A low-cost and versatile system for projecting wide-field visual stimuli within fMRI scanners.

We have constructed and tested a custom-made magnetic-imaging-compatible visual projection system designed to project on a very wide visual field (~80°). A standard projector was modified with a coupling lens, projecting images into the termination of an image fiber. The other termination of the fiber was placed in the 3-T scanner room with a projection lens, which projected the images relayed by the fiber onto a screen over the head coil, viewed by a participant wearing magnifying goggles. To validate the system, wide-field stimuli were presented in order to identify retinotopic visual areas. The results showed that this low-cost and versatile optical system may be a valuable tool to map visual areas in the brain that process peripheral receptive fields.

Mid-infrared digital holography and holographic interferometry with a tunable quantum cascade laser.

Mid-infrared digital holography based on CO2 lasers has proven to be a powerful coherent imaging technique due to reduced sensitivity to mechanical vibrations, increased field of view, high optical power, and possible vision through scattering media, e.g., smoke. Here we demonstrate a similar and more compact holographic system based on an external cavity quantum cascade laser emitting at 8 µm. Such a setup, which includes a highly sensitive microbolometric camera, allows the acquisition of speckle holograms of scattering objects, which can be processed in real time. In addition, by exploiting the broad laser tunability, we can acquire holograms at different wavelengths, from which we extract phase images not subjected to phase wrapping, at synthetic wavelengths ranging from hundreds of micrometers to several millimeters.

Imaging live humans through smoke and flames using far-infrared digital holography.

The ability to see behind flames is a key challenge for the industrial field and particularly for the safety field. Development of new technologies to detect live people through smoke and flames in fire scenes is an extremely desirable goal since it can save human lives. The latest technologies, including equipment adopted by fire departments, use infrared bolometers for infrared digital cameras that allow users to see through smoke. However, such detectors are blinded by flame-emitted radiation. Here we show a completely different approach that makes use of lensless digital holography technology in the infrared range for successful imaging through smoke and flames. Notably, we demonstrate that digital holography with a cw laser allows the recording of dynamic human-size targets. In this work, easy detection of live, moving people is achieved through both smoke and flames, thus demonstrating the capability of digital holography at 10.6 µm.

[Fertility preservation among patients with cancer: report of a French regional practical experience]. / Préservation de la fertilité en oncologie : bilan des pratiques en Région PACA-Corse.

OBJECTIVE: Improvement in cancer treatments has led to reconsider the importance of quality of life after cancer, especially concerning maintening the potential of fertility since it is often altered after healing. Our objective was to estimate the knowledge and practices of the physicians in the field of Oncology in a French Region (Provence Alpes- Côte d'Azur). PATIENTS AND METHOD: Prospective survey, conducted between January and April 2012, amongst oncologists working in Provence Alpes Côte d'Azur region, through questionnaires distributed during multidisciplinary meetings in oncology. RESULTS: Among 225 replies, 54% of the physicians had sent no patient to any oncofertility consultation during the previous six months (n=120). Besides, 33% of the oncologists (n=68) declared they had difficulties in addressing their patients to oncofertility consultation, and 58% of them (n=39) considered they lacked information on techniques and indications of fertility preservation. CONCLUSION: This study provides an estimation of the current practices in PACA region concerning oncofertility and underlines the physicians' need of information. In this context, the regional oncology network has set up a regional network « cancer and fertility ¼ in order to facilitate the access to fertility preservation prior to any potentially sterilizing treatment for all patients.

Characterizing dynamics with covariant Lyapunov vectors.

A general method to determine covariant Lyapunov vectors in both discrete- and continuous-time dynamical systems is introduced. This allows us to address fundamental questions such as the degree of hyperbolicity, which can be quantified in terms of the transversality of these intrinsic vectors. For spatially extended systems, the covariant Lyapunov vectors have localization properties and spatial Fourier spectra qualitatively different from those composing the orthonormalized basis obtained in the standard procedure used to calculate the Lyapunov exponents.

[Autotransplantation of an immature tooth]. / Autotransplantation de dent immature.

Autogenous tooth transplantation is indicated in young people treated by orthodontology, especially when they present with damaged first molars requiring extraction. This therapeutic alternative with a favourable prognosis is an elegant solution after a single tooth loss.

Histological evaluation of buccal penetration enhancement properties of chitosan and trimethyl chitosan.

