Functional MRI evaluation of liver tumour response after radiofrequency: short- and mid-term evolution of diffusion parameters

Purpose: To evaluate the short- and mid-term evolutions of the apparent diffusion coefficient of lesions treated with RF, in order to determine if the ADC can be used as a marker of tumour response. Methods and Materials: Twenty patients were treated for a liver malignancy with RF and were examined on a 1.5 T/3.0 T machine with T2, gadolinium-enhanced T1 and diffusion sequences: before treatment (< 1 month), just after treatment (< 1 month) and midterm (3-6 months). The ADC was measured in the whole lesion and in the area with the most restricted diffusion (MRDA). The ROI size was also measured on the diffusion map. The Pearson/ANOVA tests were used. Results: All patients were successfully treated with complete disappearance of CE. The lesional size on T2 showed a negative evolution in time (p < 0.002). The ADC in the whole lesion showed a bell-shaped evolution (increasing just after RF, then decreasing, p = 0.02). The ROI size on the diffusion map followed a similar course (p = 0.01). For the MRDA, such evolutions were also found, but they were not significant. There was a negative correlation between CE and the ADC (p < 0.02) and between the lesional size on T2 and ADC (p = 0.03) in the whole lesion. There were also positive correlations between the ROI size and ADC (p = 0.0008) and between CE and the size on T2 (p = 0.0002). The ADC in MRDA showed some non-significant correlations with other variables. Conclusion: The lesions successfully treated with RF have a clear and predictable evolution in terms of T2 size, CE and ADC.

Three-dimensional ordered-subset expectation maximization iterative protocol for evaluation of left ventricular volumes and function by quantitative gated SPECT: a dynamic phantom study.

The purposes of this study were to characterize the performance of a 3-dimensional (3D) ordered-subset expectation maximization (OSEM) algorithm in the quantification of left ventricular (LV) function with (99m)Tc-labeled agent gated SPECT (G-SPECT), the QGS program, and a beating-heart phantom and to optimize the reconstruction parameters for clinical applications. METHODS: A G-SPECT image of a dynamic heart phantom simulating the beating left ventricle was acquired. The exact volumes of the phantom were known and were as follows: end-diastolic volume (EDV) of 112 mL, end-systolic volume (ESV) of 37 mL, and stroke volume (SV) of 75 mL; these volumes produced an LV ejection fraction (LVEF) of 67%. Tomographic reconstructions were obtained after 10-20 iterations (I) with 4, 8, and 16 subsets (S) at full width at half maximum (FWHM) gaussian postprocessing filter cutoff values of 8-15 mm. The QGS program was used for quantitative measurements. RESULTS: Measured values ranged from 72 to 92 mL for EDV, from 18 to 32 mL for ESV, and from 54 to 63 mL for SV, and the calculated LVEF ranged from 65% to 76%. Overall, the combination of 10 I, 8 S, and a cutoff filter value of 10 mm produced the most accurate results. The plot of the measures with respect to the expectation maximization-equivalent iterations (I x S product) revealed a bell-shaped curve for the LV volumes and a reverse distribution for the LVEF, with the best results in the intermediate range. In particular, FWHM cutoff values exceeding 10 mm affected the estimation of the LV volumes. CONCLUSION: The QGS program is able to correctly calculate the LVEF when used in association with an optimized 3D OSEM algorithm (8 S, 10 I, and FWHM of 10 mm) but underestimates the LV volumes. However, various combinations of technical parameters, including a limited range of I and S (80-160 expectation maximization-equivalent iterations) and low cutoff values (< or =10 mm) for the gaussian postprocessing filter, produced results with similar accuracies and without clinically relevant differences in the LV volumes and the estimated LVEF.

Glucocorticoid-induced MIF expression by human CEM T cells.

Macrophage migration inhibitory factor (MIF) is an upstream activator of the immune response that counter-regulates the immunosuppressive effects of glucocorticoids. While MIF is released by cells in response to diverse microbial and invasive stimuli, evidence that glucocorticoids in low concentrations also induce MIF secretion suggests an additional regulatory relationship between these mediators. We investigated the expression of MIF from the human CEM T cell line, which exists in two well-characterized, glucocorticoid-sensitive (CEM-C7) and glucocorticoid-resistant (CEM-C1) variant clones. Dexamethasone in low concentrations induced MIF secretion from CEM-C7 but not CEM-C1 T cells by a bell-shaped dose response that was similar to that reported previously for the release of MIF by monocytes/macrophages. Glucocorticoid stimulation of CEM-C7 T cells was accompanied by an MIF transcriptional response, which by promoter analysis was found to involve the GRE and ATF/CRE transcription factor binding sites. These data support a glucocorticoid-mediated MIF secretion response by T cells that may contribute to the regulation of the adaptive immune response.

