. Mostly due to poor compliance towards invasive screening procedures, detection rates for adenoma and early CRCs are still low. Available non-invasive screening tests have unfortunately low sensitivity and specificity performances. Therefore, there is a large unmet need calling for a cost-effective, reliable and non-invasive test to screen for early neoplastic and pre-neoplastic lesions. Objective: To develop a routine screening test based on a nucleic acids multi-gene assay performed on peripheral blood mononuclear cells (PBMCs) that can detect early CRCs and adenomas. Methods: 116 patients (mean age: 55 years; range: 18 to 74 years; female/male ration 0.98) were included in this pilot, nonblinded, colonoscopy-controlled study. Colonoscopy revealed 21 patients with CRC, 30 patients with adenoma bigger than 1 cm, 24 patients with inflammatory bowel disease (IBD) and 41 patients had no neoplastic or inflammatory lesions. Blood samples were taken from each patient the day of the colonoscopy and PBMCs were purified. Total RNA was extracted following standard procedures. Multiplex RT-qPCR was applied on 92 different candidate biomarkers. Different univariate and multivariate statistical methods were applied on these candidates, and among them, 57 biomarkers with significant p values (<0.01, Wilcoxon test) were selected, including ADAMTS1, MMP9, CXCL10, CXCR4, VEGFA and CDH1. Two distinct biomarker signatures are used to separate patients without neoplastic lesion from those with cancer (named COLOX 1 test), respectively from those with adenoma (named COLOX 2 test). Result: COLOX 1 and 2 tests have successfully separated patients without neoplastic lesion from those with CRC (sensitivity 70%, specificity 90%, AUC 0.88), respectively from those with adenoma bigger than 1cm (sensitivity 61%, specificity 80%, AUC 0.80). 6/24 patients in the IBD group have a positive COLOX 1 test. Conclusion: These two COLOX tests demonstrated an acceptable sensitivity and a high specificity to detect the presence of CRCs and adenomas bigger than 1 cm. The false positives COLOX 1 test in IBD patients could possibly be due to the chronic inflammatory state. A prospective, multicenter, pivotal study is underway in order to confirm these promising results in a larger cohort.

Dealing with clients' diversity in test situations: Client categorisations in psychologists' accounts of their practices

Reducing a test administration to standardised procedures reflects the test designers' standpoint. However, from the practitioners' standpoint, each client is unique. How do psychologists deal with both standardised test administration and clients' diversity? To answer this question, we interviewed 17 psychologists working in three public services for children and adolescents about their assessment practices. We analysed the numerous "client categorisations" they produced in their accounts. We found that they had shared perceptions about their clients' diversity, and reported various non-standard practices that complemented standardised test administration, but also differed from them or were even forbidden. They seem to experience a dilemma between: (a) prescribed and situated practices; (b) scientific and situated reliability; (c) commutative and distributive justice. For practitioners, dealing with clients' diversity this is a practical problem, halfway between a problem-solving task and a moral dilemma.

Passive knee-extension test to measure hamstring tightness: influence of gravity correction

CONTEXT: A passive knee-extension test has been shown to be a reliable method of assessing hamstring tightness, but this method does not take into account the potential effect of gravity on the tested leg. OBJECTIVE: To compare an original passive knee-extension test with 2 adapted methods including gravity's effect on the lower leg. DESIGN: Repeated measures. SETTING: Laboratory. PARTICIPANTS: 20 young track and field athletes (16.6 ± 1.6 y, 177.6 ± 9.2 cm, 75.9 ± 24.8 kg). INTERVENTION: Each subject was tested in a randomized order with 3 different methods: In the original one (M1), passive knee angle was measured with a standard force of 68.7 N (7 kg) applied proximal to the lateral malleolus. The second (M2) and third (M3) methods took into account the relative lower-leg weight (measured respectively by handheld dynamometer and anthropometrical table) to individualize the force applied to assess passive knee angle. MAIN OUTCOME MEASURES: Passive knee angles measured with video-analysis software. RESULTS: No difference in mean individualized applied force was found between M2 and M3, so the authors assessed passive knee angle only with M2. The mean knee angle was different between M1 and M2 (68.8 ± 12.4 vs 73.1 ± 10.6, P < .001). Knee angles in M1 and M2 were correlated (r = .93, P < .001). CONCLUSIONS: Differences in knee angle were found between the original passive knee-extension test and a method with gravity correction. M2 is an improved version of the original method (M1) since it minimizes the effect of gravity. Therefore, we recommend using it rather than M1.