The aim of the present work was to compare the penetration enhancement properties of chitosan hydrochloride (HCS) both as a polymeric solution and as a nanoparticulate system with that of trimethyl chitosan hydrochloride (TMC) on buccal mucosa. The hydrophilic high molecular weight fluorescein isothiocyanate dextran (FD4; 4400 Da) was used as a macromolecule model. The mechanism involved in the HCS (solution and nanoparticles) and TMC solution penetration enhancement was investigated on pig buccal mucosa, characterized by having stratified epithelium and lacking in tight junctions. The permeation/penetration of FD4 and the change in morphology and histology of the mucosa after contact with the polymers were assessed: the experiments were performed ex-vivo by applying the formulations on excised porcine buccal tissue. For the morphology and the histology studies, the epithelial cell layers from freshly excised pig buccal mucosa were analysed with light microscopy by means of routine histopathology analysis (haematoxylin and eosin staining and Toluidine blue staining) and immunohistochemistry reactions. The organization of desmosomal junctions was assessed by means of an immunochemical reaction on desmosomes and transmission electron microscopy. Confocal laser scanning microscopy (CLSM) was used to find evidence of the location of FD4 in the tissue. Furthermore, the increase of the FD4 apparent permeability coefficient was quantified by means of Franz diffusion cells using isolated buccal epithelium to demonstrate the penetration enhancement properties of the polymer systems. Morphological analysis, performed by light microscopy, transmission electron microscopy and CLSM, suggests a similar mechanism of penetration enhancement for both HCS and TMC solutions and for HCS nanoparticles. Such a mechanism probably involves a repackaging of the epithelial cells up to the basal membrane and a partial disarrangement of desmosomes. The cell viability and the nuclear integrity indicated on the semi-thin section stained with Toluidine blue and by CLSM analysis, respectively, suggest that HCS as a polymer solution and a nanoparticulate system, and TMC polymer solution, do not cause cell damage. Trimethyl chitosan and chitosan nanoparticulate systems were able to increase FD4 permeation across buccal epithelium to a greater extent than the chitosan solution.

FK778 does not impair intestinal allograft absorption in a preclinical model of total small bowel transplantation.

Malononitrilamide 715 (FK778), a new low-molecular weight immunosuppressant, inhibits both T-cell and B-cell function by acting on the pathway for de novo pyrimidine biosynthesis. Pyrimidines are important for intestinal trophism; their inhibition may predispose to metabolic and functional impairments, such as diarrhea and malabsorption. In this study we assessed the absorptive capacity of intestinal allografts in a large-animal model of small bowel transplantation (SBTx) in pigs chronically treated with FK778. Ten outbred pigs underwent total orthotopic SBTx. Immunosuppression consisted of oral tacrolimus (trough levels 5-15 ng/mL) and oral FK778 (4 mg/kg per day) administered for 60 days. The D-xylose absorption test was performed at day 60 to evaluate carbohydrate absorption. Results were compared to normal controls. Eight of the 10 animals were alive and in good condition at day 60. All of their allografts were free of rejection. The animals had a mean maximal weight loss of 6.4% during the study period; the final weight was comparable to the initial weight (P > .05). Diarrhea was present in all animals (mean 16% of postoperative days). The D-xylose curves showed that absorption in the transplanted animals at day 60 was similar to that in the untreated controls (P > .05). The absence of differences was confirmed by the statistical analysis. In conclusion, our preclinical study in pigs showed that chronic treatment with FK778 in combination with tacrolimus did not impair carbohydrate absorption by the allograft after SBTx.

Nelfinavir in HIV-HCV coinfected patients: a 24-month follow-up in a cohort of 82 patients.

This retrospective and longitudinal study evaluated the long-term hepatic tolerance of a nelfinavir (NFV)-antiretroviral combined regimen in 82 patients of the HCV-HIV Cohort of CISIH-Sud of Marseilles. Follow-up data (liver enzyme levels, CD4 cell count, HIV viral load, and metabolic parameters) of patients treated with NFV on inclusion or during the follow-up of the cohort were analyzed under treatment over 24 months. Comparisons were performed with X2 or Kruskal-Wallis tests. At baseline (n = 82), the median exposure to NFV was 4.1 months; 58 patients received NFV combined with NRTI and 24 with NNRTI. The median CD4 cell count was 337/mm3 [interquartile range (IR): 216-480) and 39.7% had an undetectable HIV RNA level. Qualitative HCV PCR was positive in 91% of the patients and 19/51 patients with liver biopsy were F3-F4. Median alanine and aspartate aminotransferase (ALAT, ASAT), gamma-glutamyltransferase (GT), and alkaline phosphatase (ALP) were 46 UI/liter (IR: 36-76), 55 UI/liter (IR: 32-97), 97 UI/liter (IR: 50-194), and 88 UI/liter (IR: 72-104), respectively, with 76% of the patients with ALAT/ASAT grade <2. Median follow-up was 23 months (IR: 13.8-37). No significant difference was observed in the distribution of ALAT, ASAT, GT, and ALP as well as of ALAT/ASAT grades over the 24-month study period. Patients treated with NFV + NNRTI had significantly higher GT and ALP levels at baseline with no significant increase during follow-up. Cholesterol, triglyceride, and glycemia distributions remained stable over time. In conclusion, this study showed a good hepatic and metabolic tolerance of a long-term NFV-combined regimen in HIV-HCV coinfected patients.