Indirect costs of parasitism are shaped by variation in the type of immune challenge and food availability

Parasites can inflict indirect fitness costs to their hosts by eliciting costly immune responses. These costs depend on the type and amount of immunostimulants presented to the host immune system but also on the amount of resources available to fuel host immune responses. Here, we investigated how the relative costs of two different types of immune challenge are modulated by variation in food availability. We injected nestling tawny owls (Strix aluco) with either 10 mu g of phytohaemagglutinin (PHA) or 20 mu g of lipopolysaccharide (LPS), and subsequently raised them under two different food regimes (food-restricted vs. ad libitum). After controlling for food consumption, we found that LPS-injected nestlings lost more body mass than PHA-injected ones only when food-restricted. We also found that body mass gain of owlets fed ad libitum decreased with the intensity of the skin swelling response against LPS, but not PHA. These experimental and correlative results suggest that nestling tawny owls suffered greater immune costs when treated with LPS than PHA, and that variation in the costs of two different types of immune challenge can be exacerbated under conditions of low food availability. Our study highlights the importance of taking into consideration the interplay between host immunity and nutrition in the study of indirect costs of parasitism.

Biocompatibility of an x-shaped zirconium implant in deep sclerectomy in rabbits.

BACKGROUND: The aim of this study was to evaluate the mid-term biocompatibility of a new x-shaped implant made of zirconium in an animal model of glaucoma surgery. METHODS: Preoperatively, ultrasound biomicroscopy (UBM), intraocular pressure (IOP) and outflow facility (OF) data were acquired. Upon surgery, one eye was chosen randomly to receive an implant, while the other received none. Ten rabbits went through a 1-, 2-, 3-, 4- and 6-month follow-up. IOP was measured regularly, UBM performed at 1, 3 and 6 months after surgery. At the end of the follow-up, OF was again measured. Histology sections were analyzed. RESULTS: For both groups IOP control was satisfactory, while OF initially increased at month 1 to resume preoperative values thereafter. Eyes with implants had larger filtration blebs which decreased faster than in eyes without the implant. Drainage vessel density, inflammatory cell number and fibrosis were higher in tissues near the implant. CONCLUSIONS: The zirconium implant initially promoted the positive effects of the surgery (IOP control, OF increase). Nevertheless, after several months, foreign body reactions and fibrosis had occurred on some implants that restrained the early benefit of such a procedure. Modifications of the zirconium implant geometry could enhance the overall success rate.

On dome-shaped norms of reaction for size-to-age at maturity in fishes

The optimal size-to-age at maturity depends on growth and mortality rates, which vary with environment. Therefore, organisms in spatially or temporaly changing environments should develop adaptative phenotypic plasticity for this trait. Experimental work by Alm (1959) on several fish species shows a dome-shape norm of reaction for size-to-age at maturity: size at maturity is smaller in both fast-growing and slow-growing fishes, than it is in fish with a medium growth rate. Using computer simulations, we show that such a dome-shaped norm of reaction is optimal when assuming a finite life span and a negative relationship between production and survival rates. This latter assumption is supported by empirical data, as well as by physiological and emographic arguments.

Use of combined suspension laryngoscopy, flexible bronchoscopy and high frequency jet ventilation for Y-shaped airway stents delivery

