Terrestrial laser scanning for landslides deformation monitoring

Within last few years a new type of instruments called Terrestrial Laser Scanners (TLS) entered to the commercial market. These devices brought a possibility to obtain completely new type of spatial, three dimensional data describing the object of interest. TLS instruments are generating a type of data that needs a special treatment. Appearance of this technique made possible to monitor deformations of very large objects, like investigated here landslides, with new quality level. This change is visible especially with relation to the size and number of the details that can be observed with this new method. Taking into account this context presented here work is oriented on recognition and characterization of raw data received from the TLS instruments as well as processing phases, tools and techniques to do them. Main objective are definition and recognition of the problems related with usage of the TLS data, characterization of the quality single point generated by TLS, description and investigation of the TLS processing approach for landslides deformation measurements allowing to obtain 3D deformation characteristic and finally validation of the obtained results. The above objectives are based on the bibliography studies and research work followed by several experiments that will prove the conclusions.

Does abdominoplasty with liposuction of the love handles yield a shorter scar? An analysis with abdominal 3D laser scanning.

The aim of this study was to evaluate the combination of abdominoplasty with liposuction of both flanks with regards to length of scar, complications, and patient's satisfaction. A retrospective analysis of 35 patients who underwent esthetic abdominoplasty at our institution between 2002 and 2004 was performed. Thirteen patients underwent abdominoplasty with liposuction of both flanks, 22 patients underwent conventional abdominoplasty. Liposuction of the flanks did not increase the rate of complications of the abdominoplasty procedures. We found a tendency toward shorter scars in patients who underwent abdominoplasty combined with liposuction of the flanks. Implementation of 3-dimensional laser surface scanning to objectify the postoperative outcomes, documented a comparable degree of flatness of the achieved body contouring in both procedures. 3-dimensional laser surface scanning can be a valuable tool to objectify assessment of postoperative results.

Performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of bacterial strains routinely isolated in a clinical microbiology laboratory.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been introduced in diagnostic microbiology laboratories for the identification of bacterial and yeast strains isolated from clinical samples. In the present study, we prospectively compared MALDI-TOF MS to the conventional phenotypic method for the identification of routine isolates. Colonies were analyzed by MALDI-TOF MS either by direct deposition on the target plate or after a formic acid-acetonitrile extraction step if no valid result was initially obtained. Among 1,371 isolates identified by conventional methods, 1,278 (93.2%) were putatively identified to the species level by MALDI-TOF MS and 73 (5.3%) were identified to the genus level, but no reliable identification was obtained for 20 (1.5%). Among the 1,278 isolates identified to the species level by MALDI-TOF MS, 63 (4.9%) discordant results were initially identified. Most discordant results (42/63) were due to systematic database-related taxonomical differences, 14 were explained by poor discrimination of the MALDI-TOF MS spectra obtained, and 7 were due to errors in the initial conventional identification. An extraction step was required to obtain a valid MALDI-TOF MS identification for 25.6% of the 1,278 valid isolates. In conclusion, our results show that MALDI-TOF MS is a fast and reliable technique which has the potential to replace conventional phenotypic identification for most bacterial strains routinely isolated in clinical microbiology laboratories.

Photodynamic therapy : a pathway for enhanced delivery of liposomal doxorubicin to tumors

