Off-axis low-coherence interferometry for surface topology measurement.

In this communication we introduce a low or reduced coherence interferometry technique that can be used to retrieve surface topology on samples with high roughness. Moreover, we will show that the approach enables surface topology measurement also at the interface of so-called turbid media, where multiple scattering inside tissues can be a major issue, preventing accurate measurements.

Characterisation of the putative effector interaction site of the regulatory HbpR protein from Pseudomonas azelaica by site-directed mutagenesis.

Bacterial transcription activators of the XylR/DmpR subfamily exert their expression control via σ(54)-dependent RNA polymerase upon stimulation by a chemical effector, typically an aromatic compound. Where the chemical effector interacts with the transcription regulator protein to achieve activation is still largely unknown. Here we focus on the HbpR protein from Pseudomonas azelaica, which is a member of the XylR/DmpR subfamily and responds to biaromatic effectors such as 2-hydroxybiphenyl. We use protein structure modeling to predict folding of the effector recognition domain of HbpR and molecular docking to identify the region where 2-hydroxybiphenyl may interact with HbpR. A large number of site-directed HbpR mutants of residues in- and outside the predicted interaction area was created and their potential to induce reporter gene expression in Escherichia coli from the cognate P(C) promoter upon activation with 2-hydroxybiphenyl was studied. Mutant proteins were purified to study their conformation. Critical residues for effector stimulation indeed grouped near the predicted area, some of which are conserved among XylR/DmpR subfamily members in spite of displaying different effector specificities. This suggests that they are important for the process of effector activation, but not necessarily for effector specificity recognition.

Tumor targeting with newly designed biparatopic antibodies directed against two different epitopes of the carcinoembryonic antigen (CEA).

In an attempt to improve tumor targeting and tumor retention time of monoclonal antibodies (MAbs), we prepared biparatopic antibodies (BpAbs) having the capability of binding 2 different non-overlapping epitopes on the same target antigen molecule, namely, the carcinoembryonic antigen (CEA). Six BpAbs were constructed by coupling 2 different Fab' fragments from 4 different specific anti-CEA MAbs recognizing 4 CEA epitopes (Gold 1-4). Demonstration of the double paratopic binding of these antibodies for CEA was confirmed in vitro by inhibition radioimmunoassay and cross-inhibition analysis by surface plasmon resonance (SPR; BIACORE) technology. Using the latter technique, the affinity constants for CEA immobilized onto the sensor chip were found to range from 0.37 to 1.54 x 10(9) M(-1) for the 4 parental F(ab')2 fragments and from 1.88 to 10.14 x 10(9) M(-1) for the BpAbs, demonstrating the advantage of biparatopic binding over conventional F(ab')2 binding. The Ka improvement was particularly high for BpAb F6/35A7 and BpAb F6/B17 with a 9.5- and 8.1-fold increase, respectively, as compared with the parental F(ab')2. In vivo, the 6 BpAbs were compared with their 2 respective parental F(ab')2 by injection of 131I-BpAb/125I-F(ab')2 parental fragments into nude mice xenografted with the human colon carcinoma T380. Dissection 72 hr post-injection demonstrated that BpAb B17/CE25 and BpAb F6/B17 gave higher tumor uptake than that of their parental F(ab')2. This finding is particularly interesting for BpAb F6/B17, which compared favorably with the F6 F(ab')2, one of the best parental F(ab')2 fragments used in our study.

Transient suppression of Shigella flexneri type 3 secretion by a protective O-antigen-specific monoclonal IgA.

Mucosal immunity to the enteric pathogen Shigella flexneri is mediated by secretory IgA (S-IgA) antibodies directed against the O-antigen (O-Ag) side chain of lipopolysaccharide. While secretory antibodies against the O-Ag are known to prevent bacterial invasion of the intestinal epithelium, the mechanisms by which this occurs are not fully understood. In this study, we report that the binding of a murine monoclonal IgA (IgAC5) to the O-Ag of S. flexneri serotype 5a suppresses activity of the type 3 secretion (T3S) system, which is necessary for S. flexneri to gain entry into intestinal epithelial cells. IgAC5's effects on the T3S were rapid (5 to 15 min) and were coincident with a partial reduction in the bacterial membrane potential and a decrease in intracellular ATP levels. Activity of the T3S system returned to normal levels 45 to 90 min following antibody treatment, demonstrating that IgAC5's effects were transient. Nonetheless, these data suggest a model in which the association of IgA with the O-Ag of S. flexneri partially de-energizes the T3S system and temporarily renders the bacterium incapable of invading intestinal epithelial cells. IMPORTANCE: Secretory IgA (S-IgA) serves as the first line of defense against enteric infections. However, despite its well-recognized role in mucosal immunity, relatively little is known at the molecular level about how this class of antibody functions to prevent pathogenic bacteria from penetrating the epithelial barrier. It is generally assumed that S-IgA functions primarily by "immune exclusion," a phenomenon in which the antibody binds to microbial surface antigens and thereby promotes bacterial agglutination, entrapment in mucus, and physical clearance from the gastrointestinal tract via peristalsis. The results of the present study suggest that in addition to serving as a physical barrier, S-IgA may have a direct impact on the ability of microbial pathogens to secrete virulence factors required for invasion of intestinal epithelial cells.