Fluorine-19 magnetic resonance angiography of the mouse.

PURPOSE: To implement and characterize a fluorine-19 ((19)F) magnetic resonance imaging (MRI) technique and to test the hypothesis that the (19)F MRI signal in steady state after intravenous injection of a perfluoro-15-crown-5 ether (PCE) emulsion may be exploited for angiography in a pre-clinical in vivo animal study. MATERIALS AND METHODS: In vitro at 9.4T, the detection limit of the PCE emulsion at a scan time of 10 min/slice was determined, after which the T(1) and T(2) of PCE in venous blood were measured. Permission from the local animal use committee was obtained for all animal experiments. 12 µl/g of PCE emulsion was intravenously injected in 11 mice. Gradient echo (1)H and (19)F images were obtained at identical anatomical levels. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were determined for 33 vessels in both the (19)F and (1)H images, which was followed by vessel tracking to determine the vessel conspicuity for both modalities. RESULTS: In vitro, the detection limit was ∼400 µM, while the (19)F T(1) and T(2) were 1350±40 and 25±2 ms. The (19)F MR angiograms selectively visualized the vasculature (and the liver parenchyma over time) while precisely coregistering with the (1)H images. Due to the lower SNR of (19)F compared to (1)H (17±8 vs. 83±49, p<0.001), the (19)F CNR was also lower at 15±8 vs. 52±35 (p<0.001). Vessel tracking demonstrated a significantly higher vessel sharpness in the (19)F images (66±11 vs. 56±12, p = 0.002). CONCLUSION: (19)F magnetic resonance angiography of intravenously administered perfluorocarbon emulsions is feasible for a selective and exclusive visualization of the vasculature in vivo.

Assessing the Glaucoma Quality of Life-15 (GCL-15) Questionnaire, Goldmann Tonometry and Moorfields Motion Displacement Test in Glaucoma Case Finding

Purpose: To compare the performance Glaucoma Quality of Life-15 (GQL-15) Questionnaire, intraocular pressure measurement (IOP Goldmann tonometry) and a measure of visual field loss using Moorfields Motion Displacement Test (MDT) in detecting glaucomatous eyes from a self referred population. Methods: The GQL-15 has been suggested to correlate with visual disability and psychophysical measures of visual function in glaucoma patients. The Moorfields MDT is a multi location perimetry test with 32 white line stimuli presented on a grey background on a standard laptop computer. Each stimulus is displaced between computer frames to give the illusion of "apparent motion". Participants (N=312, 90% older than 45 years; 20.5% family history of glaucoma) self referred to an advertised World Glaucoma Day (March 2009) Jules Gonin Eye Hospital, Lausanne Switzerland. Participants underwent a clinical exam (IOP, slit lamp, angle and disc examination by a general ophthalmologist), 90% completed a GQL-15 questionnaire and over 50% completed a MDT test in both eyes. Those who were classified as abnormal on one or more of the following (IOP >21 mmHg/ GQL-15 score >20/ MDT score >2/ clinical exam) underwent a follow up clinical examination by a glaucoma specialist including imaging and threshold perimetry. After the second examination subjects were classified as "healthy"(H), "glaucoma suspect" (GS) (ocular hypertension and/or suspicious disc, angle closure with SD) or "glaucomatous" (G). Results: One hundred and ten subjects completed all 4 initial examinations; of these 69 were referred to complete the 2nd examination and were classified as; 8 G, 24 GS, and 37 H. MDT detected 7/8 G, and 7/24 GS, with false referral rate of 3.8%. IOP detected 2/8 G and 8/24 GS, with false referral rate of 8.9%. GQL-15 detected 4/8 G, 16/24 GS with a false referral rate of 42%. Conclusions: In this sample of participants attending a self referral glaucoma detection event, the MDT performed significantly better than the GQL-15 and IOP in discriminating glaucomatous patients from healthy subjects. Further studies are required to assess the potential of the MDT as a glaucoma screening tool.