Abstract Part I : Background : Isolated lung perfusion (ILP) was designed for the treatment of loco-regional malignancies of the lung. In contrast to intravenous (IV) drug application, ILP allows for a selective administration of cytostatic agents such as doxorubicin to the lung while sparing non-affected tissues. However, the clinical results with ILP were disappointing. Doxorubicinbased ILP on sarcoma rodent lungs suggested high overall doxorubicin concentrations within the perfused lung but a poor penetration of the cytostatic agent into tumors. The same holds true for liposomal-encapsulated macromolecular doxorubicin (LiporubicinTM) In specific conditions, low-dose photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial bamer in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vasculature. We therefore hypothesized that Visudyne®-mediated PDT could selectively increase liposomal doxorubicin (LiporubicinTM) uptake in sarcoma tumors to rodent lungs during intravenous (IV) drug administration and isolated lung perfusion (ILP). Material and Methods : A sarcoma tumor was generated in the left lung of Fisher rats by subpleural injection of a sarcoma cell ,suspension via thoracotomy. Ten days later, LiporubicinTM is administered IV or by single pass antegrade ILP, with or without Visudyne® -mediated low-dose PDT pre-treatment of the sarcoma bearing lung. The drug concentration and distribution were assessed separately in tumors and lung tissues by high pressure liquid chromatography (HPLC) and fluorescence microscopy (FNI~, respectively. Results : PDT pretreatment before IV LiporubicinTM administration resulted in a significantly higher tumor drug uptake and tumor to lung drug ratio compared to IV drug injection alone without affecting the blood flow and drug distribution in the lung. PDT pre-treatment before LiporubicinTM-based ILP also resulted in a higher tumor drug uptake and a higher tumor to lung drug ratio compared to ILP alone, however, these differences were not significant due to a heterogeneous blood flow drug distribution during ILP which was further accentuated by PDT. Conclusions : Low-dose Visudyne®-mediated PDT pre-treatment has the potential to selectively enhance liposomal encapsulated doxorubicin uptake in tumors but not in normal lung tissue after IV drug application in a rat model of sarcoma tumors to the lung which opens new perspectives for the treatment of superficially spreading chemoresistant tumors of the chest cavity such as mesothelioma or malignant effusion. However, the impact of PDT on macromolecular drug uptake during ILP is limited since its therapeutic advantage is circumvented by ILP-induced heterogeneicity of blood flow and drug distribution Abstract Part II Background : Photodynamic therapy (PDT) with Visudyne® acts by direct cellular phototoxicity and/or by an indirect vascular-mediated effect. Here, we demonstrate that the vessel integrity interruption by PDT can promote the extravasation of a macromolecular agent in normal tissue. To obtain extravasation in normal tissue PDT conditions were one order of magnitude more intensive than the ones in tissue containing neovessels reported in the literature. Material and Methods : Fluorescein isothiocyanate dextran (FITC-D, 2000kDa), a macromolecular agent, was intravenously injected 10 minutes before (LKO group, n=14) or 2 hours (LK2 group, n=16) after Visudyne® mediated PDT in nude mice bearing a dorsal skin fold chamber. Control animals had no PDT (CTRL group, n=8). The extravasation of FITC-D from blood vessels in striated muscle tissue was observed in both groups in real-time for up to 2500 seconds after injection. We also monitored PDT-induced leukocyte rolling in-vivo and assessed, by histology, the corresponding inflammatory reaction score in the dorsal skin fold chambers. Results : In all animals, at the applied PDT conditions, FITC-D extravasation was significantly enhanced in the PDT treated areas as compared to the surrounding non-treated areas (p<0.0001). There was no FITC-D leakage in the control animals. Animals from the LKO group had significantly less FITC-D extravasation than those from the LK2 group (p = 0.0002). In the LKO group FITC-D leakage correlated significantly with the inflammation (p < 0.001). Conclusions: At the selected conditions, Visudyne-mediated PDT promotes vascular leakage and FITC-D extravasation into the interstitial space of normal tissue. The intensity of vascular leakage depends on the time interval between PDT and FITC-D injection. This concept could be used to locally modulate the delivery of macromolecules in vivo. Résumé : La perfusion cytostatique isolée du poumon permet une administration sélective des agents cytostatiques sans implication de la circulation systémique avec une forte accumulation au niveau du poumon mais une faible pénétration dans les tumeurs. La thérapie photodynamique (PDT) qui consiste en l'application d'un sensibilisateur activé par lumière laser non- thermique d'une longueur d'onde définie permet dans certaines conditions, une augmentation de la pénétration des agents cytostatiques macromoléculaires à travers la barrière endothéliale tumorale. Nous avons exploré cet avantage thérapeutique de la PDT dans un modèle expérimental afin d'augmenter d'une manière sélective la pénétration tumorale de la doxorubicin pegylée, liposomal- encapsulée macromoléculaire (Liporubicin). Une tumeur sarcomateuse a été générée au niveau du poumon de rongeur suivie d'administration de Liporubicin, soit par voie intraveineuse soit par perfusion isolée du poumon (ILP). Une partie des animaux ont reçus un prétraitement de la tumeur et du poumon sous jacent par PDT avec Visudyne comme photosensibilisateur. Les résultats ont démontrés que la PDT permet, sous certaines conditions, une augmentation sélective de Liporubicin dans les tumeurs mais pas dans le parenchyme pulmonaire sous jacent. Après administration intraveineuse de Liporubicin et prétraitement par PDT, l'accumulation dans les tumeurs était significative par rapport au poumon, et aux tumeurs sans PDT. Le même phénomène est observé après ILP du poumon. Cependant, les différences avec ou sans PDT n'étaient pas significatives lié à und distribution hétérogène de Liporubicin dans le poumon perfusé après ILP. Dans une deuxième partie de l'expérimentation, nous avons exploré la microscopie intra-vitale pour déterminer l'extravasion des substances macromoléculaires (FITS) à travers la barrière endothéliale avec ou sans Visudyne-PDT au niveau des chambres dorsales des souris nues. Les résultats montrent qu'après PDT, l'extravasion de FITS a été augmentée de manière significative par rapport au tissu non traité. L'intensité de l'extravasion de FITS dépendait également de l'intervalle entre PDT et injection de FITS. En conclusion, les expérimentations montrent que la PDT est capable, sous certaines conditions, d'augmenter de manière significative l'extravasion des macromolécules à travers la barrière endothéliale et leur accumulation dans des tumeurs mais pas dans le parenchyme pulmonaire. Ces résultats permettent une nouvelle perspective de traitement pour des tumeurs superficielles intrathoraciques chimio-résistent comme l'épanchement pleural malin ou le mésothéliome pleural.

