Comment la sérologie peut-elle aider à l'établissement du diagnostic des parasites [How can serology contribute to the diagnosis of parasitic diseases?].

From a technical standpoint the most widely used tests for serology include the ELISA (enzyme linked immunosorbent assay), the IFA (indirect fluorescence assay), and the immunoblot. ELISA tests are widely used as screening assays since they harbor a high sensitivity. The main pitfall of serologies is the frequency of cross-reactions, especially between the different helminths. This is why positive results should be confirmed by a second test method with a higher specificity. Results need also to be put in the perspective of the patient history, clinical signs and laboratory findings. Serological tests are most appropriate when the parasite cannot be documented by direct examination (by eye or under the microscope) and during the pre-patent period. Serologies for parasites are also useful when an unexplained eosinophilia is present.

Plasmid electrotransfer of eye ciliary muscle: principles and therapeutic efficacy using hTNF-alpha soluble receptor in uveitis.

Due to its small size and particular isolating barriers, the eye is an ideal target for local therapy. Recombinant protein ocular delivery requires invasive and painful repeated injections. Alternatively, a transfected tissue might be used as a local producer of transgene-encoded therapeutic protein. We have developed a nondamaging electrically mediated plasmid delivery technique (electrotransfer) targeted to the ciliary muscle, which is used as a reservoir tissue for the long-lasting expression and secretion of therapeutic proteins. High and long-lasting reporter gene expression was observed, which was restricted to the ciliary muscle. Chimeric TNF-alpha soluble receptor (hTNFR-Is) electrotransfer led to elevated protein secretion in aqueous humor and to drastic inhibition of clinical and histological inflammation scores in rats with endotoxin-induced uveitis. No hTNFR-Is was detected in the serum, demonstrating the local delivery of proteins using this method. Plasmid electrotransfer to the ciliary muscle, as performed in this study, did not induce any ocular pathology or structural damage. Local and sustained therapeutic protein production through ciliary muscle electrotransfer is a promising alternative to repeated intraocular protein administration for a large number of inflammatory, degenerative, or angiogenic diseases.

Transscleral Coulomb-controlled iontophoresis of methylprednisolone into the rabbit eye: influence of duration of treatment, current intensity and drug concentration on ocular tissue and fluid levels.

The major problems associated with the use of corticosteroids for the treatment of ocular diseases are their poor intraocular penetration to the posterior segment when administered locally and their secondary side effects when given systemically. To circumvent these problems more efficient methods and techniques of local delivery are being developed. The purposes of this study were: (1) to investigate the pharmacokinetics of intraocular penetration of hemisuccinate methyl prednisolone (HMP) after its delivery using the transscleral Coulomb controlled iontophoresis (CCI) system applied to the eye or after intravenous (i.v.) injection in the rabbit, (2) to test the safety of the CCI system for the treated eyes and (3) to compare the pharmacokinetic profiles of HMP intraocular distribution after CCI delivery to i.v. injection. For each parameter evaluated, six rabbit eyes were used. For the CCI system, two concentrations of HMP (62.5 and 150mg ml(-1)), various intensities of current and duration of treatment were analyzed. In rabbits serving as controls the HMP was infused in the CCI device but without applied electric current. For the i.v. delivery, HMP at 10mg kg(-1)as a 62.5mg ml(-1)solution was used. The rabbits were observed clinically for evidence of ocular toxicity. At various time points after the administration of drug, rabbits were killed and intraocular fluids and tissues were sampled for methylprednisolone (MP) concentrations by high pressure liquid chromatography (HPLC). Histology examinations were performed on six eyes of each group. Among groups that received CCI, the concentrations of MP increased in all ocular tissues and fluids in relation to the intensities of current used (0.4, 1.0 and 2.0mA/0.5cm(2)) and its duration (4 and 10min). Sustained and highest levels of MP were achieved in the choroid and the retina of rabbit eyes treated with the highest current and 10min duration of CCI. No clinical toxicity or histological lesions were observed following CCI. Negligible amounts of MP were found in ocular tissues in the CCI control group without application of current. Compared to i.v. administration, CCI achieved higher and more sustained tissue concentrations with negligible systemic absorption. These data demonstrate that high levels of MP can be safely achieved in intraocular tissues and fluids of the rabbit eye, using CCI. With this system, intraocular tissues levels of MP are higher than those achieved after i.v. injection. Furthermore, if needed, the drug levels achieved with CCI can be modulated as a function of current intensity and duration of treatment. CCI could therefore be used as an alternative method for the delivery of high levels of MP to the intraocular tissues of both the anterior and posterior segments.

Vectorisation intra-oculaire [Drug delivery to target the posterior segment of the eye].

