Characterization of fiber ultrashort pulse delivery for nonlinear endomicroscopy.

In this work, we present a detailed characterization of a small-core double-clad photonic crystal fiber, dedicated and approved for in vivo nonlinear imaging endomicroscopy. A numerical and experimental study has been performed to characterize the excitation and collection efficiencies through a 5 m-long optical fiber, including the pulse duration and spectral shape. This was first done without any distal optics, and then the performances of the system were studied by using two kinds of GRIN lenses at the fiber output. These results are compared to published data using commercial double clad fibers and GRIN lenses.

Physico-chemical characteristics of topsoil for contrasted forest, agricultural, urban and industrial land uses in France.

Soil quality is related to soil characteristics such as fertility and contamination. The aim of this study is to assess the effect of land use on these soil characteristics and to confirm the following anthropisation gradient: (i) forest, (ii) grassland, (iii) cultivated, (iv) orchard and vineyard, (v) urban vegetable garden, and (vi) SUITMA (urban, industrial, traffic, mining and military areas). A database comprising the characteristics of 2451 soils has been constituted. In order to compare the topsoils from six contrasting land uses, a principal components analysis (PCA) was performed on nine geochemical variables (C, N, pH, POlsen, total Cd, Cu, Ni, Pb, Zn). The first axis of the PCA is interpreted as a global increase of topsoil metallic elements along the anthropisation gradient. Axis 2 reflects the variability of fertility levels. Human activity increases the pressure on soils along the proposed gradient according to six different distribution patterns. This better knowledge of topsoil quality and its dependence on current land use should therefore help to manage and preserve the soil mantle.

Optimization and characterization of nonlinear excitation and collection through a gradient-index lens for high-resolution nonlinear endomicroscopy.

We report a study of gradient index (GRIN) lenses as a miniaturized micro-objective for in vivo imaging in the context of the development of a nonlinear endomicroscope. A numerical study of the parameters influencing the lateral resolution, excitation, and collection efficiency, when GRIN lens is coupled with a double clad fiber (DCF), is exposed. Four commercial DCFs, previously identified from the literature as potential endoscopic fibers, are simulated. Then, an experimental study characterizes two GRIN lenses (one commercial, one homemade) by their dispersion and nonlinear effects, potential intrinsic fluorescence, and use for fluorescence lifetime measurements. Images of neural cells from brain tissues of mice through a GRIN lens are presented.

[How to write, how to implement and how to evaluate a practice guideline in order to improve quality of care?]. / La qualité pour les nuls: de la rédaction d'un mode opératoire à son évaluation, en passant par sa mise en œuvre.

Initiatives of clinical practices improvement have been gradually developing in France for 20 years. Nevertheless, effective implementation of change is still difficult for numerous reasons. The use of clinical practices guidelines is one of the different ways of improvement. It is however necessary to adapt these national guidelines to the specificities of the hospital and the team, to ensure implementation and appropriation by the professionals. These recommendations are thus translated into applicable and concrete standard operating procedures. These documents have to be built by and for the concerned professionals. They are also communication and training tools, precise, directive, uniform in terms of presentation and attractive visually. Once drafted, they have to be distributed widely to the professionals to facilitate implementation. The simple distribution of the recommendations is insufficient to modify the clinical practices and require association of several methods of promotion for an optimal appropriation. How then to make sure of their effective use? Practices evaluation is one of the steps of continuous professional development, including continuous training and analysis of clinical practices by using methods promoted by the "Haute Autorité de santé". One of them is the clinical audit; use of method assessing non-pertinent treatment is interesting too. Analysis of the non-conformities and gaps between theory and practice allows identifying various possible causes (professional, institutional, organizational or personal) in order to implement corrective action plans, in a logic of continuous improvement.

[Serious adverse effects of blood collection]. / Effets indésirables donneurs et leur prise en charge.

The notification of serious adverse events occurring resulting from the collection of blood or blood components is a statutory requirement. The value of this set of surveillance procedures is the use of data collected. This article focuses on the organization of the French notification system, and the management of the main side effects known and reported.

Contrast-enhanced harmonic endoscopic ultrasound in solid lesions of the pancreas: results of a pilot study.