Femtosecond-laser assisted cataract surgery: a review.

Introduced in 2008, the femtosecond laser is a promising new technological advance which plays an ever increasing role in cataract surgery where it automates the three main surgical steps: corneal incision, capsulotomy and lens fragmentation. The proven advantages over manual surgery are: a better quality of incision with reduced induced astigmatism; increased reliability and reproducibility of the capsulotomy with increased stability of the implanted lens; a reduction in the use of ultrasound. Regarding refractive results or safety, however, no prospective randomized study to date has shown significant superiority compared with standard manual technique. The significant extra cost generated by this laser, undertaken by the patient, is a limiting factor for both its use and study. This review outlines the potential benefits of femtosecond-laser-assisted cataract surgery due to the automation of key steps and the safety of this new technology.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry for direct bacterial identification from positive blood culture pellets.

An ammonium chloride erythrocyte-lysing procedure was used to prepare a bacterial pellet from positive blood cultures for direct matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry analysis. Identification was obtained for 78.7% of the pellets tested. Moreover, 99% of the MALDI-TOF identifications were congruent at the species level when considering valid scores. This fast and accurate method is promising.

Predators promote defence of rhizosphere bacterial populations by selective feeding on non-toxic cheaters.

Soil pseudomonads increase their competitiveness by producing toxic secondary metabolites, which inhibit competitors and repel predators. Toxin production is regulated by cell-cell signalling and efficiently protects the bacterial population. However, cell communication is unstable, and natural populations often contain signal blind mutants displaying an altered phenotype defective in exoproduct synthesis. Such mutants are weak competitors, and we hypothesized that their fitness depends on natural communities on the exoproducts of wild-type bacteria, especially defence toxins. We established mixed populations of wild-type and signal blind, non-toxic gacS-deficient mutants of Pseudomonas fluorescens CHA0 in batch and rhizosphere systems. Bacteria were grazed by representatives of the most important bacterial predators in soil, nematodes (Caenorhabditis elegans) and protozoa (Acanthamoeba castellanii). The gacS mutants showed a negative frequency-dependent fitness and could reach up to one-third of the population, suggesting that they rely on the exoproducts of the wild-type bacteria. Both predators preferentially consumed the mutant strain, but populations with a low mutant load were resistant to predation, allowing the mutant to remain competitive at low relative density. The results suggest that signal blind Pseudomonas increase their fitness by exploiting the toxins produced by wild-type bacteria, and that predation promotes the production of bacterial defence compounds by selectively eliminating non-toxic mutants. Therefore, predators not only regulate population dynamics of soil bacteria but also structure the genetic and phenotypic constitution of bacterial communities.

Separation of free amino acids in human plasma by capillary electrophoresis with laser induced fluorescence: potential for emergency diagnosis of inborn errors of metabolism.

Free amino acids (AAs) in human plasma are derivatized with 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA) and analyzed by capillary electrophoresis (CE) with laser induced fluorescence (LIF) detection. The labeling procedure is significantly improved over results reported previously. Derivatization can be completed in 40 min, with concentrations as low as 4 x 10(-8) M successfully labeled in favourable cases. Twenty-nine AAs (including 2 internal standards) are identified and can be reproducibly separated in 70 min. Migration time RSD values for 23 of these AAs were calculated and found in the range from 0.5 to 4%. The rapid derivatization procedure and the resolution obtained in the separation are sufficient for a semi-quantitative, emergency diagnosis of several inborn errors of metabolism (IEM). Amino acid profiles for both normal donor plasma samples and plasma samples of patients suffering from phenylketonuria, tyrosinemia, maple syrup urinary disease, hyperornithinemia, and citrullinemia are studied.

Use of terrestrial laser scanning for the characterization of retrogressive landslides in sensitive clay and rotational landslides in river banks

Depuis plus de 10 ans les modèles numériques d'altitude (MNA) produits par technologie de « light detection and ranging » (« LIDAR ») ont fourni de nouveaux outils très utiles pour des études géomorphologiques, particulièrement dans le cas des glissements de terrain. Le balayage laser terrestre (« TLS ») permet une utilisation très souple. Le TLS peut être employé pour la surveillance ou dans des situations d'urgence qui nécessitent une acquisition rapide d'un MNA afin d'évaluer l'aléa. Au travers de trois exemples, nous démontrons l'utilité du TLS pour la quantification de volumes de glissements de terrain, la création de profils et l'analyse de séries temporelles. Ces études de cas sont des glissements de terrain situés dans les argiles sensibles de l'est du Canada (Québec, Canada) ou de petits glissements rotationnels dans les berges d'une rivière (Suisse).