Retinal diseases are nowadays the most common causes of vision threatening in developed countries. Therapeutic advances in this field are hindered by the difficulty to deliver drugs to the posterior segment of the eye. Due to anatomical barriers, the ocular biodisponibility of systemically administered drugs remains poor, and topical instillation is not adequate to achieve therapeutic concentrations of drugs in the back of the eye. Ocular drug delivery has thus become one of the main challenges of modern ophthalmology. A multidisciplinary research is being conducted worldwide including pharmacology, biomaterials, ophthalmology, pharmaceutics, and biology. New promising fields have been developed such as implantable or injectable slow release intravitreal devices and degradable polymers, dispersed polymeric systems for intraocular drug delivery, and transscleral delivery devices such as iontophoresis, osmotic pumps or intra-scleraly implantable materials. The first clinical applications emerging from this research are now taking place, opening new avenues for the treatment of retinal diseases.

A novel cyclosporin a aqueous formulation for dry eye treatment: in vitro and in vivo evaluation.

PURPOSE: The aim of the present study was the in vitro and in vivo evaluation of a novel aqueous formulation based on polymeric micelles for the topical delivery of cyclosporine A for dry eye treatment. METHODS: In vitro experiments were carried out on primary rabbit corneal cells, which were characterized by immunocytochemistry using fluorescein-labeled lectin I/isolectin B4 for the endothelial cells and mouse monoclonal antibody to cytokeratin 3+12 for the epithelial ones. Living cells were incubated for 1 hour or 24 hours with a fluorescently labeled micelle formulation and analyzed by fluorescence microscopy. In vivo evaluations were done by Schirmer test, osmolarity measurement, CyA kinetics in tears, and CyA ocular distribution after topical instillation. A 0.05% CyA micelle formulation was compared to a marketed emulsion (Restasis). RESULTS: The in vitro experiments showed the internalization of micelles in the living cells. The Schirmer test and osmolarity measurements demonstrated that micelles did not alter the ocular surface properties. The evaluation of the tear fluid gave similar CyA kinetics values: AUC = 2339 ± 1032 min*μg/mL and 2321 ± 881.63; Cmax = 478 ± 111 μg/mL and 451 ± 74; half-life = 36 ± 9 min and 28 ± 9 for the micelle formulation and Restasis, respectively. The ocular distribution investigation revealed that the novel formulation delivered 1540 ± 400 ng CyA/g tissue to the cornea. CONCLUSIONS: The micelle formulation delivered active CyA into the cornea without evident negative influence on the ocular surface properties. This formulation could be applied for immune-related ocular surface diseases.

Evaluation of a novel biomaterial in the suprachoroidal space of the rabbit eye.

PURPOSE: Drug delivery to treat diseases of the posterior segment of the eye, such as choroidal neovascularization and its complications, is hampered by poor intraocular penetration and rapid elimination of the drug from the eye. The purpose of this study was to investigate the feasibility and tolerance of suprachoroidal injections of poly(ortho ester) (POE), a bioerodible and biocompatible polymer, as a biomaterial potentially useful for development of sustained drug delivery systems. METHODS: After tunnelization of the sclera, different formulations based on POE were injected (100 microL) into the suprachoroidal space of pigmented rabbits and compared with 1% sodium hyaluronate. Follow-up consisted of fundus observations, echography, fluorescein angiography, and histologic analysis over 3 weeks. RESULTS: After injection, POE spread in the suprachoroidal space at the posterior pole. It was well tolerated and progressively disappeared from the site of injection without sequelae. No bleeding or retinal detachment occurred. Echographic pictures showed that the material was present in the suprachoroidal space for 3 weeks. Angiography revealed minor pigment irregularities at the site of injection, but no retinal edema or necrosis. Histology showed that POE was well tolerated in the choroid. CONCLUSIONS: POE suprachoroidal injections, an easy, controllable, and reproducible procedure, were well tolerated in the rabbit eye. POE appears to be a promising biomaterial to deliver drugs focally to the choroid and the retina.

Automatic Segmentation of the Eye in 3D Magnetic Resonance Imaging: A Novel Statistical Shape Model for Treatment Planning of Retinoblastoma.

PURPOSE: Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes. METHODS AND MATERIALS: Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error. RESULTS: We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye. CONCLUSION: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor.

Eye-tracking of nodule detection in lung CT volumetric data.