BACKGROUND AND STUDY AIMS: Distinguishing pancreatic adenocarcinoma from other pancreatic masses remains challenging with current imaging techniques. This prospective study aimed to evaluate the accuracy of a new procedure, imaging the microcirculation pattern of the pancreas by contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) with a new Olympus prototype echo endoscope. PATIENTS AND METHODS: 35 patients presenting with solid pancreatic lesions were prospectively enrolled. All patients had conventional B mode and power Doppler EUS. After an intravenous bolus injection of 2.4 ml of a second-generation ultrasound contrast agent (SonoVue) CEH-EUS was then performed with a new Olympus prototype echo endoscope (xGF-UCT 180). The microvascular pattern was compared with the final diagnosis based on the pathological examination of specimens from surgery or EUS-guided fine-needle aspiration (EUS-FNA) or on follow-up for at least 12 months. RESULTS: The final diagnoses were: 18 adenocarcinomas, 9 neuroendocrine tumors, 7 chronic pancreatitis, and 1 stromal tumor. Power Doppler failed to display microcirculation, whereas harmonic imaging demonstrated it in all cases. Out of 18 lesions with a hypointense signal on CEH-EUS, 16 were adenocarcinomas. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of hypointensity for diagnosing pancreatic adenocarcinoma were 89 %, 88 %, 88 %, 89 %, and 88.5 %, compared with corresponding values of 72 %, 100 %, 77 %, 100 %, and 86 % for EUS-FNA. Of five adenocarcinomas with false-negative results at EUS-FNA, four had a hypointense echo signal at CEH-EUS. CONCLUSIONS: CEH-EUS with the new Olympus prototype device successfully visualizes the microvascular pattern in pancreatic solid lesions, and may be useful for distinguishing adenocarcinomas from other pancreatic masses.

Miniprobe EUS in the pretherapeutic assessment of early esophageal neoplasia.

BACKGROUND AND STUDY AIMS: The high-frequency endosonography miniprobe has been advocated prior to endoscopic treatment of superficial esophageal neoplasm. We conducted a retrospective study, which summarized our clinical experience with various miniprobe techniques in the assessment of early squamous cell carcinoma (SCC) and superficial adenocarcinoma on Barrett's mucosa (SAB). PATIENTS AND METHODS: A total of 106 superficial and naive esophageal lesions were included in this series (52 SAB, 54 SCC). The results of the miniprobe staging were compared with pathology in order to determine the accuracy of this technique in differentiating mucosal from submucosal infiltration. Secondary aims were a comparison between the frequencies (20- vs. 30-MHz) and coupling methods (water-filled lumen vs. balloon-sheathed catheter) used. RESULTS: Overall accuracy, sensitivity, and specificity to differentiate T1sm from T1 m tumors were 73.5 %, 62 %, and 76.5 %, respectively. Overdiagnosis occurred in 18.6 % of the lesions. No statistically significant difference was found in the accuracy of the miniprobe staging between the two lesion types (SCC and SAB) ( P = 0.65), and results were significantly poorer in the distal part of the esophagus ( P = 0.00039). No significant difference was found between the two frequencies ( P = 0.51). Water-filled lumen proved to be superior to the balloon-sheathed catheter ( P = 0.015). CONCLUSION: High-frequency miniprobe examination has a limited accuracy in the detection of submucosal invasion in early esophageal cancer. Further improvements in acoustic coupling and ultrasound technique are required to improve the miniprobe accuracy before its implementation into clinical routine.

Endoscopic mucosal resection for squamous premalignant and early malignant lesions of the esophagus.

UNLABELLED: BACK AND STUDY AIMS: Endoscopic mucosal resection (EMR) is used to treat premalignant and malignant digestive tract lesions. This report presents the efficacy and safety of EMR for squamous superficial neoplastic esophageal lesions. PATIENTS AND METHODS: A retrospective cohort study presented data from 51 patients with 54 lesions over an 8-year period, between November 1997 and September 2005. Dysplasas or mucosal (m) T1 carcinomas were treated with repeated EMR until there was a complete local remission. Patients with submucosal (sm) T1 carcinomas were treated with repeated EMR until there was a complete local remission. Patients with submucosal (sm) T1 carcinomas or more advanced stage were offered surgery or chemoradiotherapy. RESULTS: There was no mortality, perforation, or major hemorrhage, and there were three easily dilated stenoses. Of the patients, 16 had lesions graded as T1sm or more advanced and one patient was found to have normal tissue post EMR. Complete local remission was achieved in 31 of the 34 patients with dysplasia or T1 m cancers (91%). There was no distant relapse and there was local disease recurrence in eight of the 31 patients (26%). The 5-year survival rate was 95%. CONCLUSIONS: EMR for squamous superficial neoplastic lesions of the esophagus is safe and provides satisfactory survival results.

Dynamic MR urography in urinary tract obstruction: implementation and preliminary results.