La trachée et les bronches proximales sont de fins conduits subtils, ingénieusement structurés par une partie cartilagineuse antérieure résistante aux variations de pression et une partie membraneuse postérieure souple. Par leurs faibles volumes (espace mort) ils délivrent un grand pourcentage de l'air inspiré aux voies distales, puis au parenchyme pulmonaire, permettant les échanges de gaz. Cette belle harmonie respiratoire peut être rapidement mise à mal dès qu'un processus atteint ces voies respiratoires proximales, soit en les comprimant, processus sténosant, soit en affaiblissant leur structure, trachéo-bronchomalacie, soit en ouvrant leur paroi sur les structures médiastinales, fistule trachéo/broncho-médiastinales, pleurales ou autres. Le pronostic vital est alors rapidement engagé au vu de l'absolue nécessité du bon fonctionnement de ces fins conduits, une petite diminution du calibre de leurs fines lumières provoquant une baisse importante de leurs surfaces. Dans ces situations à haut potentiel de complication majeure les interventions endoscopiques pour restaurer l'intégrité de ces conduits sont alors fort risquées, et il est primordial de pouvoir les effectuer dans un cadre sécurisé au maximum. La réalisation de ces gestes par la technique décrite dans notre article « Use of combined suspension laryngoscopy, flexible bronchoscopy and high frequency jet ventilation forY-shaped airway stents delivery" permet la sécurité nécessaire à ces situations instable, en effet -la laryngoscopie en suspension expose les voies proximales en offrant un accès le plus large possible à l'arbre trachéobronchique ce qui permet l insertion de multiples instruments parfois volumineux, -la Jet ventilation assure une oxygénation et une ventilation adéquate par un fin cathéter placé soit dans le poumon sain, soit en distalité de la lésion -la bronchoscopie souple, passant au travers d'endroits exigus et courbes permet le déploiement sous vision direct, au millimètre près, de divers dispositifs. Cette association remplace avantageusement la technique traditionnelle qui insère les stents à l'aveugle, et en apnée, ce qui représente de haut risque de mauvais positionnement des stents avec des conséquences immédiates sur l'oxygénation et la ventilation souvent déjà bien altérées. Perspective et conclusion : cette technique est utile pour l'insertion des stents en Y, centraux, comme décrit dans notre article, et les indications peuvent être étendues aux stents distaux pour lesquels l'accès n'est parfois pas aisé avec le bronchoscope rigide, et pour d'autres interventions endoscopiques, laser, cryothérapie, radiofréquence ou l'insertion de nouveaux dispositifs.

Resolution of foveal detachment in dome-shaped macula after treatment by spironolactone: report of two cases and mini-review of the literature.

Dome-shaped macula (DSM) was recently described in myopic patients as a convex protrusion of the macula within a posterior pole staphyloma. The pathogenesis of DSM and the development of associated serous foveal detachment (SFD) remain unclear. The obstruction of choroidal outflow and compressive changes of choroidal capillaries have been proposed as causative factors. In this paper, we report two cases of patients with chronic SFD associated with DSM treated with oral spironolactone. After treatment, there was a complete resolution of SFD in both patients. To the best of our knowledge, this is the first report of successful treatment of SFD in DSM by a mineralocorticoid receptor antagonist.

In vivo study comparing an X-shaped polymethylmethacrylate and a cylindrical collagen implant for deep sclerectomy.

Background:  Study in vivo characteristics of a polymethylmethacrylate (PMMA) implant compared to the standard cylindrical collagen implant for deep sclerectomy (DS). Design:  Six-month comparative study. Samples:  Twenty eyes of ten rabbits. Methods:  Eyes were randomized to have DS with PMMA implant in one eye and collagen implant in the opposite eye. The growth of the new subconjunctival drainage vessels was assessed by combined fluorescein and indocyanin green anterior segment angiography; intrascleral and subconjunctival blebs were imaged by ultrasound biomicroscopy (UBM). At six months, outflow facility (C) was measured by anterior chamber perfusion and portions of one side of the DS were compared to portions on the 180° opposite side and native sclera on histology. Results:  The mean IOP preoperatively and at one, four, twelve, and twenty-four weeks was comparable in both groups (P > 0.1). UBM showed a statistically insignificant quicker regression of the subconjunctival bleb as well as a durable intrascleral lake in the PMMA group (P > 0.05). New drainage vessels were initially observed one month after surgery; they were more numerous in the PMMA group on angiographic and histological findings at 6 months (P < 0.05). The mean C increased significantly after surgery compared to preoperative values (P < 0.05) and no difference was observed between the implants (0.24 ± 0.06 µl/min/mmHg [PMMA] and 0.23 ± 0.07 µl/min/mmHg [collagen implant]) (P = 0.39). Conclusions:  Deep sclerectomy performed with PMMA or collagen implants showed similar IOP lowering effects, outflow facility increase, and degree of inflammatory reaction.

How Answers on Political Attitudes are Shaped by Interviewers: Evidence from a Panel Survey

We analyze whether the interviewers' political opinions have an influence on those of the respondents. The research uses data from a panel survey in which interviewers are randomly assigned to respondents. The results show that the respondents express significantly similar opinions to those of the interviewers in all questions considered. Multilevel models show that more educated respondents are affected to a slightly higher extent and that the interviewer's experience is also a factor. There is no difference between different respondent subgroups or when both interviewers and respondents share the same socio-demographic characteristics. While there is no evidence for respondents wanting to please the interviewers, the hypothesis of socially desirable behavior can indeed be confirmed.

A 2D/3D image analysis system to track fluorescently labeled structures in rod-shaped cells: application to measure spindle pole asymmetry during mitosis.