PURPOSE: Signal detection on 3D medical images depends on many factors, such as foveal and peripheral vision, the type of signal, and background complexity, and the speed at which the frames are displayed. In this paper, the authors focus on the speed with which radiologists and naïve observers search through medical images. Prior to the study, the authors asked the radiologists to estimate the speed at which they scrolled through CT sets. They gave a subjective estimate of 5 frames per second (fps). The aim of this paper is to measure and analyze the speed with which humans scroll through image stacks, showing a method to visually display the behavior of observers as the search is made as well as measuring the accuracy of the decisions. This information will be useful in the development of model observers, mathematical algorithms that can be used to evaluate diagnostic imaging systems. METHODS: The authors performed a series of 3D 4-alternative forced-choice lung nodule detection tasks on volumetric stacks of chest CT images iteratively reconstructed in lung algorithm. The strategy used by three radiologists and three naïve observers was assessed using an eye-tracker in order to establish where their gaze was fixed during the experiment and to verify that when a decision was made, a correct answer was not due only to chance. In a first set of experiments, the observers were restricted to read the images at three fixed speeds of image scrolling and were allowed to see each alternative once. In the second set of experiments, the subjects were allowed to scroll through the image stacks at will with no time or gaze limits. In both static-speed and free-scrolling conditions, the four image stacks were displayed simultaneously. All trials were shown at two different image contrasts. RESULTS: The authors were able to determine a histogram of scrolling speeds in frames per second. The scrolling speed of the naïve observers and the radiologists at the moment the signal was detected was measured at 25-30 fps. For the task chosen, the performance of the observers was not affected by the contrast or experience of the observer. However, the naïve observers exhibited a different pattern of scrolling than the radiologists, which included a tendency toward higher number of direction changes and number of slices viewed. CONCLUSIONS: The authors have determined a distribution of speeds for volumetric detection tasks. The speed at detection was higher than that subjectively estimated by the radiologists before the experiment. The speed information that was measured will be useful in the development of 3D model observers, especially anthropomorphic model observers which try to mimic human behavior.

Maladies infectieuses [Infectious diseases]

In 2008, several publications have highlighted the role of climate change and globalization on the epidemiology of infectious diseases. Studies have shown the extension towards Europe of diseases such as Crimea-Congo fever (Kosovo, Turkey and Bulgaria), leismaniosis (Cyprus) and chikungunya virus infection (Italy). The article also contains comments on Plasmodium knowlesi, a newly identified cause of severe malaria in humans, as well as an update on human transmission of the H5NI avian influenza virus. It also mentions new data on Bell's palsy as well as two vaccines (varicella-zoster and pneumococcus), and provides a list of recent guidelines for the treatment of common infectious diseases.

Stem Cell Transplantation for Retinal Degenerations

Within the last few years, several reports have revealed that cell transplantation can be an effective way to replace lost neurons in the central nervous system (CNS) of patients affected with neurodegenerative diseases. Concerning the retina, the concept that newborn photoreceptors can integrate the retina and restore some visual functions was univocally demonstrated recently in the mouse eye (MacLaren et al. 2006) and remains to be achieved in human. These results pave the way to a standard approach in regenerative medicine aiming to replace lost photoreceptors. With the discovery of stem cells a great hope has appeared towards elaborating protocols to generate adequate cells to restore visual function in different retinal degeneration processes. Retinal stem cells (RSCs) are good candidates to repair the retina and are present throughout the retina development, including adulthood. However, neonatal mouse RSCs derived from the radial glia population have a different potential to proliferate and differentiate in comparison to adult RSCs. Moreover, we observed that adult mouse RSCs, depending on the culture conditions, have a marked tendency to transform, whereas neonatal RSCs show subtle chromosome abnormalities only after extensive expansion. These characteristics should help to identify the optimal cell source and culture conditions for cell transplantation studies. These results will be discussed in light of other studies using RSCs as well as embryonic stem cells. Another important factor to consider is the host environment, which plays a crucial role for cell integration and which was poorly studied in the normal and the diseased retina. Nonetheless, important results were recently generated to reconsider cell transplantation strategy. Perspectives to enhance cell integration by manipulating the environment will also be presented.

Microbiota abnormalities in inflammatory airway diseases - Potential for therapy.

Increasingly the development of novel therapeutic strategies is taking into consideration the contribution of the intestinal microbiota to health and disease. Dysbiosis of the microbial communities colonizing the human intestinal tract has been described for a variety of chronic diseases, such as inflammatory bowel disease, obesity and asthma. In particular, reduction of several so-called probiotic species including Lactobacilli and Bifidobacteria that are generally considered to be beneficial, as well as an outgrowth of potentially pathogenic bacteria is often reported. Thus a tempting therapeutic approach is to shape the constituents of the microbiota in an attempt to restore the microbial balance towards the growth of 'health-promoting' bacterial species. A twist to this scenario is the recent discovery that the respiratory tract also harbors a microbiota under steady-state conditions. Investigators have shown that the microbial composition of the airway flora is different between healthy lungs and those with chronic lung diseases, such as asthma, chronic obstructive pulmonary disease as well as cystic fibrosis. This is an emerging field, and thus far there is very limited data showing a direct contribution of the airway microbiota to the onset and progression of disease. However, should future studies provide such evidence, the airway microbiota might soon join the intestinal microbiota as a target for therapeutic intervention. In this review, we highlight the major advances that have been made describing the microbiota in chronic lung disease and discuss current and future approaches concerning manipulation of the microbiota for the treatment and prevention of disease.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: developing European guidelines in clinical microbiology and infectious diseases.