Position Document of the Secretariat on System-Wide Coherence in the context of UN Reform Processes

The present document should be seen as one more contribution to the debate to the reform processes and a small guide to these processes and their latest outcomes.

A civil society response on the report of the UN High-Level Panel on system-wide coherence

Abordamos el Informe del Grupo de Alto Nivel sobre la Coherencia en todo el Sistema de las Naciones Unidas («Informe del Grupo») y el proceso de reforma de las Naciones Unidas del que forma parte como grupos de la sociedad civil que tienen una larga experiencia por lo que se refiere a propugnar reformas del sistema de las Naciones Unidas.

Comparison of central macular thickness (CMT) measurement between time domain and spectral domain (SD) optical coherence tomography (OCT) and reproducibility of SD OCT in active neovascular AMD

Purpose: To evaluate the reproducibility of Cirrus-SD OCT measurements and to compare central macular thickness (CMT) measurements between TD-Stratus and SD-Cirrus OCT in patients with active exudative AMD. Methods: Consecutive case series of patients with active exudative AMD seen in the Medical Retina Department. Patients underwent 1 scan with Stratus (macular thickness map protocol) and 5 scans with Cirrus (Macular Cube protocol) at the same visit by the same experienced examiner. To be included, patients best-corrected visual acuity (BCVA) had to be >20/200 while all scans had to be of sufficient quality, well-centered and at least one Cirrus scan with CMT >300 microns. The repeatability of the SD Cirrus was estimated by using all 5 CMT measurements and the mean of the Cirrus measurements was compared with the CMT obtained by TD Stratus. Results: Cirrus OCT demonstrated high intraobserver repeatability at the central foveal region (ICC 96%). The mean of the CMT measurements was 321microns for Stratus and 387 microns for Cirrus. The average difference was 65m (SD=30). The coefficient of concordance between Stratus and Cirrus CMT measurements was rho=0,749 with a high precision and a moderate accuracy. The equation of the line of regression between Stratus and meanCirrus is given by the following: M_stratus = 0,848 x m_cirrus - 4,496 (1).Conclusions: The Cirrus macular cube protocol allows reproducible CMT measurements in patients with active exudative AMD. In cases of upgrading from TD to SD use and vice versa, there is the possibility to predict the measurements by using the equation (1). These real life data and conclusions can help in improving our clinical management of patients with neovascular AMD.

A case of acute retinal pigment epithelitis: spectral domain optical coherence tomography time course and physiopathologic hypothesis.

PURPOSE: To report the time course of retinal morphologic changes in a patient with acute retinal pigment epithelitis (ARPE) using spectral domain optical coherence tomography (SD-OCT). METHODS: A 30-year old man was referred for blurred vision of his right eye after five days that appeared suddenly 15 days after recovery from a flu-like syndrome. SD-OCT was performed immediately, followed by fluorescein and infracyanine angiography at eight days and then at three weeks. RESULTS: At presentation, a bubble of sub-macular deposit was observed on the right macula with central golden micronodules in a honeycomb pattern. SD-OCT showed an "anterior dislocation" of all the retinal layers up to the inner/outer segment (IS/OS) line and irregular deposits at the OS level together with thickening of the retinal pigment epithelial (RPE) layer. As visual acuity increased, eight days later, the OCT showed reduction of the sub-retinal deposits and an abnormal hyperflectivity of the sub-retinal and RPE layers was observed. The patient showed a positive serology for picornavirus. DISCUSSION: The acute SD-OCT sections of this patient with ARPE were compared with histological sections of a 35 day old Royal College of Surgeons rat. Similar findings could be observed, with preservation of the IS/OS line and accumulation of debris at the OS level, suggesting that ARPE symptoms could result from a transient phagocytic dysfunction of the RPE at the fovea, inducing reversible accumulation of undigested OS. Picornaviruses comprising enterovirus and coxsachievirus described as being associated with acute chorioretinitis. In this case, it was responsible for ARPE. CONCLUSION: We hypothesize that ARPE syndrome results from a transient dysfunction of RPE, which can occur as a post viral reaction.

Partial protection and intrathecal invasion of CD8(+) T cells in acute canine distemper virus infection.