Reduction of oral acetaldehyde levels using a controlled-release chlorhexidine chip as a prevention strategy against upper digestive tract cancer.

Increasing evidence indicates a strong relationship exists between harmful habits like smoking and alcohol drinking and upper digestive tract cancer. In addition, smokers and alcohol drinkers also exhibit high salivary levels of carcinogenic acetaldehyde, the first metabolite of alcohol. This compound has been indicated as a major cancer causing factor in the upper digestive tract, especially among alcohol drinkers. Interestingly, acetaldehyde is produced from alcohol present in the epithelia by mucosal alcohol dehydrogenases (ADH) in the upper digestive tract. However, much higher levels derive from the bacterial oxidation of alcohol by the oral microflora. In this respect, the reduction of oral microbes can become a fundamental factor in diminishing the risk of cancer. In this article, we hypothesize that the antimicrobial agent chlorhexidine, formulated as controlled-release chip, and fixed by a dental device, (i.e., a modified orthodontic bracket), may be the most rational strategy for reducing acetaldehyde production by microflora.

The volatile fraction of cigarette smoke induces alterations in the human gingival fibroblast cytoskeleton.

Several in vitro investigations have indicated that the particulate phase of cigarette smoke, such as nicotine, affects many cell types, including gingival fibroblasts. However, few studies have been performed on the effects of the volatile fraction on the cellular structures that are involved in cell functions, such as adhesion and proliferation. Since the survival and reproduction of gingival fibroblasts are fundamental in maintaining the integrity of the oral connective tissue, as well as in wound healing, the effects on the cytoskeleton of acrolein and acetaldehyde, which are the volatile fractions of cigarette smoke, were examined in vitro for human gingival fibroblasts (HGFs). HGF strains that were taken from healthy subjects with non-inflamed-gingiva were utilized in this investigation. The cells were incubated in the presence of different concentrations of acrolein and acetaldehyde. Cell adhesion and viability were evaluated after incubation for 3 h and 5 days, respectively. The influence on cytoskeletal structures (tubulin, actin and vimentin intermediate filaments) was investigated with the indirect immunofluorescence technique. The results show that both substances produced similar effects, which resulted in a dose-dependent inhibition of HGF adhesion and viability. Disturbance of the HGF cytoskeleton consisted of disruption of the microtubules, actin filaments and vimentin microfilaments, which was accompanied by alterations to cell shape. Our experimental findings suggest that the volatile fractions of cigarette smoke, such as acrolein and acetaldehyde, have a cytotoxic effect on HGFs, with the result that they lose their capacity for adhesion and proliferation. The consequences of this could be impairment of the maintenance, integrity and remodelling of the oral connective tissue. According to our morphological evidence, these findings show that cigarette smoke can lead to the development and progression of periodontal disease, and indicate the need for appropriate therapy.

Human gingival fibroblast cytoskeleton is a target for volatile smoke components.

BACKGROUND: Several in vitro investigations have indicated that the particulate phase of cigarette smoke as nicotine affects many cell types including gingival fibroblasts, but few studies have examined the effect of volatile fraction on cellular structures involved in cell functions such as adhesion and proliferation. Since gingival fibroblast survival and reproduction are fundamental to maintaining the oral connective tissue as well as to wound healing, the effects of acrolein and acetaldehyde, volatile fractions of cigarette smoke, on cytoskeleton were examined in human gingival fibroblasts (HGFs) in vitro. METHODS: Human gingival fibroblast (HGF) strains from healthy subjects with non-inflamed gingiva were utilized. The cells were incubated in different concentrations of acrolein and acetaldehyde. Cell adhesion was evaluated after 3 hours. The influence of both substances on cytoskeletal structures, tubulin and vimentin intermediate filaments (VIF), was investigated using indirect immunofluorescence technique. RESULTS: The results show that both substances produced similar effects, resulting in a dose-dependent inhibition of HGF adhesion. Disturbance of HGF cytoskeleton consisted of a disruption of microtubules and vimentin microfilaments with alterations in cell shape. CONCLUSIONS: Our experimental findings suggest that volatile fractions of cigarette smoke such as acrolein and acetaldehyde, because their ability to bind and interact with the cytoskeleton, prevent HGF adhesion. Consequently the maintenance of the oral connective tissue and integrity and remodeling could be impaired. According to our morphological evidence, these findings confirm other clinical and epidemiological investigations reporting that volatile components of cigarette smoke could lead to the initiation and progression of periodontal disease.