BACKGROUND: The yeast Schizosaccharomyces pombe is frequently used as a model for studying the cell cycle. The cells are rod-shaped and divide by medial fission. The process of cell division, or cytokinesis, is controlled by a network of signaling proteins called the Septation Initiation Network (SIN); SIN proteins associate with the SPBs during nuclear division (mitosis). Some SIN proteins associate with both SPBs early in mitosis, and then display strongly asymmetric signal intensity at the SPBs in late mitosis, just before cytokinesis. This asymmetry is thought to be important for correct regulation of SIN signaling, and coordination of cytokinesis and mitosis. In order to study the dynamics of organelles or large protein complexes such as the spindle pole body (SPB), which have been labeled with a fluorescent protein tag in living cells, a number of the image analysis problems must be solved; the cell outline must be detected automatically, and the position and signal intensity associated with the structures of interest within the cell must be determined. RESULTS: We present a new 2D and 3D image analysis system that permits versatile and robust analysis of motile, fluorescently labeled structures in rod-shaped cells. We have designed an image analysis system that we have implemented as a user-friendly software package allowing the fast and robust image-analysis of large numbers of rod-shaped cells. We have developed new robust algorithms, which we combined with existing methodologies to facilitate fast and accurate analysis. Our software permits the detection and segmentation of rod-shaped cells in either static or dynamic (i.e. time lapse) multi-channel images. It enables tracking of two structures (for example SPBs) in two different image channels. For 2D or 3D static images, the locations of the structures are identified, and then intensity values are extracted together with several quantitative parameters, such as length, width, cell orientation, background fluorescence and the distance between the structures of interest. Furthermore, two kinds of kymographs of the tracked structures can be established, one representing the migration with respect to their relative position, the other representing their individual trajectories inside the cell. This software package, called "RodCellJ", allowed us to analyze a large number of S. pombe cells to understand the rules that govern SIN protein asymmetry. CONCLUSIONS: "RodCell" is freely available to the community as a package of several ImageJ plugins to simultaneously analyze the behavior of a large number of rod-shaped cells in an extensive manner. The integration of different image-processing techniques in a single package, as well as the development of novel algorithms does not only allow to speed up the analysis with respect to the usage of existing tools, but also accounts for higher accuracy. Its utility was demonstrated on both 2D and 3D static and dynamic images to study the septation initiation network of the yeast Schizosaccharomyces pombe. More generally, it can be used in any kind of biological context where fluorescent-protein labeled structures need to be analyzed in rod-shaped cells. AVAILABILITY: RodCellJ is freely available under http://bigwww.epfl.ch/algorithms.html, (after acceptance of the publication).

In vivo study comparing an X-shaped polymethylmethacrylate and a cylindrical collagen implant for deep sclerectomy

Il s'agit de comparer in vivo la sécurité et l'efficacité d'un implant en polyméthylméthacrylate (PMMA) avec un implant standard en collagène dans la sclérectomie profonde (SP) sur une durée de six mois. La population étudiée comprend vingt lapins, chaque lapin étant randomisé pour une SP avec implant en PMMA dans un oeil et implant de collagène dans l'autre oeil. Plusieurs éléments ont été pris en compte dans la comparaison : - la mesure de la pression intraoculaire - l'évolution de l'espace de drainage intrascléral et de la bulle de filtration sous-conjonctivale, suivie par ultrasonographic biomicroscopique (UBM) - la croissance de nouveaux vaisseaux de drainage sous-conjonctivaux, croissance quantifiée par angiographie du segment antérieur à la fluorescéine combinée au vert d'indocyanine - la facilité à l'écoulement de l'humeur aqueuse (C), mesurée à six mois par cannulation-perfusion de la chambre antérieur - la sclère au site de SP, histologiquement comparée à la sclère native opposée à 180°, également à six mois La pression intraoculaire moyenne préopératoire à une, quatre, douze et 24 semaines postopératoires est comparable dans les deux groupes (P>0.1). L'UBM montre une régression légèrement plus rapide (statistiquement non significative) de la bulle de filtration sous-conjonctivale et la persistance d'un espace de drainage intrascléral dans le groupe PMMA (P>0.05). De nouveaux vaisseaux de drainage sont observés à un mois de la chirurgie ; à six mois, ces vaisseaux sont plus nombreux dans le groupe PMMA, tant sur l'analyse angiographique que sur l'analyse histologique (P>0.05). La facilité moyenne à l'écoulement de l'humeur aqueuse est significativement plus élevées à six mois dans les deux groupes par rapport aux valeurs préopératoires (P>0.05), sans qu'il n'y ait de différence entre les deux implants (0.24 ± 0.06 μΙ/min/mmHg [PMMA] et 0.23 ± 0.07 μΙ/min/mmHg [implant en collagène]) (Ρ = 0.39). Cette étude a pu démontrer que la sclérectomie profonde avec implant en collagène ou en PMMA donne des résultats similaires en terme de diminution de l'IOP et d'augmentation de la facilité à l'écoulement de l'humeur aqueuse, sans différence sur le plan des réactions inflammatoires post-intervention.