Initial non-inflammatory demyelination in canine distemper virus infection (CDV) develops against a background of severe immunosuppression and is therefore, thought to be virus-induced. However, recently we found a marked invasion of T cells throughout the central nervous system (CNS) in dogs with acute distemper despite drastic damage to the immune system. In the present study, this apparent paradox was further investigated by immunophenotyping of lymphocytes, following experimental CDV challenge in vaccinated and non-vaccinated dogs. In contrast to CDV infected, unprotected dogs, vaccinated dogs did not become immunosuppressed and exhibited a strong antiviral immune response following challenge with virulent CDV. In unprotected dogs rapid and drastic lymphopenia was initially due to depletion of T cells. In peripheral blood, CD4(+) T cells were more sensitive and depleted earlier and for a longer time than CD8(+) cells which recovered soon. In the cerebrospinal fluid (CSF) we could observe an increase in the T cell to B cell and CD8(+) to CD4(+) ratios. Thus, partial protection of the CD8(+) cell population could explain why part of the immune function in acute distemper is preserved. As found earlier, T cells invaded the CNS parenchyma in these dogs but also in the protected challenged dogs, which did not develop any CNS disease at all. Since markers of T cell activation were upregulated in both groups of animals, this phenomenon could in part be related to non-specific penetration of activated T cells through the blood brain barrier. However, in diseased animals much larger numbers of T cells were found in the CNS than in the protected dogs, suggesting that massive invasion of T cells in the brain requires CDV expression in the CNS.

Reconstruction of 3D Planar Objects with Partial Occlusion

Kolmiulotteisten kappaleiden rekonstruktio on yksi konenäön haastavimmista ongelmista, koska kappaleiden kolmiulotteisia etäisyyksiä ei voida selvittää yhdestä kaksiulotteisesta kuvasta. Ongelma voidaan ratkaista stereonäön avulla, jossa näkymän kolmiulotteinen rakenne päätellään usean kuvan perusteella. Tämä lähestymistapa mahdollistaa kuitenkin vain rekonstruktion niille kappaleiden osille, jotka näkyvät vähintään kahdessa kuvassa. Piilossa olevien osien rekonstruktio ei ole mahdollista pelkästään stereonäön avulla. Tässä työssä on kehitetty uusi menetelmä osittain piilossa olevien kolmiulotteisten tasomaisten kappaleiden rekonstruktioon. Menetelmän avulla voidaan selvittää hyvällä tarkkuudella tasomaisista pinnoista koostuvan kappaleen muoto ja paikka käyttäen kahta kuvaa kappaleesta. Menetelmä perustuu epipolaarigeometriaan, jonka avulla selvitetään molemmissa kuvissa näkyvät kappaleiden osat. Osittain piilossa olevien piirteiden rekonstruointi suoritetaan käyttämäen stereonäköä sekä tietoa kappaleen rakenteesta. Esitettyä ratkaisua voitaisiin käyttää esimerkiksi kolmiulotteisten kappaleiden visualisointiin, robotin navigointiin tai esineentunnistukseen.

Partial cricotracheal resection for paediatric subglottic stenosis: update of the Lausanne experience with 129 cases.

OBJECTIVES: Partial cricotracheal resection (PCTR) is widely accepted for treating severe paediatric laryngotracheal stenosis (LTS). However, it remains limited to a few experienced centres. Here we report an update of the Lausanne experience in paediatric PCTR performed or supervised by a senior surgeon (Philippe Monnier). METHODS: An ongoing database of 129 paediatric patients who underwent PCTR for benign LTS between March 1978 and July 2012 at our hospital was retrospectively reviewed. Demographic characteristics and information on preoperative status, stenosis and surgery were collected. Primary outcomes were measured as overall and operation-specific decannulation rates (ODR and OSDR, respectively), and secondary outcomes as morbidity, mortality and postoperative functional results. RESULTS: A total of 129 paediatric patients [79 males and 50 females; mean age, 4.1 years (1 month-16 years, median age of 2 years old)] underwent PCTR during the study period. ODR and OSDR were 90 and 81%, respectively. The decannulation rates were significantly superior for single-stage PCTR compared with double-stage PCTR in both ODR and OSDR. Eight patients died postoperatively for reasons unrelated to surgery. Partial anastomotic dehiscence was seen in 13 patients, 9 of whom were successfully treated by revision surgery. Respiratory, voice and swallowing functions were near normal or only minimally impaired in 86, 65 and 81% of patients, respectively. CONCLUSIONS: PCTR is effective and feasible with good ODR and OSDR for highgrade / severe LTS. Glottic involvement and the presence of comorbidities were negative predictive factors of decannulation. Early detection and reintervention of postoperative incipient dehiscence contribute to avoiding the progress to late restenosis; however, voice improvement remains a challenge.