Microtubules and vimentin associated filaments (VIFs) in cultured human gingival fibroblasts (HGFs) after exposure to acrolein and acetaldehyde.

Tobacco smoke, particularly its non-volatile fraction e. g. nicotine, is considered to be a major risk factor for the development and progression of periodontal disease. The purpose of this study has been to determine the effects of acrolein and acetaldehyde of the volatile fraction of tobacco smoking, on human gingival fibroblasts (HGFs) cultured in vitro with particular attention to cytoskeletal structures. A human gingival fibroblast strain derived from healthy gingiva was utilized in this study. The cells were exposed to acrolein and acetaldehyde at various concentrations. Control and treated cells were compared as regards their adhesion on cell culture dishes. Their cytoskeletal structures [tubulin and vimentin intermediate filaments (VIFs)] were examined by fluorescence microscopy. The results revealed that both substances produced similar effects resulting in a dose dependent decrease in cell adhesion and alterations of HGF cytoskeleton consisting of rearrangement and/or disruption of microtubules and vimentin associated filaments. Changes in cell shape and decrease in cell size were also seen. On the basis of this in vitro study, it appears that tobacco, through its volatile components, may directly affect the main functions of HGFs.

Fast one-dimensional profilometer with a compact disc pickup.

The use of compact disc (CD) pickups in optical profilometry is a well-established practice. The instruments currently available on the market are, however, expensive both to purchase and to maintain. This expense is mainly due to the high cost of the scanning system, and it makes the use of low-cost pickups fruitless. Moreover, translation stages are bulky, slow, and in most applications neither necessary nor desirable. We present a one-dimensional profilometer, which uses a CD pickup as both the sensor and the actuator. Beam scanning of the sample is in fact performed by the objective lens tracking motor. The device is cheap, fast, compact, light, and a valuable solution for fluid and hard-to-access surface profiling.

Ultrastructural changes in human gingival fibroblasts in vitro after exposure to vapour phase smoke components.

Tobacco and some of its volatile and non-volatile components have been found to affect many types of cells including gingival fibroblasts. Because normal gingival fibroblast functioning is fundamental to the maintenance of the oral connective tissue as well as to wound healing, we examined the effect of two vapour phase smoke components (acrolein and acetaldehyde) on proliferation and ultrastructure of human gingival fibroblasts (HGFs) in culture. A human gingival fibroblast strain derived from healthy individuals was used in this study. The cells were incubated in the presence of different concentrations of acrolein and acetaldehyde and cell proliferation and fine morphology were evaluated. The results show that acrolein and acetaldehyde produced dose dependent inhibition of HGF viability and alteration of cytoplasmic organelles. The main ultrastructural finding for the HGF cytoplasm was the presence of vacuoles and lysosomal structures which became prominent with increasing concentration of acrolein and acetaldehyde. Our results suggest that the ultrastructural alterations we observed in HGFs may be due to the uptake and storage of acrolein and acetaldehyde by the cells.

Volatile components of cigarette smoke: effect of acrolein and acetaldehyde on human gingival fibroblasts in vitro.

BACKGROUND: Tobacco and some of its volatile and non-volatile components have been found to affect many types of cells including gingival fibroblasts. Since normal gingival fibroblast functioning is fundamental to the maintenance of the periodontal connective tissue, as well as to wound healing, we examined the effect of acrolein and acetaldehyde, volatile components of cigarette smoke, on proliferation, attachment, and ultrastructure of human gingival fibroblasts (HGFs) in culture. METHODS: Human gingival fibroblast (HGF) strains derived from healthy individuals with non-inflamed gingiva were used in this study. The cells were incubated in the presence of different concentrations of acrolein and acetaldehyde. Cell attachment and proliferation were evaluated after incubation for 3 hours and 5 days, respectively. In addition, the cells were examined with a transmission electron microscope in order to evaluate their morphology. RESULTS: The results show that acrolein and acetaldehyde produced dose-dependent inhibition of HGF attachment and proliferation. The cytotoxic effect was, however, reversible when both substances were removed, after 3 days, from the medium. The main ultrastructural finding for the HGF cytoplasm was the presence of vacuoles and lysosomal structures that became prominent with increasing concentration of acrolein and acetaldehyde. CONCLUSIONS: Our experimental data suggest that acrolein and acetaldehyde, volatile components of tobacco smoke, are detrimental to HGF survival and consequently to the oral connective tissue. According to our morpho-functional evidence, these findings corroborate clinical and epidemiological investigations demonstrating smoke as a risk factor in the development of periodontal disease.