The process to develop a guideline in a European setting remains a challenge. The ESCMID Fungal Infection Study Group (EFISG) successfully achieved this endeavour. After two face-to-face meetings, numerous telephone conferences, and email correspondence, an ESCMID task force (basically composed of members of the Society's Fungal Infection Study Group, EFISG) finalized the ESCMID diagnostic and management/therapeutic guideline for Candida diseases. By appreciating various patient populations at risk for Candida diseases, four subgroups were predefined, mainly ICU patients, paediatric, HIV/AIDS and patients with malignancies including haematopoietic stem cell transplantation. Besides treatment recommendations, the ESCMID guidelines provide guidance for diagnostic procedures. For the guidelines, questions were formulated to phrase the intention of a given recommendation, for example, outcome. The recommendation was the clinical intervention, which was graded by a score of A-D for the 'Strength of a recommendation'. The 'level of evidence' received a score of I-III. The author panel was approved by ESCMID, European Organisation for Research and Treatment of Cancer, European Group for Blood and Marrow Transplantation, European Society of Intensive Care Medicine and the European Confederation of Medical Mycology. The guidelines followed the framework of GRADE and Appraisal of Guidelines, Research, and Evaluation. The drafted guideline was presented at ECCMID 2011 and points of discussion occurring during that meeting were incorporated into the manuscripts. These ESCMID guidelines for the diagnosis and management of Candida diseases provide guidance for clinicians in their daily decision-making process.

Sustaining sleep spindles through enhanced SK2-channel activity consolidates sleep and elevates arousal threshold.

Sleep spindles are synchronized 11-15 Hz electroencephalographic (EEG) oscillations predominant during nonrapid-eye-movement sleep (NREMS). Rhythmic bursting in the reticular thalamic nucleus (nRt), arising from interplay between Ca(v)3.3-type Ca(2+) channels and Ca(2+)-dependent small-conductance-type 2 (SK2) K(+) channels, underlies spindle generation. Correlative evidence indicates that spindles contribute to memory consolidation and protection against environmental noise in human NREMS. Here, we describe a molecular mechanism through which spindle power is selectively extended and we probed the actions of intensified spindling in the naturally sleeping mouse. Using electrophysiological recordings in acute brain slices from SK2 channel-overexpressing (SK2-OE) mice, we found that nRt bursting was potentiated and thalamic circuit oscillations were prolonged. Moreover, nRt cells showed greater resilience to transit from burst to tonic discharge in response to gradual depolarization, mimicking transitions out of NREMS. Compared with wild-type littermates, chronic EEG recordings of SK2-OE mice contained less fragmented NREMS, while the NREMS EEG power spectrum was conserved. Furthermore, EEG spindle activity was prolonged at NREMS exit. Finally, when exposed to white noise, SK2-OE mice needed stronger stimuli to arouse. Increased nRt bursting thus strengthens spindles and improves sleep quality through mechanisms independent of EEG slow waves (<4 Hz), suggesting SK2 signaling as a new potential therapeutic target for sleep disorders and for neuropsychiatric diseases accompanied by weakened sleep spindles.

Mortality from cardiovascular and cerebrovascular diseases in Europe and other areas of the world: an update.

OBJECTIVE: To update trends in mortality from coronary heart diseases (CHD) and cerebrovascular diseases (CVD) over the period 1981-2004 in Europe, the USA, Latin America, Japan and other selected areas of the world. METHODS: Age-standardized mortality rates were derived from the World Health Organization database. Joinpoint analysis was used to identify significant changes in trends. RESULTS: In the European Union (27 countries), CHD mortality in men declined from 139/100,000 in 1985-1989 to 93/100,000 in 2000-2004 (-33%). In women, the fall was from 61/100,000 to 44/100,000 (-27%). In this area, a decline by over 30% was also registered in CVD mortality for both sexes. In the Russian Federation and other countries of the former Soviet Union, CHD rates in 2000-2004 were exceedingly high, around 380/100,000 men and 170/100,000 women in Russia, 430 for men and 240 for women in Ukraine, 420 and 200 in Belarus. For CVD, a similar situation was registered, with mortality rates of 226/100,000 for men and 159/100,000 for women in 2004 in the Russian Federation, and more than 24% increase since the late 1980s for men and 15% for women. CHD and CVD mortality continued to decline in most Latin American countries, Australia and other areas considered, including Asia (even if with marked differences). CONCLUSION: Although mortality from CHD and CVD continues to decline in several areas of the world including most countries of Europe and of the America providing data and Australia, unfavourable trends were still observed in the Russian Federation and other countries of the former Soviet Union, whose recent rates remain exceedingly high.