Evidence for tuning adipocytes ICER levels for obesity care.

Abnormal adipokine production, along with defective uptake and metabolism of glucose within adipocytes, contributes to insulin resistance and altered glucose homeostasis. Recent research has highlighted one of the mechanisms that accounts for impaired production of adiponectin (ADIPOQ) and adipocyte glucose uptake in obesity. In adipocytes of human obese subjects and mice fed with a high fat diet, the level of the inducible cAMP early repressor (ICER) is diminished. Reduction of ICER elevates the cAMP response element binding protein (CREB) activity, which in turn increases the repressor activating transcription factor 3. In fine, the cascade triggers reduction in the ADIPOQ and GLUT4 levels, which ultimately hampers insulin-mediated glucose uptake. The c-Jun N-terminal kinase (JNK) interacting-protein 1, also called islet brain 1 (IB1), is a target of CREB/ICER that promotes JNK-mediated insulin resistance in adipocytes. A rise in IB1 and c-Jun levels accompanies the drop of ICER in white adipose tissues of obese mice when compared with mice fed with a chow diet. Other than the expression of ADIPOQ and glucose transport, decline in ICER expression might impact insulin signaling. Impairment of ICER is a critical issue that will need major consideration in future therapeutic purposes.

An Automatic Approach for Learning and Tuning Gaussian Interval Type-2 Fuzzy Membership Functions Applied to Lung CAD Classification System

The potential of type-2 fuzzy sets for managing high levels of uncertainty in the subjective knowledge of experts or of numerical information has focused on control and pattern classification systems in recent years. One of the main challenges in designing a type-2 fuzzy logic system is how to estimate the parameters of type-2 fuzzy membership function (T2MF) and the Footprint of Uncertainty (FOU) from imperfect and noisy datasets. This paper presents an automatic approach for learning and tuning Gaussian interval type-2 membership functions (IT2MFs) with application to multi-dimensional pattern classification problems. T2MFs and their FOUs are tuned according to the uncertainties in the training dataset by a combination of genetic algorithm (GA) and crossvalidation techniques. In our GA-based approach, the structure of the chromosome has fewer genes than other GA methods and chromosome initialization is more precise. The proposed approach addresses the application of the interval type-2 fuzzy logic system (IT2FLS) for the problem of nodule classification in a lung Computer Aided Detection (CAD) system. The designed IT2FLS is compared with its type-1 fuzzy logic system (T1FLS) counterpart. The results demonstrate that the IT2FLS outperforms the T1FLS by more than 30% in terms of classification accuracy.

A U-shaped association between intensity of Internet use and adolescent health.

OBJECTIVE: To examine the relationship between different Internet-use intensities and adolescent mental and somatic health. METHODS: Data were drawn from the 2002 Swiss Multicenter Adolescent Survey on Health, a nationally representative survey of adolescents aged 16 to 20 years in post-mandatory school. From a self-administered anonymous questionnaire, 3906 adolescent boys and 3305 girls were categorized into 4 groups according to their intensity of Internet use: heavy Internet users (HIUs; >2 hours/day), regular Internet users (RIUs; several days per week and <= 2 hours/day), occasional users (<= 1 hour/week), and non-Internet users (NIUs; no use in the previous month). Health factors examined were perceived health, depression, overweight, headaches and back pain, and insufficient sleep. RESULTS: In controlled multivariate analysis, using RIUs as a reference, HIUs of both genders were more likely to report higher depressive scores, whereas only male users were found at increased risk of overweight and female users at increased risk of insufficient sleep. Male NIUs and female NIUs and occasional users also were found at increased risk of higher depressive scores. Back-pain complaints were found predominantly among male NIUs. CONCLUSIONS: Our study provides evidence of a U-shaped relationship between intensity of Internet use and poorer mental health of adolescents. In addition, HIUs were confirmed at increased risk for somatic health problems. Thus, health professionals should be on the alert when caring for adolescents who report either heavy Internet use or very little/none. Also, they should consider regular Internet use as a normative behavior without major health consequence. Pediatrics 2011;127:e330-e335