Selective abrogation of major histocompatibility complex class II expression on extrahematopoietic cells in mice lacking promoter IV of the class II transactivator gene.

MHC class II (MHCII) molecules play a pivotal role in the induction and regulation of immune responses. The transcriptional coactivator class II transactivator (CIITA) controls MHCII expression. The CIITA gene is regulated by three independent promoters (pI, pIII, pIV). We have generated pIV knockout mice. These mice exhibit selective abrogation of interferon (IFN)-gamma-induced MHCII expression on a wide variety of non-bone marrow-derived cells, including endothelia, epithelia, astrocytes, and fibroblasts. Constitutive MHCII expression on cortical thymic epithelial cells, and thus positive selection of CD4(+) T cells, is also abolished. In contrast, constitutive and inducible MHCII expression is unaffected on professional antigen-presenting cells, including B cells, dendritic cells, and IFN-gamma-activated cells of the macrophage lineage. pIV(-/-) mice have thus allowed precise definition of CIITA pIV usage in vivo. Moreover, they represent a unique animal model for studying the significance and contribution of MHCII-mediated antigen presentation by nonprofessional antigen-presenting cells in health and disease.

Expression of a functional single chain antibody on the surface of extracellular enveloped vaccinia virus as a step towards selective tumour cell targeting.

Recombinant vaccinia virus with tumour cell specificity may provide a versatile tool either for direct lysis of cancer cells or for the targeted transfer of genes encoding immunomodulatory molecules. We report the expression of a single chain antibody on the surface of extracellular enveloped vaccinia virus. The wild-type haemagglutinin, an envelope glycoprotein which is not required for viral infection and replication, was replaced by haemagglutinin fusion molecules carrying a single chain antibody directed against the tumour-associated antigen ErbB2. ErbB2 is an epidermal growth factor receptor-related tyrosine kinase overexpressed in a high percentage of human adenocarcinomas. Two fusion proteins carrying the single chain antibody at different NH2-terminal positions were expressed and exposed at the envelope of the corresponding recombinant viruses. The construct containing the antibody at the site of the immunoglobulin-like loop of the haemagglutinin was able to bind solubilized ErbB2. This is the first report of replacement of a vaccinia virus envelope protein by a specific recognition structure and represents a first step towards modifying the host cell tropism of the virus.

Selective lysis of activated cells in oncorna virus infection.

The authors devised a cytotoxic assay based on cytofluorometric analysis of target surface markers in order to compare lysis exerted in vitro by cytotoxic T lymphocytes (CTLs) on different cell subsets in the context of a single lymphoid target cell population. Using this assay, the authors evaluated when oncorna virus-infected lymphocytes become a suitable target for virus-specific T cell effectors. A lymphocyte population from Moloney-murine leukaemia virus (M-MuLV)-infected (carrier) mice, in which the proliferation of selective V beta T-cell receptor (TCR) families was induced in response to Mlsa encoded antigens, was utilized as a target. The authors observed that a virus-specific T cell clone exerted lytic activity preferentially against activated cell subsets. Moreover, virus-specific CTLs generated in mixed leucocyte tumour cell cultures (MLTC) were also able to impair the concomitant anti-Mlsa response of lymphocytes from M-MuLV carrier mice. It was found that the proliferative status of oncorna virus-infected target cells played an important role in limiting the in vitro efficacy of the immune response, and it is speculated that this phenomenon might represent an in vivo escape mechanism from immunosurveillance.

Efficient gene delivery and selective transduction of astrocytes in the mammalian brain using viral vectors.

Astrocytes are now considered as key players in brain information processing because of their newly discovered roles in synapse formation and plasticity, energy metabolism and blood flow regulation. However, our understanding of astrocyte function is still fragmented compared to other brain cell types. A better appreciation of the biology of astrocytes requires the development of tools to generate animal models in which astrocyte-specific proteins and pathways can be manipulated. In addition, it is becoming increasingly evident that astrocytes are also important players in many neurological disorders. Targeted modulation of protein expression in astrocytes would be critical for the development of new therapeutic strategies. Gene transfer is valuable to target a subpopulation of cells and explore their function in experimental models. In particular, viral-mediated gene transfer provides a rapid, highly flexible and cost-effective, in vivo paradigm to study the impact of genes of interest during central nervous system development or in adult animals. We will review the different strategies that led to the recent development of efficient viral vectors that can be successfully used to selectively transduce astrocytes in the mammalian brain.