BACKGROUND: Recent studies have demonstrated magnetic resonance (MR) capabilities in evaluating renal morphology and function in patients with urinary obstruction. The objective of this report is to support the introduction of dynamic MR renography on any MR equipment. METHODS: A custom-made device of vials filled with different concentrations of gadolinium was studied by combinations of T1-weighted gradient-echo sequences and coils. We compared the capabilities of two coils (phased array vs. standard body), the properties of dynamic sequences, and the effects of increasing concentrations of gadolinium on signal intensity. In a second section, we designed MR urography plug-ins of Image J (DICOM image software) for the analysis of dynamic studies. RESULTS: Optimized gradient-echo sequences acquired with a phased array body coil produced acceptable quality images with a linear relation between signal intensity and the lowest concentrations of gadolinium. In vitro measurements showed loss of linearity above 8 mmol/L. CONCLUSION: Theoretical calculation and data from the literature suggest that the gadolinium dose to the patient should not exceed one-fourth of the usual one (0.025 mmol/kg). Postprocessing using Image J software and the specifically designed plug-ins was validated. The collection of plug-ins is now available on the Internet.

Hypocaloric diet reduces exercise-induced alpha 2-adrenergic antilipolytic effect and alpha 2-adrenergic receptor mRNA levels in adipose tissue of obese women.

Previous investigations have shown that alpha 2-adrenoceptor (alpha 2-AR) stimulation blunts lipid mobilization during physiological activation of the sympathetic nervous system promoted by exercise in sc abdominal adipose tissue (SCAAT) in obese men. To investigate the effect of a low calorie diet (LCD) on the alpha 2-adrenergic responsiveness and on the expression of alpha 2-AR and beta 2-adrenoceptor (beta 2-AR) in SCAAT, 11 obese women (weight: 99.1 +/- 4.6 kg; body mass index: 34.3 +/- 1.1 kg/m(2)) received a 12-wk diet providing 500 kcal/d less than their usual diet. The exercise-induced alpha 2-adrenergic antilipolytic effect was investigated in SCAAT before and at the end of LCD. Changes in extracellular glycerol concentration and local blood flow were measured in SCAAT during a 45-min exercise bout (50% of heart rate reserve) using a control microdialysis probe and a probe supplemented with the alpha2-AR antagonist phentolamine. SCAAT biopsies were performed for determination of mRNA levels using RT-competitive PCR. Plasma catecholamine responses to exercise bout were not different before and at the end of LCD. Before LCD, the exercise-induced increase in extracellular glycerol concentration was potentiated by phentolamine supplementation, while this potentiating effect of the alpha-antagonist was not observed at the end of LCD. No changes were observed for beta 2-AR and hormone-sensitive lipase mRNA levels, while alpha 2-AR mRNA level was significantly decreased in adipose tissue during LCD. These findings show that alpha 2-AR-mediated antilipolytic action is reduced by a moderate hypocaloric diet and that down-regulation of alpha 2-AR mRNA levels may participate in the decrease of the alpha 2-adrenergic effect revealed by microdialysis.

[Ischemic orchiditis: review of 5 cases diagnosed by color Doppler ultrasonography]. / Orchites ischémiques: A propos de 5 cas diagnostiqués en écho-Doppler couleur.

PURPOSE: To study color-doppler ultrasoundfeatures of testicular infarction caused by orchiepididymitis, a severe complication of orchiepididymitis. MATERIAL: and Methods. Five patients were included over a 2 year period. All presented with more than 24 hours of pain. A final diagnosis of testicular infarction caused by orchiepididymitis and color doppler ultrasound was available in all cases. RESULTS: All patients showed doppler ultrasound signs of testicular ischemia. Either vascularisation was not detectable or intratesticular resistive index was increased with a negative diastolic flow. Orchidectomy was performed in all patients. CONCLUSION: Color doppler examination of the scrotum should include measurement of intratesticular resistive index. An elevated RI can be suggestive of ischemia.

[Cost of transfusion in AIDS. Experience at the Claude-Bernard Hospital apropos of 28 cases]. / Coût transfusionnel du SIDA. Expérience de l'hôpital Claude-Bernard à propos de 28 cas.

The study of 28 confirmed cases of AIDS shows that transfused patients use a large amount of hospital's blood products, especially platelets. For these patients, the average cost of transfusion is higher than that, for intensive care unit patient's. The use of irradiated products increases the cost (+ 35%). As there is a shortage of donors, if the present precautions are respected, there is no reason why the hospital should not continue to ask the patient's family and circle of friends, to donate blood.